1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB now has experimental support for the compilation and injection of
7 C++ source code into the inferior. This beta release does not include
8 support for several language features, such as templates, constructors,
11 This feature requires GCC 7.1 or higher built with libcp1.so
14 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
15 can be passed using the '[ADDRESS]:PORT' notation, or the regular
16 'ADDRESS:PORT' method.
18 * DWARF index cache: GDB can now automatically save indices of DWARF
19 symbols on disk to speed up further loading of the same binaries.
21 * GDB in batch mode now exits with status 1 if the last command to be
24 * Changes to the "frame", "select-frame", and "info frame" CLI
25 commands. These commands all now take a frame specification which
26 is either a frame level, or one of the keywords 'level', 'address',
27 'function', or 'view' followed by a parameter. Selecting a frame by
28 address, or viewing a frame outside the current backtrace now
29 requires the use of a keyword. Selecting a frame by level is
30 unchanged. The MI comment "-stack-select-frame" is unchanged.
34 set debug compile-cplus-types
35 show debug compile-cplus-types
36 Control the display of debug output about type conversion in the
37 C++ compile feature. Commands have no effect while compiliong
42 Control whether debug output about files/functions skipping is
45 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
46 Apply a command to some frames.
47 FLAG arguments allow to control what output to produce and how to handle
48 errors raised when applying COMMAND to a frame.
51 Apply a command to all threads (ignoring errors and empty output).
52 Shortcut for 'thread apply all -s COMMAND'.
55 Apply a command to all frames (ignoring errors and empty output).
56 Shortcut for 'frame apply all -s COMMAND'.
59 Apply a command to all frames of all threads (ignoring errors and empty
61 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
63 maint set dwarf unwinders (on|off)
64 maint show dwarf unwinders
65 Control whether DWARF unwinders can be used.
68 Display a list of open files for a process.
72 target remote FILENAME
73 target extended-remote FILENAME
74 If FILENAME is a Unix domain socket, GDB will attempt to connect
75 to this socket instead of opening FILENAME as a character device.
77 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
78 The 'thread apply' command accepts new FLAG arguments.
79 FLAG arguments allow to control what output to produce and how to handle
80 errors raised when applying COMMAND to a thread.
82 set tui tab-width NCHARS
83 show tui tab-width NCHARS
84 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
88 ** The '-data-disassemble' MI command now accepts an '-a' option to
89 disassemble the whole function surrounding the given program
90 counter value or function name. Support for this feature can be
91 verified by using the "-list-features" command, which should
92 contain "data-disassemble-a-option".
94 ** Command responses and notifications that include a frame now include
95 the frame's architecture in a new "arch" attribute.
97 * New native configurations
99 GNU/Linux/RISC-V riscv*-*-linux*
100 FreeBSD/riscv riscv*-*-freebsd*
104 GNU/Linux/RISC-V riscv*-*-linux*
106 CSKY GNU/LINUX csky*-*-linux
107 FreeBSD/riscv riscv*-*-freebsd*
111 ** The gdb.Inferior type has a new 'progspace' property, which is the program
112 space associated to that inferior.
114 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
115 of objfiles associated to that program space.
117 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
118 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
121 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
122 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
123 correct and did not work properly.
129 Enable or disable the undefined behavior sanitizer. This is
130 disabled by default, but passing --enable-ubsan=yes or
131 --enable-ubsan=auto to configure will enable it. Enabling this can
132 cause a performance penalty. The undefined behavior sanitizer was
133 first introduced in GCC 4.9.
135 *** Changes in GDB 8.2
137 * The 'set disassembler-options' command now supports specifying options
140 * The 'symbol-file' command now accepts an '-o' option to add a relative
141 offset to all sections.
143 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
144 a relative offset to all sections, but it allows to override the load
145 address of individual sections using '-s'.
147 * The 'add-symbol-file' command no longer requires the second argument
148 (address of the text section).
150 * The endianness used with the 'set endian auto' mode in the absence of
151 an executable selected for debugging is now the last endianness chosen
152 either by one of the 'set endian big' and 'set endian little' commands
153 or by inferring from the last executable used, rather than the startup
156 * The pager now allows a "c" response, meaning to disable the pager
157 for the rest of the current command.
159 * The commands 'info variables/functions/types' now show the source line
160 numbers of symbol definitions when available.
162 * 'info proc' now works on running processes on FreeBSD systems and core
163 files created on FreeBSD systems.
165 * C expressions can now use _Alignof, and C++ expressions can now use
168 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
169 the vector length while the process is running.
175 Control display of debugging info regarding the FreeBSD native target.
177 set|show varsize-limit
178 This new setting allows the user to control the maximum size of Ada
179 objects being printed when those objects have a variable type,
180 instead of that maximum size being hardcoded to 65536 bytes.
182 set|show record btrace cpu
183 Controls the processor to be used for enabling errata workarounds for
186 maint check libthread-db
187 Run integrity checks on the current inferior's thread debugging
190 maint set check-libthread-db (on|off)
191 maint show check-libthread-db
192 Control whether to run integrity checks on inferior specific thread
193 debugging libraries as they are loaded. The default is not to
198 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
200 ** The commands attached to a breakpoint can be set by assigning to
201 the breakpoint's "commands" field.
203 ** gdb.execute can now execute multi-line gdb commands.
205 ** The new functions gdb.convenience_variable and
206 gdb.set_convenience_variable can be used to get and set the value
207 of convenience variables.
209 ** A gdb.Parameter will no longer print the "set" help text on an
210 ordinary "set"; instead by default a "set" will be silent unless
211 the get_set_string method returns a non-empty string.
215 RiscV ELF riscv*-*-elf
217 * Removed targets and native configurations
219 m88k running OpenBSD m88*-*-openbsd*
220 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
221 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
222 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
224 * Aarch64/Linux hardware watchpoints improvements
226 Hardware watchpoints on unaligned addresses are now properly
227 supported when running Linux kernel 4.10 or higher: read and access
228 watchpoints are no longer spuriously missed, and all watchpoints
229 lengths between 1 and 8 bytes are supported. On older kernels,
230 watchpoints set on unaligned addresses are no longer missed, with
231 the tradeoff that there is a possibility of false hits being
236 --enable-codesign=CERT
237 This can be used to invoke "codesign -s CERT" after building gdb.
238 This option is useful on macOS, where code signing is required for
239 gdb to work properly.
241 --disable-gdbcli has been removed
242 This is now silently accepted, but does nothing.
244 *** Changes in GDB 8.1
246 * GDB now supports dynamically creating arbitrary register groups specified
247 in XML target descriptions. This allows for finer grain grouping of
248 registers on systems with a large amount of registers.
250 * The 'ptype' command now accepts a '/o' flag, which prints the
251 offsets and sizes of fields in a struct, like the pahole(1) tool.
253 * New "--readnever" command line option instructs GDB to not read each
254 symbol file's symbolic debug information. This makes startup faster
255 but at the expense of not being able to perform symbolic debugging.
256 This option is intended for use cases where symbolic debugging will
257 not be used, e.g., when you only need to dump the debuggee's core.
259 * GDB now uses the GNU MPFR library, if available, to emulate target
260 floating-point arithmetic during expression evaluation when the target
261 uses different floating-point formats than the host. At least version
262 3.1 of GNU MPFR is required.
264 * GDB now supports access to the guarded-storage-control registers and the
265 software-based guarded-storage broadcast control registers on IBM z14.
267 * On Unix systems, GDB now supports transmitting environment variables
268 that are to be set or unset to GDBserver. These variables will
269 affect the environment to be passed to the remote inferior.
271 To inform GDB of environment variables that are to be transmitted to
272 GDBserver, use the "set environment" command. Only user set
273 environment variables are sent to GDBserver.
275 To inform GDB of environment variables that are to be unset before
276 the remote inferior is started by the GDBserver, use the "unset
277 environment" command.
279 * Completion improvements
281 ** GDB can now complete function parameters in linespecs and
282 explicit locations without quoting. When setting breakpoints,
283 quoting around functions names to help with TAB-completion is
284 generally no longer necessary. For example, this now completes
287 (gdb) b function(in[TAB]
288 (gdb) b function(int)
290 Related, GDB is no longer confused with completing functions in
291 C++ anonymous namespaces:
294 (gdb) b (anonymous namespace)::[TAB][TAB]
295 (anonymous namespace)::a_function()
296 (anonymous namespace)::b_function()
298 ** GDB now has much improved linespec and explicit locations TAB
299 completion support, that better understands what you're
300 completing and offers better suggestions. For example, GDB no
301 longer offers data symbols as possible completions when you're
302 setting a breakpoint.
304 ** GDB now TAB-completes label symbol names.
306 ** The "complete" command now mimics TAB completion accurately.
308 * New command line options (gcore)
311 Dump all memory mappings.
313 * Breakpoints on C++ functions are now set on all scopes by default
315 By default, breakpoints on functions/methods are now interpreted as
316 specifying all functions with the given name ignoring missing
317 leading scopes (namespaces and classes).
319 For example, assuming a C++ program with symbols named:
324 both commands "break func()" and "break B::func()" set a breakpoint
327 You can use the new flag "-qualified" to override this. This makes
328 GDB interpret the specified function name as a complete
329 fully-qualified name instead. For example, using the same C++
330 program, the "break -q B::func" command sets a breakpoint on
331 "B::func", only. A parameter has been added to the Python
332 gdb.Breakpoint constructor to achieve the same result when creating
333 a breakpoint from Python.
335 * Breakpoints on functions marked with C++ ABI tags
337 GDB can now set breakpoints on functions marked with C++ ABI tags
338 (e.g., [abi:cxx11]). See here for a description of ABI tags:
339 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
341 Functions with a C++11 abi tag are demangled/displayed like this:
343 function[abi:cxx11](int)
346 You can now set a breakpoint on such functions simply as if they had
349 (gdb) b function(int)
351 Or if you need to disambiguate between tags, like:
353 (gdb) b function[abi:other_tag](int)
355 Tab completion was adjusted accordingly as well.
359 ** New events gdb.new_inferior, gdb.inferior_deleted, and
360 gdb.new_thread are emitted. See the manual for further
361 description of these.
363 ** A new function, "gdb.rbreak" has been added to the Python API.
364 This function allows the setting of a large number of breakpoints
365 via a regex pattern in Python. See the manual for further details.
367 ** Python breakpoints can now accept explicit locations. See the
368 manual for a further description of this feature.
371 * New features in the GDB remote stub, GDBserver
373 ** GDBserver is now able to start inferior processes with a
374 specified initial working directory.
376 The user can set the desired working directory to be used from
377 GDB using the new "set cwd" command.
379 ** New "--selftest" command line option runs some GDBserver self
380 tests. These self tests are disabled in releases.
382 ** On Unix systems, GDBserver now does globbing expansion and variable
383 substitution in inferior command line arguments.
385 This is done by starting inferiors using a shell, like GDB does.
386 See "set startup-with-shell" in the user manual for how to disable
387 this from GDB when using "target extended-remote". When using
388 "target remote", you can disable the startup with shell by using the
389 new "--no-startup-with-shell" GDBserver command line option.
391 ** On Unix systems, GDBserver now supports receiving environment
392 variables that are to be set or unset from GDB. These variables
393 will affect the environment to be passed to the inferior.
395 * When catching an Ada exception raised with a message, GDB now prints
396 the message in the catchpoint hit notification. In GDB/MI mode, that
397 information is provided as an extra field named "exception-message"
398 in the *stopped notification.
400 * Trait objects can now be inspected When debugging Rust code. This
401 requires compiler support which will appear in Rust 1.24.
405 QEnvironmentHexEncoded
406 Inform GDBserver of an environment variable that is to be passed to
407 the inferior when starting it.
410 Inform GDBserver of an environment variable that is to be unset
411 before starting the remote inferior.
414 Inform GDBserver that the environment should be reset (i.e.,
415 user-set environment variables should be unset).
418 Indicates whether the inferior must be started with a shell or not.
421 Tell GDBserver that the inferior to be started should use a specific
424 * The "maintenance print c-tdesc" command now takes an optional
425 argument which is the file name of XML target description.
427 * The "maintenance selftest" command now takes an optional argument to
428 filter the tests to be run.
430 * The "enable", and "disable" commands now accept a range of
431 breakpoint locations, e.g. "enable 1.3-5".
436 Set and show the current working directory for the inferior.
439 Set and show compilation command used for compiling and injecting code
440 with the 'compile' commands.
442 set debug separate-debug-file
443 show debug separate-debug-file
444 Control the display of debug output about separate debug file search.
446 set dump-excluded-mappings
447 show dump-excluded-mappings
448 Control whether mappings marked with the VM_DONTDUMP flag should be
449 dumped when generating a core file.
452 List the registered selftests.
455 Start the debugged program stopping at the first instruction.
458 Control display of debugging messages related to OpenRISC targets.
460 set|show print type nested-type-limit
461 Set and show the limit of nesting level for nested types that the
462 type printer will show.
464 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
467 * Safer/improved support for debugging with no debug info
469 GDB no longer assumes functions with no debug information return
472 This means that GDB now refuses to call such functions unless you
473 tell it the function's type, by either casting the call to the
474 declared return type, or by casting the function to a function
475 pointer of the right type, and calling that:
477 (gdb) p getenv ("PATH")
478 'getenv' has unknown return type; cast the call to its declared return type
479 (gdb) p (char *) getenv ("PATH")
480 $1 = 0x7fffffffe "/usr/local/bin:/"...
481 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
482 $2 = 0x7fffffffe "/usr/local/bin:/"...
484 Similarly, GDB no longer assumes that global variables with no debug
485 info have type 'int', and refuses to print the variable's value
486 unless you tell it the variable's type:
489 'var' has unknown type; cast it to its declared type
493 * New native configurations
495 FreeBSD/aarch64 aarch64*-*-freebsd*
496 FreeBSD/arm arm*-*-freebsd*
500 FreeBSD/aarch64 aarch64*-*-freebsd*
501 FreeBSD/arm arm*-*-freebsd*
502 OpenRISC ELF or1k*-*-elf
504 * Removed targets and native configurations
506 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
508 *** Changes in GDB 8.0
510 * GDB now supports access to the PKU register on GNU/Linux. The register is
511 added by the Memory Protection Keys for Userspace feature which will be
512 available in future Intel CPUs.
514 * GDB now supports C++11 rvalue references.
518 ** New functions to start, stop and access a running btrace recording.
519 ** Rvalue references are now supported in gdb.Type.
521 * GDB now supports recording and replaying rdrand and rdseed Intel 64
524 * Building GDB and GDBserver now requires a C++11 compiler.
526 For example, GCC 4.8 or later.
528 It is no longer possible to build GDB or GDBserver with a C
529 compiler. The --disable-build-with-cxx configure option has been
532 * Building GDB and GDBserver now requires GNU make >= 3.81.
534 It is no longer supported to build GDB or GDBserver with another
535 implementation of the make program or an earlier version of GNU make.
537 * Native debugging on MS-Windows supports command-line redirection
539 Command-line arguments used for starting programs on MS-Windows can
540 now include redirection symbols supported by native Windows shells,
541 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
542 as "run", "start", and "set args", as well as the corresponding MI
545 * Support for thread names on MS-Windows.
547 GDB now catches and handles the special exception that programs
548 running on MS-Windows use to assign names to threads in the
551 * Support for Java programs compiled with gcj has been removed.
553 * User commands now accept an unlimited number of arguments.
554 Previously, only up to 10 was accepted.
556 * The "eval" command now expands user-defined command arguments.
558 This makes it easier to process a variable number of arguments:
563 eval "print $arg%d", $i
568 * Target descriptions can now describe registers for sparc32 and sparc64.
570 * GDB now supports DWARF version 5 (debug information format).
571 Its .debug_names index is not yet supported.
573 * New native configurations
575 FreeBSD/mips mips*-*-freebsd
579 Synopsys ARC arc*-*-elf32
580 FreeBSD/mips mips*-*-freebsd
582 * Removed targets and native configurations
584 Alpha running FreeBSD alpha*-*-freebsd*
585 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
590 Erases all the flash memory regions reported by the target.
592 maint print arc arc-instruction address
593 Print internal disassembler information about instruction at a given address.
597 set disassembler-options
598 show disassembler-options
599 Controls the passing of target specific information to the disassembler.
600 If it is necessary to specify more than one disassembler option then
601 multiple options can be placed together into a comma separated list.
602 The default value is the empty string. Currently, the only supported
603 targets are ARM, PowerPC and S/390.
608 Erases all the flash memory regions reported by the target. This is
609 equivalent to the CLI command flash-erase.
611 -file-list-shared-libraries
612 List the shared libraries in the program. This is
613 equivalent to the CLI command "info shared".
616 Catchpoints stopping the program when Ada exceptions are
617 handled. This is equivalent to the CLI command "catch handlers".
619 *** Changes in GDB 7.12
621 * GDB and GDBserver now build with a C++ compiler by default.
623 The --enable-build-with-cxx configure option is now enabled by
624 default. One must now explicitly configure with
625 --disable-build-with-cxx in order to build with a C compiler. This
626 option will be removed in a future release.
628 * GDBserver now supports recording btrace without maintaining an active
631 * GDB now supports a negative repeat count in the 'x' command to examine
632 memory backward from the given address. For example:
635 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
636 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
637 (gdb) x/-5i 0x0000000000400580
638 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
639 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
640 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
641 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
642 0x40057b <main(int, char**)+25>:
643 callq 0x400536 <Func1(int, char const*)>
645 * Fortran: Support structures with fields of dynamic types and
646 arrays of dynamic types.
648 * The symbol dumping maintenance commands have new syntax.
649 maint print symbols [-pc address] [--] [filename]
650 maint print symbols [-objfile objfile] [-source source] [--] [filename]
651 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
652 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
653 maint print msymbols [-objfile objfile] [--] [filename]
655 * GDB now supports multibit bitfields and enums in target register
658 * New Python-based convenience function $_as_string(val), which returns
659 the textual representation of a value. This function is especially
660 useful to obtain the text label of an enum value.
662 * Intel MPX bound violation handling.
664 Segmentation faults caused by a Intel MPX boundary violation
665 now display the kind of violation (upper or lower), the memory
666 address accessed and the memory bounds, along with the usual
667 signal received and code location.
671 Program received signal SIGSEGV, Segmentation fault
672 Upper bound violation while accessing address 0x7fffffffc3b3
673 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
674 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
676 * Rust language support.
677 GDB now supports debugging programs written in the Rust programming
678 language. See https://www.rust-lang.org/ for more information about
681 * Support for running interpreters on specified input/output devices
683 GDB now supports a new mechanism that allows frontends to provide
684 fully featured GDB console views, as a better alternative to
685 building such views on top of the "-interpreter-exec console"
686 command. See the new "new-ui" command below. With that command,
687 frontends can now start GDB in the traditional command-line mode
688 running in an embedded terminal emulator widget, and create a
689 separate MI interpreter running on a specified i/o device. In this
690 way, GDB handles line editing, history, tab completion, etc. in the
691 console all by itself, and the GUI uses the separate MI interpreter
692 for its own control and synchronization, invisible to the command
695 * The "catch syscall" command catches groups of related syscalls.
697 The "catch syscall" command now supports catching a group of related
698 syscalls using the 'group:' or 'g:' prefix.
703 skip -gfile file-glob-pattern
704 skip -function function
705 skip -rfunction regular-expression
706 A generalized form of the skip command, with new support for
707 glob-style file names and regular expressions for function names.
708 Additionally, a file spec and a function spec may now be combined.
710 maint info line-table REGEXP
711 Display the contents of GDB's internal line table data struture.
714 Run any GDB unit tests that were compiled in.
717 Start a new user interface instance running INTERP as interpreter,
718 using the TTY file for input/output.
722 ** gdb.Breakpoint objects have a new attribute "pending", which
723 indicates whether the breakpoint is pending.
724 ** Three new breakpoint-related events have been added:
725 gdb.breakpoint_created, gdb.breakpoint_modified, and
726 gdb.breakpoint_deleted.
729 Signal ("set") the given MS-Windows event object. This is used in
730 conjunction with the Windows JIT debugging (AeDebug) support, where
731 the OS suspends a crashing process until a debugger can attach to
732 it. Resuming the crashing process, in order to debug it, is done by
735 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
736 was added in GDBserver, including JIT compiling fast tracepoint's
737 conditional expression bytecode into native code.
739 * Support for various remote target protocols and ROM monitors has
742 target m32rsdi Remote M32R debugging over SDI
743 target mips MIPS remote debugging protocol
744 target pmon PMON ROM monitor
745 target ddb NEC's DDB variant of PMON for Vr4300
746 target rockhopper NEC RockHopper variant of PMON
747 target lsi LSI variant of PMO
749 * Support for tracepoints and fast tracepoints on powerpc-linux,
750 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
751 including JIT compiling fast tracepoint's conditional expression
752 bytecode into native code.
754 * MI async record =record-started now includes the method and format used for
755 recording. For example:
757 =record-started,thread-group="i1",method="btrace",format="bts"
759 * MI async record =thread-selected now includes the frame field. For example:
761 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
765 Andes NDS32 nds32*-*-elf
767 *** Changes in GDB 7.11
769 * GDB now supports debugging kernel-based threads on FreeBSD.
771 * Per-inferior thread numbers
773 Thread numbers are now per inferior instead of global. If you're
774 debugging multiple inferiors, GDB displays thread IDs using a
775 qualified INF_NUM.THR_NUM form. For example:
779 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
780 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
781 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
782 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
784 As consequence, thread numbers as visible in the $_thread
785 convenience variable and in Python's InferiorThread.num attribute
786 are no longer unique between inferiors.
788 GDB now maintains a second thread ID per thread, referred to as the
789 global thread ID, which is the new equivalent of thread numbers in
790 previous releases. See also $_gthread below.
792 For backwards compatibility, MI's thread IDs always refer to global
795 * Commands that accept thread IDs now accept the qualified
796 INF_NUM.THR_NUM form as well. For example:
799 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
802 * In commands that accept a list of thread IDs, you can now refer to
803 all threads of an inferior using a star wildcard. GDB accepts
804 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
805 refer to all threads of the current inferior. For example, "info
808 * You can use "info threads -gid" to display the global thread ID of
811 * The new convenience variable $_gthread holds the global number of
814 * The new convenience variable $_inferior holds the number of the
817 * GDB now displays the ID and name of the thread that hit a breakpoint
818 or received a signal, if your program is multi-threaded. For
821 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
822 Thread 1 "main" received signal SIGINT, Interrupt.
824 * Record btrace now supports non-stop mode.
826 * Support for tracepoints on aarch64-linux was added in GDBserver.
828 * The 'record instruction-history' command now indicates speculative execution
829 when using the Intel Processor Trace recording format.
831 * GDB now allows users to specify explicit locations, bypassing
832 the linespec parser. This feature is also available to GDB/MI
835 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
836 GDB now is able to debug both AArch64 applications and ARM applications
839 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
840 including JIT compiling fast tracepoint's conditional expression bytecode
843 * GDB now supports displaced stepping on AArch64 GNU/Linux.
845 * "info threads", "info inferiors", "info display", "info checkpoints"
846 and "maint info program-spaces" now list the corresponding items in
847 ascending ID order, for consistency with all other "info" commands.
849 * In Ada, the overloads selection menu has been enhanced to display the
850 parameter types and the return types for the matching overloaded subprograms.
854 maint set target-non-stop (on|off|auto)
855 maint show target-non-stop
856 Control whether GDB targets always operate in non-stop mode even if
857 "set non-stop" is "off". The default is "auto", meaning non-stop
858 mode is enabled if supported by the target.
860 maint set bfd-sharing
861 maint show bfd-sharing
862 Control the reuse of bfd objects.
866 Control display of debugging info regarding bfd caching.
870 Control display of debugging info regarding FreeBSD threads.
872 set remote multiprocess-extensions-packet
873 show remote multiprocess-extensions-packet
874 Set/show the use of the remote protocol multiprocess extensions.
876 set remote thread-events
877 show remote thread-events
878 Set/show the use of thread create/exit events.
880 set ada print-signatures on|off
881 show ada print-signatures"
882 Control whether parameter types and return types are displayed in overloads
883 selection menus. It is activaled (@code{on}) by default.
887 Controls the maximum size of memory, in bytes, that GDB will
888 allocate for value contents. Prevents incorrect programs from
889 causing GDB to allocate overly large buffers. Default is 64k.
891 * The "disassemble" command accepts a new modifier: /s.
892 It prints mixed source+disassembly like /m with two differences:
893 - disassembled instructions are now printed in program order, and
894 - and source for all relevant files is now printed.
895 The "/m" option is now considered deprecated: its "source-centric"
896 output hasn't proved useful in practice.
898 * The "record instruction-history" command accepts a new modifier: /s.
899 It behaves exactly like /m and prints mixed source+disassembly.
901 * The "set scheduler-locking" command supports a new mode "replay".
902 It behaves like "off" in record mode and like "on" in replay mode.
904 * Support for various ROM monitors has been removed:
906 target dbug dBUG ROM monitor for Motorola ColdFire
907 target picobug Motorola picobug monitor
908 target dink32 DINK32 ROM monitor for PowerPC
909 target m32r Renesas M32R/D ROM monitor
910 target mon2000 mon2000 ROM monitor
911 target ppcbug PPCBUG ROM monitor for PowerPC
913 * Support for reading/writing memory and extracting values on architectures
914 whose memory is addressable in units of any integral multiple of 8 bits.
917 Allows to break when an Ada exception is handled.
922 Indicates that an exec system call was executed.
924 exec-events feature in qSupported
925 The qSupported packet allows GDB to request support for exec
926 events using the new 'gdbfeature' exec-event, and the qSupported
927 response can contain the corresponding 'stubfeature'. Set and
928 show commands can be used to display whether these features are enabled.
931 Equivalent to interrupting with the ^C character, but works in
934 thread created stop reason (T05 create:...)
935 Indicates that the thread was just created and is stopped at entry.
937 thread exit stop reply (w exitcode;tid)
938 Indicates that the thread has terminated.
941 Enables/disables thread create and exit event reporting. For
942 example, this is used in non-stop mode when GDB stops a set of
943 threads and synchronously waits for the their corresponding stop
944 replies. Without exit events, if one of the threads exits, GDB
945 would hang forever not knowing that it should no longer expect a
946 stop for that same thread.
949 Indicates that there are no resumed threads left in the target (all
950 threads are stopped). The remote stub reports support for this stop
951 reply to GDB's qSupported query.
954 Enables/disables catching syscalls from the inferior process.
955 The remote stub reports support for this packet to GDB's qSupported query.
957 syscall_entry stop reason
958 Indicates that a syscall was just called.
960 syscall_return stop reason
961 Indicates that a syscall just returned.
963 * Extended-remote exec events
965 ** GDB now has support for exec events on extended-remote Linux targets.
966 For such targets with Linux kernels 2.5.46 and later, this enables
967 follow-exec-mode and exec catchpoints.
969 set remote exec-event-feature-packet
970 show remote exec-event-feature-packet
971 Set/show the use of the remote exec event feature.
973 * Thread names in remote protocol
975 The reply to qXfer:threads:read may now include a name attribute for each
978 * Target remote mode fork and exec events
980 ** GDB now has support for fork and exec events on target remote mode
981 Linux targets. For such targets with Linux kernels 2.5.46 and later,
982 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
983 fork and exec catchpoints.
985 * Remote syscall events
987 ** GDB now has support for catch syscall on remote Linux targets,
988 currently enabled on x86/x86_64 architectures.
990 set remote catch-syscall-packet
991 show remote catch-syscall-packet
992 Set/show the use of the remote catch syscall feature.
996 ** The -var-set-format command now accepts the zero-hexadecimal
997 format. It outputs data in hexadecimal format with zero-padding on the
1002 ** gdb.InferiorThread objects have a new attribute "global_num",
1003 which refers to the thread's global thread ID. The existing
1004 "num" attribute now refers to the thread's per-inferior number.
1005 See "Per-inferior thread numbers" above.
1006 ** gdb.InferiorThread objects have a new attribute "inferior", which
1007 is the Inferior object the thread belongs to.
1009 *** Changes in GDB 7.10
1011 * Support for process record-replay and reverse debugging on aarch64*-linux*
1012 targets has been added. GDB now supports recording of A64 instruction set
1013 including advance SIMD instructions.
1015 * Support for Sun's version of the "stabs" debug file format has been removed.
1017 * GDB now honors the content of the file /proc/PID/coredump_filter
1018 (PID is the process ID) on GNU/Linux systems. This file can be used
1019 to specify the types of memory mappings that will be included in a
1020 corefile. For more information, please refer to the manual page of
1021 "core(5)". GDB also has a new command: "set use-coredump-filter
1022 on|off". It allows to set whether GDB will read the content of the
1023 /proc/PID/coredump_filter file when generating a corefile.
1025 * The "info os" command on GNU/Linux can now display information on
1027 "info os cpus" Listing of all cpus/cores on the system
1029 * GDB has two new commands: "set serial parity odd|even|none" and
1030 "show serial parity". These allows to set or show parity for the
1033 * The "info source" command now displays the producer string if it was
1034 present in the debug info. This typically includes the compiler version
1035 and may include things like its command line arguments.
1037 * The "info dll", an alias of the "info sharedlibrary" command,
1038 is now available on all platforms.
1040 * Directory names supplied to the "set sysroot" commands may be
1041 prefixed with "target:" to tell GDB to access shared libraries from
1042 the target system, be it local or remote. This replaces the prefix
1043 "remote:". The default sysroot has been changed from "" to
1044 "target:". "remote:" is automatically converted to "target:" for
1045 backward compatibility.
1047 * The system root specified by "set sysroot" will be prepended to the
1048 filename of the main executable (if reported to GDB as absolute by
1049 the operating system) when starting processes remotely, and when
1050 attaching to already-running local or remote processes.
1052 * GDB now supports automatic location and retrieval of executable
1053 files from remote targets. Remote debugging can now be initiated
1054 using only a "target remote" or "target extended-remote" command
1055 (no "set sysroot" or "file" commands are required). See "New remote
1058 * The "dump" command now supports verilog hex format.
1060 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1062 * On GNU/Linux, GDB and gdbserver are now able to access executable
1063 and shared library files without a "set sysroot" command when
1064 attaching to processes running in different mount namespaces from
1065 the debugger. This makes it possible to attach to processes in
1066 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1067 See "New remote packets" below.
1069 * The "tui reg" command now provides completion for all of the
1070 available register groups, including target specific groups.
1072 * The HISTSIZE environment variable is no longer read when determining
1073 the size of GDB's command history. GDB now instead reads the dedicated
1074 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1075 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1080 ** Memory ports can now be unbuffered.
1084 ** gdb.Objfile objects have a new attribute "username",
1085 which is the name of the objfile as specified by the user,
1086 without, for example, resolving symlinks.
1087 ** You can now write frame unwinders in Python.
1088 ** gdb.Type objects have a new method "optimized_out",
1089 returning optimized out gdb.Value instance of this type.
1090 ** gdb.Value objects have new methods "reference_value" and
1091 "const_value" which return a reference to the value and a
1092 "const" version of the value respectively.
1096 maint print symbol-cache
1097 Print the contents of the symbol cache.
1099 maint print symbol-cache-statistics
1100 Print statistics of symbol cache usage.
1102 maint flush-symbol-cache
1103 Flush the contents of the symbol cache.
1107 Start branch trace recording using Branch Trace Store (BTS) format.
1110 Evaluate expression by using the compiler and print result.
1114 Explicit commands for enabling and disabling tui mode.
1117 set mpx bound on i386 and amd64
1118 Support for bound table investigation on Intel MPX enabled applications.
1122 Start branch trace recording using Intel Processor Trace format.
1125 Print information about branch tracing internals.
1127 maint btrace packet-history
1128 Print the raw branch tracing data.
1130 maint btrace clear-packet-history
1131 Discard the stored raw branch tracing data.
1134 Discard all branch tracing data. It will be fetched and processed
1135 anew by the next "record" command.
1140 Renamed from "set debug dwarf2-die".
1141 show debug dwarf-die
1142 Renamed from "show debug dwarf2-die".
1144 set debug dwarf-read
1145 Renamed from "set debug dwarf2-read".
1146 show debug dwarf-read
1147 Renamed from "show debug dwarf2-read".
1149 maint set dwarf always-disassemble
1150 Renamed from "maint set dwarf2 always-disassemble".
1151 maint show dwarf always-disassemble
1152 Renamed from "maint show dwarf2 always-disassemble".
1154 maint set dwarf max-cache-age
1155 Renamed from "maint set dwarf2 max-cache-age".
1156 maint show dwarf max-cache-age
1157 Renamed from "maint show dwarf2 max-cache-age".
1159 set debug dwarf-line
1160 show debug dwarf-line
1161 Control display of debugging info regarding DWARF line processing.
1164 show max-completions
1165 Set the maximum number of candidates to be considered during
1166 completion. The default value is 200. This limit allows GDB
1167 to avoid generating large completion lists, the computation of
1168 which can cause the debugger to become temporarily unresponsive.
1170 set history remove-duplicates
1171 show history remove-duplicates
1172 Control the removal of duplicate history entries.
1174 maint set symbol-cache-size
1175 maint show symbol-cache-size
1176 Control the size of the symbol cache.
1178 set|show record btrace bts buffer-size
1179 Set and show the size of the ring buffer used for branch tracing in
1181 The obtained size may differ from the requested size. Use "info
1182 record" to see the obtained buffer size.
1184 set debug linux-namespaces
1185 show debug linux-namespaces
1186 Control display of debugging info regarding Linux namespaces.
1188 set|show record btrace pt buffer-size
1189 Set and show the size of the ring buffer used for branch tracing in
1190 Intel Processor Trace format.
1191 The obtained size may differ from the requested size. Use "info
1192 record" to see the obtained buffer size.
1194 maint set|show btrace pt skip-pad
1195 Set and show whether PAD packets are skipped when computing the
1198 * The command 'thread apply all' can now support new option '-ascending'
1199 to call its specified command for all threads in ascending order.
1201 * Python/Guile scripting
1203 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1204 special section named `.debug_gdb_scripts'.
1206 * New remote packets
1208 qXfer:btrace-conf:read
1209 Return the branch trace configuration for the current thread.
1211 Qbtrace-conf:bts:size
1212 Set the requested ring buffer size for branch tracing in BTS format.
1215 Enable Intel Procesor Trace-based branch tracing for the current
1216 process. The remote stub reports support for this packet to GDB's
1219 Qbtrace-conf:pt:size
1220 Set the requested ring buffer size for branch tracing in Intel Processor
1224 Indicates a memory breakpoint instruction was executed, irrespective
1225 of whether it was GDB that planted the breakpoint or the breakpoint
1226 is hardcoded in the program. This is required for correct non-stop
1230 Indicates the target stopped for a hardware breakpoint. This is
1231 required for correct non-stop mode operation.
1234 Return information about files on the remote system.
1236 qXfer:exec-file:read
1237 Return the full absolute name of the file that was executed to
1238 create a process running on the remote system.
1241 Select the filesystem on which vFile: operations with filename
1242 arguments will operate. This is required for GDB to be able to
1243 access files on remote targets where the remote stub does not
1244 share a common filesystem with the inferior(s).
1247 Indicates that a fork system call was executed.
1250 Indicates that a vfork system call was executed.
1252 vforkdone stop reason
1253 Indicates that a vfork child of the specified process has executed
1254 an exec or exit, allowing the vfork parent to resume execution.
1256 fork-events and vfork-events features in qSupported
1257 The qSupported packet allows GDB to request support for fork and
1258 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1259 and the qSupported response can contain the corresponding
1260 'stubfeatures'. Set and show commands can be used to display
1261 whether these features are enabled.
1263 * Extended-remote fork events
1265 ** GDB now has support for fork events on extended-remote Linux
1266 targets. For targets with Linux kernels 2.5.60 and later, this
1267 enables follow-fork-mode and detach-on-fork for both fork and
1268 vfork, as well as fork and vfork catchpoints.
1270 * The info record command now shows the recording format and the
1271 branch tracing configuration for the current thread when using
1272 the btrace record target.
1273 For the BTS format, it shows the ring buffer size.
1275 * GDB now has support for DTrace USDT (Userland Static Defined
1276 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1278 * GDB now supports access to vector registers on S/390 GNU/Linux
1281 * Removed command line options
1283 -xdb HP-UX XDB compatibility mode.
1285 * Removed targets and native configurations
1287 HP/PA running HP-UX hppa*-*-hpux*
1288 Itanium running HP-UX ia64-*-hpux*
1290 * New configure options
1293 This configure option allows the user to build GDB with support for
1294 Intel Processor Trace (default: auto). This requires libipt.
1296 --with-libipt-prefix=PATH
1297 Specify the path to the version of libipt that GDB should use.
1298 $PATH/include should contain the intel-pt.h header and
1299 $PATH/lib should contain the libipt.so library.
1301 *** Changes in GDB 7.9.1
1305 ** Xmethods can now specify a result type.
1307 *** Changes in GDB 7.9
1309 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1313 ** You can now access frame registers from Python scripts.
1314 ** New attribute 'producer' for gdb.Symtab objects.
1315 ** gdb.Objfile objects have a new attribute "progspace",
1316 which is the gdb.Progspace object of the containing program space.
1317 ** gdb.Objfile objects have a new attribute "owner".
1318 ** gdb.Objfile objects have a new attribute "build_id",
1319 which is the build ID generated when the file was built.
1320 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1321 ** A new event "gdb.clear_objfiles" has been added, triggered when
1322 selecting a new file to debug.
1323 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1324 ** New function gdb.lookup_objfile.
1326 New events which are triggered when GDB modifies the state of the
1329 ** gdb.events.inferior_call_pre: Function call is about to be made.
1330 ** gdb.events.inferior_call_post: Function call has just been made.
1331 ** gdb.events.memory_changed: A memory location has been altered.
1332 ** gdb.events.register_changed: A register has been altered.
1334 * New Python-based convenience functions:
1336 ** $_caller_is(name [, number_of_frames])
1337 ** $_caller_matches(regexp [, number_of_frames])
1338 ** $_any_caller_is(name [, number_of_frames])
1339 ** $_any_caller_matches(regexp [, number_of_frames])
1341 * GDB now supports the compilation and injection of source code into
1342 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1343 to compile the source code to object code, and if successful, inject
1344 and execute that code within the current context of the inferior.
1345 Currently the C language is supported. The commands used to
1346 interface with this new feature are:
1348 compile code [-raw|-r] [--] [source code]
1349 compile file [-raw|-r] filename
1353 demangle [-l language] [--] name
1354 Demangle "name" in the specified language, or the current language
1355 if elided. This command is renamed from the "maint demangle" command.
1356 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1357 as "maint demangler-warning".
1359 queue-signal signal-name-or-number
1360 Queue a signal to be delivered to the thread when it is resumed.
1362 add-auto-load-scripts-directory directory
1363 Add entries to the list of directories from which to load auto-loaded
1366 maint print user-registers
1367 List all currently available "user" registers.
1369 compile code [-r|-raw] [--] [source code]
1370 Compile, inject, and execute in the inferior the executable object
1371 code produced by compiling the provided source code.
1373 compile file [-r|-raw] filename
1374 Compile and inject into the inferior the executable object code
1375 produced by compiling the source code stored in the filename
1378 * On resume, GDB now always passes the signal the program had stopped
1379 for to the thread the signal was sent to, even if the user changed
1380 threads before resuming. Previously GDB would often (but not
1381 always) deliver the signal to the thread that happens to be current
1384 * Conversely, the "signal" command now consistently delivers the
1385 requested signal to the current thread. GDB now asks for
1386 confirmation if the program had stopped for a signal and the user
1387 switched threads meanwhile.
1389 * "breakpoint always-inserted" modes "off" and "auto" merged.
1391 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1392 won't remove breakpoints from the target until all threads stop,
1393 even in non-stop mode. The "auto" mode has been removed, and "off"
1394 is now the default mode.
1398 set debug symbol-lookup
1399 show debug symbol-lookup
1400 Control display of debugging info regarding symbol lookup.
1404 ** The -list-thread-groups command outputs an exit-code field for
1405 inferiors that have exited.
1409 MIPS SDE mips*-sde*-elf*
1413 Support for these obsolete configurations has been removed.
1415 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1416 SGI Irix-5.x mips-*-irix5*
1417 SGI Irix-6.x mips-*-irix6*
1418 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1419 VAX running Ultrix vax-*-ultrix*
1421 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1422 and "assf"), have been removed. Use the "sharedlibrary" command, or
1423 its alias "share", instead.
1425 *** Changes in GDB 7.8
1427 * New command line options
1430 This is an alias for the --data-directory option.
1432 * GDB supports printing and modifying of variable length automatic arrays
1433 as specified in ISO C99.
1435 * The ARM simulator now supports instruction level tracing
1436 with or without disassembly.
1440 GDB now has support for scripting using Guile. Whether this is
1441 available is determined at configure time.
1442 Guile version 2.0 or greater is required.
1443 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1445 * New commands (for set/show, see "New options" below)
1449 Invoke CODE by passing it to the Guile interpreter.
1453 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1455 info auto-load guile-scripts [regexp]
1456 Print the list of automatically loaded Guile scripts.
1458 * The source command is now capable of sourcing Guile scripts.
1459 This feature is dependent on the debugger being built with Guile support.
1463 set print symbol-loading (off|brief|full)
1464 show print symbol-loading
1465 Control whether to print informational messages when loading symbol
1466 information for a file. The default is "full", but when debugging
1467 programs with large numbers of shared libraries the amount of output
1468 becomes less useful.
1470 set guile print-stack (none|message|full)
1471 show guile print-stack
1472 Show a stack trace when an error is encountered in a Guile script.
1474 set auto-load guile-scripts (on|off)
1475 show auto-load guile-scripts
1476 Control auto-loading of Guile script files.
1478 maint ada set ignore-descriptive-types (on|off)
1479 maint ada show ignore-descriptive-types
1480 Control whether the debugger should ignore descriptive types in Ada
1481 programs. The default is not to ignore the descriptive types. See
1482 the user manual for more details on descriptive types and the intended
1483 usage of this option.
1485 set auto-connect-native-target
1487 Control whether GDB is allowed to automatically connect to the
1488 native target for the run, attach, etc. commands when not connected
1489 to any target yet. See also "target native" below.
1491 set record btrace replay-memory-access (read-only|read-write)
1492 show record btrace replay-memory-access
1493 Control what memory accesses are allowed during replay.
1495 maint set target-async (on|off)
1496 maint show target-async
1497 This controls whether GDB targets operate in synchronous or
1498 asynchronous mode. Normally the default is asynchronous, if it is
1499 available; but this can be changed to more easily debug problems
1500 occurring only in synchronous mode.
1502 set mi-async (on|off)
1504 Control whether MI asynchronous mode is preferred. This supersedes
1505 "set target-async" of previous GDB versions.
1507 * "set target-async" is deprecated as a CLI option and is now an alias
1508 for "set mi-async" (only puts MI into async mode).
1510 * Background execution commands (e.g., "c&", "s&", etc.) are now
1511 possible ``out of the box'' if the target supports them. Previously
1512 the user would need to explicitly enable the possibility with the
1513 "set target-async on" command.
1515 * New features in the GDB remote stub, GDBserver
1517 ** New option --debug-format=option1[,option2,...] allows one to add
1518 additional text to each output. At present only timestamps
1519 are supported: --debug-format=timestamps.
1520 Timestamps can also be turned on with the
1521 "monitor set debug-format timestamps" command from GDB.
1523 * The 'record instruction-history' command now starts counting instructions
1524 at one. This also affects the instruction ranges reported by the
1525 'record function-call-history' command when given the /i modifier.
1527 * The command 'record function-call-history' supports a new modifier '/c' to
1528 indent the function names based on their call stack depth.
1529 The fields for the '/i' and '/l' modifier have been reordered.
1530 The source line range is now prefixed with 'at'.
1531 The instruction range is now prefixed with 'inst'.
1532 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1533 "record instruction-history" and "list" commands.
1535 * The ranges given as arguments to the 'record function-call-history' and
1536 'record instruction-history' commands are now inclusive.
1538 * The btrace record target now supports the 'record goto' command.
1539 For locations inside the execution trace, the back trace is computed
1540 based on the information stored in the execution trace.
1542 * The btrace record target supports limited reverse execution and replay.
1543 The target does not record data and therefore does not allow reading
1544 memory or registers.
1546 * The "catch syscall" command now works on s390*-linux* targets.
1548 * The "compare-sections" command is no longer specific to target
1549 remote. It now works with all targets.
1551 * All native targets are now consistently called "native".
1552 Consequently, the "target child", "target GNU", "target djgpp",
1553 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1554 commands have been replaced with "target native". The QNX/NTO port
1555 leaves the "procfs" target in place and adds a "native" target for
1556 consistency with other ports. The impact on users should be minimal
1557 as these commands previously either throwed an error, or were
1558 no-ops. The target's name is visible in the output of the following
1559 commands: "help target", "info target", "info files", "maint print
1562 * The "target native" command now connects to the native target. This
1563 can be used to launch native programs even when "set
1564 auto-connect-native-target" is set to off.
1566 * GDB now supports access to Intel MPX registers on GNU/Linux.
1568 * Support for Intel AVX-512 registers on GNU/Linux.
1569 Support displaying and modifying Intel AVX-512 registers
1570 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1572 * New remote packets
1574 qXfer:btrace:read's annex
1575 The qXfer:btrace:read packet supports a new annex 'delta' to read
1576 branch trace incrementally.
1580 ** Valid Python operations on gdb.Value objects representing
1581 structs/classes invoke the corresponding overloaded operators if
1583 ** New `Xmethods' feature in the Python API. Xmethods are
1584 additional methods or replacements for existing methods of a C++
1585 class. This feature is useful for those cases where a method
1586 defined in C++ source code could be inlined or optimized out by
1587 the compiler, making it unavailable to GDB.
1590 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1592 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1593 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1594 its alias "share", instead.
1596 * The commands "set remotebaud" and "show remotebaud" are no longer
1597 supported. Use "set serial baud" and "show serial baud" (respectively)
1602 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1603 target-async". The latter is left as a deprecated alias of the
1604 former for backward compatibility. If the target supports it,
1605 CLI background execution commands are now always possible by
1606 default, independently of whether the frontend stated a
1607 preference for asynchronous execution with "-gdb-set mi-async".
1608 Previously "-gdb-set target-async off" affected both MI execution
1609 commands and CLI execution commands.
1611 *** Changes in GDB 7.7
1613 * Improved support for process record-replay and reverse debugging on
1614 arm*-linux* targets. Support for thumb32 and syscall instruction
1615 recording has been added.
1617 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1619 * GDB now supports Fission DWP file format version 2.
1620 http://gcc.gnu.org/wiki/DebugFission
1622 * New convenience function "$_isvoid", to check whether an expression
1623 is void. A void expression is an expression where the type of the
1624 result is "void". For example, some convenience variables may be
1625 "void" when evaluated (e.g., "$_exitcode" before the execution of
1626 the program being debugged; or an undefined convenience variable).
1627 Another example, when calling a function whose return type is
1630 * The "maintenance print objfiles" command now takes an optional regexp.
1632 * The "catch syscall" command now works on arm*-linux* targets.
1634 * GDB now consistently shows "<not saved>" when printing values of
1635 registers the debug info indicates have not been saved in the frame
1636 and there's nowhere to retrieve them from
1637 (callee-saved/call-clobbered registers):
1642 (gdb) info registers rax
1645 Before, the former would print "<optimized out>", and the latter
1646 "*value not available*".
1648 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1653 ** Frame filters and frame decorators have been added.
1654 ** Temporary breakpoints are now supported.
1655 ** Line tables representation has been added.
1656 ** New attribute 'parent_type' for gdb.Field objects.
1657 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1658 ** New attribute 'name' for gdb.Type objects.
1662 Nios II ELF nios2*-*-elf
1663 Nios II GNU/Linux nios2*-*-linux
1664 Texas Instruments MSP430 msp430*-*-elf
1666 * Removed native configurations
1668 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1669 been removed. ELF variants of these configurations are kept supported.
1671 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1672 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1673 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1674 i[34567]86-*-openbsd3.[0-3]
1675 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1676 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1677 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1681 Like "catch throw", but catches a re-thrown exception.
1682 maint check-psymtabs
1683 Renamed from old "maint check-symtabs".
1685 Perform consistency checks on symtabs.
1686 maint expand-symtabs
1687 Expand symtabs matching an optional regexp.
1690 Display the details of GDB configure-time options.
1692 maint set|show per-command
1693 maint set|show per-command space
1694 maint set|show per-command time
1695 maint set|show per-command symtab
1696 Enable display of per-command gdb resource usage.
1698 remove-symbol-file FILENAME
1699 remove-symbol-file -a ADDRESS
1700 Remove a symbol file added via add-symbol-file. The file to remove
1701 can be identified by its filename or by an address that lies within
1702 the boundaries of this symbol file in memory.
1705 info exceptions REGEXP
1706 Display the list of Ada exceptions defined in the program being
1707 debugged. If provided, only the exceptions whose names match REGEXP
1712 set debug symfile off|on
1714 Control display of debugging info regarding reading symbol files and
1715 symbol tables within those files
1717 set print raw frame-arguments
1718 show print raw frame-arguments
1719 Set/show whether to print frame arguments in raw mode,
1720 disregarding any defined pretty-printers.
1722 set remote trace-status-packet
1723 show remote trace-status-packet
1724 Set/show the use of remote protocol qTStatus packet.
1728 Control display of debugging messages related to Nios II targets.
1732 Control whether target-assisted range stepping is enabled.
1734 set startup-with-shell
1735 show startup-with-shell
1736 Specifies whether Unix child processes are started via a shell or
1741 Use the target memory cache for accesses to the code segment. This
1742 improves performance of remote debugging (particularly disassembly).
1744 * You can now use a literal value 'unlimited' for options that
1745 interpret 0 or -1 as meaning "unlimited". E.g., "set
1746 trace-buffer-size unlimited" is now an alias for "set
1747 trace-buffer-size -1" and "set height unlimited" is now an alias for
1750 * The "set debug symtab-create" debugging option of GDB has been changed to
1751 accept a verbosity level. 0 means "off", 1 provides basic debugging
1752 output, and values of 2 or greater provides more verbose output.
1754 * New command-line options
1756 Display the details of GDB configure-time options.
1758 * The command 'tsave' can now support new option '-ctf' to save trace
1759 buffer in Common Trace Format.
1761 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1764 * GDB now implements the the C++ 'typeid' operator.
1766 * The new convenience variable $_exception holds the exception being
1767 thrown or caught at an exception-related catchpoint.
1769 * The exception-related catchpoints, like "catch throw", now accept a
1770 regular expression which can be used to filter exceptions by type.
1772 * The new convenience variable $_exitsignal is automatically set to
1773 the terminating signal number when the program being debugged dies
1774 due to an uncaught signal.
1778 ** All MI commands now accept an optional "--language" option.
1779 Support for this feature can be verified by using the "-list-features"
1780 command, which should contain "language-option".
1782 ** The new command -info-gdb-mi-command allows the user to determine
1783 whether a GDB/MI command is supported or not.
1785 ** The "^error" result record returned when trying to execute an undefined
1786 GDB/MI command now provides a variable named "code" whose content is the
1787 "undefined-command" error code. Support for this feature can be verified
1788 by using the "-list-features" command, which should contain
1789 "undefined-command-error-code".
1791 ** The -trace-save MI command can optionally save trace buffer in Common
1794 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1796 ** The command -data-list-register-values now accepts an optional
1797 "--skip-unavailable" option. When used, only the available registers
1800 ** The new command -trace-frame-collected dumps collected variables,
1801 computed expressions, tvars, memory and registers in a traceframe.
1803 ** The commands -stack-list-locals, -stack-list-arguments and
1804 -stack-list-variables now accept an option "--skip-unavailable".
1805 When used, only the available locals or arguments are displayed.
1807 ** The -exec-run command now accepts an optional "--start" option.
1808 When used, the command follows the same semantics as the "start"
1809 command, stopping the program's execution at the start of its
1810 main subprogram. Support for this feature can be verified using
1811 the "-list-features" command, which should contain
1812 "exec-run-start-option".
1814 ** The new commands -catch-assert and -catch-exceptions insert
1815 catchpoints stopping the program when Ada exceptions are raised.
1817 ** The new command -info-ada-exceptions provides the equivalent of
1818 the new "info exceptions" command.
1820 * New system-wide configuration scripts
1821 A GDB installation now provides scripts suitable for use as system-wide
1822 configuration scripts for the following systems:
1826 * GDB now supports target-assigned range stepping with remote targets.
1827 This improves the performance of stepping source lines by reducing
1828 the number of control packets from/to GDB. See "New remote packets"
1831 * GDB now understands the element 'tvar' in the XML traceframe info.
1832 It has the id of the collected trace state variables.
1834 * On S/390 targets that provide the transactional-execution feature,
1835 the program interruption transaction diagnostic block (TDB) is now
1836 represented as a number of additional "registers" in GDB.
1838 * New remote packets
1842 The vCont packet supports a new 'r' action, that tells the remote
1843 stub to step through an address range itself, without GDB
1844 involvemement at each single-step.
1846 qXfer:libraries-svr4:read's annex
1847 The previously unused annex of the qXfer:libraries-svr4:read packet
1848 is now used to support passing an argument list. The remote stub
1849 reports support for this argument list to GDB's qSupported query.
1850 The defined arguments are "start" and "prev", used to reduce work
1851 necessary for library list updating, resulting in significant
1854 * New features in the GDB remote stub, GDBserver
1856 ** GDBserver now supports target-assisted range stepping. Currently
1857 enabled on x86/x86_64 GNU/Linux targets.
1859 ** GDBserver now adds element 'tvar' in the XML in the reply to
1860 'qXfer:traceframe-info:read'. It has the id of the collected
1861 trace state variables.
1863 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1866 * New 'z' formatter for printing and examining memory, this displays the
1867 value as hexadecimal zero padded on the left to the size of the type.
1869 * GDB can now use Windows x64 unwinding data.
1871 * The "set remotebaud" command has been replaced by "set serial baud".
1872 Similarly, "show remotebaud" has been replaced by "show serial baud".
1873 The "set remotebaud" and "show remotebaud" commands are still available
1874 to provide backward compatibility with older versions of GDB.
1876 *** Changes in GDB 7.6
1878 * Target record has been renamed to record-full.
1879 Record/replay is now enabled with the "record full" command.
1880 This also affects settings that are associated with full record/replay
1881 that have been moved from "set/show record" to "set/show record full":
1883 set|show record full insn-number-max
1884 set|show record full stop-at-limit
1885 set|show record full memory-query
1887 * A new record target "record-btrace" has been added. The new target
1888 uses hardware support to record the control-flow of a process. It
1889 does not support replaying the execution, but it implements the
1890 below new commands for investigating the recorded execution log.
1891 This new recording method can be enabled using:
1895 The "record-btrace" target is only available on Intel Atom processors
1896 and requires a Linux kernel 2.6.32 or later.
1898 * Two new commands have been added for record/replay to give information
1899 about the recorded execution without having to replay the execution.
1900 The commands are only supported by "record btrace".
1902 record instruction-history prints the execution history at
1903 instruction granularity
1905 record function-call-history prints the execution history at
1906 function granularity
1908 * New native configurations
1910 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1911 FreeBSD/powerpc powerpc*-*-freebsd
1912 x86_64/Cygwin x86_64-*-cygwin*
1913 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1917 ARM AArch64 aarch64*-*-elf
1918 ARM AArch64 GNU/Linux aarch64*-*-linux
1919 Lynx 178 PowerPC powerpc-*-lynx*178
1920 x86_64/Cygwin x86_64-*-cygwin*
1921 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1923 * If the configured location of system.gdbinit file (as given by the
1924 --with-system-gdbinit option at configure time) is in the
1925 data-directory (as specified by --with-gdb-datadir at configure
1926 time) or in one of its subdirectories, then GDB will look for the
1927 system-wide init file in the directory specified by the
1928 --data-directory command-line option.
1930 * New command line options:
1932 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1933 other initialization files, unlike -nx which disables all of them.
1935 * Removed command line options
1937 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1940 * The 'ptype' and 'whatis' commands now accept an argument to control
1943 * 'info proc' now works on some core files.
1947 ** Vectors can be created with gdb.Type.vector.
1949 ** Python's atexit.register now works in GDB.
1951 ** Types can be pretty-printed via a Python API.
1953 ** Python 3 is now supported (in addition to Python 2.4 or later)
1955 ** New class gdb.Architecture exposes GDB's internal representation
1956 of architecture in the Python API.
1958 ** New method Frame.architecture returns the gdb.Architecture object
1959 corresponding to the frame's architecture.
1961 * New Python-based convenience functions:
1963 ** $_memeq(buf1, buf2, length)
1964 ** $_streq(str1, str2)
1966 ** $_regex(str, regex)
1968 * The 'cd' command now defaults to using '~' (the home directory) if not
1971 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1972 default for GCC since November 2000.
1974 * The command 'forward-search' can now be abbreviated as 'fo'.
1976 * The command 'info tracepoints' can now display 'installed on target'
1977 or 'not installed on target' for each non-pending location of tracepoint.
1979 * New configure options
1981 --enable-libmcheck/--disable-libmcheck
1982 By default, development versions are built with -lmcheck on hosts
1983 that support it, in order to help track memory corruption issues.
1984 Release versions, on the other hand, are built without -lmcheck
1985 by default. The --enable-libmcheck/--disable-libmcheck configure
1986 options allow the user to override that default.
1987 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1988 This configure option allows the user to build GDB with
1989 libbabeltrace using which GDB can read Common Trace Format data.
1991 * New commands (for set/show, see "New options" below)
1994 Catch signals. This is similar to "handle", but allows commands and
1995 conditions to be attached.
1998 List the BFDs known to GDB.
2000 python-interactive [command]
2002 Start a Python interactive prompt, or evaluate the optional command
2003 and print the result of expressions.
2006 "py" is a new alias for "python".
2008 enable type-printer [name]...
2009 disable type-printer [name]...
2010 Enable or disable type printers.
2014 ** For the Renesas Super-H architecture, the "regs" command has been removed
2015 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2020 set print type methods (on|off)
2021 show print type methods
2022 Control whether method declarations are displayed by "ptype".
2023 The default is to show them.
2025 set print type typedefs (on|off)
2026 show print type typedefs
2027 Control whether typedef definitions are displayed by "ptype".
2028 The default is to show them.
2030 set filename-display basename|relative|absolute
2031 show filename-display
2032 Control the way in which filenames is displayed.
2033 The default is "relative", which preserves previous behavior.
2035 set trace-buffer-size
2036 show trace-buffer-size
2037 Request target to change the size of trace buffer.
2039 set remote trace-buffer-size-packet auto|on|off
2040 show remote trace-buffer-size-packet
2041 Control the use of the remote protocol `QTBuffer:size' packet.
2045 Control display of debugging messages related to ARM AArch64.
2048 set debug coff-pe-read
2049 show debug coff-pe-read
2050 Control display of debugging messages related to reading of COFF/PE
2055 Control display of debugging messages related to Mach-O symbols
2058 set debug notification
2059 show debug notification
2060 Control display of debugging info for async remote notification.
2064 ** Command parameter changes are now notified using new async record
2065 "=cmd-param-changed".
2066 ** Trace frame changes caused by command "tfind" are now notified using
2067 new async record "=traceframe-changed".
2068 ** The creation, deletion and modification of trace state variables
2069 are now notified using new async records "=tsv-created",
2070 "=tsv-deleted" and "=tsv-modified".
2071 ** The start and stop of process record are now notified using new
2072 async record "=record-started" and "=record-stopped".
2073 ** Memory changes are now notified using new async record
2075 ** The data-disassemble command response will include a "fullname" field
2076 containing the absolute file name when source has been requested.
2077 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2078 command, to allow pattern filling of memory areas.
2079 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2080 library load/unload events.
2081 ** The response to breakpoint commands and breakpoint async records
2082 includes an "installed" field containing a boolean state about each
2083 non-pending tracepoint location is whether installed on target or not.
2084 ** Output of the "-trace-status" command includes a "trace-file" field
2085 containing the name of the trace file being examined. This field is
2086 optional, and only present when examining a trace file.
2087 ** The "fullname" field is now always present along with the "file" field,
2088 even if the file cannot be found by GDB.
2090 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2091 You must have the LZMA library available when configuring GDB for this
2092 feature to be enabled. For more information, see:
2093 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2095 * New remote packets
2098 Set the size of trace buffer. The remote stub reports support for this
2099 packet to gdb's qSupported query.
2102 Enable Branch Trace Store (BTS)-based branch tracing for the current
2103 thread. The remote stub reports support for this packet to gdb's
2107 Disable branch tracing for the current thread. The remote stub reports
2108 support for this packet to gdb's qSupported query.
2111 Read the traced branches for the current thread. The remote stub
2112 reports support for this packet to gdb's qSupported query.
2114 *** Changes in GDB 7.5
2116 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2117 for more x32 ABI info.
2119 * GDB now supports access to MIPS DSP registers on Linux targets.
2121 * GDB now supports debugging microMIPS binaries.
2123 * The "info os" command on GNU/Linux can now display information on
2124 several new classes of objects managed by the operating system:
2125 "info os procgroups" lists process groups
2126 "info os files" lists file descriptors
2127 "info os sockets" lists internet-domain sockets
2128 "info os shm" lists shared-memory regions
2129 "info os semaphores" lists semaphores
2130 "info os msg" lists message queues
2131 "info os modules" lists loaded kernel modules
2133 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2134 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2135 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2136 options and inspect the probe arguments using the new $_probe_arg family
2137 of convenience variables. You can obtain more information about SystemTap
2138 in <http://sourceware.org/systemtap/>.
2140 * GDB now supports reversible debugging on ARM, it allows you to
2141 debug basic ARM and THUMB instructions, and provides
2142 record/replay support.
2144 * The option "symbol-reloading" has been deleted as it is no longer used.
2148 ** GDB commands implemented in Python can now be put in command class
2151 ** The "maint set python print-stack on|off" is now deleted.
2153 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2154 apply "flag enum"-style pretty-printing to any enum.
2156 ** gdb.lookup_symbol can now work when there is no current frame.
2158 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2159 the source at which the symbol was defined.
2161 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2162 method 'value'. The former indicates whether the symbol needs a
2163 frame in order to compute its value, and the latter computes the
2166 ** A new method 'referenced_value' on gdb.Value objects which can
2167 dereference pointer as well as C++ reference values.
2169 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2170 which return the global and static blocks (as gdb.Block objects),
2171 of the underlying symbol table, respectively.
2173 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2174 object associated with a PC value.
2176 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2177 of the address range occupied by code for the current source line.
2179 * Go language support.
2180 GDB now supports debugging programs written in the Go programming
2183 * GDBserver now supports stdio connections.
2184 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2186 * The binary "gdbtui" can no longer be built or installed.
2187 Use "gdb -tui" instead.
2189 * GDB will now print "flag" enums specially. A flag enum is one where
2190 all the enumerator values have no bits in common when pairwise
2191 "and"ed. When printing a value whose type is a flag enum, GDB will
2192 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2193 (gdb) print (enum E) 3
2196 * The filename part of a linespec will now match trailing components
2197 of a source file name. For example, "break gcc/expr.c:1000" will
2198 now set a breakpoint in build/gcc/expr.c, but not
2199 build/libcpp/expr.c.
2201 * The "info proc" and "generate-core-file" commands will now also
2202 work on remote targets connected to GDBserver on Linux.
2204 * The command "info catch" has been removed. It has been disabled
2205 since December 2007.
2207 * The "catch exception" and "catch assert" commands now accept
2208 a condition at the end of the command, much like the "break"
2209 command does. For instance:
2211 (gdb) catch exception Constraint_Error if Barrier = True
2213 Previously, it was possible to add a condition to such catchpoints,
2214 but it had to be done as a second step, after the catchpoint had been
2215 created, using the "condition" command.
2217 * The "info static-tracepoint-marker" command will now also work on
2218 native Linux targets with in-process agent.
2220 * GDB can now set breakpoints on inlined functions.
2222 * The .gdb_index section has been updated to include symbols for
2223 inlined functions. GDB will ignore older .gdb_index sections by
2224 default, which could cause symbol files to be loaded more slowly
2225 until their .gdb_index sections can be recreated. The new command
2226 "set use-deprecated-index-sections on" will cause GDB to use any older
2227 .gdb_index sections it finds. This will restore performance, but the
2228 ability to set breakpoints on inlined functions will be lost in symbol
2229 files with older .gdb_index sections.
2231 The .gdb_index section has also been updated to record more information
2232 about each symbol. This speeds up the "info variables", "info functions"
2233 and "info types" commands when used with programs having the .gdb_index
2234 section, as well as speeding up debugging with shared libraries using
2235 the .gdb_index section.
2237 * Ada support for GDB/MI Variable Objects has been added.
2239 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2244 ** New command -info-os is the MI equivalent of "info os".
2246 ** Output logs ("set logging" and related) now include MI output.
2250 ** "set use-deprecated-index-sections on|off"
2251 "show use-deprecated-index-sections on|off"
2252 Controls the use of deprecated .gdb_index sections.
2254 ** "catch load" and "catch unload" can be used to stop when a shared
2255 library is loaded or unloaded, respectively.
2257 ** "enable count" can be used to auto-disable a breakpoint after
2260 ** "info vtbl" can be used to show the virtual method tables for
2261 C++ and Java objects.
2263 ** "explore" and its sub commands "explore value" and "explore type"
2264 can be used to recursively explore values and types of
2265 expressions. These commands are available only if GDB is
2266 configured with '--with-python'.
2268 ** "info auto-load" shows status of all kinds of auto-loaded files,
2269 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2270 sequences of commands files, "info auto-load python-scripts"
2271 shows status of auto-loading Python script files,
2272 "info auto-load local-gdbinit" shows status of loading init file
2273 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2274 status of inferior specific thread debugging shared library loading.
2276 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2277 and "show auto-load-scripts" commands have been deprecated, use their
2278 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2279 and "show auto-load python-scripts" counterparts instead.
2281 ** "dprintf location,format,args..." creates a dynamic printf, which
2282 is basically a breakpoint that does a printf and immediately
2283 resumes your program's execution, so it is like a printf that you
2284 can insert dynamically at runtime instead of at compiletime.
2286 ** "set print symbol"
2288 Controls whether GDB attempts to display the symbol, if any,
2289 corresponding to addresses it prints. This defaults to "on", but
2290 you can set it to "off" to restore GDB's previous behavior.
2292 * Deprecated commands
2294 ** For the Renesas Super-H architecture, the "regs" command has been
2295 deprecated, and "info all-registers" should be used instead.
2299 Renesas RL78 rl78-*-elf
2300 HP OpenVMS ia64 ia64-hp-openvms*
2302 * GDBserver supports evaluation of breakpoint conditions. When
2303 support is advertised by GDBserver, GDB may be told to send the
2304 breakpoint conditions in bytecode form to GDBserver. GDBserver
2305 will only report the breakpoint trigger to GDB when its condition
2310 set mips compression
2311 show mips compression
2312 Select the compressed ISA encoding used in functions that have no symbol
2313 information available. The encoding can be set to either of:
2316 and is updated automatically from ELF file flags if available.
2318 set breakpoint condition-evaluation
2319 show breakpoint condition-evaluation
2320 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2321 GDBserver ("target"). Default option "auto" chooses the most efficient
2323 This option can improve debugger efficiency depending on the speed of the
2327 Disable auto-loading globally.
2330 Show auto-loading setting of all kinds of auto-loaded files.
2332 set auto-load gdb-scripts on|off
2333 show auto-load gdb-scripts
2334 Control auto-loading of GDB canned sequences of commands files.
2336 set auto-load python-scripts on|off
2337 show auto-load python-scripts
2338 Control auto-loading of Python script files.
2340 set auto-load local-gdbinit on|off
2341 show auto-load local-gdbinit
2342 Control loading of init file (.gdbinit) from current directory.
2344 set auto-load libthread-db on|off
2345 show auto-load libthread-db
2346 Control auto-loading of inferior specific thread debugging shared library.
2348 set auto-load scripts-directory <dir1>[:<dir2>...]
2349 show auto-load scripts-directory
2350 Set a list of directories from which to load auto-loaded scripts.
2351 Automatically loaded Python scripts and GDB scripts are located in one
2352 of the directories listed by this option.
2353 The delimiter (':' above) may differ according to the host platform.
2355 set auto-load safe-path <dir1>[:<dir2>...]
2356 show auto-load safe-path
2357 Set a list of directories from which it is safe to auto-load files.
2358 The delimiter (':' above) may differ according to the host platform.
2360 set debug auto-load on|off
2361 show debug auto-load
2362 Control display of debugging info for auto-loading the files above.
2364 set dprintf-style gdb|call|agent
2366 Control the way in which a dynamic printf is performed; "gdb"
2367 requests a GDB printf command, while "call" causes dprintf to call a
2368 function in the inferior. "agent" requests that the target agent
2369 (such as GDBserver) do the printing.
2371 set dprintf-function <expr>
2372 show dprintf-function
2373 set dprintf-channel <expr>
2374 show dprintf-channel
2375 Set the function and optional first argument to the call when using
2376 the "call" style of dynamic printf.
2378 set disconnected-dprintf on|off
2379 show disconnected-dprintf
2380 Control whether agent-style dynamic printfs continue to be in effect
2381 after GDB disconnects.
2383 * New configure options
2385 --with-auto-load-dir
2386 Configure default value for the 'set auto-load scripts-directory'
2387 setting above. It defaults to '$debugdir:$datadir/auto-load',
2388 $debugdir representing global debugging info directories (available
2389 via 'show debug-file-directory') and $datadir representing GDB's data
2390 directory (available via 'show data-directory').
2392 --with-auto-load-safe-path
2393 Configure default value for the 'set auto-load safe-path' setting
2394 above. It defaults to the --with-auto-load-dir setting.
2396 --without-auto-load-safe-path
2397 Set 'set auto-load safe-path' to '/', effectively disabling this
2400 * New remote packets
2402 z0/z1 conditional breakpoints extension
2404 The z0/z1 breakpoint insertion packets have been extended to carry
2405 a list of conditional expressions over to the remote stub depending on the
2406 condition evaluation mode. The use of this extension can be controlled
2407 via the "set remote conditional-breakpoints-packet" command.
2411 Specify the signals which the remote stub may pass to the debugged
2412 program without GDB involvement.
2414 * New command line options
2416 --init-command=FILE, -ix Like --command, -x but execute it
2417 before loading inferior.
2418 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2419 execute it before loading inferior.
2421 *** Changes in GDB 7.4
2423 * GDB now handles ambiguous linespecs more consistently; the existing
2424 FILE:LINE support has been expanded to other types of linespecs. A
2425 breakpoint will now be set on all matching locations in all
2426 inferiors, and locations will be added or removed according to
2429 * GDB now allows you to skip uninteresting functions and files when
2430 stepping with the "skip function" and "skip file" commands.
2432 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2433 and "show remote hardware-watchpoint-length-limit". These allows to
2434 set or show the maximum length limit (in bytes) of a remote
2435 target hardware watchpoint.
2437 This allows e.g. to use "unlimited" hardware watchpoints with the
2438 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2439 watchpoints are slower than real hardware watchpoints but are
2440 significantly faster than gdb software watchpoints.
2444 ** The register_pretty_printer function in module gdb.printing now takes
2445 an optional `replace' argument. If True, the new printer replaces any
2448 ** The "maint set python print-stack on|off" command has been
2449 deprecated and will be deleted in GDB 7.5.
2450 A new command: "set python print-stack none|full|message" has
2451 replaced it. Additionally, the default for "print-stack" is
2452 now "message", which just prints the error message without
2455 ** A prompt substitution hook (prompt_hook) is now available to the
2458 ** A new Python module, gdb.prompt has been added to the GDB Python
2459 modules library. This module provides functionality for
2460 escape sequences in prompts (used by set/show
2461 extended-prompt). These escape sequences are replaced by their
2462 corresponding value.
2464 ** Python commands and convenience-functions located in
2465 'data-directory'/python/gdb/command and
2466 'data-directory'/python/gdb/function are now automatically loaded
2469 ** Blocks now provide four new attributes. global_block and
2470 static_block will return the global and static blocks
2471 respectively. is_static and is_global are boolean attributes
2472 that indicate if the block is one of those two types.
2474 ** Symbols now provide the "type" attribute, the type of the symbol.
2476 ** The "gdb.breakpoint" function has been deprecated in favor of
2479 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2480 of a function. This class is based on the "finish" command
2481 available in the CLI.
2483 ** Type objects for struct and union types now allow access to
2484 the fields using standard Python dictionary (mapping) methods.
2485 For example, "some_type['myfield']" now works, as does
2486 "some_type.items()".
2488 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2491 ** A new function, "deep_items" has been added to the gdb.types
2492 module in the GDB Python modules library. This function returns
2493 an iterator over the fields of a struct or union type. Unlike
2494 the standard Python "iteritems" method, it will recursively traverse
2495 any anonymous fields.
2499 ** "*stopped" events can report several new "reason"s, such as
2502 ** Breakpoint changes are now notified using new async records, like
2503 "=breakpoint-modified".
2505 ** New command -ada-task-info.
2507 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2508 $sdir specifies the default system locations of shared libraries.
2509 $pdir specifies the directory where the libpthread used by the application
2512 GDB no longer looks in $sdir and $pdir after it has searched the directories
2513 mentioned in libthread-db-search-path. If you want to search those
2514 directories, they must be specified in libthread-db-search-path.
2515 The default value of libthread-db-search-path on GNU/Linux and Solaris
2516 systems is now "$sdir:$pdir".
2518 $pdir is not supported by gdbserver, it is currently ignored.
2519 $sdir is supported by gdbserver.
2521 * New configure option --with-iconv-bin.
2522 When using the internationalization support like the one in the GNU C
2523 library, GDB will invoke the "iconv" program to get a list of supported
2524 character sets. If this program lives in a non-standard location, one can
2525 use this option to specify where to find it.
2527 * When natively debugging programs on PowerPC BookE processors running
2528 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2529 watchpoints, which specify a mask in addition to an address to watch.
2530 The mask specifies that some bits of an address (the bits which are
2531 reset in the mask) should be ignored when matching the address accessed
2532 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2533 section in the user manual for more details.
2535 * The new option --once causes GDBserver to stop listening for connections once
2536 the first connection is made. The listening port used by GDBserver will
2537 become available after that.
2539 * New commands "info macros" and "alias" have been added.
2541 * New function parameters suffix @entry specifies value of function parameter
2542 at the time the function got called. Entry values are available only since
2548 "!" is now an alias of the "shell" command.
2549 Note that no space is needed between "!" and SHELL COMMAND.
2553 watch EXPRESSION mask MASK_VALUE
2554 The watch command now supports the mask argument which allows creation
2555 of masked watchpoints, if the current architecture supports this feature.
2557 info auto-load-scripts [REGEXP]
2558 This command was formerly named "maintenance print section-scripts".
2559 It is now generally useful and is no longer a maintenance-only command.
2561 info macro [-all] [--] MACRO
2562 The info macro command has new options `-all' and `--'. The first for
2563 printing all definitions of a macro. The second for explicitly specifying
2564 the end of arguments and the beginning of the macro name in case the macro
2565 name starts with a hyphen.
2567 collect[/s] EXPRESSIONS
2568 The tracepoint collect command now takes an optional modifier "/s"
2569 that directs it to dereference pointer-to-character types and
2570 collect the bytes of memory up to a zero byte. The behavior is
2571 similar to what you see when you use the regular print command on a
2572 string. An optional integer following the "/s" sets a bound on the
2573 number of bytes that will be collected.
2576 The trace start command now interprets any supplied arguments as a
2577 note to be recorded with the trace run, with an effect similar to
2578 setting the variable trace-notes.
2581 The trace stop command now interprets any arguments as a note to be
2582 mentioned along with the tstatus report that the trace was stopped
2583 with a command. The effect is similar to setting the variable
2586 * Tracepoints can now be enabled and disabled at any time after a trace
2587 experiment has been started using the standard "enable" and "disable"
2588 commands. It is now possible to start a trace experiment with no enabled
2589 tracepoints; GDB will display a warning, but will allow the experiment to
2590 begin, assuming that tracepoints will be enabled as needed while the trace
2593 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2594 locations with 4-byte instructions, when they were previously
2595 limited to locations with instructions of 5 bytes or longer.
2599 set debug dwarf2-read
2600 show debug dwarf2-read
2601 Turns on or off display of debugging messages related to reading
2602 DWARF debug info. The default is off.
2604 set debug symtab-create
2605 show debug symtab-create
2606 Turns on or off display of debugging messages related to symbol table
2607 creation. The default is off.
2610 show extended-prompt
2611 Set the GDB prompt, and allow escape sequences to be inserted to
2612 display miscellaneous information (see 'help set extended-prompt'
2613 for the list of sequences). This prompt (and any information
2614 accessed through the escape sequences) is updated every time the
2615 prompt is displayed.
2617 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2618 show print entry-values
2619 Set printing of frame argument values at function entry. In some cases
2620 GDB can determine the value of function argument which was passed by the
2621 function caller, even if the value was modified inside the called function.
2623 set debug entry-values
2624 show debug entry-values
2625 Control display of debugging info for determining frame argument values at
2626 function entry and virtual tail call frames.
2628 set basenames-may-differ
2629 show basenames-may-differ
2630 Set whether a source file may have multiple base names.
2631 (A "base name" is the name of a file with the directory part removed.
2632 Example: The base name of "/home/user/hello.c" is "hello.c".)
2633 If set, GDB will canonicalize file names (e.g., expand symlinks)
2634 before comparing them. Canonicalization is an expensive operation,
2635 but it allows the same file be known by more than one base name.
2636 If not set (the default), all source files are assumed to have just
2637 one base name, and gdb will do file name comparisons more efficiently.
2643 Set a user name and notes for the current and any future trace runs.
2644 This is useful for long-running and/or disconnected traces, to
2645 inform others (or yourself) as to who is running the trace, supply
2646 contact information, or otherwise explain what is going on.
2648 set trace-stop-notes
2649 show trace-stop-notes
2650 Set a note attached to the trace run, that is displayed when the
2651 trace has been stopped by a tstop command. This is useful for
2652 instance as an explanation, if you are stopping a trace run that was
2653 started by someone else.
2655 * New remote packets
2659 Dynamically enable a tracepoint in a started trace experiment.
2663 Dynamically disable a tracepoint in a started trace experiment.
2667 Set the user and notes of the trace run.
2671 Query the current status of a tracepoint.
2675 Query the minimum length of instruction at which a fast tracepoint may
2678 * Dcache size (number of lines) and line-size are now runtime-configurable
2679 via "set dcache line" and "set dcache line-size" commands.
2683 Texas Instruments TMS320C6x tic6x-*-*
2687 Renesas RL78 rl78-*-elf
2689 *** Changes in GDB 7.3.1
2691 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2693 *** Changes in GDB 7.3
2695 * GDB has a new command: "thread find [REGEXP]".
2696 It finds the thread id whose name, target id, or thread extra info
2697 matches the given regular expression.
2699 * The "catch syscall" command now works on mips*-linux* targets.
2701 * The -data-disassemble MI command now supports modes 2 and 3 for
2702 dumping the instruction opcodes.
2704 * New command line options
2706 -data-directory DIR Specify DIR as the "data-directory".
2707 This is mostly for testing purposes.
2709 * The "maint set python auto-load on|off" command has been renamed to
2710 "set auto-load-scripts on|off".
2712 * GDB has a new command: "set directories".
2713 It is like the "dir" command except that it replaces the
2714 source path list instead of augmenting it.
2716 * GDB now understands thread names.
2718 On GNU/Linux, "info threads" will display the thread name as set by
2719 prctl or pthread_setname_np.
2721 There is also a new command, "thread name", which can be used to
2722 assign a name internally for GDB to display.
2725 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2726 has been integrated into GDB.
2730 ** The function gdb.Write now accepts an optional keyword 'stream'.
2731 This keyword, when provided, will direct the output to either
2732 stdout, stderr, or GDB's logging output.
2734 ** Parameters can now be be sub-classed in Python, and in particular
2735 you may implement the get_set_doc and get_show_doc functions.
2736 This improves how Parameter set/show documentation is processed
2737 and allows for more dynamic content.
2739 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2740 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2741 have an is_valid method.
2743 ** Breakpoints can now be sub-classed in Python, and in particular
2744 you may implement a 'stop' function that is executed each time
2745 the inferior reaches that breakpoint.
2747 ** New function gdb.lookup_global_symbol looks up a global symbol.
2749 ** GDB values in Python are now callable if the value represents a
2750 function. For example, if 'some_value' represents a function that
2751 takes two integer parameters and returns a value, you can call
2752 that function like so:
2754 result = some_value (10,20)
2756 ** Module gdb.types has been added.
2757 It contains a collection of utilities for working with gdb.Types objects:
2758 get_basic_type, has_field, make_enum_dict.
2760 ** Module gdb.printing has been added.
2761 It contains utilities for writing and registering pretty-printers.
2762 New classes: PrettyPrinter, SubPrettyPrinter,
2763 RegexpCollectionPrettyPrinter.
2764 New function: register_pretty_printer.
2766 ** New commands "info pretty-printers", "enable pretty-printer" and
2767 "disable pretty-printer" have been added.
2769 ** gdb.parameter("directories") is now available.
2771 ** New function gdb.newest_frame returns the newest frame in the
2774 ** The gdb.InferiorThread class has a new "name" attribute. This
2775 holds the thread's name.
2777 ** Python Support for Inferior events.
2778 Python scripts can add observers to be notified of events
2779 occurring in the process being debugged.
2780 The following events are currently supported:
2781 - gdb.events.cont Continue event.
2782 - gdb.events.exited Inferior exited event.
2783 - gdb.events.stop Signal received, and Breakpoint hit events.
2787 ** GDB now puts template parameters in scope when debugging in an
2788 instantiation. For example, if you have:
2790 template<int X> int func (void) { return X; }
2792 then if you step into func<5>, "print X" will show "5". This
2793 feature requires proper debuginfo support from the compiler; it
2794 was added to GCC 4.5.
2796 ** The motion commands "next", "finish", "until", and "advance" now
2797 work better when exceptions are thrown. In particular, GDB will
2798 no longer lose control of the inferior; instead, the GDB will
2799 stop the inferior at the point at which the exception is caught.
2800 This functionality requires a change in the exception handling
2801 code that was introduced in GCC 4.5.
2803 * GDB now follows GCC's rules on accessing volatile objects when
2804 reading or writing target state during expression evaluation.
2805 One notable difference to prior behavior is that "print x = 0"
2806 no longer generates a read of x; the value of the assignment is
2807 now always taken directly from the value being assigned.
2809 * GDB now has some support for using labels in the program's source in
2810 linespecs. For instance, you can use "advance label" to continue
2811 execution to a label.
2813 * GDB now has support for reading and writing a new .gdb_index
2814 section. This section holds a fast index of DWARF debugging
2815 information and can be used to greatly speed up GDB startup and
2816 operation. See the documentation for `save gdb-index' for details.
2818 * The "watch" command now accepts an optional "-location" argument.
2819 When used, this causes GDB to watch the memory referred to by the
2820 expression. Such a watchpoint is never deleted due to it going out
2823 * GDB now supports thread debugging of core dumps on GNU/Linux.
2825 GDB now activates thread debugging using the libthread_db library
2826 when debugging GNU/Linux core dumps, similarly to when debugging
2827 live processes. As a result, when debugging a core dump file, GDB
2828 is now able to display pthread_t ids of threads. For example, "info
2829 threads" shows the same output as when debugging the process when it
2830 was live. In earlier releases, you'd see something like this:
2833 * 1 LWP 6780 main () at main.c:10
2835 While now you see this:
2838 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2840 It is also now possible to inspect TLS variables when debugging core
2843 When debugging a core dump generated on a machine other than the one
2844 used to run GDB, you may need to point GDB at the correct
2845 libthread_db library with the "set libthread-db-search-path"
2846 command. See the user manual for more details on this command.
2848 * When natively debugging programs on PowerPC BookE processors running
2849 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2850 which stop execution of the inferior whenever it executes an instruction
2851 at any address within the specified range. See the "PowerPC Embedded"
2852 section in the user manual for more details.
2854 * New features in the GDB remote stub, GDBserver
2856 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2857 and i686 LynxOS (version 5.x).
2859 ** GDBserver is now supported on Blackfin Linux.
2861 * New native configurations
2863 ia64 HP-UX ia64-*-hpux*
2867 Analog Devices, Inc. Blackfin Processor bfin-*
2869 * Ada task switching is now supported on sparc-elf targets when
2870 debugging a program using the Ravenscar Profile. For more information,
2871 see the "Tasking Support when using the Ravenscar Profile" section
2872 in the GDB user manual.
2874 * Guile support was removed.
2876 * New features in the GNU simulator
2878 ** The --map-info flag lists all known core mappings.
2880 ** CFI flashes may be simulated via the "cfi" device.
2882 *** Changes in GDB 7.2
2884 * Shared library support for remote targets by default
2886 When GDB is configured for a generic, non-OS specific target, like
2887 for example, --target=arm-eabi or one of the many *-*-elf targets,
2888 GDB now queries remote stubs for loaded shared libraries using the
2889 `qXfer:libraries:read' packet. Previously, shared library support
2890 was always disabled for such configurations.
2894 ** Argument Dependent Lookup (ADL)
2896 In C++ ADL lookup directs function search to the namespaces of its
2897 arguments even if the namespace has not been imported.
2907 Here the compiler will search for `foo' in the namespace of 'b'
2908 and find A::foo. GDB now supports this. This construct is commonly
2909 used in the Standard Template Library for operators.
2911 ** Improved User Defined Operator Support
2913 In addition to member operators, GDB now supports lookup of operators
2914 defined in a namespace and imported with a `using' directive, operators
2915 defined in the global scope, operators imported implicitly from an
2916 anonymous namespace, and the ADL operators mentioned in the previous
2918 GDB now also supports proper overload resolution for all the previously
2919 mentioned flavors of operators.
2921 ** static const class members
2923 Printing of static const class members that are initialized in the
2924 class definition has been fixed.
2926 * Windows Thread Information Block access.
2928 On Windows targets, GDB now supports displaying the Windows Thread
2929 Information Block (TIB) structure. This structure is visible either
2930 by using the new command `info w32 thread-information-block' or, by
2931 dereferencing the new convenience variable named `$_tlb', a
2932 thread-specific pointer to the TIB. This feature is also supported
2933 when remote debugging using GDBserver.
2935 * Static tracepoints
2937 Static tracepoints are calls in the user program into a tracing
2938 library. One such library is a port of the LTTng kernel tracer to
2939 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2940 When debugging with GDBserver, GDB now supports combining the GDB
2941 tracepoint machinery with such libraries. For example: the user can
2942 use GDB to probe a static tracepoint marker (a call from the user
2943 program into the tracing library) with the new "strace" command (see
2944 "New commands" below). This creates a "static tracepoint" in the
2945 breakpoint list, that can be manipulated with the same feature set
2946 as fast and regular tracepoints. E.g., collect registers, local and
2947 global variables, collect trace state variables, and define
2948 tracepoint conditions. In addition, the user can collect extra
2949 static tracepoint marker specific data, by collecting the new
2950 $_sdata internal variable. When analyzing the trace buffer, you can
2951 inspect $_sdata like any other variable available to GDB. For more
2952 information, see the "Tracepoints" chapter in GDB user manual. New
2953 remote packets have been defined to support static tracepoints, see
2954 the "New remote packets" section below.
2956 * Better reconstruction of tracepoints after disconnected tracing
2958 GDB will attempt to download the original source form of tracepoint
2959 definitions when starting a trace run, and then will upload these
2960 upon reconnection to the target, resulting in a more accurate
2961 reconstruction of the tracepoints that are in use on the target.
2965 You can now exercise direct control over the ways that GDB can
2966 affect your program. For instance, you can disallow the setting of
2967 breakpoints, so that the program can run continuously (assuming
2968 non-stop mode). In addition, the "observer" variable is available
2969 to switch all of the different controls; in observer mode, GDB
2970 cannot affect the target's behavior at all, which is useful for
2971 tasks like diagnosing live systems in the field.
2973 * The new convenience variable $_thread holds the number of the
2976 * New remote packets
2980 Return the address of the Windows Thread Information Block of a given thread.
2984 In response to several of the tracepoint packets, the target may now
2985 also respond with a number of intermediate `qRelocInsn' request
2986 packets before the final result packet, to have GDB handle
2987 relocating an instruction to execute at a different address. This
2988 is particularly useful for stubs that support fast tracepoints. GDB
2989 reports support for this feature in the qSupported packet.
2993 List static tracepoint markers in the target program.
2997 List static tracepoint markers at a given address in the target
3000 qXfer:statictrace:read
3002 Read the static trace data collected (by a `collect $_sdata'
3003 tracepoint action). The remote stub reports support for this packet
3004 to gdb's qSupported query.
3008 Send the current settings of GDB's permission flags.
3012 Send part of the source (textual) form of a tracepoint definition,
3013 which includes location, conditional, and action list.
3015 * The source command now accepts a -s option to force searching for the
3016 script in the source search path even if the script name specifies
3019 * New features in the GDB remote stub, GDBserver
3021 - GDBserver now support tracepoints (including fast tracepoints, and
3022 static tracepoints). The feature is currently supported by the
3023 i386-linux and amd64-linux builds. See the "Tracepoints support
3024 in gdbserver" section in the manual for more information.
3026 GDBserver JIT compiles the tracepoint's conditional agent
3027 expression bytecode into native code whenever possible for low
3028 overhead dynamic tracepoints conditionals. For such tracepoints,
3029 an expression that examines program state is evaluated when the
3030 tracepoint is reached, in order to determine whether to capture
3031 trace data. If the condition is simple and false, processing the
3032 tracepoint finishes very quickly and no data is gathered.
3034 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3035 for static tracepoints support.
3037 - GDBserver now supports x86_64 Windows 64-bit debugging.
3039 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3040 it understands register description.
3042 * The --batch flag now disables pagination and queries.
3044 * X86 general purpose registers
3046 GDB now supports reading/writing byte, word and double-word x86
3047 general purpose registers directly. This means you can use, say,
3048 $ah or $ax to refer, respectively, to the byte register AH and
3049 16-bit word register AX that are actually portions of the 32-bit
3050 register EAX or 64-bit register RAX.
3052 * The `commands' command now accepts a range of breakpoints to modify.
3053 A plain `commands' following a command that creates multiple
3054 breakpoints affects all the breakpoints set by that command. This
3055 applies to breakpoints set by `rbreak', and also applies when a
3056 single `break' command creates multiple breakpoints (e.g.,
3057 breakpoints on overloaded c++ functions).
3059 * The `rbreak' command now accepts a filename specification as part of
3060 its argument, limiting the functions selected by the regex to those
3061 in the specified file.
3063 * Support for remote debugging Windows and SymbianOS shared libraries
3064 from Unix hosts has been improved. Non Windows GDB builds now can
3065 understand target reported file names that follow MS-DOS based file
3066 system semantics, such as file names that include drive letters and
3067 use the backslash character as directory separator. This makes it
3068 possible to transparently use the "set sysroot" and "set
3069 solib-search-path" on Unix hosts to point as host copies of the
3070 target's shared libraries. See the new command "set
3071 target-file-system-kind" described below, and the "Commands to
3072 specify files" section in the user manual for more information.
3076 eval template, expressions...
3077 Convert the values of one or more expressions under the control
3078 of the string template to a command line, and call it.
3080 set target-file-system-kind unix|dos-based|auto
3081 show target-file-system-kind
3082 Set or show the assumed file system kind for target reported file
3085 save breakpoints <filename>
3086 Save all current breakpoint definitions to a file suitable for use
3087 in a later debugging session. To read the saved breakpoint
3088 definitions, use the `source' command.
3090 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3093 info static-tracepoint-markers
3094 Display information about static tracepoint markers in the target.
3096 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3097 Define a static tracepoint by probing a marker at the given
3098 function, line, address, or marker ID.
3102 Enable and disable observer mode.
3104 set may-write-registers on|off
3105 set may-write-memory on|off
3106 set may-insert-breakpoints on|off
3107 set may-insert-tracepoints on|off
3108 set may-insert-fast-tracepoints on|off
3109 set may-interrupt on|off
3110 Set individual permissions for GDB effects on the target. Note that
3111 some of these settings can have undesirable or surprising
3112 consequences, particularly when changed in the middle of a session.
3113 For instance, disabling the writing of memory can prevent
3114 breakpoints from being inserted, cause single-stepping to fail, or
3115 even crash your program, if you disable after breakpoints have been
3116 inserted. However, GDB should not crash.
3118 set record memory-query on|off
3119 show record memory-query
3120 Control whether to stop the inferior if memory changes caused
3121 by an instruction cannot be recorded.
3126 The disassemble command now supports "start,+length" form of two arguments.
3130 ** GDB now provides a new directory location, called the python directory,
3131 where Python scripts written for GDB can be installed. The location
3132 of that directory is <data-directory>/python, where <data-directory>
3133 is the GDB data directory. For more details, see section `Scripting
3134 GDB using Python' in the manual.
3136 ** The GDB Python API now has access to breakpoints, symbols, symbol
3137 tables, program spaces, inferiors, threads and frame's code blocks.
3138 Additionally, GDB Parameters can now be created from the API, and
3139 manipulated via set/show in the CLI.
3141 ** New functions gdb.target_charset, gdb.target_wide_charset,
3142 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3144 ** New exception gdb.GdbError.
3146 ** Pretty-printers are now also looked up in the current program space.
3148 ** Pretty-printers can now be individually enabled and disabled.
3150 ** GDB now looks for names of Python scripts to auto-load in a
3151 special section named `.debug_gdb_scripts', in addition to looking
3152 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3154 * Tracepoint actions were unified with breakpoint commands. In particular,
3155 there are no longer differences in "info break" output for breakpoints and
3156 tracepoints and the "commands" command can be used for both tracepoints and
3157 regular breakpoints.
3161 ARM Symbian arm*-*-symbianelf*
3163 * D language support.
3164 GDB now supports debugging programs written in the D programming
3167 * GDB now supports the extended ptrace interface for PowerPC which is
3168 available since Linux kernel version 2.6.34. This automatically enables
3169 any hardware breakpoints and additional hardware watchpoints available in
3170 the processor. The old ptrace interface exposes just one hardware
3171 watchpoint and no hardware breakpoints.
3173 * GDB is now able to use the Data Value Compare (DVC) register available on
3174 embedded PowerPC processors to implement in hardware simple watchpoint
3175 conditions of the form:
3177 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3179 This works in native GDB running on Linux kernels with the extended ptrace
3180 interface mentioned above.
3182 *** Changes in GDB 7.1
3186 ** Namespace Support
3188 GDB now supports importing of namespaces in C++. This enables the
3189 user to inspect variables from imported namespaces. Support for
3190 namepace aliasing has also been added. So, if a namespace is
3191 aliased in the current scope (e.g. namepace C=A; ) the user can
3192 print variables using the alias (e.g. (gdb) print C::x).
3196 All known bugs relating to the printing of virtual base class were
3197 fixed. It is now possible to call overloaded static methods using a
3202 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3203 and reinterpret_cast<> are now handled by the C++ expression parser.
3207 Xilinx MicroBlaze microblaze-*-*
3212 Xilinx MicroBlaze microblaze
3215 * Multi-program debugging.
3217 GDB now has support for multi-program (a.k.a. multi-executable or
3218 multi-exec) debugging. This allows for debugging multiple inferiors
3219 simultaneously each running a different program under the same GDB
3220 session. See "Debugging Multiple Inferiors and Programs" in the
3221 manual for more information. This implied some user visible changes
3222 in the multi-inferior support. For example, "info inferiors" now
3223 lists inferiors that are not running yet or that have exited
3224 already. See also "New commands" and "New options" below.
3226 * New tracing features
3228 GDB's tracepoint facility now includes several new features:
3230 ** Trace state variables
3232 GDB tracepoints now include support for trace state variables, which
3233 are variables managed by the target agent during a tracing
3234 experiment. They are useful for tracepoints that trigger each
3235 other, so for instance one tracepoint can count hits in a variable,
3236 and then a second tracepoint has a condition that is true when the
3237 count reaches a particular value. Trace state variables share the
3238 $-syntax of GDB convenience variables, and can appear in both
3239 tracepoint actions and condition expressions. Use the "tvariable"
3240 command to create, and "info tvariables" to view; see "Trace State
3241 Variables" in the manual for more detail.
3245 GDB now includes an option for defining fast tracepoints, which
3246 targets may implement more efficiently, such as by installing a jump
3247 into the target agent rather than a trap instruction. The resulting
3248 speedup can be by two orders of magnitude or more, although the
3249 tradeoff is that some program locations on some target architectures
3250 might not allow fast tracepoint installation, for instance if the
3251 instruction to be replaced is shorter than the jump. To request a
3252 fast tracepoint, use the "ftrace" command, with syntax identical to
3253 the regular trace command.
3255 ** Disconnected tracing
3257 It is now possible to detach GDB from the target while it is running
3258 a trace experiment, then reconnect later to see how the experiment
3259 is going. In addition, a new variable disconnected-tracing lets you
3260 tell the target agent whether to continue running a trace if the
3261 connection is lost unexpectedly.
3265 GDB now has the ability to save the trace buffer into a file, and
3266 then use that file as a target, similarly to you can do with
3267 corefiles. You can select trace frames, print data that was
3268 collected in them, and use tstatus to display the state of the
3269 tracing run at the moment that it was saved. To create a trace
3270 file, use "tsave <filename>", and to use it, do "target tfile
3273 ** Circular trace buffer
3275 You can ask the target agent to handle the trace buffer as a
3276 circular buffer, discarding the oldest trace frames to make room for
3277 newer ones, by setting circular-trace-buffer to on. This feature may
3278 not be available for all target agents.
3283 The disassemble command, when invoked with two arguments, now requires
3284 the arguments to be comma-separated.
3287 The info variables command now displays variable definitions. Files
3288 which only declare a variable are not shown.
3291 The source command is now capable of sourcing Python scripts.
3292 This feature is dependent on the debugger being build with Python
3295 Related to this enhancement is also the introduction of a new command
3296 "set script-extension" (see below).
3298 * New commands (for set/show, see "New options" below)
3300 record save [<FILENAME>]
3301 Save a file (in core file format) containing the process record
3302 execution log for replay debugging at a later time.
3304 record restore <FILENAME>
3305 Restore the process record execution log that was saved at an
3306 earlier time, for replay debugging.
3308 add-inferior [-copies <N>] [-exec <FILENAME>]
3311 clone-inferior [-copies <N>] [ID]
3312 Make a new inferior ready to execute the same program another
3313 inferior has loaded.
3318 maint info program-spaces
3319 List the program spaces loaded into GDB.
3321 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3322 show remote interrupt-sequence
3323 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3324 as the sequence to the remote target in order to interrupt the execution.
3325 Ctrl-C is a default. Some system prefers BREAK which is high level of
3326 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3327 Magic SysRq g. It is BREAK signal and character 'g'.
3329 set remote interrupt-on-connect [on | off]
3330 show remote interrupt-on-connect
3331 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3332 remote target when gdb connects to it. This is needed when you debug
3335 set remotebreak [on | off]
3337 Deprecated. Use "set/show remote interrupt-sequence" instead.
3339 tvariable $NAME [ = EXP ]
3340 Create or modify a trace state variable.
3343 List trace state variables and their values.
3345 delete tvariable $NAME ...
3346 Delete one or more trace state variables.
3349 Evaluate the given expressions without collecting anything into the
3350 trace buffer. (Valid in tracepoint actions only.)
3352 ftrace FN / FILE:LINE / *ADDR
3353 Define a fast tracepoint at the given function, line, or address.
3355 * New expression syntax
3357 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3358 GDB now parses 0b101010 identically with 42.
3362 set follow-exec-mode new|same
3363 show follow-exec-mode
3364 Control whether GDB reuses the same inferior across an exec call or
3365 creates a new one. This is useful to be able to restart the old
3366 executable after the inferior having done an exec call.
3368 set default-collect EXPR, ...
3369 show default-collect
3370 Define a list of expressions to be collected at each tracepoint.
3371 This is a useful way to ensure essential items are not overlooked,
3372 such as registers or a critical global variable.
3374 set disconnected-tracing
3375 show disconnected-tracing
3376 If set to 1, the target is instructed to continue tracing if it
3377 loses its connection to GDB. If 0, the target is to stop tracing
3380 set circular-trace-buffer
3381 show circular-trace-buffer
3382 If set to on, the target is instructed to use a circular trace buffer
3383 and discard the oldest trace frames instead of stopping the trace due
3384 to a full trace buffer. If set to off, the trace stops when the buffer
3385 fills up. Some targets may not support this.
3387 set script-extension off|soft|strict
3388 show script-extension
3389 If set to "off", the debugger does not perform any script language
3390 recognition, and all sourced files are assumed to be GDB scripts.
3391 If set to "soft" (the default), files are sourced according to
3392 filename extension, falling back to GDB scripts if the first
3394 If set to "strict", files are sourced according to filename extension.
3396 set ada trust-PAD-over-XVS on|off
3397 show ada trust-PAD-over-XVS
3398 If off, activate a workaround against a bug in the debugging information
3399 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3400 the GCC sources for more information about the GNAT encoding and
3401 PAD types in particular). It is always safe to set this option to
3402 off, but this introduces a slight performance penalty. The default
3405 * Python API Improvements
3407 ** GDB provides the new class gdb.LazyString. This is useful in
3408 some pretty-printing cases. The new method gdb.Value.lazy_string
3409 provides a simple way to create objects of this type.
3411 ** The fields returned by gdb.Type.fields now have an
3412 `is_base_class' attribute.
3414 ** The new method gdb.Type.range returns the range of an array type.
3416 ** The new method gdb.parse_and_eval can be used to parse and
3417 evaluate an expression.
3419 * New remote packets
3422 Define a trace state variable.
3425 Get the current value of a trace state variable.
3428 Set desired tracing behavior upon disconnection.
3431 Set the trace buffer to be linear or circular.
3434 Get data about the tracepoints currently in use.
3438 Process record now works correctly with hardware watchpoints.
3440 Multiple bug fixes have been made to the mips-irix port, making it
3441 much more reliable. In particular:
3442 - Debugging threaded applications is now possible again. Previously,
3443 GDB would hang while starting the program, or while waiting for
3444 the program to stop at a breakpoint.
3445 - Attaching to a running process no longer hangs.
3446 - An error occurring while loading a core file has been fixed.
3447 - Changing the value of the PC register now works again. This fixes
3448 problems observed when using the "jump" command, or when calling
3449 a function from GDB, or even when assigning a new value to $pc.
3450 - With the "finish" and "return" commands, the return value for functions
3451 returning a small array is now correctly printed.
3452 - It is now possible to break on shared library code which gets executed
3453 during a shared library init phase (code executed while executing
3454 their .init section). Previously, the breakpoint would have no effect.
3455 - GDB is now able to backtrace through the signal handler for
3456 non-threaded programs.
3458 PIE (Position Independent Executable) programs debugging is now supported.
3459 This includes debugging execution of PIC (Position Independent Code) shared
3460 libraries although for that, it should be possible to run such libraries as an
3463 *** Changes in GDB 7.0
3465 * GDB now has an interface for JIT compilation. Applications that
3466 dynamically generate code can create symbol files in memory and register
3467 them with GDB. For users, the feature should work transparently, and
3468 for JIT developers, the interface is documented in the GDB manual in the
3469 "JIT Compilation Interface" chapter.
3471 * Tracepoints may now be conditional. The syntax is as for
3472 breakpoints; either an "if" clause appended to the "trace" command,
3473 or the "condition" command is available. GDB sends the condition to
3474 the target for evaluation using the same bytecode format as is used
3475 for tracepoint actions.
3477 * The disassemble command now supports: an optional /r modifier, print the
3478 raw instructions in hex as well as in symbolic form, and an optional /m
3479 modifier to print mixed source+assembly.
3481 * Process record and replay
3483 In a architecture environment that supports ``process record and
3484 replay'', ``process record and replay'' target can record a log of
3485 the process execution, and replay it with both forward and reverse
3488 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3489 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3490 set execution-direction {forward|reverse}, for targets that support
3493 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3494 feature is available with a native GDB running on kernel version
3497 * GDB now has support for multi-byte and wide character sets on the
3498 target. Strings whose character type is wchar_t, char16_t, or
3499 char32_t are now correctly printed. GDB supports wide- and unicode-
3500 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3501 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3502 `printf'. This feature requires iconv to work properly; if your
3503 system does not have a working iconv, GDB can use GNU libiconv. See
3504 the installation instructions for more information.
3506 * GDB now supports automatic retrieval of shared library files from
3507 remote targets. To use this feature, specify a system root that begins
3508 with the `remote:' prefix, either via the `set sysroot' command or via
3509 the `--with-sysroot' configure-time option.
3511 * "info sharedlibrary" now takes an optional regex of libraries to show,
3512 and it now reports if a shared library has no debugging information.
3514 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3515 now complete on file names.
3517 * When completing in expressions, gdb will attempt to limit
3518 completions to allowable structure or union fields, where appropriate.
3519 For instance, consider:
3521 # struct example { int f1; double f2; };
3522 # struct example variable;
3525 If the user types TAB at the end of this command line, the available
3526 completions will be "f1" and "f2".
3528 * Inlined functions are now supported. They show up in backtraces, and
3529 the "step", "next", and "finish" commands handle them automatically.
3531 * GDB now supports the token-splicing (##) and stringification (#)
3532 operators when expanding macros. It also supports variable-arity
3535 * GDB now supports inspecting extra signal information, exported by
3536 the new $_siginfo convenience variable. The feature is currently
3537 implemented on linux ARM, i386 and amd64.
3539 * GDB can now display the VFP floating point registers and NEON vector
3540 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3541 can provide these registers (requires Linux 2.6.30 or later). Remote
3542 and simulator targets may also provide them.
3544 * New remote packets
3547 Search memory for a sequence of bytes.
3550 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3551 operation over reliable transport links. Use of this packet is
3552 controlled by the `set remote noack-packet' command.
3555 Kill the process with the specified process ID. Use this in preference
3556 to `k' when multiprocess protocol extensions are supported.
3559 Obtains additional operating system information
3563 Read or write additional signal information.
3565 * Removed remote protocol undocumented extension
3567 An undocumented extension to the remote protocol's `S' stop reply
3568 packet that permited the stub to pass a process id was removed.
3569 Remote servers should use the `T' stop reply packet instead.
3571 * GDB now supports multiple function calling conventions according to the
3572 DWARF-2 DW_AT_calling_convention function attribute.
3574 * The SH target utilizes the aforementioned change to distinguish between gcc
3575 and Renesas calling convention. It also adds the new CLI commands
3576 `set/show sh calling-convention'.
3578 * GDB can now read compressed debug sections, as produced by GNU gold
3579 with the --compress-debug-sections=zlib flag.
3581 * 64-bit core files are now supported on AIX.
3583 * Thread switching is now supported on Tru64.
3585 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3586 which will be allocated using malloc later in program execution.
3588 * The qXfer:libraries:read remote procotol packet now allows passing a
3589 list of section offsets.
3591 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3592 conditions handling signals delivered during attach or thread creation
3593 have also been fixed.
3595 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3596 From the user's standpoint, all unqualified instances of True and False
3597 are treated as the standard definitions, regardless of context.
3599 * GDB now parses C++ symbol and type names more flexibly. For
3602 template<typename T> class C { };
3605 GDB will now correctly handle all of:
3607 ptype C<char const *>
3608 ptype C<char const*>
3609 ptype C<const char *>
3610 ptype C<const char*>
3612 * New features in the GDB remote stub, gdbserver
3614 - The "--wrapper" command-line argument tells gdbserver to use a
3615 wrapper program to launch programs for debugging.
3617 - On PowerPC and S/390 targets, it is now possible to use a single
3618 gdbserver executable to debug both 32-bit and 64-bit programs.
3619 (This requires gdbserver itself to be built as a 64-bit executable.)
3621 - gdbserver uses the new noack protocol mode for TCP connections to
3622 reduce communications latency, if also supported and enabled in GDB.
3624 - Support for the sparc64-linux-gnu target is now included in
3627 - The amd64-linux build of gdbserver now supports debugging both
3628 32-bit and 64-bit programs.
3630 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3631 now support hardware watchpoints, and will use them automatically
3636 GDB now has support for scripting using Python. Whether this is
3637 available is determined at configure time.
3639 New GDB commands can now be written in Python.
3641 * Ada tasking support
3643 Ada tasks can now be inspected in GDB. The following commands have
3647 Print the list of Ada tasks.
3649 Print detailed information about task number N.
3651 Print the task number of the current task.
3653 Switch the context of debugging to task number N.
3655 * Support for user-defined prefixed commands. The "define" command can
3656 add new commands to existing prefixes, e.g. "target".
3658 * Multi-inferior, multi-process debugging.
3660 GDB now has generalized support for multi-inferior debugging. See
3661 "Debugging Multiple Inferiors" in the manual for more information.
3662 Although availability still depends on target support, the command
3663 set is more uniform now. The GNU/Linux specific multi-forks support
3664 has been migrated to this new framework. This implied some user
3665 visible changes; see "New commands" and also "Removed commands"
3668 * Target descriptions can now describe the target OS ABI. See the
3669 "Target Description Format" section in the user manual for more
3672 * Target descriptions can now describe "compatible" architectures
3673 to indicate that the target can execute applications for a different
3674 architecture in addition to those for the main target architecture.
3675 See the "Target Description Format" section in the user manual for
3678 * Multi-architecture debugging.
3680 GDB now includes general supports for debugging applications on
3681 hybrid systems that use more than one single processor architecture
3682 at the same time. Each such hybrid architecture still requires
3683 specific support to be added. The only hybrid architecture supported
3684 in this version of GDB is the Cell Broadband Engine.
3686 * GDB now supports integrated debugging of Cell/B.E. applications that
3687 use both the PPU and SPU architectures. To enable support for hybrid
3688 Cell/B.E. debugging, you need to configure GDB to support both the
3689 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3690 --enable-targets configure option.
3692 * Non-stop mode debugging.
3694 For some targets, GDB now supports an optional mode of operation in
3695 which you can examine stopped threads while other threads continue
3696 to execute freely. This is referred to as non-stop mode, with the
3697 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3698 section in the user manual for more information.
3700 To be able to support remote non-stop debugging, a remote stub needs
3701 to implement the non-stop mode remote protocol extensions, as
3702 described in the "Remote Non-Stop" section of the user manual. The
3703 GDB remote stub, gdbserver, has been adjusted to support these
3704 extensions on linux targets.
3706 * New commands (for set/show, see "New options" below)
3708 catch syscall [NAME(S) | NUMBER(S)]
3709 Catch system calls. Arguments, which should be names of system
3710 calls or their numbers, mean catch only those syscalls. Without
3711 arguments, every syscall will be caught. When the inferior issues
3712 any of the specified syscalls, GDB will stop and announce the system
3713 call, both when it is called and when its call returns. This
3714 feature is currently available with a native GDB running on the
3715 Linux Kernel, under the following architectures: x86, x86_64,
3716 PowerPC and PowerPC64.
3718 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3720 Search memory for a sequence of bytes.
3722 maint set python print-stack
3723 maint show python print-stack
3724 Show a stack trace when an error is encountered in a Python script.
3727 Invoke CODE by passing it to the Python interpreter.
3732 These allow macros to be defined, undefined, and listed
3736 Show operating system information about processes.
3739 List the inferiors currently under GDB's control.
3742 Switch focus to inferior number NUM.
3745 Detach from inferior number NUM.
3748 Kill inferior number NUM.
3752 set spu stop-on-load
3753 show spu stop-on-load
3754 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3756 set spu auto-flush-cache
3757 show spu auto-flush-cache
3758 Control whether to automatically flush the software-managed cache
3759 during Cell/B.E. debugging.
3761 set sh calling-convention
3762 show sh calling-convention
3763 Control the calling convention used when calling SH target functions.
3766 show debug timestamp
3767 Control display of timestamps with GDB debugging output.
3769 set disassemble-next-line
3770 show disassemble-next-line
3771 Control display of disassembled source lines or instructions when
3774 set remote noack-packet
3775 show remote noack-packet
3776 Set/show the use of remote protocol QStartNoAckMode packet. See above
3777 under "New remote packets."
3779 set remote query-attached-packet
3780 show remote query-attached-packet
3781 Control use of remote protocol `qAttached' (query-attached) packet.
3783 set remote read-siginfo-object
3784 show remote read-siginfo-object
3785 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3788 set remote write-siginfo-object
3789 show remote write-siginfo-object
3790 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3793 set remote reverse-continue
3794 show remote reverse-continue
3795 Control use of remote protocol 'bc' (reverse-continue) packet.
3797 set remote reverse-step
3798 show remote reverse-step
3799 Control use of remote protocol 'bs' (reverse-step) packet.
3801 set displaced-stepping
3802 show displaced-stepping
3803 Control displaced stepping mode. Displaced stepping is a way to
3804 single-step over breakpoints without removing them from the debuggee.
3805 Also known as "out-of-line single-stepping".
3808 show debug displaced
3809 Control display of debugging info for displaced stepping.
3811 maint set internal-error
3812 maint show internal-error
3813 Control what GDB does when an internal error is detected.
3815 maint set internal-warning
3816 maint show internal-warning
3817 Control what GDB does when an internal warning is detected.
3822 Use a wrapper program to launch programs for debugging.
3824 set multiple-symbols (all|ask|cancel)
3825 show multiple-symbols
3826 The value of this variable can be changed to adjust the debugger behavior
3827 when an expression or a breakpoint location contains an ambiguous symbol
3828 name (an overloaded function name, for instance).
3830 set breakpoint always-inserted
3831 show breakpoint always-inserted
3832 Keep breakpoints always inserted in the target, as opposed to inserting
3833 them when resuming the target, and removing them when the target stops.
3834 This option can improve debugger performance on slow remote targets.
3836 set arm fallback-mode (arm|thumb|auto)
3837 show arm fallback-mode
3838 set arm force-mode (arm|thumb|auto)
3840 These commands control how ARM GDB determines whether instructions
3841 are ARM or Thumb. The default for both settings is auto, which uses
3842 the current CPSR value for instructions without symbols; previous
3843 versions of GDB behaved as if "set arm fallback-mode arm".
3845 set disable-randomization
3846 show disable-randomization
3847 Standalone programs run with the virtual address space randomization enabled
3848 by default on some platforms. This option keeps the addresses stable across
3849 multiple debugging sessions.
3853 Control whether other threads are stopped or not when some thread hits
3858 Requests that asynchronous execution is enabled in the target, if available.
3859 In this case, it's possible to resume target in the background, and interact
3860 with GDB while the target is running. "show target-async" displays the
3861 current state of asynchronous execution of the target.
3863 set target-wide-charset
3864 show target-wide-charset
3865 The target-wide-charset is the name of the character set that GDB
3866 uses when printing characters whose type is wchar_t.
3868 set tcp auto-retry (on|off)
3870 set tcp connect-timeout
3871 show tcp connect-timeout
3872 These commands allow GDB to retry failed TCP connections to a remote stub
3873 with a specified timeout period; this is useful if the stub is launched
3874 in parallel with GDB but may not be ready to accept connections immediately.
3876 set libthread-db-search-path
3877 show libthread-db-search-path
3878 Control list of directories which GDB will search for appropriate
3881 set schedule-multiple (on|off)
3882 show schedule-multiple
3883 Allow GDB to resume all threads of all processes or only threads of
3884 the current process.
3888 Use more aggressive caching for accesses to the stack. This improves
3889 performance of remote debugging (particularly backtraces) without
3890 affecting correctness.
3892 set interactive-mode (on|off|auto)
3893 show interactive-mode
3894 Control whether GDB runs in interactive mode (on) or not (off).
3895 When in interactive mode, GDB waits for the user to answer all
3896 queries. Otherwise, GDB does not wait and assumes the default
3897 answer. When set to auto (the default), GDB determines which
3898 mode to use based on the stdin settings.
3903 For program forks, this is replaced by the new more generic `info
3904 inferiors' command. To list checkpoints, you can still use the
3905 `info checkpoints' command, which was an alias for the `info forks'
3909 Replaced by the new `inferior' command. To switch between
3910 checkpoints, you can still use the `restart' command, which was an
3911 alias for the `fork' command.
3914 This is removed, since some targets don't have a notion of
3915 processes. To switch between processes, you can still use the
3916 `inferior' command using GDB's own inferior number.
3919 For program forks, this is replaced by the new more generic `kill
3920 inferior' command. To delete a checkpoint, you can still use the
3921 `delete checkpoint' command, which was an alias for the `delete
3925 For program forks, this is replaced by the new more generic `detach
3926 inferior' command. To detach a checkpoint, you can still use the
3927 `detach checkpoint' command, which was an alias for the `detach
3930 * New native configurations
3932 x86/x86_64 Darwin i[34567]86-*-darwin*
3934 x86_64 MinGW x86_64-*-mingw*
3938 Lattice Mico32 lm32-*
3939 x86 DICOS i[34567]86-*-dicos*
3940 x86_64 DICOS x86_64-*-dicos*
3943 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3944 (mingw32ce) debugging.
3950 These commands were actually not implemented on any target.
3952 *** Changes in GDB 6.8
3954 * New native configurations
3956 NetBSD/hppa hppa*-*netbsd*
3957 Xtensa GNU/Linux xtensa*-*-linux*
3961 NetBSD/hppa hppa*-*-netbsd*
3962 Xtensa GNU/Lunux xtensa*-*-linux*
3964 * Change in command line behavior -- corefiles vs. process ids.
3966 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3967 attaching to process NUMBER fails, GDB no longer attempts to open a
3968 core file named NUMBER. Attaching to a program using the -c option
3969 is no longer supported. Instead, use the '-p' or '--pid' options.
3971 * GDB can now be built as a native debugger for debugging Windows x86
3972 (mingw32) Portable Executable (PE) programs.
3974 * Pending breakpoints no longer change their number when their address
3977 * GDB now supports breakpoints with multiple locations,
3978 including breakpoints on C++ constructors, inside C++ templates,
3979 and in inlined functions.
3981 * GDB's ability to debug optimized code has been improved. GDB more
3982 accurately identifies function bodies and lexical blocks that occupy
3983 more than one contiguous range of addresses.
3985 * Target descriptions can now describe registers for PowerPC.
3987 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3988 registers on PowerPC targets.
3990 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3991 targets even when the libthread_db library is not available.
3993 * The GDB remote stub, gdbserver, now supports the new file transfer
3994 commands (remote put, remote get, and remote delete).
3996 * The GDB remote stub, gdbserver, now supports run and attach in
3997 extended-remote mode.
3999 * hppa*64*-*-hpux11* target broken
4000 The debugger is unable to start a program and fails with the following
4001 error: "Error trying to get information about dynamic linker".
4002 The gdb-6.7 release is also affected.
4004 * GDB now supports the --enable-targets= configure option to allow
4005 building a single GDB executable that supports multiple remote
4006 target architectures.
4008 * GDB now supports debugging C and C++ programs which use the
4009 Decimal Floating Point extension. In addition, the PowerPC target
4010 now has a set of pseudo-registers to inspect decimal float values
4011 stored in two consecutive float registers.
4013 * The -break-insert MI command can optionally create pending
4016 * Improved support for debugging Ada
4017 Many improvements to the Ada language support have been made. These
4019 - Better support for Ada2005 interface types
4020 - Improved handling of arrays and slices in general
4021 - Better support for Taft-amendment types
4022 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4024 - Improved command completion in Ada
4027 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4032 set print frame-arguments (all|scalars|none)
4033 show print frame-arguments
4034 The value of this variable can be changed to control which argument
4035 values should be printed by the debugger when displaying a frame.
4040 Transfer files to and from a remote target, and delete remote files.
4047 Transfer files to and from a remote target, and delete remote files.
4049 * New remote packets
4056 Open, close, read, write, and delete files on the remote system.
4059 Attach to an existing process on the remote system, in extended-remote
4063 Run a new process on the remote system, in extended-remote mode.
4065 *** Changes in GDB 6.7
4067 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4068 bfd, libiberty and opcodes, as revealed by static analysis donated by
4069 Coverity, Inc. (http://scan.coverity.com).
4071 * When looking up multiply-defined global symbols, GDB will now prefer the
4072 symbol definition in the current shared library if it was built using the
4073 -Bsymbolic linker option.
4075 * When the Text User Interface (TUI) is not configured, GDB will now
4076 recognize the -tui command-line option and print a message that the TUI
4079 * The GDB remote stub, gdbserver, now has lower overhead for high
4080 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4082 * GDB for MIPS targets now autodetects whether a remote target provides
4083 32-bit or 64-bit register values.
4085 * Support for C++ member pointers has been improved.
4087 * GDB now understands XML target descriptions, which specify the
4088 target's overall architecture. GDB can read a description from
4089 a local file or over the remote serial protocol.
4091 * Vectors of single-byte data use a new integer type which is not
4092 automatically displayed as character or string data.
4094 * The /s format now works with the print command. It displays
4095 arrays of single-byte integers and pointers to single-byte integers
4098 * Target descriptions can now describe target-specific registers,
4099 for architectures which have implemented the support (currently
4100 only ARM, M68K, and MIPS).
4102 * GDB and the GDB remote stub, gdbserver, now support the XScale
4105 * The GDB remote stub, gdbserver, has been updated to support
4106 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4107 has been rewritten to use the standard GDB remote protocol.
4109 * GDB can now step into C++ functions which are called through thunks.
4111 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4113 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4114 layout. It also supports a TextSeg= and DataSeg= response when only
4115 segment base addresses (rather than offsets) are available.
4117 * The /i format now outputs any trailing branch delay slot instructions
4118 immediately following the last instruction within the count specified.
4120 * The GDB remote protocol "T" stop reply packet now supports a
4121 "library" response. Combined with the new "qXfer:libraries:read"
4122 packet, this response allows GDB to debug shared libraries on targets
4123 where the operating system manages the list of loaded libraries (e.g.
4124 Windows and SymbianOS).
4126 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4127 (DLLs) on Windows and Windows CE targets.
4129 * GDB now supports a faster verification that a .debug file matches its binary
4130 according to its build-id signature, if the signature is present.
4136 Enable or disable hardware flow control (RTS/CTS) on the serial port
4137 when debugging using remote targets.
4139 set mem inaccessible-by-default
4140 show mem inaccessible-by-default
4141 If the target supplies a memory map, for instance via the remote
4142 protocol's "qXfer:memory-map:read" packet, setting this variable
4143 prevents GDB from accessing memory outside the memory map. This
4144 is useful for targets with memory mapped registers or which react
4145 badly to accesses of unmapped address space.
4147 set breakpoint auto-hw
4148 show breakpoint auto-hw
4149 If the target supplies a memory map, for instance via the remote
4150 protocol's "qXfer:memory-map:read" packet, setting this variable
4151 lets GDB use hardware breakpoints automatically for memory regions
4152 where it can not use software breakpoints. This covers both the
4153 "break" command and internal breakpoints used for other commands
4154 including "next" and "finish".
4157 catch exception unhandled
4158 Stop the program execution when Ada exceptions are raised.
4161 Stop the program execution when an Ada assertion failed.
4165 Set an alternate system root for target files. This is a more
4166 general version of "set solib-absolute-prefix", which is now
4167 an alias to "set sysroot".
4170 Provide extended SPU facility status information. This set of
4171 commands is available only when debugging the Cell/B.E. SPU
4174 * New native configurations
4176 OpenBSD/sh sh*-*openbsd*
4179 unset tdesc filename
4181 Use the specified local file as an XML target description, and do
4182 not query the target for its built-in description.
4186 OpenBSD/sh sh*-*-openbsd*
4187 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4188 Toshiba Media Processor mep-elf
4190 * New remote packets
4193 Ignore the specified signals; pass them directly to the debugged program
4194 without stopping other threads or reporting them to GDB.
4196 qXfer:features:read:
4197 Read an XML target description from the target, which describes its
4202 Read or write contents of an spufs file on the target system. These
4203 packets are available only on the Cell/B.E. SPU architecture.
4205 qXfer:libraries:read:
4206 Report the loaded shared libraries. Combined with new "T" packet
4207 response, this packet allows GDB to debug shared libraries on
4208 targets where the operating system manages the list of loaded
4209 libraries (e.g. Windows and SymbianOS).
4213 Support for these obsolete configurations has been removed.
4221 i[34567]86-*-lynxos*
4222 i[34567]86-*-netware*
4223 i[34567]86-*-sco3.2v5*
4224 i[34567]86-*-sco3.2v4*
4226 i[34567]86-*-sysv4.2*
4229 i[34567]86-*-unixware2*
4230 i[34567]86-*-unixware*
4239 * Other removed features
4246 Various m68k-only ROM monitors.
4253 Various Renesas ROM monitors and debugging interfaces for SH and
4258 Support for a Macraigor serial interface to on-chip debugging.
4259 GDB does not directly support the newer parallel or USB
4264 A debug information format. The predecessor to DWARF 2 and
4265 DWARF 3, which are still supported.
4267 Support for the HP aCC compiler on HP-UX/PA-RISC
4269 SOM-encapsulated symbolic debugging information, automatic
4270 invocation of pxdb, and the aCC custom C++ ABI. This does not
4271 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4272 with aCC can still be debugged on an assembly level.
4274 MIPS ".pdr" sections
4276 A MIPS-specific format used to describe stack frame layout
4277 in debugging information.
4281 GDB could work with an older version of Guile to debug
4282 the interpreter and Scheme programs running in it.
4284 set mips stack-arg-size
4285 set mips saved-gpreg-size
4287 Use "set mips abi" to control parameter passing for MIPS.
4289 *** Changes in GDB 6.6
4294 Cell Broadband Engine SPU spu-elf
4296 * GDB can now be configured as a cross-debugger targeting native Windows
4297 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4298 running on a Windows system over TCP/IP to debug Windows programs.
4300 * The GDB remote stub, gdbserver, has been updated to support Windows and
4301 Cygwin debugging. Both single-threaded and multi-threaded programs are
4304 * The "set trust-readonly-sections" command works again. This command was
4305 broken in GDB 6.3, 6.4, and 6.5.
4307 * The "load" command now supports writing to flash memory, if the remote
4308 stub provides the required support.
4310 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4311 longer requires symbolic debug information (e.g. DWARF-2).
4316 unset substitute-path
4317 show substitute-path
4318 Manage a list of substitution rules that GDB uses to rewrite the name
4319 of the directories where the sources are located. This can be useful
4320 for instance when the sources were moved to a different location
4321 between compilation and debugging.
4325 Print each CLI command as it is executed. Each command is prefixed with
4326 a number of `+' symbols representing the nesting depth.
4327 The source command now has a `-v' option to enable the same feature.
4331 The ARM Demon monitor support (RDP protocol, "target rdp").
4333 Kernel Object Display, an embedded debugging feature which only worked with
4334 an obsolete version of Cisco IOS.
4336 The 'set download-write-size' and 'show download-write-size' commands.
4338 * New remote packets
4341 Tell a stub about GDB client features, and request remote target features.
4342 The first feature implemented is PacketSize, which allows the target to
4343 specify the size of packets it can handle - to minimize the number of
4344 packets required and improve performance when connected to a remote
4348 Fetch an OS auxilliary vector from the remote stub. This packet is a
4349 more efficient replacement for qPart:auxv:read.
4351 qXfer:memory-map:read:
4352 Fetch a memory map from the remote stub, including information about
4353 RAM, ROM, and flash memory devices.
4358 Erase and program a flash memory device.
4360 * Removed remote packets
4363 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4364 used it, and only gdbserver implemented it.
4366 *** Changes in GDB 6.5
4370 Renesas M32C/M16C m32c-elf
4372 Morpho Technologies ms1 ms1-elf
4376 init-if-undefined Initialize a convenience variable, but
4377 only if it doesn't already have a value.
4379 The following commands are presently only implemented for native GNU/Linux:
4381 checkpoint Save a snapshot of the program state.
4383 restart <n> Return the program state to a
4384 previously saved state.
4386 info checkpoints List currently saved checkpoints.
4388 delete-checkpoint <n> Delete a previously saved checkpoint.
4390 set|show detach-on-fork Tell gdb whether to detach from a newly
4391 forked process, or to keep debugging it.
4393 info forks List forks of the user program that
4394 are available to be debugged.
4396 fork <n> Switch to debugging one of several
4397 forks of the user program that are
4398 available to be debugged.
4400 delete-fork <n> Delete a fork from the list of forks
4401 that are available to be debugged (and
4402 kill the forked process).
4404 detach-fork <n> Delete a fork from the list of forks
4405 that are available to be debugged (and
4406 allow the process to continue).
4410 Morpho Technologies ms2 ms1-elf
4412 * Improved Windows host support
4414 GDB now builds as a cross debugger hosted on i686-mingw32, including
4415 native console support, and remote communications using either
4416 network sockets or serial ports.
4418 * Improved Modula-2 language support
4420 GDB can now print most types in the Modula-2 syntax. This includes:
4421 basic types, set types, record types, enumerated types, range types,
4422 pointer types and ARRAY types. Procedure var parameters are correctly
4423 printed and hexadecimal addresses and character constants are also
4424 written in the Modula-2 syntax. Best results can be obtained by using
4425 GNU Modula-2 together with the -gdwarf-2 command line option.
4429 The ARM rdi-share module.
4431 The Netware NLM debug server.
4433 *** Changes in GDB 6.4
4435 * New native configurations
4437 OpenBSD/arm arm*-*-openbsd*
4438 OpenBSD/mips64 mips64-*-openbsd*
4442 Morpho Technologies ms1 ms1-elf
4444 * New command line options
4446 --batch-silent As for --batch, but totally silent.
4447 --return-child-result The debugger will exist with the same value
4448 the child (debugged) program exited with.
4449 --eval-command COMMAND, -ex COMMAND
4450 Execute a single GDB CLI command. This may be
4451 specified multiple times and in conjunction
4452 with the --command (-x) option.
4454 * Deprecated commands removed
4456 The following commands, that were deprecated in 2000, have been
4460 set|show arm disassembly-flavor set|show arm disassembler
4461 othernames set arm disassembler
4462 set|show remotedebug set|show debug remote
4463 set|show archdebug set|show debug arch
4464 set|show eventdebug set|show debug event
4467 * New BSD user-level threads support
4469 It is now possible to debug programs using the user-level threads
4470 library on OpenBSD and FreeBSD. Currently supported (target)
4473 FreeBSD/amd64 x86_64-*-freebsd*
4474 FreeBSD/i386 i386-*-freebsd*
4475 OpenBSD/i386 i386-*-openbsd*
4477 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4478 are not yet supported.
4480 * New support for Matsushita MN10300 w/sim added
4481 (Work in progress). mn10300-elf.
4483 * REMOVED configurations and files
4485 VxWorks and the XDR protocol *-*-vxworks
4486 Motorola MCORE mcore-*-*
4487 National Semiconductor NS32000 ns32k-*-*
4489 * New "set print array-indexes" command
4491 After turning this setting "on", GDB prints the index of each element
4492 when displaying arrays. The default is "off" to preserve the previous
4495 * VAX floating point support
4497 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4499 * User-defined command support
4501 In addition to using $arg0..$arg9 for argument passing, it is now possible
4502 to use $argc to determine now many arguments have been passed. See the
4503 section on user-defined commands in the user manual for more information.
4505 *** Changes in GDB 6.3:
4507 * New command line option
4509 GDB now accepts -l followed by a number to set the timeout for remote
4512 * GDB works with GCC -feliminate-dwarf2-dups
4514 GDB now supports a more compact representation of DWARF-2 debug
4515 information using DW_FORM_ref_addr references. These are produced
4516 by GCC with the option -feliminate-dwarf2-dups and also by some
4517 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4518 to use -feliminate-dwarf2-dups.
4520 * Internationalization
4522 When supported by the host system, GDB will be built with
4523 internationalization (libintl). The task of marking up the sources is
4524 continued, we're looking forward to our first translation.
4528 Initial support for debugging programs compiled with the GNAT
4529 implementation of the Ada programming language has been integrated
4530 into GDB. In this release, support is limited to expression evaluation.
4532 * New native configurations
4534 GNU/Linux/m32r m32r-*-linux-gnu
4538 GDB's remote protocol now includes support for the 'p' packet. This
4539 packet is used to fetch individual registers from a remote inferior.
4541 * END-OF-LIFE registers[] compatibility module
4543 GDB's internal register infrastructure has been completely rewritten.
4544 The new infrastructure making possible the implementation of key new
4545 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4548 GDB 6.3 will be the last release to include the the registers[]
4549 compatibility module that allowed out-of-date configurations to
4550 continue to work. This change directly impacts the following
4560 powerpc bdm protocol
4562 Unless there is activity to revive these configurations, they will be
4563 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4565 * OBSOLETE configurations and files
4567 Configurations that have been declared obsolete in this release have
4568 been commented out. Unless there is activity to revive these
4569 configurations, the next release of GDB will have their sources
4570 permanently REMOVED.
4579 *** Changes in GDB 6.2.1:
4581 * MIPS `break main; run' gave an heuristic-fence-post warning
4583 When attempting to run even a simple program, a warning about
4584 heuristic-fence-post being hit would be reported. This problem has
4587 * MIPS IRIX 'long double' crashed GDB
4589 When examining a long double variable, GDB would get a segmentation
4590 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4591 IRIX long double values).
4595 A bug in the VAX stack code was causing problems with the "next"
4596 command. This problem has been fixed.
4598 *** Changes in GDB 6.2:
4600 * Fix for ``many threads''
4602 On GNU/Linux systems that use the NPTL threads library, a program
4603 rapidly creating and deleting threads would confuse GDB leading to the
4606 ptrace: No such process.
4607 thread_db_get_info: cannot get thread info: generic error
4609 This problem has been fixed.
4611 * "-async" and "-noasync" options removed.
4613 Support for the broken "-noasync" option has been removed (it caused
4616 * New ``start'' command.
4618 This command runs the program until the begining of the main procedure.
4620 * New BSD Kernel Data Access Library (libkvm) interface
4622 Using ``target kvm'' it is now possible to debug kernel core dumps and
4623 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4624 platforms. Currently supported (native-only) configurations are:
4626 FreeBSD/amd64 x86_64-*-freebsd*
4627 FreeBSD/i386 i?86-*-freebsd*
4628 NetBSD/i386 i?86-*-netbsd*
4629 NetBSD/m68k m68*-*-netbsd*
4630 NetBSD/sparc sparc-*-netbsd*
4631 OpenBSD/amd64 x86_64-*-openbsd*
4632 OpenBSD/i386 i?86-*-openbsd*
4633 OpenBSD/m68k m68*-openbsd*
4634 OpenBSD/sparc sparc-*-openbsd*
4636 * Signal trampoline code overhauled
4638 Many generic problems with GDB's signal handling code have been fixed.
4639 These include: backtraces through non-contiguous stacks; recognition
4640 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4641 call; backtrace through a signal trampoline; step into and out of
4642 signal handlers; and single-stepping in the signal trampoline.
4644 Please note that kernel bugs are a limiting factor here. These
4645 features have been shown to work on an s390 GNU/Linux system that
4646 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4648 * Cygwin support for DWARF 2 added.
4650 * New native configurations
4652 GNU/Linux/hppa hppa*-*-linux*
4653 OpenBSD/hppa hppa*-*-openbsd*
4654 OpenBSD/m68k m68*-*-openbsd*
4655 OpenBSD/m88k m88*-*-openbsd*
4656 OpenBSD/powerpc powerpc-*-openbsd*
4657 NetBSD/vax vax-*-netbsd*
4658 OpenBSD/vax vax-*-openbsd*
4660 * END-OF-LIFE frame compatibility module
4662 GDB's internal frame infrastructure has been completely rewritten.
4663 The new infrastructure making it possible to support key new features
4664 including DWARF 2 Call Frame Information. To aid in the task of
4665 migrating old configurations to this new infrastructure, a
4666 compatibility module, that allowed old configurations to continue to
4667 work, was also included.
4669 GDB 6.2 will be the last release to include this frame compatibility
4670 module. This change directly impacts the following configurations:
4680 Unless there is activity to revive these configurations, they will be
4681 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4683 * REMOVED configurations and files
4685 Sun 3, running SunOS 3 m68*-*-sunos3*
4686 Sun 3, running SunOS 4 m68*-*-sunos4*
4687 Sun 2, running SunOS 3 m68000-*-sunos3*
4688 Sun 2, running SunOS 4 m68000-*-sunos4*
4689 Motorola 680x0 running LynxOS m68*-*-lynxos*
4690 AT&T 3b1/Unix pc m68*-att-*
4691 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4692 decstation mips-dec-* mips-little-*
4693 riscos mips-*-riscos* mips-*-sysv*
4694 sonymips mips-sony-*
4695 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4697 *** Changes in GDB 6.1.1:
4699 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4701 The TUI (Text-mode User Interface) is now built as part of a default
4702 GDB configuration. It is enabled by either selecting the TUI with the
4703 command line option "-i=tui" or by running the separate "gdbtui"
4704 program. For more information on the TUI, see the manual "Debugging
4707 * Pending breakpoint support (also included in GDB 6.1)
4709 Support has been added to allow you to specify breakpoints in shared
4710 libraries that have not yet been loaded. If a breakpoint location
4711 cannot be found, and the "breakpoint pending" option is set to auto,
4712 GDB queries you if you wish to make the breakpoint pending on a future
4713 shared-library load. If and when GDB resolves the breakpoint symbol,
4714 the pending breakpoint is removed as one or more regular breakpoints
4717 Pending breakpoints are very useful for GCJ Java debugging.
4719 * Fixed ISO-C build problems
4721 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4722 non ISO-C code that stopped them being built using a more strict ISO-C
4723 compiler (e.g., IBM's C compiler).
4725 * Fixed build problem on IRIX 5
4727 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4728 wasn't able to compile compile on an IRIX 5 system.
4730 * Added execute permission to gdb/gdbserver/configure
4732 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4733 permission. This bug would cause configure to fail on a number of
4734 systems (Solaris, IRIX). Ref: server/519.
4736 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4738 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4739 has been updated to use constant array sizes.
4741 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4743 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4744 its generated DWARF Call Frame Info. This encoding was causing GDB to
4745 panic, that panic has been fixed. Ref: gdb/1628.
4747 * Fixed a problem when examining parameters in shared library code.
4749 When examining parameters in optimized shared library code generated
4750 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4751 not available''. GDB now correctly displays the variable's value.
4753 *** Changes in GDB 6.1:
4755 * Removed --with-mmalloc
4757 Support for the mmalloc memory manager has been removed, as it
4758 conflicted with the internal gdb byte cache.
4760 * Changes in AMD64 configurations
4762 The AMD64 target now includes the %cs and %ss registers. As a result
4763 the AMD64 remote protocol has changed; this affects the floating-point
4764 and SSE registers. If you rely on those registers for your debugging,
4765 you should upgrade gdbserver on the remote side.
4767 * Revised SPARC target
4769 The SPARC target has been completely revised, incorporating the
4770 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4771 support for LynxOS and SunOS 4 has been dropped. Calling functions
4772 from within GDB on operating systems with a non-executable stack
4773 (Solaris, OpenBSD) now works.
4777 GDB has a new C++ demangler which does a better job on the mangled
4778 names generated by current versions of g++. It also runs faster, so
4779 with this and other changes gdb should now start faster on large C++
4782 * DWARF 2 Location Expressions
4784 GDB support for location expressions has been extended to support function
4785 arguments and frame bases. Older versions of GDB could crash when they
4788 * C++ nested types and namespaces
4790 GDB's support for nested types and namespaces in C++ has been
4791 improved, especially if you use the DWARF 2 debugging format. (This
4792 is the default for recent versions of GCC on most platforms.)
4793 Specifically, if you have a class "Inner" defined within a class or
4794 namespace "Outer", then GDB realizes that the class's name is
4795 "Outer::Inner", not simply "Inner". This should greatly reduce the
4796 frequency of complaints about not finding RTTI symbols. In addition,
4797 if you are stopped at inside of a function defined within a namespace,
4798 GDB modifies its name lookup accordingly.
4800 * New native configurations
4802 NetBSD/amd64 x86_64-*-netbsd*
4803 OpenBSD/amd64 x86_64-*-openbsd*
4804 OpenBSD/alpha alpha*-*-openbsd*
4805 OpenBSD/sparc sparc-*-openbsd*
4806 OpenBSD/sparc64 sparc64-*-openbsd*
4808 * New debugging protocols
4810 M32R with SDI protocol m32r-*-elf*
4812 * "set prompt-escape-char" command deleted.
4814 The command "set prompt-escape-char" has been deleted. This command,
4815 and its very obscure effet on GDB's prompt, was never documented,
4816 tested, nor mentioned in the NEWS file.
4818 * OBSOLETE configurations and files
4820 Configurations that have been declared obsolete in this release have
4821 been commented out. Unless there is activity to revive these
4822 configurations, the next release of GDB will have their sources
4823 permanently REMOVED.
4825 Sun 3, running SunOS 3 m68*-*-sunos3*
4826 Sun 3, running SunOS 4 m68*-*-sunos4*
4827 Sun 2, running SunOS 3 m68000-*-sunos3*
4828 Sun 2, running SunOS 4 m68000-*-sunos4*
4829 Motorola 680x0 running LynxOS m68*-*-lynxos*
4830 AT&T 3b1/Unix pc m68*-att-*
4831 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4832 decstation mips-dec-* mips-little-*
4833 riscos mips-*-riscos* mips-*-sysv*
4834 sonymips mips-sony-*
4835 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4837 * REMOVED configurations and files
4839 SGI Irix-4.x mips-sgi-irix4 or iris4
4840 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4841 Z8000 simulator z8k-zilog-none or z8ksim
4842 Matsushita MN10200 w/simulator mn10200-*-*
4843 H8/500 simulator h8500-hitachi-hms or h8500hms
4844 HP/PA running BSD hppa*-*-bsd*
4845 HP/PA running OSF/1 hppa*-*-osf*
4846 HP/PA Pro target hppa*-*-pro*
4847 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4848 386BSD i[3456]86-*-bsd*
4849 Sequent family i[3456]86-sequent-sysv4*
4850 i[3456]86-sequent-sysv*
4851 i[3456]86-sequent-bsd*
4852 SPARC running LynxOS sparc-*-lynxos*
4853 SPARC running SunOS 4 sparc-*-sunos4*
4854 Tsqware Sparclet sparclet-*-*
4855 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4857 *** Changes in GDB 6.0:
4861 Support for debugging the Objective-C programming language has been
4862 integrated into GDB.
4864 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4866 DWARF 2's Call Frame Information makes available compiler generated
4867 information that more exactly describes the program's run-time stack.
4868 By using this information, GDB is able to provide more robust stack
4871 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4872 have been updated to use a new backtrace mechanism which includes
4873 DWARF 2 CFI support.
4877 GDB's remote protocol has been extended to include support for hosted
4878 file I/O (where the remote target uses GDB's file system). See GDB's
4879 remote protocol documentation for details.
4881 * All targets using the new architecture framework.
4883 All of GDB's targets have been updated to use the new internal
4884 architecture framework. The way is now open for future GDB releases
4885 to include cross-architecture native debugging support (i386 on amd64,
4888 * GNU/Linux's Thread Local Storage (TLS)
4890 GDB now includes support for for the GNU/Linux implementation of
4891 per-thread variables.
4893 * GNU/Linux's Native POSIX Thread Library (NPTL)
4895 GDB's thread code has been updated to work with either the new
4896 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4898 * Separate debug info.
4900 GDB, in conjunction with BINUTILS, now supports a mechanism for
4901 automatically loading debug information from a separate file. Instead
4902 of shipping full debug and non-debug versions of system libraries,
4903 system integrators can now instead ship just the stripped libraries
4904 and optional debug files.
4906 * DWARF 2 Location Expressions
4908 DWARF 2 Location Expressions allow the compiler to more completely
4909 describe the location of variables (even in optimized code) to the
4912 GDB now includes preliminary support for location expressions (support
4913 for DW_OP_piece is still missing).
4917 A number of long standing bugs that caused GDB to die while starting a
4918 Java application have been fixed. GDB's Java support is now
4919 considered "useable".
4921 * GNU/Linux support for fork, vfork, and exec.
4923 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4924 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4927 * GDB supports logging output to a file
4929 There are two new commands, "set logging" and "show logging", which can be
4930 used to capture GDB's output to a file.
4932 * The meaning of "detach" has changed for gdbserver
4934 The "detach" command will now resume the application, as documented. To
4935 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4938 * d10v, m68hc11 `regs' command deprecated
4940 The `info registers' command has been updated so that it displays the
4941 registers using a format identical to the old `regs' command.
4945 A new command, "maint set profile on/off", has been added. This command can
4946 be used to enable or disable profiling while running GDB, to profile a
4947 session or a set of commands. In addition there is a new configure switch,
4948 "--enable-profiling", which will cause GDB to be compiled with profiling
4949 data, for more informative profiling results.
4951 * Default MI syntax changed to "mi2".
4953 The default MI (machine interface) syntax, enabled by the command line
4954 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4955 "mi1", can be enabled by specifying the option "-i=mi1".
4957 Support for the original "mi0" syntax (included in GDB 5.0) has been
4960 Fix for gdb/192: removed extraneous space when displaying frame level.
4961 Fix for gdb/672: update changelist is now output in mi list format.
4962 Fix for gdb/702: a -var-assign that updates the value now shows up
4963 in a subsequent -var-update.
4965 * New native configurations.
4967 FreeBSD/amd64 x86_64-*-freebsd*
4969 * Multi-arched targets.
4971 HP/PA HPUX11 hppa*-*-hpux*
4972 Renesas M32R/D w/simulator m32r-*-elf*
4974 * OBSOLETE configurations and files
4976 Configurations that have been declared obsolete in this release have
4977 been commented out. Unless there is activity to revive these
4978 configurations, the next release of GDB will have their sources
4979 permanently REMOVED.
4981 Z8000 simulator z8k-zilog-none or z8ksim
4982 Matsushita MN10200 w/simulator mn10200-*-*
4983 H8/500 simulator h8500-hitachi-hms or h8500hms
4984 HP/PA running BSD hppa*-*-bsd*
4985 HP/PA running OSF/1 hppa*-*-osf*
4986 HP/PA Pro target hppa*-*-pro*
4987 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4988 Sequent family i[3456]86-sequent-sysv4*
4989 i[3456]86-sequent-sysv*
4990 i[3456]86-sequent-bsd*
4991 Tsqware Sparclet sparclet-*-*
4992 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4994 * REMOVED configurations and files
4997 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4998 IBM AIX PS/2 i[3456]86-*-aix
4999 i386 running Mach 3.0 i[3456]86-*-mach3*
5000 i386 running Mach i[3456]86-*-mach*
5001 i386 running OSF/1 i[3456]86-*osf1mk*
5002 HP/Apollo 68k Family m68*-apollo*-sysv*,
5004 m68*-hp-bsd*, m68*-hp-hpux*
5005 Argonaut Risc Chip (ARC) arc-*-*
5006 Mitsubishi D30V d30v-*-*
5007 Fujitsu FR30 fr30-*-elf*
5008 OS/9000 i[34]86-*-os9k
5009 I960 with MON960 i960-*-coff
5011 * MIPS $fp behavior changed
5013 The convenience variable $fp, for the MIPS, now consistently returns
5014 the address of the current frame's base. Previously, depending on the
5015 context, $fp could refer to either $sp or the current frame's base
5016 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5017 The GNU Source-Level Debugger''.
5019 *** Changes in GDB 5.3:
5021 * GNU/Linux shared library multi-threaded performance improved.
5023 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5024 `/proc', in preference to `ptrace' for memory reads. This may result
5025 in an improvement in the start-up time of multi-threaded, shared
5026 library applications when run under GDB. One GDB user writes: ``loads
5027 shared libs like mad''.
5029 * ``gdbserver'' now supports multi-threaded applications on some targets
5031 Support for debugging multi-threaded applications which use
5032 the GNU/Linux LinuxThreads package has been added for
5033 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5034 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5036 * GDB now supports C/C++ preprocessor macros.
5038 GDB now expands preprocessor macro invocations in C/C++ expressions,
5039 and provides various commands for showing macro definitions and how
5042 The new command `macro expand EXPRESSION' expands any macro
5043 invocations in expression, and shows the result.
5045 The new command `show macro MACRO-NAME' shows the definition of the
5046 macro named MACRO-NAME, and where it was defined.
5048 Most compilers don't include information about macros in the debugging
5049 information by default. In GCC 3.1, for example, you need to compile
5050 your program with the options `-gdwarf-2 -g3'. If the macro
5051 information is present in the executable, GDB will read it.
5053 * Multi-arched targets.
5055 DEC Alpha (partial) alpha*-*-*
5056 DEC VAX (partial) vax-*-*
5058 National Semiconductor NS32000 (partial) ns32k-*-*
5059 Motorola 68000 (partial) m68k-*-*
5060 Motorola MCORE mcore-*-*
5064 Fujitsu FRV architecture added by Red Hat frv*-*-*
5067 * New native configurations
5069 Alpha NetBSD alpha*-*-netbsd*
5070 SH NetBSD sh*-*-netbsdelf*
5071 MIPS NetBSD mips*-*-netbsd*
5072 UltraSPARC NetBSD sparc64-*-netbsd*
5074 * OBSOLETE configurations and files
5076 Configurations that have been declared obsolete in this release have
5077 been commented out. Unless there is activity to revive these
5078 configurations, the next release of GDB will have their sources
5079 permanently REMOVED.
5081 Mitsubishi D30V d30v-*-*
5082 OS/9000 i[34]86-*-os9k
5083 IBM AIX PS/2 i[3456]86-*-aix
5084 Fujitsu FR30 fr30-*-elf*
5085 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5086 Argonaut Risc Chip (ARC) arc-*-*
5087 i386 running Mach 3.0 i[3456]86-*-mach3*
5088 i386 running Mach i[3456]86-*-mach*
5089 i386 running OSF/1 i[3456]86-*osf1mk*
5090 HP/Apollo 68k Family m68*-apollo*-sysv*,
5092 m68*-hp-bsd*, m68*-hp-hpux*
5093 I960 with MON960 i960-*-coff
5095 * OBSOLETE languages
5097 CHILL, a Pascal like language used by telecommunications companies.
5099 * REMOVED configurations and files
5101 AMD 29k family via UDI a29k-amd-udi, udi29k
5102 A29K VxWorks a29k-*-vxworks
5103 AMD 29000 embedded, using EBMON a29k-none-none
5104 AMD 29000 embedded with COFF a29k-none-coff
5105 AMD 29000 embedded with a.out a29k-none-aout
5107 testsuite/gdb.hp/gdb.threads-hp/ directory
5109 * New command "set max-user-call-depth <nnn>"
5111 This command allows the user to limit the call depth of user-defined
5112 commands. The default is 1024.
5114 * Changes in FreeBSD/i386 native debugging.
5116 Support for the "generate-core-file" has been added.
5118 * New commands "dump", "append", and "restore".
5120 These commands allow data to be copied from target memory
5121 to a bfd-format or binary file (dump and append), and back
5122 from a file into memory (restore).
5124 * Improved "next/step" support on multi-processor Alpha Tru64.
5126 The previous single-step mechanism could cause unpredictable problems,
5127 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5128 of a software single-step mechanism prevents this.
5130 *** Changes in GDB 5.2.1:
5138 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5139 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5140 Fix, by Joel Brobecker imported from mainline.
5142 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5143 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5144 Fix, by Fred Fish, imported from mainline.
5146 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5147 Surprisingly enough, it works now.
5148 By Michal Ludvig, imported from mainline.
5150 i386 hardware watchpoint support:
5151 avoid misses on second run for some targets.
5152 By Pierre Muller, imported from mainline.
5154 *** Changes in GDB 5.2:
5156 * New command "set trust-readonly-sections on[off]".
5158 This command is a hint that tells gdb that read-only sections
5159 really are read-only (ie. that their contents will not change).
5160 In this mode, gdb will go to the object file rather than the
5161 target to read memory from read-only sections (such as ".text").
5162 This can be a significant performance improvement on some
5163 (notably embedded) targets.
5165 * New command "generate-core-file" (or "gcore").
5167 This new gdb command allows the user to drop a core file of the child
5168 process state at any time. So far it's been implemented only for
5169 GNU/Linux and Solaris, but should be relatively easily ported to other
5170 hosts. Argument is core file name (defaults to core.<pid>).
5172 * New command line option
5174 GDB now accepts --pid or -p followed by a process id.
5176 * Change in command line behavior -- corefiles vs. process ids.
5178 There is a subtle behavior in the way in which GDB handles
5179 command line arguments. The first non-flag argument is always
5180 a program to debug, but the second non-flag argument may either
5181 be a corefile or a process id. Previously, GDB would attempt to
5182 open the second argument as a corefile, and if that failed, would
5183 issue a superfluous error message and then attempt to attach it as
5184 a process. Now, if the second argument begins with a non-digit,
5185 it will be treated as a corefile. If it begins with a digit,
5186 GDB will attempt to attach it as a process, and if no such process
5187 is found, will then attempt to open it as a corefile.
5189 * Changes in ARM configurations.
5191 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5192 configuration is fully multi-arch.
5194 * New native configurations
5196 ARM NetBSD arm*-*-netbsd*
5197 x86 OpenBSD i[3456]86-*-openbsd*
5198 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5199 Sparc64 running FreeBSD sparc64-*-freebsd*
5203 Sanyo XStormy16 xstormy16-elf
5205 * OBSOLETE configurations and files
5207 Configurations that have been declared obsolete in this release have
5208 been commented out. Unless there is activity to revive these
5209 configurations, the next release of GDB will have their sources
5210 permanently REMOVED.
5212 AMD 29k family via UDI a29k-amd-udi, udi29k
5213 A29K VxWorks a29k-*-vxworks
5214 AMD 29000 embedded, using EBMON a29k-none-none
5215 AMD 29000 embedded with COFF a29k-none-coff
5216 AMD 29000 embedded with a.out a29k-none-aout
5218 testsuite/gdb.hp/gdb.threads-hp/ directory
5220 * REMOVED configurations and files
5222 TI TMS320C80 tic80-*-*
5224 PowerPC Solaris powerpcle-*-solaris*
5225 PowerPC Windows NT powerpcle-*-cygwin32
5226 PowerPC Netware powerpc-*-netware*
5227 Harris/CXUX m88k m88*-harris-cxux*
5228 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5229 ns32k-utek-sysv* ns32k-utek-*
5230 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5231 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5232 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5233 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5234 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5236 * Changes to command line processing
5238 The new `--args' feature can be used to specify command-line arguments
5239 for the inferior from gdb's command line.
5241 * Changes to key bindings
5243 There is a new `operate-and-get-next' function bound to `C-o'.
5245 *** Changes in GDB 5.1.1
5247 Fix compile problem on DJGPP.
5249 Fix a problem with floating-point registers on the i386 being
5252 Fix to stop GDB crashing on .debug_str debug info.
5254 Numerous documentation fixes.
5256 Numerous testsuite fixes.
5258 *** Changes in GDB 5.1:
5260 * New native configurations
5262 Alpha FreeBSD alpha*-*-freebsd*
5263 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5264 MIPS GNU/Linux mips*-*-linux*
5265 MIPS SGI Irix 6.x mips*-sgi-irix6*
5266 ia64 AIX ia64-*-aix*
5267 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5271 Motorola 68HC11 and 68HC12 m68hc11-elf
5273 UltraSparc running GNU/Linux sparc64-*-linux*
5275 * OBSOLETE configurations and files
5277 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5278 Harris/CXUX m88k m88*-harris-cxux*
5279 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5280 ns32k-utek-sysv* ns32k-utek-*
5281 TI TMS320C80 tic80-*-*
5283 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5284 PowerPC Solaris powerpcle-*-solaris*
5285 PowerPC Windows NT powerpcle-*-cygwin32
5286 PowerPC Netware powerpc-*-netware*
5287 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5288 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5289 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5290 Apple Macintosh (MPW) host N/A
5292 stuff.c (Program to stuff files into a specially prepared space in kdb)
5293 kdb-start.c (Main loop for the standalone kernel debugger)
5295 Configurations that have been declared obsolete in this release have
5296 been commented out. Unless there is activity to revive these
5297 configurations, the next release of GDB will have their sources
5298 permanently REMOVED.
5300 * REMOVED configurations and files
5302 Altos 3068 m68*-altos-*
5303 Convex c1-*-*, c2-*-*
5305 ARM RISCix arm-*-* (as host)
5309 * GDB has been converted to ISO C.
5311 GDB's source code has been converted to ISO C. In particular, the
5312 sources are fully protoized, and rely on standard headers being
5317 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5319 * The MI enabled by default.
5321 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5322 revised and enabled by default. Packages which use GDB as a debugging
5323 engine behind a UI or another front end are encouraged to switch to
5324 using the GDB/MI interface, instead of the old annotations interface
5325 which is now deprecated.
5327 * Support for debugging Pascal programs.
5329 GDB now includes support for debugging Pascal programs. The following
5330 main features are supported:
5332 - Pascal-specific data types such as sets;
5334 - automatic recognition of Pascal sources based on file-name
5337 - Pascal-style display of data types, variables, and functions;
5339 - a Pascal expression parser.
5341 However, some important features are not yet supported.
5343 - Pascal string operations are not supported at all;
5345 - there are some problems with boolean types;
5347 - Pascal type hexadecimal constants are not supported
5348 because they conflict with the internal variables format;
5350 - support for Pascal objects and classes is not full yet;
5352 - unlike Pascal, GDB is case-sensitive for symbol names.
5354 * Changes in completion.
5356 Commands such as `shell', `run' and `set args', which pass arguments
5357 to inferior programs, now complete on file names, similar to what
5358 users expect at the shell prompt.
5360 Commands which accept locations, such as `disassemble', `print',
5361 `breakpoint', `until', etc. now complete on filenames as well as
5362 program symbols. Thus, if you type "break foob TAB", and the source
5363 files linked into the programs include `foobar.c', that file name will
5364 be one of the candidates for completion. However, file names are not
5365 considered for completion after you typed a colon that delimits a file
5366 name from a name of a function in that file, as in "break foo.c:bar".
5368 `set demangle-style' completes on available demangling styles.
5370 * New platform-independent commands:
5372 It is now possible to define a post-hook for a command as well as a
5373 hook that runs before the command. For more details, see the
5374 documentation of `hookpost' in the GDB manual.
5376 * Changes in GNU/Linux native debugging.
5378 Support for debugging multi-threaded programs has been completely
5379 revised for all platforms except m68k and sparc. You can now debug as
5380 many threads as your system allows you to have.
5382 Attach/detach is supported for multi-threaded programs.
5384 Support for SSE registers was added for x86. This doesn't work for
5385 multi-threaded programs though.
5387 * Changes in MIPS configurations.
5389 Multi-arch support is enabled for all MIPS configurations.
5391 GDB can now be built as native debugger on SGI Irix 6.x systems for
5392 debugging n32 executables. (Debugging 64-bit executables is not yet
5395 * Unified support for hardware watchpoints in all x86 configurations.
5397 Most (if not all) native x86 configurations support hardware-assisted
5398 breakpoints and watchpoints in a unified manner. This support
5399 implements debug register sharing between watchpoints, which allows to
5400 put a virtually infinite number of watchpoints on the same address,
5401 and also supports watching regions up to 16 bytes with several debug
5404 The new maintenance command `maintenance show-debug-regs' toggles
5405 debugging print-outs in functions that insert, remove, and test
5406 watchpoints and hardware breakpoints.
5408 * Changes in the DJGPP native configuration.
5410 New command ``info dos sysinfo'' displays assorted information about
5411 the CPU, OS, memory, and DPMI server.
5413 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5414 display information about segment descriptors stored in GDT, LDT, and
5417 New commands ``info dos pde'' and ``info dos pte'' display entries
5418 from Page Directory and Page Tables (for now works with CWSDPMI only).
5419 New command ``info dos address-pte'' displays the Page Table entry for
5420 a given linear address.
5422 GDB can now pass command lines longer than 126 characters to the
5423 program being debugged (requires an update to the libdbg.a library
5424 which is part of the DJGPP development kit).
5426 DWARF2 debug info is now supported.
5428 It is now possible to `step' and `next' through calls to `longjmp'.
5430 * Changes in documentation.
5432 All GDB documentation was converted to GFDL, the GNU Free
5433 Documentation License.
5435 Tracepoints-related commands are now fully documented in the GDB
5438 TUI, the Text-mode User Interface, is now documented in the manual.
5440 Tracepoints-related commands are now fully documented in the GDB
5443 The "GDB Internals" manual now has an index. It also includes
5444 documentation of `ui_out' functions, GDB coding standards, x86
5445 hardware watchpoints, and memory region attributes.
5447 * GDB's version number moved to ``version.in''
5449 The Makefile variable VERSION has been replaced by the file
5450 ``version.in''. People creating GDB distributions should update the
5451 contents of this file.
5455 GUD support is now a standard part of the EMACS distribution.
5457 *** Changes in GDB 5.0:
5459 * Improved support for debugging FP programs on x86 targets
5461 Unified and much-improved support for debugging floating-point
5462 programs on all x86 targets. In particular, ``info float'' now
5463 displays the FP registers in the same format on all x86 targets, with
5464 greater level of detail.
5466 * Improvements and bugfixes in hardware-assisted watchpoints
5468 It is now possible to watch array elements, struct members, and
5469 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5470 on x86 targets no longer erroneously trigger when the address is
5473 * Improvements in the native DJGPP version of GDB
5475 The distribution now includes all the scripts and auxiliary files
5476 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5477 machines ``out of the box''.
5479 The DJGPP version can now debug programs that use signals. It is
5480 possible to catch signals that happened in the debuggee, deliver
5481 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5482 would kill the program being debugged.) Programs that hook hardware
5483 interrupts (keyboard, timer, etc.) can also be debugged.
5485 It is now possible to debug DJGPP programs that redirect their
5486 standard handles or switch them to raw (as opposed to cooked) mode, or
5487 even close them. The command ``run < foo > bar'' works as expected,
5488 and ``info terminal'' reports useful information about the debuggee's
5489 terminal, including raw/cooked mode, redirection, etc.
5491 The DJGPP version now uses termios functions for console I/O, which
5492 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5495 DOS-style file names with drive letters are now fully supported by
5498 It is now possible to debug DJGPP programs that switch their working
5499 directory. It is also possible to rerun the debuggee any number of
5500 times without restarting GDB; thus, you can use the same setup,
5501 breakpoints, etc. for many debugging sessions.
5503 * New native configurations
5505 ARM GNU/Linux arm*-*-linux*
5506 PowerPC GNU/Linux powerpc-*-linux*
5510 Motorola MCore mcore-*-*
5511 x86 VxWorks i[3456]86-*-vxworks*
5512 PowerPC VxWorks powerpc-*-vxworks*
5513 TI TMS320C80 tic80-*-*
5515 * OBSOLETE configurations
5517 Altos 3068 m68*-altos-*
5518 Convex c1-*-*, c2-*-*
5520 ARM RISCix arm-*-* (as host)
5523 Configurations that have been declared obsolete will be commented out,
5524 but the code will be left in place. If there is no activity to revive
5525 these configurations before the next release of GDB, the sources will
5526 be permanently REMOVED.
5528 * Gould support removed
5530 Support for the Gould PowerNode and NP1 has been removed.
5532 * New features for SVR4
5534 On SVR4 native platforms (such as Solaris), if you attach to a process
5535 without first loading a symbol file, GDB will now attempt to locate and
5536 load symbols from the running process's executable file.
5538 * Many C++ enhancements
5540 C++ support has been greatly improved. Overload resolution now works properly
5541 in almost all cases. RTTI support is on the way.
5543 * Remote targets can connect to a sub-program
5545 A popen(3) style serial-device has been added. This device starts a
5546 sub-process (such as a stand-alone simulator) and then communicates
5547 with that. The sub-program to run is specified using the syntax
5548 ``|<program> <args>'' vis:
5550 (gdb) set remotedebug 1
5551 (gdb) target extended-remote |mn10300-elf-sim program-args
5553 * MIPS 64 remote protocol
5555 A long standing bug in the mips64 remote protocol where by GDB
5556 expected certain 32 bit registers (ex SR) to be transfered as 32
5557 instead of 64 bits has been fixed.
5559 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5560 added to provide backward compatibility with older versions of GDB.
5562 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5564 The command ``set remotebinarydownload'' command has been replaced by
5565 ``set remote X-packet''. Other commands in ``set remote'' family
5566 include ``set remote P-packet''.
5568 * Breakpoint commands accept ranges.
5570 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5571 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5572 ``tracepoint passcount'' also accepts a range of tracepoints.
5574 * ``apropos'' command added.
5576 The ``apropos'' command searches through command names and
5577 documentation strings, printing out matches, making it much easier to
5578 try to find a command that does what you are looking for.
5582 A new machine oriented interface (MI) has been added to GDB. This
5583 interface is designed for debug environments running GDB as a separate
5584 process. This is part of the long term libGDB project. See the
5585 "GDB/MI" chapter of the GDB manual for further information. It can be
5586 enabled by configuring with:
5588 .../configure --enable-gdbmi
5590 *** Changes in GDB-4.18:
5592 * New native configurations
5594 HP-UX 10.20 hppa*-*-hpux10.20
5595 HP-UX 11.x hppa*-*-hpux11.0*
5596 M68K GNU/Linux m68*-*-linux*
5600 Fujitsu FR30 fr30-*-elf*
5601 Intel StrongARM strongarm-*-*
5602 Mitsubishi D30V d30v-*-*
5604 * OBSOLETE configurations
5606 Gould PowerNode, NP1 np1-*-*, pn-*-*
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.
5615 As a compatibility experiment, GDB's source files buildsym.h and
5616 buildsym.c have been converted to pure standard C, no longer
5617 containing any K&R compatibility code. We believe that all systems in
5618 use today either come with a standard C compiler, or have a GCC port
5619 available. If this is not true, please report the affected
5620 configuration to bug-gdb@gnu.org immediately. See the README file for
5621 information about getting a standard C compiler if you don't have one
5626 GDB now uses readline 2.2.
5628 * set extension-language
5630 You can now control the mapping between filename extensions and source
5631 languages by using the `set extension-language' command. For instance,
5632 you can ask GDB to treat .c files as C++ by saying
5633 set extension-language .c c++
5634 The command `info extensions' lists all of the recognized extensions
5635 and their associated languages.
5637 * Setting processor type for PowerPC and RS/6000
5639 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5640 you can use the `set processor' command to specify what variant of the
5641 PowerPC family you are debugging. The command
5645 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5646 following PowerPC and RS6000 variants:
5648 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5649 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5651 403GC IBM PowerPC 403GC
5652 505 Motorola PowerPC 505
5653 860 Motorola PowerPC 860 or 850
5654 601 Motorola PowerPC 601
5655 602 Motorola PowerPC 602
5656 603 Motorola/IBM PowerPC 603 or 603e
5657 604 Motorola PowerPC 604 or 604e
5658 750 Motorola/IBM PowerPC 750 or 750
5660 At the moment, this command just tells GDB what to name the
5661 special-purpose processor registers. Since almost all the affected
5662 registers are inaccessible to user-level programs, this command is
5663 only useful for remote debugging in its present form.
5667 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5668 more extensive support for HP-UX. Added features include shared
5669 library support, kernel threads and hardware watchpoints for 11.00,
5670 support for HP's ANSI C and C++ compilers, and a compatibility mode
5671 for xdb and dbx commands.
5675 HP's donation includes the new concept of catchpoints, which is a
5676 generalization of the old catch command. On HP-UX, it is now possible
5677 to catch exec, fork, and vfork, as well as library loading.
5679 This means that the existing catch command has changed; its first
5680 argument now specifies the type of catch to be set up. See the
5681 output of "help catch" for a list of catchpoint types.
5683 * Debugging across forks
5685 On HP-UX, you can choose which process to debug when a fork() happens
5690 HP has donated a curses-based terminal user interface (TUI). To get
5691 it, build with --enable-tui. Although this can be enabled for any
5692 configuration, at present it only works for native HP debugging.
5694 * GDB remote protocol additions
5696 A new protocol packet 'X' that writes binary data is now available.
5697 Default behavior is to try 'X', then drop back to 'M' if the stub
5698 fails to respond. The settable variable `remotebinarydownload'
5699 allows explicit control over the use of 'X'.
5701 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5702 full 64-bit address. The command
5704 set remoteaddresssize 32
5706 can be used to revert to the old behaviour. For existing remote stubs
5707 the change should not be noticed, as the additional address information
5710 In order to assist in debugging stubs, you may use the maintenance
5711 command `packet' to send any text string to the stub. For instance,
5713 maint packet heythere
5715 sends the packet "$heythere#<checksum>". Note that it is very easy to
5716 disrupt a debugging session by sending the wrong packet at the wrong
5719 The compare-sections command allows you to compare section data on the
5720 target to what is in the executable file without uploading or
5721 downloading, by comparing CRC checksums.
5723 * Tracing can collect general expressions
5725 You may now collect general expressions at tracepoints. This requires
5726 further additions to the target-side stub; see tracepoint.c and
5727 doc/agentexpr.texi for further details.
5729 * mask-address variable for Mips
5731 For Mips targets, you may control the zeroing of the upper 32 bits of
5732 a 64-bit address by entering `set mask-address on'. This is mainly
5733 of interest to users of embedded R4xxx and R5xxx processors.
5735 * Higher serial baud rates
5737 GDB's serial code now allows you to specify baud rates 57600, 115200,
5738 230400, and 460800 baud. (Note that your host system may not be able
5739 to achieve all of these rates.)
5743 The i960 configuration now includes an initial implementation of a
5744 builtin simulator, contributed by Jim Wilson.
5747 *** Changes in GDB-4.17:
5749 * New native configurations
5751 Alpha GNU/Linux alpha*-*-linux*
5752 Unixware 2.x i[3456]86-unixware2*
5753 Irix 6.x mips*-sgi-irix6*
5754 PowerPC GNU/Linux powerpc-*-linux*
5755 PowerPC Solaris powerpcle-*-solaris*
5756 Sparc GNU/Linux sparc-*-linux*
5757 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5761 Argonaut Risc Chip (ARC) arc-*-*
5762 Hitachi H8/300S h8300*-*-*
5763 Matsushita MN10200 w/simulator mn10200-*-*
5764 Matsushita MN10300 w/simulator mn10300-*-*
5765 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5766 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5767 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5768 Mitsubishi D10V w/simulator d10v-*-*
5769 Mitsubishi M32R/D w/simulator m32r-*-elf*
5770 Tsqware Sparclet sparclet-*-*
5771 NEC V850 w/simulator v850-*-*
5773 * New debugging protocols
5775 ARM with RDI protocol arm*-*-*
5776 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5777 DDB and LSI variants of PMON protocol mips*-*-*
5778 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5779 PowerPC with SDS protocol powerpc{,le}-*-eabi
5780 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5784 All configurations can now understand and use the DWARF 2 debugging
5785 format. The choice is automatic, if the symbol file contains DWARF 2
5790 GDB now includes basic Java language support. This support is
5791 only useful with Java compilers that produce native machine code.
5793 * solib-absolute-prefix and solib-search-path
5795 For SunOS and SVR4 shared libraries, you may now set the prefix for
5796 loading absolute shared library symbol files, and the search path for
5797 locating non-absolute shared library symbol files.
5799 * Live range splitting
5801 GDB can now effectively debug code for which GCC has performed live
5802 range splitting as part of its optimization. See gdb/doc/LRS for
5803 more details on the expected format of the stabs information.
5807 GDB's support for the GNU Hurd, including thread debugging, has been
5808 updated to work with current versions of the Hurd.
5812 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5813 instruction set. ARM GDB automatically detects when Thumb
5814 instructions are in use, and adjusts disassembly and backtracing
5819 GDB's MIPS target configurations now handle the MIP16 16-bit
5824 GDB now includes support for overlays; if an executable has been
5825 linked such that multiple sections are based at the same address, GDB
5826 will decide which section to use for symbolic info. You can choose to
5827 control the decision manually, using overlay commands, or implement
5828 additional target-side support and use "overlay load-target" to bring
5829 in the overlay mapping. Do "help overlay" for more detail.
5833 The command "info symbol <address>" displays information about
5834 the symbol at the specified address.
5838 The standard remote protocol now includes an extension that allows
5839 asynchronous collection and display of trace data. This requires
5840 extensive support in the target-side debugging stub. Tracing mode
5841 includes a new interaction mode in GDB and new commands: see the
5842 file tracepoint.c for more details.
5846 Configurations for embedded MIPS now include a simulator contributed
5847 by Cygnus Solutions. The simulator supports the instruction sets
5848 of most MIPS variants.
5852 Sparc configurations may now include the ERC32 simulator contributed
5853 by the European Space Agency. The simulator is not built into
5854 Sparc targets by default; configure with --enable-sim to include it.
5858 For target configurations that may include multiple variants of a
5859 basic architecture (such as MIPS and SH), you may now set the
5860 architecture explicitly. "set arch" sets, "info arch" lists
5861 the possible architectures.
5863 *** Changes in GDB-4.16:
5865 * New native configurations
5867 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5868 M68K NetBSD m68k-*-netbsd*
5869 PowerPC AIX 4.x powerpc-*-aix*
5870 PowerPC MacOS powerpc-*-macos*
5871 PowerPC Windows NT powerpcle-*-cygwin32
5872 RS/6000 AIX 4.x rs6000-*-aix4*
5876 ARM with RDP protocol arm-*-*
5877 I960 with MON960 i960-*-coff
5878 MIPS VxWorks mips*-*-vxworks*
5879 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5880 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5882 Matra Sparclet sparclet-*-*
5886 The powerpc-eabi configuration now includes the PSIM simulator,
5887 contributed by Andrew Cagney, with assistance from Mike Meissner.
5888 PSIM is a very elaborate model of the PowerPC, including not only
5889 basic instruction set execution, but also details of execution unit
5890 performance and I/O hardware. See sim/ppc/README for more details.
5894 GDB now works with Solaris 2.5.
5896 * Windows 95/NT native
5898 GDB will now work as a native debugger on Windows 95 and Windows NT.
5899 To build it from source, you must use the "gnu-win32" environment,
5900 which uses a DLL to emulate enough of Unix to run the GNU tools.
5901 Further information, binaries, and sources are available at
5902 ftp.cygnus.com, under pub/gnu-win32.
5904 * dont-repeat command
5906 If a user-defined command includes the command `dont-repeat', then the
5907 command will not be repeated if the user just types return. This is
5908 useful if the command is time-consuming to run, so that accidental
5909 extra keystrokes don't run the same command many times.
5911 * Send break instead of ^C
5913 The standard remote protocol now includes an option to send a break
5914 rather than a ^C to the target in order to interrupt it. By default,
5915 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5917 * Remote protocol timeout
5919 The standard remote protocol includes a new variable `remotetimeout'
5920 that allows you to set the number of seconds before GDB gives up trying
5921 to read from the target. The default value is 2.
5923 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5925 By default GDB will automatically keep track of objects as they are
5926 loaded and unloaded by the dynamic linker. By using the command `set
5927 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5928 when shared library events occur, thus allowing you to set breakpoints
5929 in shared libraries which are explicitly loaded by the inferior.
5931 Note this feature does not work on hpux8. On hpux9 you must link
5932 /usr/lib/end.o into your program. This feature should work
5933 automatically on hpux10.
5935 * Irix 5.x hardware watchpoint support
5937 Irix 5 configurations now support the use of hardware watchpoints.
5939 * Mips protocol "SYN garbage limit"
5941 When debugging a Mips target using the `target mips' protocol, you
5942 may set the number of characters that GDB will ignore by setting
5943 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5944 every character. The default value is 1050.
5946 * Recording and replaying remote debug sessions
5948 If you set `remotelogfile' to the name of a file, gdb will write to it
5949 a recording of a remote debug session. This recording may then be
5950 replayed back to gdb using "gdbreplay". See gdbserver/README for
5951 details. This is useful when you have a problem with GDB while doing
5952 remote debugging; you can make a recording of the session and send it
5953 to someone else, who can then recreate the problem.
5955 * Speedups for remote debugging
5957 GDB includes speedups for downloading and stepping MIPS systems using
5958 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5959 and more efficient S-record downloading.
5961 * Memory use reductions and statistics collection
5963 GDB now uses less memory and reports statistics about memory usage.
5964 Try the `maint print statistics' command, for example.
5966 *** Changes in GDB-4.15:
5968 * Psymtabs for XCOFF
5970 The symbol reader for AIX GDB now uses partial symbol tables. This
5971 can greatly improve startup time, especially for large executables.
5973 * Remote targets use caching
5975 Remote targets now use a data cache to speed up communication with the
5976 remote side. The data cache could lead to incorrect results because
5977 it doesn't know about volatile variables, thus making it impossible to
5978 debug targets which use memory mapped I/O devices. `set remotecache
5979 off' turns the the data cache off.
5981 * Remote targets may have threads
5983 The standard remote protocol now includes support for multiple threads
5984 in the target system, using new protocol commands 'H' and 'T'. See
5985 gdb/remote.c for details.
5989 If GDB is configured with `--enable-netrom', then it will include
5990 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5991 acts as though it is a bank of ROM on the target board, but you can
5992 write into it over the network. GDB's support consists only of
5993 support for fast loading into the emulated ROM; to debug, you must use
5994 another protocol, such as standard remote protocol. The usual
5995 sequence is something like
5997 target nrom <netrom-hostname>
5999 target remote <netrom-hostname>:1235
6003 GDB now includes support for the Apple Macintosh, as a host only. It
6004 may be run as either an MPW tool or as a standalone application, and
6005 it can debug through the serial port. All the usual GDB commands are
6006 available, but to the target command, you must supply "serial" as the
6007 device type instead of "/dev/ttyXX". See mpw-README in the main
6008 directory for more information on how to build. The MPW configuration
6009 scripts */mpw-config.in support only a few targets, and only the
6010 mips-idt-ecoff target has been tested.
6014 GDB configuration now uses autoconf. This is not user-visible,
6015 but does simplify configuration and building.
6019 GDB now supports hpux10.
6021 *** Changes in GDB-4.14:
6023 * New native configurations
6025 x86 FreeBSD i[345]86-*-freebsd
6026 x86 NetBSD i[345]86-*-netbsd
6027 NS32k NetBSD ns32k-*-netbsd
6028 Sparc NetBSD sparc-*-netbsd
6032 A29K VxWorks a29k-*-vxworks
6033 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6034 CPU32 EST-300 emulator m68*-*-est*
6035 PowerPC ELF powerpc-*-elf
6038 * Alpha OSF/1 support for procfs
6040 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6041 possible to attach to running processes. As the mounting of the /proc
6042 filesystem is optional on the Alpha, GDB automatically determines
6043 the availability of /proc during startup. This can lead to problems
6044 if /proc is unmounted after GDB has been started.
6046 * Arguments to user-defined commands
6048 User commands may accept up to 10 arguments separated by whitespace.
6049 Arguments are accessed within the user command via $arg0..$arg9. A
6052 print $arg0 + $arg1 + $arg2
6054 To execute the command use:
6057 Defines the command "adder" which prints the sum of its three arguments.
6058 Note the arguments are text substitutions, so they may reference variables,
6059 use complex expressions, or even perform inferior function calls.
6061 * New `if' and `while' commands
6063 This makes it possible to write more sophisticated user-defined
6064 commands. Both commands take a single argument, which is the
6065 expression to evaluate, and must be followed by the commands to
6066 execute, one per line, if the expression is nonzero, the list being
6067 terminated by the word `end'. The `if' command list may include an
6068 `else' word, which causes the following commands to be executed only
6069 if the expression is zero.
6071 * Fortran source language mode
6073 GDB now includes partial support for Fortran 77. It will recognize
6074 Fortran programs and can evaluate a subset of Fortran expressions, but
6075 variables and functions may not be handled correctly. GDB will work
6076 with G77, but does not yet know much about symbols emitted by other
6079 * Better HPUX support
6081 Most debugging facilities now work on dynamic executables for HPPAs
6082 running hpux9 or later. You can attach to running dynamically linked
6083 processes, but by default the dynamic libraries will be read-only, so
6084 for instance you won't be able to put breakpoints in them. To change
6085 that behavior do the following before running the program:
6091 This will cause the libraries to be mapped private and read-write.
6092 To revert to the normal behavior, do this:
6098 You cannot set breakpoints or examine data in the library until after
6099 the library is loaded if the function/data symbols do not have
6102 GDB can now also read debug symbols produced by the HP C compiler on
6103 HPPAs (sorry, no C++, Fortran or 68k support).
6105 * Target byte order now dynamically selectable
6107 You can choose which byte order to use with a target system, via the
6108 commands "set endian big" and "set endian little", and you can see the
6109 current setting by using "show endian". You can also give the command
6110 "set endian auto", in which case GDB will use the byte order
6111 associated with the executable. Currently, only embedded MIPS
6112 configurations support dynamic selection of target byte order.
6114 * New DOS host serial code
6116 This version uses DPMI interrupts to handle buffered I/O, so you
6117 no longer need to run asynctsr when debugging boards connected to
6120 *** Changes in GDB-4.13:
6122 * New "complete" command
6124 This lists all the possible completions for the rest of the line, if it
6125 were to be given as a command itself. This is intended for use by emacs.
6127 * Trailing space optional in prompt
6129 "set prompt" no longer adds a space for you after the prompt you set. This
6130 allows you to set a prompt which ends in a space or one that does not.
6132 * Breakpoint hit counts
6134 "info break" now displays a count of the number of times the breakpoint
6135 has been hit. This is especially useful in conjunction with "ignore"; you
6136 can ignore a large number of breakpoint hits, look at the breakpoint info
6137 to see how many times the breakpoint was hit, then run again, ignoring one
6138 less than that number, and this will get you quickly to the last hit of
6141 * Ability to stop printing at NULL character
6143 "set print null-stop" will cause GDB to stop printing the characters of
6144 an array when the first NULL is encountered. This is useful when large
6145 arrays actually contain only short strings.
6147 * Shared library breakpoints
6149 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6150 breakpoints in shared libraries before the executable is run.
6152 * Hardware watchpoints
6154 There is a new hardware breakpoint for the watch command for sparclite
6155 targets. See gdb/sparclite/hw_breakpoint.note.
6157 Hardware watchpoints are also now supported under GNU/Linux.
6161 Annotations have been added. These are for use with graphical interfaces,
6162 and are still experimental. Currently only gdba.el uses these.
6164 * Improved Irix 5 support
6166 GDB now works properly with Irix 5.2.
6168 * Improved HPPA support
6170 GDB now works properly with the latest GCC and GAS.
6172 * New native configurations
6174 Sequent PTX4 i[34]86-sequent-ptx4
6175 HPPA running OSF/1 hppa*-*-osf*
6176 Atari TT running SVR4 m68*-*-sysv4*
6177 RS/6000 LynxOS rs6000-*-lynxos*
6181 OS/9000 i[34]86-*-os9k
6182 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6185 * Hitachi SH7000 and E7000-PC ICE support
6187 There is now support for communicating with the Hitachi E7000-PC ICE.
6188 This is available automatically when GDB is configured for the SH.
6192 As usual, a variety of small fixes and improvements, both generic
6193 and configuration-specific. See the ChangeLog for more detail.
6195 *** Changes in GDB-4.12:
6197 * Irix 5 is now supported
6201 GDB-4.12 on the HPPA has a number of changes which make it unable
6202 to debug the output from the currently released versions of GCC and
6203 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6204 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6205 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6208 *** Changes in GDB-4.11:
6210 * User visible changes:
6214 The "set remotedebug" option is now consistent between the mips remote
6215 target, remote targets using the gdb-specific protocol, UDI (AMD's
6216 debug protocol for the 29k) and the 88k bug monitor. It is now an
6217 integer specifying a debug level (normally 0 or 1, but 2 means more
6218 debugging info for the mips target).
6220 * DEC Alpha native support
6222 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6223 debug info, but GDB works fairly well with the DEC compiler and should
6224 work with a future GCC release. See the README file for a few
6225 Alpha-specific notes.
6227 * Preliminary thread implementation
6229 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6231 * LynxOS native and target support for 386
6233 This release has been hosted on LynxOS 2.2, and also can be configured
6234 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6237 * Improvements in C++ mangling/demangling.
6239 This release has much better g++ debugging, specifically in name
6240 mangling/demangling, virtual function calls, print virtual table,
6241 call methods, ...etc.
6243 *** Changes in GDB-4.10:
6245 * User visible changes:
6247 Remote debugging using the GDB-specific (`target remote') protocol now
6248 supports the `load' command. This is only useful if you have some
6249 other way of getting the stub to the target system, and you can put it
6250 somewhere in memory where it won't get clobbered by the download.
6252 Filename completion now works.
6254 When run under emacs mode, the "info line" command now causes the
6255 arrow to point to the line specified. Also, "info line" prints
6256 addresses in symbolic form (as well as hex).
6258 All vxworks based targets now support a user settable option, called
6259 vxworks-timeout. This option represents the number of seconds gdb
6260 should wait for responses to rpc's. You might want to use this if
6261 your vxworks target is, perhaps, a slow software simulator or happens
6262 to be on the far side of a thin network line.
6266 This release contains support for using a DEC alpha as a GDB host for
6267 cross debugging. Native alpha debugging is not supported yet.
6270 *** Changes in GDB-4.9:
6274 This is the first GDB release which is accompanied by a matching testsuite.
6275 The testsuite requires installation of dejagnu, which should be available
6276 via ftp from most sites that carry GNU software.
6280 'Cfront' style demangling has had its name changed to 'ARM' style, to
6281 emphasize that it was written from the specifications in the C++ Annotated
6282 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6283 disclaimers, it still generated too much confusion with users attempting to
6284 use gdb with AT&T cfront.
6288 GDB now uses a standard remote interface to a simulator library.
6289 So far, the library contains simulators for the Zilog Z8001/2, the
6290 Hitachi H8/300, H8/500 and Super-H.
6292 * New targets supported
6294 H8/300 simulator h8300-hitachi-hms or h8300hms
6295 H8/500 simulator h8500-hitachi-hms or h8500hms
6296 SH simulator sh-hitachi-hms or sh
6297 Z8000 simulator z8k-zilog-none or z8ksim
6298 IDT MIPS board over serial line mips-idt-ecoff
6300 Cross-debugging to GO32 targets is supported. It requires a custom
6301 version of the i386-stub.c module which is integrated with the
6302 GO32 memory extender.
6304 * New remote protocols
6306 MIPS remote debugging protocol.
6308 * New source languages supported
6310 This version includes preliminary support for Chill, a Pascal like language
6311 used by telecommunications companies. Chill support is also being integrated
6312 into the GNU compiler, but we don't know when it will be publically available.
6315 *** Changes in GDB-4.8:
6317 * HP Precision Architecture supported
6319 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6320 version of this support was available as a set of patches from the
6321 University of Utah. GDB does not support debugging of programs
6322 compiled with the HP compiler, because HP will not document their file
6323 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6324 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6326 Many problems in the preliminary version have been fixed.
6328 * Faster and better demangling
6330 We have improved template demangling and fixed numerous bugs in the GNU style
6331 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6332 character types (wchar_t) are now supported. Demangling of each symbol is now
6333 only done once, and is cached when the symbol table for a file is read in.
6334 This results in a small increase in memory usage for C programs, a moderate
6335 increase in memory usage for C++ programs, and a fantastic speedup in
6338 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6339 from the specifications in the Annotated Reference Manual, which AT&T's
6340 compiler does not actually implement.
6342 * G++ multiple inheritance compiler problem
6344 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6345 inheritance lattices was reworked to properly discover ambiguities. We
6346 recently found an example which causes this new algorithm to fail in a
6347 very subtle way, producing bad debug information for those classes.
6348 The file 'gcc.patch' (in this directory) can be applied to gcc to
6349 circumvent the problem. A future GCC release will contain a complete
6352 The previous G++ debug info problem (mentioned below for the gdb-4.7
6353 release) is fixed in gcc version 2.3.2.
6355 * Improved configure script
6357 The `configure' script will now attempt to guess your system type if
6358 you don't supply a host system type. The old scheme of supplying a
6359 host system triplet is preferable over using this. All the magic is
6360 done in the new `config.guess' script. Examine it for details.
6362 We have also brought our configure script much more in line with the FSF's
6363 version. It now supports the --with-xxx options. In particular,
6364 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6365 The resulting GDB will not be able to read arbitrary object file formats --
6366 only the format ``expected'' to be used on the configured target system.
6367 We hope to make this the default in a future release.
6369 * Documentation improvements
6371 There's new internal documentation on how to modify GDB, and how to
6372 produce clean changes to the code. We implore people to read it
6373 before submitting changes.
6375 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6376 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6377 `info' files are also provided. To build `info' files from scratch,
6378 you will need the latest `makeinfo' release, which will be available in
6379 a future texinfo-X.Y release.
6381 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6382 We're not sure exactly which versions have this problem, but it has
6383 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6384 or better. If that isn't possible, there is a patch in
6385 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6386 around this problem.
6390 GDB now supports array constants that can be used in expressions typed in by
6391 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6392 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6395 The new directory `gdb/sparclite' contains a program that demonstrates
6396 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6398 * New native hosts supported
6400 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6401 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6403 * New targets supported
6405 AMD 29k family via UDI a29k-amd-udi or udi29k
6407 * New file formats supported
6409 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6410 HPUX core files, and SCO 3.2v2 core files.
6414 Attaching to processes now works again; thanks for the many bug reports.
6416 We have also stomped on a bunch of core dumps caused by
6417 printf_filtered("%s") problems.
6419 We eliminated a copyright problem on the rpc and ptrace header files
6420 for VxWorks, which was discovered at the last minute during the 4.7
6421 release. You should now be able to build a VxWorks GDB.
6423 You can now interrupt gdb while an attached process is running. This
6424 will cause the attached process to stop, and give control back to GDB.
6426 We fixed problems caused by using too many file descriptors
6427 for reading symbols from object files and libraries. This was
6428 especially a problem for programs that used many (~100) shared
6431 The `step' command now only enters a subroutine if there is line number
6432 information for the subroutine. Otherwise it acts like the `next'
6433 command. Previously, `step' would enter subroutines if there was
6434 any debugging information about the routine. This avoids problems
6435 when using `cc -g1' on MIPS machines.
6437 * Internal improvements
6439 GDB's internal interfaces have been improved to make it easier to support
6440 debugging of multiple languages in the future.
6442 GDB now uses a common structure for symbol information internally.
6443 Minimal symbols (derived from linkage symbols in object files), partial
6444 symbols (from a quick scan of debug information), and full symbols
6445 contain a common subset of information, making it easier to write
6446 shared code that handles any of them.
6448 * New command line options
6450 We now accept --silent as an alias for --quiet.
6454 The memory-mapped-malloc library is now licensed under the GNU Library
6455 General Public License.
6457 *** Changes in GDB-4.7:
6459 * Host/native/target split
6461 GDB has had some major internal surgery to untangle the support for
6462 hosts and remote targets. Now, when you configure GDB for a remote
6463 target, it will no longer load in all of the support for debugging
6464 local programs on the host. When fully completed and tested, this will
6465 ensure that arbitrary host/target combinations are possible.
6467 The primary conceptual shift is to separate the non-portable code in
6468 GDB into three categories. Host specific code is required any time GDB
6469 is compiled on that host, regardless of the target. Target specific
6470 code relates to the peculiarities of the target, but can be compiled on
6471 any host. Native specific code is everything else: it can only be
6472 built when the host and target are the same system. Child process
6473 handling and core file support are two common `native' examples.
6475 GDB's use of /proc for controlling Unix child processes is now cleaner.
6476 It has been split out into a single module under the `target_ops' vector,
6477 plus two native-dependent functions for each system that uses /proc.
6479 * New hosts supported
6481 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6482 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6483 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6485 * New targets supported
6487 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6488 68030 and CPU32 m68030-*-*, m68332-*-*
6490 * New native hosts supported
6492 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6493 (386bsd is not well tested yet)
6494 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6496 * New file formats supported
6498 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6499 supports reading of `a.out.adobe' object files, which are an a.out
6500 format extended with minimal information about multiple sections.
6504 `show copying' is the same as the old `info copying'.
6505 `show warranty' is the same as `info warrantee'.
6506 These were renamed for consistency. The old commands continue to work.
6508 `info handle' is a new alias for `info signals'.
6510 You can now define pre-command hooks, which attach arbitrary command
6511 scripts to any command. The commands in the hook will be executed
6512 prior to the user's command. You can also create a hook which will be
6513 executed whenever the program stops. See gdb.texinfo.
6517 We now deal with Cfront style name mangling, and can even extract type
6518 info from mangled symbols. GDB can automatically figure out which
6519 symbol mangling style your C++ compiler uses.
6521 Calling of methods and virtual functions has been improved as well.
6525 The crash that occured when debugging Sun Ansi-C compiled binaries is
6526 fixed. This was due to mishandling of the extra N_SO stabs output
6529 We also finally got Ultrix 4.2 running in house, and fixed core file
6530 support, with help from a dozen people on the net.
6532 John M. Farrell discovered that the reason that single-stepping was so
6533 slow on all of the Mips based platforms (primarily SGI and DEC) was
6534 that we were trying to demangle and lookup a symbol used for internal
6535 purposes on every instruction that was being stepped through. Changing
6536 the name of that symbol so that it couldn't be mistaken for a C++
6537 mangled symbol sped things up a great deal.
6539 Rich Pixley sped up symbol lookups in general by getting much smarter
6540 about when C++ symbol mangling is necessary. This should make symbol
6541 completion (TAB on the command line) much faster. It's not as fast as
6542 we'd like, but it's significantly faster than gdb-4.6.
6546 A new user controllable variable 'call_scratch_address' can
6547 specify the location of a scratch area to be used when GDB
6548 calls a function in the target. This is necessary because the
6549 usual method of putting the scratch area on the stack does not work
6550 in systems that have separate instruction and data spaces.
6552 We integrated changes to support the 29k UDI (Universal Debugger
6553 Interface), but discovered at the last minute that we didn't have all
6554 of the appropriate copyright paperwork. We are working with AMD to
6555 resolve this, and hope to have it available soon.
6559 We have sped up the remote serial line protocol, especially for targets
6560 with lots of registers. It now supports a new `expedited status' ('T')
6561 message which can be used in place of the existing 'S' status message.
6562 This allows the remote stub to send only the registers that GDB
6563 needs to make a quick decision about single-stepping or conditional
6564 breakpoints, eliminating the need to fetch the entire register set for
6565 each instruction being stepped through.
6567 The GDB remote serial protocol now implements a write-through cache for
6568 registers, only re-reading the registers if the target has run.
6570 There is also a new remote serial stub for SPARC processors. You can
6571 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6572 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6573 processor with a serial port.
6577 Configure.in files have become much easier to read and modify. A new
6578 `table driven' format makes it more obvious what configurations are
6579 supported, and what files each one uses.
6583 There is a new opcodes library which will eventually contain all of the
6584 disassembly routines and opcode tables. At present, it only contains
6585 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6586 disassembler (binutils/objdump) to share these routines.
6588 The libiberty library is now copylefted under the GNU Library General
6589 Public License. This allows more liberal use, and was done so libg++
6590 can use it. This makes no difference to GDB, since the Library License
6591 grants all the rights from the General Public License.
6595 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6596 reference to the stabs symbol info used by the debugger. It is (as far
6597 as we know) the only published document on this fascinating topic. We
6598 encourage you to read it, compare it to the stabs information on your
6599 system, and send improvements on the document in general (to
6600 bug-gdb@prep.ai.mit.edu).
6602 And, of course, many bugs have been fixed.
6605 *** Changes in GDB-4.6:
6607 * Better support for C++ function names
6609 GDB now accepts as input the "demangled form" of C++ overloaded function
6610 names and member function names, and can do command completion on such names
6611 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6612 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6613 Make use of command completion, it is your friend.
6615 GDB also now accepts a variety of C++ mangled symbol formats. They are
6616 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6617 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6618 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6619 for the list of formats.
6621 * G++ symbol mangling problem
6623 Recent versions of gcc have a bug in how they emit debugging information for
6624 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6625 directory) can be applied to gcc to fix the problem. Alternatively, if you
6626 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6627 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6628 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6631 * New 'maintenance' command
6633 All of the commands related to hacking GDB internals have been moved out of
6634 the main command set, and now live behind the 'maintenance' command. This
6635 can also be abbreviated as 'mt'. The following changes were made:
6637 dump-me -> maintenance dump-me
6638 info all-breakpoints -> maintenance info breakpoints
6639 printmsyms -> maintenance print msyms
6640 printobjfiles -> maintenance print objfiles
6641 printpsyms -> maintenance print psymbols
6642 printsyms -> maintenance print symbols
6644 The following commands are new:
6646 maintenance demangle Call internal GDB demangler routine to
6647 demangle a C++ link name and prints the result.
6648 maintenance print type Print a type chain for a given symbol
6650 * Change to .gdbinit file processing
6652 We now read the $HOME/.gdbinit file before processing the argv arguments
6653 (e.g. reading symbol files or core files). This allows global parameters to
6654 be set, which will apply during the symbol reading. The ./.gdbinit is still
6655 read after argv processing.
6657 * New hosts supported
6659 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6661 GNU/Linux support i386-unknown-linux or linux
6663 We are also including code to support the HP/PA running BSD and HPUX. This
6664 is almost guaranteed not to work, as we didn't have time to test or build it
6665 for this release. We are including it so that the more adventurous (or
6666 masochistic) of you can play with it. We also had major problems with the
6667 fact that the compiler that we got from HP doesn't support the -g option.
6670 * New targets supported
6672 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6674 * More smarts about finding #include files
6676 GDB now remembers the compilation directory for all include files, and for
6677 all files from which C is generated (like yacc and lex sources). This
6678 greatly improves GDB's ability to find yacc/lex sources, and include files,
6679 especially if you are debugging your program from a directory different from
6680 the one that contains your sources.
6682 We also fixed a bug which caused difficulty with listing and setting
6683 breakpoints in include files which contain C code. (In the past, you had to
6684 try twice in order to list an include file that you hadn't looked at before.)
6686 * Interesting infernals change
6688 GDB now deals with arbitrary numbers of sections, where the symbols for each
6689 section must be relocated relative to that section's landing place in the
6690 target's address space. This work was needed to support ELF with embedded
6691 stabs used by Solaris-2.0.
6693 * Bug fixes (of course!)
6695 There have been loads of fixes for the following things:
6696 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6697 i960, stabs, DOS(GO32), procfs, etc...
6699 See the ChangeLog for details.
6701 *** Changes in GDB-4.5:
6703 * New machines supported (host and target)
6705 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6707 SGI Irix-4.x mips-sgi-irix4 or iris4
6709 * New malloc package
6711 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6712 Mmalloc is capable of handling mutiple heaps of memory. It is also
6713 capable of saving a heap to a file, and then mapping it back in later.
6714 This can be used to greatly speedup the startup of GDB by using a
6715 pre-parsed symbol table which lives in a mmalloc managed heap. For
6716 more details, please read mmalloc/mmalloc.texi.
6720 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6721 'help info proc' for details.
6723 * MIPS ecoff symbol table format
6725 The code that reads MIPS symbol table format is now supported on all hosts.
6726 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6729 * File name changes for MS-DOS
6731 Many files in the config directories have been renamed to make it easier to
6732 support GDB on MS-DOSe systems (which have very restrictive file name
6733 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6734 environment) is close to working but has some remaining problems. Note
6735 that debugging of DOS programs is not supported, due to limitations
6736 in the ``operating system'', but it can be used to host cross-debugging.
6738 * Cross byte order fixes
6740 Many fixes have been made to support cross debugging of Sparc and MIPS
6741 targets from hosts whose byte order differs.
6743 * New -mapped and -readnow options
6745 If memory-mapped files are available on your system through the 'mmap'
6746 system call, you can use the -mapped option on the `file' or
6747 `symbol-file' commands to cause GDB to write the symbols from your
6748 program into a reusable file. If the program you are debugging is
6749 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6750 Future GDB debugging sessions will notice the presence of this file,
6751 and will quickly map in symbol information from it, rather than reading
6752 the symbol table from the executable program. Using the '-mapped'
6753 option in a GDB `file' or `symbol-file' command has the same effect as
6754 starting GDB with the '-mapped' command-line option.
6756 You can cause GDB to read the entire symbol table immediately by using
6757 the '-readnow' option with any of the commands that load symbol table
6758 information (or on the GDB command line). This makes the command
6759 slower, but makes future operations faster.
6761 The -mapped and -readnow options are typically combined in order to
6762 build a `fred.syms' file that contains complete symbol information.
6763 A simple GDB invocation to do nothing but build a `.syms' file for future
6766 gdb -batch -nx -mapped -readnow programname
6768 The `.syms' file is specific to the host machine on which GDB is run.
6769 It holds an exact image of GDB's internal symbol table. It cannot be
6770 shared across multiple host platforms.
6772 * longjmp() handling
6774 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6775 siglongjmp() without losing control. This feature has not yet been ported to
6776 all systems. It currently works on many 386 platforms, all MIPS-based
6777 platforms (SGI, DECstation, etc), and Sun3/4.
6781 Preliminary work has been put in to support the new Solaris OS from Sun. At
6782 this time, it can control and debug processes, but it is not capable of
6787 As always, many many bug fixes. The major areas were with g++, and mipsread.
6788 People using the MIPS-based platforms should experience fewer mysterious
6789 crashes and trashed symbol tables.
6791 *** Changes in GDB-4.4:
6793 * New machines supported (host and target)
6795 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6797 BSD Reno on Vax vax-dec-bsd
6798 Ultrix on Vax vax-dec-ultrix
6800 * New machines supported (target)
6802 AMD 29000 embedded, using EBMON a29k-none-none
6806 GDB continues to improve its handling of C++. `References' work better.
6807 The demangler has also been improved, and now deals with symbols mangled as
6808 per the Annotated C++ Reference Guide.
6810 GDB also now handles `stabs' symbol information embedded in MIPS
6811 `ecoff' symbol tables. Since the ecoff format was not easily
6812 extensible to handle new languages such as C++, this appeared to be a
6813 good way to put C++ debugging info into MIPS binaries. This option
6814 will be supported in the GNU C compiler, version 2, when it is
6817 * New features for SVR4
6819 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6820 shared libraries. Debugging dynamically linked programs should present
6821 only minor differences from debugging statically linked programs.
6823 The `info proc' command will print out information about any process
6824 on an SVR4 system (including the one you are debugging). At the moment,
6825 it prints the address mappings of the process.
6827 If you bring up GDB on another SVR4 system, please send mail to
6828 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6830 * Better dynamic linking support in SunOS
6832 Reading symbols from shared libraries which contain debugging symbols
6833 now works properly. However, there remain issues such as automatic
6834 skipping of `transfer vector' code during function calls, which
6835 make it harder to debug code in a shared library, than to debug the
6836 same code linked statically.
6840 GDB is now using the latest `getopt' routines from the FSF. This
6841 version accepts the -- prefix for options with long names. GDB will
6842 continue to accept the old forms (-option and +option) as well.
6843 Various single letter abbreviations for options have been explicity
6844 added to the option table so that they won't get overshadowed in the
6845 future by other options that begin with the same letter.
6849 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6850 Many assorted bugs have been handled. Many more remain to be handled.
6851 See the various ChangeLog files (primarily in gdb and bfd) for details.
6854 *** Changes in GDB-4.3:
6856 * New machines supported (host and target)
6858 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6859 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6860 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6862 * Almost SCO Unix support
6864 We had hoped to support:
6865 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6866 (except for core file support), but we discovered very late in the release
6867 that it has problems with process groups that render gdb unusable. Sorry
6868 about that. I encourage people to fix it and post the fixes.
6870 * Preliminary ELF and DWARF support
6872 GDB can read ELF object files on System V Release 4, and can handle
6873 debugging records for C, in DWARF format, in ELF files. This support
6874 is preliminary. If you bring up GDB on another SVR4 system, please
6875 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6880 GDB now uses the latest `readline' library. One user-visible change
6881 is that two tabs will list possible command completions, which previously
6882 required typing M-? (meta-question mark, or ESC ?).
6886 The `stepi' bug that many of you noticed has been squashed.
6887 Many bugs in C++ have been handled. Many more remain to be handled.
6888 See the various ChangeLog files (primarily in gdb and bfd) for details.
6890 * State of the MIPS world (in case you wondered):
6892 GDB can understand the symbol tables emitted by the compilers
6893 supplied by most vendors of MIPS-based machines, including DEC. These
6894 symbol tables are in a format that essentially nobody else uses.
6896 Some versions of gcc come with an assembler post-processor called
6897 mips-tfile. This program is required if you want to do source-level
6898 debugging of gcc-compiled programs. I believe FSF does not ship
6899 mips-tfile with gcc version 1, but it will eventually come with gcc
6902 Debugging of g++ output remains a problem. g++ version 1.xx does not
6903 really support it at all. (If you're lucky, you should be able to get
6904 line numbers and stack traces to work, but no parameters or local
6905 variables.) With some work it should be possible to improve the
6908 When gcc version 2 is released, you will have somewhat better luck.
6909 However, even then you will get confusing results for inheritance and
6912 We will eventually provide full debugging of g++ output on
6913 DECstations. This will probably involve some kind of stabs-in-ecoff
6914 encapulation, but the details have not been worked out yet.
6917 *** Changes in GDB-4.2:
6919 * Improved configuration
6921 Only one copy of `configure' exists now, and it is not self-modifying.
6922 Porting BFD is simpler.
6926 The `step' and `next' commands now only stop at the first instruction
6927 of a source line. This prevents the multiple stops that used to occur
6928 in switch statements, for-loops, etc. `Step' continues to stop if a
6929 function that has debugging information is called within the line.
6933 Lots of small bugs fixed. More remain.
6935 * New host supported (not target)
6937 Intel 386 PC clone running Mach i386-none-mach
6940 *** Changes in GDB-4.1:
6942 * Multiple source language support
6944 GDB now has internal scaffolding to handle several source languages.
6945 It determines the type of each source file from its filename extension,
6946 and will switch expression parsing and number formatting to match the
6947 language of the function in the currently selected stack frame.
6948 You can also specifically set the language to be used, with
6949 `set language c' or `set language modula-2'.
6953 GDB now has preliminary support for the GNU Modula-2 compiler,
6954 currently under development at the State University of New York at
6955 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6956 continue through the fall of 1991 and into 1992.
6958 Other Modula-2 compilers are currently not supported, and attempting to
6959 debug programs compiled with them will likely result in an error as the
6960 symbol table is read. Feel free to work on it, though!
6962 There are hooks in GDB for strict type checking and range checking,
6963 in the `Modula-2 philosophy', but they do not currently work.
6967 GDB can now write to executable and core files (e.g. patch
6968 a variable's value). You must turn this switch on, specify
6969 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6970 by assigning a new value to a variable. Modifications take
6973 * Automatic SunOS shared library reading
6975 When you run your program, GDB automatically determines where its
6976 shared libraries (if any) have been loaded, and reads their symbols.
6977 The `share' command is no longer needed. This also works when
6978 examining core files.
6982 You can specify the number of lines that the `list' command shows.
6985 * New machines supported (host and target)
6987 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6988 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6989 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6991 * New hosts supported (not targets)
6993 IBM RT/PC: romp-ibm-aix or rtpc
6995 * New targets supported (not hosts)
6997 AMD 29000 embedded with COFF a29k-none-coff
6998 AMD 29000 embedded with a.out a29k-none-aout
6999 Ultracomputer remote kernel debug a29k-nyu-kern
7001 * New remote interfaces
7007 *** Changes in GDB-4.0:
7011 Wide output is wrapped at good places to make the output more readable.
7013 Gdb now supports cross-debugging from a host machine of one type to a
7014 target machine of another type. Communication with the target system
7015 is over serial lines. The ``target'' command handles connecting to the
7016 remote system; the ``load'' command will download a program into the
7017 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7018 also supports debugging of realtime processes running under VxWorks,
7019 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7020 stub on the target system.
7022 New CPUs supported include the AMD 29000 and Intel 960.
7024 GDB now reads object files and symbol tables via a ``binary file''
7025 library, which allows a single copy of GDB to debug programs of multiple
7026 object file types such as a.out and coff.
7028 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7029 refcard.dvi and refcard.ps are available to format it).
7032 * Control-Variable user interface simplified
7034 All variables that control the operation of the debugger can be set
7035 by the ``set'' command, and displayed by the ``show'' command.
7037 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7038 ``Show prompt'' produces the response:
7039 Gdb's prompt is new-gdb=>.
7041 What follows are the NEW set commands. The command ``help set'' will
7042 print a complete list of old and new set commands. ``help set FOO''
7043 will give a longer description of the variable FOO. ``show'' will show
7044 all of the variable descriptions and their current settings.
7046 confirm on/off: Enables warning questions for operations that are
7047 hard to recover from, e.g. rerunning the program while
7048 it is already running. Default is ON.
7050 editing on/off: Enables EMACS style command line editing
7051 of input. Previous lines can be recalled with
7052 control-P, the current line can be edited with control-B,
7053 you can search for commands with control-R, etc.
7056 history filename NAME: NAME is where the gdb command history
7057 will be stored. The default is .gdb_history,
7058 or the value of the environment variable
7061 history size N: The size, in commands, of the command history. The
7062 default is 256, or the value of the environment variable
7065 history save on/off: If this value is set to ON, the history file will
7066 be saved after exiting gdb. If set to OFF, the
7067 file will not be saved. The default is OFF.
7069 history expansion on/off: If this value is set to ON, then csh-like
7070 history expansion will be performed on
7071 command line input. The default is OFF.
7073 radix N: Sets the default radix for input and output. It can be set
7074 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7075 in the current radix, so "set radix 10" is always a no-op.
7077 height N: This integer value is the number of lines on a page. Default
7078 is 24, the current `stty rows'' setting, or the ``li#''
7079 setting from the termcap entry matching the environment
7082 width N: This integer value is the number of characters on a line.
7083 Default is 80, the current `stty cols'' setting, or the ``co#''
7084 setting from the termcap entry matching the environment
7087 Note: ``set screensize'' is obsolete. Use ``set height'' and
7088 ``set width'' instead.
7090 print address on/off: Print memory addresses in various command displays,
7091 such as stack traces and structure values. Gdb looks
7092 more ``symbolic'' if you turn this off; it looks more
7093 ``machine level'' with it on. Default is ON.
7095 print array on/off: Prettyprint arrays. New convenient format! Default
7098 print demangle on/off: Print C++ symbols in "source" form if on,
7101 print asm-demangle on/off: Same, for assembler level printouts
7104 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7107 * Support for Epoch Environment.
7109 The epoch environment is a version of Emacs v18 with windowing. One
7110 new command, ``inspect'', is identical to ``print'', except that if you
7111 are running in the epoch environment, the value is printed in its own
7115 * Support for Shared Libraries
7117 GDB can now debug programs and core files that use SunOS shared libraries.
7118 Symbols from a shared library cannot be referenced
7119 before the shared library has been linked with the program (this
7120 happens after you type ``run'' and before the function main() is entered).
7121 At any time after this linking (including when examining core files
7122 from dynamically linked programs), gdb reads the symbols from each
7123 shared library when you type the ``sharedlibrary'' command.
7124 It can be abbreviated ``share''.
7126 sharedlibrary REGEXP: Load shared object library symbols for files
7127 matching a unix regular expression. No argument
7128 indicates to load symbols for all shared libraries.
7130 info sharedlibrary: Status of loaded shared libraries.
7135 A watchpoint stops execution of a program whenever the value of an
7136 expression changes. Checking for this slows down execution
7137 tremendously whenever you are in the scope of the expression, but is
7138 quite useful for catching tough ``bit-spreader'' or pointer misuse
7139 problems. Some machines such as the 386 have hardware for doing this
7140 more quickly, and future versions of gdb will use this hardware.
7142 watch EXP: Set a watchpoint (breakpoint) for an expression.
7144 info watchpoints: Information about your watchpoints.
7146 delete N: Deletes watchpoint number N (same as breakpoints).
7147 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7148 enable N: Re-enables watchpoint number N (same as breakpoints).
7151 * C++ multiple inheritance
7153 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7156 * C++ exception handling
7158 Gdb now supports limited C++ exception handling. Besides the existing
7159 ability to breakpoint on an exception handler, gdb can breakpoint on
7160 the raising of an exception (before the stack is peeled back to the
7163 catch FOO: If there is a FOO exception handler in the dynamic scope,
7164 set a breakpoint to catch exceptions which may be raised there.
7165 Multiple exceptions (``catch foo bar baz'') may be caught.
7167 info catch: Lists all exceptions which may be caught in the
7168 current stack frame.
7171 * Minor command changes
7173 The command ``call func (arg, arg, ...)'' now acts like the print
7174 command, except it does not print or save a value if the function's result
7175 is void. This is similar to dbx usage.
7177 The ``up'' and ``down'' commands now always print the frame they end up
7178 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7179 frames without printing.
7181 * New directory command
7183 'dir' now adds directories to the FRONT of the source search path.
7184 The path starts off empty. Source files that contain debug information
7185 about the directory in which they were compiled can be found even
7186 with an empty path; Sun CC and GCC include this information. If GDB can't
7187 find your source file in the current directory, type "dir .".
7189 * Configuring GDB for compilation
7191 For normal use, type ``./configure host''. See README or gdb.texinfo
7194 GDB now handles cross debugging. If you are remotely debugging between
7195 two different machines, type ``./configure host -target=targ''.
7196 Host is the machine where GDB will run; targ is the machine
7197 where the program that you are debugging will run.