1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support access to additional registers on
7 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
10 * GDB now has experimental support for the compilation and injection of
11 C++ source code into the inferior. This beta release does not include
12 support for several language features, such as templates, constructors,
15 This feature requires GCC 7.1 or higher built with libcp1.so
18 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
19 can be passed using the '[ADDRESS]:PORT' notation, or the regular
20 'ADDRESS:PORT' method.
22 * DWARF index cache: GDB can now automatically save indices of DWARF
23 symbols on disk to speed up further loading of the same binaries.
25 * Ada task switching is now supported on aarch64-elf targets when
26 debugging a program using the Ravenscar Profile. For more information,
27 see the "Tasking Support when using the Ravenscar Profile" section
28 in the GDB user manual.
30 * GDB in batch mode now exits with status 1 if the last command to be
33 * Changes to the "frame", "select-frame", and "info frame" CLI
34 commands. These commands all now take a frame specification which
35 is either a frame level, or one of the keywords 'level', 'address',
36 'function', or 'view' followed by a parameter. Selecting a frame by
37 address, or viewing a frame outside the current backtrace now
38 requires the use of a keyword. Selecting a frame by level is
39 unchanged. The MI comment "-stack-select-frame" is unchanged.
47 set debug compile-cplus-types
48 show debug compile-cplus-types
49 Control the display of debug output about type conversion in the
50 C++ compile feature. Commands have no effect while compiliong
55 Control whether debug output about files/functions skipping is
58 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
59 Apply a command to some frames.
60 FLAG arguments allow to control what output to produce and how to handle
61 errors raised when applying COMMAND to a frame.
64 Apply a command to all threads (ignoring errors and empty output).
65 Shortcut for 'thread apply all -s COMMAND'.
68 Apply a command to all frames (ignoring errors and empty output).
69 Shortcut for 'frame apply all -s COMMAND'.
72 Apply a command to all frames of all threads (ignoring errors and empty
74 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
76 maint set dwarf unwinders (on|off)
77 maint show dwarf unwinders
78 Control whether DWARF unwinders can be used.
81 Display a list of open files for a process.
85 target remote FILENAME
86 target extended-remote FILENAME
87 If FILENAME is a Unix domain socket, GDB will attempt to connect
88 to this socket instead of opening FILENAME as a character device.
90 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
91 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
92 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
93 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
94 These commands can now print only the searched entities
95 matching the provided regexp(s), giving a condition
96 on the entity names or entity types. The flag -q disables
97 printing headers or informations messages.
99 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
100 The 'thread apply' command accepts new FLAG arguments.
101 FLAG arguments allow to control what output to produce and how to handle
102 errors raised when applying COMMAND to a thread.
104 set tui tab-width NCHARS
105 show tui tab-width NCHARS
106 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
110 ** The '-data-disassemble' MI command now accepts an '-a' option to
111 disassemble the whole function surrounding the given program
112 counter value or function name. Support for this feature can be
113 verified by using the "-list-features" command, which should
114 contain "data-disassemble-a-option".
116 ** Command responses and notifications that include a frame now include
117 the frame's architecture in a new "arch" attribute.
119 * New native configurations
121 GNU/Linux/RISC-V riscv*-*-linux*
122 FreeBSD/riscv riscv*-*-freebsd*
126 GNU/Linux/RISC-V riscv*-*-linux*
128 CSKY GNU/LINUX csky*-*-linux
129 FreeBSD/riscv riscv*-*-freebsd*
133 ** The gdb.Inferior type has a new 'progspace' property, which is the program
134 space associated to that inferior.
136 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
137 of objfiles associated to that program space.
139 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
140 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
143 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
144 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
145 correct and did not work properly.
151 Enable or disable the undefined behavior sanitizer. This is
152 disabled by default, but passing --enable-ubsan=yes or
153 --enable-ubsan=auto to configure will enable it. Enabling this can
154 cause a performance penalty. The undefined behavior sanitizer was
155 first introduced in GCC 4.9.
157 *** Changes in GDB 8.2
159 * The 'set disassembler-options' command now supports specifying options
162 * The 'symbol-file' command now accepts an '-o' option to add a relative
163 offset to all sections.
165 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
166 a relative offset to all sections, but it allows to override the load
167 address of individual sections using '-s'.
169 * The 'add-symbol-file' command no longer requires the second argument
170 (address of the text section).
172 * The endianness used with the 'set endian auto' mode in the absence of
173 an executable selected for debugging is now the last endianness chosen
174 either by one of the 'set endian big' and 'set endian little' commands
175 or by inferring from the last executable used, rather than the startup
178 * The pager now allows a "c" response, meaning to disable the pager
179 for the rest of the current command.
181 * The commands 'info variables/functions/types' now show the source line
182 numbers of symbol definitions when available.
184 * 'info proc' now works on running processes on FreeBSD systems and core
185 files created on FreeBSD systems.
187 * C expressions can now use _Alignof, and C++ expressions can now use
190 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
191 the vector length while the process is running.
197 Control display of debugging info regarding the FreeBSD native target.
199 set|show varsize-limit
200 This new setting allows the user to control the maximum size of Ada
201 objects being printed when those objects have a variable type,
202 instead of that maximum size being hardcoded to 65536 bytes.
204 set|show record btrace cpu
205 Controls the processor to be used for enabling errata workarounds for
208 maint check libthread-db
209 Run integrity checks on the current inferior's thread debugging
212 maint set check-libthread-db (on|off)
213 maint show check-libthread-db
214 Control whether to run integrity checks on inferior specific thread
215 debugging libraries as they are loaded. The default is not to
220 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
222 ** The commands attached to a breakpoint can be set by assigning to
223 the breakpoint's "commands" field.
225 ** gdb.execute can now execute multi-line gdb commands.
227 ** The new functions gdb.convenience_variable and
228 gdb.set_convenience_variable can be used to get and set the value
229 of convenience variables.
231 ** A gdb.Parameter will no longer print the "set" help text on an
232 ordinary "set"; instead by default a "set" will be silent unless
233 the get_set_string method returns a non-empty string.
237 RiscV ELF riscv*-*-elf
239 * Removed targets and native configurations
241 m88k running OpenBSD m88*-*-openbsd*
242 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
243 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
244 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
246 * Aarch64/Linux hardware watchpoints improvements
248 Hardware watchpoints on unaligned addresses are now properly
249 supported when running Linux kernel 4.10 or higher: read and access
250 watchpoints are no longer spuriously missed, and all watchpoints
251 lengths between 1 and 8 bytes are supported. On older kernels,
252 watchpoints set on unaligned addresses are no longer missed, with
253 the tradeoff that there is a possibility of false hits being
258 --enable-codesign=CERT
259 This can be used to invoke "codesign -s CERT" after building gdb.
260 This option is useful on macOS, where code signing is required for
261 gdb to work properly.
263 --disable-gdbcli has been removed
264 This is now silently accepted, but does nothing.
266 *** Changes in GDB 8.1
268 * GDB now supports dynamically creating arbitrary register groups specified
269 in XML target descriptions. This allows for finer grain grouping of
270 registers on systems with a large amount of registers.
272 * The 'ptype' command now accepts a '/o' flag, which prints the
273 offsets and sizes of fields in a struct, like the pahole(1) tool.
275 * New "--readnever" command line option instructs GDB to not read each
276 symbol file's symbolic debug information. This makes startup faster
277 but at the expense of not being able to perform symbolic debugging.
278 This option is intended for use cases where symbolic debugging will
279 not be used, e.g., when you only need to dump the debuggee's core.
281 * GDB now uses the GNU MPFR library, if available, to emulate target
282 floating-point arithmetic during expression evaluation when the target
283 uses different floating-point formats than the host. At least version
284 3.1 of GNU MPFR is required.
286 * GDB now supports access to the guarded-storage-control registers and the
287 software-based guarded-storage broadcast control registers on IBM z14.
289 * On Unix systems, GDB now supports transmitting environment variables
290 that are to be set or unset to GDBserver. These variables will
291 affect the environment to be passed to the remote inferior.
293 To inform GDB of environment variables that are to be transmitted to
294 GDBserver, use the "set environment" command. Only user set
295 environment variables are sent to GDBserver.
297 To inform GDB of environment variables that are to be unset before
298 the remote inferior is started by the GDBserver, use the "unset
299 environment" command.
301 * Completion improvements
303 ** GDB can now complete function parameters in linespecs and
304 explicit locations without quoting. When setting breakpoints,
305 quoting around functions names to help with TAB-completion is
306 generally no longer necessary. For example, this now completes
309 (gdb) b function(in[TAB]
310 (gdb) b function(int)
312 Related, GDB is no longer confused with completing functions in
313 C++ anonymous namespaces:
316 (gdb) b (anonymous namespace)::[TAB][TAB]
317 (anonymous namespace)::a_function()
318 (anonymous namespace)::b_function()
320 ** GDB now has much improved linespec and explicit locations TAB
321 completion support, that better understands what you're
322 completing and offers better suggestions. For example, GDB no
323 longer offers data symbols as possible completions when you're
324 setting a breakpoint.
326 ** GDB now TAB-completes label symbol names.
328 ** The "complete" command now mimics TAB completion accurately.
330 * New command line options (gcore)
333 Dump all memory mappings.
335 * Breakpoints on C++ functions are now set on all scopes by default
337 By default, breakpoints on functions/methods are now interpreted as
338 specifying all functions with the given name ignoring missing
339 leading scopes (namespaces and classes).
341 For example, assuming a C++ program with symbols named:
346 both commands "break func()" and "break B::func()" set a breakpoint
349 You can use the new flag "-qualified" to override this. This makes
350 GDB interpret the specified function name as a complete
351 fully-qualified name instead. For example, using the same C++
352 program, the "break -q B::func" command sets a breakpoint on
353 "B::func", only. A parameter has been added to the Python
354 gdb.Breakpoint constructor to achieve the same result when creating
355 a breakpoint from Python.
357 * Breakpoints on functions marked with C++ ABI tags
359 GDB can now set breakpoints on functions marked with C++ ABI tags
360 (e.g., [abi:cxx11]). See here for a description of ABI tags:
361 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
363 Functions with a C++11 abi tag are demangled/displayed like this:
365 function[abi:cxx11](int)
368 You can now set a breakpoint on such functions simply as if they had
371 (gdb) b function(int)
373 Or if you need to disambiguate between tags, like:
375 (gdb) b function[abi:other_tag](int)
377 Tab completion was adjusted accordingly as well.
381 ** New events gdb.new_inferior, gdb.inferior_deleted, and
382 gdb.new_thread are emitted. See the manual for further
383 description of these.
385 ** A new function, "gdb.rbreak" has been added to the Python API.
386 This function allows the setting of a large number of breakpoints
387 via a regex pattern in Python. See the manual for further details.
389 ** Python breakpoints can now accept explicit locations. See the
390 manual for a further description of this feature.
393 * New features in the GDB remote stub, GDBserver
395 ** GDBserver is now able to start inferior processes with a
396 specified initial working directory.
398 The user can set the desired working directory to be used from
399 GDB using the new "set cwd" command.
401 ** New "--selftest" command line option runs some GDBserver self
402 tests. These self tests are disabled in releases.
404 ** On Unix systems, GDBserver now does globbing expansion and variable
405 substitution in inferior command line arguments.
407 This is done by starting inferiors using a shell, like GDB does.
408 See "set startup-with-shell" in the user manual for how to disable
409 this from GDB when using "target extended-remote". When using
410 "target remote", you can disable the startup with shell by using the
411 new "--no-startup-with-shell" GDBserver command line option.
413 ** On Unix systems, GDBserver now supports receiving environment
414 variables that are to be set or unset from GDB. These variables
415 will affect the environment to be passed to the inferior.
417 * When catching an Ada exception raised with a message, GDB now prints
418 the message in the catchpoint hit notification. In GDB/MI mode, that
419 information is provided as an extra field named "exception-message"
420 in the *stopped notification.
422 * Trait objects can now be inspected When debugging Rust code. This
423 requires compiler support which will appear in Rust 1.24.
427 QEnvironmentHexEncoded
428 Inform GDBserver of an environment variable that is to be passed to
429 the inferior when starting it.
432 Inform GDBserver of an environment variable that is to be unset
433 before starting the remote inferior.
436 Inform GDBserver that the environment should be reset (i.e.,
437 user-set environment variables should be unset).
440 Indicates whether the inferior must be started with a shell or not.
443 Tell GDBserver that the inferior to be started should use a specific
446 * The "maintenance print c-tdesc" command now takes an optional
447 argument which is the file name of XML target description.
449 * The "maintenance selftest" command now takes an optional argument to
450 filter the tests to be run.
452 * The "enable", and "disable" commands now accept a range of
453 breakpoint locations, e.g. "enable 1.3-5".
458 Set and show the current working directory for the inferior.
461 Set and show compilation command used for compiling and injecting code
462 with the 'compile' commands.
464 set debug separate-debug-file
465 show debug separate-debug-file
466 Control the display of debug output about separate debug file search.
468 set dump-excluded-mappings
469 show dump-excluded-mappings
470 Control whether mappings marked with the VM_DONTDUMP flag should be
471 dumped when generating a core file.
474 List the registered selftests.
477 Start the debugged program stopping at the first instruction.
480 Control display of debugging messages related to OpenRISC targets.
482 set|show print type nested-type-limit
483 Set and show the limit of nesting level for nested types that the
484 type printer will show.
486 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
489 * Safer/improved support for debugging with no debug info
491 GDB no longer assumes functions with no debug information return
494 This means that GDB now refuses to call such functions unless you
495 tell it the function's type, by either casting the call to the
496 declared return type, or by casting the function to a function
497 pointer of the right type, and calling that:
499 (gdb) p getenv ("PATH")
500 'getenv' has unknown return type; cast the call to its declared return type
501 (gdb) p (char *) getenv ("PATH")
502 $1 = 0x7fffffffe "/usr/local/bin:/"...
503 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
504 $2 = 0x7fffffffe "/usr/local/bin:/"...
506 Similarly, GDB no longer assumes that global variables with no debug
507 info have type 'int', and refuses to print the variable's value
508 unless you tell it the variable's type:
511 'var' has unknown type; cast it to its declared type
515 * New native configurations
517 FreeBSD/aarch64 aarch64*-*-freebsd*
518 FreeBSD/arm arm*-*-freebsd*
522 FreeBSD/aarch64 aarch64*-*-freebsd*
523 FreeBSD/arm arm*-*-freebsd*
524 OpenRISC ELF or1k*-*-elf
526 * Removed targets and native configurations
528 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
530 *** Changes in GDB 8.0
532 * GDB now supports access to the PKU register on GNU/Linux. The register is
533 added by the Memory Protection Keys for Userspace feature which will be
534 available in future Intel CPUs.
536 * GDB now supports C++11 rvalue references.
540 ** New functions to start, stop and access a running btrace recording.
541 ** Rvalue references are now supported in gdb.Type.
543 * GDB now supports recording and replaying rdrand and rdseed Intel 64
546 * Building GDB and GDBserver now requires a C++11 compiler.
548 For example, GCC 4.8 or later.
550 It is no longer possible to build GDB or GDBserver with a C
551 compiler. The --disable-build-with-cxx configure option has been
554 * Building GDB and GDBserver now requires GNU make >= 3.81.
556 It is no longer supported to build GDB or GDBserver with another
557 implementation of the make program or an earlier version of GNU make.
559 * Native debugging on MS-Windows supports command-line redirection
561 Command-line arguments used for starting programs on MS-Windows can
562 now include redirection symbols supported by native Windows shells,
563 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
564 as "run", "start", and "set args", as well as the corresponding MI
567 * Support for thread names on MS-Windows.
569 GDB now catches and handles the special exception that programs
570 running on MS-Windows use to assign names to threads in the
573 * Support for Java programs compiled with gcj has been removed.
575 * User commands now accept an unlimited number of arguments.
576 Previously, only up to 10 was accepted.
578 * The "eval" command now expands user-defined command arguments.
580 This makes it easier to process a variable number of arguments:
585 eval "print $arg%d", $i
590 * Target descriptions can now describe registers for sparc32 and sparc64.
592 * GDB now supports DWARF version 5 (debug information format).
593 Its .debug_names index is not yet supported.
595 * New native configurations
597 FreeBSD/mips mips*-*-freebsd
601 Synopsys ARC arc*-*-elf32
602 FreeBSD/mips mips*-*-freebsd
604 * Removed targets and native configurations
606 Alpha running FreeBSD alpha*-*-freebsd*
607 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
612 Erases all the flash memory regions reported by the target.
614 maint print arc arc-instruction address
615 Print internal disassembler information about instruction at a given address.
619 set disassembler-options
620 show disassembler-options
621 Controls the passing of target specific information to the disassembler.
622 If it is necessary to specify more than one disassembler option then
623 multiple options can be placed together into a comma separated list.
624 The default value is the empty string. Currently, the only supported
625 targets are ARM, PowerPC and S/390.
630 Erases all the flash memory regions reported by the target. This is
631 equivalent to the CLI command flash-erase.
633 -file-list-shared-libraries
634 List the shared libraries in the program. This is
635 equivalent to the CLI command "info shared".
638 Catchpoints stopping the program when Ada exceptions are
639 handled. This is equivalent to the CLI command "catch handlers".
641 *** Changes in GDB 7.12
643 * GDB and GDBserver now build with a C++ compiler by default.
645 The --enable-build-with-cxx configure option is now enabled by
646 default. One must now explicitly configure with
647 --disable-build-with-cxx in order to build with a C compiler. This
648 option will be removed in a future release.
650 * GDBserver now supports recording btrace without maintaining an active
653 * GDB now supports a negative repeat count in the 'x' command to examine
654 memory backward from the given address. For example:
657 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
658 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
659 (gdb) x/-5i 0x0000000000400580
660 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
661 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
662 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
663 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
664 0x40057b <main(int, char**)+25>:
665 callq 0x400536 <Func1(int, char const*)>
667 * Fortran: Support structures with fields of dynamic types and
668 arrays of dynamic types.
670 * The symbol dumping maintenance commands have new syntax.
671 maint print symbols [-pc address] [--] [filename]
672 maint print symbols [-objfile objfile] [-source source] [--] [filename]
673 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
674 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
675 maint print msymbols [-objfile objfile] [--] [filename]
677 * GDB now supports multibit bitfields and enums in target register
680 * New Python-based convenience function $_as_string(val), which returns
681 the textual representation of a value. This function is especially
682 useful to obtain the text label of an enum value.
684 * Intel MPX bound violation handling.
686 Segmentation faults caused by a Intel MPX boundary violation
687 now display the kind of violation (upper or lower), the memory
688 address accessed and the memory bounds, along with the usual
689 signal received and code location.
693 Program received signal SIGSEGV, Segmentation fault
694 Upper bound violation while accessing address 0x7fffffffc3b3
695 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
696 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
698 * Rust language support.
699 GDB now supports debugging programs written in the Rust programming
700 language. See https://www.rust-lang.org/ for more information about
703 * Support for running interpreters on specified input/output devices
705 GDB now supports a new mechanism that allows frontends to provide
706 fully featured GDB console views, as a better alternative to
707 building such views on top of the "-interpreter-exec console"
708 command. See the new "new-ui" command below. With that command,
709 frontends can now start GDB in the traditional command-line mode
710 running in an embedded terminal emulator widget, and create a
711 separate MI interpreter running on a specified i/o device. In this
712 way, GDB handles line editing, history, tab completion, etc. in the
713 console all by itself, and the GUI uses the separate MI interpreter
714 for its own control and synchronization, invisible to the command
717 * The "catch syscall" command catches groups of related syscalls.
719 The "catch syscall" command now supports catching a group of related
720 syscalls using the 'group:' or 'g:' prefix.
725 skip -gfile file-glob-pattern
726 skip -function function
727 skip -rfunction regular-expression
728 A generalized form of the skip command, with new support for
729 glob-style file names and regular expressions for function names.
730 Additionally, a file spec and a function spec may now be combined.
732 maint info line-table REGEXP
733 Display the contents of GDB's internal line table data struture.
736 Run any GDB unit tests that were compiled in.
739 Start a new user interface instance running INTERP as interpreter,
740 using the TTY file for input/output.
744 ** gdb.Breakpoint objects have a new attribute "pending", which
745 indicates whether the breakpoint is pending.
746 ** Three new breakpoint-related events have been added:
747 gdb.breakpoint_created, gdb.breakpoint_modified, and
748 gdb.breakpoint_deleted.
751 Signal ("set") the given MS-Windows event object. This is used in
752 conjunction with the Windows JIT debugging (AeDebug) support, where
753 the OS suspends a crashing process until a debugger can attach to
754 it. Resuming the crashing process, in order to debug it, is done by
757 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
758 was added in GDBserver, including JIT compiling fast tracepoint's
759 conditional expression bytecode into native code.
761 * Support for various remote target protocols and ROM monitors has
764 target m32rsdi Remote M32R debugging over SDI
765 target mips MIPS remote debugging protocol
766 target pmon PMON ROM monitor
767 target ddb NEC's DDB variant of PMON for Vr4300
768 target rockhopper NEC RockHopper variant of PMON
769 target lsi LSI variant of PMO
771 * Support for tracepoints and fast tracepoints on powerpc-linux,
772 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
773 including JIT compiling fast tracepoint's conditional expression
774 bytecode into native code.
776 * MI async record =record-started now includes the method and format used for
777 recording. For example:
779 =record-started,thread-group="i1",method="btrace",format="bts"
781 * MI async record =thread-selected now includes the frame field. For example:
783 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
787 Andes NDS32 nds32*-*-elf
789 *** Changes in GDB 7.11
791 * GDB now supports debugging kernel-based threads on FreeBSD.
793 * Per-inferior thread numbers
795 Thread numbers are now per inferior instead of global. If you're
796 debugging multiple inferiors, GDB displays thread IDs using a
797 qualified INF_NUM.THR_NUM form. For example:
801 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
802 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
803 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
804 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
806 As consequence, thread numbers as visible in the $_thread
807 convenience variable and in Python's InferiorThread.num attribute
808 are no longer unique between inferiors.
810 GDB now maintains a second thread ID per thread, referred to as the
811 global thread ID, which is the new equivalent of thread numbers in
812 previous releases. See also $_gthread below.
814 For backwards compatibility, MI's thread IDs always refer to global
817 * Commands that accept thread IDs now accept the qualified
818 INF_NUM.THR_NUM form as well. For example:
821 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
824 * In commands that accept a list of thread IDs, you can now refer to
825 all threads of an inferior using a star wildcard. GDB accepts
826 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
827 refer to all threads of the current inferior. For example, "info
830 * You can use "info threads -gid" to display the global thread ID of
833 * The new convenience variable $_gthread holds the global number of
836 * The new convenience variable $_inferior holds the number of the
839 * GDB now displays the ID and name of the thread that hit a breakpoint
840 or received a signal, if your program is multi-threaded. For
843 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
844 Thread 1 "main" received signal SIGINT, Interrupt.
846 * Record btrace now supports non-stop mode.
848 * Support for tracepoints on aarch64-linux was added in GDBserver.
850 * The 'record instruction-history' command now indicates speculative execution
851 when using the Intel Processor Trace recording format.
853 * GDB now allows users to specify explicit locations, bypassing
854 the linespec parser. This feature is also available to GDB/MI
857 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
858 GDB now is able to debug both AArch64 applications and ARM applications
861 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
862 including JIT compiling fast tracepoint's conditional expression bytecode
865 * GDB now supports displaced stepping on AArch64 GNU/Linux.
867 * "info threads", "info inferiors", "info display", "info checkpoints"
868 and "maint info program-spaces" now list the corresponding items in
869 ascending ID order, for consistency with all other "info" commands.
871 * In Ada, the overloads selection menu has been enhanced to display the
872 parameter types and the return types for the matching overloaded subprograms.
876 maint set target-non-stop (on|off|auto)
877 maint show target-non-stop
878 Control whether GDB targets always operate in non-stop mode even if
879 "set non-stop" is "off". The default is "auto", meaning non-stop
880 mode is enabled if supported by the target.
882 maint set bfd-sharing
883 maint show bfd-sharing
884 Control the reuse of bfd objects.
888 Control display of debugging info regarding bfd caching.
892 Control display of debugging info regarding FreeBSD threads.
894 set remote multiprocess-extensions-packet
895 show remote multiprocess-extensions-packet
896 Set/show the use of the remote protocol multiprocess extensions.
898 set remote thread-events
899 show remote thread-events
900 Set/show the use of thread create/exit events.
902 set ada print-signatures on|off
903 show ada print-signatures"
904 Control whether parameter types and return types are displayed in overloads
905 selection menus. It is activaled (@code{on}) by default.
909 Controls the maximum size of memory, in bytes, that GDB will
910 allocate for value contents. Prevents incorrect programs from
911 causing GDB to allocate overly large buffers. Default is 64k.
913 * The "disassemble" command accepts a new modifier: /s.
914 It prints mixed source+disassembly like /m with two differences:
915 - disassembled instructions are now printed in program order, and
916 - and source for all relevant files is now printed.
917 The "/m" option is now considered deprecated: its "source-centric"
918 output hasn't proved useful in practice.
920 * The "record instruction-history" command accepts a new modifier: /s.
921 It behaves exactly like /m and prints mixed source+disassembly.
923 * The "set scheduler-locking" command supports a new mode "replay".
924 It behaves like "off" in record mode and like "on" in replay mode.
926 * Support for various ROM monitors has been removed:
928 target dbug dBUG ROM monitor for Motorola ColdFire
929 target picobug Motorola picobug monitor
930 target dink32 DINK32 ROM monitor for PowerPC
931 target m32r Renesas M32R/D ROM monitor
932 target mon2000 mon2000 ROM monitor
933 target ppcbug PPCBUG ROM monitor for PowerPC
935 * Support for reading/writing memory and extracting values on architectures
936 whose memory is addressable in units of any integral multiple of 8 bits.
939 Allows to break when an Ada exception is handled.
944 Indicates that an exec system call was executed.
946 exec-events feature in qSupported
947 The qSupported packet allows GDB to request support for exec
948 events using the new 'gdbfeature' exec-event, and the qSupported
949 response can contain the corresponding 'stubfeature'. Set and
950 show commands can be used to display whether these features are enabled.
953 Equivalent to interrupting with the ^C character, but works in
956 thread created stop reason (T05 create:...)
957 Indicates that the thread was just created and is stopped at entry.
959 thread exit stop reply (w exitcode;tid)
960 Indicates that the thread has terminated.
963 Enables/disables thread create and exit event reporting. For
964 example, this is used in non-stop mode when GDB stops a set of
965 threads and synchronously waits for the their corresponding stop
966 replies. Without exit events, if one of the threads exits, GDB
967 would hang forever not knowing that it should no longer expect a
968 stop for that same thread.
971 Indicates that there are no resumed threads left in the target (all
972 threads are stopped). The remote stub reports support for this stop
973 reply to GDB's qSupported query.
976 Enables/disables catching syscalls from the inferior process.
977 The remote stub reports support for this packet to GDB's qSupported query.
979 syscall_entry stop reason
980 Indicates that a syscall was just called.
982 syscall_return stop reason
983 Indicates that a syscall just returned.
985 * Extended-remote exec events
987 ** GDB now has support for exec events on extended-remote Linux targets.
988 For such targets with Linux kernels 2.5.46 and later, this enables
989 follow-exec-mode and exec catchpoints.
991 set remote exec-event-feature-packet
992 show remote exec-event-feature-packet
993 Set/show the use of the remote exec event feature.
995 * Thread names in remote protocol
997 The reply to qXfer:threads:read may now include a name attribute for each
1000 * Target remote mode fork and exec events
1002 ** GDB now has support for fork and exec events on target remote mode
1003 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1004 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1005 fork and exec catchpoints.
1007 * Remote syscall events
1009 ** GDB now has support for catch syscall on remote Linux targets,
1010 currently enabled on x86/x86_64 architectures.
1012 set remote catch-syscall-packet
1013 show remote catch-syscall-packet
1014 Set/show the use of the remote catch syscall feature.
1018 ** The -var-set-format command now accepts the zero-hexadecimal
1019 format. It outputs data in hexadecimal format with zero-padding on the
1024 ** gdb.InferiorThread objects have a new attribute "global_num",
1025 which refers to the thread's global thread ID. The existing
1026 "num" attribute now refers to the thread's per-inferior number.
1027 See "Per-inferior thread numbers" above.
1028 ** gdb.InferiorThread objects have a new attribute "inferior", which
1029 is the Inferior object the thread belongs to.
1031 *** Changes in GDB 7.10
1033 * Support for process record-replay and reverse debugging on aarch64*-linux*
1034 targets has been added. GDB now supports recording of A64 instruction set
1035 including advance SIMD instructions.
1037 * Support for Sun's version of the "stabs" debug file format has been removed.
1039 * GDB now honors the content of the file /proc/PID/coredump_filter
1040 (PID is the process ID) on GNU/Linux systems. This file can be used
1041 to specify the types of memory mappings that will be included in a
1042 corefile. For more information, please refer to the manual page of
1043 "core(5)". GDB also has a new command: "set use-coredump-filter
1044 on|off". It allows to set whether GDB will read the content of the
1045 /proc/PID/coredump_filter file when generating a corefile.
1047 * The "info os" command on GNU/Linux can now display information on
1049 "info os cpus" Listing of all cpus/cores on the system
1051 * GDB has two new commands: "set serial parity odd|even|none" and
1052 "show serial parity". These allows to set or show parity for the
1055 * The "info source" command now displays the producer string if it was
1056 present in the debug info. This typically includes the compiler version
1057 and may include things like its command line arguments.
1059 * The "info dll", an alias of the "info sharedlibrary" command,
1060 is now available on all platforms.
1062 * Directory names supplied to the "set sysroot" commands may be
1063 prefixed with "target:" to tell GDB to access shared libraries from
1064 the target system, be it local or remote. This replaces the prefix
1065 "remote:". The default sysroot has been changed from "" to
1066 "target:". "remote:" is automatically converted to "target:" for
1067 backward compatibility.
1069 * The system root specified by "set sysroot" will be prepended to the
1070 filename of the main executable (if reported to GDB as absolute by
1071 the operating system) when starting processes remotely, and when
1072 attaching to already-running local or remote processes.
1074 * GDB now supports automatic location and retrieval of executable
1075 files from remote targets. Remote debugging can now be initiated
1076 using only a "target remote" or "target extended-remote" command
1077 (no "set sysroot" or "file" commands are required). See "New remote
1080 * The "dump" command now supports verilog hex format.
1082 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1084 * On GNU/Linux, GDB and gdbserver are now able to access executable
1085 and shared library files without a "set sysroot" command when
1086 attaching to processes running in different mount namespaces from
1087 the debugger. This makes it possible to attach to processes in
1088 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1089 See "New remote packets" below.
1091 * The "tui reg" command now provides completion for all of the
1092 available register groups, including target specific groups.
1094 * The HISTSIZE environment variable is no longer read when determining
1095 the size of GDB's command history. GDB now instead reads the dedicated
1096 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1097 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1102 ** Memory ports can now be unbuffered.
1106 ** gdb.Objfile objects have a new attribute "username",
1107 which is the name of the objfile as specified by the user,
1108 without, for example, resolving symlinks.
1109 ** You can now write frame unwinders in Python.
1110 ** gdb.Type objects have a new method "optimized_out",
1111 returning optimized out gdb.Value instance of this type.
1112 ** gdb.Value objects have new methods "reference_value" and
1113 "const_value" which return a reference to the value and a
1114 "const" version of the value respectively.
1118 maint print symbol-cache
1119 Print the contents of the symbol cache.
1121 maint print symbol-cache-statistics
1122 Print statistics of symbol cache usage.
1124 maint flush-symbol-cache
1125 Flush the contents of the symbol cache.
1129 Start branch trace recording using Branch Trace Store (BTS) format.
1132 Evaluate expression by using the compiler and print result.
1136 Explicit commands for enabling and disabling tui mode.
1139 set mpx bound on i386 and amd64
1140 Support for bound table investigation on Intel MPX enabled applications.
1144 Start branch trace recording using Intel Processor Trace format.
1147 Print information about branch tracing internals.
1149 maint btrace packet-history
1150 Print the raw branch tracing data.
1152 maint btrace clear-packet-history
1153 Discard the stored raw branch tracing data.
1156 Discard all branch tracing data. It will be fetched and processed
1157 anew by the next "record" command.
1162 Renamed from "set debug dwarf2-die".
1163 show debug dwarf-die
1164 Renamed from "show debug dwarf2-die".
1166 set debug dwarf-read
1167 Renamed from "set debug dwarf2-read".
1168 show debug dwarf-read
1169 Renamed from "show debug dwarf2-read".
1171 maint set dwarf always-disassemble
1172 Renamed from "maint set dwarf2 always-disassemble".
1173 maint show dwarf always-disassemble
1174 Renamed from "maint show dwarf2 always-disassemble".
1176 maint set dwarf max-cache-age
1177 Renamed from "maint set dwarf2 max-cache-age".
1178 maint show dwarf max-cache-age
1179 Renamed from "maint show dwarf2 max-cache-age".
1181 set debug dwarf-line
1182 show debug dwarf-line
1183 Control display of debugging info regarding DWARF line processing.
1186 show max-completions
1187 Set the maximum number of candidates to be considered during
1188 completion. The default value is 200. This limit allows GDB
1189 to avoid generating large completion lists, the computation of
1190 which can cause the debugger to become temporarily unresponsive.
1192 set history remove-duplicates
1193 show history remove-duplicates
1194 Control the removal of duplicate history entries.
1196 maint set symbol-cache-size
1197 maint show symbol-cache-size
1198 Control the size of the symbol cache.
1200 set|show record btrace bts buffer-size
1201 Set and show the size of the ring buffer used for branch tracing in
1203 The obtained size may differ from the requested size. Use "info
1204 record" to see the obtained buffer size.
1206 set debug linux-namespaces
1207 show debug linux-namespaces
1208 Control display of debugging info regarding Linux namespaces.
1210 set|show record btrace pt buffer-size
1211 Set and show the size of the ring buffer used for branch tracing in
1212 Intel Processor Trace format.
1213 The obtained size may differ from the requested size. Use "info
1214 record" to see the obtained buffer size.
1216 maint set|show btrace pt skip-pad
1217 Set and show whether PAD packets are skipped when computing the
1220 * The command 'thread apply all' can now support new option '-ascending'
1221 to call its specified command for all threads in ascending order.
1223 * Python/Guile scripting
1225 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1226 special section named `.debug_gdb_scripts'.
1228 * New remote packets
1230 qXfer:btrace-conf:read
1231 Return the branch trace configuration for the current thread.
1233 Qbtrace-conf:bts:size
1234 Set the requested ring buffer size for branch tracing in BTS format.
1237 Enable Intel Procesor Trace-based branch tracing for the current
1238 process. The remote stub reports support for this packet to GDB's
1241 Qbtrace-conf:pt:size
1242 Set the requested ring buffer size for branch tracing in Intel Processor
1246 Indicates a memory breakpoint instruction was executed, irrespective
1247 of whether it was GDB that planted the breakpoint or the breakpoint
1248 is hardcoded in the program. This is required for correct non-stop
1252 Indicates the target stopped for a hardware breakpoint. This is
1253 required for correct non-stop mode operation.
1256 Return information about files on the remote system.
1258 qXfer:exec-file:read
1259 Return the full absolute name of the file that was executed to
1260 create a process running on the remote system.
1263 Select the filesystem on which vFile: operations with filename
1264 arguments will operate. This is required for GDB to be able to
1265 access files on remote targets where the remote stub does not
1266 share a common filesystem with the inferior(s).
1269 Indicates that a fork system call was executed.
1272 Indicates that a vfork system call was executed.
1274 vforkdone stop reason
1275 Indicates that a vfork child of the specified process has executed
1276 an exec or exit, allowing the vfork parent to resume execution.
1278 fork-events and vfork-events features in qSupported
1279 The qSupported packet allows GDB to request support for fork and
1280 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1281 and the qSupported response can contain the corresponding
1282 'stubfeatures'. Set and show commands can be used to display
1283 whether these features are enabled.
1285 * Extended-remote fork events
1287 ** GDB now has support for fork events on extended-remote Linux
1288 targets. For targets with Linux kernels 2.5.60 and later, this
1289 enables follow-fork-mode and detach-on-fork for both fork and
1290 vfork, as well as fork and vfork catchpoints.
1292 * The info record command now shows the recording format and the
1293 branch tracing configuration for the current thread when using
1294 the btrace record target.
1295 For the BTS format, it shows the ring buffer size.
1297 * GDB now has support for DTrace USDT (Userland Static Defined
1298 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1300 * GDB now supports access to vector registers on S/390 GNU/Linux
1303 * Removed command line options
1305 -xdb HP-UX XDB compatibility mode.
1307 * Removed targets and native configurations
1309 HP/PA running HP-UX hppa*-*-hpux*
1310 Itanium running HP-UX ia64-*-hpux*
1312 * New configure options
1315 This configure option allows the user to build GDB with support for
1316 Intel Processor Trace (default: auto). This requires libipt.
1318 --with-libipt-prefix=PATH
1319 Specify the path to the version of libipt that GDB should use.
1320 $PATH/include should contain the intel-pt.h header and
1321 $PATH/lib should contain the libipt.so library.
1323 *** Changes in GDB 7.9.1
1327 ** Xmethods can now specify a result type.
1329 *** Changes in GDB 7.9
1331 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1335 ** You can now access frame registers from Python scripts.
1336 ** New attribute 'producer' for gdb.Symtab objects.
1337 ** gdb.Objfile objects have a new attribute "progspace",
1338 which is the gdb.Progspace object of the containing program space.
1339 ** gdb.Objfile objects have a new attribute "owner".
1340 ** gdb.Objfile objects have a new attribute "build_id",
1341 which is the build ID generated when the file was built.
1342 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1343 ** A new event "gdb.clear_objfiles" has been added, triggered when
1344 selecting a new file to debug.
1345 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1346 ** New function gdb.lookup_objfile.
1348 New events which are triggered when GDB modifies the state of the
1351 ** gdb.events.inferior_call_pre: Function call is about to be made.
1352 ** gdb.events.inferior_call_post: Function call has just been made.
1353 ** gdb.events.memory_changed: A memory location has been altered.
1354 ** gdb.events.register_changed: A register has been altered.
1356 * New Python-based convenience functions:
1358 ** $_caller_is(name [, number_of_frames])
1359 ** $_caller_matches(regexp [, number_of_frames])
1360 ** $_any_caller_is(name [, number_of_frames])
1361 ** $_any_caller_matches(regexp [, number_of_frames])
1363 * GDB now supports the compilation and injection of source code into
1364 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1365 to compile the source code to object code, and if successful, inject
1366 and execute that code within the current context of the inferior.
1367 Currently the C language is supported. The commands used to
1368 interface with this new feature are:
1370 compile code [-raw|-r] [--] [source code]
1371 compile file [-raw|-r] filename
1375 demangle [-l language] [--] name
1376 Demangle "name" in the specified language, or the current language
1377 if elided. This command is renamed from the "maint demangle" command.
1378 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1379 as "maint demangler-warning".
1381 queue-signal signal-name-or-number
1382 Queue a signal to be delivered to the thread when it is resumed.
1384 add-auto-load-scripts-directory directory
1385 Add entries to the list of directories from which to load auto-loaded
1388 maint print user-registers
1389 List all currently available "user" registers.
1391 compile code [-r|-raw] [--] [source code]
1392 Compile, inject, and execute in the inferior the executable object
1393 code produced by compiling the provided source code.
1395 compile file [-r|-raw] filename
1396 Compile and inject into the inferior the executable object code
1397 produced by compiling the source code stored in the filename
1400 * On resume, GDB now always passes the signal the program had stopped
1401 for to the thread the signal was sent to, even if the user changed
1402 threads before resuming. Previously GDB would often (but not
1403 always) deliver the signal to the thread that happens to be current
1406 * Conversely, the "signal" command now consistently delivers the
1407 requested signal to the current thread. GDB now asks for
1408 confirmation if the program had stopped for a signal and the user
1409 switched threads meanwhile.
1411 * "breakpoint always-inserted" modes "off" and "auto" merged.
1413 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1414 won't remove breakpoints from the target until all threads stop,
1415 even in non-stop mode. The "auto" mode has been removed, and "off"
1416 is now the default mode.
1420 set debug symbol-lookup
1421 show debug symbol-lookup
1422 Control display of debugging info regarding symbol lookup.
1426 ** The -list-thread-groups command outputs an exit-code field for
1427 inferiors that have exited.
1431 MIPS SDE mips*-sde*-elf*
1435 Support for these obsolete configurations has been removed.
1437 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1438 SGI Irix-5.x mips-*-irix5*
1439 SGI Irix-6.x mips-*-irix6*
1440 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1441 VAX running Ultrix vax-*-ultrix*
1443 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1444 and "assf"), have been removed. Use the "sharedlibrary" command, or
1445 its alias "share", instead.
1447 *** Changes in GDB 7.8
1449 * New command line options
1452 This is an alias for the --data-directory option.
1454 * GDB supports printing and modifying of variable length automatic arrays
1455 as specified in ISO C99.
1457 * The ARM simulator now supports instruction level tracing
1458 with or without disassembly.
1462 GDB now has support for scripting using Guile. Whether this is
1463 available is determined at configure time.
1464 Guile version 2.0 or greater is required.
1465 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1467 * New commands (for set/show, see "New options" below)
1471 Invoke CODE by passing it to the Guile interpreter.
1475 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1477 info auto-load guile-scripts [regexp]
1478 Print the list of automatically loaded Guile scripts.
1480 * The source command is now capable of sourcing Guile scripts.
1481 This feature is dependent on the debugger being built with Guile support.
1485 set print symbol-loading (off|brief|full)
1486 show print symbol-loading
1487 Control whether to print informational messages when loading symbol
1488 information for a file. The default is "full", but when debugging
1489 programs with large numbers of shared libraries the amount of output
1490 becomes less useful.
1492 set guile print-stack (none|message|full)
1493 show guile print-stack
1494 Show a stack trace when an error is encountered in a Guile script.
1496 set auto-load guile-scripts (on|off)
1497 show auto-load guile-scripts
1498 Control auto-loading of Guile script files.
1500 maint ada set ignore-descriptive-types (on|off)
1501 maint ada show ignore-descriptive-types
1502 Control whether the debugger should ignore descriptive types in Ada
1503 programs. The default is not to ignore the descriptive types. See
1504 the user manual for more details on descriptive types and the intended
1505 usage of this option.
1507 set auto-connect-native-target
1509 Control whether GDB is allowed to automatically connect to the
1510 native target for the run, attach, etc. commands when not connected
1511 to any target yet. See also "target native" below.
1513 set record btrace replay-memory-access (read-only|read-write)
1514 show record btrace replay-memory-access
1515 Control what memory accesses are allowed during replay.
1517 maint set target-async (on|off)
1518 maint show target-async
1519 This controls whether GDB targets operate in synchronous or
1520 asynchronous mode. Normally the default is asynchronous, if it is
1521 available; but this can be changed to more easily debug problems
1522 occurring only in synchronous mode.
1524 set mi-async (on|off)
1526 Control whether MI asynchronous mode is preferred. This supersedes
1527 "set target-async" of previous GDB versions.
1529 * "set target-async" is deprecated as a CLI option and is now an alias
1530 for "set mi-async" (only puts MI into async mode).
1532 * Background execution commands (e.g., "c&", "s&", etc.) are now
1533 possible ``out of the box'' if the target supports them. Previously
1534 the user would need to explicitly enable the possibility with the
1535 "set target-async on" command.
1537 * New features in the GDB remote stub, GDBserver
1539 ** New option --debug-format=option1[,option2,...] allows one to add
1540 additional text to each output. At present only timestamps
1541 are supported: --debug-format=timestamps.
1542 Timestamps can also be turned on with the
1543 "monitor set debug-format timestamps" command from GDB.
1545 * The 'record instruction-history' command now starts counting instructions
1546 at one. This also affects the instruction ranges reported by the
1547 'record function-call-history' command when given the /i modifier.
1549 * The command 'record function-call-history' supports a new modifier '/c' to
1550 indent the function names based on their call stack depth.
1551 The fields for the '/i' and '/l' modifier have been reordered.
1552 The source line range is now prefixed with 'at'.
1553 The instruction range is now prefixed with 'inst'.
1554 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1555 "record instruction-history" and "list" commands.
1557 * The ranges given as arguments to the 'record function-call-history' and
1558 'record instruction-history' commands are now inclusive.
1560 * The btrace record target now supports the 'record goto' command.
1561 For locations inside the execution trace, the back trace is computed
1562 based on the information stored in the execution trace.
1564 * The btrace record target supports limited reverse execution and replay.
1565 The target does not record data and therefore does not allow reading
1566 memory or registers.
1568 * The "catch syscall" command now works on s390*-linux* targets.
1570 * The "compare-sections" command is no longer specific to target
1571 remote. It now works with all targets.
1573 * All native targets are now consistently called "native".
1574 Consequently, the "target child", "target GNU", "target djgpp",
1575 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1576 commands have been replaced with "target native". The QNX/NTO port
1577 leaves the "procfs" target in place and adds a "native" target for
1578 consistency with other ports. The impact on users should be minimal
1579 as these commands previously either throwed an error, or were
1580 no-ops. The target's name is visible in the output of the following
1581 commands: "help target", "info target", "info files", "maint print
1584 * The "target native" command now connects to the native target. This
1585 can be used to launch native programs even when "set
1586 auto-connect-native-target" is set to off.
1588 * GDB now supports access to Intel MPX registers on GNU/Linux.
1590 * Support for Intel AVX-512 registers on GNU/Linux.
1591 Support displaying and modifying Intel AVX-512 registers
1592 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1594 * New remote packets
1596 qXfer:btrace:read's annex
1597 The qXfer:btrace:read packet supports a new annex 'delta' to read
1598 branch trace incrementally.
1602 ** Valid Python operations on gdb.Value objects representing
1603 structs/classes invoke the corresponding overloaded operators if
1605 ** New `Xmethods' feature in the Python API. Xmethods are
1606 additional methods or replacements for existing methods of a C++
1607 class. This feature is useful for those cases where a method
1608 defined in C++ source code could be inlined or optimized out by
1609 the compiler, making it unavailable to GDB.
1612 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1614 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1615 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1616 its alias "share", instead.
1618 * The commands "set remotebaud" and "show remotebaud" are no longer
1619 supported. Use "set serial baud" and "show serial baud" (respectively)
1624 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1625 target-async". The latter is left as a deprecated alias of the
1626 former for backward compatibility. If the target supports it,
1627 CLI background execution commands are now always possible by
1628 default, independently of whether the frontend stated a
1629 preference for asynchronous execution with "-gdb-set mi-async".
1630 Previously "-gdb-set target-async off" affected both MI execution
1631 commands and CLI execution commands.
1633 *** Changes in GDB 7.7
1635 * Improved support for process record-replay and reverse debugging on
1636 arm*-linux* targets. Support for thumb32 and syscall instruction
1637 recording has been added.
1639 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1641 * GDB now supports Fission DWP file format version 2.
1642 http://gcc.gnu.org/wiki/DebugFission
1644 * New convenience function "$_isvoid", to check whether an expression
1645 is void. A void expression is an expression where the type of the
1646 result is "void". For example, some convenience variables may be
1647 "void" when evaluated (e.g., "$_exitcode" before the execution of
1648 the program being debugged; or an undefined convenience variable).
1649 Another example, when calling a function whose return type is
1652 * The "maintenance print objfiles" command now takes an optional regexp.
1654 * The "catch syscall" command now works on arm*-linux* targets.
1656 * GDB now consistently shows "<not saved>" when printing values of
1657 registers the debug info indicates have not been saved in the frame
1658 and there's nowhere to retrieve them from
1659 (callee-saved/call-clobbered registers):
1664 (gdb) info registers rax
1667 Before, the former would print "<optimized out>", and the latter
1668 "*value not available*".
1670 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1675 ** Frame filters and frame decorators have been added.
1676 ** Temporary breakpoints are now supported.
1677 ** Line tables representation has been added.
1678 ** New attribute 'parent_type' for gdb.Field objects.
1679 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1680 ** New attribute 'name' for gdb.Type objects.
1684 Nios II ELF nios2*-*-elf
1685 Nios II GNU/Linux nios2*-*-linux
1686 Texas Instruments MSP430 msp430*-*-elf
1688 * Removed native configurations
1690 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1691 been removed. ELF variants of these configurations are kept supported.
1693 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1694 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1695 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1696 i[34567]86-*-openbsd3.[0-3]
1697 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1698 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1699 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1703 Like "catch throw", but catches a re-thrown exception.
1704 maint check-psymtabs
1705 Renamed from old "maint check-symtabs".
1707 Perform consistency checks on symtabs.
1708 maint expand-symtabs
1709 Expand symtabs matching an optional regexp.
1712 Display the details of GDB configure-time options.
1714 maint set|show per-command
1715 maint set|show per-command space
1716 maint set|show per-command time
1717 maint set|show per-command symtab
1718 Enable display of per-command gdb resource usage.
1720 remove-symbol-file FILENAME
1721 remove-symbol-file -a ADDRESS
1722 Remove a symbol file added via add-symbol-file. The file to remove
1723 can be identified by its filename or by an address that lies within
1724 the boundaries of this symbol file in memory.
1727 info exceptions REGEXP
1728 Display the list of Ada exceptions defined in the program being
1729 debugged. If provided, only the exceptions whose names match REGEXP
1734 set debug symfile off|on
1736 Control display of debugging info regarding reading symbol files and
1737 symbol tables within those files
1739 set print raw frame-arguments
1740 show print raw frame-arguments
1741 Set/show whether to print frame arguments in raw mode,
1742 disregarding any defined pretty-printers.
1744 set remote trace-status-packet
1745 show remote trace-status-packet
1746 Set/show the use of remote protocol qTStatus packet.
1750 Control display of debugging messages related to Nios II targets.
1754 Control whether target-assisted range stepping is enabled.
1756 set startup-with-shell
1757 show startup-with-shell
1758 Specifies whether Unix child processes are started via a shell or
1763 Use the target memory cache for accesses to the code segment. This
1764 improves performance of remote debugging (particularly disassembly).
1766 * You can now use a literal value 'unlimited' for options that
1767 interpret 0 or -1 as meaning "unlimited". E.g., "set
1768 trace-buffer-size unlimited" is now an alias for "set
1769 trace-buffer-size -1" and "set height unlimited" is now an alias for
1772 * The "set debug symtab-create" debugging option of GDB has been changed to
1773 accept a verbosity level. 0 means "off", 1 provides basic debugging
1774 output, and values of 2 or greater provides more verbose output.
1776 * New command-line options
1778 Display the details of GDB configure-time options.
1780 * The command 'tsave' can now support new option '-ctf' to save trace
1781 buffer in Common Trace Format.
1783 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1786 * GDB now implements the the C++ 'typeid' operator.
1788 * The new convenience variable $_exception holds the exception being
1789 thrown or caught at an exception-related catchpoint.
1791 * The exception-related catchpoints, like "catch throw", now accept a
1792 regular expression which can be used to filter exceptions by type.
1794 * The new convenience variable $_exitsignal is automatically set to
1795 the terminating signal number when the program being debugged dies
1796 due to an uncaught signal.
1800 ** All MI commands now accept an optional "--language" option.
1801 Support for this feature can be verified by using the "-list-features"
1802 command, which should contain "language-option".
1804 ** The new command -info-gdb-mi-command allows the user to determine
1805 whether a GDB/MI command is supported or not.
1807 ** The "^error" result record returned when trying to execute an undefined
1808 GDB/MI command now provides a variable named "code" whose content is the
1809 "undefined-command" error code. Support for this feature can be verified
1810 by using the "-list-features" command, which should contain
1811 "undefined-command-error-code".
1813 ** The -trace-save MI command can optionally save trace buffer in Common
1816 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1818 ** The command -data-list-register-values now accepts an optional
1819 "--skip-unavailable" option. When used, only the available registers
1822 ** The new command -trace-frame-collected dumps collected variables,
1823 computed expressions, tvars, memory and registers in a traceframe.
1825 ** The commands -stack-list-locals, -stack-list-arguments and
1826 -stack-list-variables now accept an option "--skip-unavailable".
1827 When used, only the available locals or arguments are displayed.
1829 ** The -exec-run command now accepts an optional "--start" option.
1830 When used, the command follows the same semantics as the "start"
1831 command, stopping the program's execution at the start of its
1832 main subprogram. Support for this feature can be verified using
1833 the "-list-features" command, which should contain
1834 "exec-run-start-option".
1836 ** The new commands -catch-assert and -catch-exceptions insert
1837 catchpoints stopping the program when Ada exceptions are raised.
1839 ** The new command -info-ada-exceptions provides the equivalent of
1840 the new "info exceptions" command.
1842 * New system-wide configuration scripts
1843 A GDB installation now provides scripts suitable for use as system-wide
1844 configuration scripts for the following systems:
1848 * GDB now supports target-assigned range stepping with remote targets.
1849 This improves the performance of stepping source lines by reducing
1850 the number of control packets from/to GDB. See "New remote packets"
1853 * GDB now understands the element 'tvar' in the XML traceframe info.
1854 It has the id of the collected trace state variables.
1856 * On S/390 targets that provide the transactional-execution feature,
1857 the program interruption transaction diagnostic block (TDB) is now
1858 represented as a number of additional "registers" in GDB.
1860 * New remote packets
1864 The vCont packet supports a new 'r' action, that tells the remote
1865 stub to step through an address range itself, without GDB
1866 involvemement at each single-step.
1868 qXfer:libraries-svr4:read's annex
1869 The previously unused annex of the qXfer:libraries-svr4:read packet
1870 is now used to support passing an argument list. The remote stub
1871 reports support for this argument list to GDB's qSupported query.
1872 The defined arguments are "start" and "prev", used to reduce work
1873 necessary for library list updating, resulting in significant
1876 * New features in the GDB remote stub, GDBserver
1878 ** GDBserver now supports target-assisted range stepping. Currently
1879 enabled on x86/x86_64 GNU/Linux targets.
1881 ** GDBserver now adds element 'tvar' in the XML in the reply to
1882 'qXfer:traceframe-info:read'. It has the id of the collected
1883 trace state variables.
1885 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1888 * New 'z' formatter for printing and examining memory, this displays the
1889 value as hexadecimal zero padded on the left to the size of the type.
1891 * GDB can now use Windows x64 unwinding data.
1893 * The "set remotebaud" command has been replaced by "set serial baud".
1894 Similarly, "show remotebaud" has been replaced by "show serial baud".
1895 The "set remotebaud" and "show remotebaud" commands are still available
1896 to provide backward compatibility with older versions of GDB.
1898 *** Changes in GDB 7.6
1900 * Target record has been renamed to record-full.
1901 Record/replay is now enabled with the "record full" command.
1902 This also affects settings that are associated with full record/replay
1903 that have been moved from "set/show record" to "set/show record full":
1905 set|show record full insn-number-max
1906 set|show record full stop-at-limit
1907 set|show record full memory-query
1909 * A new record target "record-btrace" has been added. The new target
1910 uses hardware support to record the control-flow of a process. It
1911 does not support replaying the execution, but it implements the
1912 below new commands for investigating the recorded execution log.
1913 This new recording method can be enabled using:
1917 The "record-btrace" target is only available on Intel Atom processors
1918 and requires a Linux kernel 2.6.32 or later.
1920 * Two new commands have been added for record/replay to give information
1921 about the recorded execution without having to replay the execution.
1922 The commands are only supported by "record btrace".
1924 record instruction-history prints the execution history at
1925 instruction granularity
1927 record function-call-history prints the execution history at
1928 function granularity
1930 * New native configurations
1932 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1933 FreeBSD/powerpc powerpc*-*-freebsd
1934 x86_64/Cygwin x86_64-*-cygwin*
1935 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1939 ARM AArch64 aarch64*-*-elf
1940 ARM AArch64 GNU/Linux aarch64*-*-linux
1941 Lynx 178 PowerPC powerpc-*-lynx*178
1942 x86_64/Cygwin x86_64-*-cygwin*
1943 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1945 * If the configured location of system.gdbinit file (as given by the
1946 --with-system-gdbinit option at configure time) is in the
1947 data-directory (as specified by --with-gdb-datadir at configure
1948 time) or in one of its subdirectories, then GDB will look for the
1949 system-wide init file in the directory specified by the
1950 --data-directory command-line option.
1952 * New command line options:
1954 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1955 other initialization files, unlike -nx which disables all of them.
1957 * Removed command line options
1959 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1962 * The 'ptype' and 'whatis' commands now accept an argument to control
1965 * 'info proc' now works on some core files.
1969 ** Vectors can be created with gdb.Type.vector.
1971 ** Python's atexit.register now works in GDB.
1973 ** Types can be pretty-printed via a Python API.
1975 ** Python 3 is now supported (in addition to Python 2.4 or later)
1977 ** New class gdb.Architecture exposes GDB's internal representation
1978 of architecture in the Python API.
1980 ** New method Frame.architecture returns the gdb.Architecture object
1981 corresponding to the frame's architecture.
1983 * New Python-based convenience functions:
1985 ** $_memeq(buf1, buf2, length)
1986 ** $_streq(str1, str2)
1988 ** $_regex(str, regex)
1990 * The 'cd' command now defaults to using '~' (the home directory) if not
1993 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1994 default for GCC since November 2000.
1996 * The command 'forward-search' can now be abbreviated as 'fo'.
1998 * The command 'info tracepoints' can now display 'installed on target'
1999 or 'not installed on target' for each non-pending location of tracepoint.
2001 * New configure options
2003 --enable-libmcheck/--disable-libmcheck
2004 By default, development versions are built with -lmcheck on hosts
2005 that support it, in order to help track memory corruption issues.
2006 Release versions, on the other hand, are built without -lmcheck
2007 by default. The --enable-libmcheck/--disable-libmcheck configure
2008 options allow the user to override that default.
2009 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2010 This configure option allows the user to build GDB with
2011 libbabeltrace using which GDB can read Common Trace Format data.
2013 * New commands (for set/show, see "New options" below)
2016 Catch signals. This is similar to "handle", but allows commands and
2017 conditions to be attached.
2020 List the BFDs known to GDB.
2022 python-interactive [command]
2024 Start a Python interactive prompt, or evaluate the optional command
2025 and print the result of expressions.
2028 "py" is a new alias for "python".
2030 enable type-printer [name]...
2031 disable type-printer [name]...
2032 Enable or disable type printers.
2036 ** For the Renesas Super-H architecture, the "regs" command has been removed
2037 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2042 set print type methods (on|off)
2043 show print type methods
2044 Control whether method declarations are displayed by "ptype".
2045 The default is to show them.
2047 set print type typedefs (on|off)
2048 show print type typedefs
2049 Control whether typedef definitions are displayed by "ptype".
2050 The default is to show them.
2052 set filename-display basename|relative|absolute
2053 show filename-display
2054 Control the way in which filenames is displayed.
2055 The default is "relative", which preserves previous behavior.
2057 set trace-buffer-size
2058 show trace-buffer-size
2059 Request target to change the size of trace buffer.
2061 set remote trace-buffer-size-packet auto|on|off
2062 show remote trace-buffer-size-packet
2063 Control the use of the remote protocol `QTBuffer:size' packet.
2067 Control display of debugging messages related to ARM AArch64.
2070 set debug coff-pe-read
2071 show debug coff-pe-read
2072 Control display of debugging messages related to reading of COFF/PE
2077 Control display of debugging messages related to Mach-O symbols
2080 set debug notification
2081 show debug notification
2082 Control display of debugging info for async remote notification.
2086 ** Command parameter changes are now notified using new async record
2087 "=cmd-param-changed".
2088 ** Trace frame changes caused by command "tfind" are now notified using
2089 new async record "=traceframe-changed".
2090 ** The creation, deletion and modification of trace state variables
2091 are now notified using new async records "=tsv-created",
2092 "=tsv-deleted" and "=tsv-modified".
2093 ** The start and stop of process record are now notified using new
2094 async record "=record-started" and "=record-stopped".
2095 ** Memory changes are now notified using new async record
2097 ** The data-disassemble command response will include a "fullname" field
2098 containing the absolute file name when source has been requested.
2099 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2100 command, to allow pattern filling of memory areas.
2101 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2102 library load/unload events.
2103 ** The response to breakpoint commands and breakpoint async records
2104 includes an "installed" field containing a boolean state about each
2105 non-pending tracepoint location is whether installed on target or not.
2106 ** Output of the "-trace-status" command includes a "trace-file" field
2107 containing the name of the trace file being examined. This field is
2108 optional, and only present when examining a trace file.
2109 ** The "fullname" field is now always present along with the "file" field,
2110 even if the file cannot be found by GDB.
2112 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2113 You must have the LZMA library available when configuring GDB for this
2114 feature to be enabled. For more information, see:
2115 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2117 * New remote packets
2120 Set the size of trace buffer. The remote stub reports support for this
2121 packet to gdb's qSupported query.
2124 Enable Branch Trace Store (BTS)-based branch tracing for the current
2125 thread. The remote stub reports support for this packet to gdb's
2129 Disable branch tracing for the current thread. The remote stub reports
2130 support for this packet to gdb's qSupported query.
2133 Read the traced branches for the current thread. The remote stub
2134 reports support for this packet to gdb's qSupported query.
2136 *** Changes in GDB 7.5
2138 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2139 for more x32 ABI info.
2141 * GDB now supports access to MIPS DSP registers on Linux targets.
2143 * GDB now supports debugging microMIPS binaries.
2145 * The "info os" command on GNU/Linux can now display information on
2146 several new classes of objects managed by the operating system:
2147 "info os procgroups" lists process groups
2148 "info os files" lists file descriptors
2149 "info os sockets" lists internet-domain sockets
2150 "info os shm" lists shared-memory regions
2151 "info os semaphores" lists semaphores
2152 "info os msg" lists message queues
2153 "info os modules" lists loaded kernel modules
2155 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2156 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2157 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2158 options and inspect the probe arguments using the new $_probe_arg family
2159 of convenience variables. You can obtain more information about SystemTap
2160 in <http://sourceware.org/systemtap/>.
2162 * GDB now supports reversible debugging on ARM, it allows you to
2163 debug basic ARM and THUMB instructions, and provides
2164 record/replay support.
2166 * The option "symbol-reloading" has been deleted as it is no longer used.
2170 ** GDB commands implemented in Python can now be put in command class
2173 ** The "maint set python print-stack on|off" is now deleted.
2175 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2176 apply "flag enum"-style pretty-printing to any enum.
2178 ** gdb.lookup_symbol can now work when there is no current frame.
2180 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2181 the source at which the symbol was defined.
2183 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2184 method 'value'. The former indicates whether the symbol needs a
2185 frame in order to compute its value, and the latter computes the
2188 ** A new method 'referenced_value' on gdb.Value objects which can
2189 dereference pointer as well as C++ reference values.
2191 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2192 which return the global and static blocks (as gdb.Block objects),
2193 of the underlying symbol table, respectively.
2195 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2196 object associated with a PC value.
2198 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2199 of the address range occupied by code for the current source line.
2201 * Go language support.
2202 GDB now supports debugging programs written in the Go programming
2205 * GDBserver now supports stdio connections.
2206 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2208 * The binary "gdbtui" can no longer be built or installed.
2209 Use "gdb -tui" instead.
2211 * GDB will now print "flag" enums specially. A flag enum is one where
2212 all the enumerator values have no bits in common when pairwise
2213 "and"ed. When printing a value whose type is a flag enum, GDB will
2214 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2215 (gdb) print (enum E) 3
2218 * The filename part of a linespec will now match trailing components
2219 of a source file name. For example, "break gcc/expr.c:1000" will
2220 now set a breakpoint in build/gcc/expr.c, but not
2221 build/libcpp/expr.c.
2223 * The "info proc" and "generate-core-file" commands will now also
2224 work on remote targets connected to GDBserver on Linux.
2226 * The command "info catch" has been removed. It has been disabled
2227 since December 2007.
2229 * The "catch exception" and "catch assert" commands now accept
2230 a condition at the end of the command, much like the "break"
2231 command does. For instance:
2233 (gdb) catch exception Constraint_Error if Barrier = True
2235 Previously, it was possible to add a condition to such catchpoints,
2236 but it had to be done as a second step, after the catchpoint had been
2237 created, using the "condition" command.
2239 * The "info static-tracepoint-marker" command will now also work on
2240 native Linux targets with in-process agent.
2242 * GDB can now set breakpoints on inlined functions.
2244 * The .gdb_index section has been updated to include symbols for
2245 inlined functions. GDB will ignore older .gdb_index sections by
2246 default, which could cause symbol files to be loaded more slowly
2247 until their .gdb_index sections can be recreated. The new command
2248 "set use-deprecated-index-sections on" will cause GDB to use any older
2249 .gdb_index sections it finds. This will restore performance, but the
2250 ability to set breakpoints on inlined functions will be lost in symbol
2251 files with older .gdb_index sections.
2253 The .gdb_index section has also been updated to record more information
2254 about each symbol. This speeds up the "info variables", "info functions"
2255 and "info types" commands when used with programs having the .gdb_index
2256 section, as well as speeding up debugging with shared libraries using
2257 the .gdb_index section.
2259 * Ada support for GDB/MI Variable Objects has been added.
2261 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2266 ** New command -info-os is the MI equivalent of "info os".
2268 ** Output logs ("set logging" and related) now include MI output.
2272 ** "set use-deprecated-index-sections on|off"
2273 "show use-deprecated-index-sections on|off"
2274 Controls the use of deprecated .gdb_index sections.
2276 ** "catch load" and "catch unload" can be used to stop when a shared
2277 library is loaded or unloaded, respectively.
2279 ** "enable count" can be used to auto-disable a breakpoint after
2282 ** "info vtbl" can be used to show the virtual method tables for
2283 C++ and Java objects.
2285 ** "explore" and its sub commands "explore value" and "explore type"
2286 can be used to recursively explore values and types of
2287 expressions. These commands are available only if GDB is
2288 configured with '--with-python'.
2290 ** "info auto-load" shows status of all kinds of auto-loaded files,
2291 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2292 sequences of commands files, "info auto-load python-scripts"
2293 shows status of auto-loading Python script files,
2294 "info auto-load local-gdbinit" shows status of loading init file
2295 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2296 status of inferior specific thread debugging shared library loading.
2298 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2299 and "show auto-load-scripts" commands have been deprecated, use their
2300 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2301 and "show auto-load python-scripts" counterparts instead.
2303 ** "dprintf location,format,args..." creates a dynamic printf, which
2304 is basically a breakpoint that does a printf and immediately
2305 resumes your program's execution, so it is like a printf that you
2306 can insert dynamically at runtime instead of at compiletime.
2308 ** "set print symbol"
2310 Controls whether GDB attempts to display the symbol, if any,
2311 corresponding to addresses it prints. This defaults to "on", but
2312 you can set it to "off" to restore GDB's previous behavior.
2314 * Deprecated commands
2316 ** For the Renesas Super-H architecture, the "regs" command has been
2317 deprecated, and "info all-registers" should be used instead.
2321 Renesas RL78 rl78-*-elf
2322 HP OpenVMS ia64 ia64-hp-openvms*
2324 * GDBserver supports evaluation of breakpoint conditions. When
2325 support is advertised by GDBserver, GDB may be told to send the
2326 breakpoint conditions in bytecode form to GDBserver. GDBserver
2327 will only report the breakpoint trigger to GDB when its condition
2332 set mips compression
2333 show mips compression
2334 Select the compressed ISA encoding used in functions that have no symbol
2335 information available. The encoding can be set to either of:
2338 and is updated automatically from ELF file flags if available.
2340 set breakpoint condition-evaluation
2341 show breakpoint condition-evaluation
2342 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2343 GDBserver ("target"). Default option "auto" chooses the most efficient
2345 This option can improve debugger efficiency depending on the speed of the
2349 Disable auto-loading globally.
2352 Show auto-loading setting of all kinds of auto-loaded files.
2354 set auto-load gdb-scripts on|off
2355 show auto-load gdb-scripts
2356 Control auto-loading of GDB canned sequences of commands files.
2358 set auto-load python-scripts on|off
2359 show auto-load python-scripts
2360 Control auto-loading of Python script files.
2362 set auto-load local-gdbinit on|off
2363 show auto-load local-gdbinit
2364 Control loading of init file (.gdbinit) from current directory.
2366 set auto-load libthread-db on|off
2367 show auto-load libthread-db
2368 Control auto-loading of inferior specific thread debugging shared library.
2370 set auto-load scripts-directory <dir1>[:<dir2>...]
2371 show auto-load scripts-directory
2372 Set a list of directories from which to load auto-loaded scripts.
2373 Automatically loaded Python scripts and GDB scripts are located in one
2374 of the directories listed by this option.
2375 The delimiter (':' above) may differ according to the host platform.
2377 set auto-load safe-path <dir1>[:<dir2>...]
2378 show auto-load safe-path
2379 Set a list of directories from which it is safe to auto-load files.
2380 The delimiter (':' above) may differ according to the host platform.
2382 set debug auto-load on|off
2383 show debug auto-load
2384 Control display of debugging info for auto-loading the files above.
2386 set dprintf-style gdb|call|agent
2388 Control the way in which a dynamic printf is performed; "gdb"
2389 requests a GDB printf command, while "call" causes dprintf to call a
2390 function in the inferior. "agent" requests that the target agent
2391 (such as GDBserver) do the printing.
2393 set dprintf-function <expr>
2394 show dprintf-function
2395 set dprintf-channel <expr>
2396 show dprintf-channel
2397 Set the function and optional first argument to the call when using
2398 the "call" style of dynamic printf.
2400 set disconnected-dprintf on|off
2401 show disconnected-dprintf
2402 Control whether agent-style dynamic printfs continue to be in effect
2403 after GDB disconnects.
2405 * New configure options
2407 --with-auto-load-dir
2408 Configure default value for the 'set auto-load scripts-directory'
2409 setting above. It defaults to '$debugdir:$datadir/auto-load',
2410 $debugdir representing global debugging info directories (available
2411 via 'show debug-file-directory') and $datadir representing GDB's data
2412 directory (available via 'show data-directory').
2414 --with-auto-load-safe-path
2415 Configure default value for the 'set auto-load safe-path' setting
2416 above. It defaults to the --with-auto-load-dir setting.
2418 --without-auto-load-safe-path
2419 Set 'set auto-load safe-path' to '/', effectively disabling this
2422 * New remote packets
2424 z0/z1 conditional breakpoints extension
2426 The z0/z1 breakpoint insertion packets have been extended to carry
2427 a list of conditional expressions over to the remote stub depending on the
2428 condition evaluation mode. The use of this extension can be controlled
2429 via the "set remote conditional-breakpoints-packet" command.
2433 Specify the signals which the remote stub may pass to the debugged
2434 program without GDB involvement.
2436 * New command line options
2438 --init-command=FILE, -ix Like --command, -x but execute it
2439 before loading inferior.
2440 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2441 execute it before loading inferior.
2443 *** Changes in GDB 7.4
2445 * GDB now handles ambiguous linespecs more consistently; the existing
2446 FILE:LINE support has been expanded to other types of linespecs. A
2447 breakpoint will now be set on all matching locations in all
2448 inferiors, and locations will be added or removed according to
2451 * GDB now allows you to skip uninteresting functions and files when
2452 stepping with the "skip function" and "skip file" commands.
2454 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2455 and "show remote hardware-watchpoint-length-limit". These allows to
2456 set or show the maximum length limit (in bytes) of a remote
2457 target hardware watchpoint.
2459 This allows e.g. to use "unlimited" hardware watchpoints with the
2460 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2461 watchpoints are slower than real hardware watchpoints but are
2462 significantly faster than gdb software watchpoints.
2466 ** The register_pretty_printer function in module gdb.printing now takes
2467 an optional `replace' argument. If True, the new printer replaces any
2470 ** The "maint set python print-stack on|off" command has been
2471 deprecated and will be deleted in GDB 7.5.
2472 A new command: "set python print-stack none|full|message" has
2473 replaced it. Additionally, the default for "print-stack" is
2474 now "message", which just prints the error message without
2477 ** A prompt substitution hook (prompt_hook) is now available to the
2480 ** A new Python module, gdb.prompt has been added to the GDB Python
2481 modules library. This module provides functionality for
2482 escape sequences in prompts (used by set/show
2483 extended-prompt). These escape sequences are replaced by their
2484 corresponding value.
2486 ** Python commands and convenience-functions located in
2487 'data-directory'/python/gdb/command and
2488 'data-directory'/python/gdb/function are now automatically loaded
2491 ** Blocks now provide four new attributes. global_block and
2492 static_block will return the global and static blocks
2493 respectively. is_static and is_global are boolean attributes
2494 that indicate if the block is one of those two types.
2496 ** Symbols now provide the "type" attribute, the type of the symbol.
2498 ** The "gdb.breakpoint" function has been deprecated in favor of
2501 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2502 of a function. This class is based on the "finish" command
2503 available in the CLI.
2505 ** Type objects for struct and union types now allow access to
2506 the fields using standard Python dictionary (mapping) methods.
2507 For example, "some_type['myfield']" now works, as does
2508 "some_type.items()".
2510 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2513 ** A new function, "deep_items" has been added to the gdb.types
2514 module in the GDB Python modules library. This function returns
2515 an iterator over the fields of a struct or union type. Unlike
2516 the standard Python "iteritems" method, it will recursively traverse
2517 any anonymous fields.
2521 ** "*stopped" events can report several new "reason"s, such as
2524 ** Breakpoint changes are now notified using new async records, like
2525 "=breakpoint-modified".
2527 ** New command -ada-task-info.
2529 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2530 $sdir specifies the default system locations of shared libraries.
2531 $pdir specifies the directory where the libpthread used by the application
2534 GDB no longer looks in $sdir and $pdir after it has searched the directories
2535 mentioned in libthread-db-search-path. If you want to search those
2536 directories, they must be specified in libthread-db-search-path.
2537 The default value of libthread-db-search-path on GNU/Linux and Solaris
2538 systems is now "$sdir:$pdir".
2540 $pdir is not supported by gdbserver, it is currently ignored.
2541 $sdir is supported by gdbserver.
2543 * New configure option --with-iconv-bin.
2544 When using the internationalization support like the one in the GNU C
2545 library, GDB will invoke the "iconv" program to get a list of supported
2546 character sets. If this program lives in a non-standard location, one can
2547 use this option to specify where to find it.
2549 * When natively debugging programs on PowerPC BookE processors running
2550 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2551 watchpoints, which specify a mask in addition to an address to watch.
2552 The mask specifies that some bits of an address (the bits which are
2553 reset in the mask) should be ignored when matching the address accessed
2554 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2555 section in the user manual for more details.
2557 * The new option --once causes GDBserver to stop listening for connections once
2558 the first connection is made. The listening port used by GDBserver will
2559 become available after that.
2561 * New commands "info macros" and "alias" have been added.
2563 * New function parameters suffix @entry specifies value of function parameter
2564 at the time the function got called. Entry values are available only since
2570 "!" is now an alias of the "shell" command.
2571 Note that no space is needed between "!" and SHELL COMMAND.
2575 watch EXPRESSION mask MASK_VALUE
2576 The watch command now supports the mask argument which allows creation
2577 of masked watchpoints, if the current architecture supports this feature.
2579 info auto-load-scripts [REGEXP]
2580 This command was formerly named "maintenance print section-scripts".
2581 It is now generally useful and is no longer a maintenance-only command.
2583 info macro [-all] [--] MACRO
2584 The info macro command has new options `-all' and `--'. The first for
2585 printing all definitions of a macro. The second for explicitly specifying
2586 the end of arguments and the beginning of the macro name in case the macro
2587 name starts with a hyphen.
2589 collect[/s] EXPRESSIONS
2590 The tracepoint collect command now takes an optional modifier "/s"
2591 that directs it to dereference pointer-to-character types and
2592 collect the bytes of memory up to a zero byte. The behavior is
2593 similar to what you see when you use the regular print command on a
2594 string. An optional integer following the "/s" sets a bound on the
2595 number of bytes that will be collected.
2598 The trace start command now interprets any supplied arguments as a
2599 note to be recorded with the trace run, with an effect similar to
2600 setting the variable trace-notes.
2603 The trace stop command now interprets any arguments as a note to be
2604 mentioned along with the tstatus report that the trace was stopped
2605 with a command. The effect is similar to setting the variable
2608 * Tracepoints can now be enabled and disabled at any time after a trace
2609 experiment has been started using the standard "enable" and "disable"
2610 commands. It is now possible to start a trace experiment with no enabled
2611 tracepoints; GDB will display a warning, but will allow the experiment to
2612 begin, assuming that tracepoints will be enabled as needed while the trace
2615 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2616 locations with 4-byte instructions, when they were previously
2617 limited to locations with instructions of 5 bytes or longer.
2621 set debug dwarf2-read
2622 show debug dwarf2-read
2623 Turns on or off display of debugging messages related to reading
2624 DWARF debug info. The default is off.
2626 set debug symtab-create
2627 show debug symtab-create
2628 Turns on or off display of debugging messages related to symbol table
2629 creation. The default is off.
2632 show extended-prompt
2633 Set the GDB prompt, and allow escape sequences to be inserted to
2634 display miscellaneous information (see 'help set extended-prompt'
2635 for the list of sequences). This prompt (and any information
2636 accessed through the escape sequences) is updated every time the
2637 prompt is displayed.
2639 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2640 show print entry-values
2641 Set printing of frame argument values at function entry. In some cases
2642 GDB can determine the value of function argument which was passed by the
2643 function caller, even if the value was modified inside the called function.
2645 set debug entry-values
2646 show debug entry-values
2647 Control display of debugging info for determining frame argument values at
2648 function entry and virtual tail call frames.
2650 set basenames-may-differ
2651 show basenames-may-differ
2652 Set whether a source file may have multiple base names.
2653 (A "base name" is the name of a file with the directory part removed.
2654 Example: The base name of "/home/user/hello.c" is "hello.c".)
2655 If set, GDB will canonicalize file names (e.g., expand symlinks)
2656 before comparing them. Canonicalization is an expensive operation,
2657 but it allows the same file be known by more than one base name.
2658 If not set (the default), all source files are assumed to have just
2659 one base name, and gdb will do file name comparisons more efficiently.
2665 Set a user name and notes for the current and any future trace runs.
2666 This is useful for long-running and/or disconnected traces, to
2667 inform others (or yourself) as to who is running the trace, supply
2668 contact information, or otherwise explain what is going on.
2670 set trace-stop-notes
2671 show trace-stop-notes
2672 Set a note attached to the trace run, that is displayed when the
2673 trace has been stopped by a tstop command. This is useful for
2674 instance as an explanation, if you are stopping a trace run that was
2675 started by someone else.
2677 * New remote packets
2681 Dynamically enable a tracepoint in a started trace experiment.
2685 Dynamically disable a tracepoint in a started trace experiment.
2689 Set the user and notes of the trace run.
2693 Query the current status of a tracepoint.
2697 Query the minimum length of instruction at which a fast tracepoint may
2700 * Dcache size (number of lines) and line-size are now runtime-configurable
2701 via "set dcache line" and "set dcache line-size" commands.
2705 Texas Instruments TMS320C6x tic6x-*-*
2709 Renesas RL78 rl78-*-elf
2711 *** Changes in GDB 7.3.1
2713 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2715 *** Changes in GDB 7.3
2717 * GDB has a new command: "thread find [REGEXP]".
2718 It finds the thread id whose name, target id, or thread extra info
2719 matches the given regular expression.
2721 * The "catch syscall" command now works on mips*-linux* targets.
2723 * The -data-disassemble MI command now supports modes 2 and 3 for
2724 dumping the instruction opcodes.
2726 * New command line options
2728 -data-directory DIR Specify DIR as the "data-directory".
2729 This is mostly for testing purposes.
2731 * The "maint set python auto-load on|off" command has been renamed to
2732 "set auto-load-scripts on|off".
2734 * GDB has a new command: "set directories".
2735 It is like the "dir" command except that it replaces the
2736 source path list instead of augmenting it.
2738 * GDB now understands thread names.
2740 On GNU/Linux, "info threads" will display the thread name as set by
2741 prctl or pthread_setname_np.
2743 There is also a new command, "thread name", which can be used to
2744 assign a name internally for GDB to display.
2747 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2748 has been integrated into GDB.
2752 ** The function gdb.Write now accepts an optional keyword 'stream'.
2753 This keyword, when provided, will direct the output to either
2754 stdout, stderr, or GDB's logging output.
2756 ** Parameters can now be be sub-classed in Python, and in particular
2757 you may implement the get_set_doc and get_show_doc functions.
2758 This improves how Parameter set/show documentation is processed
2759 and allows for more dynamic content.
2761 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2762 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2763 have an is_valid method.
2765 ** Breakpoints can now be sub-classed in Python, and in particular
2766 you may implement a 'stop' function that is executed each time
2767 the inferior reaches that breakpoint.
2769 ** New function gdb.lookup_global_symbol looks up a global symbol.
2771 ** GDB values in Python are now callable if the value represents a
2772 function. For example, if 'some_value' represents a function that
2773 takes two integer parameters and returns a value, you can call
2774 that function like so:
2776 result = some_value (10,20)
2778 ** Module gdb.types has been added.
2779 It contains a collection of utilities for working with gdb.Types objects:
2780 get_basic_type, has_field, make_enum_dict.
2782 ** Module gdb.printing has been added.
2783 It contains utilities for writing and registering pretty-printers.
2784 New classes: PrettyPrinter, SubPrettyPrinter,
2785 RegexpCollectionPrettyPrinter.
2786 New function: register_pretty_printer.
2788 ** New commands "info pretty-printers", "enable pretty-printer" and
2789 "disable pretty-printer" have been added.
2791 ** gdb.parameter("directories") is now available.
2793 ** New function gdb.newest_frame returns the newest frame in the
2796 ** The gdb.InferiorThread class has a new "name" attribute. This
2797 holds the thread's name.
2799 ** Python Support for Inferior events.
2800 Python scripts can add observers to be notified of events
2801 occurring in the process being debugged.
2802 The following events are currently supported:
2803 - gdb.events.cont Continue event.
2804 - gdb.events.exited Inferior exited event.
2805 - gdb.events.stop Signal received, and Breakpoint hit events.
2809 ** GDB now puts template parameters in scope when debugging in an
2810 instantiation. For example, if you have:
2812 template<int X> int func (void) { return X; }
2814 then if you step into func<5>, "print X" will show "5". This
2815 feature requires proper debuginfo support from the compiler; it
2816 was added to GCC 4.5.
2818 ** The motion commands "next", "finish", "until", and "advance" now
2819 work better when exceptions are thrown. In particular, GDB will
2820 no longer lose control of the inferior; instead, the GDB will
2821 stop the inferior at the point at which the exception is caught.
2822 This functionality requires a change in the exception handling
2823 code that was introduced in GCC 4.5.
2825 * GDB now follows GCC's rules on accessing volatile objects when
2826 reading or writing target state during expression evaluation.
2827 One notable difference to prior behavior is that "print x = 0"
2828 no longer generates a read of x; the value of the assignment is
2829 now always taken directly from the value being assigned.
2831 * GDB now has some support for using labels in the program's source in
2832 linespecs. For instance, you can use "advance label" to continue
2833 execution to a label.
2835 * GDB now has support for reading and writing a new .gdb_index
2836 section. This section holds a fast index of DWARF debugging
2837 information and can be used to greatly speed up GDB startup and
2838 operation. See the documentation for `save gdb-index' for details.
2840 * The "watch" command now accepts an optional "-location" argument.
2841 When used, this causes GDB to watch the memory referred to by the
2842 expression. Such a watchpoint is never deleted due to it going out
2845 * GDB now supports thread debugging of core dumps on GNU/Linux.
2847 GDB now activates thread debugging using the libthread_db library
2848 when debugging GNU/Linux core dumps, similarly to when debugging
2849 live processes. As a result, when debugging a core dump file, GDB
2850 is now able to display pthread_t ids of threads. For example, "info
2851 threads" shows the same output as when debugging the process when it
2852 was live. In earlier releases, you'd see something like this:
2855 * 1 LWP 6780 main () at main.c:10
2857 While now you see this:
2860 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2862 It is also now possible to inspect TLS variables when debugging core
2865 When debugging a core dump generated on a machine other than the one
2866 used to run GDB, you may need to point GDB at the correct
2867 libthread_db library with the "set libthread-db-search-path"
2868 command. See the user manual for more details on this command.
2870 * When natively debugging programs on PowerPC BookE processors running
2871 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2872 which stop execution of the inferior whenever it executes an instruction
2873 at any address within the specified range. See the "PowerPC Embedded"
2874 section in the user manual for more details.
2876 * New features in the GDB remote stub, GDBserver
2878 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2879 and i686 LynxOS (version 5.x).
2881 ** GDBserver is now supported on Blackfin Linux.
2883 * New native configurations
2885 ia64 HP-UX ia64-*-hpux*
2889 Analog Devices, Inc. Blackfin Processor bfin-*
2891 * Ada task switching is now supported on sparc-elf targets when
2892 debugging a program using the Ravenscar Profile. For more information,
2893 see the "Tasking Support when using the Ravenscar Profile" section
2894 in the GDB user manual.
2896 * Guile support was removed.
2898 * New features in the GNU simulator
2900 ** The --map-info flag lists all known core mappings.
2902 ** CFI flashes may be simulated via the "cfi" device.
2904 *** Changes in GDB 7.2
2906 * Shared library support for remote targets by default
2908 When GDB is configured for a generic, non-OS specific target, like
2909 for example, --target=arm-eabi or one of the many *-*-elf targets,
2910 GDB now queries remote stubs for loaded shared libraries using the
2911 `qXfer:libraries:read' packet. Previously, shared library support
2912 was always disabled for such configurations.
2916 ** Argument Dependent Lookup (ADL)
2918 In C++ ADL lookup directs function search to the namespaces of its
2919 arguments even if the namespace has not been imported.
2929 Here the compiler will search for `foo' in the namespace of 'b'
2930 and find A::foo. GDB now supports this. This construct is commonly
2931 used in the Standard Template Library for operators.
2933 ** Improved User Defined Operator Support
2935 In addition to member operators, GDB now supports lookup of operators
2936 defined in a namespace and imported with a `using' directive, operators
2937 defined in the global scope, operators imported implicitly from an
2938 anonymous namespace, and the ADL operators mentioned in the previous
2940 GDB now also supports proper overload resolution for all the previously
2941 mentioned flavors of operators.
2943 ** static const class members
2945 Printing of static const class members that are initialized in the
2946 class definition has been fixed.
2948 * Windows Thread Information Block access.
2950 On Windows targets, GDB now supports displaying the Windows Thread
2951 Information Block (TIB) structure. This structure is visible either
2952 by using the new command `info w32 thread-information-block' or, by
2953 dereferencing the new convenience variable named `$_tlb', a
2954 thread-specific pointer to the TIB. This feature is also supported
2955 when remote debugging using GDBserver.
2957 * Static tracepoints
2959 Static tracepoints are calls in the user program into a tracing
2960 library. One such library is a port of the LTTng kernel tracer to
2961 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2962 When debugging with GDBserver, GDB now supports combining the GDB
2963 tracepoint machinery with such libraries. For example: the user can
2964 use GDB to probe a static tracepoint marker (a call from the user
2965 program into the tracing library) with the new "strace" command (see
2966 "New commands" below). This creates a "static tracepoint" in the
2967 breakpoint list, that can be manipulated with the same feature set
2968 as fast and regular tracepoints. E.g., collect registers, local and
2969 global variables, collect trace state variables, and define
2970 tracepoint conditions. In addition, the user can collect extra
2971 static tracepoint marker specific data, by collecting the new
2972 $_sdata internal variable. When analyzing the trace buffer, you can
2973 inspect $_sdata like any other variable available to GDB. For more
2974 information, see the "Tracepoints" chapter in GDB user manual. New
2975 remote packets have been defined to support static tracepoints, see
2976 the "New remote packets" section below.
2978 * Better reconstruction of tracepoints after disconnected tracing
2980 GDB will attempt to download the original source form of tracepoint
2981 definitions when starting a trace run, and then will upload these
2982 upon reconnection to the target, resulting in a more accurate
2983 reconstruction of the tracepoints that are in use on the target.
2987 You can now exercise direct control over the ways that GDB can
2988 affect your program. For instance, you can disallow the setting of
2989 breakpoints, so that the program can run continuously (assuming
2990 non-stop mode). In addition, the "observer" variable is available
2991 to switch all of the different controls; in observer mode, GDB
2992 cannot affect the target's behavior at all, which is useful for
2993 tasks like diagnosing live systems in the field.
2995 * The new convenience variable $_thread holds the number of the
2998 * New remote packets
3002 Return the address of the Windows Thread Information Block of a given thread.
3006 In response to several of the tracepoint packets, the target may now
3007 also respond with a number of intermediate `qRelocInsn' request
3008 packets before the final result packet, to have GDB handle
3009 relocating an instruction to execute at a different address. This
3010 is particularly useful for stubs that support fast tracepoints. GDB
3011 reports support for this feature in the qSupported packet.
3015 List static tracepoint markers in the target program.
3019 List static tracepoint markers at a given address in the target
3022 qXfer:statictrace:read
3024 Read the static trace data collected (by a `collect $_sdata'
3025 tracepoint action). The remote stub reports support for this packet
3026 to gdb's qSupported query.
3030 Send the current settings of GDB's permission flags.
3034 Send part of the source (textual) form of a tracepoint definition,
3035 which includes location, conditional, and action list.
3037 * The source command now accepts a -s option to force searching for the
3038 script in the source search path even if the script name specifies
3041 * New features in the GDB remote stub, GDBserver
3043 - GDBserver now support tracepoints (including fast tracepoints, and
3044 static tracepoints). The feature is currently supported by the
3045 i386-linux and amd64-linux builds. See the "Tracepoints support
3046 in gdbserver" section in the manual for more information.
3048 GDBserver JIT compiles the tracepoint's conditional agent
3049 expression bytecode into native code whenever possible for low
3050 overhead dynamic tracepoints conditionals. For such tracepoints,
3051 an expression that examines program state is evaluated when the
3052 tracepoint is reached, in order to determine whether to capture
3053 trace data. If the condition is simple and false, processing the
3054 tracepoint finishes very quickly and no data is gathered.
3056 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3057 for static tracepoints support.
3059 - GDBserver now supports x86_64 Windows 64-bit debugging.
3061 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3062 it understands register description.
3064 * The --batch flag now disables pagination and queries.
3066 * X86 general purpose registers
3068 GDB now supports reading/writing byte, word and double-word x86
3069 general purpose registers directly. This means you can use, say,
3070 $ah or $ax to refer, respectively, to the byte register AH and
3071 16-bit word register AX that are actually portions of the 32-bit
3072 register EAX or 64-bit register RAX.
3074 * The `commands' command now accepts a range of breakpoints to modify.
3075 A plain `commands' following a command that creates multiple
3076 breakpoints affects all the breakpoints set by that command. This
3077 applies to breakpoints set by `rbreak', and also applies when a
3078 single `break' command creates multiple breakpoints (e.g.,
3079 breakpoints on overloaded c++ functions).
3081 * The `rbreak' command now accepts a filename specification as part of
3082 its argument, limiting the functions selected by the regex to those
3083 in the specified file.
3085 * Support for remote debugging Windows and SymbianOS shared libraries
3086 from Unix hosts has been improved. Non Windows GDB builds now can
3087 understand target reported file names that follow MS-DOS based file
3088 system semantics, such as file names that include drive letters and
3089 use the backslash character as directory separator. This makes it
3090 possible to transparently use the "set sysroot" and "set
3091 solib-search-path" on Unix hosts to point as host copies of the
3092 target's shared libraries. See the new command "set
3093 target-file-system-kind" described below, and the "Commands to
3094 specify files" section in the user manual for more information.
3098 eval template, expressions...
3099 Convert the values of one or more expressions under the control
3100 of the string template to a command line, and call it.
3102 set target-file-system-kind unix|dos-based|auto
3103 show target-file-system-kind
3104 Set or show the assumed file system kind for target reported file
3107 save breakpoints <filename>
3108 Save all current breakpoint definitions to a file suitable for use
3109 in a later debugging session. To read the saved breakpoint
3110 definitions, use the `source' command.
3112 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3115 info static-tracepoint-markers
3116 Display information about static tracepoint markers in the target.
3118 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3119 Define a static tracepoint by probing a marker at the given
3120 function, line, address, or marker ID.
3124 Enable and disable observer mode.
3126 set may-write-registers on|off
3127 set may-write-memory on|off
3128 set may-insert-breakpoints on|off
3129 set may-insert-tracepoints on|off
3130 set may-insert-fast-tracepoints on|off
3131 set may-interrupt on|off
3132 Set individual permissions for GDB effects on the target. Note that
3133 some of these settings can have undesirable or surprising
3134 consequences, particularly when changed in the middle of a session.
3135 For instance, disabling the writing of memory can prevent
3136 breakpoints from being inserted, cause single-stepping to fail, or
3137 even crash your program, if you disable after breakpoints have been
3138 inserted. However, GDB should not crash.
3140 set record memory-query on|off
3141 show record memory-query
3142 Control whether to stop the inferior if memory changes caused
3143 by an instruction cannot be recorded.
3148 The disassemble command now supports "start,+length" form of two arguments.
3152 ** GDB now provides a new directory location, called the python directory,
3153 where Python scripts written for GDB can be installed. The location
3154 of that directory is <data-directory>/python, where <data-directory>
3155 is the GDB data directory. For more details, see section `Scripting
3156 GDB using Python' in the manual.
3158 ** The GDB Python API now has access to breakpoints, symbols, symbol
3159 tables, program spaces, inferiors, threads and frame's code blocks.
3160 Additionally, GDB Parameters can now be created from the API, and
3161 manipulated via set/show in the CLI.
3163 ** New functions gdb.target_charset, gdb.target_wide_charset,
3164 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3166 ** New exception gdb.GdbError.
3168 ** Pretty-printers are now also looked up in the current program space.
3170 ** Pretty-printers can now be individually enabled and disabled.
3172 ** GDB now looks for names of Python scripts to auto-load in a
3173 special section named `.debug_gdb_scripts', in addition to looking
3174 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3176 * Tracepoint actions were unified with breakpoint commands. In particular,
3177 there are no longer differences in "info break" output for breakpoints and
3178 tracepoints and the "commands" command can be used for both tracepoints and
3179 regular breakpoints.
3183 ARM Symbian arm*-*-symbianelf*
3185 * D language support.
3186 GDB now supports debugging programs written in the D programming
3189 * GDB now supports the extended ptrace interface for PowerPC which is
3190 available since Linux kernel version 2.6.34. This automatically enables
3191 any hardware breakpoints and additional hardware watchpoints available in
3192 the processor. The old ptrace interface exposes just one hardware
3193 watchpoint and no hardware breakpoints.
3195 * GDB is now able to use the Data Value Compare (DVC) register available on
3196 embedded PowerPC processors to implement in hardware simple watchpoint
3197 conditions of the form:
3199 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3201 This works in native GDB running on Linux kernels with the extended ptrace
3202 interface mentioned above.
3204 *** Changes in GDB 7.1
3208 ** Namespace Support
3210 GDB now supports importing of namespaces in C++. This enables the
3211 user to inspect variables from imported namespaces. Support for
3212 namepace aliasing has also been added. So, if a namespace is
3213 aliased in the current scope (e.g. namepace C=A; ) the user can
3214 print variables using the alias (e.g. (gdb) print C::x).
3218 All known bugs relating to the printing of virtual base class were
3219 fixed. It is now possible to call overloaded static methods using a
3224 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3225 and reinterpret_cast<> are now handled by the C++ expression parser.
3229 Xilinx MicroBlaze microblaze-*-*
3234 Xilinx MicroBlaze microblaze
3237 * Multi-program debugging.
3239 GDB now has support for multi-program (a.k.a. multi-executable or
3240 multi-exec) debugging. This allows for debugging multiple inferiors
3241 simultaneously each running a different program under the same GDB
3242 session. See "Debugging Multiple Inferiors and Programs" in the
3243 manual for more information. This implied some user visible changes
3244 in the multi-inferior support. For example, "info inferiors" now
3245 lists inferiors that are not running yet or that have exited
3246 already. See also "New commands" and "New options" below.
3248 * New tracing features
3250 GDB's tracepoint facility now includes several new features:
3252 ** Trace state variables
3254 GDB tracepoints now include support for trace state variables, which
3255 are variables managed by the target agent during a tracing
3256 experiment. They are useful for tracepoints that trigger each
3257 other, so for instance one tracepoint can count hits in a variable,
3258 and then a second tracepoint has a condition that is true when the
3259 count reaches a particular value. Trace state variables share the
3260 $-syntax of GDB convenience variables, and can appear in both
3261 tracepoint actions and condition expressions. Use the "tvariable"
3262 command to create, and "info tvariables" to view; see "Trace State
3263 Variables" in the manual for more detail.
3267 GDB now includes an option for defining fast tracepoints, which
3268 targets may implement more efficiently, such as by installing a jump
3269 into the target agent rather than a trap instruction. The resulting
3270 speedup can be by two orders of magnitude or more, although the
3271 tradeoff is that some program locations on some target architectures
3272 might not allow fast tracepoint installation, for instance if the
3273 instruction to be replaced is shorter than the jump. To request a
3274 fast tracepoint, use the "ftrace" command, with syntax identical to
3275 the regular trace command.
3277 ** Disconnected tracing
3279 It is now possible to detach GDB from the target while it is running
3280 a trace experiment, then reconnect later to see how the experiment
3281 is going. In addition, a new variable disconnected-tracing lets you
3282 tell the target agent whether to continue running a trace if the
3283 connection is lost unexpectedly.
3287 GDB now has the ability to save the trace buffer into a file, and
3288 then use that file as a target, similarly to you can do with
3289 corefiles. You can select trace frames, print data that was
3290 collected in them, and use tstatus to display the state of the
3291 tracing run at the moment that it was saved. To create a trace
3292 file, use "tsave <filename>", and to use it, do "target tfile
3295 ** Circular trace buffer
3297 You can ask the target agent to handle the trace buffer as a
3298 circular buffer, discarding the oldest trace frames to make room for
3299 newer ones, by setting circular-trace-buffer to on. This feature may
3300 not be available for all target agents.
3305 The disassemble command, when invoked with two arguments, now requires
3306 the arguments to be comma-separated.
3309 The info variables command now displays variable definitions. Files
3310 which only declare a variable are not shown.
3313 The source command is now capable of sourcing Python scripts.
3314 This feature is dependent on the debugger being build with Python
3317 Related to this enhancement is also the introduction of a new command
3318 "set script-extension" (see below).
3320 * New commands (for set/show, see "New options" below)
3322 record save [<FILENAME>]
3323 Save a file (in core file format) containing the process record
3324 execution log for replay debugging at a later time.
3326 record restore <FILENAME>
3327 Restore the process record execution log that was saved at an
3328 earlier time, for replay debugging.
3330 add-inferior [-copies <N>] [-exec <FILENAME>]
3333 clone-inferior [-copies <N>] [ID]
3334 Make a new inferior ready to execute the same program another
3335 inferior has loaded.
3340 maint info program-spaces
3341 List the program spaces loaded into GDB.
3343 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3344 show remote interrupt-sequence
3345 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3346 as the sequence to the remote target in order to interrupt the execution.
3347 Ctrl-C is a default. Some system prefers BREAK which is high level of
3348 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3349 Magic SysRq g. It is BREAK signal and character 'g'.
3351 set remote interrupt-on-connect [on | off]
3352 show remote interrupt-on-connect
3353 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3354 remote target when gdb connects to it. This is needed when you debug
3357 set remotebreak [on | off]
3359 Deprecated. Use "set/show remote interrupt-sequence" instead.
3361 tvariable $NAME [ = EXP ]
3362 Create or modify a trace state variable.
3365 List trace state variables and their values.
3367 delete tvariable $NAME ...
3368 Delete one or more trace state variables.
3371 Evaluate the given expressions without collecting anything into the
3372 trace buffer. (Valid in tracepoint actions only.)
3374 ftrace FN / FILE:LINE / *ADDR
3375 Define a fast tracepoint at the given function, line, or address.
3377 * New expression syntax
3379 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3380 GDB now parses 0b101010 identically with 42.
3384 set follow-exec-mode new|same
3385 show follow-exec-mode
3386 Control whether GDB reuses the same inferior across an exec call or
3387 creates a new one. This is useful to be able to restart the old
3388 executable after the inferior having done an exec call.
3390 set default-collect EXPR, ...
3391 show default-collect
3392 Define a list of expressions to be collected at each tracepoint.
3393 This is a useful way to ensure essential items are not overlooked,
3394 such as registers or a critical global variable.
3396 set disconnected-tracing
3397 show disconnected-tracing
3398 If set to 1, the target is instructed to continue tracing if it
3399 loses its connection to GDB. If 0, the target is to stop tracing
3402 set circular-trace-buffer
3403 show circular-trace-buffer
3404 If set to on, the target is instructed to use a circular trace buffer
3405 and discard the oldest trace frames instead of stopping the trace due
3406 to a full trace buffer. If set to off, the trace stops when the buffer
3407 fills up. Some targets may not support this.
3409 set script-extension off|soft|strict
3410 show script-extension
3411 If set to "off", the debugger does not perform any script language
3412 recognition, and all sourced files are assumed to be GDB scripts.
3413 If set to "soft" (the default), files are sourced according to
3414 filename extension, falling back to GDB scripts if the first
3416 If set to "strict", files are sourced according to filename extension.
3418 set ada trust-PAD-over-XVS on|off
3419 show ada trust-PAD-over-XVS
3420 If off, activate a workaround against a bug in the debugging information
3421 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3422 the GCC sources for more information about the GNAT encoding and
3423 PAD types in particular). It is always safe to set this option to
3424 off, but this introduces a slight performance penalty. The default
3427 * Python API Improvements
3429 ** GDB provides the new class gdb.LazyString. This is useful in
3430 some pretty-printing cases. The new method gdb.Value.lazy_string
3431 provides a simple way to create objects of this type.
3433 ** The fields returned by gdb.Type.fields now have an
3434 `is_base_class' attribute.
3436 ** The new method gdb.Type.range returns the range of an array type.
3438 ** The new method gdb.parse_and_eval can be used to parse and
3439 evaluate an expression.
3441 * New remote packets
3444 Define a trace state variable.
3447 Get the current value of a trace state variable.
3450 Set desired tracing behavior upon disconnection.
3453 Set the trace buffer to be linear or circular.
3456 Get data about the tracepoints currently in use.
3460 Process record now works correctly with hardware watchpoints.
3462 Multiple bug fixes have been made to the mips-irix port, making it
3463 much more reliable. In particular:
3464 - Debugging threaded applications is now possible again. Previously,
3465 GDB would hang while starting the program, or while waiting for
3466 the program to stop at a breakpoint.
3467 - Attaching to a running process no longer hangs.
3468 - An error occurring while loading a core file has been fixed.
3469 - Changing the value of the PC register now works again. This fixes
3470 problems observed when using the "jump" command, or when calling
3471 a function from GDB, or even when assigning a new value to $pc.
3472 - With the "finish" and "return" commands, the return value for functions
3473 returning a small array is now correctly printed.
3474 - It is now possible to break on shared library code which gets executed
3475 during a shared library init phase (code executed while executing
3476 their .init section). Previously, the breakpoint would have no effect.
3477 - GDB is now able to backtrace through the signal handler for
3478 non-threaded programs.
3480 PIE (Position Independent Executable) programs debugging is now supported.
3481 This includes debugging execution of PIC (Position Independent Code) shared
3482 libraries although for that, it should be possible to run such libraries as an
3485 *** Changes in GDB 7.0
3487 * GDB now has an interface for JIT compilation. Applications that
3488 dynamically generate code can create symbol files in memory and register
3489 them with GDB. For users, the feature should work transparently, and
3490 for JIT developers, the interface is documented in the GDB manual in the
3491 "JIT Compilation Interface" chapter.
3493 * Tracepoints may now be conditional. The syntax is as for
3494 breakpoints; either an "if" clause appended to the "trace" command,
3495 or the "condition" command is available. GDB sends the condition to
3496 the target for evaluation using the same bytecode format as is used
3497 for tracepoint actions.
3499 * The disassemble command now supports: an optional /r modifier, print the
3500 raw instructions in hex as well as in symbolic form, and an optional /m
3501 modifier to print mixed source+assembly.
3503 * Process record and replay
3505 In a architecture environment that supports ``process record and
3506 replay'', ``process record and replay'' target can record a log of
3507 the process execution, and replay it with both forward and reverse
3510 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3511 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3512 set execution-direction {forward|reverse}, for targets that support
3515 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3516 feature is available with a native GDB running on kernel version
3519 * GDB now has support for multi-byte and wide character sets on the
3520 target. Strings whose character type is wchar_t, char16_t, or
3521 char32_t are now correctly printed. GDB supports wide- and unicode-
3522 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3523 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3524 `printf'. This feature requires iconv to work properly; if your
3525 system does not have a working iconv, GDB can use GNU libiconv. See
3526 the installation instructions for more information.
3528 * GDB now supports automatic retrieval of shared library files from
3529 remote targets. To use this feature, specify a system root that begins
3530 with the `remote:' prefix, either via the `set sysroot' command or via
3531 the `--with-sysroot' configure-time option.
3533 * "info sharedlibrary" now takes an optional regex of libraries to show,
3534 and it now reports if a shared library has no debugging information.
3536 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3537 now complete on file names.
3539 * When completing in expressions, gdb will attempt to limit
3540 completions to allowable structure or union fields, where appropriate.
3541 For instance, consider:
3543 # struct example { int f1; double f2; };
3544 # struct example variable;
3547 If the user types TAB at the end of this command line, the available
3548 completions will be "f1" and "f2".
3550 * Inlined functions are now supported. They show up in backtraces, and
3551 the "step", "next", and "finish" commands handle them automatically.
3553 * GDB now supports the token-splicing (##) and stringification (#)
3554 operators when expanding macros. It also supports variable-arity
3557 * GDB now supports inspecting extra signal information, exported by
3558 the new $_siginfo convenience variable. The feature is currently
3559 implemented on linux ARM, i386 and amd64.
3561 * GDB can now display the VFP floating point registers and NEON vector
3562 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3563 can provide these registers (requires Linux 2.6.30 or later). Remote
3564 and simulator targets may also provide them.
3566 * New remote packets
3569 Search memory for a sequence of bytes.
3572 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3573 operation over reliable transport links. Use of this packet is
3574 controlled by the `set remote noack-packet' command.
3577 Kill the process with the specified process ID. Use this in preference
3578 to `k' when multiprocess protocol extensions are supported.
3581 Obtains additional operating system information
3585 Read or write additional signal information.
3587 * Removed remote protocol undocumented extension
3589 An undocumented extension to the remote protocol's `S' stop reply
3590 packet that permited the stub to pass a process id was removed.
3591 Remote servers should use the `T' stop reply packet instead.
3593 * GDB now supports multiple function calling conventions according to the
3594 DWARF-2 DW_AT_calling_convention function attribute.
3596 * The SH target utilizes the aforementioned change to distinguish between gcc
3597 and Renesas calling convention. It also adds the new CLI commands
3598 `set/show sh calling-convention'.
3600 * GDB can now read compressed debug sections, as produced by GNU gold
3601 with the --compress-debug-sections=zlib flag.
3603 * 64-bit core files are now supported on AIX.
3605 * Thread switching is now supported on Tru64.
3607 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3608 which will be allocated using malloc later in program execution.
3610 * The qXfer:libraries:read remote procotol packet now allows passing a
3611 list of section offsets.
3613 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3614 conditions handling signals delivered during attach or thread creation
3615 have also been fixed.
3617 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3618 From the user's standpoint, all unqualified instances of True and False
3619 are treated as the standard definitions, regardless of context.
3621 * GDB now parses C++ symbol and type names more flexibly. For
3624 template<typename T> class C { };
3627 GDB will now correctly handle all of:
3629 ptype C<char const *>
3630 ptype C<char const*>
3631 ptype C<const char *>
3632 ptype C<const char*>
3634 * New features in the GDB remote stub, gdbserver
3636 - The "--wrapper" command-line argument tells gdbserver to use a
3637 wrapper program to launch programs for debugging.
3639 - On PowerPC and S/390 targets, it is now possible to use a single
3640 gdbserver executable to debug both 32-bit and 64-bit programs.
3641 (This requires gdbserver itself to be built as a 64-bit executable.)
3643 - gdbserver uses the new noack protocol mode for TCP connections to
3644 reduce communications latency, if also supported and enabled in GDB.
3646 - Support for the sparc64-linux-gnu target is now included in
3649 - The amd64-linux build of gdbserver now supports debugging both
3650 32-bit and 64-bit programs.
3652 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3653 now support hardware watchpoints, and will use them automatically
3658 GDB now has support for scripting using Python. Whether this is
3659 available is determined at configure time.
3661 New GDB commands can now be written in Python.
3663 * Ada tasking support
3665 Ada tasks can now be inspected in GDB. The following commands have
3669 Print the list of Ada tasks.
3671 Print detailed information about task number N.
3673 Print the task number of the current task.
3675 Switch the context of debugging to task number N.
3677 * Support for user-defined prefixed commands. The "define" command can
3678 add new commands to existing prefixes, e.g. "target".
3680 * Multi-inferior, multi-process debugging.
3682 GDB now has generalized support for multi-inferior debugging. See
3683 "Debugging Multiple Inferiors" in the manual for more information.
3684 Although availability still depends on target support, the command
3685 set is more uniform now. The GNU/Linux specific multi-forks support
3686 has been migrated to this new framework. This implied some user
3687 visible changes; see "New commands" and also "Removed commands"
3690 * Target descriptions can now describe the target OS ABI. See the
3691 "Target Description Format" section in the user manual for more
3694 * Target descriptions can now describe "compatible" architectures
3695 to indicate that the target can execute applications for a different
3696 architecture in addition to those for the main target architecture.
3697 See the "Target Description Format" section in the user manual for
3700 * Multi-architecture debugging.
3702 GDB now includes general supports for debugging applications on
3703 hybrid systems that use more than one single processor architecture
3704 at the same time. Each such hybrid architecture still requires
3705 specific support to be added. The only hybrid architecture supported
3706 in this version of GDB is the Cell Broadband Engine.
3708 * GDB now supports integrated debugging of Cell/B.E. applications that
3709 use both the PPU and SPU architectures. To enable support for hybrid
3710 Cell/B.E. debugging, you need to configure GDB to support both the
3711 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3712 --enable-targets configure option.
3714 * Non-stop mode debugging.
3716 For some targets, GDB now supports an optional mode of operation in
3717 which you can examine stopped threads while other threads continue
3718 to execute freely. This is referred to as non-stop mode, with the
3719 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3720 section in the user manual for more information.
3722 To be able to support remote non-stop debugging, a remote stub needs
3723 to implement the non-stop mode remote protocol extensions, as
3724 described in the "Remote Non-Stop" section of the user manual. The
3725 GDB remote stub, gdbserver, has been adjusted to support these
3726 extensions on linux targets.
3728 * New commands (for set/show, see "New options" below)
3730 catch syscall [NAME(S) | NUMBER(S)]
3731 Catch system calls. Arguments, which should be names of system
3732 calls or their numbers, mean catch only those syscalls. Without
3733 arguments, every syscall will be caught. When the inferior issues
3734 any of the specified syscalls, GDB will stop and announce the system
3735 call, both when it is called and when its call returns. This
3736 feature is currently available with a native GDB running on the
3737 Linux Kernel, under the following architectures: x86, x86_64,
3738 PowerPC and PowerPC64.
3740 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3742 Search memory for a sequence of bytes.
3744 maint set python print-stack
3745 maint show python print-stack
3746 Show a stack trace when an error is encountered in a Python script.
3749 Invoke CODE by passing it to the Python interpreter.
3754 These allow macros to be defined, undefined, and listed
3758 Show operating system information about processes.
3761 List the inferiors currently under GDB's control.
3764 Switch focus to inferior number NUM.
3767 Detach from inferior number NUM.
3770 Kill inferior number NUM.
3774 set spu stop-on-load
3775 show spu stop-on-load
3776 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3778 set spu auto-flush-cache
3779 show spu auto-flush-cache
3780 Control whether to automatically flush the software-managed cache
3781 during Cell/B.E. debugging.
3783 set sh calling-convention
3784 show sh calling-convention
3785 Control the calling convention used when calling SH target functions.
3788 show debug timestamp
3789 Control display of timestamps with GDB debugging output.
3791 set disassemble-next-line
3792 show disassemble-next-line
3793 Control display of disassembled source lines or instructions when
3796 set remote noack-packet
3797 show remote noack-packet
3798 Set/show the use of remote protocol QStartNoAckMode packet. See above
3799 under "New remote packets."
3801 set remote query-attached-packet
3802 show remote query-attached-packet
3803 Control use of remote protocol `qAttached' (query-attached) packet.
3805 set remote read-siginfo-object
3806 show remote read-siginfo-object
3807 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3810 set remote write-siginfo-object
3811 show remote write-siginfo-object
3812 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3815 set remote reverse-continue
3816 show remote reverse-continue
3817 Control use of remote protocol 'bc' (reverse-continue) packet.
3819 set remote reverse-step
3820 show remote reverse-step
3821 Control use of remote protocol 'bs' (reverse-step) packet.
3823 set displaced-stepping
3824 show displaced-stepping
3825 Control displaced stepping mode. Displaced stepping is a way to
3826 single-step over breakpoints without removing them from the debuggee.
3827 Also known as "out-of-line single-stepping".
3830 show debug displaced
3831 Control display of debugging info for displaced stepping.
3833 maint set internal-error
3834 maint show internal-error
3835 Control what GDB does when an internal error is detected.
3837 maint set internal-warning
3838 maint show internal-warning
3839 Control what GDB does when an internal warning is detected.
3844 Use a wrapper program to launch programs for debugging.
3846 set multiple-symbols (all|ask|cancel)
3847 show multiple-symbols
3848 The value of this variable can be changed to adjust the debugger behavior
3849 when an expression or a breakpoint location contains an ambiguous symbol
3850 name (an overloaded function name, for instance).
3852 set breakpoint always-inserted
3853 show breakpoint always-inserted
3854 Keep breakpoints always inserted in the target, as opposed to inserting
3855 them when resuming the target, and removing them when the target stops.
3856 This option can improve debugger performance on slow remote targets.
3858 set arm fallback-mode (arm|thumb|auto)
3859 show arm fallback-mode
3860 set arm force-mode (arm|thumb|auto)
3862 These commands control how ARM GDB determines whether instructions
3863 are ARM or Thumb. The default for both settings is auto, which uses
3864 the current CPSR value for instructions without symbols; previous
3865 versions of GDB behaved as if "set arm fallback-mode arm".
3867 set disable-randomization
3868 show disable-randomization
3869 Standalone programs run with the virtual address space randomization enabled
3870 by default on some platforms. This option keeps the addresses stable across
3871 multiple debugging sessions.
3875 Control whether other threads are stopped or not when some thread hits
3880 Requests that asynchronous execution is enabled in the target, if available.
3881 In this case, it's possible to resume target in the background, and interact
3882 with GDB while the target is running. "show target-async" displays the
3883 current state of asynchronous execution of the target.
3885 set target-wide-charset
3886 show target-wide-charset
3887 The target-wide-charset is the name of the character set that GDB
3888 uses when printing characters whose type is wchar_t.
3890 set tcp auto-retry (on|off)
3892 set tcp connect-timeout
3893 show tcp connect-timeout
3894 These commands allow GDB to retry failed TCP connections to a remote stub
3895 with a specified timeout period; this is useful if the stub is launched
3896 in parallel with GDB but may not be ready to accept connections immediately.
3898 set libthread-db-search-path
3899 show libthread-db-search-path
3900 Control list of directories which GDB will search for appropriate
3903 set schedule-multiple (on|off)
3904 show schedule-multiple
3905 Allow GDB to resume all threads of all processes or only threads of
3906 the current process.
3910 Use more aggressive caching for accesses to the stack. This improves
3911 performance of remote debugging (particularly backtraces) without
3912 affecting correctness.
3914 set interactive-mode (on|off|auto)
3915 show interactive-mode
3916 Control whether GDB runs in interactive mode (on) or not (off).
3917 When in interactive mode, GDB waits for the user to answer all
3918 queries. Otherwise, GDB does not wait and assumes the default
3919 answer. When set to auto (the default), GDB determines which
3920 mode to use based on the stdin settings.
3925 For program forks, this is replaced by the new more generic `info
3926 inferiors' command. To list checkpoints, you can still use the
3927 `info checkpoints' command, which was an alias for the `info forks'
3931 Replaced by the new `inferior' command. To switch between
3932 checkpoints, you can still use the `restart' command, which was an
3933 alias for the `fork' command.
3936 This is removed, since some targets don't have a notion of
3937 processes. To switch between processes, you can still use the
3938 `inferior' command using GDB's own inferior number.
3941 For program forks, this is replaced by the new more generic `kill
3942 inferior' command. To delete a checkpoint, you can still use the
3943 `delete checkpoint' command, which was an alias for the `delete
3947 For program forks, this is replaced by the new more generic `detach
3948 inferior' command. To detach a checkpoint, you can still use the
3949 `detach checkpoint' command, which was an alias for the `detach
3952 * New native configurations
3954 x86/x86_64 Darwin i[34567]86-*-darwin*
3956 x86_64 MinGW x86_64-*-mingw*
3960 Lattice Mico32 lm32-*
3961 x86 DICOS i[34567]86-*-dicos*
3962 x86_64 DICOS x86_64-*-dicos*
3965 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3966 (mingw32ce) debugging.
3972 These commands were actually not implemented on any target.
3974 *** Changes in GDB 6.8
3976 * New native configurations
3978 NetBSD/hppa hppa*-*netbsd*
3979 Xtensa GNU/Linux xtensa*-*-linux*
3983 NetBSD/hppa hppa*-*-netbsd*
3984 Xtensa GNU/Lunux xtensa*-*-linux*
3986 * Change in command line behavior -- corefiles vs. process ids.
3988 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3989 attaching to process NUMBER fails, GDB no longer attempts to open a
3990 core file named NUMBER. Attaching to a program using the -c option
3991 is no longer supported. Instead, use the '-p' or '--pid' options.
3993 * GDB can now be built as a native debugger for debugging Windows x86
3994 (mingw32) Portable Executable (PE) programs.
3996 * Pending breakpoints no longer change their number when their address
3999 * GDB now supports breakpoints with multiple locations,
4000 including breakpoints on C++ constructors, inside C++ templates,
4001 and in inlined functions.
4003 * GDB's ability to debug optimized code has been improved. GDB more
4004 accurately identifies function bodies and lexical blocks that occupy
4005 more than one contiguous range of addresses.
4007 * Target descriptions can now describe registers for PowerPC.
4009 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4010 registers on PowerPC targets.
4012 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4013 targets even when the libthread_db library is not available.
4015 * The GDB remote stub, gdbserver, now supports the new file transfer
4016 commands (remote put, remote get, and remote delete).
4018 * The GDB remote stub, gdbserver, now supports run and attach in
4019 extended-remote mode.
4021 * hppa*64*-*-hpux11* target broken
4022 The debugger is unable to start a program and fails with the following
4023 error: "Error trying to get information about dynamic linker".
4024 The gdb-6.7 release is also affected.
4026 * GDB now supports the --enable-targets= configure option to allow
4027 building a single GDB executable that supports multiple remote
4028 target architectures.
4030 * GDB now supports debugging C and C++ programs which use the
4031 Decimal Floating Point extension. In addition, the PowerPC target
4032 now has a set of pseudo-registers to inspect decimal float values
4033 stored in two consecutive float registers.
4035 * The -break-insert MI command can optionally create pending
4038 * Improved support for debugging Ada
4039 Many improvements to the Ada language support have been made. These
4041 - Better support for Ada2005 interface types
4042 - Improved handling of arrays and slices in general
4043 - Better support for Taft-amendment types
4044 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4046 - Improved command completion in Ada
4049 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4054 set print frame-arguments (all|scalars|none)
4055 show print frame-arguments
4056 The value of this variable can be changed to control which argument
4057 values should be printed by the debugger when displaying a frame.
4062 Transfer files to and from a remote target, and delete remote files.
4069 Transfer files to and from a remote target, and delete remote files.
4071 * New remote packets
4078 Open, close, read, write, and delete files on the remote system.
4081 Attach to an existing process on the remote system, in extended-remote
4085 Run a new process on the remote system, in extended-remote mode.
4087 *** Changes in GDB 6.7
4089 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4090 bfd, libiberty and opcodes, as revealed by static analysis donated by
4091 Coverity, Inc. (http://scan.coverity.com).
4093 * When looking up multiply-defined global symbols, GDB will now prefer the
4094 symbol definition in the current shared library if it was built using the
4095 -Bsymbolic linker option.
4097 * When the Text User Interface (TUI) is not configured, GDB will now
4098 recognize the -tui command-line option and print a message that the TUI
4101 * The GDB remote stub, gdbserver, now has lower overhead for high
4102 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4104 * GDB for MIPS targets now autodetects whether a remote target provides
4105 32-bit or 64-bit register values.
4107 * Support for C++ member pointers has been improved.
4109 * GDB now understands XML target descriptions, which specify the
4110 target's overall architecture. GDB can read a description from
4111 a local file or over the remote serial protocol.
4113 * Vectors of single-byte data use a new integer type which is not
4114 automatically displayed as character or string data.
4116 * The /s format now works with the print command. It displays
4117 arrays of single-byte integers and pointers to single-byte integers
4120 * Target descriptions can now describe target-specific registers,
4121 for architectures which have implemented the support (currently
4122 only ARM, M68K, and MIPS).
4124 * GDB and the GDB remote stub, gdbserver, now support the XScale
4127 * The GDB remote stub, gdbserver, has been updated to support
4128 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4129 has been rewritten to use the standard GDB remote protocol.
4131 * GDB can now step into C++ functions which are called through thunks.
4133 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4135 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4136 layout. It also supports a TextSeg= and DataSeg= response when only
4137 segment base addresses (rather than offsets) are available.
4139 * The /i format now outputs any trailing branch delay slot instructions
4140 immediately following the last instruction within the count specified.
4142 * The GDB remote protocol "T" stop reply packet now supports a
4143 "library" response. Combined with the new "qXfer:libraries:read"
4144 packet, this response allows GDB to debug shared libraries on targets
4145 where the operating system manages the list of loaded libraries (e.g.
4146 Windows and SymbianOS).
4148 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4149 (DLLs) on Windows and Windows CE targets.
4151 * GDB now supports a faster verification that a .debug file matches its binary
4152 according to its build-id signature, if the signature is present.
4158 Enable or disable hardware flow control (RTS/CTS) on the serial port
4159 when debugging using remote targets.
4161 set mem inaccessible-by-default
4162 show mem inaccessible-by-default
4163 If the target supplies a memory map, for instance via the remote
4164 protocol's "qXfer:memory-map:read" packet, setting this variable
4165 prevents GDB from accessing memory outside the memory map. This
4166 is useful for targets with memory mapped registers or which react
4167 badly to accesses of unmapped address space.
4169 set breakpoint auto-hw
4170 show breakpoint auto-hw
4171 If the target supplies a memory map, for instance via the remote
4172 protocol's "qXfer:memory-map:read" packet, setting this variable
4173 lets GDB use hardware breakpoints automatically for memory regions
4174 where it can not use software breakpoints. This covers both the
4175 "break" command and internal breakpoints used for other commands
4176 including "next" and "finish".
4179 catch exception unhandled
4180 Stop the program execution when Ada exceptions are raised.
4183 Stop the program execution when an Ada assertion failed.
4187 Set an alternate system root for target files. This is a more
4188 general version of "set solib-absolute-prefix", which is now
4189 an alias to "set sysroot".
4192 Provide extended SPU facility status information. This set of
4193 commands is available only when debugging the Cell/B.E. SPU
4196 * New native configurations
4198 OpenBSD/sh sh*-*openbsd*
4201 unset tdesc filename
4203 Use the specified local file as an XML target description, and do
4204 not query the target for its built-in description.
4208 OpenBSD/sh sh*-*-openbsd*
4209 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4210 Toshiba Media Processor mep-elf
4212 * New remote packets
4215 Ignore the specified signals; pass them directly to the debugged program
4216 without stopping other threads or reporting them to GDB.
4218 qXfer:features:read:
4219 Read an XML target description from the target, which describes its
4224 Read or write contents of an spufs file on the target system. These
4225 packets are available only on the Cell/B.E. SPU architecture.
4227 qXfer:libraries:read:
4228 Report the loaded shared libraries. Combined with new "T" packet
4229 response, this packet allows GDB to debug shared libraries on
4230 targets where the operating system manages the list of loaded
4231 libraries (e.g. Windows and SymbianOS).
4235 Support for these obsolete configurations has been removed.
4243 i[34567]86-*-lynxos*
4244 i[34567]86-*-netware*
4245 i[34567]86-*-sco3.2v5*
4246 i[34567]86-*-sco3.2v4*
4248 i[34567]86-*-sysv4.2*
4251 i[34567]86-*-unixware2*
4252 i[34567]86-*-unixware*
4261 * Other removed features
4268 Various m68k-only ROM monitors.
4275 Various Renesas ROM monitors and debugging interfaces for SH and
4280 Support for a Macraigor serial interface to on-chip debugging.
4281 GDB does not directly support the newer parallel or USB
4286 A debug information format. The predecessor to DWARF 2 and
4287 DWARF 3, which are still supported.
4289 Support for the HP aCC compiler on HP-UX/PA-RISC
4291 SOM-encapsulated symbolic debugging information, automatic
4292 invocation of pxdb, and the aCC custom C++ ABI. This does not
4293 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4294 with aCC can still be debugged on an assembly level.
4296 MIPS ".pdr" sections
4298 A MIPS-specific format used to describe stack frame layout
4299 in debugging information.
4303 GDB could work with an older version of Guile to debug
4304 the interpreter and Scheme programs running in it.
4306 set mips stack-arg-size
4307 set mips saved-gpreg-size
4309 Use "set mips abi" to control parameter passing for MIPS.
4311 *** Changes in GDB 6.6
4316 Cell Broadband Engine SPU spu-elf
4318 * GDB can now be configured as a cross-debugger targeting native Windows
4319 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4320 running on a Windows system over TCP/IP to debug Windows programs.
4322 * The GDB remote stub, gdbserver, has been updated to support Windows and
4323 Cygwin debugging. Both single-threaded and multi-threaded programs are
4326 * The "set trust-readonly-sections" command works again. This command was
4327 broken in GDB 6.3, 6.4, and 6.5.
4329 * The "load" command now supports writing to flash memory, if the remote
4330 stub provides the required support.
4332 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4333 longer requires symbolic debug information (e.g. DWARF-2).
4338 unset substitute-path
4339 show substitute-path
4340 Manage a list of substitution rules that GDB uses to rewrite the name
4341 of the directories where the sources are located. This can be useful
4342 for instance when the sources were moved to a different location
4343 between compilation and debugging.
4347 Print each CLI command as it is executed. Each command is prefixed with
4348 a number of `+' symbols representing the nesting depth.
4349 The source command now has a `-v' option to enable the same feature.
4353 The ARM Demon monitor support (RDP protocol, "target rdp").
4355 Kernel Object Display, an embedded debugging feature which only worked with
4356 an obsolete version of Cisco IOS.
4358 The 'set download-write-size' and 'show download-write-size' commands.
4360 * New remote packets
4363 Tell a stub about GDB client features, and request remote target features.
4364 The first feature implemented is PacketSize, which allows the target to
4365 specify the size of packets it can handle - to minimize the number of
4366 packets required and improve performance when connected to a remote
4370 Fetch an OS auxilliary vector from the remote stub. This packet is a
4371 more efficient replacement for qPart:auxv:read.
4373 qXfer:memory-map:read:
4374 Fetch a memory map from the remote stub, including information about
4375 RAM, ROM, and flash memory devices.
4380 Erase and program a flash memory device.
4382 * Removed remote packets
4385 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4386 used it, and only gdbserver implemented it.
4388 *** Changes in GDB 6.5
4392 Renesas M32C/M16C m32c-elf
4394 Morpho Technologies ms1 ms1-elf
4398 init-if-undefined Initialize a convenience variable, but
4399 only if it doesn't already have a value.
4401 The following commands are presently only implemented for native GNU/Linux:
4403 checkpoint Save a snapshot of the program state.
4405 restart <n> Return the program state to a
4406 previously saved state.
4408 info checkpoints List currently saved checkpoints.
4410 delete-checkpoint <n> Delete a previously saved checkpoint.
4412 set|show detach-on-fork Tell gdb whether to detach from a newly
4413 forked process, or to keep debugging it.
4415 info forks List forks of the user program that
4416 are available to be debugged.
4418 fork <n> Switch to debugging one of several
4419 forks of the user program that are
4420 available to be debugged.
4422 delete-fork <n> Delete a fork from the list of forks
4423 that are available to be debugged (and
4424 kill the forked process).
4426 detach-fork <n> Delete a fork from the list of forks
4427 that are available to be debugged (and
4428 allow the process to continue).
4432 Morpho Technologies ms2 ms1-elf
4434 * Improved Windows host support
4436 GDB now builds as a cross debugger hosted on i686-mingw32, including
4437 native console support, and remote communications using either
4438 network sockets or serial ports.
4440 * Improved Modula-2 language support
4442 GDB can now print most types in the Modula-2 syntax. This includes:
4443 basic types, set types, record types, enumerated types, range types,
4444 pointer types and ARRAY types. Procedure var parameters are correctly
4445 printed and hexadecimal addresses and character constants are also
4446 written in the Modula-2 syntax. Best results can be obtained by using
4447 GNU Modula-2 together with the -gdwarf-2 command line option.
4451 The ARM rdi-share module.
4453 The Netware NLM debug server.
4455 *** Changes in GDB 6.4
4457 * New native configurations
4459 OpenBSD/arm arm*-*-openbsd*
4460 OpenBSD/mips64 mips64-*-openbsd*
4464 Morpho Technologies ms1 ms1-elf
4466 * New command line options
4468 --batch-silent As for --batch, but totally silent.
4469 --return-child-result The debugger will exist with the same value
4470 the child (debugged) program exited with.
4471 --eval-command COMMAND, -ex COMMAND
4472 Execute a single GDB CLI command. This may be
4473 specified multiple times and in conjunction
4474 with the --command (-x) option.
4476 * Deprecated commands removed
4478 The following commands, that were deprecated in 2000, have been
4482 set|show arm disassembly-flavor set|show arm disassembler
4483 othernames set arm disassembler
4484 set|show remotedebug set|show debug remote
4485 set|show archdebug set|show debug arch
4486 set|show eventdebug set|show debug event
4489 * New BSD user-level threads support
4491 It is now possible to debug programs using the user-level threads
4492 library on OpenBSD and FreeBSD. Currently supported (target)
4495 FreeBSD/amd64 x86_64-*-freebsd*
4496 FreeBSD/i386 i386-*-freebsd*
4497 OpenBSD/i386 i386-*-openbsd*
4499 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4500 are not yet supported.
4502 * New support for Matsushita MN10300 w/sim added
4503 (Work in progress). mn10300-elf.
4505 * REMOVED configurations and files
4507 VxWorks and the XDR protocol *-*-vxworks
4508 Motorola MCORE mcore-*-*
4509 National Semiconductor NS32000 ns32k-*-*
4511 * New "set print array-indexes" command
4513 After turning this setting "on", GDB prints the index of each element
4514 when displaying arrays. The default is "off" to preserve the previous
4517 * VAX floating point support
4519 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4521 * User-defined command support
4523 In addition to using $arg0..$arg9 for argument passing, it is now possible
4524 to use $argc to determine now many arguments have been passed. See the
4525 section on user-defined commands in the user manual for more information.
4527 *** Changes in GDB 6.3:
4529 * New command line option
4531 GDB now accepts -l followed by a number to set the timeout for remote
4534 * GDB works with GCC -feliminate-dwarf2-dups
4536 GDB now supports a more compact representation of DWARF-2 debug
4537 information using DW_FORM_ref_addr references. These are produced
4538 by GCC with the option -feliminate-dwarf2-dups and also by some
4539 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4540 to use -feliminate-dwarf2-dups.
4542 * Internationalization
4544 When supported by the host system, GDB will be built with
4545 internationalization (libintl). The task of marking up the sources is
4546 continued, we're looking forward to our first translation.
4550 Initial support for debugging programs compiled with the GNAT
4551 implementation of the Ada programming language has been integrated
4552 into GDB. In this release, support is limited to expression evaluation.
4554 * New native configurations
4556 GNU/Linux/m32r m32r-*-linux-gnu
4560 GDB's remote protocol now includes support for the 'p' packet. This
4561 packet is used to fetch individual registers from a remote inferior.
4563 * END-OF-LIFE registers[] compatibility module
4565 GDB's internal register infrastructure has been completely rewritten.
4566 The new infrastructure making possible the implementation of key new
4567 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4570 GDB 6.3 will be the last release to include the the registers[]
4571 compatibility module that allowed out-of-date configurations to
4572 continue to work. This change directly impacts the following
4582 powerpc bdm protocol
4584 Unless there is activity to revive these configurations, they will be
4585 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4587 * OBSOLETE configurations and files
4589 Configurations that have been declared obsolete in this release have
4590 been commented out. Unless there is activity to revive these
4591 configurations, the next release of GDB will have their sources
4592 permanently REMOVED.
4601 *** Changes in GDB 6.2.1:
4603 * MIPS `break main; run' gave an heuristic-fence-post warning
4605 When attempting to run even a simple program, a warning about
4606 heuristic-fence-post being hit would be reported. This problem has
4609 * MIPS IRIX 'long double' crashed GDB
4611 When examining a long double variable, GDB would get a segmentation
4612 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4613 IRIX long double values).
4617 A bug in the VAX stack code was causing problems with the "next"
4618 command. This problem has been fixed.
4620 *** Changes in GDB 6.2:
4622 * Fix for ``many threads''
4624 On GNU/Linux systems that use the NPTL threads library, a program
4625 rapidly creating and deleting threads would confuse GDB leading to the
4628 ptrace: No such process.
4629 thread_db_get_info: cannot get thread info: generic error
4631 This problem has been fixed.
4633 * "-async" and "-noasync" options removed.
4635 Support for the broken "-noasync" option has been removed (it caused
4638 * New ``start'' command.
4640 This command runs the program until the begining of the main procedure.
4642 * New BSD Kernel Data Access Library (libkvm) interface
4644 Using ``target kvm'' it is now possible to debug kernel core dumps and
4645 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4646 platforms. Currently supported (native-only) configurations are:
4648 FreeBSD/amd64 x86_64-*-freebsd*
4649 FreeBSD/i386 i?86-*-freebsd*
4650 NetBSD/i386 i?86-*-netbsd*
4651 NetBSD/m68k m68*-*-netbsd*
4652 NetBSD/sparc sparc-*-netbsd*
4653 OpenBSD/amd64 x86_64-*-openbsd*
4654 OpenBSD/i386 i?86-*-openbsd*
4655 OpenBSD/m68k m68*-openbsd*
4656 OpenBSD/sparc sparc-*-openbsd*
4658 * Signal trampoline code overhauled
4660 Many generic problems with GDB's signal handling code have been fixed.
4661 These include: backtraces through non-contiguous stacks; recognition
4662 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4663 call; backtrace through a signal trampoline; step into and out of
4664 signal handlers; and single-stepping in the signal trampoline.
4666 Please note that kernel bugs are a limiting factor here. These
4667 features have been shown to work on an s390 GNU/Linux system that
4668 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4670 * Cygwin support for DWARF 2 added.
4672 * New native configurations
4674 GNU/Linux/hppa hppa*-*-linux*
4675 OpenBSD/hppa hppa*-*-openbsd*
4676 OpenBSD/m68k m68*-*-openbsd*
4677 OpenBSD/m88k m88*-*-openbsd*
4678 OpenBSD/powerpc powerpc-*-openbsd*
4679 NetBSD/vax vax-*-netbsd*
4680 OpenBSD/vax vax-*-openbsd*
4682 * END-OF-LIFE frame compatibility module
4684 GDB's internal frame infrastructure has been completely rewritten.
4685 The new infrastructure making it possible to support key new features
4686 including DWARF 2 Call Frame Information. To aid in the task of
4687 migrating old configurations to this new infrastructure, a
4688 compatibility module, that allowed old configurations to continue to
4689 work, was also included.
4691 GDB 6.2 will be the last release to include this frame compatibility
4692 module. This change directly impacts the following configurations:
4702 Unless there is activity to revive these configurations, they will be
4703 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4705 * REMOVED configurations and files
4707 Sun 3, running SunOS 3 m68*-*-sunos3*
4708 Sun 3, running SunOS 4 m68*-*-sunos4*
4709 Sun 2, running SunOS 3 m68000-*-sunos3*
4710 Sun 2, running SunOS 4 m68000-*-sunos4*
4711 Motorola 680x0 running LynxOS m68*-*-lynxos*
4712 AT&T 3b1/Unix pc m68*-att-*
4713 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4714 decstation mips-dec-* mips-little-*
4715 riscos mips-*-riscos* mips-*-sysv*
4716 sonymips mips-sony-*
4717 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4719 *** Changes in GDB 6.1.1:
4721 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4723 The TUI (Text-mode User Interface) is now built as part of a default
4724 GDB configuration. It is enabled by either selecting the TUI with the
4725 command line option "-i=tui" or by running the separate "gdbtui"
4726 program. For more information on the TUI, see the manual "Debugging
4729 * Pending breakpoint support (also included in GDB 6.1)
4731 Support has been added to allow you to specify breakpoints in shared
4732 libraries that have not yet been loaded. If a breakpoint location
4733 cannot be found, and the "breakpoint pending" option is set to auto,
4734 GDB queries you if you wish to make the breakpoint pending on a future
4735 shared-library load. If and when GDB resolves the breakpoint symbol,
4736 the pending breakpoint is removed as one or more regular breakpoints
4739 Pending breakpoints are very useful for GCJ Java debugging.
4741 * Fixed ISO-C build problems
4743 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4744 non ISO-C code that stopped them being built using a more strict ISO-C
4745 compiler (e.g., IBM's C compiler).
4747 * Fixed build problem on IRIX 5
4749 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4750 wasn't able to compile compile on an IRIX 5 system.
4752 * Added execute permission to gdb/gdbserver/configure
4754 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4755 permission. This bug would cause configure to fail on a number of
4756 systems (Solaris, IRIX). Ref: server/519.
4758 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4760 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4761 has been updated to use constant array sizes.
4763 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4765 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4766 its generated DWARF Call Frame Info. This encoding was causing GDB to
4767 panic, that panic has been fixed. Ref: gdb/1628.
4769 * Fixed a problem when examining parameters in shared library code.
4771 When examining parameters in optimized shared library code generated
4772 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4773 not available''. GDB now correctly displays the variable's value.
4775 *** Changes in GDB 6.1:
4777 * Removed --with-mmalloc
4779 Support for the mmalloc memory manager has been removed, as it
4780 conflicted with the internal gdb byte cache.
4782 * Changes in AMD64 configurations
4784 The AMD64 target now includes the %cs and %ss registers. As a result
4785 the AMD64 remote protocol has changed; this affects the floating-point
4786 and SSE registers. If you rely on those registers for your debugging,
4787 you should upgrade gdbserver on the remote side.
4789 * Revised SPARC target
4791 The SPARC target has been completely revised, incorporating the
4792 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4793 support for LynxOS and SunOS 4 has been dropped. Calling functions
4794 from within GDB on operating systems with a non-executable stack
4795 (Solaris, OpenBSD) now works.
4799 GDB has a new C++ demangler which does a better job on the mangled
4800 names generated by current versions of g++. It also runs faster, so
4801 with this and other changes gdb should now start faster on large C++
4804 * DWARF 2 Location Expressions
4806 GDB support for location expressions has been extended to support function
4807 arguments and frame bases. Older versions of GDB could crash when they
4810 * C++ nested types and namespaces
4812 GDB's support for nested types and namespaces in C++ has been
4813 improved, especially if you use the DWARF 2 debugging format. (This
4814 is the default for recent versions of GCC on most platforms.)
4815 Specifically, if you have a class "Inner" defined within a class or
4816 namespace "Outer", then GDB realizes that the class's name is
4817 "Outer::Inner", not simply "Inner". This should greatly reduce the
4818 frequency of complaints about not finding RTTI symbols. In addition,
4819 if you are stopped at inside of a function defined within a namespace,
4820 GDB modifies its name lookup accordingly.
4822 * New native configurations
4824 NetBSD/amd64 x86_64-*-netbsd*
4825 OpenBSD/amd64 x86_64-*-openbsd*
4826 OpenBSD/alpha alpha*-*-openbsd*
4827 OpenBSD/sparc sparc-*-openbsd*
4828 OpenBSD/sparc64 sparc64-*-openbsd*
4830 * New debugging protocols
4832 M32R with SDI protocol m32r-*-elf*
4834 * "set prompt-escape-char" command deleted.
4836 The command "set prompt-escape-char" has been deleted. This command,
4837 and its very obscure effet on GDB's prompt, was never documented,
4838 tested, nor mentioned in the NEWS file.
4840 * OBSOLETE configurations and files
4842 Configurations that have been declared obsolete in this release have
4843 been commented out. Unless there is activity to revive these
4844 configurations, the next release of GDB will have their sources
4845 permanently REMOVED.
4847 Sun 3, running SunOS 3 m68*-*-sunos3*
4848 Sun 3, running SunOS 4 m68*-*-sunos4*
4849 Sun 2, running SunOS 3 m68000-*-sunos3*
4850 Sun 2, running SunOS 4 m68000-*-sunos4*
4851 Motorola 680x0 running LynxOS m68*-*-lynxos*
4852 AT&T 3b1/Unix pc m68*-att-*
4853 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4854 decstation mips-dec-* mips-little-*
4855 riscos mips-*-riscos* mips-*-sysv*
4856 sonymips mips-sony-*
4857 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4859 * REMOVED configurations and files
4861 SGI Irix-4.x mips-sgi-irix4 or iris4
4862 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4863 Z8000 simulator z8k-zilog-none or z8ksim
4864 Matsushita MN10200 w/simulator mn10200-*-*
4865 H8/500 simulator h8500-hitachi-hms or h8500hms
4866 HP/PA running BSD hppa*-*-bsd*
4867 HP/PA running OSF/1 hppa*-*-osf*
4868 HP/PA Pro target hppa*-*-pro*
4869 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4870 386BSD i[3456]86-*-bsd*
4871 Sequent family i[3456]86-sequent-sysv4*
4872 i[3456]86-sequent-sysv*
4873 i[3456]86-sequent-bsd*
4874 SPARC running LynxOS sparc-*-lynxos*
4875 SPARC running SunOS 4 sparc-*-sunos4*
4876 Tsqware Sparclet sparclet-*-*
4877 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4879 *** Changes in GDB 6.0:
4883 Support for debugging the Objective-C programming language has been
4884 integrated into GDB.
4886 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4888 DWARF 2's Call Frame Information makes available compiler generated
4889 information that more exactly describes the program's run-time stack.
4890 By using this information, GDB is able to provide more robust stack
4893 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4894 have been updated to use a new backtrace mechanism which includes
4895 DWARF 2 CFI support.
4899 GDB's remote protocol has been extended to include support for hosted
4900 file I/O (where the remote target uses GDB's file system). See GDB's
4901 remote protocol documentation for details.
4903 * All targets using the new architecture framework.
4905 All of GDB's targets have been updated to use the new internal
4906 architecture framework. The way is now open for future GDB releases
4907 to include cross-architecture native debugging support (i386 on amd64,
4910 * GNU/Linux's Thread Local Storage (TLS)
4912 GDB now includes support for for the GNU/Linux implementation of
4913 per-thread variables.
4915 * GNU/Linux's Native POSIX Thread Library (NPTL)
4917 GDB's thread code has been updated to work with either the new
4918 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4920 * Separate debug info.
4922 GDB, in conjunction with BINUTILS, now supports a mechanism for
4923 automatically loading debug information from a separate file. Instead
4924 of shipping full debug and non-debug versions of system libraries,
4925 system integrators can now instead ship just the stripped libraries
4926 and optional debug files.
4928 * DWARF 2 Location Expressions
4930 DWARF 2 Location Expressions allow the compiler to more completely
4931 describe the location of variables (even in optimized code) to the
4934 GDB now includes preliminary support for location expressions (support
4935 for DW_OP_piece is still missing).
4939 A number of long standing bugs that caused GDB to die while starting a
4940 Java application have been fixed. GDB's Java support is now
4941 considered "useable".
4943 * GNU/Linux support for fork, vfork, and exec.
4945 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4946 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4949 * GDB supports logging output to a file
4951 There are two new commands, "set logging" and "show logging", which can be
4952 used to capture GDB's output to a file.
4954 * The meaning of "detach" has changed for gdbserver
4956 The "detach" command will now resume the application, as documented. To
4957 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4960 * d10v, m68hc11 `regs' command deprecated
4962 The `info registers' command has been updated so that it displays the
4963 registers using a format identical to the old `regs' command.
4967 A new command, "maint set profile on/off", has been added. This command can
4968 be used to enable or disable profiling while running GDB, to profile a
4969 session or a set of commands. In addition there is a new configure switch,
4970 "--enable-profiling", which will cause GDB to be compiled with profiling
4971 data, for more informative profiling results.
4973 * Default MI syntax changed to "mi2".
4975 The default MI (machine interface) syntax, enabled by the command line
4976 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4977 "mi1", can be enabled by specifying the option "-i=mi1".
4979 Support for the original "mi0" syntax (included in GDB 5.0) has been
4982 Fix for gdb/192: removed extraneous space when displaying frame level.
4983 Fix for gdb/672: update changelist is now output in mi list format.
4984 Fix for gdb/702: a -var-assign that updates the value now shows up
4985 in a subsequent -var-update.
4987 * New native configurations.
4989 FreeBSD/amd64 x86_64-*-freebsd*
4991 * Multi-arched targets.
4993 HP/PA HPUX11 hppa*-*-hpux*
4994 Renesas M32R/D w/simulator m32r-*-elf*
4996 * OBSOLETE configurations and files
4998 Configurations that have been declared obsolete in this release have
4999 been commented out. Unless there is activity to revive these
5000 configurations, the next release of GDB will have their sources
5001 permanently REMOVED.
5003 Z8000 simulator z8k-zilog-none or z8ksim
5004 Matsushita MN10200 w/simulator mn10200-*-*
5005 H8/500 simulator h8500-hitachi-hms or h8500hms
5006 HP/PA running BSD hppa*-*-bsd*
5007 HP/PA running OSF/1 hppa*-*-osf*
5008 HP/PA Pro target hppa*-*-pro*
5009 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5010 Sequent family i[3456]86-sequent-sysv4*
5011 i[3456]86-sequent-sysv*
5012 i[3456]86-sequent-bsd*
5013 Tsqware Sparclet sparclet-*-*
5014 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5016 * REMOVED configurations and files
5019 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5020 IBM AIX PS/2 i[3456]86-*-aix
5021 i386 running Mach 3.0 i[3456]86-*-mach3*
5022 i386 running Mach i[3456]86-*-mach*
5023 i386 running OSF/1 i[3456]86-*osf1mk*
5024 HP/Apollo 68k Family m68*-apollo*-sysv*,
5026 m68*-hp-bsd*, m68*-hp-hpux*
5027 Argonaut Risc Chip (ARC) arc-*-*
5028 Mitsubishi D30V d30v-*-*
5029 Fujitsu FR30 fr30-*-elf*
5030 OS/9000 i[34]86-*-os9k
5031 I960 with MON960 i960-*-coff
5033 * MIPS $fp behavior changed
5035 The convenience variable $fp, for the MIPS, now consistently returns
5036 the address of the current frame's base. Previously, depending on the
5037 context, $fp could refer to either $sp or the current frame's base
5038 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5039 The GNU Source-Level Debugger''.
5041 *** Changes in GDB 5.3:
5043 * GNU/Linux shared library multi-threaded performance improved.
5045 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5046 `/proc', in preference to `ptrace' for memory reads. This may result
5047 in an improvement in the start-up time of multi-threaded, shared
5048 library applications when run under GDB. One GDB user writes: ``loads
5049 shared libs like mad''.
5051 * ``gdbserver'' now supports multi-threaded applications on some targets
5053 Support for debugging multi-threaded applications which use
5054 the GNU/Linux LinuxThreads package has been added for
5055 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5056 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5058 * GDB now supports C/C++ preprocessor macros.
5060 GDB now expands preprocessor macro invocations in C/C++ expressions,
5061 and provides various commands for showing macro definitions and how
5064 The new command `macro expand EXPRESSION' expands any macro
5065 invocations in expression, and shows the result.
5067 The new command `show macro MACRO-NAME' shows the definition of the
5068 macro named MACRO-NAME, and where it was defined.
5070 Most compilers don't include information about macros in the debugging
5071 information by default. In GCC 3.1, for example, you need to compile
5072 your program with the options `-gdwarf-2 -g3'. If the macro
5073 information is present in the executable, GDB will read it.
5075 * Multi-arched targets.
5077 DEC Alpha (partial) alpha*-*-*
5078 DEC VAX (partial) vax-*-*
5080 National Semiconductor NS32000 (partial) ns32k-*-*
5081 Motorola 68000 (partial) m68k-*-*
5082 Motorola MCORE mcore-*-*
5086 Fujitsu FRV architecture added by Red Hat frv*-*-*
5089 * New native configurations
5091 Alpha NetBSD alpha*-*-netbsd*
5092 SH NetBSD sh*-*-netbsdelf*
5093 MIPS NetBSD mips*-*-netbsd*
5094 UltraSPARC NetBSD sparc64-*-netbsd*
5096 * OBSOLETE configurations and files
5098 Configurations that have been declared obsolete in this release have
5099 been commented out. Unless there is activity to revive these
5100 configurations, the next release of GDB will have their sources
5101 permanently REMOVED.
5103 Mitsubishi D30V d30v-*-*
5104 OS/9000 i[34]86-*-os9k
5105 IBM AIX PS/2 i[3456]86-*-aix
5106 Fujitsu FR30 fr30-*-elf*
5107 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5108 Argonaut Risc Chip (ARC) arc-*-*
5109 i386 running Mach 3.0 i[3456]86-*-mach3*
5110 i386 running Mach i[3456]86-*-mach*
5111 i386 running OSF/1 i[3456]86-*osf1mk*
5112 HP/Apollo 68k Family m68*-apollo*-sysv*,
5114 m68*-hp-bsd*, m68*-hp-hpux*
5115 I960 with MON960 i960-*-coff
5117 * OBSOLETE languages
5119 CHILL, a Pascal like language used by telecommunications companies.
5121 * REMOVED configurations and files
5123 AMD 29k family via UDI a29k-amd-udi, udi29k
5124 A29K VxWorks a29k-*-vxworks
5125 AMD 29000 embedded, using EBMON a29k-none-none
5126 AMD 29000 embedded with COFF a29k-none-coff
5127 AMD 29000 embedded with a.out a29k-none-aout
5129 testsuite/gdb.hp/gdb.threads-hp/ directory
5131 * New command "set max-user-call-depth <nnn>"
5133 This command allows the user to limit the call depth of user-defined
5134 commands. The default is 1024.
5136 * Changes in FreeBSD/i386 native debugging.
5138 Support for the "generate-core-file" has been added.
5140 * New commands "dump", "append", and "restore".
5142 These commands allow data to be copied from target memory
5143 to a bfd-format or binary file (dump and append), and back
5144 from a file into memory (restore).
5146 * Improved "next/step" support on multi-processor Alpha Tru64.
5148 The previous single-step mechanism could cause unpredictable problems,
5149 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5150 of a software single-step mechanism prevents this.
5152 *** Changes in GDB 5.2.1:
5160 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5161 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5162 Fix, by Joel Brobecker imported from mainline.
5164 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5165 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5166 Fix, by Fred Fish, imported from mainline.
5168 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5169 Surprisingly enough, it works now.
5170 By Michal Ludvig, imported from mainline.
5172 i386 hardware watchpoint support:
5173 avoid misses on second run for some targets.
5174 By Pierre Muller, imported from mainline.
5176 *** Changes in GDB 5.2:
5178 * New command "set trust-readonly-sections on[off]".
5180 This command is a hint that tells gdb that read-only sections
5181 really are read-only (ie. that their contents will not change).
5182 In this mode, gdb will go to the object file rather than the
5183 target to read memory from read-only sections (such as ".text").
5184 This can be a significant performance improvement on some
5185 (notably embedded) targets.
5187 * New command "generate-core-file" (or "gcore").
5189 This new gdb command allows the user to drop a core file of the child
5190 process state at any time. So far it's been implemented only for
5191 GNU/Linux and Solaris, but should be relatively easily ported to other
5192 hosts. Argument is core file name (defaults to core.<pid>).
5194 * New command line option
5196 GDB now accepts --pid or -p followed by a process id.
5198 * Change in command line behavior -- corefiles vs. process ids.
5200 There is a subtle behavior in the way in which GDB handles
5201 command line arguments. The first non-flag argument is always
5202 a program to debug, but the second non-flag argument may either
5203 be a corefile or a process id. Previously, GDB would attempt to
5204 open the second argument as a corefile, and if that failed, would
5205 issue a superfluous error message and then attempt to attach it as
5206 a process. Now, if the second argument begins with a non-digit,
5207 it will be treated as a corefile. If it begins with a digit,
5208 GDB will attempt to attach it as a process, and if no such process
5209 is found, will then attempt to open it as a corefile.
5211 * Changes in ARM configurations.
5213 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5214 configuration is fully multi-arch.
5216 * New native configurations
5218 ARM NetBSD arm*-*-netbsd*
5219 x86 OpenBSD i[3456]86-*-openbsd*
5220 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5221 Sparc64 running FreeBSD sparc64-*-freebsd*
5225 Sanyo XStormy16 xstormy16-elf
5227 * OBSOLETE configurations and files
5229 Configurations that have been declared obsolete in this release have
5230 been commented out. Unless there is activity to revive these
5231 configurations, the next release of GDB will have their sources
5232 permanently REMOVED.
5234 AMD 29k family via UDI a29k-amd-udi, udi29k
5235 A29K VxWorks a29k-*-vxworks
5236 AMD 29000 embedded, using EBMON a29k-none-none
5237 AMD 29000 embedded with COFF a29k-none-coff
5238 AMD 29000 embedded with a.out a29k-none-aout
5240 testsuite/gdb.hp/gdb.threads-hp/ directory
5242 * REMOVED configurations and files
5244 TI TMS320C80 tic80-*-*
5246 PowerPC Solaris powerpcle-*-solaris*
5247 PowerPC Windows NT powerpcle-*-cygwin32
5248 PowerPC Netware powerpc-*-netware*
5249 Harris/CXUX m88k m88*-harris-cxux*
5250 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5251 ns32k-utek-sysv* ns32k-utek-*
5252 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5253 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5254 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5255 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5256 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5258 * Changes to command line processing
5260 The new `--args' feature can be used to specify command-line arguments
5261 for the inferior from gdb's command line.
5263 * Changes to key bindings
5265 There is a new `operate-and-get-next' function bound to `C-o'.
5267 *** Changes in GDB 5.1.1
5269 Fix compile problem on DJGPP.
5271 Fix a problem with floating-point registers on the i386 being
5274 Fix to stop GDB crashing on .debug_str debug info.
5276 Numerous documentation fixes.
5278 Numerous testsuite fixes.
5280 *** Changes in GDB 5.1:
5282 * New native configurations
5284 Alpha FreeBSD alpha*-*-freebsd*
5285 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5286 MIPS GNU/Linux mips*-*-linux*
5287 MIPS SGI Irix 6.x mips*-sgi-irix6*
5288 ia64 AIX ia64-*-aix*
5289 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5293 Motorola 68HC11 and 68HC12 m68hc11-elf
5295 UltraSparc running GNU/Linux sparc64-*-linux*
5297 * OBSOLETE configurations and files
5299 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5300 Harris/CXUX m88k m88*-harris-cxux*
5301 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5302 ns32k-utek-sysv* ns32k-utek-*
5303 TI TMS320C80 tic80-*-*
5305 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5306 PowerPC Solaris powerpcle-*-solaris*
5307 PowerPC Windows NT powerpcle-*-cygwin32
5308 PowerPC Netware powerpc-*-netware*
5309 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5310 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5311 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5312 Apple Macintosh (MPW) host N/A
5314 stuff.c (Program to stuff files into a specially prepared space in kdb)
5315 kdb-start.c (Main loop for the standalone kernel debugger)
5317 Configurations that have been declared obsolete in this release have
5318 been commented out. Unless there is activity to revive these
5319 configurations, the next release of GDB will have their sources
5320 permanently REMOVED.
5322 * REMOVED configurations and files
5324 Altos 3068 m68*-altos-*
5325 Convex c1-*-*, c2-*-*
5327 ARM RISCix arm-*-* (as host)
5331 * GDB has been converted to ISO C.
5333 GDB's source code has been converted to ISO C. In particular, the
5334 sources are fully protoized, and rely on standard headers being
5339 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5341 * The MI enabled by default.
5343 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5344 revised and enabled by default. Packages which use GDB as a debugging
5345 engine behind a UI or another front end are encouraged to switch to
5346 using the GDB/MI interface, instead of the old annotations interface
5347 which is now deprecated.
5349 * Support for debugging Pascal programs.
5351 GDB now includes support for debugging Pascal programs. The following
5352 main features are supported:
5354 - Pascal-specific data types such as sets;
5356 - automatic recognition of Pascal sources based on file-name
5359 - Pascal-style display of data types, variables, and functions;
5361 - a Pascal expression parser.
5363 However, some important features are not yet supported.
5365 - Pascal string operations are not supported at all;
5367 - there are some problems with boolean types;
5369 - Pascal type hexadecimal constants are not supported
5370 because they conflict with the internal variables format;
5372 - support for Pascal objects and classes is not full yet;
5374 - unlike Pascal, GDB is case-sensitive for symbol names.
5376 * Changes in completion.
5378 Commands such as `shell', `run' and `set args', which pass arguments
5379 to inferior programs, now complete on file names, similar to what
5380 users expect at the shell prompt.
5382 Commands which accept locations, such as `disassemble', `print',
5383 `breakpoint', `until', etc. now complete on filenames as well as
5384 program symbols. Thus, if you type "break foob TAB", and the source
5385 files linked into the programs include `foobar.c', that file name will
5386 be one of the candidates for completion. However, file names are not
5387 considered for completion after you typed a colon that delimits a file
5388 name from a name of a function in that file, as in "break foo.c:bar".
5390 `set demangle-style' completes on available demangling styles.
5392 * New platform-independent commands:
5394 It is now possible to define a post-hook for a command as well as a
5395 hook that runs before the command. For more details, see the
5396 documentation of `hookpost' in the GDB manual.
5398 * Changes in GNU/Linux native debugging.
5400 Support for debugging multi-threaded programs has been completely
5401 revised for all platforms except m68k and sparc. You can now debug as
5402 many threads as your system allows you to have.
5404 Attach/detach is supported for multi-threaded programs.
5406 Support for SSE registers was added for x86. This doesn't work for
5407 multi-threaded programs though.
5409 * Changes in MIPS configurations.
5411 Multi-arch support is enabled for all MIPS configurations.
5413 GDB can now be built as native debugger on SGI Irix 6.x systems for
5414 debugging n32 executables. (Debugging 64-bit executables is not yet
5417 * Unified support for hardware watchpoints in all x86 configurations.
5419 Most (if not all) native x86 configurations support hardware-assisted
5420 breakpoints and watchpoints in a unified manner. This support
5421 implements debug register sharing between watchpoints, which allows to
5422 put a virtually infinite number of watchpoints on the same address,
5423 and also supports watching regions up to 16 bytes with several debug
5426 The new maintenance command `maintenance show-debug-regs' toggles
5427 debugging print-outs in functions that insert, remove, and test
5428 watchpoints and hardware breakpoints.
5430 * Changes in the DJGPP native configuration.
5432 New command ``info dos sysinfo'' displays assorted information about
5433 the CPU, OS, memory, and DPMI server.
5435 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5436 display information about segment descriptors stored in GDT, LDT, and
5439 New commands ``info dos pde'' and ``info dos pte'' display entries
5440 from Page Directory and Page Tables (for now works with CWSDPMI only).
5441 New command ``info dos address-pte'' displays the Page Table entry for
5442 a given linear address.
5444 GDB can now pass command lines longer than 126 characters to the
5445 program being debugged (requires an update to the libdbg.a library
5446 which is part of the DJGPP development kit).
5448 DWARF2 debug info is now supported.
5450 It is now possible to `step' and `next' through calls to `longjmp'.
5452 * Changes in documentation.
5454 All GDB documentation was converted to GFDL, the GNU Free
5455 Documentation License.
5457 Tracepoints-related commands are now fully documented in the GDB
5460 TUI, the Text-mode User Interface, is now documented in the manual.
5462 Tracepoints-related commands are now fully documented in the GDB
5465 The "GDB Internals" manual now has an index. It also includes
5466 documentation of `ui_out' functions, GDB coding standards, x86
5467 hardware watchpoints, and memory region attributes.
5469 * GDB's version number moved to ``version.in''
5471 The Makefile variable VERSION has been replaced by the file
5472 ``version.in''. People creating GDB distributions should update the
5473 contents of this file.
5477 GUD support is now a standard part of the EMACS distribution.
5479 *** Changes in GDB 5.0:
5481 * Improved support for debugging FP programs on x86 targets
5483 Unified and much-improved support for debugging floating-point
5484 programs on all x86 targets. In particular, ``info float'' now
5485 displays the FP registers in the same format on all x86 targets, with
5486 greater level of detail.
5488 * Improvements and bugfixes in hardware-assisted watchpoints
5490 It is now possible to watch array elements, struct members, and
5491 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5492 on x86 targets no longer erroneously trigger when the address is
5495 * Improvements in the native DJGPP version of GDB
5497 The distribution now includes all the scripts and auxiliary files
5498 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5499 machines ``out of the box''.
5501 The DJGPP version can now debug programs that use signals. It is
5502 possible to catch signals that happened in the debuggee, deliver
5503 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5504 would kill the program being debugged.) Programs that hook hardware
5505 interrupts (keyboard, timer, etc.) can also be debugged.
5507 It is now possible to debug DJGPP programs that redirect their
5508 standard handles or switch them to raw (as opposed to cooked) mode, or
5509 even close them. The command ``run < foo > bar'' works as expected,
5510 and ``info terminal'' reports useful information about the debuggee's
5511 terminal, including raw/cooked mode, redirection, etc.
5513 The DJGPP version now uses termios functions for console I/O, which
5514 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5517 DOS-style file names with drive letters are now fully supported by
5520 It is now possible to debug DJGPP programs that switch their working
5521 directory. It is also possible to rerun the debuggee any number of
5522 times without restarting GDB; thus, you can use the same setup,
5523 breakpoints, etc. for many debugging sessions.
5525 * New native configurations
5527 ARM GNU/Linux arm*-*-linux*
5528 PowerPC GNU/Linux powerpc-*-linux*
5532 Motorola MCore mcore-*-*
5533 x86 VxWorks i[3456]86-*-vxworks*
5534 PowerPC VxWorks powerpc-*-vxworks*
5535 TI TMS320C80 tic80-*-*
5537 * OBSOLETE configurations
5539 Altos 3068 m68*-altos-*
5540 Convex c1-*-*, c2-*-*
5542 ARM RISCix arm-*-* (as host)
5545 Configurations that have been declared obsolete will be commented out,
5546 but the code will be left in place. If there is no activity to revive
5547 these configurations before the next release of GDB, the sources will
5548 be permanently REMOVED.
5550 * Gould support removed
5552 Support for the Gould PowerNode and NP1 has been removed.
5554 * New features for SVR4
5556 On SVR4 native platforms (such as Solaris), if you attach to a process
5557 without first loading a symbol file, GDB will now attempt to locate and
5558 load symbols from the running process's executable file.
5560 * Many C++ enhancements
5562 C++ support has been greatly improved. Overload resolution now works properly
5563 in almost all cases. RTTI support is on the way.
5565 * Remote targets can connect to a sub-program
5567 A popen(3) style serial-device has been added. This device starts a
5568 sub-process (such as a stand-alone simulator) and then communicates
5569 with that. The sub-program to run is specified using the syntax
5570 ``|<program> <args>'' vis:
5572 (gdb) set remotedebug 1
5573 (gdb) target extended-remote |mn10300-elf-sim program-args
5575 * MIPS 64 remote protocol
5577 A long standing bug in the mips64 remote protocol where by GDB
5578 expected certain 32 bit registers (ex SR) to be transfered as 32
5579 instead of 64 bits has been fixed.
5581 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5582 added to provide backward compatibility with older versions of GDB.
5584 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5586 The command ``set remotebinarydownload'' command has been replaced by
5587 ``set remote X-packet''. Other commands in ``set remote'' family
5588 include ``set remote P-packet''.
5590 * Breakpoint commands accept ranges.
5592 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5593 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5594 ``tracepoint passcount'' also accepts a range of tracepoints.
5596 * ``apropos'' command added.
5598 The ``apropos'' command searches through command names and
5599 documentation strings, printing out matches, making it much easier to
5600 try to find a command that does what you are looking for.
5604 A new machine oriented interface (MI) has been added to GDB. This
5605 interface is designed for debug environments running GDB as a separate
5606 process. This is part of the long term libGDB project. See the
5607 "GDB/MI" chapter of the GDB manual for further information. It can be
5608 enabled by configuring with:
5610 .../configure --enable-gdbmi
5612 *** Changes in GDB-4.18:
5614 * New native configurations
5616 HP-UX 10.20 hppa*-*-hpux10.20
5617 HP-UX 11.x hppa*-*-hpux11.0*
5618 M68K GNU/Linux m68*-*-linux*
5622 Fujitsu FR30 fr30-*-elf*
5623 Intel StrongARM strongarm-*-*
5624 Mitsubishi D30V d30v-*-*
5626 * OBSOLETE configurations
5628 Gould PowerNode, NP1 np1-*-*, pn-*-*
5630 Configurations that have been declared obsolete will be commented out,
5631 but the code will be left in place. If there is no activity to revive
5632 these configurations before the next release of GDB, the sources will
5633 be permanently REMOVED.
5637 As a compatibility experiment, GDB's source files buildsym.h and
5638 buildsym.c have been converted to pure standard C, no longer
5639 containing any K&R compatibility code. We believe that all systems in
5640 use today either come with a standard C compiler, or have a GCC port
5641 available. If this is not true, please report the affected
5642 configuration to bug-gdb@gnu.org immediately. See the README file for
5643 information about getting a standard C compiler if you don't have one
5648 GDB now uses readline 2.2.
5650 * set extension-language
5652 You can now control the mapping between filename extensions and source
5653 languages by using the `set extension-language' command. For instance,
5654 you can ask GDB to treat .c files as C++ by saying
5655 set extension-language .c c++
5656 The command `info extensions' lists all of the recognized extensions
5657 and their associated languages.
5659 * Setting processor type for PowerPC and RS/6000
5661 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5662 you can use the `set processor' command to specify what variant of the
5663 PowerPC family you are debugging. The command
5667 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5668 following PowerPC and RS6000 variants:
5670 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5671 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5673 403GC IBM PowerPC 403GC
5674 505 Motorola PowerPC 505
5675 860 Motorola PowerPC 860 or 850
5676 601 Motorola PowerPC 601
5677 602 Motorola PowerPC 602
5678 603 Motorola/IBM PowerPC 603 or 603e
5679 604 Motorola PowerPC 604 or 604e
5680 750 Motorola/IBM PowerPC 750 or 750
5682 At the moment, this command just tells GDB what to name the
5683 special-purpose processor registers. Since almost all the affected
5684 registers are inaccessible to user-level programs, this command is
5685 only useful for remote debugging in its present form.
5689 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5690 more extensive support for HP-UX. Added features include shared
5691 library support, kernel threads and hardware watchpoints for 11.00,
5692 support for HP's ANSI C and C++ compilers, and a compatibility mode
5693 for xdb and dbx commands.
5697 HP's donation includes the new concept of catchpoints, which is a
5698 generalization of the old catch command. On HP-UX, it is now possible
5699 to catch exec, fork, and vfork, as well as library loading.
5701 This means that the existing catch command has changed; its first
5702 argument now specifies the type of catch to be set up. See the
5703 output of "help catch" for a list of catchpoint types.
5705 * Debugging across forks
5707 On HP-UX, you can choose which process to debug when a fork() happens
5712 HP has donated a curses-based terminal user interface (TUI). To get
5713 it, build with --enable-tui. Although this can be enabled for any
5714 configuration, at present it only works for native HP debugging.
5716 * GDB remote protocol additions
5718 A new protocol packet 'X' that writes binary data is now available.
5719 Default behavior is to try 'X', then drop back to 'M' if the stub
5720 fails to respond. The settable variable `remotebinarydownload'
5721 allows explicit control over the use of 'X'.
5723 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5724 full 64-bit address. The command
5726 set remoteaddresssize 32
5728 can be used to revert to the old behaviour. For existing remote stubs
5729 the change should not be noticed, as the additional address information
5732 In order to assist in debugging stubs, you may use the maintenance
5733 command `packet' to send any text string to the stub. For instance,
5735 maint packet heythere
5737 sends the packet "$heythere#<checksum>". Note that it is very easy to
5738 disrupt a debugging session by sending the wrong packet at the wrong
5741 The compare-sections command allows you to compare section data on the
5742 target to what is in the executable file without uploading or
5743 downloading, by comparing CRC checksums.
5745 * Tracing can collect general expressions
5747 You may now collect general expressions at tracepoints. This requires
5748 further additions to the target-side stub; see tracepoint.c and
5749 doc/agentexpr.texi for further details.
5751 * mask-address variable for Mips
5753 For Mips targets, you may control the zeroing of the upper 32 bits of
5754 a 64-bit address by entering `set mask-address on'. This is mainly
5755 of interest to users of embedded R4xxx and R5xxx processors.
5757 * Higher serial baud rates
5759 GDB's serial code now allows you to specify baud rates 57600, 115200,
5760 230400, and 460800 baud. (Note that your host system may not be able
5761 to achieve all of these rates.)
5765 The i960 configuration now includes an initial implementation of a
5766 builtin simulator, contributed by Jim Wilson.
5769 *** Changes in GDB-4.17:
5771 * New native configurations
5773 Alpha GNU/Linux alpha*-*-linux*
5774 Unixware 2.x i[3456]86-unixware2*
5775 Irix 6.x mips*-sgi-irix6*
5776 PowerPC GNU/Linux powerpc-*-linux*
5777 PowerPC Solaris powerpcle-*-solaris*
5778 Sparc GNU/Linux sparc-*-linux*
5779 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5783 Argonaut Risc Chip (ARC) arc-*-*
5784 Hitachi H8/300S h8300*-*-*
5785 Matsushita MN10200 w/simulator mn10200-*-*
5786 Matsushita MN10300 w/simulator mn10300-*-*
5787 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5788 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5789 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5790 Mitsubishi D10V w/simulator d10v-*-*
5791 Mitsubishi M32R/D w/simulator m32r-*-elf*
5792 Tsqware Sparclet sparclet-*-*
5793 NEC V850 w/simulator v850-*-*
5795 * New debugging protocols
5797 ARM with RDI protocol arm*-*-*
5798 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5799 DDB and LSI variants of PMON protocol mips*-*-*
5800 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5801 PowerPC with SDS protocol powerpc{,le}-*-eabi
5802 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5806 All configurations can now understand and use the DWARF 2 debugging
5807 format. The choice is automatic, if the symbol file contains DWARF 2
5812 GDB now includes basic Java language support. This support is
5813 only useful with Java compilers that produce native machine code.
5815 * solib-absolute-prefix and solib-search-path
5817 For SunOS and SVR4 shared libraries, you may now set the prefix for
5818 loading absolute shared library symbol files, and the search path for
5819 locating non-absolute shared library symbol files.
5821 * Live range splitting
5823 GDB can now effectively debug code for which GCC has performed live
5824 range splitting as part of its optimization. See gdb/doc/LRS for
5825 more details on the expected format of the stabs information.
5829 GDB's support for the GNU Hurd, including thread debugging, has been
5830 updated to work with current versions of the Hurd.
5834 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5835 instruction set. ARM GDB automatically detects when Thumb
5836 instructions are in use, and adjusts disassembly and backtracing
5841 GDB's MIPS target configurations now handle the MIP16 16-bit
5846 GDB now includes support for overlays; if an executable has been
5847 linked such that multiple sections are based at the same address, GDB
5848 will decide which section to use for symbolic info. You can choose to
5849 control the decision manually, using overlay commands, or implement
5850 additional target-side support and use "overlay load-target" to bring
5851 in the overlay mapping. Do "help overlay" for more detail.
5855 The command "info symbol <address>" displays information about
5856 the symbol at the specified address.
5860 The standard remote protocol now includes an extension that allows
5861 asynchronous collection and display of trace data. This requires
5862 extensive support in the target-side debugging stub. Tracing mode
5863 includes a new interaction mode in GDB and new commands: see the
5864 file tracepoint.c for more details.
5868 Configurations for embedded MIPS now include a simulator contributed
5869 by Cygnus Solutions. The simulator supports the instruction sets
5870 of most MIPS variants.
5874 Sparc configurations may now include the ERC32 simulator contributed
5875 by the European Space Agency. The simulator is not built into
5876 Sparc targets by default; configure with --enable-sim to include it.
5880 For target configurations that may include multiple variants of a
5881 basic architecture (such as MIPS and SH), you may now set the
5882 architecture explicitly. "set arch" sets, "info arch" lists
5883 the possible architectures.
5885 *** Changes in GDB-4.16:
5887 * New native configurations
5889 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5890 M68K NetBSD m68k-*-netbsd*
5891 PowerPC AIX 4.x powerpc-*-aix*
5892 PowerPC MacOS powerpc-*-macos*
5893 PowerPC Windows NT powerpcle-*-cygwin32
5894 RS/6000 AIX 4.x rs6000-*-aix4*
5898 ARM with RDP protocol arm-*-*
5899 I960 with MON960 i960-*-coff
5900 MIPS VxWorks mips*-*-vxworks*
5901 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5902 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5904 Matra Sparclet sparclet-*-*
5908 The powerpc-eabi configuration now includes the PSIM simulator,
5909 contributed by Andrew Cagney, with assistance from Mike Meissner.
5910 PSIM is a very elaborate model of the PowerPC, including not only
5911 basic instruction set execution, but also details of execution unit
5912 performance and I/O hardware. See sim/ppc/README for more details.
5916 GDB now works with Solaris 2.5.
5918 * Windows 95/NT native
5920 GDB will now work as a native debugger on Windows 95 and Windows NT.
5921 To build it from source, you must use the "gnu-win32" environment,
5922 which uses a DLL to emulate enough of Unix to run the GNU tools.
5923 Further information, binaries, and sources are available at
5924 ftp.cygnus.com, under pub/gnu-win32.
5926 * dont-repeat command
5928 If a user-defined command includes the command `dont-repeat', then the
5929 command will not be repeated if the user just types return. This is
5930 useful if the command is time-consuming to run, so that accidental
5931 extra keystrokes don't run the same command many times.
5933 * Send break instead of ^C
5935 The standard remote protocol now includes an option to send a break
5936 rather than a ^C to the target in order to interrupt it. By default,
5937 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5939 * Remote protocol timeout
5941 The standard remote protocol includes a new variable `remotetimeout'
5942 that allows you to set the number of seconds before GDB gives up trying
5943 to read from the target. The default value is 2.
5945 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5947 By default GDB will automatically keep track of objects as they are
5948 loaded and unloaded by the dynamic linker. By using the command `set
5949 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5950 when shared library events occur, thus allowing you to set breakpoints
5951 in shared libraries which are explicitly loaded by the inferior.
5953 Note this feature does not work on hpux8. On hpux9 you must link
5954 /usr/lib/end.o into your program. This feature should work
5955 automatically on hpux10.
5957 * Irix 5.x hardware watchpoint support
5959 Irix 5 configurations now support the use of hardware watchpoints.
5961 * Mips protocol "SYN garbage limit"
5963 When debugging a Mips target using the `target mips' protocol, you
5964 may set the number of characters that GDB will ignore by setting
5965 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5966 every character. The default value is 1050.
5968 * Recording and replaying remote debug sessions
5970 If you set `remotelogfile' to the name of a file, gdb will write to it
5971 a recording of a remote debug session. This recording may then be
5972 replayed back to gdb using "gdbreplay". See gdbserver/README for
5973 details. This is useful when you have a problem with GDB while doing
5974 remote debugging; you can make a recording of the session and send it
5975 to someone else, who can then recreate the problem.
5977 * Speedups for remote debugging
5979 GDB includes speedups for downloading and stepping MIPS systems using
5980 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5981 and more efficient S-record downloading.
5983 * Memory use reductions and statistics collection
5985 GDB now uses less memory and reports statistics about memory usage.
5986 Try the `maint print statistics' command, for example.
5988 *** Changes in GDB-4.15:
5990 * Psymtabs for XCOFF
5992 The symbol reader for AIX GDB now uses partial symbol tables. This
5993 can greatly improve startup time, especially for large executables.
5995 * Remote targets use caching
5997 Remote targets now use a data cache to speed up communication with the
5998 remote side. The data cache could lead to incorrect results because
5999 it doesn't know about volatile variables, thus making it impossible to
6000 debug targets which use memory mapped I/O devices. `set remotecache
6001 off' turns the the data cache off.
6003 * Remote targets may have threads
6005 The standard remote protocol now includes support for multiple threads
6006 in the target system, using new protocol commands 'H' and 'T'. See
6007 gdb/remote.c for details.
6011 If GDB is configured with `--enable-netrom', then it will include
6012 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6013 acts as though it is a bank of ROM on the target board, but you can
6014 write into it over the network. GDB's support consists only of
6015 support for fast loading into the emulated ROM; to debug, you must use
6016 another protocol, such as standard remote protocol. The usual
6017 sequence is something like
6019 target nrom <netrom-hostname>
6021 target remote <netrom-hostname>:1235
6025 GDB now includes support for the Apple Macintosh, as a host only. It
6026 may be run as either an MPW tool or as a standalone application, and
6027 it can debug through the serial port. All the usual GDB commands are
6028 available, but to the target command, you must supply "serial" as the
6029 device type instead of "/dev/ttyXX". See mpw-README in the main
6030 directory for more information on how to build. The MPW configuration
6031 scripts */mpw-config.in support only a few targets, and only the
6032 mips-idt-ecoff target has been tested.
6036 GDB configuration now uses autoconf. This is not user-visible,
6037 but does simplify configuration and building.
6041 GDB now supports hpux10.
6043 *** Changes in GDB-4.14:
6045 * New native configurations
6047 x86 FreeBSD i[345]86-*-freebsd
6048 x86 NetBSD i[345]86-*-netbsd
6049 NS32k NetBSD ns32k-*-netbsd
6050 Sparc NetBSD sparc-*-netbsd
6054 A29K VxWorks a29k-*-vxworks
6055 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6056 CPU32 EST-300 emulator m68*-*-est*
6057 PowerPC ELF powerpc-*-elf
6060 * Alpha OSF/1 support for procfs
6062 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6063 possible to attach to running processes. As the mounting of the /proc
6064 filesystem is optional on the Alpha, GDB automatically determines
6065 the availability of /proc during startup. This can lead to problems
6066 if /proc is unmounted after GDB has been started.
6068 * Arguments to user-defined commands
6070 User commands may accept up to 10 arguments separated by whitespace.
6071 Arguments are accessed within the user command via $arg0..$arg9. A
6074 print $arg0 + $arg1 + $arg2
6076 To execute the command use:
6079 Defines the command "adder" which prints the sum of its three arguments.
6080 Note the arguments are text substitutions, so they may reference variables,
6081 use complex expressions, or even perform inferior function calls.
6083 * New `if' and `while' commands
6085 This makes it possible to write more sophisticated user-defined
6086 commands. Both commands take a single argument, which is the
6087 expression to evaluate, and must be followed by the commands to
6088 execute, one per line, if the expression is nonzero, the list being
6089 terminated by the word `end'. The `if' command list may include an
6090 `else' word, which causes the following commands to be executed only
6091 if the expression is zero.
6093 * Fortran source language mode
6095 GDB now includes partial support for Fortran 77. It will recognize
6096 Fortran programs and can evaluate a subset of Fortran expressions, but
6097 variables and functions may not be handled correctly. GDB will work
6098 with G77, but does not yet know much about symbols emitted by other
6101 * Better HPUX support
6103 Most debugging facilities now work on dynamic executables for HPPAs
6104 running hpux9 or later. You can attach to running dynamically linked
6105 processes, but by default the dynamic libraries will be read-only, so
6106 for instance you won't be able to put breakpoints in them. To change
6107 that behavior do the following before running the program:
6113 This will cause the libraries to be mapped private and read-write.
6114 To revert to the normal behavior, do this:
6120 You cannot set breakpoints or examine data in the library until after
6121 the library is loaded if the function/data symbols do not have
6124 GDB can now also read debug symbols produced by the HP C compiler on
6125 HPPAs (sorry, no C++, Fortran or 68k support).
6127 * Target byte order now dynamically selectable
6129 You can choose which byte order to use with a target system, via the
6130 commands "set endian big" and "set endian little", and you can see the
6131 current setting by using "show endian". You can also give the command
6132 "set endian auto", in which case GDB will use the byte order
6133 associated with the executable. Currently, only embedded MIPS
6134 configurations support dynamic selection of target byte order.
6136 * New DOS host serial code
6138 This version uses DPMI interrupts to handle buffered I/O, so you
6139 no longer need to run asynctsr when debugging boards connected to
6142 *** Changes in GDB-4.13:
6144 * New "complete" command
6146 This lists all the possible completions for the rest of the line, if it
6147 were to be given as a command itself. This is intended for use by emacs.
6149 * Trailing space optional in prompt
6151 "set prompt" no longer adds a space for you after the prompt you set. This
6152 allows you to set a prompt which ends in a space or one that does not.
6154 * Breakpoint hit counts
6156 "info break" now displays a count of the number of times the breakpoint
6157 has been hit. This is especially useful in conjunction with "ignore"; you
6158 can ignore a large number of breakpoint hits, look at the breakpoint info
6159 to see how many times the breakpoint was hit, then run again, ignoring one
6160 less than that number, and this will get you quickly to the last hit of
6163 * Ability to stop printing at NULL character
6165 "set print null-stop" will cause GDB to stop printing the characters of
6166 an array when the first NULL is encountered. This is useful when large
6167 arrays actually contain only short strings.
6169 * Shared library breakpoints
6171 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6172 breakpoints in shared libraries before the executable is run.
6174 * Hardware watchpoints
6176 There is a new hardware breakpoint for the watch command for sparclite
6177 targets. See gdb/sparclite/hw_breakpoint.note.
6179 Hardware watchpoints are also now supported under GNU/Linux.
6183 Annotations have been added. These are for use with graphical interfaces,
6184 and are still experimental. Currently only gdba.el uses these.
6186 * Improved Irix 5 support
6188 GDB now works properly with Irix 5.2.
6190 * Improved HPPA support
6192 GDB now works properly with the latest GCC and GAS.
6194 * New native configurations
6196 Sequent PTX4 i[34]86-sequent-ptx4
6197 HPPA running OSF/1 hppa*-*-osf*
6198 Atari TT running SVR4 m68*-*-sysv4*
6199 RS/6000 LynxOS rs6000-*-lynxos*
6203 OS/9000 i[34]86-*-os9k
6204 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6207 * Hitachi SH7000 and E7000-PC ICE support
6209 There is now support for communicating with the Hitachi E7000-PC ICE.
6210 This is available automatically when GDB is configured for the SH.
6214 As usual, a variety of small fixes and improvements, both generic
6215 and configuration-specific. See the ChangeLog for more detail.
6217 *** Changes in GDB-4.12:
6219 * Irix 5 is now supported
6223 GDB-4.12 on the HPPA has a number of changes which make it unable
6224 to debug the output from the currently released versions of GCC and
6225 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6226 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6227 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6230 *** Changes in GDB-4.11:
6232 * User visible changes:
6236 The "set remotedebug" option is now consistent between the mips remote
6237 target, remote targets using the gdb-specific protocol, UDI (AMD's
6238 debug protocol for the 29k) and the 88k bug monitor. It is now an
6239 integer specifying a debug level (normally 0 or 1, but 2 means more
6240 debugging info for the mips target).
6242 * DEC Alpha native support
6244 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6245 debug info, but GDB works fairly well with the DEC compiler and should
6246 work with a future GCC release. See the README file for a few
6247 Alpha-specific notes.
6249 * Preliminary thread implementation
6251 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6253 * LynxOS native and target support for 386
6255 This release has been hosted on LynxOS 2.2, and also can be configured
6256 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6259 * Improvements in C++ mangling/demangling.
6261 This release has much better g++ debugging, specifically in name
6262 mangling/demangling, virtual function calls, print virtual table,
6263 call methods, ...etc.
6265 *** Changes in GDB-4.10:
6267 * User visible changes:
6269 Remote debugging using the GDB-specific (`target remote') protocol now
6270 supports the `load' command. This is only useful if you have some
6271 other way of getting the stub to the target system, and you can put it
6272 somewhere in memory where it won't get clobbered by the download.
6274 Filename completion now works.
6276 When run under emacs mode, the "info line" command now causes the
6277 arrow to point to the line specified. Also, "info line" prints
6278 addresses in symbolic form (as well as hex).
6280 All vxworks based targets now support a user settable option, called
6281 vxworks-timeout. This option represents the number of seconds gdb
6282 should wait for responses to rpc's. You might want to use this if
6283 your vxworks target is, perhaps, a slow software simulator or happens
6284 to be on the far side of a thin network line.
6288 This release contains support for using a DEC alpha as a GDB host for
6289 cross debugging. Native alpha debugging is not supported yet.
6292 *** Changes in GDB-4.9:
6296 This is the first GDB release which is accompanied by a matching testsuite.
6297 The testsuite requires installation of dejagnu, which should be available
6298 via ftp from most sites that carry GNU software.
6302 'Cfront' style demangling has had its name changed to 'ARM' style, to
6303 emphasize that it was written from the specifications in the C++ Annotated
6304 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6305 disclaimers, it still generated too much confusion with users attempting to
6306 use gdb with AT&T cfront.
6310 GDB now uses a standard remote interface to a simulator library.
6311 So far, the library contains simulators for the Zilog Z8001/2, the
6312 Hitachi H8/300, H8/500 and Super-H.
6314 * New targets supported
6316 H8/300 simulator h8300-hitachi-hms or h8300hms
6317 H8/500 simulator h8500-hitachi-hms or h8500hms
6318 SH simulator sh-hitachi-hms or sh
6319 Z8000 simulator z8k-zilog-none or z8ksim
6320 IDT MIPS board over serial line mips-idt-ecoff
6322 Cross-debugging to GO32 targets is supported. It requires a custom
6323 version of the i386-stub.c module which is integrated with the
6324 GO32 memory extender.
6326 * New remote protocols
6328 MIPS remote debugging protocol.
6330 * New source languages supported
6332 This version includes preliminary support for Chill, a Pascal like language
6333 used by telecommunications companies. Chill support is also being integrated
6334 into the GNU compiler, but we don't know when it will be publically available.
6337 *** Changes in GDB-4.8:
6339 * HP Precision Architecture supported
6341 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6342 version of this support was available as a set of patches from the
6343 University of Utah. GDB does not support debugging of programs
6344 compiled with the HP compiler, because HP will not document their file
6345 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6346 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6348 Many problems in the preliminary version have been fixed.
6350 * Faster and better demangling
6352 We have improved template demangling and fixed numerous bugs in the GNU style
6353 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6354 character types (wchar_t) are now supported. Demangling of each symbol is now
6355 only done once, and is cached when the symbol table for a file is read in.
6356 This results in a small increase in memory usage for C programs, a moderate
6357 increase in memory usage for C++ programs, and a fantastic speedup in
6360 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6361 from the specifications in the Annotated Reference Manual, which AT&T's
6362 compiler does not actually implement.
6364 * G++ multiple inheritance compiler problem
6366 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6367 inheritance lattices was reworked to properly discover ambiguities. We
6368 recently found an example which causes this new algorithm to fail in a
6369 very subtle way, producing bad debug information for those classes.
6370 The file 'gcc.patch' (in this directory) can be applied to gcc to
6371 circumvent the problem. A future GCC release will contain a complete
6374 The previous G++ debug info problem (mentioned below for the gdb-4.7
6375 release) is fixed in gcc version 2.3.2.
6377 * Improved configure script
6379 The `configure' script will now attempt to guess your system type if
6380 you don't supply a host system type. The old scheme of supplying a
6381 host system triplet is preferable over using this. All the magic is
6382 done in the new `config.guess' script. Examine it for details.
6384 We have also brought our configure script much more in line with the FSF's
6385 version. It now supports the --with-xxx options. In particular,
6386 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6387 The resulting GDB will not be able to read arbitrary object file formats --
6388 only the format ``expected'' to be used on the configured target system.
6389 We hope to make this the default in a future release.
6391 * Documentation improvements
6393 There's new internal documentation on how to modify GDB, and how to
6394 produce clean changes to the code. We implore people to read it
6395 before submitting changes.
6397 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6398 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6399 `info' files are also provided. To build `info' files from scratch,
6400 you will need the latest `makeinfo' release, which will be available in
6401 a future texinfo-X.Y release.
6403 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6404 We're not sure exactly which versions have this problem, but it has
6405 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6406 or better. If that isn't possible, there is a patch in
6407 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6408 around this problem.
6412 GDB now supports array constants that can be used in expressions typed in by
6413 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6414 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6417 The new directory `gdb/sparclite' contains a program that demonstrates
6418 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6420 * New native hosts supported
6422 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6423 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6425 * New targets supported
6427 AMD 29k family via UDI a29k-amd-udi or udi29k
6429 * New file formats supported
6431 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6432 HPUX core files, and SCO 3.2v2 core files.
6436 Attaching to processes now works again; thanks for the many bug reports.
6438 We have also stomped on a bunch of core dumps caused by
6439 printf_filtered("%s") problems.
6441 We eliminated a copyright problem on the rpc and ptrace header files
6442 for VxWorks, which was discovered at the last minute during the 4.7
6443 release. You should now be able to build a VxWorks GDB.
6445 You can now interrupt gdb while an attached process is running. This
6446 will cause the attached process to stop, and give control back to GDB.
6448 We fixed problems caused by using too many file descriptors
6449 for reading symbols from object files and libraries. This was
6450 especially a problem for programs that used many (~100) shared
6453 The `step' command now only enters a subroutine if there is line number
6454 information for the subroutine. Otherwise it acts like the `next'
6455 command. Previously, `step' would enter subroutines if there was
6456 any debugging information about the routine. This avoids problems
6457 when using `cc -g1' on MIPS machines.
6459 * Internal improvements
6461 GDB's internal interfaces have been improved to make it easier to support
6462 debugging of multiple languages in the future.
6464 GDB now uses a common structure for symbol information internally.
6465 Minimal symbols (derived from linkage symbols in object files), partial
6466 symbols (from a quick scan of debug information), and full symbols
6467 contain a common subset of information, making it easier to write
6468 shared code that handles any of them.
6470 * New command line options
6472 We now accept --silent as an alias for --quiet.
6476 The memory-mapped-malloc library is now licensed under the GNU Library
6477 General Public License.
6479 *** Changes in GDB-4.7:
6481 * Host/native/target split
6483 GDB has had some major internal surgery to untangle the support for
6484 hosts and remote targets. Now, when you configure GDB for a remote
6485 target, it will no longer load in all of the support for debugging
6486 local programs on the host. When fully completed and tested, this will
6487 ensure that arbitrary host/target combinations are possible.
6489 The primary conceptual shift is to separate the non-portable code in
6490 GDB into three categories. Host specific code is required any time GDB
6491 is compiled on that host, regardless of the target. Target specific
6492 code relates to the peculiarities of the target, but can be compiled on
6493 any host. Native specific code is everything else: it can only be
6494 built when the host and target are the same system. Child process
6495 handling and core file support are two common `native' examples.
6497 GDB's use of /proc for controlling Unix child processes is now cleaner.
6498 It has been split out into a single module under the `target_ops' vector,
6499 plus two native-dependent functions for each system that uses /proc.
6501 * New hosts supported
6503 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6504 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6505 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6507 * New targets supported
6509 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6510 68030 and CPU32 m68030-*-*, m68332-*-*
6512 * New native hosts supported
6514 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6515 (386bsd is not well tested yet)
6516 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6518 * New file formats supported
6520 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6521 supports reading of `a.out.adobe' object files, which are an a.out
6522 format extended with minimal information about multiple sections.
6526 `show copying' is the same as the old `info copying'.
6527 `show warranty' is the same as `info warrantee'.
6528 These were renamed for consistency. The old commands continue to work.
6530 `info handle' is a new alias for `info signals'.
6532 You can now define pre-command hooks, which attach arbitrary command
6533 scripts to any command. The commands in the hook will be executed
6534 prior to the user's command. You can also create a hook which will be
6535 executed whenever the program stops. See gdb.texinfo.
6539 We now deal with Cfront style name mangling, and can even extract type
6540 info from mangled symbols. GDB can automatically figure out which
6541 symbol mangling style your C++ compiler uses.
6543 Calling of methods and virtual functions has been improved as well.
6547 The crash that occured when debugging Sun Ansi-C compiled binaries is
6548 fixed. This was due to mishandling of the extra N_SO stabs output
6551 We also finally got Ultrix 4.2 running in house, and fixed core file
6552 support, with help from a dozen people on the net.
6554 John M. Farrell discovered that the reason that single-stepping was so
6555 slow on all of the Mips based platforms (primarily SGI and DEC) was
6556 that we were trying to demangle and lookup a symbol used for internal
6557 purposes on every instruction that was being stepped through. Changing
6558 the name of that symbol so that it couldn't be mistaken for a C++
6559 mangled symbol sped things up a great deal.
6561 Rich Pixley sped up symbol lookups in general by getting much smarter
6562 about when C++ symbol mangling is necessary. This should make symbol
6563 completion (TAB on the command line) much faster. It's not as fast as
6564 we'd like, but it's significantly faster than gdb-4.6.
6568 A new user controllable variable 'call_scratch_address' can
6569 specify the location of a scratch area to be used when GDB
6570 calls a function in the target. This is necessary because the
6571 usual method of putting the scratch area on the stack does not work
6572 in systems that have separate instruction and data spaces.
6574 We integrated changes to support the 29k UDI (Universal Debugger
6575 Interface), but discovered at the last minute that we didn't have all
6576 of the appropriate copyright paperwork. We are working with AMD to
6577 resolve this, and hope to have it available soon.
6581 We have sped up the remote serial line protocol, especially for targets
6582 with lots of registers. It now supports a new `expedited status' ('T')
6583 message which can be used in place of the existing 'S' status message.
6584 This allows the remote stub to send only the registers that GDB
6585 needs to make a quick decision about single-stepping or conditional
6586 breakpoints, eliminating the need to fetch the entire register set for
6587 each instruction being stepped through.
6589 The GDB remote serial protocol now implements a write-through cache for
6590 registers, only re-reading the registers if the target has run.
6592 There is also a new remote serial stub for SPARC processors. You can
6593 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6594 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6595 processor with a serial port.
6599 Configure.in files have become much easier to read and modify. A new
6600 `table driven' format makes it more obvious what configurations are
6601 supported, and what files each one uses.
6605 There is a new opcodes library which will eventually contain all of the
6606 disassembly routines and opcode tables. At present, it only contains
6607 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6608 disassembler (binutils/objdump) to share these routines.
6610 The libiberty library is now copylefted under the GNU Library General
6611 Public License. This allows more liberal use, and was done so libg++
6612 can use it. This makes no difference to GDB, since the Library License
6613 grants all the rights from the General Public License.
6617 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6618 reference to the stabs symbol info used by the debugger. It is (as far
6619 as we know) the only published document on this fascinating topic. We
6620 encourage you to read it, compare it to the stabs information on your
6621 system, and send improvements on the document in general (to
6622 bug-gdb@prep.ai.mit.edu).
6624 And, of course, many bugs have been fixed.
6627 *** Changes in GDB-4.6:
6629 * Better support for C++ function names
6631 GDB now accepts as input the "demangled form" of C++ overloaded function
6632 names and member function names, and can do command completion on such names
6633 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6634 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6635 Make use of command completion, it is your friend.
6637 GDB also now accepts a variety of C++ mangled symbol formats. They are
6638 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6639 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6640 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6641 for the list of formats.
6643 * G++ symbol mangling problem
6645 Recent versions of gcc have a bug in how they emit debugging information for
6646 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6647 directory) can be applied to gcc to fix the problem. Alternatively, if you
6648 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6649 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6650 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6653 * New 'maintenance' command
6655 All of the commands related to hacking GDB internals have been moved out of
6656 the main command set, and now live behind the 'maintenance' command. This
6657 can also be abbreviated as 'mt'. The following changes were made:
6659 dump-me -> maintenance dump-me
6660 info all-breakpoints -> maintenance info breakpoints
6661 printmsyms -> maintenance print msyms
6662 printobjfiles -> maintenance print objfiles
6663 printpsyms -> maintenance print psymbols
6664 printsyms -> maintenance print symbols
6666 The following commands are new:
6668 maintenance demangle Call internal GDB demangler routine to
6669 demangle a C++ link name and prints the result.
6670 maintenance print type Print a type chain for a given symbol
6672 * Change to .gdbinit file processing
6674 We now read the $HOME/.gdbinit file before processing the argv arguments
6675 (e.g. reading symbol files or core files). This allows global parameters to
6676 be set, which will apply during the symbol reading. The ./.gdbinit is still
6677 read after argv processing.
6679 * New hosts supported
6681 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6683 GNU/Linux support i386-unknown-linux or linux
6685 We are also including code to support the HP/PA running BSD and HPUX. This
6686 is almost guaranteed not to work, as we didn't have time to test or build it
6687 for this release. We are including it so that the more adventurous (or
6688 masochistic) of you can play with it. We also had major problems with the
6689 fact that the compiler that we got from HP doesn't support the -g option.
6692 * New targets supported
6694 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6696 * More smarts about finding #include files
6698 GDB now remembers the compilation directory for all include files, and for
6699 all files from which C is generated (like yacc and lex sources). This
6700 greatly improves GDB's ability to find yacc/lex sources, and include files,
6701 especially if you are debugging your program from a directory different from
6702 the one that contains your sources.
6704 We also fixed a bug which caused difficulty with listing and setting
6705 breakpoints in include files which contain C code. (In the past, you had to
6706 try twice in order to list an include file that you hadn't looked at before.)
6708 * Interesting infernals change
6710 GDB now deals with arbitrary numbers of sections, where the symbols for each
6711 section must be relocated relative to that section's landing place in the
6712 target's address space. This work was needed to support ELF with embedded
6713 stabs used by Solaris-2.0.
6715 * Bug fixes (of course!)
6717 There have been loads of fixes for the following things:
6718 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6719 i960, stabs, DOS(GO32), procfs, etc...
6721 See the ChangeLog for details.
6723 *** Changes in GDB-4.5:
6725 * New machines supported (host and target)
6727 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6729 SGI Irix-4.x mips-sgi-irix4 or iris4
6731 * New malloc package
6733 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6734 Mmalloc is capable of handling mutiple heaps of memory. It is also
6735 capable of saving a heap to a file, and then mapping it back in later.
6736 This can be used to greatly speedup the startup of GDB by using a
6737 pre-parsed symbol table which lives in a mmalloc managed heap. For
6738 more details, please read mmalloc/mmalloc.texi.
6742 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6743 'help info proc' for details.
6745 * MIPS ecoff symbol table format
6747 The code that reads MIPS symbol table format is now supported on all hosts.
6748 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6751 * File name changes for MS-DOS
6753 Many files in the config directories have been renamed to make it easier to
6754 support GDB on MS-DOSe systems (which have very restrictive file name
6755 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6756 environment) is close to working but has some remaining problems. Note
6757 that debugging of DOS programs is not supported, due to limitations
6758 in the ``operating system'', but it can be used to host cross-debugging.
6760 * Cross byte order fixes
6762 Many fixes have been made to support cross debugging of Sparc and MIPS
6763 targets from hosts whose byte order differs.
6765 * New -mapped and -readnow options
6767 If memory-mapped files are available on your system through the 'mmap'
6768 system call, you can use the -mapped option on the `file' or
6769 `symbol-file' commands to cause GDB to write the symbols from your
6770 program into a reusable file. If the program you are debugging is
6771 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6772 Future GDB debugging sessions will notice the presence of this file,
6773 and will quickly map in symbol information from it, rather than reading
6774 the symbol table from the executable program. Using the '-mapped'
6775 option in a GDB `file' or `symbol-file' command has the same effect as
6776 starting GDB with the '-mapped' command-line option.
6778 You can cause GDB to read the entire symbol table immediately by using
6779 the '-readnow' option with any of the commands that load symbol table
6780 information (or on the GDB command line). This makes the command
6781 slower, but makes future operations faster.
6783 The -mapped and -readnow options are typically combined in order to
6784 build a `fred.syms' file that contains complete symbol information.
6785 A simple GDB invocation to do nothing but build a `.syms' file for future
6788 gdb -batch -nx -mapped -readnow programname
6790 The `.syms' file is specific to the host machine on which GDB is run.
6791 It holds an exact image of GDB's internal symbol table. It cannot be
6792 shared across multiple host platforms.
6794 * longjmp() handling
6796 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6797 siglongjmp() without losing control. This feature has not yet been ported to
6798 all systems. It currently works on many 386 platforms, all MIPS-based
6799 platforms (SGI, DECstation, etc), and Sun3/4.
6803 Preliminary work has been put in to support the new Solaris OS from Sun. At
6804 this time, it can control and debug processes, but it is not capable of
6809 As always, many many bug fixes. The major areas were with g++, and mipsread.
6810 People using the MIPS-based platforms should experience fewer mysterious
6811 crashes and trashed symbol tables.
6813 *** Changes in GDB-4.4:
6815 * New machines supported (host and target)
6817 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6819 BSD Reno on Vax vax-dec-bsd
6820 Ultrix on Vax vax-dec-ultrix
6822 * New machines supported (target)
6824 AMD 29000 embedded, using EBMON a29k-none-none
6828 GDB continues to improve its handling of C++. `References' work better.
6829 The demangler has also been improved, and now deals with symbols mangled as
6830 per the Annotated C++ Reference Guide.
6832 GDB also now handles `stabs' symbol information embedded in MIPS
6833 `ecoff' symbol tables. Since the ecoff format was not easily
6834 extensible to handle new languages such as C++, this appeared to be a
6835 good way to put C++ debugging info into MIPS binaries. This option
6836 will be supported in the GNU C compiler, version 2, when it is
6839 * New features for SVR4
6841 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6842 shared libraries. Debugging dynamically linked programs should present
6843 only minor differences from debugging statically linked programs.
6845 The `info proc' command will print out information about any process
6846 on an SVR4 system (including the one you are debugging). At the moment,
6847 it prints the address mappings of the process.
6849 If you bring up GDB on another SVR4 system, please send mail to
6850 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6852 * Better dynamic linking support in SunOS
6854 Reading symbols from shared libraries which contain debugging symbols
6855 now works properly. However, there remain issues such as automatic
6856 skipping of `transfer vector' code during function calls, which
6857 make it harder to debug code in a shared library, than to debug the
6858 same code linked statically.
6862 GDB is now using the latest `getopt' routines from the FSF. This
6863 version accepts the -- prefix for options with long names. GDB will
6864 continue to accept the old forms (-option and +option) as well.
6865 Various single letter abbreviations for options have been explicity
6866 added to the option table so that they won't get overshadowed in the
6867 future by other options that begin with the same letter.
6871 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6872 Many assorted bugs have been handled. Many more remain to be handled.
6873 See the various ChangeLog files (primarily in gdb and bfd) for details.
6876 *** Changes in GDB-4.3:
6878 * New machines supported (host and target)
6880 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6881 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6882 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6884 * Almost SCO Unix support
6886 We had hoped to support:
6887 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6888 (except for core file support), but we discovered very late in the release
6889 that it has problems with process groups that render gdb unusable. Sorry
6890 about that. I encourage people to fix it and post the fixes.
6892 * Preliminary ELF and DWARF support
6894 GDB can read ELF object files on System V Release 4, and can handle
6895 debugging records for C, in DWARF format, in ELF files. This support
6896 is preliminary. If you bring up GDB on another SVR4 system, please
6897 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6902 GDB now uses the latest `readline' library. One user-visible change
6903 is that two tabs will list possible command completions, which previously
6904 required typing M-? (meta-question mark, or ESC ?).
6908 The `stepi' bug that many of you noticed has been squashed.
6909 Many bugs in C++ have been handled. Many more remain to be handled.
6910 See the various ChangeLog files (primarily in gdb and bfd) for details.
6912 * State of the MIPS world (in case you wondered):
6914 GDB can understand the symbol tables emitted by the compilers
6915 supplied by most vendors of MIPS-based machines, including DEC. These
6916 symbol tables are in a format that essentially nobody else uses.
6918 Some versions of gcc come with an assembler post-processor called
6919 mips-tfile. This program is required if you want to do source-level
6920 debugging of gcc-compiled programs. I believe FSF does not ship
6921 mips-tfile with gcc version 1, but it will eventually come with gcc
6924 Debugging of g++ output remains a problem. g++ version 1.xx does not
6925 really support it at all. (If you're lucky, you should be able to get
6926 line numbers and stack traces to work, but no parameters or local
6927 variables.) With some work it should be possible to improve the
6930 When gcc version 2 is released, you will have somewhat better luck.
6931 However, even then you will get confusing results for inheritance and
6934 We will eventually provide full debugging of g++ output on
6935 DECstations. This will probably involve some kind of stabs-in-ecoff
6936 encapulation, but the details have not been worked out yet.
6939 *** Changes in GDB-4.2:
6941 * Improved configuration
6943 Only one copy of `configure' exists now, and it is not self-modifying.
6944 Porting BFD is simpler.
6948 The `step' and `next' commands now only stop at the first instruction
6949 of a source line. This prevents the multiple stops that used to occur
6950 in switch statements, for-loops, etc. `Step' continues to stop if a
6951 function that has debugging information is called within the line.
6955 Lots of small bugs fixed. More remain.
6957 * New host supported (not target)
6959 Intel 386 PC clone running Mach i386-none-mach
6962 *** Changes in GDB-4.1:
6964 * Multiple source language support
6966 GDB now has internal scaffolding to handle several source languages.
6967 It determines the type of each source file from its filename extension,
6968 and will switch expression parsing and number formatting to match the
6969 language of the function in the currently selected stack frame.
6970 You can also specifically set the language to be used, with
6971 `set language c' or `set language modula-2'.
6975 GDB now has preliminary support for the GNU Modula-2 compiler,
6976 currently under development at the State University of New York at
6977 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6978 continue through the fall of 1991 and into 1992.
6980 Other Modula-2 compilers are currently not supported, and attempting to
6981 debug programs compiled with them will likely result in an error as the
6982 symbol table is read. Feel free to work on it, though!
6984 There are hooks in GDB for strict type checking and range checking,
6985 in the `Modula-2 philosophy', but they do not currently work.
6989 GDB can now write to executable and core files (e.g. patch
6990 a variable's value). You must turn this switch on, specify
6991 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6992 by assigning a new value to a variable. Modifications take
6995 * Automatic SunOS shared library reading
6997 When you run your program, GDB automatically determines where its
6998 shared libraries (if any) have been loaded, and reads their symbols.
6999 The `share' command is no longer needed. This also works when
7000 examining core files.
7004 You can specify the number of lines that the `list' command shows.
7007 * New machines supported (host and target)
7009 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7010 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7011 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7013 * New hosts supported (not targets)
7015 IBM RT/PC: romp-ibm-aix or rtpc
7017 * New targets supported (not hosts)
7019 AMD 29000 embedded with COFF a29k-none-coff
7020 AMD 29000 embedded with a.out a29k-none-aout
7021 Ultracomputer remote kernel debug a29k-nyu-kern
7023 * New remote interfaces
7029 *** Changes in GDB-4.0:
7033 Wide output is wrapped at good places to make the output more readable.
7035 Gdb now supports cross-debugging from a host machine of one type to a
7036 target machine of another type. Communication with the target system
7037 is over serial lines. The ``target'' command handles connecting to the
7038 remote system; the ``load'' command will download a program into the
7039 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7040 also supports debugging of realtime processes running under VxWorks,
7041 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7042 stub on the target system.
7044 New CPUs supported include the AMD 29000 and Intel 960.
7046 GDB now reads object files and symbol tables via a ``binary file''
7047 library, which allows a single copy of GDB to debug programs of multiple
7048 object file types such as a.out and coff.
7050 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7051 refcard.dvi and refcard.ps are available to format it).
7054 * Control-Variable user interface simplified
7056 All variables that control the operation of the debugger can be set
7057 by the ``set'' command, and displayed by the ``show'' command.
7059 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7060 ``Show prompt'' produces the response:
7061 Gdb's prompt is new-gdb=>.
7063 What follows are the NEW set commands. The command ``help set'' will
7064 print a complete list of old and new set commands. ``help set FOO''
7065 will give a longer description of the variable FOO. ``show'' will show
7066 all of the variable descriptions and their current settings.
7068 confirm on/off: Enables warning questions for operations that are
7069 hard to recover from, e.g. rerunning the program while
7070 it is already running. Default is ON.
7072 editing on/off: Enables EMACS style command line editing
7073 of input. Previous lines can be recalled with
7074 control-P, the current line can be edited with control-B,
7075 you can search for commands with control-R, etc.
7078 history filename NAME: NAME is where the gdb command history
7079 will be stored. The default is .gdb_history,
7080 or the value of the environment variable
7083 history size N: The size, in commands, of the command history. The
7084 default is 256, or the value of the environment variable
7087 history save on/off: If this value is set to ON, the history file will
7088 be saved after exiting gdb. If set to OFF, the
7089 file will not be saved. The default is OFF.
7091 history expansion on/off: If this value is set to ON, then csh-like
7092 history expansion will be performed on
7093 command line input. The default is OFF.
7095 radix N: Sets the default radix for input and output. It can be set
7096 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7097 in the current radix, so "set radix 10" is always a no-op.
7099 height N: This integer value is the number of lines on a page. Default
7100 is 24, the current `stty rows'' setting, or the ``li#''
7101 setting from the termcap entry matching the environment
7104 width N: This integer value is the number of characters on a line.
7105 Default is 80, the current `stty cols'' setting, or the ``co#''
7106 setting from the termcap entry matching the environment
7109 Note: ``set screensize'' is obsolete. Use ``set height'' and
7110 ``set width'' instead.
7112 print address on/off: Print memory addresses in various command displays,
7113 such as stack traces and structure values. Gdb looks
7114 more ``symbolic'' if you turn this off; it looks more
7115 ``machine level'' with it on. Default is ON.
7117 print array on/off: Prettyprint arrays. New convenient format! Default
7120 print demangle on/off: Print C++ symbols in "source" form if on,
7123 print asm-demangle on/off: Same, for assembler level printouts
7126 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7129 * Support for Epoch Environment.
7131 The epoch environment is a version of Emacs v18 with windowing. One
7132 new command, ``inspect'', is identical to ``print'', except that if you
7133 are running in the epoch environment, the value is printed in its own
7137 * Support for Shared Libraries
7139 GDB can now debug programs and core files that use SunOS shared libraries.
7140 Symbols from a shared library cannot be referenced
7141 before the shared library has been linked with the program (this
7142 happens after you type ``run'' and before the function main() is entered).
7143 At any time after this linking (including when examining core files
7144 from dynamically linked programs), gdb reads the symbols from each
7145 shared library when you type the ``sharedlibrary'' command.
7146 It can be abbreviated ``share''.
7148 sharedlibrary REGEXP: Load shared object library symbols for files
7149 matching a unix regular expression. No argument
7150 indicates to load symbols for all shared libraries.
7152 info sharedlibrary: Status of loaded shared libraries.
7157 A watchpoint stops execution of a program whenever the value of an
7158 expression changes. Checking for this slows down execution
7159 tremendously whenever you are in the scope of the expression, but is
7160 quite useful for catching tough ``bit-spreader'' or pointer misuse
7161 problems. Some machines such as the 386 have hardware for doing this
7162 more quickly, and future versions of gdb will use this hardware.
7164 watch EXP: Set a watchpoint (breakpoint) for an expression.
7166 info watchpoints: Information about your watchpoints.
7168 delete N: Deletes watchpoint number N (same as breakpoints).
7169 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7170 enable N: Re-enables watchpoint number N (same as breakpoints).
7173 * C++ multiple inheritance
7175 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7178 * C++ exception handling
7180 Gdb now supports limited C++ exception handling. Besides the existing
7181 ability to breakpoint on an exception handler, gdb can breakpoint on
7182 the raising of an exception (before the stack is peeled back to the
7185 catch FOO: If there is a FOO exception handler in the dynamic scope,
7186 set a breakpoint to catch exceptions which may be raised there.
7187 Multiple exceptions (``catch foo bar baz'') may be caught.
7189 info catch: Lists all exceptions which may be caught in the
7190 current stack frame.
7193 * Minor command changes
7195 The command ``call func (arg, arg, ...)'' now acts like the print
7196 command, except it does not print or save a value if the function's result
7197 is void. This is similar to dbx usage.
7199 The ``up'' and ``down'' commands now always print the frame they end up
7200 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7201 frames without printing.
7203 * New directory command
7205 'dir' now adds directories to the FRONT of the source search path.
7206 The path starts off empty. Source files that contain debug information
7207 about the directory in which they were compiled can be found even
7208 with an empty path; Sun CC and GCC include this information. If GDB can't
7209 find your source file in the current directory, type "dir .".
7211 * Configuring GDB for compilation
7213 For normal use, type ``./configure host''. See README or gdb.texinfo
7216 GDB now handles cross debugging. If you are remotely debugging between
7217 two different machines, type ``./configure host -target=targ''.
7218 Host is the machine where GDB will run; targ is the machine
7219 where the program that you are debugging will run.