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 * GDB in batch mode now exits with status 1 if the last command to be
28 * Changes to the "frame", "select-frame", and "info frame" CLI
29 commands. These commands all now take a frame specification which
30 is either a frame level, or one of the keywords 'level', 'address',
31 'function', or 'view' followed by a parameter. Selecting a frame by
32 address, or viewing a frame outside the current backtrace now
33 requires the use of a keyword. Selecting a frame by level is
34 unchanged. The MI comment "-stack-select-frame" is unchanged.
42 set debug compile-cplus-types
43 show debug compile-cplus-types
44 Control the display of debug output about type conversion in the
45 C++ compile feature. Commands have no effect while compiliong
50 Control whether debug output about files/functions skipping is
53 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
54 Apply a command to some frames.
55 FLAG arguments allow to control what output to produce and how to handle
56 errors raised when applying COMMAND to a frame.
59 Apply a command to all threads (ignoring errors and empty output).
60 Shortcut for 'thread apply all -s COMMAND'.
63 Apply a command to all frames (ignoring errors and empty output).
64 Shortcut for 'frame apply all -s COMMAND'.
67 Apply a command to all frames of all threads (ignoring errors and empty
69 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
71 maint set dwarf unwinders (on|off)
72 maint show dwarf unwinders
73 Control whether DWARF unwinders can be used.
76 Display a list of open files for a process.
80 target remote FILENAME
81 target extended-remote FILENAME
82 If FILENAME is a Unix domain socket, GDB will attempt to connect
83 to this socket instead of opening FILENAME as a character device.
85 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
86 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
87 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
88 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
89 These commands can now print only the searched entities
90 matching the provided regexp(s), giving a condition
91 on the entity names or entity types. The flag -q disables
92 printing headers or informations messages.
94 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
95 The 'thread apply' command accepts new FLAG arguments.
96 FLAG arguments allow to control what output to produce and how to handle
97 errors raised when applying COMMAND to a thread.
99 set tui tab-width NCHARS
100 show tui tab-width NCHARS
101 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
105 ** The '-data-disassemble' MI command now accepts an '-a' option to
106 disassemble the whole function surrounding the given program
107 counter value or function name. Support for this feature can be
108 verified by using the "-list-features" command, which should
109 contain "data-disassemble-a-option".
111 ** Command responses and notifications that include a frame now include
112 the frame's architecture in a new "arch" attribute.
114 * New native configurations
116 GNU/Linux/RISC-V riscv*-*-linux*
117 FreeBSD/riscv riscv*-*-freebsd*
121 GNU/Linux/RISC-V riscv*-*-linux*
123 CSKY GNU/LINUX csky*-*-linux
124 FreeBSD/riscv riscv*-*-freebsd*
128 ** The gdb.Inferior type has a new 'progspace' property, which is the program
129 space associated to that inferior.
131 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
132 of objfiles associated to that program space.
134 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
135 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
138 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
139 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
140 correct and did not work properly.
146 Enable or disable the undefined behavior sanitizer. This is
147 disabled by default, but passing --enable-ubsan=yes or
148 --enable-ubsan=auto to configure will enable it. Enabling this can
149 cause a performance penalty. The undefined behavior sanitizer was
150 first introduced in GCC 4.9.
152 *** Changes in GDB 8.2
154 * The 'set disassembler-options' command now supports specifying options
157 * The 'symbol-file' command now accepts an '-o' option to add a relative
158 offset to all sections.
160 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
161 a relative offset to all sections, but it allows to override the load
162 address of individual sections using '-s'.
164 * The 'add-symbol-file' command no longer requires the second argument
165 (address of the text section).
167 * The endianness used with the 'set endian auto' mode in the absence of
168 an executable selected for debugging is now the last endianness chosen
169 either by one of the 'set endian big' and 'set endian little' commands
170 or by inferring from the last executable used, rather than the startup
173 * The pager now allows a "c" response, meaning to disable the pager
174 for the rest of the current command.
176 * The commands 'info variables/functions/types' now show the source line
177 numbers of symbol definitions when available.
179 * 'info proc' now works on running processes on FreeBSD systems and core
180 files created on FreeBSD systems.
182 * C expressions can now use _Alignof, and C++ expressions can now use
185 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
186 the vector length while the process is running.
192 Control display of debugging info regarding the FreeBSD native target.
194 set|show varsize-limit
195 This new setting allows the user to control the maximum size of Ada
196 objects being printed when those objects have a variable type,
197 instead of that maximum size being hardcoded to 65536 bytes.
199 set|show record btrace cpu
200 Controls the processor to be used for enabling errata workarounds for
203 maint check libthread-db
204 Run integrity checks on the current inferior's thread debugging
207 maint set check-libthread-db (on|off)
208 maint show check-libthread-db
209 Control whether to run integrity checks on inferior specific thread
210 debugging libraries as they are loaded. The default is not to
215 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
217 ** The commands attached to a breakpoint can be set by assigning to
218 the breakpoint's "commands" field.
220 ** gdb.execute can now execute multi-line gdb commands.
222 ** The new functions gdb.convenience_variable and
223 gdb.set_convenience_variable can be used to get and set the value
224 of convenience variables.
226 ** A gdb.Parameter will no longer print the "set" help text on an
227 ordinary "set"; instead by default a "set" will be silent unless
228 the get_set_string method returns a non-empty string.
232 RiscV ELF riscv*-*-elf
234 * Removed targets and native configurations
236 m88k running OpenBSD m88*-*-openbsd*
237 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
238 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
239 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
241 * Aarch64/Linux hardware watchpoints improvements
243 Hardware watchpoints on unaligned addresses are now properly
244 supported when running Linux kernel 4.10 or higher: read and access
245 watchpoints are no longer spuriously missed, and all watchpoints
246 lengths between 1 and 8 bytes are supported. On older kernels,
247 watchpoints set on unaligned addresses are no longer missed, with
248 the tradeoff that there is a possibility of false hits being
253 --enable-codesign=CERT
254 This can be used to invoke "codesign -s CERT" after building gdb.
255 This option is useful on macOS, where code signing is required for
256 gdb to work properly.
258 --disable-gdbcli has been removed
259 This is now silently accepted, but does nothing.
261 *** Changes in GDB 8.1
263 * GDB now supports dynamically creating arbitrary register groups specified
264 in XML target descriptions. This allows for finer grain grouping of
265 registers on systems with a large amount of registers.
267 * The 'ptype' command now accepts a '/o' flag, which prints the
268 offsets and sizes of fields in a struct, like the pahole(1) tool.
270 * New "--readnever" command line option instructs GDB to not read each
271 symbol file's symbolic debug information. This makes startup faster
272 but at the expense of not being able to perform symbolic debugging.
273 This option is intended for use cases where symbolic debugging will
274 not be used, e.g., when you only need to dump the debuggee's core.
276 * GDB now uses the GNU MPFR library, if available, to emulate target
277 floating-point arithmetic during expression evaluation when the target
278 uses different floating-point formats than the host. At least version
279 3.1 of GNU MPFR is required.
281 * GDB now supports access to the guarded-storage-control registers and the
282 software-based guarded-storage broadcast control registers on IBM z14.
284 * On Unix systems, GDB now supports transmitting environment variables
285 that are to be set or unset to GDBserver. These variables will
286 affect the environment to be passed to the remote inferior.
288 To inform GDB of environment variables that are to be transmitted to
289 GDBserver, use the "set environment" command. Only user set
290 environment variables are sent to GDBserver.
292 To inform GDB of environment variables that are to be unset before
293 the remote inferior is started by the GDBserver, use the "unset
294 environment" command.
296 * Completion improvements
298 ** GDB can now complete function parameters in linespecs and
299 explicit locations without quoting. When setting breakpoints,
300 quoting around functions names to help with TAB-completion is
301 generally no longer necessary. For example, this now completes
304 (gdb) b function(in[TAB]
305 (gdb) b function(int)
307 Related, GDB is no longer confused with completing functions in
308 C++ anonymous namespaces:
311 (gdb) b (anonymous namespace)::[TAB][TAB]
312 (anonymous namespace)::a_function()
313 (anonymous namespace)::b_function()
315 ** GDB now has much improved linespec and explicit locations TAB
316 completion support, that better understands what you're
317 completing and offers better suggestions. For example, GDB no
318 longer offers data symbols as possible completions when you're
319 setting a breakpoint.
321 ** GDB now TAB-completes label symbol names.
323 ** The "complete" command now mimics TAB completion accurately.
325 * New command line options (gcore)
328 Dump all memory mappings.
330 * Breakpoints on C++ functions are now set on all scopes by default
332 By default, breakpoints on functions/methods are now interpreted as
333 specifying all functions with the given name ignoring missing
334 leading scopes (namespaces and classes).
336 For example, assuming a C++ program with symbols named:
341 both commands "break func()" and "break B::func()" set a breakpoint
344 You can use the new flag "-qualified" to override this. This makes
345 GDB interpret the specified function name as a complete
346 fully-qualified name instead. For example, using the same C++
347 program, the "break -q B::func" command sets a breakpoint on
348 "B::func", only. A parameter has been added to the Python
349 gdb.Breakpoint constructor to achieve the same result when creating
350 a breakpoint from Python.
352 * Breakpoints on functions marked with C++ ABI tags
354 GDB can now set breakpoints on functions marked with C++ ABI tags
355 (e.g., [abi:cxx11]). See here for a description of ABI tags:
356 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
358 Functions with a C++11 abi tag are demangled/displayed like this:
360 function[abi:cxx11](int)
363 You can now set a breakpoint on such functions simply as if they had
366 (gdb) b function(int)
368 Or if you need to disambiguate between tags, like:
370 (gdb) b function[abi:other_tag](int)
372 Tab completion was adjusted accordingly as well.
376 ** New events gdb.new_inferior, gdb.inferior_deleted, and
377 gdb.new_thread are emitted. See the manual for further
378 description of these.
380 ** A new function, "gdb.rbreak" has been added to the Python API.
381 This function allows the setting of a large number of breakpoints
382 via a regex pattern in Python. See the manual for further details.
384 ** Python breakpoints can now accept explicit locations. See the
385 manual for a further description of this feature.
388 * New features in the GDB remote stub, GDBserver
390 ** GDBserver is now able to start inferior processes with a
391 specified initial working directory.
393 The user can set the desired working directory to be used from
394 GDB using the new "set cwd" command.
396 ** New "--selftest" command line option runs some GDBserver self
397 tests. These self tests are disabled in releases.
399 ** On Unix systems, GDBserver now does globbing expansion and variable
400 substitution in inferior command line arguments.
402 This is done by starting inferiors using a shell, like GDB does.
403 See "set startup-with-shell" in the user manual for how to disable
404 this from GDB when using "target extended-remote". When using
405 "target remote", you can disable the startup with shell by using the
406 new "--no-startup-with-shell" GDBserver command line option.
408 ** On Unix systems, GDBserver now supports receiving environment
409 variables that are to be set or unset from GDB. These variables
410 will affect the environment to be passed to the inferior.
412 * When catching an Ada exception raised with a message, GDB now prints
413 the message in the catchpoint hit notification. In GDB/MI mode, that
414 information is provided as an extra field named "exception-message"
415 in the *stopped notification.
417 * Trait objects can now be inspected When debugging Rust code. This
418 requires compiler support which will appear in Rust 1.24.
422 QEnvironmentHexEncoded
423 Inform GDBserver of an environment variable that is to be passed to
424 the inferior when starting it.
427 Inform GDBserver of an environment variable that is to be unset
428 before starting the remote inferior.
431 Inform GDBserver that the environment should be reset (i.e.,
432 user-set environment variables should be unset).
435 Indicates whether the inferior must be started with a shell or not.
438 Tell GDBserver that the inferior to be started should use a specific
441 * The "maintenance print c-tdesc" command now takes an optional
442 argument which is the file name of XML target description.
444 * The "maintenance selftest" command now takes an optional argument to
445 filter the tests to be run.
447 * The "enable", and "disable" commands now accept a range of
448 breakpoint locations, e.g. "enable 1.3-5".
453 Set and show the current working directory for the inferior.
456 Set and show compilation command used for compiling and injecting code
457 with the 'compile' commands.
459 set debug separate-debug-file
460 show debug separate-debug-file
461 Control the display of debug output about separate debug file search.
463 set dump-excluded-mappings
464 show dump-excluded-mappings
465 Control whether mappings marked with the VM_DONTDUMP flag should be
466 dumped when generating a core file.
469 List the registered selftests.
472 Start the debugged program stopping at the first instruction.
475 Control display of debugging messages related to OpenRISC targets.
477 set|show print type nested-type-limit
478 Set and show the limit of nesting level for nested types that the
479 type printer will show.
481 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
484 * Safer/improved support for debugging with no debug info
486 GDB no longer assumes functions with no debug information return
489 This means that GDB now refuses to call such functions unless you
490 tell it the function's type, by either casting the call to the
491 declared return type, or by casting the function to a function
492 pointer of the right type, and calling that:
494 (gdb) p getenv ("PATH")
495 'getenv' has unknown return type; cast the call to its declared return type
496 (gdb) p (char *) getenv ("PATH")
497 $1 = 0x7fffffffe "/usr/local/bin:/"...
498 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
499 $2 = 0x7fffffffe "/usr/local/bin:/"...
501 Similarly, GDB no longer assumes that global variables with no debug
502 info have type 'int', and refuses to print the variable's value
503 unless you tell it the variable's type:
506 'var' has unknown type; cast it to its declared type
510 * New native configurations
512 FreeBSD/aarch64 aarch64*-*-freebsd*
513 FreeBSD/arm arm*-*-freebsd*
517 FreeBSD/aarch64 aarch64*-*-freebsd*
518 FreeBSD/arm arm*-*-freebsd*
519 OpenRISC ELF or1k*-*-elf
521 * Removed targets and native configurations
523 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
525 *** Changes in GDB 8.0
527 * GDB now supports access to the PKU register on GNU/Linux. The register is
528 added by the Memory Protection Keys for Userspace feature which will be
529 available in future Intel CPUs.
531 * GDB now supports C++11 rvalue references.
535 ** New functions to start, stop and access a running btrace recording.
536 ** Rvalue references are now supported in gdb.Type.
538 * GDB now supports recording and replaying rdrand and rdseed Intel 64
541 * Building GDB and GDBserver now requires a C++11 compiler.
543 For example, GCC 4.8 or later.
545 It is no longer possible to build GDB or GDBserver with a C
546 compiler. The --disable-build-with-cxx configure option has been
549 * Building GDB and GDBserver now requires GNU make >= 3.81.
551 It is no longer supported to build GDB or GDBserver with another
552 implementation of the make program or an earlier version of GNU make.
554 * Native debugging on MS-Windows supports command-line redirection
556 Command-line arguments used for starting programs on MS-Windows can
557 now include redirection symbols supported by native Windows shells,
558 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
559 as "run", "start", and "set args", as well as the corresponding MI
562 * Support for thread names on MS-Windows.
564 GDB now catches and handles the special exception that programs
565 running on MS-Windows use to assign names to threads in the
568 * Support for Java programs compiled with gcj has been removed.
570 * User commands now accept an unlimited number of arguments.
571 Previously, only up to 10 was accepted.
573 * The "eval" command now expands user-defined command arguments.
575 This makes it easier to process a variable number of arguments:
580 eval "print $arg%d", $i
585 * Target descriptions can now describe registers for sparc32 and sparc64.
587 * GDB now supports DWARF version 5 (debug information format).
588 Its .debug_names index is not yet supported.
590 * New native configurations
592 FreeBSD/mips mips*-*-freebsd
596 Synopsys ARC arc*-*-elf32
597 FreeBSD/mips mips*-*-freebsd
599 * Removed targets and native configurations
601 Alpha running FreeBSD alpha*-*-freebsd*
602 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
607 Erases all the flash memory regions reported by the target.
609 maint print arc arc-instruction address
610 Print internal disassembler information about instruction at a given address.
614 set disassembler-options
615 show disassembler-options
616 Controls the passing of target specific information to the disassembler.
617 If it is necessary to specify more than one disassembler option then
618 multiple options can be placed together into a comma separated list.
619 The default value is the empty string. Currently, the only supported
620 targets are ARM, PowerPC and S/390.
625 Erases all the flash memory regions reported by the target. This is
626 equivalent to the CLI command flash-erase.
628 -file-list-shared-libraries
629 List the shared libraries in the program. This is
630 equivalent to the CLI command "info shared".
633 Catchpoints stopping the program when Ada exceptions are
634 handled. This is equivalent to the CLI command "catch handlers".
636 *** Changes in GDB 7.12
638 * GDB and GDBserver now build with a C++ compiler by default.
640 The --enable-build-with-cxx configure option is now enabled by
641 default. One must now explicitly configure with
642 --disable-build-with-cxx in order to build with a C compiler. This
643 option will be removed in a future release.
645 * GDBserver now supports recording btrace without maintaining an active
648 * GDB now supports a negative repeat count in the 'x' command to examine
649 memory backward from the given address. For example:
652 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
653 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
654 (gdb) x/-5i 0x0000000000400580
655 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
656 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
657 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
658 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
659 0x40057b <main(int, char**)+25>:
660 callq 0x400536 <Func1(int, char const*)>
662 * Fortran: Support structures with fields of dynamic types and
663 arrays of dynamic types.
665 * The symbol dumping maintenance commands have new syntax.
666 maint print symbols [-pc address] [--] [filename]
667 maint print symbols [-objfile objfile] [-source source] [--] [filename]
668 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
669 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
670 maint print msymbols [-objfile objfile] [--] [filename]
672 * GDB now supports multibit bitfields and enums in target register
675 * New Python-based convenience function $_as_string(val), which returns
676 the textual representation of a value. This function is especially
677 useful to obtain the text label of an enum value.
679 * Intel MPX bound violation handling.
681 Segmentation faults caused by a Intel MPX boundary violation
682 now display the kind of violation (upper or lower), the memory
683 address accessed and the memory bounds, along with the usual
684 signal received and code location.
688 Program received signal SIGSEGV, Segmentation fault
689 Upper bound violation while accessing address 0x7fffffffc3b3
690 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
691 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
693 * Rust language support.
694 GDB now supports debugging programs written in the Rust programming
695 language. See https://www.rust-lang.org/ for more information about
698 * Support for running interpreters on specified input/output devices
700 GDB now supports a new mechanism that allows frontends to provide
701 fully featured GDB console views, as a better alternative to
702 building such views on top of the "-interpreter-exec console"
703 command. See the new "new-ui" command below. With that command,
704 frontends can now start GDB in the traditional command-line mode
705 running in an embedded terminal emulator widget, and create a
706 separate MI interpreter running on a specified i/o device. In this
707 way, GDB handles line editing, history, tab completion, etc. in the
708 console all by itself, and the GUI uses the separate MI interpreter
709 for its own control and synchronization, invisible to the command
712 * The "catch syscall" command catches groups of related syscalls.
714 The "catch syscall" command now supports catching a group of related
715 syscalls using the 'group:' or 'g:' prefix.
720 skip -gfile file-glob-pattern
721 skip -function function
722 skip -rfunction regular-expression
723 A generalized form of the skip command, with new support for
724 glob-style file names and regular expressions for function names.
725 Additionally, a file spec and a function spec may now be combined.
727 maint info line-table REGEXP
728 Display the contents of GDB's internal line table data struture.
731 Run any GDB unit tests that were compiled in.
734 Start a new user interface instance running INTERP as interpreter,
735 using the TTY file for input/output.
739 ** gdb.Breakpoint objects have a new attribute "pending", which
740 indicates whether the breakpoint is pending.
741 ** Three new breakpoint-related events have been added:
742 gdb.breakpoint_created, gdb.breakpoint_modified, and
743 gdb.breakpoint_deleted.
746 Signal ("set") the given MS-Windows event object. This is used in
747 conjunction with the Windows JIT debugging (AeDebug) support, where
748 the OS suspends a crashing process until a debugger can attach to
749 it. Resuming the crashing process, in order to debug it, is done by
752 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
753 was added in GDBserver, including JIT compiling fast tracepoint's
754 conditional expression bytecode into native code.
756 * Support for various remote target protocols and ROM monitors has
759 target m32rsdi Remote M32R debugging over SDI
760 target mips MIPS remote debugging protocol
761 target pmon PMON ROM monitor
762 target ddb NEC's DDB variant of PMON for Vr4300
763 target rockhopper NEC RockHopper variant of PMON
764 target lsi LSI variant of PMO
766 * Support for tracepoints and fast tracepoints on powerpc-linux,
767 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
768 including JIT compiling fast tracepoint's conditional expression
769 bytecode into native code.
771 * MI async record =record-started now includes the method and format used for
772 recording. For example:
774 =record-started,thread-group="i1",method="btrace",format="bts"
776 * MI async record =thread-selected now includes the frame field. For example:
778 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
782 Andes NDS32 nds32*-*-elf
784 *** Changes in GDB 7.11
786 * GDB now supports debugging kernel-based threads on FreeBSD.
788 * Per-inferior thread numbers
790 Thread numbers are now per inferior instead of global. If you're
791 debugging multiple inferiors, GDB displays thread IDs using a
792 qualified INF_NUM.THR_NUM form. For example:
796 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
797 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
798 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
799 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
801 As consequence, thread numbers as visible in the $_thread
802 convenience variable and in Python's InferiorThread.num attribute
803 are no longer unique between inferiors.
805 GDB now maintains a second thread ID per thread, referred to as the
806 global thread ID, which is the new equivalent of thread numbers in
807 previous releases. See also $_gthread below.
809 For backwards compatibility, MI's thread IDs always refer to global
812 * Commands that accept thread IDs now accept the qualified
813 INF_NUM.THR_NUM form as well. For example:
816 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
819 * In commands that accept a list of thread IDs, you can now refer to
820 all threads of an inferior using a star wildcard. GDB accepts
821 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
822 refer to all threads of the current inferior. For example, "info
825 * You can use "info threads -gid" to display the global thread ID of
828 * The new convenience variable $_gthread holds the global number of
831 * The new convenience variable $_inferior holds the number of the
834 * GDB now displays the ID and name of the thread that hit a breakpoint
835 or received a signal, if your program is multi-threaded. For
838 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
839 Thread 1 "main" received signal SIGINT, Interrupt.
841 * Record btrace now supports non-stop mode.
843 * Support for tracepoints on aarch64-linux was added in GDBserver.
845 * The 'record instruction-history' command now indicates speculative execution
846 when using the Intel Processor Trace recording format.
848 * GDB now allows users to specify explicit locations, bypassing
849 the linespec parser. This feature is also available to GDB/MI
852 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
853 GDB now is able to debug both AArch64 applications and ARM applications
856 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
857 including JIT compiling fast tracepoint's conditional expression bytecode
860 * GDB now supports displaced stepping on AArch64 GNU/Linux.
862 * "info threads", "info inferiors", "info display", "info checkpoints"
863 and "maint info program-spaces" now list the corresponding items in
864 ascending ID order, for consistency with all other "info" commands.
866 * In Ada, the overloads selection menu has been enhanced to display the
867 parameter types and the return types for the matching overloaded subprograms.
871 maint set target-non-stop (on|off|auto)
872 maint show target-non-stop
873 Control whether GDB targets always operate in non-stop mode even if
874 "set non-stop" is "off". The default is "auto", meaning non-stop
875 mode is enabled if supported by the target.
877 maint set bfd-sharing
878 maint show bfd-sharing
879 Control the reuse of bfd objects.
883 Control display of debugging info regarding bfd caching.
887 Control display of debugging info regarding FreeBSD threads.
889 set remote multiprocess-extensions-packet
890 show remote multiprocess-extensions-packet
891 Set/show the use of the remote protocol multiprocess extensions.
893 set remote thread-events
894 show remote thread-events
895 Set/show the use of thread create/exit events.
897 set ada print-signatures on|off
898 show ada print-signatures"
899 Control whether parameter types and return types are displayed in overloads
900 selection menus. It is activaled (@code{on}) by default.
904 Controls the maximum size of memory, in bytes, that GDB will
905 allocate for value contents. Prevents incorrect programs from
906 causing GDB to allocate overly large buffers. Default is 64k.
908 * The "disassemble" command accepts a new modifier: /s.
909 It prints mixed source+disassembly like /m with two differences:
910 - disassembled instructions are now printed in program order, and
911 - and source for all relevant files is now printed.
912 The "/m" option is now considered deprecated: its "source-centric"
913 output hasn't proved useful in practice.
915 * The "record instruction-history" command accepts a new modifier: /s.
916 It behaves exactly like /m and prints mixed source+disassembly.
918 * The "set scheduler-locking" command supports a new mode "replay".
919 It behaves like "off" in record mode and like "on" in replay mode.
921 * Support for various ROM monitors has been removed:
923 target dbug dBUG ROM monitor for Motorola ColdFire
924 target picobug Motorola picobug monitor
925 target dink32 DINK32 ROM monitor for PowerPC
926 target m32r Renesas M32R/D ROM monitor
927 target mon2000 mon2000 ROM monitor
928 target ppcbug PPCBUG ROM monitor for PowerPC
930 * Support for reading/writing memory and extracting values on architectures
931 whose memory is addressable in units of any integral multiple of 8 bits.
934 Allows to break when an Ada exception is handled.
939 Indicates that an exec system call was executed.
941 exec-events feature in qSupported
942 The qSupported packet allows GDB to request support for exec
943 events using the new 'gdbfeature' exec-event, and the qSupported
944 response can contain the corresponding 'stubfeature'. Set and
945 show commands can be used to display whether these features are enabled.
948 Equivalent to interrupting with the ^C character, but works in
951 thread created stop reason (T05 create:...)
952 Indicates that the thread was just created and is stopped at entry.
954 thread exit stop reply (w exitcode;tid)
955 Indicates that the thread has terminated.
958 Enables/disables thread create and exit event reporting. For
959 example, this is used in non-stop mode when GDB stops a set of
960 threads and synchronously waits for the their corresponding stop
961 replies. Without exit events, if one of the threads exits, GDB
962 would hang forever not knowing that it should no longer expect a
963 stop for that same thread.
966 Indicates that there are no resumed threads left in the target (all
967 threads are stopped). The remote stub reports support for this stop
968 reply to GDB's qSupported query.
971 Enables/disables catching syscalls from the inferior process.
972 The remote stub reports support for this packet to GDB's qSupported query.
974 syscall_entry stop reason
975 Indicates that a syscall was just called.
977 syscall_return stop reason
978 Indicates that a syscall just returned.
980 * Extended-remote exec events
982 ** GDB now has support for exec events on extended-remote Linux targets.
983 For such targets with Linux kernels 2.5.46 and later, this enables
984 follow-exec-mode and exec catchpoints.
986 set remote exec-event-feature-packet
987 show remote exec-event-feature-packet
988 Set/show the use of the remote exec event feature.
990 * Thread names in remote protocol
992 The reply to qXfer:threads:read may now include a name attribute for each
995 * Target remote mode fork and exec events
997 ** GDB now has support for fork and exec events on target remote mode
998 Linux targets. For such targets with Linux kernels 2.5.46 and later,
999 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1000 fork and exec catchpoints.
1002 * Remote syscall events
1004 ** GDB now has support for catch syscall on remote Linux targets,
1005 currently enabled on x86/x86_64 architectures.
1007 set remote catch-syscall-packet
1008 show remote catch-syscall-packet
1009 Set/show the use of the remote catch syscall feature.
1013 ** The -var-set-format command now accepts the zero-hexadecimal
1014 format. It outputs data in hexadecimal format with zero-padding on the
1019 ** gdb.InferiorThread objects have a new attribute "global_num",
1020 which refers to the thread's global thread ID. The existing
1021 "num" attribute now refers to the thread's per-inferior number.
1022 See "Per-inferior thread numbers" above.
1023 ** gdb.InferiorThread objects have a new attribute "inferior", which
1024 is the Inferior object the thread belongs to.
1026 *** Changes in GDB 7.10
1028 * Support for process record-replay and reverse debugging on aarch64*-linux*
1029 targets has been added. GDB now supports recording of A64 instruction set
1030 including advance SIMD instructions.
1032 * Support for Sun's version of the "stabs" debug file format has been removed.
1034 * GDB now honors the content of the file /proc/PID/coredump_filter
1035 (PID is the process ID) on GNU/Linux systems. This file can be used
1036 to specify the types of memory mappings that will be included in a
1037 corefile. For more information, please refer to the manual page of
1038 "core(5)". GDB also has a new command: "set use-coredump-filter
1039 on|off". It allows to set whether GDB will read the content of the
1040 /proc/PID/coredump_filter file when generating a corefile.
1042 * The "info os" command on GNU/Linux can now display information on
1044 "info os cpus" Listing of all cpus/cores on the system
1046 * GDB has two new commands: "set serial parity odd|even|none" and
1047 "show serial parity". These allows to set or show parity for the
1050 * The "info source" command now displays the producer string if it was
1051 present in the debug info. This typically includes the compiler version
1052 and may include things like its command line arguments.
1054 * The "info dll", an alias of the "info sharedlibrary" command,
1055 is now available on all platforms.
1057 * Directory names supplied to the "set sysroot" commands may be
1058 prefixed with "target:" to tell GDB to access shared libraries from
1059 the target system, be it local or remote. This replaces the prefix
1060 "remote:". The default sysroot has been changed from "" to
1061 "target:". "remote:" is automatically converted to "target:" for
1062 backward compatibility.
1064 * The system root specified by "set sysroot" will be prepended to the
1065 filename of the main executable (if reported to GDB as absolute by
1066 the operating system) when starting processes remotely, and when
1067 attaching to already-running local or remote processes.
1069 * GDB now supports automatic location and retrieval of executable
1070 files from remote targets. Remote debugging can now be initiated
1071 using only a "target remote" or "target extended-remote" command
1072 (no "set sysroot" or "file" commands are required). See "New remote
1075 * The "dump" command now supports verilog hex format.
1077 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1079 * On GNU/Linux, GDB and gdbserver are now able to access executable
1080 and shared library files without a "set sysroot" command when
1081 attaching to processes running in different mount namespaces from
1082 the debugger. This makes it possible to attach to processes in
1083 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1084 See "New remote packets" below.
1086 * The "tui reg" command now provides completion for all of the
1087 available register groups, including target specific groups.
1089 * The HISTSIZE environment variable is no longer read when determining
1090 the size of GDB's command history. GDB now instead reads the dedicated
1091 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1092 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1097 ** Memory ports can now be unbuffered.
1101 ** gdb.Objfile objects have a new attribute "username",
1102 which is the name of the objfile as specified by the user,
1103 without, for example, resolving symlinks.
1104 ** You can now write frame unwinders in Python.
1105 ** gdb.Type objects have a new method "optimized_out",
1106 returning optimized out gdb.Value instance of this type.
1107 ** gdb.Value objects have new methods "reference_value" and
1108 "const_value" which return a reference to the value and a
1109 "const" version of the value respectively.
1113 maint print symbol-cache
1114 Print the contents of the symbol cache.
1116 maint print symbol-cache-statistics
1117 Print statistics of symbol cache usage.
1119 maint flush-symbol-cache
1120 Flush the contents of the symbol cache.
1124 Start branch trace recording using Branch Trace Store (BTS) format.
1127 Evaluate expression by using the compiler and print result.
1131 Explicit commands for enabling and disabling tui mode.
1134 set mpx bound on i386 and amd64
1135 Support for bound table investigation on Intel MPX enabled applications.
1139 Start branch trace recording using Intel Processor Trace format.
1142 Print information about branch tracing internals.
1144 maint btrace packet-history
1145 Print the raw branch tracing data.
1147 maint btrace clear-packet-history
1148 Discard the stored raw branch tracing data.
1151 Discard all branch tracing data. It will be fetched and processed
1152 anew by the next "record" command.
1157 Renamed from "set debug dwarf2-die".
1158 show debug dwarf-die
1159 Renamed from "show debug dwarf2-die".
1161 set debug dwarf-read
1162 Renamed from "set debug dwarf2-read".
1163 show debug dwarf-read
1164 Renamed from "show debug dwarf2-read".
1166 maint set dwarf always-disassemble
1167 Renamed from "maint set dwarf2 always-disassemble".
1168 maint show dwarf always-disassemble
1169 Renamed from "maint show dwarf2 always-disassemble".
1171 maint set dwarf max-cache-age
1172 Renamed from "maint set dwarf2 max-cache-age".
1173 maint show dwarf max-cache-age
1174 Renamed from "maint show dwarf2 max-cache-age".
1176 set debug dwarf-line
1177 show debug dwarf-line
1178 Control display of debugging info regarding DWARF line processing.
1181 show max-completions
1182 Set the maximum number of candidates to be considered during
1183 completion. The default value is 200. This limit allows GDB
1184 to avoid generating large completion lists, the computation of
1185 which can cause the debugger to become temporarily unresponsive.
1187 set history remove-duplicates
1188 show history remove-duplicates
1189 Control the removal of duplicate history entries.
1191 maint set symbol-cache-size
1192 maint show symbol-cache-size
1193 Control the size of the symbol cache.
1195 set|show record btrace bts buffer-size
1196 Set and show the size of the ring buffer used for branch tracing in
1198 The obtained size may differ from the requested size. Use "info
1199 record" to see the obtained buffer size.
1201 set debug linux-namespaces
1202 show debug linux-namespaces
1203 Control display of debugging info regarding Linux namespaces.
1205 set|show record btrace pt buffer-size
1206 Set and show the size of the ring buffer used for branch tracing in
1207 Intel Processor Trace format.
1208 The obtained size may differ from the requested size. Use "info
1209 record" to see the obtained buffer size.
1211 maint set|show btrace pt skip-pad
1212 Set and show whether PAD packets are skipped when computing the
1215 * The command 'thread apply all' can now support new option '-ascending'
1216 to call its specified command for all threads in ascending order.
1218 * Python/Guile scripting
1220 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1221 special section named `.debug_gdb_scripts'.
1223 * New remote packets
1225 qXfer:btrace-conf:read
1226 Return the branch trace configuration for the current thread.
1228 Qbtrace-conf:bts:size
1229 Set the requested ring buffer size for branch tracing in BTS format.
1232 Enable Intel Procesor Trace-based branch tracing for the current
1233 process. The remote stub reports support for this packet to GDB's
1236 Qbtrace-conf:pt:size
1237 Set the requested ring buffer size for branch tracing in Intel Processor
1241 Indicates a memory breakpoint instruction was executed, irrespective
1242 of whether it was GDB that planted the breakpoint or the breakpoint
1243 is hardcoded in the program. This is required for correct non-stop
1247 Indicates the target stopped for a hardware breakpoint. This is
1248 required for correct non-stop mode operation.
1251 Return information about files on the remote system.
1253 qXfer:exec-file:read
1254 Return the full absolute name of the file that was executed to
1255 create a process running on the remote system.
1258 Select the filesystem on which vFile: operations with filename
1259 arguments will operate. This is required for GDB to be able to
1260 access files on remote targets where the remote stub does not
1261 share a common filesystem with the inferior(s).
1264 Indicates that a fork system call was executed.
1267 Indicates that a vfork system call was executed.
1269 vforkdone stop reason
1270 Indicates that a vfork child of the specified process has executed
1271 an exec or exit, allowing the vfork parent to resume execution.
1273 fork-events and vfork-events features in qSupported
1274 The qSupported packet allows GDB to request support for fork and
1275 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1276 and the qSupported response can contain the corresponding
1277 'stubfeatures'. Set and show commands can be used to display
1278 whether these features are enabled.
1280 * Extended-remote fork events
1282 ** GDB now has support for fork events on extended-remote Linux
1283 targets. For targets with Linux kernels 2.5.60 and later, this
1284 enables follow-fork-mode and detach-on-fork for both fork and
1285 vfork, as well as fork and vfork catchpoints.
1287 * The info record command now shows the recording format and the
1288 branch tracing configuration for the current thread when using
1289 the btrace record target.
1290 For the BTS format, it shows the ring buffer size.
1292 * GDB now has support for DTrace USDT (Userland Static Defined
1293 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1295 * GDB now supports access to vector registers on S/390 GNU/Linux
1298 * Removed command line options
1300 -xdb HP-UX XDB compatibility mode.
1302 * Removed targets and native configurations
1304 HP/PA running HP-UX hppa*-*-hpux*
1305 Itanium running HP-UX ia64-*-hpux*
1307 * New configure options
1310 This configure option allows the user to build GDB with support for
1311 Intel Processor Trace (default: auto). This requires libipt.
1313 --with-libipt-prefix=PATH
1314 Specify the path to the version of libipt that GDB should use.
1315 $PATH/include should contain the intel-pt.h header and
1316 $PATH/lib should contain the libipt.so library.
1318 *** Changes in GDB 7.9.1
1322 ** Xmethods can now specify a result type.
1324 *** Changes in GDB 7.9
1326 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1330 ** You can now access frame registers from Python scripts.
1331 ** New attribute 'producer' for gdb.Symtab objects.
1332 ** gdb.Objfile objects have a new attribute "progspace",
1333 which is the gdb.Progspace object of the containing program space.
1334 ** gdb.Objfile objects have a new attribute "owner".
1335 ** gdb.Objfile objects have a new attribute "build_id",
1336 which is the build ID generated when the file was built.
1337 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1338 ** A new event "gdb.clear_objfiles" has been added, triggered when
1339 selecting a new file to debug.
1340 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1341 ** New function gdb.lookup_objfile.
1343 New events which are triggered when GDB modifies the state of the
1346 ** gdb.events.inferior_call_pre: Function call is about to be made.
1347 ** gdb.events.inferior_call_post: Function call has just been made.
1348 ** gdb.events.memory_changed: A memory location has been altered.
1349 ** gdb.events.register_changed: A register has been altered.
1351 * New Python-based convenience functions:
1353 ** $_caller_is(name [, number_of_frames])
1354 ** $_caller_matches(regexp [, number_of_frames])
1355 ** $_any_caller_is(name [, number_of_frames])
1356 ** $_any_caller_matches(regexp [, number_of_frames])
1358 * GDB now supports the compilation and injection of source code into
1359 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1360 to compile the source code to object code, and if successful, inject
1361 and execute that code within the current context of the inferior.
1362 Currently the C language is supported. The commands used to
1363 interface with this new feature are:
1365 compile code [-raw|-r] [--] [source code]
1366 compile file [-raw|-r] filename
1370 demangle [-l language] [--] name
1371 Demangle "name" in the specified language, or the current language
1372 if elided. This command is renamed from the "maint demangle" command.
1373 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1374 as "maint demangler-warning".
1376 queue-signal signal-name-or-number
1377 Queue a signal to be delivered to the thread when it is resumed.
1379 add-auto-load-scripts-directory directory
1380 Add entries to the list of directories from which to load auto-loaded
1383 maint print user-registers
1384 List all currently available "user" registers.
1386 compile code [-r|-raw] [--] [source code]
1387 Compile, inject, and execute in the inferior the executable object
1388 code produced by compiling the provided source code.
1390 compile file [-r|-raw] filename
1391 Compile and inject into the inferior the executable object code
1392 produced by compiling the source code stored in the filename
1395 * On resume, GDB now always passes the signal the program had stopped
1396 for to the thread the signal was sent to, even if the user changed
1397 threads before resuming. Previously GDB would often (but not
1398 always) deliver the signal to the thread that happens to be current
1401 * Conversely, the "signal" command now consistently delivers the
1402 requested signal to the current thread. GDB now asks for
1403 confirmation if the program had stopped for a signal and the user
1404 switched threads meanwhile.
1406 * "breakpoint always-inserted" modes "off" and "auto" merged.
1408 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1409 won't remove breakpoints from the target until all threads stop,
1410 even in non-stop mode. The "auto" mode has been removed, and "off"
1411 is now the default mode.
1415 set debug symbol-lookup
1416 show debug symbol-lookup
1417 Control display of debugging info regarding symbol lookup.
1421 ** The -list-thread-groups command outputs an exit-code field for
1422 inferiors that have exited.
1426 MIPS SDE mips*-sde*-elf*
1430 Support for these obsolete configurations has been removed.
1432 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1433 SGI Irix-5.x mips-*-irix5*
1434 SGI Irix-6.x mips-*-irix6*
1435 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1436 VAX running Ultrix vax-*-ultrix*
1438 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1439 and "assf"), have been removed. Use the "sharedlibrary" command, or
1440 its alias "share", instead.
1442 *** Changes in GDB 7.8
1444 * New command line options
1447 This is an alias for the --data-directory option.
1449 * GDB supports printing and modifying of variable length automatic arrays
1450 as specified in ISO C99.
1452 * The ARM simulator now supports instruction level tracing
1453 with or without disassembly.
1457 GDB now has support for scripting using Guile. Whether this is
1458 available is determined at configure time.
1459 Guile version 2.0 or greater is required.
1460 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1462 * New commands (for set/show, see "New options" below)
1466 Invoke CODE by passing it to the Guile interpreter.
1470 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1472 info auto-load guile-scripts [regexp]
1473 Print the list of automatically loaded Guile scripts.
1475 * The source command is now capable of sourcing Guile scripts.
1476 This feature is dependent on the debugger being built with Guile support.
1480 set print symbol-loading (off|brief|full)
1481 show print symbol-loading
1482 Control whether to print informational messages when loading symbol
1483 information for a file. The default is "full", but when debugging
1484 programs with large numbers of shared libraries the amount of output
1485 becomes less useful.
1487 set guile print-stack (none|message|full)
1488 show guile print-stack
1489 Show a stack trace when an error is encountered in a Guile script.
1491 set auto-load guile-scripts (on|off)
1492 show auto-load guile-scripts
1493 Control auto-loading of Guile script files.
1495 maint ada set ignore-descriptive-types (on|off)
1496 maint ada show ignore-descriptive-types
1497 Control whether the debugger should ignore descriptive types in Ada
1498 programs. The default is not to ignore the descriptive types. See
1499 the user manual for more details on descriptive types and the intended
1500 usage of this option.
1502 set auto-connect-native-target
1504 Control whether GDB is allowed to automatically connect to the
1505 native target for the run, attach, etc. commands when not connected
1506 to any target yet. See also "target native" below.
1508 set record btrace replay-memory-access (read-only|read-write)
1509 show record btrace replay-memory-access
1510 Control what memory accesses are allowed during replay.
1512 maint set target-async (on|off)
1513 maint show target-async
1514 This controls whether GDB targets operate in synchronous or
1515 asynchronous mode. Normally the default is asynchronous, if it is
1516 available; but this can be changed to more easily debug problems
1517 occurring only in synchronous mode.
1519 set mi-async (on|off)
1521 Control whether MI asynchronous mode is preferred. This supersedes
1522 "set target-async" of previous GDB versions.
1524 * "set target-async" is deprecated as a CLI option and is now an alias
1525 for "set mi-async" (only puts MI into async mode).
1527 * Background execution commands (e.g., "c&", "s&", etc.) are now
1528 possible ``out of the box'' if the target supports them. Previously
1529 the user would need to explicitly enable the possibility with the
1530 "set target-async on" command.
1532 * New features in the GDB remote stub, GDBserver
1534 ** New option --debug-format=option1[,option2,...] allows one to add
1535 additional text to each output. At present only timestamps
1536 are supported: --debug-format=timestamps.
1537 Timestamps can also be turned on with the
1538 "monitor set debug-format timestamps" command from GDB.
1540 * The 'record instruction-history' command now starts counting instructions
1541 at one. This also affects the instruction ranges reported by the
1542 'record function-call-history' command when given the /i modifier.
1544 * The command 'record function-call-history' supports a new modifier '/c' to
1545 indent the function names based on their call stack depth.
1546 The fields for the '/i' and '/l' modifier have been reordered.
1547 The source line range is now prefixed with 'at'.
1548 The instruction range is now prefixed with 'inst'.
1549 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1550 "record instruction-history" and "list" commands.
1552 * The ranges given as arguments to the 'record function-call-history' and
1553 'record instruction-history' commands are now inclusive.
1555 * The btrace record target now supports the 'record goto' command.
1556 For locations inside the execution trace, the back trace is computed
1557 based on the information stored in the execution trace.
1559 * The btrace record target supports limited reverse execution and replay.
1560 The target does not record data and therefore does not allow reading
1561 memory or registers.
1563 * The "catch syscall" command now works on s390*-linux* targets.
1565 * The "compare-sections" command is no longer specific to target
1566 remote. It now works with all targets.
1568 * All native targets are now consistently called "native".
1569 Consequently, the "target child", "target GNU", "target djgpp",
1570 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1571 commands have been replaced with "target native". The QNX/NTO port
1572 leaves the "procfs" target in place and adds a "native" target for
1573 consistency with other ports. The impact on users should be minimal
1574 as these commands previously either throwed an error, or were
1575 no-ops. The target's name is visible in the output of the following
1576 commands: "help target", "info target", "info files", "maint print
1579 * The "target native" command now connects to the native target. This
1580 can be used to launch native programs even when "set
1581 auto-connect-native-target" is set to off.
1583 * GDB now supports access to Intel MPX registers on GNU/Linux.
1585 * Support for Intel AVX-512 registers on GNU/Linux.
1586 Support displaying and modifying Intel AVX-512 registers
1587 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1589 * New remote packets
1591 qXfer:btrace:read's annex
1592 The qXfer:btrace:read packet supports a new annex 'delta' to read
1593 branch trace incrementally.
1597 ** Valid Python operations on gdb.Value objects representing
1598 structs/classes invoke the corresponding overloaded operators if
1600 ** New `Xmethods' feature in the Python API. Xmethods are
1601 additional methods or replacements for existing methods of a C++
1602 class. This feature is useful for those cases where a method
1603 defined in C++ source code could be inlined or optimized out by
1604 the compiler, making it unavailable to GDB.
1607 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1609 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1610 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1611 its alias "share", instead.
1613 * The commands "set remotebaud" and "show remotebaud" are no longer
1614 supported. Use "set serial baud" and "show serial baud" (respectively)
1619 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1620 target-async". The latter is left as a deprecated alias of the
1621 former for backward compatibility. If the target supports it,
1622 CLI background execution commands are now always possible by
1623 default, independently of whether the frontend stated a
1624 preference for asynchronous execution with "-gdb-set mi-async".
1625 Previously "-gdb-set target-async off" affected both MI execution
1626 commands and CLI execution commands.
1628 *** Changes in GDB 7.7
1630 * Improved support for process record-replay and reverse debugging on
1631 arm*-linux* targets. Support for thumb32 and syscall instruction
1632 recording has been added.
1634 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1636 * GDB now supports Fission DWP file format version 2.
1637 http://gcc.gnu.org/wiki/DebugFission
1639 * New convenience function "$_isvoid", to check whether an expression
1640 is void. A void expression is an expression where the type of the
1641 result is "void". For example, some convenience variables may be
1642 "void" when evaluated (e.g., "$_exitcode" before the execution of
1643 the program being debugged; or an undefined convenience variable).
1644 Another example, when calling a function whose return type is
1647 * The "maintenance print objfiles" command now takes an optional regexp.
1649 * The "catch syscall" command now works on arm*-linux* targets.
1651 * GDB now consistently shows "<not saved>" when printing values of
1652 registers the debug info indicates have not been saved in the frame
1653 and there's nowhere to retrieve them from
1654 (callee-saved/call-clobbered registers):
1659 (gdb) info registers rax
1662 Before, the former would print "<optimized out>", and the latter
1663 "*value not available*".
1665 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1670 ** Frame filters and frame decorators have been added.
1671 ** Temporary breakpoints are now supported.
1672 ** Line tables representation has been added.
1673 ** New attribute 'parent_type' for gdb.Field objects.
1674 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1675 ** New attribute 'name' for gdb.Type objects.
1679 Nios II ELF nios2*-*-elf
1680 Nios II GNU/Linux nios2*-*-linux
1681 Texas Instruments MSP430 msp430*-*-elf
1683 * Removed native configurations
1685 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1686 been removed. ELF variants of these configurations are kept supported.
1688 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1689 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1690 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1691 i[34567]86-*-openbsd3.[0-3]
1692 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1693 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1694 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1698 Like "catch throw", but catches a re-thrown exception.
1699 maint check-psymtabs
1700 Renamed from old "maint check-symtabs".
1702 Perform consistency checks on symtabs.
1703 maint expand-symtabs
1704 Expand symtabs matching an optional regexp.
1707 Display the details of GDB configure-time options.
1709 maint set|show per-command
1710 maint set|show per-command space
1711 maint set|show per-command time
1712 maint set|show per-command symtab
1713 Enable display of per-command gdb resource usage.
1715 remove-symbol-file FILENAME
1716 remove-symbol-file -a ADDRESS
1717 Remove a symbol file added via add-symbol-file. The file to remove
1718 can be identified by its filename or by an address that lies within
1719 the boundaries of this symbol file in memory.
1722 info exceptions REGEXP
1723 Display the list of Ada exceptions defined in the program being
1724 debugged. If provided, only the exceptions whose names match REGEXP
1729 set debug symfile off|on
1731 Control display of debugging info regarding reading symbol files and
1732 symbol tables within those files
1734 set print raw frame-arguments
1735 show print raw frame-arguments
1736 Set/show whether to print frame arguments in raw mode,
1737 disregarding any defined pretty-printers.
1739 set remote trace-status-packet
1740 show remote trace-status-packet
1741 Set/show the use of remote protocol qTStatus packet.
1745 Control display of debugging messages related to Nios II targets.
1749 Control whether target-assisted range stepping is enabled.
1751 set startup-with-shell
1752 show startup-with-shell
1753 Specifies whether Unix child processes are started via a shell or
1758 Use the target memory cache for accesses to the code segment. This
1759 improves performance of remote debugging (particularly disassembly).
1761 * You can now use a literal value 'unlimited' for options that
1762 interpret 0 or -1 as meaning "unlimited". E.g., "set
1763 trace-buffer-size unlimited" is now an alias for "set
1764 trace-buffer-size -1" and "set height unlimited" is now an alias for
1767 * The "set debug symtab-create" debugging option of GDB has been changed to
1768 accept a verbosity level. 0 means "off", 1 provides basic debugging
1769 output, and values of 2 or greater provides more verbose output.
1771 * New command-line options
1773 Display the details of GDB configure-time options.
1775 * The command 'tsave' can now support new option '-ctf' to save trace
1776 buffer in Common Trace Format.
1778 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1781 * GDB now implements the the C++ 'typeid' operator.
1783 * The new convenience variable $_exception holds the exception being
1784 thrown or caught at an exception-related catchpoint.
1786 * The exception-related catchpoints, like "catch throw", now accept a
1787 regular expression which can be used to filter exceptions by type.
1789 * The new convenience variable $_exitsignal is automatically set to
1790 the terminating signal number when the program being debugged dies
1791 due to an uncaught signal.
1795 ** All MI commands now accept an optional "--language" option.
1796 Support for this feature can be verified by using the "-list-features"
1797 command, which should contain "language-option".
1799 ** The new command -info-gdb-mi-command allows the user to determine
1800 whether a GDB/MI command is supported or not.
1802 ** The "^error" result record returned when trying to execute an undefined
1803 GDB/MI command now provides a variable named "code" whose content is the
1804 "undefined-command" error code. Support for this feature can be verified
1805 by using the "-list-features" command, which should contain
1806 "undefined-command-error-code".
1808 ** The -trace-save MI command can optionally save trace buffer in Common
1811 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1813 ** The command -data-list-register-values now accepts an optional
1814 "--skip-unavailable" option. When used, only the available registers
1817 ** The new command -trace-frame-collected dumps collected variables,
1818 computed expressions, tvars, memory and registers in a traceframe.
1820 ** The commands -stack-list-locals, -stack-list-arguments and
1821 -stack-list-variables now accept an option "--skip-unavailable".
1822 When used, only the available locals or arguments are displayed.
1824 ** The -exec-run command now accepts an optional "--start" option.
1825 When used, the command follows the same semantics as the "start"
1826 command, stopping the program's execution at the start of its
1827 main subprogram. Support for this feature can be verified using
1828 the "-list-features" command, which should contain
1829 "exec-run-start-option".
1831 ** The new commands -catch-assert and -catch-exceptions insert
1832 catchpoints stopping the program when Ada exceptions are raised.
1834 ** The new command -info-ada-exceptions provides the equivalent of
1835 the new "info exceptions" command.
1837 * New system-wide configuration scripts
1838 A GDB installation now provides scripts suitable for use as system-wide
1839 configuration scripts for the following systems:
1843 * GDB now supports target-assigned range stepping with remote targets.
1844 This improves the performance of stepping source lines by reducing
1845 the number of control packets from/to GDB. See "New remote packets"
1848 * GDB now understands the element 'tvar' in the XML traceframe info.
1849 It has the id of the collected trace state variables.
1851 * On S/390 targets that provide the transactional-execution feature,
1852 the program interruption transaction diagnostic block (TDB) is now
1853 represented as a number of additional "registers" in GDB.
1855 * New remote packets
1859 The vCont packet supports a new 'r' action, that tells the remote
1860 stub to step through an address range itself, without GDB
1861 involvemement at each single-step.
1863 qXfer:libraries-svr4:read's annex
1864 The previously unused annex of the qXfer:libraries-svr4:read packet
1865 is now used to support passing an argument list. The remote stub
1866 reports support for this argument list to GDB's qSupported query.
1867 The defined arguments are "start" and "prev", used to reduce work
1868 necessary for library list updating, resulting in significant
1871 * New features in the GDB remote stub, GDBserver
1873 ** GDBserver now supports target-assisted range stepping. Currently
1874 enabled on x86/x86_64 GNU/Linux targets.
1876 ** GDBserver now adds element 'tvar' in the XML in the reply to
1877 'qXfer:traceframe-info:read'. It has the id of the collected
1878 trace state variables.
1880 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1883 * New 'z' formatter for printing and examining memory, this displays the
1884 value as hexadecimal zero padded on the left to the size of the type.
1886 * GDB can now use Windows x64 unwinding data.
1888 * The "set remotebaud" command has been replaced by "set serial baud".
1889 Similarly, "show remotebaud" has been replaced by "show serial baud".
1890 The "set remotebaud" and "show remotebaud" commands are still available
1891 to provide backward compatibility with older versions of GDB.
1893 *** Changes in GDB 7.6
1895 * Target record has been renamed to record-full.
1896 Record/replay is now enabled with the "record full" command.
1897 This also affects settings that are associated with full record/replay
1898 that have been moved from "set/show record" to "set/show record full":
1900 set|show record full insn-number-max
1901 set|show record full stop-at-limit
1902 set|show record full memory-query
1904 * A new record target "record-btrace" has been added. The new target
1905 uses hardware support to record the control-flow of a process. It
1906 does not support replaying the execution, but it implements the
1907 below new commands for investigating the recorded execution log.
1908 This new recording method can be enabled using:
1912 The "record-btrace" target is only available on Intel Atom processors
1913 and requires a Linux kernel 2.6.32 or later.
1915 * Two new commands have been added for record/replay to give information
1916 about the recorded execution without having to replay the execution.
1917 The commands are only supported by "record btrace".
1919 record instruction-history prints the execution history at
1920 instruction granularity
1922 record function-call-history prints the execution history at
1923 function granularity
1925 * New native configurations
1927 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1928 FreeBSD/powerpc powerpc*-*-freebsd
1929 x86_64/Cygwin x86_64-*-cygwin*
1930 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1934 ARM AArch64 aarch64*-*-elf
1935 ARM AArch64 GNU/Linux aarch64*-*-linux
1936 Lynx 178 PowerPC powerpc-*-lynx*178
1937 x86_64/Cygwin x86_64-*-cygwin*
1938 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1940 * If the configured location of system.gdbinit file (as given by the
1941 --with-system-gdbinit option at configure time) is in the
1942 data-directory (as specified by --with-gdb-datadir at configure
1943 time) or in one of its subdirectories, then GDB will look for the
1944 system-wide init file in the directory specified by the
1945 --data-directory command-line option.
1947 * New command line options:
1949 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1950 other initialization files, unlike -nx which disables all of them.
1952 * Removed command line options
1954 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1957 * The 'ptype' and 'whatis' commands now accept an argument to control
1960 * 'info proc' now works on some core files.
1964 ** Vectors can be created with gdb.Type.vector.
1966 ** Python's atexit.register now works in GDB.
1968 ** Types can be pretty-printed via a Python API.
1970 ** Python 3 is now supported (in addition to Python 2.4 or later)
1972 ** New class gdb.Architecture exposes GDB's internal representation
1973 of architecture in the Python API.
1975 ** New method Frame.architecture returns the gdb.Architecture object
1976 corresponding to the frame's architecture.
1978 * New Python-based convenience functions:
1980 ** $_memeq(buf1, buf2, length)
1981 ** $_streq(str1, str2)
1983 ** $_regex(str, regex)
1985 * The 'cd' command now defaults to using '~' (the home directory) if not
1988 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1989 default for GCC since November 2000.
1991 * The command 'forward-search' can now be abbreviated as 'fo'.
1993 * The command 'info tracepoints' can now display 'installed on target'
1994 or 'not installed on target' for each non-pending location of tracepoint.
1996 * New configure options
1998 --enable-libmcheck/--disable-libmcheck
1999 By default, development versions are built with -lmcheck on hosts
2000 that support it, in order to help track memory corruption issues.
2001 Release versions, on the other hand, are built without -lmcheck
2002 by default. The --enable-libmcheck/--disable-libmcheck configure
2003 options allow the user to override that default.
2004 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2005 This configure option allows the user to build GDB with
2006 libbabeltrace using which GDB can read Common Trace Format data.
2008 * New commands (for set/show, see "New options" below)
2011 Catch signals. This is similar to "handle", but allows commands and
2012 conditions to be attached.
2015 List the BFDs known to GDB.
2017 python-interactive [command]
2019 Start a Python interactive prompt, or evaluate the optional command
2020 and print the result of expressions.
2023 "py" is a new alias for "python".
2025 enable type-printer [name]...
2026 disable type-printer [name]...
2027 Enable or disable type printers.
2031 ** For the Renesas Super-H architecture, the "regs" command has been removed
2032 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2037 set print type methods (on|off)
2038 show print type methods
2039 Control whether method declarations are displayed by "ptype".
2040 The default is to show them.
2042 set print type typedefs (on|off)
2043 show print type typedefs
2044 Control whether typedef definitions are displayed by "ptype".
2045 The default is to show them.
2047 set filename-display basename|relative|absolute
2048 show filename-display
2049 Control the way in which filenames is displayed.
2050 The default is "relative", which preserves previous behavior.
2052 set trace-buffer-size
2053 show trace-buffer-size
2054 Request target to change the size of trace buffer.
2056 set remote trace-buffer-size-packet auto|on|off
2057 show remote trace-buffer-size-packet
2058 Control the use of the remote protocol `QTBuffer:size' packet.
2062 Control display of debugging messages related to ARM AArch64.
2065 set debug coff-pe-read
2066 show debug coff-pe-read
2067 Control display of debugging messages related to reading of COFF/PE
2072 Control display of debugging messages related to Mach-O symbols
2075 set debug notification
2076 show debug notification
2077 Control display of debugging info for async remote notification.
2081 ** Command parameter changes are now notified using new async record
2082 "=cmd-param-changed".
2083 ** Trace frame changes caused by command "tfind" are now notified using
2084 new async record "=traceframe-changed".
2085 ** The creation, deletion and modification of trace state variables
2086 are now notified using new async records "=tsv-created",
2087 "=tsv-deleted" and "=tsv-modified".
2088 ** The start and stop of process record are now notified using new
2089 async record "=record-started" and "=record-stopped".
2090 ** Memory changes are now notified using new async record
2092 ** The data-disassemble command response will include a "fullname" field
2093 containing the absolute file name when source has been requested.
2094 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2095 command, to allow pattern filling of memory areas.
2096 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2097 library load/unload events.
2098 ** The response to breakpoint commands and breakpoint async records
2099 includes an "installed" field containing a boolean state about each
2100 non-pending tracepoint location is whether installed on target or not.
2101 ** Output of the "-trace-status" command includes a "trace-file" field
2102 containing the name of the trace file being examined. This field is
2103 optional, and only present when examining a trace file.
2104 ** The "fullname" field is now always present along with the "file" field,
2105 even if the file cannot be found by GDB.
2107 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2108 You must have the LZMA library available when configuring GDB for this
2109 feature to be enabled. For more information, see:
2110 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2112 * New remote packets
2115 Set the size of trace buffer. The remote stub reports support for this
2116 packet to gdb's qSupported query.
2119 Enable Branch Trace Store (BTS)-based branch tracing for the current
2120 thread. The remote stub reports support for this packet to gdb's
2124 Disable branch tracing for the current thread. The remote stub reports
2125 support for this packet to gdb's qSupported query.
2128 Read the traced branches for the current thread. The remote stub
2129 reports support for this packet to gdb's qSupported query.
2131 *** Changes in GDB 7.5
2133 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2134 for more x32 ABI info.
2136 * GDB now supports access to MIPS DSP registers on Linux targets.
2138 * GDB now supports debugging microMIPS binaries.
2140 * The "info os" command on GNU/Linux can now display information on
2141 several new classes of objects managed by the operating system:
2142 "info os procgroups" lists process groups
2143 "info os files" lists file descriptors
2144 "info os sockets" lists internet-domain sockets
2145 "info os shm" lists shared-memory regions
2146 "info os semaphores" lists semaphores
2147 "info os msg" lists message queues
2148 "info os modules" lists loaded kernel modules
2150 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2151 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2152 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2153 options and inspect the probe arguments using the new $_probe_arg family
2154 of convenience variables. You can obtain more information about SystemTap
2155 in <http://sourceware.org/systemtap/>.
2157 * GDB now supports reversible debugging on ARM, it allows you to
2158 debug basic ARM and THUMB instructions, and provides
2159 record/replay support.
2161 * The option "symbol-reloading" has been deleted as it is no longer used.
2165 ** GDB commands implemented in Python can now be put in command class
2168 ** The "maint set python print-stack on|off" is now deleted.
2170 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2171 apply "flag enum"-style pretty-printing to any enum.
2173 ** gdb.lookup_symbol can now work when there is no current frame.
2175 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2176 the source at which the symbol was defined.
2178 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2179 method 'value'. The former indicates whether the symbol needs a
2180 frame in order to compute its value, and the latter computes the
2183 ** A new method 'referenced_value' on gdb.Value objects which can
2184 dereference pointer as well as C++ reference values.
2186 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2187 which return the global and static blocks (as gdb.Block objects),
2188 of the underlying symbol table, respectively.
2190 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2191 object associated with a PC value.
2193 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2194 of the address range occupied by code for the current source line.
2196 * Go language support.
2197 GDB now supports debugging programs written in the Go programming
2200 * GDBserver now supports stdio connections.
2201 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2203 * The binary "gdbtui" can no longer be built or installed.
2204 Use "gdb -tui" instead.
2206 * GDB will now print "flag" enums specially. A flag enum is one where
2207 all the enumerator values have no bits in common when pairwise
2208 "and"ed. When printing a value whose type is a flag enum, GDB will
2209 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2210 (gdb) print (enum E) 3
2213 * The filename part of a linespec will now match trailing components
2214 of a source file name. For example, "break gcc/expr.c:1000" will
2215 now set a breakpoint in build/gcc/expr.c, but not
2216 build/libcpp/expr.c.
2218 * The "info proc" and "generate-core-file" commands will now also
2219 work on remote targets connected to GDBserver on Linux.
2221 * The command "info catch" has been removed. It has been disabled
2222 since December 2007.
2224 * The "catch exception" and "catch assert" commands now accept
2225 a condition at the end of the command, much like the "break"
2226 command does. For instance:
2228 (gdb) catch exception Constraint_Error if Barrier = True
2230 Previously, it was possible to add a condition to such catchpoints,
2231 but it had to be done as a second step, after the catchpoint had been
2232 created, using the "condition" command.
2234 * The "info static-tracepoint-marker" command will now also work on
2235 native Linux targets with in-process agent.
2237 * GDB can now set breakpoints on inlined functions.
2239 * The .gdb_index section has been updated to include symbols for
2240 inlined functions. GDB will ignore older .gdb_index sections by
2241 default, which could cause symbol files to be loaded more slowly
2242 until their .gdb_index sections can be recreated. The new command
2243 "set use-deprecated-index-sections on" will cause GDB to use any older
2244 .gdb_index sections it finds. This will restore performance, but the
2245 ability to set breakpoints on inlined functions will be lost in symbol
2246 files with older .gdb_index sections.
2248 The .gdb_index section has also been updated to record more information
2249 about each symbol. This speeds up the "info variables", "info functions"
2250 and "info types" commands when used with programs having the .gdb_index
2251 section, as well as speeding up debugging with shared libraries using
2252 the .gdb_index section.
2254 * Ada support for GDB/MI Variable Objects has been added.
2256 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2261 ** New command -info-os is the MI equivalent of "info os".
2263 ** Output logs ("set logging" and related) now include MI output.
2267 ** "set use-deprecated-index-sections on|off"
2268 "show use-deprecated-index-sections on|off"
2269 Controls the use of deprecated .gdb_index sections.
2271 ** "catch load" and "catch unload" can be used to stop when a shared
2272 library is loaded or unloaded, respectively.
2274 ** "enable count" can be used to auto-disable a breakpoint after
2277 ** "info vtbl" can be used to show the virtual method tables for
2278 C++ and Java objects.
2280 ** "explore" and its sub commands "explore value" and "explore type"
2281 can be used to recursively explore values and types of
2282 expressions. These commands are available only if GDB is
2283 configured with '--with-python'.
2285 ** "info auto-load" shows status of all kinds of auto-loaded files,
2286 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2287 sequences of commands files, "info auto-load python-scripts"
2288 shows status of auto-loading Python script files,
2289 "info auto-load local-gdbinit" shows status of loading init file
2290 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2291 status of inferior specific thread debugging shared library loading.
2293 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2294 and "show auto-load-scripts" commands have been deprecated, use their
2295 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2296 and "show auto-load python-scripts" counterparts instead.
2298 ** "dprintf location,format,args..." creates a dynamic printf, which
2299 is basically a breakpoint that does a printf and immediately
2300 resumes your program's execution, so it is like a printf that you
2301 can insert dynamically at runtime instead of at compiletime.
2303 ** "set print symbol"
2305 Controls whether GDB attempts to display the symbol, if any,
2306 corresponding to addresses it prints. This defaults to "on", but
2307 you can set it to "off" to restore GDB's previous behavior.
2309 * Deprecated commands
2311 ** For the Renesas Super-H architecture, the "regs" command has been
2312 deprecated, and "info all-registers" should be used instead.
2316 Renesas RL78 rl78-*-elf
2317 HP OpenVMS ia64 ia64-hp-openvms*
2319 * GDBserver supports evaluation of breakpoint conditions. When
2320 support is advertised by GDBserver, GDB may be told to send the
2321 breakpoint conditions in bytecode form to GDBserver. GDBserver
2322 will only report the breakpoint trigger to GDB when its condition
2327 set mips compression
2328 show mips compression
2329 Select the compressed ISA encoding used in functions that have no symbol
2330 information available. The encoding can be set to either of:
2333 and is updated automatically from ELF file flags if available.
2335 set breakpoint condition-evaluation
2336 show breakpoint condition-evaluation
2337 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2338 GDBserver ("target"). Default option "auto" chooses the most efficient
2340 This option can improve debugger efficiency depending on the speed of the
2344 Disable auto-loading globally.
2347 Show auto-loading setting of all kinds of auto-loaded files.
2349 set auto-load gdb-scripts on|off
2350 show auto-load gdb-scripts
2351 Control auto-loading of GDB canned sequences of commands files.
2353 set auto-load python-scripts on|off
2354 show auto-load python-scripts
2355 Control auto-loading of Python script files.
2357 set auto-load local-gdbinit on|off
2358 show auto-load local-gdbinit
2359 Control loading of init file (.gdbinit) from current directory.
2361 set auto-load libthread-db on|off
2362 show auto-load libthread-db
2363 Control auto-loading of inferior specific thread debugging shared library.
2365 set auto-load scripts-directory <dir1>[:<dir2>...]
2366 show auto-load scripts-directory
2367 Set a list of directories from which to load auto-loaded scripts.
2368 Automatically loaded Python scripts and GDB scripts are located in one
2369 of the directories listed by this option.
2370 The delimiter (':' above) may differ according to the host platform.
2372 set auto-load safe-path <dir1>[:<dir2>...]
2373 show auto-load safe-path
2374 Set a list of directories from which it is safe to auto-load files.
2375 The delimiter (':' above) may differ according to the host platform.
2377 set debug auto-load on|off
2378 show debug auto-load
2379 Control display of debugging info for auto-loading the files above.
2381 set dprintf-style gdb|call|agent
2383 Control the way in which a dynamic printf is performed; "gdb"
2384 requests a GDB printf command, while "call" causes dprintf to call a
2385 function in the inferior. "agent" requests that the target agent
2386 (such as GDBserver) do the printing.
2388 set dprintf-function <expr>
2389 show dprintf-function
2390 set dprintf-channel <expr>
2391 show dprintf-channel
2392 Set the function and optional first argument to the call when using
2393 the "call" style of dynamic printf.
2395 set disconnected-dprintf on|off
2396 show disconnected-dprintf
2397 Control whether agent-style dynamic printfs continue to be in effect
2398 after GDB disconnects.
2400 * New configure options
2402 --with-auto-load-dir
2403 Configure default value for the 'set auto-load scripts-directory'
2404 setting above. It defaults to '$debugdir:$datadir/auto-load',
2405 $debugdir representing global debugging info directories (available
2406 via 'show debug-file-directory') and $datadir representing GDB's data
2407 directory (available via 'show data-directory').
2409 --with-auto-load-safe-path
2410 Configure default value for the 'set auto-load safe-path' setting
2411 above. It defaults to the --with-auto-load-dir setting.
2413 --without-auto-load-safe-path
2414 Set 'set auto-load safe-path' to '/', effectively disabling this
2417 * New remote packets
2419 z0/z1 conditional breakpoints extension
2421 The z0/z1 breakpoint insertion packets have been extended to carry
2422 a list of conditional expressions over to the remote stub depending on the
2423 condition evaluation mode. The use of this extension can be controlled
2424 via the "set remote conditional-breakpoints-packet" command.
2428 Specify the signals which the remote stub may pass to the debugged
2429 program without GDB involvement.
2431 * New command line options
2433 --init-command=FILE, -ix Like --command, -x but execute it
2434 before loading inferior.
2435 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2436 execute it before loading inferior.
2438 *** Changes in GDB 7.4
2440 * GDB now handles ambiguous linespecs more consistently; the existing
2441 FILE:LINE support has been expanded to other types of linespecs. A
2442 breakpoint will now be set on all matching locations in all
2443 inferiors, and locations will be added or removed according to
2446 * GDB now allows you to skip uninteresting functions and files when
2447 stepping with the "skip function" and "skip file" commands.
2449 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2450 and "show remote hardware-watchpoint-length-limit". These allows to
2451 set or show the maximum length limit (in bytes) of a remote
2452 target hardware watchpoint.
2454 This allows e.g. to use "unlimited" hardware watchpoints with the
2455 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2456 watchpoints are slower than real hardware watchpoints but are
2457 significantly faster than gdb software watchpoints.
2461 ** The register_pretty_printer function in module gdb.printing now takes
2462 an optional `replace' argument. If True, the new printer replaces any
2465 ** The "maint set python print-stack on|off" command has been
2466 deprecated and will be deleted in GDB 7.5.
2467 A new command: "set python print-stack none|full|message" has
2468 replaced it. Additionally, the default for "print-stack" is
2469 now "message", which just prints the error message without
2472 ** A prompt substitution hook (prompt_hook) is now available to the
2475 ** A new Python module, gdb.prompt has been added to the GDB Python
2476 modules library. This module provides functionality for
2477 escape sequences in prompts (used by set/show
2478 extended-prompt). These escape sequences are replaced by their
2479 corresponding value.
2481 ** Python commands and convenience-functions located in
2482 'data-directory'/python/gdb/command and
2483 'data-directory'/python/gdb/function are now automatically loaded
2486 ** Blocks now provide four new attributes. global_block and
2487 static_block will return the global and static blocks
2488 respectively. is_static and is_global are boolean attributes
2489 that indicate if the block is one of those two types.
2491 ** Symbols now provide the "type" attribute, the type of the symbol.
2493 ** The "gdb.breakpoint" function has been deprecated in favor of
2496 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2497 of a function. This class is based on the "finish" command
2498 available in the CLI.
2500 ** Type objects for struct and union types now allow access to
2501 the fields using standard Python dictionary (mapping) methods.
2502 For example, "some_type['myfield']" now works, as does
2503 "some_type.items()".
2505 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2508 ** A new function, "deep_items" has been added to the gdb.types
2509 module in the GDB Python modules library. This function returns
2510 an iterator over the fields of a struct or union type. Unlike
2511 the standard Python "iteritems" method, it will recursively traverse
2512 any anonymous fields.
2516 ** "*stopped" events can report several new "reason"s, such as
2519 ** Breakpoint changes are now notified using new async records, like
2520 "=breakpoint-modified".
2522 ** New command -ada-task-info.
2524 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2525 $sdir specifies the default system locations of shared libraries.
2526 $pdir specifies the directory where the libpthread used by the application
2529 GDB no longer looks in $sdir and $pdir after it has searched the directories
2530 mentioned in libthread-db-search-path. If you want to search those
2531 directories, they must be specified in libthread-db-search-path.
2532 The default value of libthread-db-search-path on GNU/Linux and Solaris
2533 systems is now "$sdir:$pdir".
2535 $pdir is not supported by gdbserver, it is currently ignored.
2536 $sdir is supported by gdbserver.
2538 * New configure option --with-iconv-bin.
2539 When using the internationalization support like the one in the GNU C
2540 library, GDB will invoke the "iconv" program to get a list of supported
2541 character sets. If this program lives in a non-standard location, one can
2542 use this option to specify where to find it.
2544 * When natively debugging programs on PowerPC BookE processors running
2545 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2546 watchpoints, which specify a mask in addition to an address to watch.
2547 The mask specifies that some bits of an address (the bits which are
2548 reset in the mask) should be ignored when matching the address accessed
2549 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2550 section in the user manual for more details.
2552 * The new option --once causes GDBserver to stop listening for connections once
2553 the first connection is made. The listening port used by GDBserver will
2554 become available after that.
2556 * New commands "info macros" and "alias" have been added.
2558 * New function parameters suffix @entry specifies value of function parameter
2559 at the time the function got called. Entry values are available only since
2565 "!" is now an alias of the "shell" command.
2566 Note that no space is needed between "!" and SHELL COMMAND.
2570 watch EXPRESSION mask MASK_VALUE
2571 The watch command now supports the mask argument which allows creation
2572 of masked watchpoints, if the current architecture supports this feature.
2574 info auto-load-scripts [REGEXP]
2575 This command was formerly named "maintenance print section-scripts".
2576 It is now generally useful and is no longer a maintenance-only command.
2578 info macro [-all] [--] MACRO
2579 The info macro command has new options `-all' and `--'. The first for
2580 printing all definitions of a macro. The second for explicitly specifying
2581 the end of arguments and the beginning of the macro name in case the macro
2582 name starts with a hyphen.
2584 collect[/s] EXPRESSIONS
2585 The tracepoint collect command now takes an optional modifier "/s"
2586 that directs it to dereference pointer-to-character types and
2587 collect the bytes of memory up to a zero byte. The behavior is
2588 similar to what you see when you use the regular print command on a
2589 string. An optional integer following the "/s" sets a bound on the
2590 number of bytes that will be collected.
2593 The trace start command now interprets any supplied arguments as a
2594 note to be recorded with the trace run, with an effect similar to
2595 setting the variable trace-notes.
2598 The trace stop command now interprets any arguments as a note to be
2599 mentioned along with the tstatus report that the trace was stopped
2600 with a command. The effect is similar to setting the variable
2603 * Tracepoints can now be enabled and disabled at any time after a trace
2604 experiment has been started using the standard "enable" and "disable"
2605 commands. It is now possible to start a trace experiment with no enabled
2606 tracepoints; GDB will display a warning, but will allow the experiment to
2607 begin, assuming that tracepoints will be enabled as needed while the trace
2610 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2611 locations with 4-byte instructions, when they were previously
2612 limited to locations with instructions of 5 bytes or longer.
2616 set debug dwarf2-read
2617 show debug dwarf2-read
2618 Turns on or off display of debugging messages related to reading
2619 DWARF debug info. The default is off.
2621 set debug symtab-create
2622 show debug symtab-create
2623 Turns on or off display of debugging messages related to symbol table
2624 creation. The default is off.
2627 show extended-prompt
2628 Set the GDB prompt, and allow escape sequences to be inserted to
2629 display miscellaneous information (see 'help set extended-prompt'
2630 for the list of sequences). This prompt (and any information
2631 accessed through the escape sequences) is updated every time the
2632 prompt is displayed.
2634 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2635 show print entry-values
2636 Set printing of frame argument values at function entry. In some cases
2637 GDB can determine the value of function argument which was passed by the
2638 function caller, even if the value was modified inside the called function.
2640 set debug entry-values
2641 show debug entry-values
2642 Control display of debugging info for determining frame argument values at
2643 function entry and virtual tail call frames.
2645 set basenames-may-differ
2646 show basenames-may-differ
2647 Set whether a source file may have multiple base names.
2648 (A "base name" is the name of a file with the directory part removed.
2649 Example: The base name of "/home/user/hello.c" is "hello.c".)
2650 If set, GDB will canonicalize file names (e.g., expand symlinks)
2651 before comparing them. Canonicalization is an expensive operation,
2652 but it allows the same file be known by more than one base name.
2653 If not set (the default), all source files are assumed to have just
2654 one base name, and gdb will do file name comparisons more efficiently.
2660 Set a user name and notes for the current and any future trace runs.
2661 This is useful for long-running and/or disconnected traces, to
2662 inform others (or yourself) as to who is running the trace, supply
2663 contact information, or otherwise explain what is going on.
2665 set trace-stop-notes
2666 show trace-stop-notes
2667 Set a note attached to the trace run, that is displayed when the
2668 trace has been stopped by a tstop command. This is useful for
2669 instance as an explanation, if you are stopping a trace run that was
2670 started by someone else.
2672 * New remote packets
2676 Dynamically enable a tracepoint in a started trace experiment.
2680 Dynamically disable a tracepoint in a started trace experiment.
2684 Set the user and notes of the trace run.
2688 Query the current status of a tracepoint.
2692 Query the minimum length of instruction at which a fast tracepoint may
2695 * Dcache size (number of lines) and line-size are now runtime-configurable
2696 via "set dcache line" and "set dcache line-size" commands.
2700 Texas Instruments TMS320C6x tic6x-*-*
2704 Renesas RL78 rl78-*-elf
2706 *** Changes in GDB 7.3.1
2708 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2710 *** Changes in GDB 7.3
2712 * GDB has a new command: "thread find [REGEXP]".
2713 It finds the thread id whose name, target id, or thread extra info
2714 matches the given regular expression.
2716 * The "catch syscall" command now works on mips*-linux* targets.
2718 * The -data-disassemble MI command now supports modes 2 and 3 for
2719 dumping the instruction opcodes.
2721 * New command line options
2723 -data-directory DIR Specify DIR as the "data-directory".
2724 This is mostly for testing purposes.
2726 * The "maint set python auto-load on|off" command has been renamed to
2727 "set auto-load-scripts on|off".
2729 * GDB has a new command: "set directories".
2730 It is like the "dir" command except that it replaces the
2731 source path list instead of augmenting it.
2733 * GDB now understands thread names.
2735 On GNU/Linux, "info threads" will display the thread name as set by
2736 prctl or pthread_setname_np.
2738 There is also a new command, "thread name", which can be used to
2739 assign a name internally for GDB to display.
2742 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2743 has been integrated into GDB.
2747 ** The function gdb.Write now accepts an optional keyword 'stream'.
2748 This keyword, when provided, will direct the output to either
2749 stdout, stderr, or GDB's logging output.
2751 ** Parameters can now be be sub-classed in Python, and in particular
2752 you may implement the get_set_doc and get_show_doc functions.
2753 This improves how Parameter set/show documentation is processed
2754 and allows for more dynamic content.
2756 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2757 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2758 have an is_valid method.
2760 ** Breakpoints can now be sub-classed in Python, and in particular
2761 you may implement a 'stop' function that is executed each time
2762 the inferior reaches that breakpoint.
2764 ** New function gdb.lookup_global_symbol looks up a global symbol.
2766 ** GDB values in Python are now callable if the value represents a
2767 function. For example, if 'some_value' represents a function that
2768 takes two integer parameters and returns a value, you can call
2769 that function like so:
2771 result = some_value (10,20)
2773 ** Module gdb.types has been added.
2774 It contains a collection of utilities for working with gdb.Types objects:
2775 get_basic_type, has_field, make_enum_dict.
2777 ** Module gdb.printing has been added.
2778 It contains utilities for writing and registering pretty-printers.
2779 New classes: PrettyPrinter, SubPrettyPrinter,
2780 RegexpCollectionPrettyPrinter.
2781 New function: register_pretty_printer.
2783 ** New commands "info pretty-printers", "enable pretty-printer" and
2784 "disable pretty-printer" have been added.
2786 ** gdb.parameter("directories") is now available.
2788 ** New function gdb.newest_frame returns the newest frame in the
2791 ** The gdb.InferiorThread class has a new "name" attribute. This
2792 holds the thread's name.
2794 ** Python Support for Inferior events.
2795 Python scripts can add observers to be notified of events
2796 occurring in the process being debugged.
2797 The following events are currently supported:
2798 - gdb.events.cont Continue event.
2799 - gdb.events.exited Inferior exited event.
2800 - gdb.events.stop Signal received, and Breakpoint hit events.
2804 ** GDB now puts template parameters in scope when debugging in an
2805 instantiation. For example, if you have:
2807 template<int X> int func (void) { return X; }
2809 then if you step into func<5>, "print X" will show "5". This
2810 feature requires proper debuginfo support from the compiler; it
2811 was added to GCC 4.5.
2813 ** The motion commands "next", "finish", "until", and "advance" now
2814 work better when exceptions are thrown. In particular, GDB will
2815 no longer lose control of the inferior; instead, the GDB will
2816 stop the inferior at the point at which the exception is caught.
2817 This functionality requires a change in the exception handling
2818 code that was introduced in GCC 4.5.
2820 * GDB now follows GCC's rules on accessing volatile objects when
2821 reading or writing target state during expression evaluation.
2822 One notable difference to prior behavior is that "print x = 0"
2823 no longer generates a read of x; the value of the assignment is
2824 now always taken directly from the value being assigned.
2826 * GDB now has some support for using labels in the program's source in
2827 linespecs. For instance, you can use "advance label" to continue
2828 execution to a label.
2830 * GDB now has support for reading and writing a new .gdb_index
2831 section. This section holds a fast index of DWARF debugging
2832 information and can be used to greatly speed up GDB startup and
2833 operation. See the documentation for `save gdb-index' for details.
2835 * The "watch" command now accepts an optional "-location" argument.
2836 When used, this causes GDB to watch the memory referred to by the
2837 expression. Such a watchpoint is never deleted due to it going out
2840 * GDB now supports thread debugging of core dumps on GNU/Linux.
2842 GDB now activates thread debugging using the libthread_db library
2843 when debugging GNU/Linux core dumps, similarly to when debugging
2844 live processes. As a result, when debugging a core dump file, GDB
2845 is now able to display pthread_t ids of threads. For example, "info
2846 threads" shows the same output as when debugging the process when it
2847 was live. In earlier releases, you'd see something like this:
2850 * 1 LWP 6780 main () at main.c:10
2852 While now you see this:
2855 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2857 It is also now possible to inspect TLS variables when debugging core
2860 When debugging a core dump generated on a machine other than the one
2861 used to run GDB, you may need to point GDB at the correct
2862 libthread_db library with the "set libthread-db-search-path"
2863 command. See the user manual for more details on this command.
2865 * When natively debugging programs on PowerPC BookE processors running
2866 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2867 which stop execution of the inferior whenever it executes an instruction
2868 at any address within the specified range. See the "PowerPC Embedded"
2869 section in the user manual for more details.
2871 * New features in the GDB remote stub, GDBserver
2873 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2874 and i686 LynxOS (version 5.x).
2876 ** GDBserver is now supported on Blackfin Linux.
2878 * New native configurations
2880 ia64 HP-UX ia64-*-hpux*
2884 Analog Devices, Inc. Blackfin Processor bfin-*
2886 * Ada task switching is now supported on sparc-elf targets when
2887 debugging a program using the Ravenscar Profile. For more information,
2888 see the "Tasking Support when using the Ravenscar Profile" section
2889 in the GDB user manual.
2891 * Guile support was removed.
2893 * New features in the GNU simulator
2895 ** The --map-info flag lists all known core mappings.
2897 ** CFI flashes may be simulated via the "cfi" device.
2899 *** Changes in GDB 7.2
2901 * Shared library support for remote targets by default
2903 When GDB is configured for a generic, non-OS specific target, like
2904 for example, --target=arm-eabi or one of the many *-*-elf targets,
2905 GDB now queries remote stubs for loaded shared libraries using the
2906 `qXfer:libraries:read' packet. Previously, shared library support
2907 was always disabled for such configurations.
2911 ** Argument Dependent Lookup (ADL)
2913 In C++ ADL lookup directs function search to the namespaces of its
2914 arguments even if the namespace has not been imported.
2924 Here the compiler will search for `foo' in the namespace of 'b'
2925 and find A::foo. GDB now supports this. This construct is commonly
2926 used in the Standard Template Library for operators.
2928 ** Improved User Defined Operator Support
2930 In addition to member operators, GDB now supports lookup of operators
2931 defined in a namespace and imported with a `using' directive, operators
2932 defined in the global scope, operators imported implicitly from an
2933 anonymous namespace, and the ADL operators mentioned in the previous
2935 GDB now also supports proper overload resolution for all the previously
2936 mentioned flavors of operators.
2938 ** static const class members
2940 Printing of static const class members that are initialized in the
2941 class definition has been fixed.
2943 * Windows Thread Information Block access.
2945 On Windows targets, GDB now supports displaying the Windows Thread
2946 Information Block (TIB) structure. This structure is visible either
2947 by using the new command `info w32 thread-information-block' or, by
2948 dereferencing the new convenience variable named `$_tlb', a
2949 thread-specific pointer to the TIB. This feature is also supported
2950 when remote debugging using GDBserver.
2952 * Static tracepoints
2954 Static tracepoints are calls in the user program into a tracing
2955 library. One such library is a port of the LTTng kernel tracer to
2956 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2957 When debugging with GDBserver, GDB now supports combining the GDB
2958 tracepoint machinery with such libraries. For example: the user can
2959 use GDB to probe a static tracepoint marker (a call from the user
2960 program into the tracing library) with the new "strace" command (see
2961 "New commands" below). This creates a "static tracepoint" in the
2962 breakpoint list, that can be manipulated with the same feature set
2963 as fast and regular tracepoints. E.g., collect registers, local and
2964 global variables, collect trace state variables, and define
2965 tracepoint conditions. In addition, the user can collect extra
2966 static tracepoint marker specific data, by collecting the new
2967 $_sdata internal variable. When analyzing the trace buffer, you can
2968 inspect $_sdata like any other variable available to GDB. For more
2969 information, see the "Tracepoints" chapter in GDB user manual. New
2970 remote packets have been defined to support static tracepoints, see
2971 the "New remote packets" section below.
2973 * Better reconstruction of tracepoints after disconnected tracing
2975 GDB will attempt to download the original source form of tracepoint
2976 definitions when starting a trace run, and then will upload these
2977 upon reconnection to the target, resulting in a more accurate
2978 reconstruction of the tracepoints that are in use on the target.
2982 You can now exercise direct control over the ways that GDB can
2983 affect your program. For instance, you can disallow the setting of
2984 breakpoints, so that the program can run continuously (assuming
2985 non-stop mode). In addition, the "observer" variable is available
2986 to switch all of the different controls; in observer mode, GDB
2987 cannot affect the target's behavior at all, which is useful for
2988 tasks like diagnosing live systems in the field.
2990 * The new convenience variable $_thread holds the number of the
2993 * New remote packets
2997 Return the address of the Windows Thread Information Block of a given thread.
3001 In response to several of the tracepoint packets, the target may now
3002 also respond with a number of intermediate `qRelocInsn' request
3003 packets before the final result packet, to have GDB handle
3004 relocating an instruction to execute at a different address. This
3005 is particularly useful for stubs that support fast tracepoints. GDB
3006 reports support for this feature in the qSupported packet.
3010 List static tracepoint markers in the target program.
3014 List static tracepoint markers at a given address in the target
3017 qXfer:statictrace:read
3019 Read the static trace data collected (by a `collect $_sdata'
3020 tracepoint action). The remote stub reports support for this packet
3021 to gdb's qSupported query.
3025 Send the current settings of GDB's permission flags.
3029 Send part of the source (textual) form of a tracepoint definition,
3030 which includes location, conditional, and action list.
3032 * The source command now accepts a -s option to force searching for the
3033 script in the source search path even if the script name specifies
3036 * New features in the GDB remote stub, GDBserver
3038 - GDBserver now support tracepoints (including fast tracepoints, and
3039 static tracepoints). The feature is currently supported by the
3040 i386-linux and amd64-linux builds. See the "Tracepoints support
3041 in gdbserver" section in the manual for more information.
3043 GDBserver JIT compiles the tracepoint's conditional agent
3044 expression bytecode into native code whenever possible for low
3045 overhead dynamic tracepoints conditionals. For such tracepoints,
3046 an expression that examines program state is evaluated when the
3047 tracepoint is reached, in order to determine whether to capture
3048 trace data. If the condition is simple and false, processing the
3049 tracepoint finishes very quickly and no data is gathered.
3051 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3052 for static tracepoints support.
3054 - GDBserver now supports x86_64 Windows 64-bit debugging.
3056 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3057 it understands register description.
3059 * The --batch flag now disables pagination and queries.
3061 * X86 general purpose registers
3063 GDB now supports reading/writing byte, word and double-word x86
3064 general purpose registers directly. This means you can use, say,
3065 $ah or $ax to refer, respectively, to the byte register AH and
3066 16-bit word register AX that are actually portions of the 32-bit
3067 register EAX or 64-bit register RAX.
3069 * The `commands' command now accepts a range of breakpoints to modify.
3070 A plain `commands' following a command that creates multiple
3071 breakpoints affects all the breakpoints set by that command. This
3072 applies to breakpoints set by `rbreak', and also applies when a
3073 single `break' command creates multiple breakpoints (e.g.,
3074 breakpoints on overloaded c++ functions).
3076 * The `rbreak' command now accepts a filename specification as part of
3077 its argument, limiting the functions selected by the regex to those
3078 in the specified file.
3080 * Support for remote debugging Windows and SymbianOS shared libraries
3081 from Unix hosts has been improved. Non Windows GDB builds now can
3082 understand target reported file names that follow MS-DOS based file
3083 system semantics, such as file names that include drive letters and
3084 use the backslash character as directory separator. This makes it
3085 possible to transparently use the "set sysroot" and "set
3086 solib-search-path" on Unix hosts to point as host copies of the
3087 target's shared libraries. See the new command "set
3088 target-file-system-kind" described below, and the "Commands to
3089 specify files" section in the user manual for more information.
3093 eval template, expressions...
3094 Convert the values of one or more expressions under the control
3095 of the string template to a command line, and call it.
3097 set target-file-system-kind unix|dos-based|auto
3098 show target-file-system-kind
3099 Set or show the assumed file system kind for target reported file
3102 save breakpoints <filename>
3103 Save all current breakpoint definitions to a file suitable for use
3104 in a later debugging session. To read the saved breakpoint
3105 definitions, use the `source' command.
3107 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3110 info static-tracepoint-markers
3111 Display information about static tracepoint markers in the target.
3113 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3114 Define a static tracepoint by probing a marker at the given
3115 function, line, address, or marker ID.
3119 Enable and disable observer mode.
3121 set may-write-registers on|off
3122 set may-write-memory on|off
3123 set may-insert-breakpoints on|off
3124 set may-insert-tracepoints on|off
3125 set may-insert-fast-tracepoints on|off
3126 set may-interrupt on|off
3127 Set individual permissions for GDB effects on the target. Note that
3128 some of these settings can have undesirable or surprising
3129 consequences, particularly when changed in the middle of a session.
3130 For instance, disabling the writing of memory can prevent
3131 breakpoints from being inserted, cause single-stepping to fail, or
3132 even crash your program, if you disable after breakpoints have been
3133 inserted. However, GDB should not crash.
3135 set record memory-query on|off
3136 show record memory-query
3137 Control whether to stop the inferior if memory changes caused
3138 by an instruction cannot be recorded.
3143 The disassemble command now supports "start,+length" form of two arguments.
3147 ** GDB now provides a new directory location, called the python directory,
3148 where Python scripts written for GDB can be installed. The location
3149 of that directory is <data-directory>/python, where <data-directory>
3150 is the GDB data directory. For more details, see section `Scripting
3151 GDB using Python' in the manual.
3153 ** The GDB Python API now has access to breakpoints, symbols, symbol
3154 tables, program spaces, inferiors, threads and frame's code blocks.
3155 Additionally, GDB Parameters can now be created from the API, and
3156 manipulated via set/show in the CLI.
3158 ** New functions gdb.target_charset, gdb.target_wide_charset,
3159 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3161 ** New exception gdb.GdbError.
3163 ** Pretty-printers are now also looked up in the current program space.
3165 ** Pretty-printers can now be individually enabled and disabled.
3167 ** GDB now looks for names of Python scripts to auto-load in a
3168 special section named `.debug_gdb_scripts', in addition to looking
3169 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3171 * Tracepoint actions were unified with breakpoint commands. In particular,
3172 there are no longer differences in "info break" output for breakpoints and
3173 tracepoints and the "commands" command can be used for both tracepoints and
3174 regular breakpoints.
3178 ARM Symbian arm*-*-symbianelf*
3180 * D language support.
3181 GDB now supports debugging programs written in the D programming
3184 * GDB now supports the extended ptrace interface for PowerPC which is
3185 available since Linux kernel version 2.6.34. This automatically enables
3186 any hardware breakpoints and additional hardware watchpoints available in
3187 the processor. The old ptrace interface exposes just one hardware
3188 watchpoint and no hardware breakpoints.
3190 * GDB is now able to use the Data Value Compare (DVC) register available on
3191 embedded PowerPC processors to implement in hardware simple watchpoint
3192 conditions of the form:
3194 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3196 This works in native GDB running on Linux kernels with the extended ptrace
3197 interface mentioned above.
3199 *** Changes in GDB 7.1
3203 ** Namespace Support
3205 GDB now supports importing of namespaces in C++. This enables the
3206 user to inspect variables from imported namespaces. Support for
3207 namepace aliasing has also been added. So, if a namespace is
3208 aliased in the current scope (e.g. namepace C=A; ) the user can
3209 print variables using the alias (e.g. (gdb) print C::x).
3213 All known bugs relating to the printing of virtual base class were
3214 fixed. It is now possible to call overloaded static methods using a
3219 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3220 and reinterpret_cast<> are now handled by the C++ expression parser.
3224 Xilinx MicroBlaze microblaze-*-*
3229 Xilinx MicroBlaze microblaze
3232 * Multi-program debugging.
3234 GDB now has support for multi-program (a.k.a. multi-executable or
3235 multi-exec) debugging. This allows for debugging multiple inferiors
3236 simultaneously each running a different program under the same GDB
3237 session. See "Debugging Multiple Inferiors and Programs" in the
3238 manual for more information. This implied some user visible changes
3239 in the multi-inferior support. For example, "info inferiors" now
3240 lists inferiors that are not running yet or that have exited
3241 already. See also "New commands" and "New options" below.
3243 * New tracing features
3245 GDB's tracepoint facility now includes several new features:
3247 ** Trace state variables
3249 GDB tracepoints now include support for trace state variables, which
3250 are variables managed by the target agent during a tracing
3251 experiment. They are useful for tracepoints that trigger each
3252 other, so for instance one tracepoint can count hits in a variable,
3253 and then a second tracepoint has a condition that is true when the
3254 count reaches a particular value. Trace state variables share the
3255 $-syntax of GDB convenience variables, and can appear in both
3256 tracepoint actions and condition expressions. Use the "tvariable"
3257 command to create, and "info tvariables" to view; see "Trace State
3258 Variables" in the manual for more detail.
3262 GDB now includes an option for defining fast tracepoints, which
3263 targets may implement more efficiently, such as by installing a jump
3264 into the target agent rather than a trap instruction. The resulting
3265 speedup can be by two orders of magnitude or more, although the
3266 tradeoff is that some program locations on some target architectures
3267 might not allow fast tracepoint installation, for instance if the
3268 instruction to be replaced is shorter than the jump. To request a
3269 fast tracepoint, use the "ftrace" command, with syntax identical to
3270 the regular trace command.
3272 ** Disconnected tracing
3274 It is now possible to detach GDB from the target while it is running
3275 a trace experiment, then reconnect later to see how the experiment
3276 is going. In addition, a new variable disconnected-tracing lets you
3277 tell the target agent whether to continue running a trace if the
3278 connection is lost unexpectedly.
3282 GDB now has the ability to save the trace buffer into a file, and
3283 then use that file as a target, similarly to you can do with
3284 corefiles. You can select trace frames, print data that was
3285 collected in them, and use tstatus to display the state of the
3286 tracing run at the moment that it was saved. To create a trace
3287 file, use "tsave <filename>", and to use it, do "target tfile
3290 ** Circular trace buffer
3292 You can ask the target agent to handle the trace buffer as a
3293 circular buffer, discarding the oldest trace frames to make room for
3294 newer ones, by setting circular-trace-buffer to on. This feature may
3295 not be available for all target agents.
3300 The disassemble command, when invoked with two arguments, now requires
3301 the arguments to be comma-separated.
3304 The info variables command now displays variable definitions. Files
3305 which only declare a variable are not shown.
3308 The source command is now capable of sourcing Python scripts.
3309 This feature is dependent on the debugger being build with Python
3312 Related to this enhancement is also the introduction of a new command
3313 "set script-extension" (see below).
3315 * New commands (for set/show, see "New options" below)
3317 record save [<FILENAME>]
3318 Save a file (in core file format) containing the process record
3319 execution log for replay debugging at a later time.
3321 record restore <FILENAME>
3322 Restore the process record execution log that was saved at an
3323 earlier time, for replay debugging.
3325 add-inferior [-copies <N>] [-exec <FILENAME>]
3328 clone-inferior [-copies <N>] [ID]
3329 Make a new inferior ready to execute the same program another
3330 inferior has loaded.
3335 maint info program-spaces
3336 List the program spaces loaded into GDB.
3338 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3339 show remote interrupt-sequence
3340 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3341 as the sequence to the remote target in order to interrupt the execution.
3342 Ctrl-C is a default. Some system prefers BREAK which is high level of
3343 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3344 Magic SysRq g. It is BREAK signal and character 'g'.
3346 set remote interrupt-on-connect [on | off]
3347 show remote interrupt-on-connect
3348 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3349 remote target when gdb connects to it. This is needed when you debug
3352 set remotebreak [on | off]
3354 Deprecated. Use "set/show remote interrupt-sequence" instead.
3356 tvariable $NAME [ = EXP ]
3357 Create or modify a trace state variable.
3360 List trace state variables and their values.
3362 delete tvariable $NAME ...
3363 Delete one or more trace state variables.
3366 Evaluate the given expressions without collecting anything into the
3367 trace buffer. (Valid in tracepoint actions only.)
3369 ftrace FN / FILE:LINE / *ADDR
3370 Define a fast tracepoint at the given function, line, or address.
3372 * New expression syntax
3374 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3375 GDB now parses 0b101010 identically with 42.
3379 set follow-exec-mode new|same
3380 show follow-exec-mode
3381 Control whether GDB reuses the same inferior across an exec call or
3382 creates a new one. This is useful to be able to restart the old
3383 executable after the inferior having done an exec call.
3385 set default-collect EXPR, ...
3386 show default-collect
3387 Define a list of expressions to be collected at each tracepoint.
3388 This is a useful way to ensure essential items are not overlooked,
3389 such as registers or a critical global variable.
3391 set disconnected-tracing
3392 show disconnected-tracing
3393 If set to 1, the target is instructed to continue tracing if it
3394 loses its connection to GDB. If 0, the target is to stop tracing
3397 set circular-trace-buffer
3398 show circular-trace-buffer
3399 If set to on, the target is instructed to use a circular trace buffer
3400 and discard the oldest trace frames instead of stopping the trace due
3401 to a full trace buffer. If set to off, the trace stops when the buffer
3402 fills up. Some targets may not support this.
3404 set script-extension off|soft|strict
3405 show script-extension
3406 If set to "off", the debugger does not perform any script language
3407 recognition, and all sourced files are assumed to be GDB scripts.
3408 If set to "soft" (the default), files are sourced according to
3409 filename extension, falling back to GDB scripts if the first
3411 If set to "strict", files are sourced according to filename extension.
3413 set ada trust-PAD-over-XVS on|off
3414 show ada trust-PAD-over-XVS
3415 If off, activate a workaround against a bug in the debugging information
3416 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3417 the GCC sources for more information about the GNAT encoding and
3418 PAD types in particular). It is always safe to set this option to
3419 off, but this introduces a slight performance penalty. The default
3422 * Python API Improvements
3424 ** GDB provides the new class gdb.LazyString. This is useful in
3425 some pretty-printing cases. The new method gdb.Value.lazy_string
3426 provides a simple way to create objects of this type.
3428 ** The fields returned by gdb.Type.fields now have an
3429 `is_base_class' attribute.
3431 ** The new method gdb.Type.range returns the range of an array type.
3433 ** The new method gdb.parse_and_eval can be used to parse and
3434 evaluate an expression.
3436 * New remote packets
3439 Define a trace state variable.
3442 Get the current value of a trace state variable.
3445 Set desired tracing behavior upon disconnection.
3448 Set the trace buffer to be linear or circular.
3451 Get data about the tracepoints currently in use.
3455 Process record now works correctly with hardware watchpoints.
3457 Multiple bug fixes have been made to the mips-irix port, making it
3458 much more reliable. In particular:
3459 - Debugging threaded applications is now possible again. Previously,
3460 GDB would hang while starting the program, or while waiting for
3461 the program to stop at a breakpoint.
3462 - Attaching to a running process no longer hangs.
3463 - An error occurring while loading a core file has been fixed.
3464 - Changing the value of the PC register now works again. This fixes
3465 problems observed when using the "jump" command, or when calling
3466 a function from GDB, or even when assigning a new value to $pc.
3467 - With the "finish" and "return" commands, the return value for functions
3468 returning a small array is now correctly printed.
3469 - It is now possible to break on shared library code which gets executed
3470 during a shared library init phase (code executed while executing
3471 their .init section). Previously, the breakpoint would have no effect.
3472 - GDB is now able to backtrace through the signal handler for
3473 non-threaded programs.
3475 PIE (Position Independent Executable) programs debugging is now supported.
3476 This includes debugging execution of PIC (Position Independent Code) shared
3477 libraries although for that, it should be possible to run such libraries as an
3480 *** Changes in GDB 7.0
3482 * GDB now has an interface for JIT compilation. Applications that
3483 dynamically generate code can create symbol files in memory and register
3484 them with GDB. For users, the feature should work transparently, and
3485 for JIT developers, the interface is documented in the GDB manual in the
3486 "JIT Compilation Interface" chapter.
3488 * Tracepoints may now be conditional. The syntax is as for
3489 breakpoints; either an "if" clause appended to the "trace" command,
3490 or the "condition" command is available. GDB sends the condition to
3491 the target for evaluation using the same bytecode format as is used
3492 for tracepoint actions.
3494 * The disassemble command now supports: an optional /r modifier, print the
3495 raw instructions in hex as well as in symbolic form, and an optional /m
3496 modifier to print mixed source+assembly.
3498 * Process record and replay
3500 In a architecture environment that supports ``process record and
3501 replay'', ``process record and replay'' target can record a log of
3502 the process execution, and replay it with both forward and reverse
3505 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3506 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3507 set execution-direction {forward|reverse}, for targets that support
3510 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3511 feature is available with a native GDB running on kernel version
3514 * GDB now has support for multi-byte and wide character sets on the
3515 target. Strings whose character type is wchar_t, char16_t, or
3516 char32_t are now correctly printed. GDB supports wide- and unicode-
3517 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3518 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3519 `printf'. This feature requires iconv to work properly; if your
3520 system does not have a working iconv, GDB can use GNU libiconv. See
3521 the installation instructions for more information.
3523 * GDB now supports automatic retrieval of shared library files from
3524 remote targets. To use this feature, specify a system root that begins
3525 with the `remote:' prefix, either via the `set sysroot' command or via
3526 the `--with-sysroot' configure-time option.
3528 * "info sharedlibrary" now takes an optional regex of libraries to show,
3529 and it now reports if a shared library has no debugging information.
3531 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3532 now complete on file names.
3534 * When completing in expressions, gdb will attempt to limit
3535 completions to allowable structure or union fields, where appropriate.
3536 For instance, consider:
3538 # struct example { int f1; double f2; };
3539 # struct example variable;
3542 If the user types TAB at the end of this command line, the available
3543 completions will be "f1" and "f2".
3545 * Inlined functions are now supported. They show up in backtraces, and
3546 the "step", "next", and "finish" commands handle them automatically.
3548 * GDB now supports the token-splicing (##) and stringification (#)
3549 operators when expanding macros. It also supports variable-arity
3552 * GDB now supports inspecting extra signal information, exported by
3553 the new $_siginfo convenience variable. The feature is currently
3554 implemented on linux ARM, i386 and amd64.
3556 * GDB can now display the VFP floating point registers and NEON vector
3557 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3558 can provide these registers (requires Linux 2.6.30 or later). Remote
3559 and simulator targets may also provide them.
3561 * New remote packets
3564 Search memory for a sequence of bytes.
3567 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3568 operation over reliable transport links. Use of this packet is
3569 controlled by the `set remote noack-packet' command.
3572 Kill the process with the specified process ID. Use this in preference
3573 to `k' when multiprocess protocol extensions are supported.
3576 Obtains additional operating system information
3580 Read or write additional signal information.
3582 * Removed remote protocol undocumented extension
3584 An undocumented extension to the remote protocol's `S' stop reply
3585 packet that permited the stub to pass a process id was removed.
3586 Remote servers should use the `T' stop reply packet instead.
3588 * GDB now supports multiple function calling conventions according to the
3589 DWARF-2 DW_AT_calling_convention function attribute.
3591 * The SH target utilizes the aforementioned change to distinguish between gcc
3592 and Renesas calling convention. It also adds the new CLI commands
3593 `set/show sh calling-convention'.
3595 * GDB can now read compressed debug sections, as produced by GNU gold
3596 with the --compress-debug-sections=zlib flag.
3598 * 64-bit core files are now supported on AIX.
3600 * Thread switching is now supported on Tru64.
3602 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3603 which will be allocated using malloc later in program execution.
3605 * The qXfer:libraries:read remote procotol packet now allows passing a
3606 list of section offsets.
3608 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3609 conditions handling signals delivered during attach or thread creation
3610 have also been fixed.
3612 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3613 From the user's standpoint, all unqualified instances of True and False
3614 are treated as the standard definitions, regardless of context.
3616 * GDB now parses C++ symbol and type names more flexibly. For
3619 template<typename T> class C { };
3622 GDB will now correctly handle all of:
3624 ptype C<char const *>
3625 ptype C<char const*>
3626 ptype C<const char *>
3627 ptype C<const char*>
3629 * New features in the GDB remote stub, gdbserver
3631 - The "--wrapper" command-line argument tells gdbserver to use a
3632 wrapper program to launch programs for debugging.
3634 - On PowerPC and S/390 targets, it is now possible to use a single
3635 gdbserver executable to debug both 32-bit and 64-bit programs.
3636 (This requires gdbserver itself to be built as a 64-bit executable.)
3638 - gdbserver uses the new noack protocol mode for TCP connections to
3639 reduce communications latency, if also supported and enabled in GDB.
3641 - Support for the sparc64-linux-gnu target is now included in
3644 - The amd64-linux build of gdbserver now supports debugging both
3645 32-bit and 64-bit programs.
3647 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3648 now support hardware watchpoints, and will use them automatically
3653 GDB now has support for scripting using Python. Whether this is
3654 available is determined at configure time.
3656 New GDB commands can now be written in Python.
3658 * Ada tasking support
3660 Ada tasks can now be inspected in GDB. The following commands have
3664 Print the list of Ada tasks.
3666 Print detailed information about task number N.
3668 Print the task number of the current task.
3670 Switch the context of debugging to task number N.
3672 * Support for user-defined prefixed commands. The "define" command can
3673 add new commands to existing prefixes, e.g. "target".
3675 * Multi-inferior, multi-process debugging.
3677 GDB now has generalized support for multi-inferior debugging. See
3678 "Debugging Multiple Inferiors" in the manual for more information.
3679 Although availability still depends on target support, the command
3680 set is more uniform now. The GNU/Linux specific multi-forks support
3681 has been migrated to this new framework. This implied some user
3682 visible changes; see "New commands" and also "Removed commands"
3685 * Target descriptions can now describe the target OS ABI. See the
3686 "Target Description Format" section in the user manual for more
3689 * Target descriptions can now describe "compatible" architectures
3690 to indicate that the target can execute applications for a different
3691 architecture in addition to those for the main target architecture.
3692 See the "Target Description Format" section in the user manual for
3695 * Multi-architecture debugging.
3697 GDB now includes general supports for debugging applications on
3698 hybrid systems that use more than one single processor architecture
3699 at the same time. Each such hybrid architecture still requires
3700 specific support to be added. The only hybrid architecture supported
3701 in this version of GDB is the Cell Broadband Engine.
3703 * GDB now supports integrated debugging of Cell/B.E. applications that
3704 use both the PPU and SPU architectures. To enable support for hybrid
3705 Cell/B.E. debugging, you need to configure GDB to support both the
3706 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3707 --enable-targets configure option.
3709 * Non-stop mode debugging.
3711 For some targets, GDB now supports an optional mode of operation in
3712 which you can examine stopped threads while other threads continue
3713 to execute freely. This is referred to as non-stop mode, with the
3714 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3715 section in the user manual for more information.
3717 To be able to support remote non-stop debugging, a remote stub needs
3718 to implement the non-stop mode remote protocol extensions, as
3719 described in the "Remote Non-Stop" section of the user manual. The
3720 GDB remote stub, gdbserver, has been adjusted to support these
3721 extensions on linux targets.
3723 * New commands (for set/show, see "New options" below)
3725 catch syscall [NAME(S) | NUMBER(S)]
3726 Catch system calls. Arguments, which should be names of system
3727 calls or their numbers, mean catch only those syscalls. Without
3728 arguments, every syscall will be caught. When the inferior issues
3729 any of the specified syscalls, GDB will stop and announce the system
3730 call, both when it is called and when its call returns. This
3731 feature is currently available with a native GDB running on the
3732 Linux Kernel, under the following architectures: x86, x86_64,
3733 PowerPC and PowerPC64.
3735 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3737 Search memory for a sequence of bytes.
3739 maint set python print-stack
3740 maint show python print-stack
3741 Show a stack trace when an error is encountered in a Python script.
3744 Invoke CODE by passing it to the Python interpreter.
3749 These allow macros to be defined, undefined, and listed
3753 Show operating system information about processes.
3756 List the inferiors currently under GDB's control.
3759 Switch focus to inferior number NUM.
3762 Detach from inferior number NUM.
3765 Kill inferior number NUM.
3769 set spu stop-on-load
3770 show spu stop-on-load
3771 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3773 set spu auto-flush-cache
3774 show spu auto-flush-cache
3775 Control whether to automatically flush the software-managed cache
3776 during Cell/B.E. debugging.
3778 set sh calling-convention
3779 show sh calling-convention
3780 Control the calling convention used when calling SH target functions.
3783 show debug timestamp
3784 Control display of timestamps with GDB debugging output.
3786 set disassemble-next-line
3787 show disassemble-next-line
3788 Control display of disassembled source lines or instructions when
3791 set remote noack-packet
3792 show remote noack-packet
3793 Set/show the use of remote protocol QStartNoAckMode packet. See above
3794 under "New remote packets."
3796 set remote query-attached-packet
3797 show remote query-attached-packet
3798 Control use of remote protocol `qAttached' (query-attached) packet.
3800 set remote read-siginfo-object
3801 show remote read-siginfo-object
3802 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3805 set remote write-siginfo-object
3806 show remote write-siginfo-object
3807 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3810 set remote reverse-continue
3811 show remote reverse-continue
3812 Control use of remote protocol 'bc' (reverse-continue) packet.
3814 set remote reverse-step
3815 show remote reverse-step
3816 Control use of remote protocol 'bs' (reverse-step) packet.
3818 set displaced-stepping
3819 show displaced-stepping
3820 Control displaced stepping mode. Displaced stepping is a way to
3821 single-step over breakpoints without removing them from the debuggee.
3822 Also known as "out-of-line single-stepping".
3825 show debug displaced
3826 Control display of debugging info for displaced stepping.
3828 maint set internal-error
3829 maint show internal-error
3830 Control what GDB does when an internal error is detected.
3832 maint set internal-warning
3833 maint show internal-warning
3834 Control what GDB does when an internal warning is detected.
3839 Use a wrapper program to launch programs for debugging.
3841 set multiple-symbols (all|ask|cancel)
3842 show multiple-symbols
3843 The value of this variable can be changed to adjust the debugger behavior
3844 when an expression or a breakpoint location contains an ambiguous symbol
3845 name (an overloaded function name, for instance).
3847 set breakpoint always-inserted
3848 show breakpoint always-inserted
3849 Keep breakpoints always inserted in the target, as opposed to inserting
3850 them when resuming the target, and removing them when the target stops.
3851 This option can improve debugger performance on slow remote targets.
3853 set arm fallback-mode (arm|thumb|auto)
3854 show arm fallback-mode
3855 set arm force-mode (arm|thumb|auto)
3857 These commands control how ARM GDB determines whether instructions
3858 are ARM or Thumb. The default for both settings is auto, which uses
3859 the current CPSR value for instructions without symbols; previous
3860 versions of GDB behaved as if "set arm fallback-mode arm".
3862 set disable-randomization
3863 show disable-randomization
3864 Standalone programs run with the virtual address space randomization enabled
3865 by default on some platforms. This option keeps the addresses stable across
3866 multiple debugging sessions.
3870 Control whether other threads are stopped or not when some thread hits
3875 Requests that asynchronous execution is enabled in the target, if available.
3876 In this case, it's possible to resume target in the background, and interact
3877 with GDB while the target is running. "show target-async" displays the
3878 current state of asynchronous execution of the target.
3880 set target-wide-charset
3881 show target-wide-charset
3882 The target-wide-charset is the name of the character set that GDB
3883 uses when printing characters whose type is wchar_t.
3885 set tcp auto-retry (on|off)
3887 set tcp connect-timeout
3888 show tcp connect-timeout
3889 These commands allow GDB to retry failed TCP connections to a remote stub
3890 with a specified timeout period; this is useful if the stub is launched
3891 in parallel with GDB but may not be ready to accept connections immediately.
3893 set libthread-db-search-path
3894 show libthread-db-search-path
3895 Control list of directories which GDB will search for appropriate
3898 set schedule-multiple (on|off)
3899 show schedule-multiple
3900 Allow GDB to resume all threads of all processes or only threads of
3901 the current process.
3905 Use more aggressive caching for accesses to the stack. This improves
3906 performance of remote debugging (particularly backtraces) without
3907 affecting correctness.
3909 set interactive-mode (on|off|auto)
3910 show interactive-mode
3911 Control whether GDB runs in interactive mode (on) or not (off).
3912 When in interactive mode, GDB waits for the user to answer all
3913 queries. Otherwise, GDB does not wait and assumes the default
3914 answer. When set to auto (the default), GDB determines which
3915 mode to use based on the stdin settings.
3920 For program forks, this is replaced by the new more generic `info
3921 inferiors' command. To list checkpoints, you can still use the
3922 `info checkpoints' command, which was an alias for the `info forks'
3926 Replaced by the new `inferior' command. To switch between
3927 checkpoints, you can still use the `restart' command, which was an
3928 alias for the `fork' command.
3931 This is removed, since some targets don't have a notion of
3932 processes. To switch between processes, you can still use the
3933 `inferior' command using GDB's own inferior number.
3936 For program forks, this is replaced by the new more generic `kill
3937 inferior' command. To delete a checkpoint, you can still use the
3938 `delete checkpoint' command, which was an alias for the `delete
3942 For program forks, this is replaced by the new more generic `detach
3943 inferior' command. To detach a checkpoint, you can still use the
3944 `detach checkpoint' command, which was an alias for the `detach
3947 * New native configurations
3949 x86/x86_64 Darwin i[34567]86-*-darwin*
3951 x86_64 MinGW x86_64-*-mingw*
3955 Lattice Mico32 lm32-*
3956 x86 DICOS i[34567]86-*-dicos*
3957 x86_64 DICOS x86_64-*-dicos*
3960 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3961 (mingw32ce) debugging.
3967 These commands were actually not implemented on any target.
3969 *** Changes in GDB 6.8
3971 * New native configurations
3973 NetBSD/hppa hppa*-*netbsd*
3974 Xtensa GNU/Linux xtensa*-*-linux*
3978 NetBSD/hppa hppa*-*-netbsd*
3979 Xtensa GNU/Lunux xtensa*-*-linux*
3981 * Change in command line behavior -- corefiles vs. process ids.
3983 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3984 attaching to process NUMBER fails, GDB no longer attempts to open a
3985 core file named NUMBER. Attaching to a program using the -c option
3986 is no longer supported. Instead, use the '-p' or '--pid' options.
3988 * GDB can now be built as a native debugger for debugging Windows x86
3989 (mingw32) Portable Executable (PE) programs.
3991 * Pending breakpoints no longer change their number when their address
3994 * GDB now supports breakpoints with multiple locations,
3995 including breakpoints on C++ constructors, inside C++ templates,
3996 and in inlined functions.
3998 * GDB's ability to debug optimized code has been improved. GDB more
3999 accurately identifies function bodies and lexical blocks that occupy
4000 more than one contiguous range of addresses.
4002 * Target descriptions can now describe registers for PowerPC.
4004 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4005 registers on PowerPC targets.
4007 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4008 targets even when the libthread_db library is not available.
4010 * The GDB remote stub, gdbserver, now supports the new file transfer
4011 commands (remote put, remote get, and remote delete).
4013 * The GDB remote stub, gdbserver, now supports run and attach in
4014 extended-remote mode.
4016 * hppa*64*-*-hpux11* target broken
4017 The debugger is unable to start a program and fails with the following
4018 error: "Error trying to get information about dynamic linker".
4019 The gdb-6.7 release is also affected.
4021 * GDB now supports the --enable-targets= configure option to allow
4022 building a single GDB executable that supports multiple remote
4023 target architectures.
4025 * GDB now supports debugging C and C++ programs which use the
4026 Decimal Floating Point extension. In addition, the PowerPC target
4027 now has a set of pseudo-registers to inspect decimal float values
4028 stored in two consecutive float registers.
4030 * The -break-insert MI command can optionally create pending
4033 * Improved support for debugging Ada
4034 Many improvements to the Ada language support have been made. These
4036 - Better support for Ada2005 interface types
4037 - Improved handling of arrays and slices in general
4038 - Better support for Taft-amendment types
4039 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4041 - Improved command completion in Ada
4044 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4049 set print frame-arguments (all|scalars|none)
4050 show print frame-arguments
4051 The value of this variable can be changed to control which argument
4052 values should be printed by the debugger when displaying a frame.
4057 Transfer files to and from a remote target, and delete remote files.
4064 Transfer files to and from a remote target, and delete remote files.
4066 * New remote packets
4073 Open, close, read, write, and delete files on the remote system.
4076 Attach to an existing process on the remote system, in extended-remote
4080 Run a new process on the remote system, in extended-remote mode.
4082 *** Changes in GDB 6.7
4084 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4085 bfd, libiberty and opcodes, as revealed by static analysis donated by
4086 Coverity, Inc. (http://scan.coverity.com).
4088 * When looking up multiply-defined global symbols, GDB will now prefer the
4089 symbol definition in the current shared library if it was built using the
4090 -Bsymbolic linker option.
4092 * When the Text User Interface (TUI) is not configured, GDB will now
4093 recognize the -tui command-line option and print a message that the TUI
4096 * The GDB remote stub, gdbserver, now has lower overhead for high
4097 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4099 * GDB for MIPS targets now autodetects whether a remote target provides
4100 32-bit or 64-bit register values.
4102 * Support for C++ member pointers has been improved.
4104 * GDB now understands XML target descriptions, which specify the
4105 target's overall architecture. GDB can read a description from
4106 a local file or over the remote serial protocol.
4108 * Vectors of single-byte data use a new integer type which is not
4109 automatically displayed as character or string data.
4111 * The /s format now works with the print command. It displays
4112 arrays of single-byte integers and pointers to single-byte integers
4115 * Target descriptions can now describe target-specific registers,
4116 for architectures which have implemented the support (currently
4117 only ARM, M68K, and MIPS).
4119 * GDB and the GDB remote stub, gdbserver, now support the XScale
4122 * The GDB remote stub, gdbserver, has been updated to support
4123 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4124 has been rewritten to use the standard GDB remote protocol.
4126 * GDB can now step into C++ functions which are called through thunks.
4128 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4130 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4131 layout. It also supports a TextSeg= and DataSeg= response when only
4132 segment base addresses (rather than offsets) are available.
4134 * The /i format now outputs any trailing branch delay slot instructions
4135 immediately following the last instruction within the count specified.
4137 * The GDB remote protocol "T" stop reply packet now supports a
4138 "library" response. Combined with the new "qXfer:libraries:read"
4139 packet, this response allows GDB to debug shared libraries on targets
4140 where the operating system manages the list of loaded libraries (e.g.
4141 Windows and SymbianOS).
4143 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4144 (DLLs) on Windows and Windows CE targets.
4146 * GDB now supports a faster verification that a .debug file matches its binary
4147 according to its build-id signature, if the signature is present.
4153 Enable or disable hardware flow control (RTS/CTS) on the serial port
4154 when debugging using remote targets.
4156 set mem inaccessible-by-default
4157 show mem inaccessible-by-default
4158 If the target supplies a memory map, for instance via the remote
4159 protocol's "qXfer:memory-map:read" packet, setting this variable
4160 prevents GDB from accessing memory outside the memory map. This
4161 is useful for targets with memory mapped registers or which react
4162 badly to accesses of unmapped address space.
4164 set breakpoint auto-hw
4165 show breakpoint auto-hw
4166 If the target supplies a memory map, for instance via the remote
4167 protocol's "qXfer:memory-map:read" packet, setting this variable
4168 lets GDB use hardware breakpoints automatically for memory regions
4169 where it can not use software breakpoints. This covers both the
4170 "break" command and internal breakpoints used for other commands
4171 including "next" and "finish".
4174 catch exception unhandled
4175 Stop the program execution when Ada exceptions are raised.
4178 Stop the program execution when an Ada assertion failed.
4182 Set an alternate system root for target files. This is a more
4183 general version of "set solib-absolute-prefix", which is now
4184 an alias to "set sysroot".
4187 Provide extended SPU facility status information. This set of
4188 commands is available only when debugging the Cell/B.E. SPU
4191 * New native configurations
4193 OpenBSD/sh sh*-*openbsd*
4196 unset tdesc filename
4198 Use the specified local file as an XML target description, and do
4199 not query the target for its built-in description.
4203 OpenBSD/sh sh*-*-openbsd*
4204 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4205 Toshiba Media Processor mep-elf
4207 * New remote packets
4210 Ignore the specified signals; pass them directly to the debugged program
4211 without stopping other threads or reporting them to GDB.
4213 qXfer:features:read:
4214 Read an XML target description from the target, which describes its
4219 Read or write contents of an spufs file on the target system. These
4220 packets are available only on the Cell/B.E. SPU architecture.
4222 qXfer:libraries:read:
4223 Report the loaded shared libraries. Combined with new "T" packet
4224 response, this packet allows GDB to debug shared libraries on
4225 targets where the operating system manages the list of loaded
4226 libraries (e.g. Windows and SymbianOS).
4230 Support for these obsolete configurations has been removed.
4238 i[34567]86-*-lynxos*
4239 i[34567]86-*-netware*
4240 i[34567]86-*-sco3.2v5*
4241 i[34567]86-*-sco3.2v4*
4243 i[34567]86-*-sysv4.2*
4246 i[34567]86-*-unixware2*
4247 i[34567]86-*-unixware*
4256 * Other removed features
4263 Various m68k-only ROM monitors.
4270 Various Renesas ROM monitors and debugging interfaces for SH and
4275 Support for a Macraigor serial interface to on-chip debugging.
4276 GDB does not directly support the newer parallel or USB
4281 A debug information format. The predecessor to DWARF 2 and
4282 DWARF 3, which are still supported.
4284 Support for the HP aCC compiler on HP-UX/PA-RISC
4286 SOM-encapsulated symbolic debugging information, automatic
4287 invocation of pxdb, and the aCC custom C++ ABI. This does not
4288 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4289 with aCC can still be debugged on an assembly level.
4291 MIPS ".pdr" sections
4293 A MIPS-specific format used to describe stack frame layout
4294 in debugging information.
4298 GDB could work with an older version of Guile to debug
4299 the interpreter and Scheme programs running in it.
4301 set mips stack-arg-size
4302 set mips saved-gpreg-size
4304 Use "set mips abi" to control parameter passing for MIPS.
4306 *** Changes in GDB 6.6
4311 Cell Broadband Engine SPU spu-elf
4313 * GDB can now be configured as a cross-debugger targeting native Windows
4314 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4315 running on a Windows system over TCP/IP to debug Windows programs.
4317 * The GDB remote stub, gdbserver, has been updated to support Windows and
4318 Cygwin debugging. Both single-threaded and multi-threaded programs are
4321 * The "set trust-readonly-sections" command works again. This command was
4322 broken in GDB 6.3, 6.4, and 6.5.
4324 * The "load" command now supports writing to flash memory, if the remote
4325 stub provides the required support.
4327 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4328 longer requires symbolic debug information (e.g. DWARF-2).
4333 unset substitute-path
4334 show substitute-path
4335 Manage a list of substitution rules that GDB uses to rewrite the name
4336 of the directories where the sources are located. This can be useful
4337 for instance when the sources were moved to a different location
4338 between compilation and debugging.
4342 Print each CLI command as it is executed. Each command is prefixed with
4343 a number of `+' symbols representing the nesting depth.
4344 The source command now has a `-v' option to enable the same feature.
4348 The ARM Demon monitor support (RDP protocol, "target rdp").
4350 Kernel Object Display, an embedded debugging feature which only worked with
4351 an obsolete version of Cisco IOS.
4353 The 'set download-write-size' and 'show download-write-size' commands.
4355 * New remote packets
4358 Tell a stub about GDB client features, and request remote target features.
4359 The first feature implemented is PacketSize, which allows the target to
4360 specify the size of packets it can handle - to minimize the number of
4361 packets required and improve performance when connected to a remote
4365 Fetch an OS auxilliary vector from the remote stub. This packet is a
4366 more efficient replacement for qPart:auxv:read.
4368 qXfer:memory-map:read:
4369 Fetch a memory map from the remote stub, including information about
4370 RAM, ROM, and flash memory devices.
4375 Erase and program a flash memory device.
4377 * Removed remote packets
4380 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4381 used it, and only gdbserver implemented it.
4383 *** Changes in GDB 6.5
4387 Renesas M32C/M16C m32c-elf
4389 Morpho Technologies ms1 ms1-elf
4393 init-if-undefined Initialize a convenience variable, but
4394 only if it doesn't already have a value.
4396 The following commands are presently only implemented for native GNU/Linux:
4398 checkpoint Save a snapshot of the program state.
4400 restart <n> Return the program state to a
4401 previously saved state.
4403 info checkpoints List currently saved checkpoints.
4405 delete-checkpoint <n> Delete a previously saved checkpoint.
4407 set|show detach-on-fork Tell gdb whether to detach from a newly
4408 forked process, or to keep debugging it.
4410 info forks List forks of the user program that
4411 are available to be debugged.
4413 fork <n> Switch to debugging one of several
4414 forks of the user program that are
4415 available to be debugged.
4417 delete-fork <n> Delete a fork from the list of forks
4418 that are available to be debugged (and
4419 kill the forked process).
4421 detach-fork <n> Delete a fork from the list of forks
4422 that are available to be debugged (and
4423 allow the process to continue).
4427 Morpho Technologies ms2 ms1-elf
4429 * Improved Windows host support
4431 GDB now builds as a cross debugger hosted on i686-mingw32, including
4432 native console support, and remote communications using either
4433 network sockets or serial ports.
4435 * Improved Modula-2 language support
4437 GDB can now print most types in the Modula-2 syntax. This includes:
4438 basic types, set types, record types, enumerated types, range types,
4439 pointer types and ARRAY types. Procedure var parameters are correctly
4440 printed and hexadecimal addresses and character constants are also
4441 written in the Modula-2 syntax. Best results can be obtained by using
4442 GNU Modula-2 together with the -gdwarf-2 command line option.
4446 The ARM rdi-share module.
4448 The Netware NLM debug server.
4450 *** Changes in GDB 6.4
4452 * New native configurations
4454 OpenBSD/arm arm*-*-openbsd*
4455 OpenBSD/mips64 mips64-*-openbsd*
4459 Morpho Technologies ms1 ms1-elf
4461 * New command line options
4463 --batch-silent As for --batch, but totally silent.
4464 --return-child-result The debugger will exist with the same value
4465 the child (debugged) program exited with.
4466 --eval-command COMMAND, -ex COMMAND
4467 Execute a single GDB CLI command. This may be
4468 specified multiple times and in conjunction
4469 with the --command (-x) option.
4471 * Deprecated commands removed
4473 The following commands, that were deprecated in 2000, have been
4477 set|show arm disassembly-flavor set|show arm disassembler
4478 othernames set arm disassembler
4479 set|show remotedebug set|show debug remote
4480 set|show archdebug set|show debug arch
4481 set|show eventdebug set|show debug event
4484 * New BSD user-level threads support
4486 It is now possible to debug programs using the user-level threads
4487 library on OpenBSD and FreeBSD. Currently supported (target)
4490 FreeBSD/amd64 x86_64-*-freebsd*
4491 FreeBSD/i386 i386-*-freebsd*
4492 OpenBSD/i386 i386-*-openbsd*
4494 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4495 are not yet supported.
4497 * New support for Matsushita MN10300 w/sim added
4498 (Work in progress). mn10300-elf.
4500 * REMOVED configurations and files
4502 VxWorks and the XDR protocol *-*-vxworks
4503 Motorola MCORE mcore-*-*
4504 National Semiconductor NS32000 ns32k-*-*
4506 * New "set print array-indexes" command
4508 After turning this setting "on", GDB prints the index of each element
4509 when displaying arrays. The default is "off" to preserve the previous
4512 * VAX floating point support
4514 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4516 * User-defined command support
4518 In addition to using $arg0..$arg9 for argument passing, it is now possible
4519 to use $argc to determine now many arguments have been passed. See the
4520 section on user-defined commands in the user manual for more information.
4522 *** Changes in GDB 6.3:
4524 * New command line option
4526 GDB now accepts -l followed by a number to set the timeout for remote
4529 * GDB works with GCC -feliminate-dwarf2-dups
4531 GDB now supports a more compact representation of DWARF-2 debug
4532 information using DW_FORM_ref_addr references. These are produced
4533 by GCC with the option -feliminate-dwarf2-dups and also by some
4534 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4535 to use -feliminate-dwarf2-dups.
4537 * Internationalization
4539 When supported by the host system, GDB will be built with
4540 internationalization (libintl). The task of marking up the sources is
4541 continued, we're looking forward to our first translation.
4545 Initial support for debugging programs compiled with the GNAT
4546 implementation of the Ada programming language has been integrated
4547 into GDB. In this release, support is limited to expression evaluation.
4549 * New native configurations
4551 GNU/Linux/m32r m32r-*-linux-gnu
4555 GDB's remote protocol now includes support for the 'p' packet. This
4556 packet is used to fetch individual registers from a remote inferior.
4558 * END-OF-LIFE registers[] compatibility module
4560 GDB's internal register infrastructure has been completely rewritten.
4561 The new infrastructure making possible the implementation of key new
4562 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4565 GDB 6.3 will be the last release to include the the registers[]
4566 compatibility module that allowed out-of-date configurations to
4567 continue to work. This change directly impacts the following
4577 powerpc bdm protocol
4579 Unless there is activity to revive these configurations, they will be
4580 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4582 * OBSOLETE configurations and files
4584 Configurations that have been declared obsolete in this release have
4585 been commented out. Unless there is activity to revive these
4586 configurations, the next release of GDB will have their sources
4587 permanently REMOVED.
4596 *** Changes in GDB 6.2.1:
4598 * MIPS `break main; run' gave an heuristic-fence-post warning
4600 When attempting to run even a simple program, a warning about
4601 heuristic-fence-post being hit would be reported. This problem has
4604 * MIPS IRIX 'long double' crashed GDB
4606 When examining a long double variable, GDB would get a segmentation
4607 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4608 IRIX long double values).
4612 A bug in the VAX stack code was causing problems with the "next"
4613 command. This problem has been fixed.
4615 *** Changes in GDB 6.2:
4617 * Fix for ``many threads''
4619 On GNU/Linux systems that use the NPTL threads library, a program
4620 rapidly creating and deleting threads would confuse GDB leading to the
4623 ptrace: No such process.
4624 thread_db_get_info: cannot get thread info: generic error
4626 This problem has been fixed.
4628 * "-async" and "-noasync" options removed.
4630 Support for the broken "-noasync" option has been removed (it caused
4633 * New ``start'' command.
4635 This command runs the program until the begining of the main procedure.
4637 * New BSD Kernel Data Access Library (libkvm) interface
4639 Using ``target kvm'' it is now possible to debug kernel core dumps and
4640 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4641 platforms. Currently supported (native-only) configurations are:
4643 FreeBSD/amd64 x86_64-*-freebsd*
4644 FreeBSD/i386 i?86-*-freebsd*
4645 NetBSD/i386 i?86-*-netbsd*
4646 NetBSD/m68k m68*-*-netbsd*
4647 NetBSD/sparc sparc-*-netbsd*
4648 OpenBSD/amd64 x86_64-*-openbsd*
4649 OpenBSD/i386 i?86-*-openbsd*
4650 OpenBSD/m68k m68*-openbsd*
4651 OpenBSD/sparc sparc-*-openbsd*
4653 * Signal trampoline code overhauled
4655 Many generic problems with GDB's signal handling code have been fixed.
4656 These include: backtraces through non-contiguous stacks; recognition
4657 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4658 call; backtrace through a signal trampoline; step into and out of
4659 signal handlers; and single-stepping in the signal trampoline.
4661 Please note that kernel bugs are a limiting factor here. These
4662 features have been shown to work on an s390 GNU/Linux system that
4663 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4665 * Cygwin support for DWARF 2 added.
4667 * New native configurations
4669 GNU/Linux/hppa hppa*-*-linux*
4670 OpenBSD/hppa hppa*-*-openbsd*
4671 OpenBSD/m68k m68*-*-openbsd*
4672 OpenBSD/m88k m88*-*-openbsd*
4673 OpenBSD/powerpc powerpc-*-openbsd*
4674 NetBSD/vax vax-*-netbsd*
4675 OpenBSD/vax vax-*-openbsd*
4677 * END-OF-LIFE frame compatibility module
4679 GDB's internal frame infrastructure has been completely rewritten.
4680 The new infrastructure making it possible to support key new features
4681 including DWARF 2 Call Frame Information. To aid in the task of
4682 migrating old configurations to this new infrastructure, a
4683 compatibility module, that allowed old configurations to continue to
4684 work, was also included.
4686 GDB 6.2 will be the last release to include this frame compatibility
4687 module. This change directly impacts the following configurations:
4697 Unless there is activity to revive these configurations, they will be
4698 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4700 * REMOVED configurations and files
4702 Sun 3, running SunOS 3 m68*-*-sunos3*
4703 Sun 3, running SunOS 4 m68*-*-sunos4*
4704 Sun 2, running SunOS 3 m68000-*-sunos3*
4705 Sun 2, running SunOS 4 m68000-*-sunos4*
4706 Motorola 680x0 running LynxOS m68*-*-lynxos*
4707 AT&T 3b1/Unix pc m68*-att-*
4708 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4709 decstation mips-dec-* mips-little-*
4710 riscos mips-*-riscos* mips-*-sysv*
4711 sonymips mips-sony-*
4712 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4714 *** Changes in GDB 6.1.1:
4716 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4718 The TUI (Text-mode User Interface) is now built as part of a default
4719 GDB configuration. It is enabled by either selecting the TUI with the
4720 command line option "-i=tui" or by running the separate "gdbtui"
4721 program. For more information on the TUI, see the manual "Debugging
4724 * Pending breakpoint support (also included in GDB 6.1)
4726 Support has been added to allow you to specify breakpoints in shared
4727 libraries that have not yet been loaded. If a breakpoint location
4728 cannot be found, and the "breakpoint pending" option is set to auto,
4729 GDB queries you if you wish to make the breakpoint pending on a future
4730 shared-library load. If and when GDB resolves the breakpoint symbol,
4731 the pending breakpoint is removed as one or more regular breakpoints
4734 Pending breakpoints are very useful for GCJ Java debugging.
4736 * Fixed ISO-C build problems
4738 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4739 non ISO-C code that stopped them being built using a more strict ISO-C
4740 compiler (e.g., IBM's C compiler).
4742 * Fixed build problem on IRIX 5
4744 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4745 wasn't able to compile compile on an IRIX 5 system.
4747 * Added execute permission to gdb/gdbserver/configure
4749 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4750 permission. This bug would cause configure to fail on a number of
4751 systems (Solaris, IRIX). Ref: server/519.
4753 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4755 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4756 has been updated to use constant array sizes.
4758 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4760 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4761 its generated DWARF Call Frame Info. This encoding was causing GDB to
4762 panic, that panic has been fixed. Ref: gdb/1628.
4764 * Fixed a problem when examining parameters in shared library code.
4766 When examining parameters in optimized shared library code generated
4767 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4768 not available''. GDB now correctly displays the variable's value.
4770 *** Changes in GDB 6.1:
4772 * Removed --with-mmalloc
4774 Support for the mmalloc memory manager has been removed, as it
4775 conflicted with the internal gdb byte cache.
4777 * Changes in AMD64 configurations
4779 The AMD64 target now includes the %cs and %ss registers. As a result
4780 the AMD64 remote protocol has changed; this affects the floating-point
4781 and SSE registers. If you rely on those registers for your debugging,
4782 you should upgrade gdbserver on the remote side.
4784 * Revised SPARC target
4786 The SPARC target has been completely revised, incorporating the
4787 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4788 support for LynxOS and SunOS 4 has been dropped. Calling functions
4789 from within GDB on operating systems with a non-executable stack
4790 (Solaris, OpenBSD) now works.
4794 GDB has a new C++ demangler which does a better job on the mangled
4795 names generated by current versions of g++. It also runs faster, so
4796 with this and other changes gdb should now start faster on large C++
4799 * DWARF 2 Location Expressions
4801 GDB support for location expressions has been extended to support function
4802 arguments and frame bases. Older versions of GDB could crash when they
4805 * C++ nested types and namespaces
4807 GDB's support for nested types and namespaces in C++ has been
4808 improved, especially if you use the DWARF 2 debugging format. (This
4809 is the default for recent versions of GCC on most platforms.)
4810 Specifically, if you have a class "Inner" defined within a class or
4811 namespace "Outer", then GDB realizes that the class's name is
4812 "Outer::Inner", not simply "Inner". This should greatly reduce the
4813 frequency of complaints about not finding RTTI symbols. In addition,
4814 if you are stopped at inside of a function defined within a namespace,
4815 GDB modifies its name lookup accordingly.
4817 * New native configurations
4819 NetBSD/amd64 x86_64-*-netbsd*
4820 OpenBSD/amd64 x86_64-*-openbsd*
4821 OpenBSD/alpha alpha*-*-openbsd*
4822 OpenBSD/sparc sparc-*-openbsd*
4823 OpenBSD/sparc64 sparc64-*-openbsd*
4825 * New debugging protocols
4827 M32R with SDI protocol m32r-*-elf*
4829 * "set prompt-escape-char" command deleted.
4831 The command "set prompt-escape-char" has been deleted. This command,
4832 and its very obscure effet on GDB's prompt, was never documented,
4833 tested, nor mentioned in the NEWS file.
4835 * OBSOLETE configurations and files
4837 Configurations that have been declared obsolete in this release have
4838 been commented out. Unless there is activity to revive these
4839 configurations, the next release of GDB will have their sources
4840 permanently REMOVED.
4842 Sun 3, running SunOS 3 m68*-*-sunos3*
4843 Sun 3, running SunOS 4 m68*-*-sunos4*
4844 Sun 2, running SunOS 3 m68000-*-sunos3*
4845 Sun 2, running SunOS 4 m68000-*-sunos4*
4846 Motorola 680x0 running LynxOS m68*-*-lynxos*
4847 AT&T 3b1/Unix pc m68*-att-*
4848 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4849 decstation mips-dec-* mips-little-*
4850 riscos mips-*-riscos* mips-*-sysv*
4851 sonymips mips-sony-*
4852 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4854 * REMOVED configurations and files
4856 SGI Irix-4.x mips-sgi-irix4 or iris4
4857 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4858 Z8000 simulator z8k-zilog-none or z8ksim
4859 Matsushita MN10200 w/simulator mn10200-*-*
4860 H8/500 simulator h8500-hitachi-hms or h8500hms
4861 HP/PA running BSD hppa*-*-bsd*
4862 HP/PA running OSF/1 hppa*-*-osf*
4863 HP/PA Pro target hppa*-*-pro*
4864 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4865 386BSD i[3456]86-*-bsd*
4866 Sequent family i[3456]86-sequent-sysv4*
4867 i[3456]86-sequent-sysv*
4868 i[3456]86-sequent-bsd*
4869 SPARC running LynxOS sparc-*-lynxos*
4870 SPARC running SunOS 4 sparc-*-sunos4*
4871 Tsqware Sparclet sparclet-*-*
4872 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4874 *** Changes in GDB 6.0:
4878 Support for debugging the Objective-C programming language has been
4879 integrated into GDB.
4881 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4883 DWARF 2's Call Frame Information makes available compiler generated
4884 information that more exactly describes the program's run-time stack.
4885 By using this information, GDB is able to provide more robust stack
4888 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4889 have been updated to use a new backtrace mechanism which includes
4890 DWARF 2 CFI support.
4894 GDB's remote protocol has been extended to include support for hosted
4895 file I/O (where the remote target uses GDB's file system). See GDB's
4896 remote protocol documentation for details.
4898 * All targets using the new architecture framework.
4900 All of GDB's targets have been updated to use the new internal
4901 architecture framework. The way is now open for future GDB releases
4902 to include cross-architecture native debugging support (i386 on amd64,
4905 * GNU/Linux's Thread Local Storage (TLS)
4907 GDB now includes support for for the GNU/Linux implementation of
4908 per-thread variables.
4910 * GNU/Linux's Native POSIX Thread Library (NPTL)
4912 GDB's thread code has been updated to work with either the new
4913 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4915 * Separate debug info.
4917 GDB, in conjunction with BINUTILS, now supports a mechanism for
4918 automatically loading debug information from a separate file. Instead
4919 of shipping full debug and non-debug versions of system libraries,
4920 system integrators can now instead ship just the stripped libraries
4921 and optional debug files.
4923 * DWARF 2 Location Expressions
4925 DWARF 2 Location Expressions allow the compiler to more completely
4926 describe the location of variables (even in optimized code) to the
4929 GDB now includes preliminary support for location expressions (support
4930 for DW_OP_piece is still missing).
4934 A number of long standing bugs that caused GDB to die while starting a
4935 Java application have been fixed. GDB's Java support is now
4936 considered "useable".
4938 * GNU/Linux support for fork, vfork, and exec.
4940 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4941 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4944 * GDB supports logging output to a file
4946 There are two new commands, "set logging" and "show logging", which can be
4947 used to capture GDB's output to a file.
4949 * The meaning of "detach" has changed for gdbserver
4951 The "detach" command will now resume the application, as documented. To
4952 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4955 * d10v, m68hc11 `regs' command deprecated
4957 The `info registers' command has been updated so that it displays the
4958 registers using a format identical to the old `regs' command.
4962 A new command, "maint set profile on/off", has been added. This command can
4963 be used to enable or disable profiling while running GDB, to profile a
4964 session or a set of commands. In addition there is a new configure switch,
4965 "--enable-profiling", which will cause GDB to be compiled with profiling
4966 data, for more informative profiling results.
4968 * Default MI syntax changed to "mi2".
4970 The default MI (machine interface) syntax, enabled by the command line
4971 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4972 "mi1", can be enabled by specifying the option "-i=mi1".
4974 Support for the original "mi0" syntax (included in GDB 5.0) has been
4977 Fix for gdb/192: removed extraneous space when displaying frame level.
4978 Fix for gdb/672: update changelist is now output in mi list format.
4979 Fix for gdb/702: a -var-assign that updates the value now shows up
4980 in a subsequent -var-update.
4982 * New native configurations.
4984 FreeBSD/amd64 x86_64-*-freebsd*
4986 * Multi-arched targets.
4988 HP/PA HPUX11 hppa*-*-hpux*
4989 Renesas M32R/D w/simulator m32r-*-elf*
4991 * OBSOLETE configurations and files
4993 Configurations that have been declared obsolete in this release have
4994 been commented out. Unless there is activity to revive these
4995 configurations, the next release of GDB will have their sources
4996 permanently REMOVED.
4998 Z8000 simulator z8k-zilog-none or z8ksim
4999 Matsushita MN10200 w/simulator mn10200-*-*
5000 H8/500 simulator h8500-hitachi-hms or h8500hms
5001 HP/PA running BSD hppa*-*-bsd*
5002 HP/PA running OSF/1 hppa*-*-osf*
5003 HP/PA Pro target hppa*-*-pro*
5004 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5005 Sequent family i[3456]86-sequent-sysv4*
5006 i[3456]86-sequent-sysv*
5007 i[3456]86-sequent-bsd*
5008 Tsqware Sparclet sparclet-*-*
5009 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5011 * REMOVED configurations and files
5014 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5015 IBM AIX PS/2 i[3456]86-*-aix
5016 i386 running Mach 3.0 i[3456]86-*-mach3*
5017 i386 running Mach i[3456]86-*-mach*
5018 i386 running OSF/1 i[3456]86-*osf1mk*
5019 HP/Apollo 68k Family m68*-apollo*-sysv*,
5021 m68*-hp-bsd*, m68*-hp-hpux*
5022 Argonaut Risc Chip (ARC) arc-*-*
5023 Mitsubishi D30V d30v-*-*
5024 Fujitsu FR30 fr30-*-elf*
5025 OS/9000 i[34]86-*-os9k
5026 I960 with MON960 i960-*-coff
5028 * MIPS $fp behavior changed
5030 The convenience variable $fp, for the MIPS, now consistently returns
5031 the address of the current frame's base. Previously, depending on the
5032 context, $fp could refer to either $sp or the current frame's base
5033 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5034 The GNU Source-Level Debugger''.
5036 *** Changes in GDB 5.3:
5038 * GNU/Linux shared library multi-threaded performance improved.
5040 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5041 `/proc', in preference to `ptrace' for memory reads. This may result
5042 in an improvement in the start-up time of multi-threaded, shared
5043 library applications when run under GDB. One GDB user writes: ``loads
5044 shared libs like mad''.
5046 * ``gdbserver'' now supports multi-threaded applications on some targets
5048 Support for debugging multi-threaded applications which use
5049 the GNU/Linux LinuxThreads package has been added for
5050 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5051 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5053 * GDB now supports C/C++ preprocessor macros.
5055 GDB now expands preprocessor macro invocations in C/C++ expressions,
5056 and provides various commands for showing macro definitions and how
5059 The new command `macro expand EXPRESSION' expands any macro
5060 invocations in expression, and shows the result.
5062 The new command `show macro MACRO-NAME' shows the definition of the
5063 macro named MACRO-NAME, and where it was defined.
5065 Most compilers don't include information about macros in the debugging
5066 information by default. In GCC 3.1, for example, you need to compile
5067 your program with the options `-gdwarf-2 -g3'. If the macro
5068 information is present in the executable, GDB will read it.
5070 * Multi-arched targets.
5072 DEC Alpha (partial) alpha*-*-*
5073 DEC VAX (partial) vax-*-*
5075 National Semiconductor NS32000 (partial) ns32k-*-*
5076 Motorola 68000 (partial) m68k-*-*
5077 Motorola MCORE mcore-*-*
5081 Fujitsu FRV architecture added by Red Hat frv*-*-*
5084 * New native configurations
5086 Alpha NetBSD alpha*-*-netbsd*
5087 SH NetBSD sh*-*-netbsdelf*
5088 MIPS NetBSD mips*-*-netbsd*
5089 UltraSPARC NetBSD sparc64-*-netbsd*
5091 * OBSOLETE configurations and files
5093 Configurations that have been declared obsolete in this release have
5094 been commented out. Unless there is activity to revive these
5095 configurations, the next release of GDB will have their sources
5096 permanently REMOVED.
5098 Mitsubishi D30V d30v-*-*
5099 OS/9000 i[34]86-*-os9k
5100 IBM AIX PS/2 i[3456]86-*-aix
5101 Fujitsu FR30 fr30-*-elf*
5102 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5103 Argonaut Risc Chip (ARC) arc-*-*
5104 i386 running Mach 3.0 i[3456]86-*-mach3*
5105 i386 running Mach i[3456]86-*-mach*
5106 i386 running OSF/1 i[3456]86-*osf1mk*
5107 HP/Apollo 68k Family m68*-apollo*-sysv*,
5109 m68*-hp-bsd*, m68*-hp-hpux*
5110 I960 with MON960 i960-*-coff
5112 * OBSOLETE languages
5114 CHILL, a Pascal like language used by telecommunications companies.
5116 * REMOVED configurations and files
5118 AMD 29k family via UDI a29k-amd-udi, udi29k
5119 A29K VxWorks a29k-*-vxworks
5120 AMD 29000 embedded, using EBMON a29k-none-none
5121 AMD 29000 embedded with COFF a29k-none-coff
5122 AMD 29000 embedded with a.out a29k-none-aout
5124 testsuite/gdb.hp/gdb.threads-hp/ directory
5126 * New command "set max-user-call-depth <nnn>"
5128 This command allows the user to limit the call depth of user-defined
5129 commands. The default is 1024.
5131 * Changes in FreeBSD/i386 native debugging.
5133 Support for the "generate-core-file" has been added.
5135 * New commands "dump", "append", and "restore".
5137 These commands allow data to be copied from target memory
5138 to a bfd-format or binary file (dump and append), and back
5139 from a file into memory (restore).
5141 * Improved "next/step" support on multi-processor Alpha Tru64.
5143 The previous single-step mechanism could cause unpredictable problems,
5144 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5145 of a software single-step mechanism prevents this.
5147 *** Changes in GDB 5.2.1:
5155 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5156 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5157 Fix, by Joel Brobecker imported from mainline.
5159 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5160 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5161 Fix, by Fred Fish, imported from mainline.
5163 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5164 Surprisingly enough, it works now.
5165 By Michal Ludvig, imported from mainline.
5167 i386 hardware watchpoint support:
5168 avoid misses on second run for some targets.
5169 By Pierre Muller, imported from mainline.
5171 *** Changes in GDB 5.2:
5173 * New command "set trust-readonly-sections on[off]".
5175 This command is a hint that tells gdb that read-only sections
5176 really are read-only (ie. that their contents will not change).
5177 In this mode, gdb will go to the object file rather than the
5178 target to read memory from read-only sections (such as ".text").
5179 This can be a significant performance improvement on some
5180 (notably embedded) targets.
5182 * New command "generate-core-file" (or "gcore").
5184 This new gdb command allows the user to drop a core file of the child
5185 process state at any time. So far it's been implemented only for
5186 GNU/Linux and Solaris, but should be relatively easily ported to other
5187 hosts. Argument is core file name (defaults to core.<pid>).
5189 * New command line option
5191 GDB now accepts --pid or -p followed by a process id.
5193 * Change in command line behavior -- corefiles vs. process ids.
5195 There is a subtle behavior in the way in which GDB handles
5196 command line arguments. The first non-flag argument is always
5197 a program to debug, but the second non-flag argument may either
5198 be a corefile or a process id. Previously, GDB would attempt to
5199 open the second argument as a corefile, and if that failed, would
5200 issue a superfluous error message and then attempt to attach it as
5201 a process. Now, if the second argument begins with a non-digit,
5202 it will be treated as a corefile. If it begins with a digit,
5203 GDB will attempt to attach it as a process, and if no such process
5204 is found, will then attempt to open it as a corefile.
5206 * Changes in ARM configurations.
5208 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5209 configuration is fully multi-arch.
5211 * New native configurations
5213 ARM NetBSD arm*-*-netbsd*
5214 x86 OpenBSD i[3456]86-*-openbsd*
5215 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5216 Sparc64 running FreeBSD sparc64-*-freebsd*
5220 Sanyo XStormy16 xstormy16-elf
5222 * OBSOLETE configurations and files
5224 Configurations that have been declared obsolete in this release have
5225 been commented out. Unless there is activity to revive these
5226 configurations, the next release of GDB will have their sources
5227 permanently REMOVED.
5229 AMD 29k family via UDI a29k-amd-udi, udi29k
5230 A29K VxWorks a29k-*-vxworks
5231 AMD 29000 embedded, using EBMON a29k-none-none
5232 AMD 29000 embedded with COFF a29k-none-coff
5233 AMD 29000 embedded with a.out a29k-none-aout
5235 testsuite/gdb.hp/gdb.threads-hp/ directory
5237 * REMOVED configurations and files
5239 TI TMS320C80 tic80-*-*
5241 PowerPC Solaris powerpcle-*-solaris*
5242 PowerPC Windows NT powerpcle-*-cygwin32
5243 PowerPC Netware powerpc-*-netware*
5244 Harris/CXUX m88k m88*-harris-cxux*
5245 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5246 ns32k-utek-sysv* ns32k-utek-*
5247 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5248 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5249 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5250 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5251 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5253 * Changes to command line processing
5255 The new `--args' feature can be used to specify command-line arguments
5256 for the inferior from gdb's command line.
5258 * Changes to key bindings
5260 There is a new `operate-and-get-next' function bound to `C-o'.
5262 *** Changes in GDB 5.1.1
5264 Fix compile problem on DJGPP.
5266 Fix a problem with floating-point registers on the i386 being
5269 Fix to stop GDB crashing on .debug_str debug info.
5271 Numerous documentation fixes.
5273 Numerous testsuite fixes.
5275 *** Changes in GDB 5.1:
5277 * New native configurations
5279 Alpha FreeBSD alpha*-*-freebsd*
5280 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5281 MIPS GNU/Linux mips*-*-linux*
5282 MIPS SGI Irix 6.x mips*-sgi-irix6*
5283 ia64 AIX ia64-*-aix*
5284 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5288 Motorola 68HC11 and 68HC12 m68hc11-elf
5290 UltraSparc running GNU/Linux sparc64-*-linux*
5292 * OBSOLETE configurations and files
5294 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5295 Harris/CXUX m88k m88*-harris-cxux*
5296 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5297 ns32k-utek-sysv* ns32k-utek-*
5298 TI TMS320C80 tic80-*-*
5300 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5301 PowerPC Solaris powerpcle-*-solaris*
5302 PowerPC Windows NT powerpcle-*-cygwin32
5303 PowerPC Netware powerpc-*-netware*
5304 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5305 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5306 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5307 Apple Macintosh (MPW) host N/A
5309 stuff.c (Program to stuff files into a specially prepared space in kdb)
5310 kdb-start.c (Main loop for the standalone kernel debugger)
5312 Configurations that have been declared obsolete in this release have
5313 been commented out. Unless there is activity to revive these
5314 configurations, the next release of GDB will have their sources
5315 permanently REMOVED.
5317 * REMOVED configurations and files
5319 Altos 3068 m68*-altos-*
5320 Convex c1-*-*, c2-*-*
5322 ARM RISCix arm-*-* (as host)
5326 * GDB has been converted to ISO C.
5328 GDB's source code has been converted to ISO C. In particular, the
5329 sources are fully protoized, and rely on standard headers being
5334 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5336 * The MI enabled by default.
5338 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5339 revised and enabled by default. Packages which use GDB as a debugging
5340 engine behind a UI or another front end are encouraged to switch to
5341 using the GDB/MI interface, instead of the old annotations interface
5342 which is now deprecated.
5344 * Support for debugging Pascal programs.
5346 GDB now includes support for debugging Pascal programs. The following
5347 main features are supported:
5349 - Pascal-specific data types such as sets;
5351 - automatic recognition of Pascal sources based on file-name
5354 - Pascal-style display of data types, variables, and functions;
5356 - a Pascal expression parser.
5358 However, some important features are not yet supported.
5360 - Pascal string operations are not supported at all;
5362 - there are some problems with boolean types;
5364 - Pascal type hexadecimal constants are not supported
5365 because they conflict with the internal variables format;
5367 - support for Pascal objects and classes is not full yet;
5369 - unlike Pascal, GDB is case-sensitive for symbol names.
5371 * Changes in completion.
5373 Commands such as `shell', `run' and `set args', which pass arguments
5374 to inferior programs, now complete on file names, similar to what
5375 users expect at the shell prompt.
5377 Commands which accept locations, such as `disassemble', `print',
5378 `breakpoint', `until', etc. now complete on filenames as well as
5379 program symbols. Thus, if you type "break foob TAB", and the source
5380 files linked into the programs include `foobar.c', that file name will
5381 be one of the candidates for completion. However, file names are not
5382 considered for completion after you typed a colon that delimits a file
5383 name from a name of a function in that file, as in "break foo.c:bar".
5385 `set demangle-style' completes on available demangling styles.
5387 * New platform-independent commands:
5389 It is now possible to define a post-hook for a command as well as a
5390 hook that runs before the command. For more details, see the
5391 documentation of `hookpost' in the GDB manual.
5393 * Changes in GNU/Linux native debugging.
5395 Support for debugging multi-threaded programs has been completely
5396 revised for all platforms except m68k and sparc. You can now debug as
5397 many threads as your system allows you to have.
5399 Attach/detach is supported for multi-threaded programs.
5401 Support for SSE registers was added for x86. This doesn't work for
5402 multi-threaded programs though.
5404 * Changes in MIPS configurations.
5406 Multi-arch support is enabled for all MIPS configurations.
5408 GDB can now be built as native debugger on SGI Irix 6.x systems for
5409 debugging n32 executables. (Debugging 64-bit executables is not yet
5412 * Unified support for hardware watchpoints in all x86 configurations.
5414 Most (if not all) native x86 configurations support hardware-assisted
5415 breakpoints and watchpoints in a unified manner. This support
5416 implements debug register sharing between watchpoints, which allows to
5417 put a virtually infinite number of watchpoints on the same address,
5418 and also supports watching regions up to 16 bytes with several debug
5421 The new maintenance command `maintenance show-debug-regs' toggles
5422 debugging print-outs in functions that insert, remove, and test
5423 watchpoints and hardware breakpoints.
5425 * Changes in the DJGPP native configuration.
5427 New command ``info dos sysinfo'' displays assorted information about
5428 the CPU, OS, memory, and DPMI server.
5430 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5431 display information about segment descriptors stored in GDT, LDT, and
5434 New commands ``info dos pde'' and ``info dos pte'' display entries
5435 from Page Directory and Page Tables (for now works with CWSDPMI only).
5436 New command ``info dos address-pte'' displays the Page Table entry for
5437 a given linear address.
5439 GDB can now pass command lines longer than 126 characters to the
5440 program being debugged (requires an update to the libdbg.a library
5441 which is part of the DJGPP development kit).
5443 DWARF2 debug info is now supported.
5445 It is now possible to `step' and `next' through calls to `longjmp'.
5447 * Changes in documentation.
5449 All GDB documentation was converted to GFDL, the GNU Free
5450 Documentation License.
5452 Tracepoints-related commands are now fully documented in the GDB
5455 TUI, the Text-mode User Interface, is now documented in the manual.
5457 Tracepoints-related commands are now fully documented in the GDB
5460 The "GDB Internals" manual now has an index. It also includes
5461 documentation of `ui_out' functions, GDB coding standards, x86
5462 hardware watchpoints, and memory region attributes.
5464 * GDB's version number moved to ``version.in''
5466 The Makefile variable VERSION has been replaced by the file
5467 ``version.in''. People creating GDB distributions should update the
5468 contents of this file.
5472 GUD support is now a standard part of the EMACS distribution.
5474 *** Changes in GDB 5.0:
5476 * Improved support for debugging FP programs on x86 targets
5478 Unified and much-improved support for debugging floating-point
5479 programs on all x86 targets. In particular, ``info float'' now
5480 displays the FP registers in the same format on all x86 targets, with
5481 greater level of detail.
5483 * Improvements and bugfixes in hardware-assisted watchpoints
5485 It is now possible to watch array elements, struct members, and
5486 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5487 on x86 targets no longer erroneously trigger when the address is
5490 * Improvements in the native DJGPP version of GDB
5492 The distribution now includes all the scripts and auxiliary files
5493 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5494 machines ``out of the box''.
5496 The DJGPP version can now debug programs that use signals. It is
5497 possible to catch signals that happened in the debuggee, deliver
5498 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5499 would kill the program being debugged.) Programs that hook hardware
5500 interrupts (keyboard, timer, etc.) can also be debugged.
5502 It is now possible to debug DJGPP programs that redirect their
5503 standard handles or switch them to raw (as opposed to cooked) mode, or
5504 even close them. The command ``run < foo > bar'' works as expected,
5505 and ``info terminal'' reports useful information about the debuggee's
5506 terminal, including raw/cooked mode, redirection, etc.
5508 The DJGPP version now uses termios functions for console I/O, which
5509 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5512 DOS-style file names with drive letters are now fully supported by
5515 It is now possible to debug DJGPP programs that switch their working
5516 directory. It is also possible to rerun the debuggee any number of
5517 times without restarting GDB; thus, you can use the same setup,
5518 breakpoints, etc. for many debugging sessions.
5520 * New native configurations
5522 ARM GNU/Linux arm*-*-linux*
5523 PowerPC GNU/Linux powerpc-*-linux*
5527 Motorola MCore mcore-*-*
5528 x86 VxWorks i[3456]86-*-vxworks*
5529 PowerPC VxWorks powerpc-*-vxworks*
5530 TI TMS320C80 tic80-*-*
5532 * OBSOLETE configurations
5534 Altos 3068 m68*-altos-*
5535 Convex c1-*-*, c2-*-*
5537 ARM RISCix arm-*-* (as host)
5540 Configurations that have been declared obsolete will be commented out,
5541 but the code will be left in place. If there is no activity to revive
5542 these configurations before the next release of GDB, the sources will
5543 be permanently REMOVED.
5545 * Gould support removed
5547 Support for the Gould PowerNode and NP1 has been removed.
5549 * New features for SVR4
5551 On SVR4 native platforms (such as Solaris), if you attach to a process
5552 without first loading a symbol file, GDB will now attempt to locate and
5553 load symbols from the running process's executable file.
5555 * Many C++ enhancements
5557 C++ support has been greatly improved. Overload resolution now works properly
5558 in almost all cases. RTTI support is on the way.
5560 * Remote targets can connect to a sub-program
5562 A popen(3) style serial-device has been added. This device starts a
5563 sub-process (such as a stand-alone simulator) and then communicates
5564 with that. The sub-program to run is specified using the syntax
5565 ``|<program> <args>'' vis:
5567 (gdb) set remotedebug 1
5568 (gdb) target extended-remote |mn10300-elf-sim program-args
5570 * MIPS 64 remote protocol
5572 A long standing bug in the mips64 remote protocol where by GDB
5573 expected certain 32 bit registers (ex SR) to be transfered as 32
5574 instead of 64 bits has been fixed.
5576 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5577 added to provide backward compatibility with older versions of GDB.
5579 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5581 The command ``set remotebinarydownload'' command has been replaced by
5582 ``set remote X-packet''. Other commands in ``set remote'' family
5583 include ``set remote P-packet''.
5585 * Breakpoint commands accept ranges.
5587 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5588 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5589 ``tracepoint passcount'' also accepts a range of tracepoints.
5591 * ``apropos'' command added.
5593 The ``apropos'' command searches through command names and
5594 documentation strings, printing out matches, making it much easier to
5595 try to find a command that does what you are looking for.
5599 A new machine oriented interface (MI) has been added to GDB. This
5600 interface is designed for debug environments running GDB as a separate
5601 process. This is part of the long term libGDB project. See the
5602 "GDB/MI" chapter of the GDB manual for further information. It can be
5603 enabled by configuring with:
5605 .../configure --enable-gdbmi
5607 *** Changes in GDB-4.18:
5609 * New native configurations
5611 HP-UX 10.20 hppa*-*-hpux10.20
5612 HP-UX 11.x hppa*-*-hpux11.0*
5613 M68K GNU/Linux m68*-*-linux*
5617 Fujitsu FR30 fr30-*-elf*
5618 Intel StrongARM strongarm-*-*
5619 Mitsubishi D30V d30v-*-*
5621 * OBSOLETE configurations
5623 Gould PowerNode, NP1 np1-*-*, pn-*-*
5625 Configurations that have been declared obsolete will be commented out,
5626 but the code will be left in place. If there is no activity to revive
5627 these configurations before the next release of GDB, the sources will
5628 be permanently REMOVED.
5632 As a compatibility experiment, GDB's source files buildsym.h and
5633 buildsym.c have been converted to pure standard C, no longer
5634 containing any K&R compatibility code. We believe that all systems in
5635 use today either come with a standard C compiler, or have a GCC port
5636 available. If this is not true, please report the affected
5637 configuration to bug-gdb@gnu.org immediately. See the README file for
5638 information about getting a standard C compiler if you don't have one
5643 GDB now uses readline 2.2.
5645 * set extension-language
5647 You can now control the mapping between filename extensions and source
5648 languages by using the `set extension-language' command. For instance,
5649 you can ask GDB to treat .c files as C++ by saying
5650 set extension-language .c c++
5651 The command `info extensions' lists all of the recognized extensions
5652 and their associated languages.
5654 * Setting processor type for PowerPC and RS/6000
5656 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5657 you can use the `set processor' command to specify what variant of the
5658 PowerPC family you are debugging. The command
5662 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5663 following PowerPC and RS6000 variants:
5665 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5666 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5668 403GC IBM PowerPC 403GC
5669 505 Motorola PowerPC 505
5670 860 Motorola PowerPC 860 or 850
5671 601 Motorola PowerPC 601
5672 602 Motorola PowerPC 602
5673 603 Motorola/IBM PowerPC 603 or 603e
5674 604 Motorola PowerPC 604 or 604e
5675 750 Motorola/IBM PowerPC 750 or 750
5677 At the moment, this command just tells GDB what to name the
5678 special-purpose processor registers. Since almost all the affected
5679 registers are inaccessible to user-level programs, this command is
5680 only useful for remote debugging in its present form.
5684 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5685 more extensive support for HP-UX. Added features include shared
5686 library support, kernel threads and hardware watchpoints for 11.00,
5687 support for HP's ANSI C and C++ compilers, and a compatibility mode
5688 for xdb and dbx commands.
5692 HP's donation includes the new concept of catchpoints, which is a
5693 generalization of the old catch command. On HP-UX, it is now possible
5694 to catch exec, fork, and vfork, as well as library loading.
5696 This means that the existing catch command has changed; its first
5697 argument now specifies the type of catch to be set up. See the
5698 output of "help catch" for a list of catchpoint types.
5700 * Debugging across forks
5702 On HP-UX, you can choose which process to debug when a fork() happens
5707 HP has donated a curses-based terminal user interface (TUI). To get
5708 it, build with --enable-tui. Although this can be enabled for any
5709 configuration, at present it only works for native HP debugging.
5711 * GDB remote protocol additions
5713 A new protocol packet 'X' that writes binary data is now available.
5714 Default behavior is to try 'X', then drop back to 'M' if the stub
5715 fails to respond. The settable variable `remotebinarydownload'
5716 allows explicit control over the use of 'X'.
5718 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5719 full 64-bit address. The command
5721 set remoteaddresssize 32
5723 can be used to revert to the old behaviour. For existing remote stubs
5724 the change should not be noticed, as the additional address information
5727 In order to assist in debugging stubs, you may use the maintenance
5728 command `packet' to send any text string to the stub. For instance,
5730 maint packet heythere
5732 sends the packet "$heythere#<checksum>". Note that it is very easy to
5733 disrupt a debugging session by sending the wrong packet at the wrong
5736 The compare-sections command allows you to compare section data on the
5737 target to what is in the executable file without uploading or
5738 downloading, by comparing CRC checksums.
5740 * Tracing can collect general expressions
5742 You may now collect general expressions at tracepoints. This requires
5743 further additions to the target-side stub; see tracepoint.c and
5744 doc/agentexpr.texi for further details.
5746 * mask-address variable for Mips
5748 For Mips targets, you may control the zeroing of the upper 32 bits of
5749 a 64-bit address by entering `set mask-address on'. This is mainly
5750 of interest to users of embedded R4xxx and R5xxx processors.
5752 * Higher serial baud rates
5754 GDB's serial code now allows you to specify baud rates 57600, 115200,
5755 230400, and 460800 baud. (Note that your host system may not be able
5756 to achieve all of these rates.)
5760 The i960 configuration now includes an initial implementation of a
5761 builtin simulator, contributed by Jim Wilson.
5764 *** Changes in GDB-4.17:
5766 * New native configurations
5768 Alpha GNU/Linux alpha*-*-linux*
5769 Unixware 2.x i[3456]86-unixware2*
5770 Irix 6.x mips*-sgi-irix6*
5771 PowerPC GNU/Linux powerpc-*-linux*
5772 PowerPC Solaris powerpcle-*-solaris*
5773 Sparc GNU/Linux sparc-*-linux*
5774 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5778 Argonaut Risc Chip (ARC) arc-*-*
5779 Hitachi H8/300S h8300*-*-*
5780 Matsushita MN10200 w/simulator mn10200-*-*
5781 Matsushita MN10300 w/simulator mn10300-*-*
5782 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5783 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5784 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5785 Mitsubishi D10V w/simulator d10v-*-*
5786 Mitsubishi M32R/D w/simulator m32r-*-elf*
5787 Tsqware Sparclet sparclet-*-*
5788 NEC V850 w/simulator v850-*-*
5790 * New debugging protocols
5792 ARM with RDI protocol arm*-*-*
5793 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5794 DDB and LSI variants of PMON protocol mips*-*-*
5795 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5796 PowerPC with SDS protocol powerpc{,le}-*-eabi
5797 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5801 All configurations can now understand and use the DWARF 2 debugging
5802 format. The choice is automatic, if the symbol file contains DWARF 2
5807 GDB now includes basic Java language support. This support is
5808 only useful with Java compilers that produce native machine code.
5810 * solib-absolute-prefix and solib-search-path
5812 For SunOS and SVR4 shared libraries, you may now set the prefix for
5813 loading absolute shared library symbol files, and the search path for
5814 locating non-absolute shared library symbol files.
5816 * Live range splitting
5818 GDB can now effectively debug code for which GCC has performed live
5819 range splitting as part of its optimization. See gdb/doc/LRS for
5820 more details on the expected format of the stabs information.
5824 GDB's support for the GNU Hurd, including thread debugging, has been
5825 updated to work with current versions of the Hurd.
5829 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5830 instruction set. ARM GDB automatically detects when Thumb
5831 instructions are in use, and adjusts disassembly and backtracing
5836 GDB's MIPS target configurations now handle the MIP16 16-bit
5841 GDB now includes support for overlays; if an executable has been
5842 linked such that multiple sections are based at the same address, GDB
5843 will decide which section to use for symbolic info. You can choose to
5844 control the decision manually, using overlay commands, or implement
5845 additional target-side support and use "overlay load-target" to bring
5846 in the overlay mapping. Do "help overlay" for more detail.
5850 The command "info symbol <address>" displays information about
5851 the symbol at the specified address.
5855 The standard remote protocol now includes an extension that allows
5856 asynchronous collection and display of trace data. This requires
5857 extensive support in the target-side debugging stub. Tracing mode
5858 includes a new interaction mode in GDB and new commands: see the
5859 file tracepoint.c for more details.
5863 Configurations for embedded MIPS now include a simulator contributed
5864 by Cygnus Solutions. The simulator supports the instruction sets
5865 of most MIPS variants.
5869 Sparc configurations may now include the ERC32 simulator contributed
5870 by the European Space Agency. The simulator is not built into
5871 Sparc targets by default; configure with --enable-sim to include it.
5875 For target configurations that may include multiple variants of a
5876 basic architecture (such as MIPS and SH), you may now set the
5877 architecture explicitly. "set arch" sets, "info arch" lists
5878 the possible architectures.
5880 *** Changes in GDB-4.16:
5882 * New native configurations
5884 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5885 M68K NetBSD m68k-*-netbsd*
5886 PowerPC AIX 4.x powerpc-*-aix*
5887 PowerPC MacOS powerpc-*-macos*
5888 PowerPC Windows NT powerpcle-*-cygwin32
5889 RS/6000 AIX 4.x rs6000-*-aix4*
5893 ARM with RDP protocol arm-*-*
5894 I960 with MON960 i960-*-coff
5895 MIPS VxWorks mips*-*-vxworks*
5896 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5897 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5899 Matra Sparclet sparclet-*-*
5903 The powerpc-eabi configuration now includes the PSIM simulator,
5904 contributed by Andrew Cagney, with assistance from Mike Meissner.
5905 PSIM is a very elaborate model of the PowerPC, including not only
5906 basic instruction set execution, but also details of execution unit
5907 performance and I/O hardware. See sim/ppc/README for more details.
5911 GDB now works with Solaris 2.5.
5913 * Windows 95/NT native
5915 GDB will now work as a native debugger on Windows 95 and Windows NT.
5916 To build it from source, you must use the "gnu-win32" environment,
5917 which uses a DLL to emulate enough of Unix to run the GNU tools.
5918 Further information, binaries, and sources are available at
5919 ftp.cygnus.com, under pub/gnu-win32.
5921 * dont-repeat command
5923 If a user-defined command includes the command `dont-repeat', then the
5924 command will not be repeated if the user just types return. This is
5925 useful if the command is time-consuming to run, so that accidental
5926 extra keystrokes don't run the same command many times.
5928 * Send break instead of ^C
5930 The standard remote protocol now includes an option to send a break
5931 rather than a ^C to the target in order to interrupt it. By default,
5932 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5934 * Remote protocol timeout
5936 The standard remote protocol includes a new variable `remotetimeout'
5937 that allows you to set the number of seconds before GDB gives up trying
5938 to read from the target. The default value is 2.
5940 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5942 By default GDB will automatically keep track of objects as they are
5943 loaded and unloaded by the dynamic linker. By using the command `set
5944 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5945 when shared library events occur, thus allowing you to set breakpoints
5946 in shared libraries which are explicitly loaded by the inferior.
5948 Note this feature does not work on hpux8. On hpux9 you must link
5949 /usr/lib/end.o into your program. This feature should work
5950 automatically on hpux10.
5952 * Irix 5.x hardware watchpoint support
5954 Irix 5 configurations now support the use of hardware watchpoints.
5956 * Mips protocol "SYN garbage limit"
5958 When debugging a Mips target using the `target mips' protocol, you
5959 may set the number of characters that GDB will ignore by setting
5960 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5961 every character. The default value is 1050.
5963 * Recording and replaying remote debug sessions
5965 If you set `remotelogfile' to the name of a file, gdb will write to it
5966 a recording of a remote debug session. This recording may then be
5967 replayed back to gdb using "gdbreplay". See gdbserver/README for
5968 details. This is useful when you have a problem with GDB while doing
5969 remote debugging; you can make a recording of the session and send it
5970 to someone else, who can then recreate the problem.
5972 * Speedups for remote debugging
5974 GDB includes speedups for downloading and stepping MIPS systems using
5975 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5976 and more efficient S-record downloading.
5978 * Memory use reductions and statistics collection
5980 GDB now uses less memory and reports statistics about memory usage.
5981 Try the `maint print statistics' command, for example.
5983 *** Changes in GDB-4.15:
5985 * Psymtabs for XCOFF
5987 The symbol reader for AIX GDB now uses partial symbol tables. This
5988 can greatly improve startup time, especially for large executables.
5990 * Remote targets use caching
5992 Remote targets now use a data cache to speed up communication with the
5993 remote side. The data cache could lead to incorrect results because
5994 it doesn't know about volatile variables, thus making it impossible to
5995 debug targets which use memory mapped I/O devices. `set remotecache
5996 off' turns the the data cache off.
5998 * Remote targets may have threads
6000 The standard remote protocol now includes support for multiple threads
6001 in the target system, using new protocol commands 'H' and 'T'. See
6002 gdb/remote.c for details.
6006 If GDB is configured with `--enable-netrom', then it will include
6007 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6008 acts as though it is a bank of ROM on the target board, but you can
6009 write into it over the network. GDB's support consists only of
6010 support for fast loading into the emulated ROM; to debug, you must use
6011 another protocol, such as standard remote protocol. The usual
6012 sequence is something like
6014 target nrom <netrom-hostname>
6016 target remote <netrom-hostname>:1235
6020 GDB now includes support for the Apple Macintosh, as a host only. It
6021 may be run as either an MPW tool or as a standalone application, and
6022 it can debug through the serial port. All the usual GDB commands are
6023 available, but to the target command, you must supply "serial" as the
6024 device type instead of "/dev/ttyXX". See mpw-README in the main
6025 directory for more information on how to build. The MPW configuration
6026 scripts */mpw-config.in support only a few targets, and only the
6027 mips-idt-ecoff target has been tested.
6031 GDB configuration now uses autoconf. This is not user-visible,
6032 but does simplify configuration and building.
6036 GDB now supports hpux10.
6038 *** Changes in GDB-4.14:
6040 * New native configurations
6042 x86 FreeBSD i[345]86-*-freebsd
6043 x86 NetBSD i[345]86-*-netbsd
6044 NS32k NetBSD ns32k-*-netbsd
6045 Sparc NetBSD sparc-*-netbsd
6049 A29K VxWorks a29k-*-vxworks
6050 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6051 CPU32 EST-300 emulator m68*-*-est*
6052 PowerPC ELF powerpc-*-elf
6055 * Alpha OSF/1 support for procfs
6057 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6058 possible to attach to running processes. As the mounting of the /proc
6059 filesystem is optional on the Alpha, GDB automatically determines
6060 the availability of /proc during startup. This can lead to problems
6061 if /proc is unmounted after GDB has been started.
6063 * Arguments to user-defined commands
6065 User commands may accept up to 10 arguments separated by whitespace.
6066 Arguments are accessed within the user command via $arg0..$arg9. A
6069 print $arg0 + $arg1 + $arg2
6071 To execute the command use:
6074 Defines the command "adder" which prints the sum of its three arguments.
6075 Note the arguments are text substitutions, so they may reference variables,
6076 use complex expressions, or even perform inferior function calls.
6078 * New `if' and `while' commands
6080 This makes it possible to write more sophisticated user-defined
6081 commands. Both commands take a single argument, which is the
6082 expression to evaluate, and must be followed by the commands to
6083 execute, one per line, if the expression is nonzero, the list being
6084 terminated by the word `end'. The `if' command list may include an
6085 `else' word, which causes the following commands to be executed only
6086 if the expression is zero.
6088 * Fortran source language mode
6090 GDB now includes partial support for Fortran 77. It will recognize
6091 Fortran programs and can evaluate a subset of Fortran expressions, but
6092 variables and functions may not be handled correctly. GDB will work
6093 with G77, but does not yet know much about symbols emitted by other
6096 * Better HPUX support
6098 Most debugging facilities now work on dynamic executables for HPPAs
6099 running hpux9 or later. You can attach to running dynamically linked
6100 processes, but by default the dynamic libraries will be read-only, so
6101 for instance you won't be able to put breakpoints in them. To change
6102 that behavior do the following before running the program:
6108 This will cause the libraries to be mapped private and read-write.
6109 To revert to the normal behavior, do this:
6115 You cannot set breakpoints or examine data in the library until after
6116 the library is loaded if the function/data symbols do not have
6119 GDB can now also read debug symbols produced by the HP C compiler on
6120 HPPAs (sorry, no C++, Fortran or 68k support).
6122 * Target byte order now dynamically selectable
6124 You can choose which byte order to use with a target system, via the
6125 commands "set endian big" and "set endian little", and you can see the
6126 current setting by using "show endian". You can also give the command
6127 "set endian auto", in which case GDB will use the byte order
6128 associated with the executable. Currently, only embedded MIPS
6129 configurations support dynamic selection of target byte order.
6131 * New DOS host serial code
6133 This version uses DPMI interrupts to handle buffered I/O, so you
6134 no longer need to run asynctsr when debugging boards connected to
6137 *** Changes in GDB-4.13:
6139 * New "complete" command
6141 This lists all the possible completions for the rest of the line, if it
6142 were to be given as a command itself. This is intended for use by emacs.
6144 * Trailing space optional in prompt
6146 "set prompt" no longer adds a space for you after the prompt you set. This
6147 allows you to set a prompt which ends in a space or one that does not.
6149 * Breakpoint hit counts
6151 "info break" now displays a count of the number of times the breakpoint
6152 has been hit. This is especially useful in conjunction with "ignore"; you
6153 can ignore a large number of breakpoint hits, look at the breakpoint info
6154 to see how many times the breakpoint was hit, then run again, ignoring one
6155 less than that number, and this will get you quickly to the last hit of
6158 * Ability to stop printing at NULL character
6160 "set print null-stop" will cause GDB to stop printing the characters of
6161 an array when the first NULL is encountered. This is useful when large
6162 arrays actually contain only short strings.
6164 * Shared library breakpoints
6166 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6167 breakpoints in shared libraries before the executable is run.
6169 * Hardware watchpoints
6171 There is a new hardware breakpoint for the watch command for sparclite
6172 targets. See gdb/sparclite/hw_breakpoint.note.
6174 Hardware watchpoints are also now supported under GNU/Linux.
6178 Annotations have been added. These are for use with graphical interfaces,
6179 and are still experimental. Currently only gdba.el uses these.
6181 * Improved Irix 5 support
6183 GDB now works properly with Irix 5.2.
6185 * Improved HPPA support
6187 GDB now works properly with the latest GCC and GAS.
6189 * New native configurations
6191 Sequent PTX4 i[34]86-sequent-ptx4
6192 HPPA running OSF/1 hppa*-*-osf*
6193 Atari TT running SVR4 m68*-*-sysv4*
6194 RS/6000 LynxOS rs6000-*-lynxos*
6198 OS/9000 i[34]86-*-os9k
6199 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6202 * Hitachi SH7000 and E7000-PC ICE support
6204 There is now support for communicating with the Hitachi E7000-PC ICE.
6205 This is available automatically when GDB is configured for the SH.
6209 As usual, a variety of small fixes and improvements, both generic
6210 and configuration-specific. See the ChangeLog for more detail.
6212 *** Changes in GDB-4.12:
6214 * Irix 5 is now supported
6218 GDB-4.12 on the HPPA has a number of changes which make it unable
6219 to debug the output from the currently released versions of GCC and
6220 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6221 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6222 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6225 *** Changes in GDB-4.11:
6227 * User visible changes:
6231 The "set remotedebug" option is now consistent between the mips remote
6232 target, remote targets using the gdb-specific protocol, UDI (AMD's
6233 debug protocol for the 29k) and the 88k bug monitor. It is now an
6234 integer specifying a debug level (normally 0 or 1, but 2 means more
6235 debugging info for the mips target).
6237 * DEC Alpha native support
6239 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6240 debug info, but GDB works fairly well with the DEC compiler and should
6241 work with a future GCC release. See the README file for a few
6242 Alpha-specific notes.
6244 * Preliminary thread implementation
6246 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6248 * LynxOS native and target support for 386
6250 This release has been hosted on LynxOS 2.2, and also can be configured
6251 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6254 * Improvements in C++ mangling/demangling.
6256 This release has much better g++ debugging, specifically in name
6257 mangling/demangling, virtual function calls, print virtual table,
6258 call methods, ...etc.
6260 *** Changes in GDB-4.10:
6262 * User visible changes:
6264 Remote debugging using the GDB-specific (`target remote') protocol now
6265 supports the `load' command. This is only useful if you have some
6266 other way of getting the stub to the target system, and you can put it
6267 somewhere in memory where it won't get clobbered by the download.
6269 Filename completion now works.
6271 When run under emacs mode, the "info line" command now causes the
6272 arrow to point to the line specified. Also, "info line" prints
6273 addresses in symbolic form (as well as hex).
6275 All vxworks based targets now support a user settable option, called
6276 vxworks-timeout. This option represents the number of seconds gdb
6277 should wait for responses to rpc's. You might want to use this if
6278 your vxworks target is, perhaps, a slow software simulator or happens
6279 to be on the far side of a thin network line.
6283 This release contains support for using a DEC alpha as a GDB host for
6284 cross debugging. Native alpha debugging is not supported yet.
6287 *** Changes in GDB-4.9:
6291 This is the first GDB release which is accompanied by a matching testsuite.
6292 The testsuite requires installation of dejagnu, which should be available
6293 via ftp from most sites that carry GNU software.
6297 'Cfront' style demangling has had its name changed to 'ARM' style, to
6298 emphasize that it was written from the specifications in the C++ Annotated
6299 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6300 disclaimers, it still generated too much confusion with users attempting to
6301 use gdb with AT&T cfront.
6305 GDB now uses a standard remote interface to a simulator library.
6306 So far, the library contains simulators for the Zilog Z8001/2, the
6307 Hitachi H8/300, H8/500 and Super-H.
6309 * New targets supported
6311 H8/300 simulator h8300-hitachi-hms or h8300hms
6312 H8/500 simulator h8500-hitachi-hms or h8500hms
6313 SH simulator sh-hitachi-hms or sh
6314 Z8000 simulator z8k-zilog-none or z8ksim
6315 IDT MIPS board over serial line mips-idt-ecoff
6317 Cross-debugging to GO32 targets is supported. It requires a custom
6318 version of the i386-stub.c module which is integrated with the
6319 GO32 memory extender.
6321 * New remote protocols
6323 MIPS remote debugging protocol.
6325 * New source languages supported
6327 This version includes preliminary support for Chill, a Pascal like language
6328 used by telecommunications companies. Chill support is also being integrated
6329 into the GNU compiler, but we don't know when it will be publically available.
6332 *** Changes in GDB-4.8:
6334 * HP Precision Architecture supported
6336 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6337 version of this support was available as a set of patches from the
6338 University of Utah. GDB does not support debugging of programs
6339 compiled with the HP compiler, because HP will not document their file
6340 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6341 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6343 Many problems in the preliminary version have been fixed.
6345 * Faster and better demangling
6347 We have improved template demangling and fixed numerous bugs in the GNU style
6348 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6349 character types (wchar_t) are now supported. Demangling of each symbol is now
6350 only done once, and is cached when the symbol table for a file is read in.
6351 This results in a small increase in memory usage for C programs, a moderate
6352 increase in memory usage for C++ programs, and a fantastic speedup in
6355 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6356 from the specifications in the Annotated Reference Manual, which AT&T's
6357 compiler does not actually implement.
6359 * G++ multiple inheritance compiler problem
6361 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6362 inheritance lattices was reworked to properly discover ambiguities. We
6363 recently found an example which causes this new algorithm to fail in a
6364 very subtle way, producing bad debug information for those classes.
6365 The file 'gcc.patch' (in this directory) can be applied to gcc to
6366 circumvent the problem. A future GCC release will contain a complete
6369 The previous G++ debug info problem (mentioned below for the gdb-4.7
6370 release) is fixed in gcc version 2.3.2.
6372 * Improved configure script
6374 The `configure' script will now attempt to guess your system type if
6375 you don't supply a host system type. The old scheme of supplying a
6376 host system triplet is preferable over using this. All the magic is
6377 done in the new `config.guess' script. Examine it for details.
6379 We have also brought our configure script much more in line with the FSF's
6380 version. It now supports the --with-xxx options. In particular,
6381 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6382 The resulting GDB will not be able to read arbitrary object file formats --
6383 only the format ``expected'' to be used on the configured target system.
6384 We hope to make this the default in a future release.
6386 * Documentation improvements
6388 There's new internal documentation on how to modify GDB, and how to
6389 produce clean changes to the code. We implore people to read it
6390 before submitting changes.
6392 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6393 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6394 `info' files are also provided. To build `info' files from scratch,
6395 you will need the latest `makeinfo' release, which will be available in
6396 a future texinfo-X.Y release.
6398 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6399 We're not sure exactly which versions have this problem, but it has
6400 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6401 or better. If that isn't possible, there is a patch in
6402 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6403 around this problem.
6407 GDB now supports array constants that can be used in expressions typed in by
6408 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6409 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6412 The new directory `gdb/sparclite' contains a program that demonstrates
6413 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6415 * New native hosts supported
6417 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6418 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6420 * New targets supported
6422 AMD 29k family via UDI a29k-amd-udi or udi29k
6424 * New file formats supported
6426 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6427 HPUX core files, and SCO 3.2v2 core files.
6431 Attaching to processes now works again; thanks for the many bug reports.
6433 We have also stomped on a bunch of core dumps caused by
6434 printf_filtered("%s") problems.
6436 We eliminated a copyright problem on the rpc and ptrace header files
6437 for VxWorks, which was discovered at the last minute during the 4.7
6438 release. You should now be able to build a VxWorks GDB.
6440 You can now interrupt gdb while an attached process is running. This
6441 will cause the attached process to stop, and give control back to GDB.
6443 We fixed problems caused by using too many file descriptors
6444 for reading symbols from object files and libraries. This was
6445 especially a problem for programs that used many (~100) shared
6448 The `step' command now only enters a subroutine if there is line number
6449 information for the subroutine. Otherwise it acts like the `next'
6450 command. Previously, `step' would enter subroutines if there was
6451 any debugging information about the routine. This avoids problems
6452 when using `cc -g1' on MIPS machines.
6454 * Internal improvements
6456 GDB's internal interfaces have been improved to make it easier to support
6457 debugging of multiple languages in the future.
6459 GDB now uses a common structure for symbol information internally.
6460 Minimal symbols (derived from linkage symbols in object files), partial
6461 symbols (from a quick scan of debug information), and full symbols
6462 contain a common subset of information, making it easier to write
6463 shared code that handles any of them.
6465 * New command line options
6467 We now accept --silent as an alias for --quiet.
6471 The memory-mapped-malloc library is now licensed under the GNU Library
6472 General Public License.
6474 *** Changes in GDB-4.7:
6476 * Host/native/target split
6478 GDB has had some major internal surgery to untangle the support for
6479 hosts and remote targets. Now, when you configure GDB for a remote
6480 target, it will no longer load in all of the support for debugging
6481 local programs on the host. When fully completed and tested, this will
6482 ensure that arbitrary host/target combinations are possible.
6484 The primary conceptual shift is to separate the non-portable code in
6485 GDB into three categories. Host specific code is required any time GDB
6486 is compiled on that host, regardless of the target. Target specific
6487 code relates to the peculiarities of the target, but can be compiled on
6488 any host. Native specific code is everything else: it can only be
6489 built when the host and target are the same system. Child process
6490 handling and core file support are two common `native' examples.
6492 GDB's use of /proc for controlling Unix child processes is now cleaner.
6493 It has been split out into a single module under the `target_ops' vector,
6494 plus two native-dependent functions for each system that uses /proc.
6496 * New hosts supported
6498 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6499 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6500 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6502 * New targets supported
6504 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6505 68030 and CPU32 m68030-*-*, m68332-*-*
6507 * New native hosts supported
6509 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6510 (386bsd is not well tested yet)
6511 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6513 * New file formats supported
6515 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6516 supports reading of `a.out.adobe' object files, which are an a.out
6517 format extended with minimal information about multiple sections.
6521 `show copying' is the same as the old `info copying'.
6522 `show warranty' is the same as `info warrantee'.
6523 These were renamed for consistency. The old commands continue to work.
6525 `info handle' is a new alias for `info signals'.
6527 You can now define pre-command hooks, which attach arbitrary command
6528 scripts to any command. The commands in the hook will be executed
6529 prior to the user's command. You can also create a hook which will be
6530 executed whenever the program stops. See gdb.texinfo.
6534 We now deal with Cfront style name mangling, and can even extract type
6535 info from mangled symbols. GDB can automatically figure out which
6536 symbol mangling style your C++ compiler uses.
6538 Calling of methods and virtual functions has been improved as well.
6542 The crash that occured when debugging Sun Ansi-C compiled binaries is
6543 fixed. This was due to mishandling of the extra N_SO stabs output
6546 We also finally got Ultrix 4.2 running in house, and fixed core file
6547 support, with help from a dozen people on the net.
6549 John M. Farrell discovered that the reason that single-stepping was so
6550 slow on all of the Mips based platforms (primarily SGI and DEC) was
6551 that we were trying to demangle and lookup a symbol used for internal
6552 purposes on every instruction that was being stepped through. Changing
6553 the name of that symbol so that it couldn't be mistaken for a C++
6554 mangled symbol sped things up a great deal.
6556 Rich Pixley sped up symbol lookups in general by getting much smarter
6557 about when C++ symbol mangling is necessary. This should make symbol
6558 completion (TAB on the command line) much faster. It's not as fast as
6559 we'd like, but it's significantly faster than gdb-4.6.
6563 A new user controllable variable 'call_scratch_address' can
6564 specify the location of a scratch area to be used when GDB
6565 calls a function in the target. This is necessary because the
6566 usual method of putting the scratch area on the stack does not work
6567 in systems that have separate instruction and data spaces.
6569 We integrated changes to support the 29k UDI (Universal Debugger
6570 Interface), but discovered at the last minute that we didn't have all
6571 of the appropriate copyright paperwork. We are working with AMD to
6572 resolve this, and hope to have it available soon.
6576 We have sped up the remote serial line protocol, especially for targets
6577 with lots of registers. It now supports a new `expedited status' ('T')
6578 message which can be used in place of the existing 'S' status message.
6579 This allows the remote stub to send only the registers that GDB
6580 needs to make a quick decision about single-stepping or conditional
6581 breakpoints, eliminating the need to fetch the entire register set for
6582 each instruction being stepped through.
6584 The GDB remote serial protocol now implements a write-through cache for
6585 registers, only re-reading the registers if the target has run.
6587 There is also a new remote serial stub for SPARC processors. You can
6588 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6589 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6590 processor with a serial port.
6594 Configure.in files have become much easier to read and modify. A new
6595 `table driven' format makes it more obvious what configurations are
6596 supported, and what files each one uses.
6600 There is a new opcodes library which will eventually contain all of the
6601 disassembly routines and opcode tables. At present, it only contains
6602 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6603 disassembler (binutils/objdump) to share these routines.
6605 The libiberty library is now copylefted under the GNU Library General
6606 Public License. This allows more liberal use, and was done so libg++
6607 can use it. This makes no difference to GDB, since the Library License
6608 grants all the rights from the General Public License.
6612 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6613 reference to the stabs symbol info used by the debugger. It is (as far
6614 as we know) the only published document on this fascinating topic. We
6615 encourage you to read it, compare it to the stabs information on your
6616 system, and send improvements on the document in general (to
6617 bug-gdb@prep.ai.mit.edu).
6619 And, of course, many bugs have been fixed.
6622 *** Changes in GDB-4.6:
6624 * Better support for C++ function names
6626 GDB now accepts as input the "demangled form" of C++ overloaded function
6627 names and member function names, and can do command completion on such names
6628 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6629 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6630 Make use of command completion, it is your friend.
6632 GDB also now accepts a variety of C++ mangled symbol formats. They are
6633 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6634 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6635 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6636 for the list of formats.
6638 * G++ symbol mangling problem
6640 Recent versions of gcc have a bug in how they emit debugging information for
6641 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6642 directory) can be applied to gcc to fix the problem. Alternatively, if you
6643 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6644 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6645 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6648 * New 'maintenance' command
6650 All of the commands related to hacking GDB internals have been moved out of
6651 the main command set, and now live behind the 'maintenance' command. This
6652 can also be abbreviated as 'mt'. The following changes were made:
6654 dump-me -> maintenance dump-me
6655 info all-breakpoints -> maintenance info breakpoints
6656 printmsyms -> maintenance print msyms
6657 printobjfiles -> maintenance print objfiles
6658 printpsyms -> maintenance print psymbols
6659 printsyms -> maintenance print symbols
6661 The following commands are new:
6663 maintenance demangle Call internal GDB demangler routine to
6664 demangle a C++ link name and prints the result.
6665 maintenance print type Print a type chain for a given symbol
6667 * Change to .gdbinit file processing
6669 We now read the $HOME/.gdbinit file before processing the argv arguments
6670 (e.g. reading symbol files or core files). This allows global parameters to
6671 be set, which will apply during the symbol reading. The ./.gdbinit is still
6672 read after argv processing.
6674 * New hosts supported
6676 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6678 GNU/Linux support i386-unknown-linux or linux
6680 We are also including code to support the HP/PA running BSD and HPUX. This
6681 is almost guaranteed not to work, as we didn't have time to test or build it
6682 for this release. We are including it so that the more adventurous (or
6683 masochistic) of you can play with it. We also had major problems with the
6684 fact that the compiler that we got from HP doesn't support the -g option.
6687 * New targets supported
6689 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6691 * More smarts about finding #include files
6693 GDB now remembers the compilation directory for all include files, and for
6694 all files from which C is generated (like yacc and lex sources). This
6695 greatly improves GDB's ability to find yacc/lex sources, and include files,
6696 especially if you are debugging your program from a directory different from
6697 the one that contains your sources.
6699 We also fixed a bug which caused difficulty with listing and setting
6700 breakpoints in include files which contain C code. (In the past, you had to
6701 try twice in order to list an include file that you hadn't looked at before.)
6703 * Interesting infernals change
6705 GDB now deals with arbitrary numbers of sections, where the symbols for each
6706 section must be relocated relative to that section's landing place in the
6707 target's address space. This work was needed to support ELF with embedded
6708 stabs used by Solaris-2.0.
6710 * Bug fixes (of course!)
6712 There have been loads of fixes for the following things:
6713 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6714 i960, stabs, DOS(GO32), procfs, etc...
6716 See the ChangeLog for details.
6718 *** Changes in GDB-4.5:
6720 * New machines supported (host and target)
6722 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6724 SGI Irix-4.x mips-sgi-irix4 or iris4
6726 * New malloc package
6728 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6729 Mmalloc is capable of handling mutiple heaps of memory. It is also
6730 capable of saving a heap to a file, and then mapping it back in later.
6731 This can be used to greatly speedup the startup of GDB by using a
6732 pre-parsed symbol table which lives in a mmalloc managed heap. For
6733 more details, please read mmalloc/mmalloc.texi.
6737 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6738 'help info proc' for details.
6740 * MIPS ecoff symbol table format
6742 The code that reads MIPS symbol table format is now supported on all hosts.
6743 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6746 * File name changes for MS-DOS
6748 Many files in the config directories have been renamed to make it easier to
6749 support GDB on MS-DOSe systems (which have very restrictive file name
6750 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6751 environment) is close to working but has some remaining problems. Note
6752 that debugging of DOS programs is not supported, due to limitations
6753 in the ``operating system'', but it can be used to host cross-debugging.
6755 * Cross byte order fixes
6757 Many fixes have been made to support cross debugging of Sparc and MIPS
6758 targets from hosts whose byte order differs.
6760 * New -mapped and -readnow options
6762 If memory-mapped files are available on your system through the 'mmap'
6763 system call, you can use the -mapped option on the `file' or
6764 `symbol-file' commands to cause GDB to write the symbols from your
6765 program into a reusable file. If the program you are debugging is
6766 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6767 Future GDB debugging sessions will notice the presence of this file,
6768 and will quickly map in symbol information from it, rather than reading
6769 the symbol table from the executable program. Using the '-mapped'
6770 option in a GDB `file' or `symbol-file' command has the same effect as
6771 starting GDB with the '-mapped' command-line option.
6773 You can cause GDB to read the entire symbol table immediately by using
6774 the '-readnow' option with any of the commands that load symbol table
6775 information (or on the GDB command line). This makes the command
6776 slower, but makes future operations faster.
6778 The -mapped and -readnow options are typically combined in order to
6779 build a `fred.syms' file that contains complete symbol information.
6780 A simple GDB invocation to do nothing but build a `.syms' file for future
6783 gdb -batch -nx -mapped -readnow programname
6785 The `.syms' file is specific to the host machine on which GDB is run.
6786 It holds an exact image of GDB's internal symbol table. It cannot be
6787 shared across multiple host platforms.
6789 * longjmp() handling
6791 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6792 siglongjmp() without losing control. This feature has not yet been ported to
6793 all systems. It currently works on many 386 platforms, all MIPS-based
6794 platforms (SGI, DECstation, etc), and Sun3/4.
6798 Preliminary work has been put in to support the new Solaris OS from Sun. At
6799 this time, it can control and debug processes, but it is not capable of
6804 As always, many many bug fixes. The major areas were with g++, and mipsread.
6805 People using the MIPS-based platforms should experience fewer mysterious
6806 crashes and trashed symbol tables.
6808 *** Changes in GDB-4.4:
6810 * New machines supported (host and target)
6812 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6814 BSD Reno on Vax vax-dec-bsd
6815 Ultrix on Vax vax-dec-ultrix
6817 * New machines supported (target)
6819 AMD 29000 embedded, using EBMON a29k-none-none
6823 GDB continues to improve its handling of C++. `References' work better.
6824 The demangler has also been improved, and now deals with symbols mangled as
6825 per the Annotated C++ Reference Guide.
6827 GDB also now handles `stabs' symbol information embedded in MIPS
6828 `ecoff' symbol tables. Since the ecoff format was not easily
6829 extensible to handle new languages such as C++, this appeared to be a
6830 good way to put C++ debugging info into MIPS binaries. This option
6831 will be supported in the GNU C compiler, version 2, when it is
6834 * New features for SVR4
6836 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6837 shared libraries. Debugging dynamically linked programs should present
6838 only minor differences from debugging statically linked programs.
6840 The `info proc' command will print out information about any process
6841 on an SVR4 system (including the one you are debugging). At the moment,
6842 it prints the address mappings of the process.
6844 If you bring up GDB on another SVR4 system, please send mail to
6845 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6847 * Better dynamic linking support in SunOS
6849 Reading symbols from shared libraries which contain debugging symbols
6850 now works properly. However, there remain issues such as automatic
6851 skipping of `transfer vector' code during function calls, which
6852 make it harder to debug code in a shared library, than to debug the
6853 same code linked statically.
6857 GDB is now using the latest `getopt' routines from the FSF. This
6858 version accepts the -- prefix for options with long names. GDB will
6859 continue to accept the old forms (-option and +option) as well.
6860 Various single letter abbreviations for options have been explicity
6861 added to the option table so that they won't get overshadowed in the
6862 future by other options that begin with the same letter.
6866 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6867 Many assorted bugs have been handled. Many more remain to be handled.
6868 See the various ChangeLog files (primarily in gdb and bfd) for details.
6871 *** Changes in GDB-4.3:
6873 * New machines supported (host and target)
6875 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6876 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6877 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6879 * Almost SCO Unix support
6881 We had hoped to support:
6882 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6883 (except for core file support), but we discovered very late in the release
6884 that it has problems with process groups that render gdb unusable. Sorry
6885 about that. I encourage people to fix it and post the fixes.
6887 * Preliminary ELF and DWARF support
6889 GDB can read ELF object files on System V Release 4, and can handle
6890 debugging records for C, in DWARF format, in ELF files. This support
6891 is preliminary. If you bring up GDB on another SVR4 system, please
6892 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6897 GDB now uses the latest `readline' library. One user-visible change
6898 is that two tabs will list possible command completions, which previously
6899 required typing M-? (meta-question mark, or ESC ?).
6903 The `stepi' bug that many of you noticed has been squashed.
6904 Many bugs in C++ have been handled. Many more remain to be handled.
6905 See the various ChangeLog files (primarily in gdb and bfd) for details.
6907 * State of the MIPS world (in case you wondered):
6909 GDB can understand the symbol tables emitted by the compilers
6910 supplied by most vendors of MIPS-based machines, including DEC. These
6911 symbol tables are in a format that essentially nobody else uses.
6913 Some versions of gcc come with an assembler post-processor called
6914 mips-tfile. This program is required if you want to do source-level
6915 debugging of gcc-compiled programs. I believe FSF does not ship
6916 mips-tfile with gcc version 1, but it will eventually come with gcc
6919 Debugging of g++ output remains a problem. g++ version 1.xx does not
6920 really support it at all. (If you're lucky, you should be able to get
6921 line numbers and stack traces to work, but no parameters or local
6922 variables.) With some work it should be possible to improve the
6925 When gcc version 2 is released, you will have somewhat better luck.
6926 However, even then you will get confusing results for inheritance and
6929 We will eventually provide full debugging of g++ output on
6930 DECstations. This will probably involve some kind of stabs-in-ecoff
6931 encapulation, but the details have not been worked out yet.
6934 *** Changes in GDB-4.2:
6936 * Improved configuration
6938 Only one copy of `configure' exists now, and it is not self-modifying.
6939 Porting BFD is simpler.
6943 The `step' and `next' commands now only stop at the first instruction
6944 of a source line. This prevents the multiple stops that used to occur
6945 in switch statements, for-loops, etc. `Step' continues to stop if a
6946 function that has debugging information is called within the line.
6950 Lots of small bugs fixed. More remain.
6952 * New host supported (not target)
6954 Intel 386 PC clone running Mach i386-none-mach
6957 *** Changes in GDB-4.1:
6959 * Multiple source language support
6961 GDB now has internal scaffolding to handle several source languages.
6962 It determines the type of each source file from its filename extension,
6963 and will switch expression parsing and number formatting to match the
6964 language of the function in the currently selected stack frame.
6965 You can also specifically set the language to be used, with
6966 `set language c' or `set language modula-2'.
6970 GDB now has preliminary support for the GNU Modula-2 compiler,
6971 currently under development at the State University of New York at
6972 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6973 continue through the fall of 1991 and into 1992.
6975 Other Modula-2 compilers are currently not supported, and attempting to
6976 debug programs compiled with them will likely result in an error as the
6977 symbol table is read. Feel free to work on it, though!
6979 There are hooks in GDB for strict type checking and range checking,
6980 in the `Modula-2 philosophy', but they do not currently work.
6984 GDB can now write to executable and core files (e.g. patch
6985 a variable's value). You must turn this switch on, specify
6986 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6987 by assigning a new value to a variable. Modifications take
6990 * Automatic SunOS shared library reading
6992 When you run your program, GDB automatically determines where its
6993 shared libraries (if any) have been loaded, and reads their symbols.
6994 The `share' command is no longer needed. This also works when
6995 examining core files.
6999 You can specify the number of lines that the `list' command shows.
7002 * New machines supported (host and target)
7004 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7005 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7006 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7008 * New hosts supported (not targets)
7010 IBM RT/PC: romp-ibm-aix or rtpc
7012 * New targets supported (not hosts)
7014 AMD 29000 embedded with COFF a29k-none-coff
7015 AMD 29000 embedded with a.out a29k-none-aout
7016 Ultracomputer remote kernel debug a29k-nyu-kern
7018 * New remote interfaces
7024 *** Changes in GDB-4.0:
7028 Wide output is wrapped at good places to make the output more readable.
7030 Gdb now supports cross-debugging from a host machine of one type to a
7031 target machine of another type. Communication with the target system
7032 is over serial lines. The ``target'' command handles connecting to the
7033 remote system; the ``load'' command will download a program into the
7034 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7035 also supports debugging of realtime processes running under VxWorks,
7036 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7037 stub on the target system.
7039 New CPUs supported include the AMD 29000 and Intel 960.
7041 GDB now reads object files and symbol tables via a ``binary file''
7042 library, which allows a single copy of GDB to debug programs of multiple
7043 object file types such as a.out and coff.
7045 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7046 refcard.dvi and refcard.ps are available to format it).
7049 * Control-Variable user interface simplified
7051 All variables that control the operation of the debugger can be set
7052 by the ``set'' command, and displayed by the ``show'' command.
7054 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7055 ``Show prompt'' produces the response:
7056 Gdb's prompt is new-gdb=>.
7058 What follows are the NEW set commands. The command ``help set'' will
7059 print a complete list of old and new set commands. ``help set FOO''
7060 will give a longer description of the variable FOO. ``show'' will show
7061 all of the variable descriptions and their current settings.
7063 confirm on/off: Enables warning questions for operations that are
7064 hard to recover from, e.g. rerunning the program while
7065 it is already running. Default is ON.
7067 editing on/off: Enables EMACS style command line editing
7068 of input. Previous lines can be recalled with
7069 control-P, the current line can be edited with control-B,
7070 you can search for commands with control-R, etc.
7073 history filename NAME: NAME is where the gdb command history
7074 will be stored. The default is .gdb_history,
7075 or the value of the environment variable
7078 history size N: The size, in commands, of the command history. The
7079 default is 256, or the value of the environment variable
7082 history save on/off: If this value is set to ON, the history file will
7083 be saved after exiting gdb. If set to OFF, the
7084 file will not be saved. The default is OFF.
7086 history expansion on/off: If this value is set to ON, then csh-like
7087 history expansion will be performed on
7088 command line input. The default is OFF.
7090 radix N: Sets the default radix for input and output. It can be set
7091 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7092 in the current radix, so "set radix 10" is always a no-op.
7094 height N: This integer value is the number of lines on a page. Default
7095 is 24, the current `stty rows'' setting, or the ``li#''
7096 setting from the termcap entry matching the environment
7099 width N: This integer value is the number of characters on a line.
7100 Default is 80, the current `stty cols'' setting, or the ``co#''
7101 setting from the termcap entry matching the environment
7104 Note: ``set screensize'' is obsolete. Use ``set height'' and
7105 ``set width'' instead.
7107 print address on/off: Print memory addresses in various command displays,
7108 such as stack traces and structure values. Gdb looks
7109 more ``symbolic'' if you turn this off; it looks more
7110 ``machine level'' with it on. Default is ON.
7112 print array on/off: Prettyprint arrays. New convenient format! Default
7115 print demangle on/off: Print C++ symbols in "source" form if on,
7118 print asm-demangle on/off: Same, for assembler level printouts
7121 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7124 * Support for Epoch Environment.
7126 The epoch environment is a version of Emacs v18 with windowing. One
7127 new command, ``inspect'', is identical to ``print'', except that if you
7128 are running in the epoch environment, the value is printed in its own
7132 * Support for Shared Libraries
7134 GDB can now debug programs and core files that use SunOS shared libraries.
7135 Symbols from a shared library cannot be referenced
7136 before the shared library has been linked with the program (this
7137 happens after you type ``run'' and before the function main() is entered).
7138 At any time after this linking (including when examining core files
7139 from dynamically linked programs), gdb reads the symbols from each
7140 shared library when you type the ``sharedlibrary'' command.
7141 It can be abbreviated ``share''.
7143 sharedlibrary REGEXP: Load shared object library symbols for files
7144 matching a unix regular expression. No argument
7145 indicates to load symbols for all shared libraries.
7147 info sharedlibrary: Status of loaded shared libraries.
7152 A watchpoint stops execution of a program whenever the value of an
7153 expression changes. Checking for this slows down execution
7154 tremendously whenever you are in the scope of the expression, but is
7155 quite useful for catching tough ``bit-spreader'' or pointer misuse
7156 problems. Some machines such as the 386 have hardware for doing this
7157 more quickly, and future versions of gdb will use this hardware.
7159 watch EXP: Set a watchpoint (breakpoint) for an expression.
7161 info watchpoints: Information about your watchpoints.
7163 delete N: Deletes watchpoint number N (same as breakpoints).
7164 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7165 enable N: Re-enables watchpoint number N (same as breakpoints).
7168 * C++ multiple inheritance
7170 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7173 * C++ exception handling
7175 Gdb now supports limited C++ exception handling. Besides the existing
7176 ability to breakpoint on an exception handler, gdb can breakpoint on
7177 the raising of an exception (before the stack is peeled back to the
7180 catch FOO: If there is a FOO exception handler in the dynamic scope,
7181 set a breakpoint to catch exceptions which may be raised there.
7182 Multiple exceptions (``catch foo bar baz'') may be caught.
7184 info catch: Lists all exceptions which may be caught in the
7185 current stack frame.
7188 * Minor command changes
7190 The command ``call func (arg, arg, ...)'' now acts like the print
7191 command, except it does not print or save a value if the function's result
7192 is void. This is similar to dbx usage.
7194 The ``up'' and ``down'' commands now always print the frame they end up
7195 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7196 frames without printing.
7198 * New directory command
7200 'dir' now adds directories to the FRONT of the source search path.
7201 The path starts off empty. Source files that contain debug information
7202 about the directory in which they were compiled can be found even
7203 with an empty path; Sun CC and GCC include this information. If GDB can't
7204 find your source file in the current directory, type "dir .".
7206 * Configuring GDB for compilation
7208 For normal use, type ``./configure host''. See README or gdb.texinfo
7211 GDB now handles cross debugging. If you are remotely debugging between
7212 two different machines, type ``./configure host -target=targ''.
7213 Host is the machine where GDB will run; targ is the machine
7214 where the program that you are debugging will run.