1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support access to additional registers on
7 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
10 * GDB now has experimental support for the compilation and injection of
11 C++ source code into the inferior. This beta release does not include
12 support for several language features, such as templates, constructors,
15 This feature requires GCC 7.1 or higher built with libcp1.so
18 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
19 can be passed using the '[ADDRESS]:PORT' notation, or the regular
20 'ADDRESS:PORT' method.
22 * DWARF index cache: GDB can now automatically save indices of DWARF
23 symbols on disk to speed up further loading of the same binaries.
25 * Ada task switching is now supported on aarch64-elf targets when
26 debugging a program using the Ravenscar Profile. For more information,
27 see the "Tasking Support when using the Ravenscar Profile" section
28 in the GDB user manual.
30 * GDB in batch mode now exits with status 1 if the last command to be
33 * Changes to the "frame", "select-frame", and "info frame" CLI
34 commands. These commands all now take a frame specification which
35 is either a frame level, or one of the keywords 'level', 'address',
36 'function', or 'view' followed by a parameter. Selecting a frame by
37 address, or viewing a frame outside the current backtrace now
38 requires the use of a keyword. Selecting a frame by level is
39 unchanged. The MI comment "-stack-select-frame" is unchanged.
47 set debug compile-cplus-types
48 show debug compile-cplus-types
49 Control the display of debug output about type conversion in the
50 C++ compile feature. Commands have no effect while compiliong
55 Control whether debug output about files/functions skipping is
58 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
59 Apply a command to some frames.
60 FLAG arguments allow to control what output to produce and how to handle
61 errors raised when applying COMMAND to a frame.
64 Apply a command to all threads (ignoring errors and empty output).
65 Shortcut for 'thread apply all -s COMMAND'.
68 Apply a command to all frames (ignoring errors and empty output).
69 Shortcut for 'frame apply all -s COMMAND'.
72 Apply a command to all frames of all threads (ignoring errors and empty
74 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
76 maint set dwarf unwinders (on|off)
77 maint show dwarf unwinders
78 Control whether DWARF unwinders can be used.
81 Display a list of open files for a process.
85 target remote FILENAME
86 target extended-remote FILENAME
87 If FILENAME is a Unix domain socket, GDB will attempt to connect
88 to this socket instead of opening FILENAME as a character device.
90 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
91 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
92 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
93 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
94 These commands can now print only the searched entities
95 matching the provided regexp(s), giving a condition
96 on the entity names or entity types. The flag -q disables
97 printing headers or informations messages.
103 These commands now determine the syntax for the shown entities
104 according to the language chosen by `set language'. In particular,
105 `set language auto' means to automatically choose the language of
108 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
109 The 'thread apply' command accepts new FLAG arguments.
110 FLAG arguments allow to control what output to produce and how to handle
111 errors raised when applying COMMAND to a thread.
113 set tui tab-width NCHARS
114 show tui tab-width NCHARS
115 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
119 ** The '-data-disassemble' MI command now accepts an '-a' option to
120 disassemble the whole function surrounding the given program
121 counter value or function name. Support for this feature can be
122 verified by using the "-list-features" command, which should
123 contain "data-disassemble-a-option".
125 ** Command responses and notifications that include a frame now include
126 the frame's architecture in a new "arch" attribute.
128 * New native configurations
130 GNU/Linux/RISC-V riscv*-*-linux*
131 FreeBSD/riscv riscv*-*-freebsd*
135 GNU/Linux/RISC-V riscv*-*-linux*
137 CSKY GNU/LINUX csky*-*-linux
138 FreeBSD/riscv riscv*-*-freebsd*
142 ** The gdb.Inferior type has a new 'progspace' property, which is the program
143 space associated to that inferior.
145 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
146 of objfiles associated to that program space.
148 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
149 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
152 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
153 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
154 correct and did not work properly.
160 Enable or disable the undefined behavior sanitizer. This is
161 disabled by default, but passing --enable-ubsan=yes or
162 --enable-ubsan=auto to configure will enable it. Enabling this can
163 cause a performance penalty. The undefined behavior sanitizer was
164 first introduced in GCC 4.9.
166 *** Changes in GDB 8.2
168 * The 'set disassembler-options' command now supports specifying options
171 * The 'symbol-file' command now accepts an '-o' option to add a relative
172 offset to all sections.
174 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
175 a relative offset to all sections, but it allows to override the load
176 address of individual sections using '-s'.
178 * The 'add-symbol-file' command no longer requires the second argument
179 (address of the text section).
181 * The endianness used with the 'set endian auto' mode in the absence of
182 an executable selected for debugging is now the last endianness chosen
183 either by one of the 'set endian big' and 'set endian little' commands
184 or by inferring from the last executable used, rather than the startup
187 * The pager now allows a "c" response, meaning to disable the pager
188 for the rest of the current command.
190 * The commands 'info variables/functions/types' now show the source line
191 numbers of symbol definitions when available.
193 * 'info proc' now works on running processes on FreeBSD systems and core
194 files created on FreeBSD systems.
196 * C expressions can now use _Alignof, and C++ expressions can now use
199 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
200 the vector length while the process is running.
206 Control display of debugging info regarding the FreeBSD native target.
208 set|show varsize-limit
209 This new setting allows the user to control the maximum size of Ada
210 objects being printed when those objects have a variable type,
211 instead of that maximum size being hardcoded to 65536 bytes.
213 set|show record btrace cpu
214 Controls the processor to be used for enabling errata workarounds for
217 maint check libthread-db
218 Run integrity checks on the current inferior's thread debugging
221 maint set check-libthread-db (on|off)
222 maint show check-libthread-db
223 Control whether to run integrity checks on inferior specific thread
224 debugging libraries as they are loaded. The default is not to
229 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
231 ** The commands attached to a breakpoint can be set by assigning to
232 the breakpoint's "commands" field.
234 ** gdb.execute can now execute multi-line gdb commands.
236 ** The new functions gdb.convenience_variable and
237 gdb.set_convenience_variable can be used to get and set the value
238 of convenience variables.
240 ** A gdb.Parameter will no longer print the "set" help text on an
241 ordinary "set"; instead by default a "set" will be silent unless
242 the get_set_string method returns a non-empty string.
246 RiscV ELF riscv*-*-elf
248 * Removed targets and native configurations
250 m88k running OpenBSD m88*-*-openbsd*
251 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
252 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
253 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
255 * Aarch64/Linux hardware watchpoints improvements
257 Hardware watchpoints on unaligned addresses are now properly
258 supported when running Linux kernel 4.10 or higher: read and access
259 watchpoints are no longer spuriously missed, and all watchpoints
260 lengths between 1 and 8 bytes are supported. On older kernels,
261 watchpoints set on unaligned addresses are no longer missed, with
262 the tradeoff that there is a possibility of false hits being
267 --enable-codesign=CERT
268 This can be used to invoke "codesign -s CERT" after building gdb.
269 This option is useful on macOS, where code signing is required for
270 gdb to work properly.
272 --disable-gdbcli has been removed
273 This is now silently accepted, but does nothing.
275 *** Changes in GDB 8.1
277 * GDB now supports dynamically creating arbitrary register groups specified
278 in XML target descriptions. This allows for finer grain grouping of
279 registers on systems with a large amount of registers.
281 * The 'ptype' command now accepts a '/o' flag, which prints the
282 offsets and sizes of fields in a struct, like the pahole(1) tool.
284 * New "--readnever" command line option instructs GDB to not read each
285 symbol file's symbolic debug information. This makes startup faster
286 but at the expense of not being able to perform symbolic debugging.
287 This option is intended for use cases where symbolic debugging will
288 not be used, e.g., when you only need to dump the debuggee's core.
290 * GDB now uses the GNU MPFR library, if available, to emulate target
291 floating-point arithmetic during expression evaluation when the target
292 uses different floating-point formats than the host. At least version
293 3.1 of GNU MPFR is required.
295 * GDB now supports access to the guarded-storage-control registers and the
296 software-based guarded-storage broadcast control registers on IBM z14.
298 * On Unix systems, GDB now supports transmitting environment variables
299 that are to be set or unset to GDBserver. These variables will
300 affect the environment to be passed to the remote inferior.
302 To inform GDB of environment variables that are to be transmitted to
303 GDBserver, use the "set environment" command. Only user set
304 environment variables are sent to GDBserver.
306 To inform GDB of environment variables that are to be unset before
307 the remote inferior is started by the GDBserver, use the "unset
308 environment" command.
310 * Completion improvements
312 ** GDB can now complete function parameters in linespecs and
313 explicit locations without quoting. When setting breakpoints,
314 quoting around functions names to help with TAB-completion is
315 generally no longer necessary. For example, this now completes
318 (gdb) b function(in[TAB]
319 (gdb) b function(int)
321 Related, GDB is no longer confused with completing functions in
322 C++ anonymous namespaces:
325 (gdb) b (anonymous namespace)::[TAB][TAB]
326 (anonymous namespace)::a_function()
327 (anonymous namespace)::b_function()
329 ** GDB now has much improved linespec and explicit locations TAB
330 completion support, that better understands what you're
331 completing and offers better suggestions. For example, GDB no
332 longer offers data symbols as possible completions when you're
333 setting a breakpoint.
335 ** GDB now TAB-completes label symbol names.
337 ** The "complete" command now mimics TAB completion accurately.
339 * New command line options (gcore)
342 Dump all memory mappings.
344 * Breakpoints on C++ functions are now set on all scopes by default
346 By default, breakpoints on functions/methods are now interpreted as
347 specifying all functions with the given name ignoring missing
348 leading scopes (namespaces and classes).
350 For example, assuming a C++ program with symbols named:
355 both commands "break func()" and "break B::func()" set a breakpoint
358 You can use the new flag "-qualified" to override this. This makes
359 GDB interpret the specified function name as a complete
360 fully-qualified name instead. For example, using the same C++
361 program, the "break -q B::func" command sets a breakpoint on
362 "B::func", only. A parameter has been added to the Python
363 gdb.Breakpoint constructor to achieve the same result when creating
364 a breakpoint from Python.
366 * Breakpoints on functions marked with C++ ABI tags
368 GDB can now set breakpoints on functions marked with C++ ABI tags
369 (e.g., [abi:cxx11]). See here for a description of ABI tags:
370 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
372 Functions with a C++11 abi tag are demangled/displayed like this:
374 function[abi:cxx11](int)
377 You can now set a breakpoint on such functions simply as if they had
380 (gdb) b function(int)
382 Or if you need to disambiguate between tags, like:
384 (gdb) b function[abi:other_tag](int)
386 Tab completion was adjusted accordingly as well.
390 ** New events gdb.new_inferior, gdb.inferior_deleted, and
391 gdb.new_thread are emitted. See the manual for further
392 description of these.
394 ** A new function, "gdb.rbreak" has been added to the Python API.
395 This function allows the setting of a large number of breakpoints
396 via a regex pattern in Python. See the manual for further details.
398 ** Python breakpoints can now accept explicit locations. See the
399 manual for a further description of this feature.
402 * New features in the GDB remote stub, GDBserver
404 ** GDBserver is now able to start inferior processes with a
405 specified initial working directory.
407 The user can set the desired working directory to be used from
408 GDB using the new "set cwd" command.
410 ** New "--selftest" command line option runs some GDBserver self
411 tests. These self tests are disabled in releases.
413 ** On Unix systems, GDBserver now does globbing expansion and variable
414 substitution in inferior command line arguments.
416 This is done by starting inferiors using a shell, like GDB does.
417 See "set startup-with-shell" in the user manual for how to disable
418 this from GDB when using "target extended-remote". When using
419 "target remote", you can disable the startup with shell by using the
420 new "--no-startup-with-shell" GDBserver command line option.
422 ** On Unix systems, GDBserver now supports receiving environment
423 variables that are to be set or unset from GDB. These variables
424 will affect the environment to be passed to the inferior.
426 * When catching an Ada exception raised with a message, GDB now prints
427 the message in the catchpoint hit notification. In GDB/MI mode, that
428 information is provided as an extra field named "exception-message"
429 in the *stopped notification.
431 * Trait objects can now be inspected When debugging Rust code. This
432 requires compiler support which will appear in Rust 1.24.
436 QEnvironmentHexEncoded
437 Inform GDBserver of an environment variable that is to be passed to
438 the inferior when starting it.
441 Inform GDBserver of an environment variable that is to be unset
442 before starting the remote inferior.
445 Inform GDBserver that the environment should be reset (i.e.,
446 user-set environment variables should be unset).
449 Indicates whether the inferior must be started with a shell or not.
452 Tell GDBserver that the inferior to be started should use a specific
455 * The "maintenance print c-tdesc" command now takes an optional
456 argument which is the file name of XML target description.
458 * The "maintenance selftest" command now takes an optional argument to
459 filter the tests to be run.
461 * The "enable", and "disable" commands now accept a range of
462 breakpoint locations, e.g. "enable 1.3-5".
467 Set and show the current working directory for the inferior.
470 Set and show compilation command used for compiling and injecting code
471 with the 'compile' commands.
473 set debug separate-debug-file
474 show debug separate-debug-file
475 Control the display of debug output about separate debug file search.
477 set dump-excluded-mappings
478 show dump-excluded-mappings
479 Control whether mappings marked with the VM_DONTDUMP flag should be
480 dumped when generating a core file.
483 List the registered selftests.
486 Start the debugged program stopping at the first instruction.
489 Control display of debugging messages related to OpenRISC targets.
491 set|show print type nested-type-limit
492 Set and show the limit of nesting level for nested types that the
493 type printer will show.
495 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
498 * Safer/improved support for debugging with no debug info
500 GDB no longer assumes functions with no debug information return
503 This means that GDB now refuses to call such functions unless you
504 tell it the function's type, by either casting the call to the
505 declared return type, or by casting the function to a function
506 pointer of the right type, and calling that:
508 (gdb) p getenv ("PATH")
509 'getenv' has unknown return type; cast the call to its declared return type
510 (gdb) p (char *) getenv ("PATH")
511 $1 = 0x7fffffffe "/usr/local/bin:/"...
512 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
513 $2 = 0x7fffffffe "/usr/local/bin:/"...
515 Similarly, GDB no longer assumes that global variables with no debug
516 info have type 'int', and refuses to print the variable's value
517 unless you tell it the variable's type:
520 'var' has unknown type; cast it to its declared type
524 * New native configurations
526 FreeBSD/aarch64 aarch64*-*-freebsd*
527 FreeBSD/arm arm*-*-freebsd*
531 FreeBSD/aarch64 aarch64*-*-freebsd*
532 FreeBSD/arm arm*-*-freebsd*
533 OpenRISC ELF or1k*-*-elf
535 * Removed targets and native configurations
537 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
539 *** Changes in GDB 8.0
541 * GDB now supports access to the PKU register on GNU/Linux. The register is
542 added by the Memory Protection Keys for Userspace feature which will be
543 available in future Intel CPUs.
545 * GDB now supports C++11 rvalue references.
549 ** New functions to start, stop and access a running btrace recording.
550 ** Rvalue references are now supported in gdb.Type.
552 * GDB now supports recording and replaying rdrand and rdseed Intel 64
555 * Building GDB and GDBserver now requires a C++11 compiler.
557 For example, GCC 4.8 or later.
559 It is no longer possible to build GDB or GDBserver with a C
560 compiler. The --disable-build-with-cxx configure option has been
563 * Building GDB and GDBserver now requires GNU make >= 3.81.
565 It is no longer supported to build GDB or GDBserver with another
566 implementation of the make program or an earlier version of GNU make.
568 * Native debugging on MS-Windows supports command-line redirection
570 Command-line arguments used for starting programs on MS-Windows can
571 now include redirection symbols supported by native Windows shells,
572 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
573 as "run", "start", and "set args", as well as the corresponding MI
576 * Support for thread names on MS-Windows.
578 GDB now catches and handles the special exception that programs
579 running on MS-Windows use to assign names to threads in the
582 * Support for Java programs compiled with gcj has been removed.
584 * User commands now accept an unlimited number of arguments.
585 Previously, only up to 10 was accepted.
587 * The "eval" command now expands user-defined command arguments.
589 This makes it easier to process a variable number of arguments:
594 eval "print $arg%d", $i
599 * Target descriptions can now describe registers for sparc32 and sparc64.
601 * GDB now supports DWARF version 5 (debug information format).
602 Its .debug_names index is not yet supported.
604 * New native configurations
606 FreeBSD/mips mips*-*-freebsd
610 Synopsys ARC arc*-*-elf32
611 FreeBSD/mips mips*-*-freebsd
613 * Removed targets and native configurations
615 Alpha running FreeBSD alpha*-*-freebsd*
616 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
621 Erases all the flash memory regions reported by the target.
623 maint print arc arc-instruction address
624 Print internal disassembler information about instruction at a given address.
628 set disassembler-options
629 show disassembler-options
630 Controls the passing of target specific information to the disassembler.
631 If it is necessary to specify more than one disassembler option then
632 multiple options can be placed together into a comma separated list.
633 The default value is the empty string. Currently, the only supported
634 targets are ARM, PowerPC and S/390.
639 Erases all the flash memory regions reported by the target. This is
640 equivalent to the CLI command flash-erase.
642 -file-list-shared-libraries
643 List the shared libraries in the program. This is
644 equivalent to the CLI command "info shared".
647 Catchpoints stopping the program when Ada exceptions are
648 handled. This is equivalent to the CLI command "catch handlers".
650 *** Changes in GDB 7.12
652 * GDB and GDBserver now build with a C++ compiler by default.
654 The --enable-build-with-cxx configure option is now enabled by
655 default. One must now explicitly configure with
656 --disable-build-with-cxx in order to build with a C compiler. This
657 option will be removed in a future release.
659 * GDBserver now supports recording btrace without maintaining an active
662 * GDB now supports a negative repeat count in the 'x' command to examine
663 memory backward from the given address. For example:
666 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
667 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
668 (gdb) x/-5i 0x0000000000400580
669 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
670 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
671 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
672 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
673 0x40057b <main(int, char**)+25>:
674 callq 0x400536 <Func1(int, char const*)>
676 * Fortran: Support structures with fields of dynamic types and
677 arrays of dynamic types.
679 * The symbol dumping maintenance commands have new syntax.
680 maint print symbols [-pc address] [--] [filename]
681 maint print symbols [-objfile objfile] [-source source] [--] [filename]
682 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
683 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
684 maint print msymbols [-objfile objfile] [--] [filename]
686 * GDB now supports multibit bitfields and enums in target register
689 * New Python-based convenience function $_as_string(val), which returns
690 the textual representation of a value. This function is especially
691 useful to obtain the text label of an enum value.
693 * Intel MPX bound violation handling.
695 Segmentation faults caused by a Intel MPX boundary violation
696 now display the kind of violation (upper or lower), the memory
697 address accessed and the memory bounds, along with the usual
698 signal received and code location.
702 Program received signal SIGSEGV, Segmentation fault
703 Upper bound violation while accessing address 0x7fffffffc3b3
704 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
705 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
707 * Rust language support.
708 GDB now supports debugging programs written in the Rust programming
709 language. See https://www.rust-lang.org/ for more information about
712 * Support for running interpreters on specified input/output devices
714 GDB now supports a new mechanism that allows frontends to provide
715 fully featured GDB console views, as a better alternative to
716 building such views on top of the "-interpreter-exec console"
717 command. See the new "new-ui" command below. With that command,
718 frontends can now start GDB in the traditional command-line mode
719 running in an embedded terminal emulator widget, and create a
720 separate MI interpreter running on a specified i/o device. In this
721 way, GDB handles line editing, history, tab completion, etc. in the
722 console all by itself, and the GUI uses the separate MI interpreter
723 for its own control and synchronization, invisible to the command
726 * The "catch syscall" command catches groups of related syscalls.
728 The "catch syscall" command now supports catching a group of related
729 syscalls using the 'group:' or 'g:' prefix.
734 skip -gfile file-glob-pattern
735 skip -function function
736 skip -rfunction regular-expression
737 A generalized form of the skip command, with new support for
738 glob-style file names and regular expressions for function names.
739 Additionally, a file spec and a function spec may now be combined.
741 maint info line-table REGEXP
742 Display the contents of GDB's internal line table data struture.
745 Run any GDB unit tests that were compiled in.
748 Start a new user interface instance running INTERP as interpreter,
749 using the TTY file for input/output.
753 ** gdb.Breakpoint objects have a new attribute "pending", which
754 indicates whether the breakpoint is pending.
755 ** Three new breakpoint-related events have been added:
756 gdb.breakpoint_created, gdb.breakpoint_modified, and
757 gdb.breakpoint_deleted.
760 Signal ("set") the given MS-Windows event object. This is used in
761 conjunction with the Windows JIT debugging (AeDebug) support, where
762 the OS suspends a crashing process until a debugger can attach to
763 it. Resuming the crashing process, in order to debug it, is done by
766 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
767 was added in GDBserver, including JIT compiling fast tracepoint's
768 conditional expression bytecode into native code.
770 * Support for various remote target protocols and ROM monitors has
773 target m32rsdi Remote M32R debugging over SDI
774 target mips MIPS remote debugging protocol
775 target pmon PMON ROM monitor
776 target ddb NEC's DDB variant of PMON for Vr4300
777 target rockhopper NEC RockHopper variant of PMON
778 target lsi LSI variant of PMO
780 * Support for tracepoints and fast tracepoints on powerpc-linux,
781 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
782 including JIT compiling fast tracepoint's conditional expression
783 bytecode into native code.
785 * MI async record =record-started now includes the method and format used for
786 recording. For example:
788 =record-started,thread-group="i1",method="btrace",format="bts"
790 * MI async record =thread-selected now includes the frame field. For example:
792 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
796 Andes NDS32 nds32*-*-elf
798 *** Changes in GDB 7.11
800 * GDB now supports debugging kernel-based threads on FreeBSD.
802 * Per-inferior thread numbers
804 Thread numbers are now per inferior instead of global. If you're
805 debugging multiple inferiors, GDB displays thread IDs using a
806 qualified INF_NUM.THR_NUM form. For example:
810 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
811 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
812 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
813 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
815 As consequence, thread numbers as visible in the $_thread
816 convenience variable and in Python's InferiorThread.num attribute
817 are no longer unique between inferiors.
819 GDB now maintains a second thread ID per thread, referred to as the
820 global thread ID, which is the new equivalent of thread numbers in
821 previous releases. See also $_gthread below.
823 For backwards compatibility, MI's thread IDs always refer to global
826 * Commands that accept thread IDs now accept the qualified
827 INF_NUM.THR_NUM form as well. For example:
830 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
833 * In commands that accept a list of thread IDs, you can now refer to
834 all threads of an inferior using a star wildcard. GDB accepts
835 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
836 refer to all threads of the current inferior. For example, "info
839 * You can use "info threads -gid" to display the global thread ID of
842 * The new convenience variable $_gthread holds the global number of
845 * The new convenience variable $_inferior holds the number of the
848 * GDB now displays the ID and name of the thread that hit a breakpoint
849 or received a signal, if your program is multi-threaded. For
852 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
853 Thread 1 "main" received signal SIGINT, Interrupt.
855 * Record btrace now supports non-stop mode.
857 * Support for tracepoints on aarch64-linux was added in GDBserver.
859 * The 'record instruction-history' command now indicates speculative execution
860 when using the Intel Processor Trace recording format.
862 * GDB now allows users to specify explicit locations, bypassing
863 the linespec parser. This feature is also available to GDB/MI
866 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
867 GDB now is able to debug both AArch64 applications and ARM applications
870 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
871 including JIT compiling fast tracepoint's conditional expression bytecode
874 * GDB now supports displaced stepping on AArch64 GNU/Linux.
876 * "info threads", "info inferiors", "info display", "info checkpoints"
877 and "maint info program-spaces" now list the corresponding items in
878 ascending ID order, for consistency with all other "info" commands.
880 * In Ada, the overloads selection menu has been enhanced to display the
881 parameter types and the return types for the matching overloaded subprograms.
885 maint set target-non-stop (on|off|auto)
886 maint show target-non-stop
887 Control whether GDB targets always operate in non-stop mode even if
888 "set non-stop" is "off". The default is "auto", meaning non-stop
889 mode is enabled if supported by the target.
891 maint set bfd-sharing
892 maint show bfd-sharing
893 Control the reuse of bfd objects.
897 Control display of debugging info regarding bfd caching.
901 Control display of debugging info regarding FreeBSD threads.
903 set remote multiprocess-extensions-packet
904 show remote multiprocess-extensions-packet
905 Set/show the use of the remote protocol multiprocess extensions.
907 set remote thread-events
908 show remote thread-events
909 Set/show the use of thread create/exit events.
911 set ada print-signatures on|off
912 show ada print-signatures"
913 Control whether parameter types and return types are displayed in overloads
914 selection menus. It is activaled (@code{on}) by default.
918 Controls the maximum size of memory, in bytes, that GDB will
919 allocate for value contents. Prevents incorrect programs from
920 causing GDB to allocate overly large buffers. Default is 64k.
922 * The "disassemble" command accepts a new modifier: /s.
923 It prints mixed source+disassembly like /m with two differences:
924 - disassembled instructions are now printed in program order, and
925 - and source for all relevant files is now printed.
926 The "/m" option is now considered deprecated: its "source-centric"
927 output hasn't proved useful in practice.
929 * The "record instruction-history" command accepts a new modifier: /s.
930 It behaves exactly like /m and prints mixed source+disassembly.
932 * The "set scheduler-locking" command supports a new mode "replay".
933 It behaves like "off" in record mode and like "on" in replay mode.
935 * Support for various ROM monitors has been removed:
937 target dbug dBUG ROM monitor for Motorola ColdFire
938 target picobug Motorola picobug monitor
939 target dink32 DINK32 ROM monitor for PowerPC
940 target m32r Renesas M32R/D ROM monitor
941 target mon2000 mon2000 ROM monitor
942 target ppcbug PPCBUG ROM monitor for PowerPC
944 * Support for reading/writing memory and extracting values on architectures
945 whose memory is addressable in units of any integral multiple of 8 bits.
948 Allows to break when an Ada exception is handled.
953 Indicates that an exec system call was executed.
955 exec-events feature in qSupported
956 The qSupported packet allows GDB to request support for exec
957 events using the new 'gdbfeature' exec-event, and the qSupported
958 response can contain the corresponding 'stubfeature'. Set and
959 show commands can be used to display whether these features are enabled.
962 Equivalent to interrupting with the ^C character, but works in
965 thread created stop reason (T05 create:...)
966 Indicates that the thread was just created and is stopped at entry.
968 thread exit stop reply (w exitcode;tid)
969 Indicates that the thread has terminated.
972 Enables/disables thread create and exit event reporting. For
973 example, this is used in non-stop mode when GDB stops a set of
974 threads and synchronously waits for the their corresponding stop
975 replies. Without exit events, if one of the threads exits, GDB
976 would hang forever not knowing that it should no longer expect a
977 stop for that same thread.
980 Indicates that there are no resumed threads left in the target (all
981 threads are stopped). The remote stub reports support for this stop
982 reply to GDB's qSupported query.
985 Enables/disables catching syscalls from the inferior process.
986 The remote stub reports support for this packet to GDB's qSupported query.
988 syscall_entry stop reason
989 Indicates that a syscall was just called.
991 syscall_return stop reason
992 Indicates that a syscall just returned.
994 * Extended-remote exec events
996 ** GDB now has support for exec events on extended-remote Linux targets.
997 For such targets with Linux kernels 2.5.46 and later, this enables
998 follow-exec-mode and exec catchpoints.
1000 set remote exec-event-feature-packet
1001 show remote exec-event-feature-packet
1002 Set/show the use of the remote exec event feature.
1004 * Thread names in remote protocol
1006 The reply to qXfer:threads:read may now include a name attribute for each
1009 * Target remote mode fork and exec events
1011 ** GDB now has support for fork and exec events on target remote mode
1012 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1013 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1014 fork and exec catchpoints.
1016 * Remote syscall events
1018 ** GDB now has support for catch syscall on remote Linux targets,
1019 currently enabled on x86/x86_64 architectures.
1021 set remote catch-syscall-packet
1022 show remote catch-syscall-packet
1023 Set/show the use of the remote catch syscall feature.
1027 ** The -var-set-format command now accepts the zero-hexadecimal
1028 format. It outputs data in hexadecimal format with zero-padding on the
1033 ** gdb.InferiorThread objects have a new attribute "global_num",
1034 which refers to the thread's global thread ID. The existing
1035 "num" attribute now refers to the thread's per-inferior number.
1036 See "Per-inferior thread numbers" above.
1037 ** gdb.InferiorThread objects have a new attribute "inferior", which
1038 is the Inferior object the thread belongs to.
1040 *** Changes in GDB 7.10
1042 * Support for process record-replay and reverse debugging on aarch64*-linux*
1043 targets has been added. GDB now supports recording of A64 instruction set
1044 including advance SIMD instructions.
1046 * Support for Sun's version of the "stabs" debug file format has been removed.
1048 * GDB now honors the content of the file /proc/PID/coredump_filter
1049 (PID is the process ID) on GNU/Linux systems. This file can be used
1050 to specify the types of memory mappings that will be included in a
1051 corefile. For more information, please refer to the manual page of
1052 "core(5)". GDB also has a new command: "set use-coredump-filter
1053 on|off". It allows to set whether GDB will read the content of the
1054 /proc/PID/coredump_filter file when generating a corefile.
1056 * The "info os" command on GNU/Linux can now display information on
1058 "info os cpus" Listing of all cpus/cores on the system
1060 * GDB has two new commands: "set serial parity odd|even|none" and
1061 "show serial parity". These allows to set or show parity for the
1064 * The "info source" command now displays the producer string if it was
1065 present in the debug info. This typically includes the compiler version
1066 and may include things like its command line arguments.
1068 * The "info dll", an alias of the "info sharedlibrary" command,
1069 is now available on all platforms.
1071 * Directory names supplied to the "set sysroot" commands may be
1072 prefixed with "target:" to tell GDB to access shared libraries from
1073 the target system, be it local or remote. This replaces the prefix
1074 "remote:". The default sysroot has been changed from "" to
1075 "target:". "remote:" is automatically converted to "target:" for
1076 backward compatibility.
1078 * The system root specified by "set sysroot" will be prepended to the
1079 filename of the main executable (if reported to GDB as absolute by
1080 the operating system) when starting processes remotely, and when
1081 attaching to already-running local or remote processes.
1083 * GDB now supports automatic location and retrieval of executable
1084 files from remote targets. Remote debugging can now be initiated
1085 using only a "target remote" or "target extended-remote" command
1086 (no "set sysroot" or "file" commands are required). See "New remote
1089 * The "dump" command now supports verilog hex format.
1091 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1093 * On GNU/Linux, GDB and gdbserver are now able to access executable
1094 and shared library files without a "set sysroot" command when
1095 attaching to processes running in different mount namespaces from
1096 the debugger. This makes it possible to attach to processes in
1097 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1098 See "New remote packets" below.
1100 * The "tui reg" command now provides completion for all of the
1101 available register groups, including target specific groups.
1103 * The HISTSIZE environment variable is no longer read when determining
1104 the size of GDB's command history. GDB now instead reads the dedicated
1105 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1106 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1111 ** Memory ports can now be unbuffered.
1115 ** gdb.Objfile objects have a new attribute "username",
1116 which is the name of the objfile as specified by the user,
1117 without, for example, resolving symlinks.
1118 ** You can now write frame unwinders in Python.
1119 ** gdb.Type objects have a new method "optimized_out",
1120 returning optimized out gdb.Value instance of this type.
1121 ** gdb.Value objects have new methods "reference_value" and
1122 "const_value" which return a reference to the value and a
1123 "const" version of the value respectively.
1127 maint print symbol-cache
1128 Print the contents of the symbol cache.
1130 maint print symbol-cache-statistics
1131 Print statistics of symbol cache usage.
1133 maint flush-symbol-cache
1134 Flush the contents of the symbol cache.
1138 Start branch trace recording using Branch Trace Store (BTS) format.
1141 Evaluate expression by using the compiler and print result.
1145 Explicit commands for enabling and disabling tui mode.
1148 set mpx bound on i386 and amd64
1149 Support for bound table investigation on Intel MPX enabled applications.
1153 Start branch trace recording using Intel Processor Trace format.
1156 Print information about branch tracing internals.
1158 maint btrace packet-history
1159 Print the raw branch tracing data.
1161 maint btrace clear-packet-history
1162 Discard the stored raw branch tracing data.
1165 Discard all branch tracing data. It will be fetched and processed
1166 anew by the next "record" command.
1171 Renamed from "set debug dwarf2-die".
1172 show debug dwarf-die
1173 Renamed from "show debug dwarf2-die".
1175 set debug dwarf-read
1176 Renamed from "set debug dwarf2-read".
1177 show debug dwarf-read
1178 Renamed from "show debug dwarf2-read".
1180 maint set dwarf always-disassemble
1181 Renamed from "maint set dwarf2 always-disassemble".
1182 maint show dwarf always-disassemble
1183 Renamed from "maint show dwarf2 always-disassemble".
1185 maint set dwarf max-cache-age
1186 Renamed from "maint set dwarf2 max-cache-age".
1187 maint show dwarf max-cache-age
1188 Renamed from "maint show dwarf2 max-cache-age".
1190 set debug dwarf-line
1191 show debug dwarf-line
1192 Control display of debugging info regarding DWARF line processing.
1195 show max-completions
1196 Set the maximum number of candidates to be considered during
1197 completion. The default value is 200. This limit allows GDB
1198 to avoid generating large completion lists, the computation of
1199 which can cause the debugger to become temporarily unresponsive.
1201 set history remove-duplicates
1202 show history remove-duplicates
1203 Control the removal of duplicate history entries.
1205 maint set symbol-cache-size
1206 maint show symbol-cache-size
1207 Control the size of the symbol cache.
1209 set|show record btrace bts buffer-size
1210 Set and show the size of the ring buffer used for branch tracing in
1212 The obtained size may differ from the requested size. Use "info
1213 record" to see the obtained buffer size.
1215 set debug linux-namespaces
1216 show debug linux-namespaces
1217 Control display of debugging info regarding Linux namespaces.
1219 set|show record btrace pt buffer-size
1220 Set and show the size of the ring buffer used for branch tracing in
1221 Intel Processor Trace format.
1222 The obtained size may differ from the requested size. Use "info
1223 record" to see the obtained buffer size.
1225 maint set|show btrace pt skip-pad
1226 Set and show whether PAD packets are skipped when computing the
1229 * The command 'thread apply all' can now support new option '-ascending'
1230 to call its specified command for all threads in ascending order.
1232 * Python/Guile scripting
1234 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1235 special section named `.debug_gdb_scripts'.
1237 * New remote packets
1239 qXfer:btrace-conf:read
1240 Return the branch trace configuration for the current thread.
1242 Qbtrace-conf:bts:size
1243 Set the requested ring buffer size for branch tracing in BTS format.
1246 Enable Intel Procesor Trace-based branch tracing for the current
1247 process. The remote stub reports support for this packet to GDB's
1250 Qbtrace-conf:pt:size
1251 Set the requested ring buffer size for branch tracing in Intel Processor
1255 Indicates a memory breakpoint instruction was executed, irrespective
1256 of whether it was GDB that planted the breakpoint or the breakpoint
1257 is hardcoded in the program. This is required for correct non-stop
1261 Indicates the target stopped for a hardware breakpoint. This is
1262 required for correct non-stop mode operation.
1265 Return information about files on the remote system.
1267 qXfer:exec-file:read
1268 Return the full absolute name of the file that was executed to
1269 create a process running on the remote system.
1272 Select the filesystem on which vFile: operations with filename
1273 arguments will operate. This is required for GDB to be able to
1274 access files on remote targets where the remote stub does not
1275 share a common filesystem with the inferior(s).
1278 Indicates that a fork system call was executed.
1281 Indicates that a vfork system call was executed.
1283 vforkdone stop reason
1284 Indicates that a vfork child of the specified process has executed
1285 an exec or exit, allowing the vfork parent to resume execution.
1287 fork-events and vfork-events features in qSupported
1288 The qSupported packet allows GDB to request support for fork and
1289 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1290 and the qSupported response can contain the corresponding
1291 'stubfeatures'. Set and show commands can be used to display
1292 whether these features are enabled.
1294 * Extended-remote fork events
1296 ** GDB now has support for fork events on extended-remote Linux
1297 targets. For targets with Linux kernels 2.5.60 and later, this
1298 enables follow-fork-mode and detach-on-fork for both fork and
1299 vfork, as well as fork and vfork catchpoints.
1301 * The info record command now shows the recording format and the
1302 branch tracing configuration for the current thread when using
1303 the btrace record target.
1304 For the BTS format, it shows the ring buffer size.
1306 * GDB now has support for DTrace USDT (Userland Static Defined
1307 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1309 * GDB now supports access to vector registers on S/390 GNU/Linux
1312 * Removed command line options
1314 -xdb HP-UX XDB compatibility mode.
1316 * Removed targets and native configurations
1318 HP/PA running HP-UX hppa*-*-hpux*
1319 Itanium running HP-UX ia64-*-hpux*
1321 * New configure options
1324 This configure option allows the user to build GDB with support for
1325 Intel Processor Trace (default: auto). This requires libipt.
1327 --with-libipt-prefix=PATH
1328 Specify the path to the version of libipt that GDB should use.
1329 $PATH/include should contain the intel-pt.h header and
1330 $PATH/lib should contain the libipt.so library.
1332 *** Changes in GDB 7.9.1
1336 ** Xmethods can now specify a result type.
1338 *** Changes in GDB 7.9
1340 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1344 ** You can now access frame registers from Python scripts.
1345 ** New attribute 'producer' for gdb.Symtab objects.
1346 ** gdb.Objfile objects have a new attribute "progspace",
1347 which is the gdb.Progspace object of the containing program space.
1348 ** gdb.Objfile objects have a new attribute "owner".
1349 ** gdb.Objfile objects have a new attribute "build_id",
1350 which is the build ID generated when the file was built.
1351 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1352 ** A new event "gdb.clear_objfiles" has been added, triggered when
1353 selecting a new file to debug.
1354 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1355 ** New function gdb.lookup_objfile.
1357 New events which are triggered when GDB modifies the state of the
1360 ** gdb.events.inferior_call_pre: Function call is about to be made.
1361 ** gdb.events.inferior_call_post: Function call has just been made.
1362 ** gdb.events.memory_changed: A memory location has been altered.
1363 ** gdb.events.register_changed: A register has been altered.
1365 * New Python-based convenience functions:
1367 ** $_caller_is(name [, number_of_frames])
1368 ** $_caller_matches(regexp [, number_of_frames])
1369 ** $_any_caller_is(name [, number_of_frames])
1370 ** $_any_caller_matches(regexp [, number_of_frames])
1372 * GDB now supports the compilation and injection of source code into
1373 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1374 to compile the source code to object code, and if successful, inject
1375 and execute that code within the current context of the inferior.
1376 Currently the C language is supported. The commands used to
1377 interface with this new feature are:
1379 compile code [-raw|-r] [--] [source code]
1380 compile file [-raw|-r] filename
1384 demangle [-l language] [--] name
1385 Demangle "name" in the specified language, or the current language
1386 if elided. This command is renamed from the "maint demangle" command.
1387 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1388 as "maint demangler-warning".
1390 queue-signal signal-name-or-number
1391 Queue a signal to be delivered to the thread when it is resumed.
1393 add-auto-load-scripts-directory directory
1394 Add entries to the list of directories from which to load auto-loaded
1397 maint print user-registers
1398 List all currently available "user" registers.
1400 compile code [-r|-raw] [--] [source code]
1401 Compile, inject, and execute in the inferior the executable object
1402 code produced by compiling the provided source code.
1404 compile file [-r|-raw] filename
1405 Compile and inject into the inferior the executable object code
1406 produced by compiling the source code stored in the filename
1409 * On resume, GDB now always passes the signal the program had stopped
1410 for to the thread the signal was sent to, even if the user changed
1411 threads before resuming. Previously GDB would often (but not
1412 always) deliver the signal to the thread that happens to be current
1415 * Conversely, the "signal" command now consistently delivers the
1416 requested signal to the current thread. GDB now asks for
1417 confirmation if the program had stopped for a signal and the user
1418 switched threads meanwhile.
1420 * "breakpoint always-inserted" modes "off" and "auto" merged.
1422 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1423 won't remove breakpoints from the target until all threads stop,
1424 even in non-stop mode. The "auto" mode has been removed, and "off"
1425 is now the default mode.
1429 set debug symbol-lookup
1430 show debug symbol-lookup
1431 Control display of debugging info regarding symbol lookup.
1435 ** The -list-thread-groups command outputs an exit-code field for
1436 inferiors that have exited.
1440 MIPS SDE mips*-sde*-elf*
1444 Support for these obsolete configurations has been removed.
1446 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1447 SGI Irix-5.x mips-*-irix5*
1448 SGI Irix-6.x mips-*-irix6*
1449 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1450 VAX running Ultrix vax-*-ultrix*
1452 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1453 and "assf"), have been removed. Use the "sharedlibrary" command, or
1454 its alias "share", instead.
1456 *** Changes in GDB 7.8
1458 * New command line options
1461 This is an alias for the --data-directory option.
1463 * GDB supports printing and modifying of variable length automatic arrays
1464 as specified in ISO C99.
1466 * The ARM simulator now supports instruction level tracing
1467 with or without disassembly.
1471 GDB now has support for scripting using Guile. Whether this is
1472 available is determined at configure time.
1473 Guile version 2.0 or greater is required.
1474 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1476 * New commands (for set/show, see "New options" below)
1480 Invoke CODE by passing it to the Guile interpreter.
1484 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1486 info auto-load guile-scripts [regexp]
1487 Print the list of automatically loaded Guile scripts.
1489 * The source command is now capable of sourcing Guile scripts.
1490 This feature is dependent on the debugger being built with Guile support.
1494 set print symbol-loading (off|brief|full)
1495 show print symbol-loading
1496 Control whether to print informational messages when loading symbol
1497 information for a file. The default is "full", but when debugging
1498 programs with large numbers of shared libraries the amount of output
1499 becomes less useful.
1501 set guile print-stack (none|message|full)
1502 show guile print-stack
1503 Show a stack trace when an error is encountered in a Guile script.
1505 set auto-load guile-scripts (on|off)
1506 show auto-load guile-scripts
1507 Control auto-loading of Guile script files.
1509 maint ada set ignore-descriptive-types (on|off)
1510 maint ada show ignore-descriptive-types
1511 Control whether the debugger should ignore descriptive types in Ada
1512 programs. The default is not to ignore the descriptive types. See
1513 the user manual for more details on descriptive types and the intended
1514 usage of this option.
1516 set auto-connect-native-target
1518 Control whether GDB is allowed to automatically connect to the
1519 native target for the run, attach, etc. commands when not connected
1520 to any target yet. See also "target native" below.
1522 set record btrace replay-memory-access (read-only|read-write)
1523 show record btrace replay-memory-access
1524 Control what memory accesses are allowed during replay.
1526 maint set target-async (on|off)
1527 maint show target-async
1528 This controls whether GDB targets operate in synchronous or
1529 asynchronous mode. Normally the default is asynchronous, if it is
1530 available; but this can be changed to more easily debug problems
1531 occurring only in synchronous mode.
1533 set mi-async (on|off)
1535 Control whether MI asynchronous mode is preferred. This supersedes
1536 "set target-async" of previous GDB versions.
1538 * "set target-async" is deprecated as a CLI option and is now an alias
1539 for "set mi-async" (only puts MI into async mode).
1541 * Background execution commands (e.g., "c&", "s&", etc.) are now
1542 possible ``out of the box'' if the target supports them. Previously
1543 the user would need to explicitly enable the possibility with the
1544 "set target-async on" command.
1546 * New features in the GDB remote stub, GDBserver
1548 ** New option --debug-format=option1[,option2,...] allows one to add
1549 additional text to each output. At present only timestamps
1550 are supported: --debug-format=timestamps.
1551 Timestamps can also be turned on with the
1552 "monitor set debug-format timestamps" command from GDB.
1554 * The 'record instruction-history' command now starts counting instructions
1555 at one. This also affects the instruction ranges reported by the
1556 'record function-call-history' command when given the /i modifier.
1558 * The command 'record function-call-history' supports a new modifier '/c' to
1559 indent the function names based on their call stack depth.
1560 The fields for the '/i' and '/l' modifier have been reordered.
1561 The source line range is now prefixed with 'at'.
1562 The instruction range is now prefixed with 'inst'.
1563 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1564 "record instruction-history" and "list" commands.
1566 * The ranges given as arguments to the 'record function-call-history' and
1567 'record instruction-history' commands are now inclusive.
1569 * The btrace record target now supports the 'record goto' command.
1570 For locations inside the execution trace, the back trace is computed
1571 based on the information stored in the execution trace.
1573 * The btrace record target supports limited reverse execution and replay.
1574 The target does not record data and therefore does not allow reading
1575 memory or registers.
1577 * The "catch syscall" command now works on s390*-linux* targets.
1579 * The "compare-sections" command is no longer specific to target
1580 remote. It now works with all targets.
1582 * All native targets are now consistently called "native".
1583 Consequently, the "target child", "target GNU", "target djgpp",
1584 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1585 commands have been replaced with "target native". The QNX/NTO port
1586 leaves the "procfs" target in place and adds a "native" target for
1587 consistency with other ports. The impact on users should be minimal
1588 as these commands previously either throwed an error, or were
1589 no-ops. The target's name is visible in the output of the following
1590 commands: "help target", "info target", "info files", "maint print
1593 * The "target native" command now connects to the native target. This
1594 can be used to launch native programs even when "set
1595 auto-connect-native-target" is set to off.
1597 * GDB now supports access to Intel MPX registers on GNU/Linux.
1599 * Support for Intel AVX-512 registers on GNU/Linux.
1600 Support displaying and modifying Intel AVX-512 registers
1601 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1603 * New remote packets
1605 qXfer:btrace:read's annex
1606 The qXfer:btrace:read packet supports a new annex 'delta' to read
1607 branch trace incrementally.
1611 ** Valid Python operations on gdb.Value objects representing
1612 structs/classes invoke the corresponding overloaded operators if
1614 ** New `Xmethods' feature in the Python API. Xmethods are
1615 additional methods or replacements for existing methods of a C++
1616 class. This feature is useful for those cases where a method
1617 defined in C++ source code could be inlined or optimized out by
1618 the compiler, making it unavailable to GDB.
1621 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1623 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1624 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1625 its alias "share", instead.
1627 * The commands "set remotebaud" and "show remotebaud" are no longer
1628 supported. Use "set serial baud" and "show serial baud" (respectively)
1633 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1634 target-async". The latter is left as a deprecated alias of the
1635 former for backward compatibility. If the target supports it,
1636 CLI background execution commands are now always possible by
1637 default, independently of whether the frontend stated a
1638 preference for asynchronous execution with "-gdb-set mi-async".
1639 Previously "-gdb-set target-async off" affected both MI execution
1640 commands and CLI execution commands.
1642 *** Changes in GDB 7.7
1644 * Improved support for process record-replay and reverse debugging on
1645 arm*-linux* targets. Support for thumb32 and syscall instruction
1646 recording has been added.
1648 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1650 * GDB now supports Fission DWP file format version 2.
1651 http://gcc.gnu.org/wiki/DebugFission
1653 * New convenience function "$_isvoid", to check whether an expression
1654 is void. A void expression is an expression where the type of the
1655 result is "void". For example, some convenience variables may be
1656 "void" when evaluated (e.g., "$_exitcode" before the execution of
1657 the program being debugged; or an undefined convenience variable).
1658 Another example, when calling a function whose return type is
1661 * The "maintenance print objfiles" command now takes an optional regexp.
1663 * The "catch syscall" command now works on arm*-linux* targets.
1665 * GDB now consistently shows "<not saved>" when printing values of
1666 registers the debug info indicates have not been saved in the frame
1667 and there's nowhere to retrieve them from
1668 (callee-saved/call-clobbered registers):
1673 (gdb) info registers rax
1676 Before, the former would print "<optimized out>", and the latter
1677 "*value not available*".
1679 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1684 ** Frame filters and frame decorators have been added.
1685 ** Temporary breakpoints are now supported.
1686 ** Line tables representation has been added.
1687 ** New attribute 'parent_type' for gdb.Field objects.
1688 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1689 ** New attribute 'name' for gdb.Type objects.
1693 Nios II ELF nios2*-*-elf
1694 Nios II GNU/Linux nios2*-*-linux
1695 Texas Instruments MSP430 msp430*-*-elf
1697 * Removed native configurations
1699 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1700 been removed. ELF variants of these configurations are kept supported.
1702 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1703 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1704 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1705 i[34567]86-*-openbsd3.[0-3]
1706 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1707 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1708 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1712 Like "catch throw", but catches a re-thrown exception.
1713 maint check-psymtabs
1714 Renamed from old "maint check-symtabs".
1716 Perform consistency checks on symtabs.
1717 maint expand-symtabs
1718 Expand symtabs matching an optional regexp.
1721 Display the details of GDB configure-time options.
1723 maint set|show per-command
1724 maint set|show per-command space
1725 maint set|show per-command time
1726 maint set|show per-command symtab
1727 Enable display of per-command gdb resource usage.
1729 remove-symbol-file FILENAME
1730 remove-symbol-file -a ADDRESS
1731 Remove a symbol file added via add-symbol-file. The file to remove
1732 can be identified by its filename or by an address that lies within
1733 the boundaries of this symbol file in memory.
1736 info exceptions REGEXP
1737 Display the list of Ada exceptions defined in the program being
1738 debugged. If provided, only the exceptions whose names match REGEXP
1743 set debug symfile off|on
1745 Control display of debugging info regarding reading symbol files and
1746 symbol tables within those files
1748 set print raw frame-arguments
1749 show print raw frame-arguments
1750 Set/show whether to print frame arguments in raw mode,
1751 disregarding any defined pretty-printers.
1753 set remote trace-status-packet
1754 show remote trace-status-packet
1755 Set/show the use of remote protocol qTStatus packet.
1759 Control display of debugging messages related to Nios II targets.
1763 Control whether target-assisted range stepping is enabled.
1765 set startup-with-shell
1766 show startup-with-shell
1767 Specifies whether Unix child processes are started via a shell or
1772 Use the target memory cache for accesses to the code segment. This
1773 improves performance of remote debugging (particularly disassembly).
1775 * You can now use a literal value 'unlimited' for options that
1776 interpret 0 or -1 as meaning "unlimited". E.g., "set
1777 trace-buffer-size unlimited" is now an alias for "set
1778 trace-buffer-size -1" and "set height unlimited" is now an alias for
1781 * The "set debug symtab-create" debugging option of GDB has been changed to
1782 accept a verbosity level. 0 means "off", 1 provides basic debugging
1783 output, and values of 2 or greater provides more verbose output.
1785 * New command-line options
1787 Display the details of GDB configure-time options.
1789 * The command 'tsave' can now support new option '-ctf' to save trace
1790 buffer in Common Trace Format.
1792 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1795 * GDB now implements the the C++ 'typeid' operator.
1797 * The new convenience variable $_exception holds the exception being
1798 thrown or caught at an exception-related catchpoint.
1800 * The exception-related catchpoints, like "catch throw", now accept a
1801 regular expression which can be used to filter exceptions by type.
1803 * The new convenience variable $_exitsignal is automatically set to
1804 the terminating signal number when the program being debugged dies
1805 due to an uncaught signal.
1809 ** All MI commands now accept an optional "--language" option.
1810 Support for this feature can be verified by using the "-list-features"
1811 command, which should contain "language-option".
1813 ** The new command -info-gdb-mi-command allows the user to determine
1814 whether a GDB/MI command is supported or not.
1816 ** The "^error" result record returned when trying to execute an undefined
1817 GDB/MI command now provides a variable named "code" whose content is the
1818 "undefined-command" error code. Support for this feature can be verified
1819 by using the "-list-features" command, which should contain
1820 "undefined-command-error-code".
1822 ** The -trace-save MI command can optionally save trace buffer in Common
1825 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1827 ** The command -data-list-register-values now accepts an optional
1828 "--skip-unavailable" option. When used, only the available registers
1831 ** The new command -trace-frame-collected dumps collected variables,
1832 computed expressions, tvars, memory and registers in a traceframe.
1834 ** The commands -stack-list-locals, -stack-list-arguments and
1835 -stack-list-variables now accept an option "--skip-unavailable".
1836 When used, only the available locals or arguments are displayed.
1838 ** The -exec-run command now accepts an optional "--start" option.
1839 When used, the command follows the same semantics as the "start"
1840 command, stopping the program's execution at the start of its
1841 main subprogram. Support for this feature can be verified using
1842 the "-list-features" command, which should contain
1843 "exec-run-start-option".
1845 ** The new commands -catch-assert and -catch-exceptions insert
1846 catchpoints stopping the program when Ada exceptions are raised.
1848 ** The new command -info-ada-exceptions provides the equivalent of
1849 the new "info exceptions" command.
1851 * New system-wide configuration scripts
1852 A GDB installation now provides scripts suitable for use as system-wide
1853 configuration scripts for the following systems:
1857 * GDB now supports target-assigned range stepping with remote targets.
1858 This improves the performance of stepping source lines by reducing
1859 the number of control packets from/to GDB. See "New remote packets"
1862 * GDB now understands the element 'tvar' in the XML traceframe info.
1863 It has the id of the collected trace state variables.
1865 * On S/390 targets that provide the transactional-execution feature,
1866 the program interruption transaction diagnostic block (TDB) is now
1867 represented as a number of additional "registers" in GDB.
1869 * New remote packets
1873 The vCont packet supports a new 'r' action, that tells the remote
1874 stub to step through an address range itself, without GDB
1875 involvemement at each single-step.
1877 qXfer:libraries-svr4:read's annex
1878 The previously unused annex of the qXfer:libraries-svr4:read packet
1879 is now used to support passing an argument list. The remote stub
1880 reports support for this argument list to GDB's qSupported query.
1881 The defined arguments are "start" and "prev", used to reduce work
1882 necessary for library list updating, resulting in significant
1885 * New features in the GDB remote stub, GDBserver
1887 ** GDBserver now supports target-assisted range stepping. Currently
1888 enabled on x86/x86_64 GNU/Linux targets.
1890 ** GDBserver now adds element 'tvar' in the XML in the reply to
1891 'qXfer:traceframe-info:read'. It has the id of the collected
1892 trace state variables.
1894 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1897 * New 'z' formatter for printing and examining memory, this displays the
1898 value as hexadecimal zero padded on the left to the size of the type.
1900 * GDB can now use Windows x64 unwinding data.
1902 * The "set remotebaud" command has been replaced by "set serial baud".
1903 Similarly, "show remotebaud" has been replaced by "show serial baud".
1904 The "set remotebaud" and "show remotebaud" commands are still available
1905 to provide backward compatibility with older versions of GDB.
1907 *** Changes in GDB 7.6
1909 * Target record has been renamed to record-full.
1910 Record/replay is now enabled with the "record full" command.
1911 This also affects settings that are associated with full record/replay
1912 that have been moved from "set/show record" to "set/show record full":
1914 set|show record full insn-number-max
1915 set|show record full stop-at-limit
1916 set|show record full memory-query
1918 * A new record target "record-btrace" has been added. The new target
1919 uses hardware support to record the control-flow of a process. It
1920 does not support replaying the execution, but it implements the
1921 below new commands for investigating the recorded execution log.
1922 This new recording method can be enabled using:
1926 The "record-btrace" target is only available on Intel Atom processors
1927 and requires a Linux kernel 2.6.32 or later.
1929 * Two new commands have been added for record/replay to give information
1930 about the recorded execution without having to replay the execution.
1931 The commands are only supported by "record btrace".
1933 record instruction-history prints the execution history at
1934 instruction granularity
1936 record function-call-history prints the execution history at
1937 function granularity
1939 * New native configurations
1941 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1942 FreeBSD/powerpc powerpc*-*-freebsd
1943 x86_64/Cygwin x86_64-*-cygwin*
1944 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1948 ARM AArch64 aarch64*-*-elf
1949 ARM AArch64 GNU/Linux aarch64*-*-linux
1950 Lynx 178 PowerPC powerpc-*-lynx*178
1951 x86_64/Cygwin x86_64-*-cygwin*
1952 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1954 * If the configured location of system.gdbinit file (as given by the
1955 --with-system-gdbinit option at configure time) is in the
1956 data-directory (as specified by --with-gdb-datadir at configure
1957 time) or in one of its subdirectories, then GDB will look for the
1958 system-wide init file in the directory specified by the
1959 --data-directory command-line option.
1961 * New command line options:
1963 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1964 other initialization files, unlike -nx which disables all of them.
1966 * Removed command line options
1968 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1971 * The 'ptype' and 'whatis' commands now accept an argument to control
1974 * 'info proc' now works on some core files.
1978 ** Vectors can be created with gdb.Type.vector.
1980 ** Python's atexit.register now works in GDB.
1982 ** Types can be pretty-printed via a Python API.
1984 ** Python 3 is now supported (in addition to Python 2.4 or later)
1986 ** New class gdb.Architecture exposes GDB's internal representation
1987 of architecture in the Python API.
1989 ** New method Frame.architecture returns the gdb.Architecture object
1990 corresponding to the frame's architecture.
1992 * New Python-based convenience functions:
1994 ** $_memeq(buf1, buf2, length)
1995 ** $_streq(str1, str2)
1997 ** $_regex(str, regex)
1999 * The 'cd' command now defaults to using '~' (the home directory) if not
2002 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2003 default for GCC since November 2000.
2005 * The command 'forward-search' can now be abbreviated as 'fo'.
2007 * The command 'info tracepoints' can now display 'installed on target'
2008 or 'not installed on target' for each non-pending location of tracepoint.
2010 * New configure options
2012 --enable-libmcheck/--disable-libmcheck
2013 By default, development versions are built with -lmcheck on hosts
2014 that support it, in order to help track memory corruption issues.
2015 Release versions, on the other hand, are built without -lmcheck
2016 by default. The --enable-libmcheck/--disable-libmcheck configure
2017 options allow the user to override that default.
2018 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2019 This configure option allows the user to build GDB with
2020 libbabeltrace using which GDB can read Common Trace Format data.
2022 * New commands (for set/show, see "New options" below)
2025 Catch signals. This is similar to "handle", but allows commands and
2026 conditions to be attached.
2029 List the BFDs known to GDB.
2031 python-interactive [command]
2033 Start a Python interactive prompt, or evaluate the optional command
2034 and print the result of expressions.
2037 "py" is a new alias for "python".
2039 enable type-printer [name]...
2040 disable type-printer [name]...
2041 Enable or disable type printers.
2045 ** For the Renesas Super-H architecture, the "regs" command has been removed
2046 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2051 set print type methods (on|off)
2052 show print type methods
2053 Control whether method declarations are displayed by "ptype".
2054 The default is to show them.
2056 set print type typedefs (on|off)
2057 show print type typedefs
2058 Control whether typedef definitions are displayed by "ptype".
2059 The default is to show them.
2061 set filename-display basename|relative|absolute
2062 show filename-display
2063 Control the way in which filenames is displayed.
2064 The default is "relative", which preserves previous behavior.
2066 set trace-buffer-size
2067 show trace-buffer-size
2068 Request target to change the size of trace buffer.
2070 set remote trace-buffer-size-packet auto|on|off
2071 show remote trace-buffer-size-packet
2072 Control the use of the remote protocol `QTBuffer:size' packet.
2076 Control display of debugging messages related to ARM AArch64.
2079 set debug coff-pe-read
2080 show debug coff-pe-read
2081 Control display of debugging messages related to reading of COFF/PE
2086 Control display of debugging messages related to Mach-O symbols
2089 set debug notification
2090 show debug notification
2091 Control display of debugging info for async remote notification.
2095 ** Command parameter changes are now notified using new async record
2096 "=cmd-param-changed".
2097 ** Trace frame changes caused by command "tfind" are now notified using
2098 new async record "=traceframe-changed".
2099 ** The creation, deletion and modification of trace state variables
2100 are now notified using new async records "=tsv-created",
2101 "=tsv-deleted" and "=tsv-modified".
2102 ** The start and stop of process record are now notified using new
2103 async record "=record-started" and "=record-stopped".
2104 ** Memory changes are now notified using new async record
2106 ** The data-disassemble command response will include a "fullname" field
2107 containing the absolute file name when source has been requested.
2108 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2109 command, to allow pattern filling of memory areas.
2110 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2111 library load/unload events.
2112 ** The response to breakpoint commands and breakpoint async records
2113 includes an "installed" field containing a boolean state about each
2114 non-pending tracepoint location is whether installed on target or not.
2115 ** Output of the "-trace-status" command includes a "trace-file" field
2116 containing the name of the trace file being examined. This field is
2117 optional, and only present when examining a trace file.
2118 ** The "fullname" field is now always present along with the "file" field,
2119 even if the file cannot be found by GDB.
2121 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2122 You must have the LZMA library available when configuring GDB for this
2123 feature to be enabled. For more information, see:
2124 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2126 * New remote packets
2129 Set the size of trace buffer. The remote stub reports support for this
2130 packet to gdb's qSupported query.
2133 Enable Branch Trace Store (BTS)-based branch tracing for the current
2134 thread. The remote stub reports support for this packet to gdb's
2138 Disable branch tracing for the current thread. The remote stub reports
2139 support for this packet to gdb's qSupported query.
2142 Read the traced branches for the current thread. The remote stub
2143 reports support for this packet to gdb's qSupported query.
2145 *** Changes in GDB 7.5
2147 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2148 for more x32 ABI info.
2150 * GDB now supports access to MIPS DSP registers on Linux targets.
2152 * GDB now supports debugging microMIPS binaries.
2154 * The "info os" command on GNU/Linux can now display information on
2155 several new classes of objects managed by the operating system:
2156 "info os procgroups" lists process groups
2157 "info os files" lists file descriptors
2158 "info os sockets" lists internet-domain sockets
2159 "info os shm" lists shared-memory regions
2160 "info os semaphores" lists semaphores
2161 "info os msg" lists message queues
2162 "info os modules" lists loaded kernel modules
2164 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2165 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2166 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2167 options and inspect the probe arguments using the new $_probe_arg family
2168 of convenience variables. You can obtain more information about SystemTap
2169 in <http://sourceware.org/systemtap/>.
2171 * GDB now supports reversible debugging on ARM, it allows you to
2172 debug basic ARM and THUMB instructions, and provides
2173 record/replay support.
2175 * The option "symbol-reloading" has been deleted as it is no longer used.
2179 ** GDB commands implemented in Python can now be put in command class
2182 ** The "maint set python print-stack on|off" is now deleted.
2184 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2185 apply "flag enum"-style pretty-printing to any enum.
2187 ** gdb.lookup_symbol can now work when there is no current frame.
2189 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2190 the source at which the symbol was defined.
2192 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2193 method 'value'. The former indicates whether the symbol needs a
2194 frame in order to compute its value, and the latter computes the
2197 ** A new method 'referenced_value' on gdb.Value objects which can
2198 dereference pointer as well as C++ reference values.
2200 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2201 which return the global and static blocks (as gdb.Block objects),
2202 of the underlying symbol table, respectively.
2204 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2205 object associated with a PC value.
2207 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2208 of the address range occupied by code for the current source line.
2210 * Go language support.
2211 GDB now supports debugging programs written in the Go programming
2214 * GDBserver now supports stdio connections.
2215 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2217 * The binary "gdbtui" can no longer be built or installed.
2218 Use "gdb -tui" instead.
2220 * GDB will now print "flag" enums specially. A flag enum is one where
2221 all the enumerator values have no bits in common when pairwise
2222 "and"ed. When printing a value whose type is a flag enum, GDB will
2223 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2224 (gdb) print (enum E) 3
2227 * The filename part of a linespec will now match trailing components
2228 of a source file name. For example, "break gcc/expr.c:1000" will
2229 now set a breakpoint in build/gcc/expr.c, but not
2230 build/libcpp/expr.c.
2232 * The "info proc" and "generate-core-file" commands will now also
2233 work on remote targets connected to GDBserver on Linux.
2235 * The command "info catch" has been removed. It has been disabled
2236 since December 2007.
2238 * The "catch exception" and "catch assert" commands now accept
2239 a condition at the end of the command, much like the "break"
2240 command does. For instance:
2242 (gdb) catch exception Constraint_Error if Barrier = True
2244 Previously, it was possible to add a condition to such catchpoints,
2245 but it had to be done as a second step, after the catchpoint had been
2246 created, using the "condition" command.
2248 * The "info static-tracepoint-marker" command will now also work on
2249 native Linux targets with in-process agent.
2251 * GDB can now set breakpoints on inlined functions.
2253 * The .gdb_index section has been updated to include symbols for
2254 inlined functions. GDB will ignore older .gdb_index sections by
2255 default, which could cause symbol files to be loaded more slowly
2256 until their .gdb_index sections can be recreated. The new command
2257 "set use-deprecated-index-sections on" will cause GDB to use any older
2258 .gdb_index sections it finds. This will restore performance, but the
2259 ability to set breakpoints on inlined functions will be lost in symbol
2260 files with older .gdb_index sections.
2262 The .gdb_index section has also been updated to record more information
2263 about each symbol. This speeds up the "info variables", "info functions"
2264 and "info types" commands when used with programs having the .gdb_index
2265 section, as well as speeding up debugging with shared libraries using
2266 the .gdb_index section.
2268 * Ada support for GDB/MI Variable Objects has been added.
2270 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2275 ** New command -info-os is the MI equivalent of "info os".
2277 ** Output logs ("set logging" and related) now include MI output.
2281 ** "set use-deprecated-index-sections on|off"
2282 "show use-deprecated-index-sections on|off"
2283 Controls the use of deprecated .gdb_index sections.
2285 ** "catch load" and "catch unload" can be used to stop when a shared
2286 library is loaded or unloaded, respectively.
2288 ** "enable count" can be used to auto-disable a breakpoint after
2291 ** "info vtbl" can be used to show the virtual method tables for
2292 C++ and Java objects.
2294 ** "explore" and its sub commands "explore value" and "explore type"
2295 can be used to recursively explore values and types of
2296 expressions. These commands are available only if GDB is
2297 configured with '--with-python'.
2299 ** "info auto-load" shows status of all kinds of auto-loaded files,
2300 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2301 sequences of commands files, "info auto-load python-scripts"
2302 shows status of auto-loading Python script files,
2303 "info auto-load local-gdbinit" shows status of loading init file
2304 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2305 status of inferior specific thread debugging shared library loading.
2307 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2308 and "show auto-load-scripts" commands have been deprecated, use their
2309 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2310 and "show auto-load python-scripts" counterparts instead.
2312 ** "dprintf location,format,args..." creates a dynamic printf, which
2313 is basically a breakpoint that does a printf and immediately
2314 resumes your program's execution, so it is like a printf that you
2315 can insert dynamically at runtime instead of at compiletime.
2317 ** "set print symbol"
2319 Controls whether GDB attempts to display the symbol, if any,
2320 corresponding to addresses it prints. This defaults to "on", but
2321 you can set it to "off" to restore GDB's previous behavior.
2323 * Deprecated commands
2325 ** For the Renesas Super-H architecture, the "regs" command has been
2326 deprecated, and "info all-registers" should be used instead.
2330 Renesas RL78 rl78-*-elf
2331 HP OpenVMS ia64 ia64-hp-openvms*
2333 * GDBserver supports evaluation of breakpoint conditions. When
2334 support is advertised by GDBserver, GDB may be told to send the
2335 breakpoint conditions in bytecode form to GDBserver. GDBserver
2336 will only report the breakpoint trigger to GDB when its condition
2341 set mips compression
2342 show mips compression
2343 Select the compressed ISA encoding used in functions that have no symbol
2344 information available. The encoding can be set to either of:
2347 and is updated automatically from ELF file flags if available.
2349 set breakpoint condition-evaluation
2350 show breakpoint condition-evaluation
2351 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2352 GDBserver ("target"). Default option "auto" chooses the most efficient
2354 This option can improve debugger efficiency depending on the speed of the
2358 Disable auto-loading globally.
2361 Show auto-loading setting of all kinds of auto-loaded files.
2363 set auto-load gdb-scripts on|off
2364 show auto-load gdb-scripts
2365 Control auto-loading of GDB canned sequences of commands files.
2367 set auto-load python-scripts on|off
2368 show auto-load python-scripts
2369 Control auto-loading of Python script files.
2371 set auto-load local-gdbinit on|off
2372 show auto-load local-gdbinit
2373 Control loading of init file (.gdbinit) from current directory.
2375 set auto-load libthread-db on|off
2376 show auto-load libthread-db
2377 Control auto-loading of inferior specific thread debugging shared library.
2379 set auto-load scripts-directory <dir1>[:<dir2>...]
2380 show auto-load scripts-directory
2381 Set a list of directories from which to load auto-loaded scripts.
2382 Automatically loaded Python scripts and GDB scripts are located in one
2383 of the directories listed by this option.
2384 The delimiter (':' above) may differ according to the host platform.
2386 set auto-load safe-path <dir1>[:<dir2>...]
2387 show auto-load safe-path
2388 Set a list of directories from which it is safe to auto-load files.
2389 The delimiter (':' above) may differ according to the host platform.
2391 set debug auto-load on|off
2392 show debug auto-load
2393 Control display of debugging info for auto-loading the files above.
2395 set dprintf-style gdb|call|agent
2397 Control the way in which a dynamic printf is performed; "gdb"
2398 requests a GDB printf command, while "call" causes dprintf to call a
2399 function in the inferior. "agent" requests that the target agent
2400 (such as GDBserver) do the printing.
2402 set dprintf-function <expr>
2403 show dprintf-function
2404 set dprintf-channel <expr>
2405 show dprintf-channel
2406 Set the function and optional first argument to the call when using
2407 the "call" style of dynamic printf.
2409 set disconnected-dprintf on|off
2410 show disconnected-dprintf
2411 Control whether agent-style dynamic printfs continue to be in effect
2412 after GDB disconnects.
2414 * New configure options
2416 --with-auto-load-dir
2417 Configure default value for the 'set auto-load scripts-directory'
2418 setting above. It defaults to '$debugdir:$datadir/auto-load',
2419 $debugdir representing global debugging info directories (available
2420 via 'show debug-file-directory') and $datadir representing GDB's data
2421 directory (available via 'show data-directory').
2423 --with-auto-load-safe-path
2424 Configure default value for the 'set auto-load safe-path' setting
2425 above. It defaults to the --with-auto-load-dir setting.
2427 --without-auto-load-safe-path
2428 Set 'set auto-load safe-path' to '/', effectively disabling this
2431 * New remote packets
2433 z0/z1 conditional breakpoints extension
2435 The z0/z1 breakpoint insertion packets have been extended to carry
2436 a list of conditional expressions over to the remote stub depending on the
2437 condition evaluation mode. The use of this extension can be controlled
2438 via the "set remote conditional-breakpoints-packet" command.
2442 Specify the signals which the remote stub may pass to the debugged
2443 program without GDB involvement.
2445 * New command line options
2447 --init-command=FILE, -ix Like --command, -x but execute it
2448 before loading inferior.
2449 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2450 execute it before loading inferior.
2452 *** Changes in GDB 7.4
2454 * GDB now handles ambiguous linespecs more consistently; the existing
2455 FILE:LINE support has been expanded to other types of linespecs. A
2456 breakpoint will now be set on all matching locations in all
2457 inferiors, and locations will be added or removed according to
2460 * GDB now allows you to skip uninteresting functions and files when
2461 stepping with the "skip function" and "skip file" commands.
2463 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2464 and "show remote hardware-watchpoint-length-limit". These allows to
2465 set or show the maximum length limit (in bytes) of a remote
2466 target hardware watchpoint.
2468 This allows e.g. to use "unlimited" hardware watchpoints with the
2469 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2470 watchpoints are slower than real hardware watchpoints but are
2471 significantly faster than gdb software watchpoints.
2475 ** The register_pretty_printer function in module gdb.printing now takes
2476 an optional `replace' argument. If True, the new printer replaces any
2479 ** The "maint set python print-stack on|off" command has been
2480 deprecated and will be deleted in GDB 7.5.
2481 A new command: "set python print-stack none|full|message" has
2482 replaced it. Additionally, the default for "print-stack" is
2483 now "message", which just prints the error message without
2486 ** A prompt substitution hook (prompt_hook) is now available to the
2489 ** A new Python module, gdb.prompt has been added to the GDB Python
2490 modules library. This module provides functionality for
2491 escape sequences in prompts (used by set/show
2492 extended-prompt). These escape sequences are replaced by their
2493 corresponding value.
2495 ** Python commands and convenience-functions located in
2496 'data-directory'/python/gdb/command and
2497 'data-directory'/python/gdb/function are now automatically loaded
2500 ** Blocks now provide four new attributes. global_block and
2501 static_block will return the global and static blocks
2502 respectively. is_static and is_global are boolean attributes
2503 that indicate if the block is one of those two types.
2505 ** Symbols now provide the "type" attribute, the type of the symbol.
2507 ** The "gdb.breakpoint" function has been deprecated in favor of
2510 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2511 of a function. This class is based on the "finish" command
2512 available in the CLI.
2514 ** Type objects for struct and union types now allow access to
2515 the fields using standard Python dictionary (mapping) methods.
2516 For example, "some_type['myfield']" now works, as does
2517 "some_type.items()".
2519 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2522 ** A new function, "deep_items" has been added to the gdb.types
2523 module in the GDB Python modules library. This function returns
2524 an iterator over the fields of a struct or union type. Unlike
2525 the standard Python "iteritems" method, it will recursively traverse
2526 any anonymous fields.
2530 ** "*stopped" events can report several new "reason"s, such as
2533 ** Breakpoint changes are now notified using new async records, like
2534 "=breakpoint-modified".
2536 ** New command -ada-task-info.
2538 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2539 $sdir specifies the default system locations of shared libraries.
2540 $pdir specifies the directory where the libpthread used by the application
2543 GDB no longer looks in $sdir and $pdir after it has searched the directories
2544 mentioned in libthread-db-search-path. If you want to search those
2545 directories, they must be specified in libthread-db-search-path.
2546 The default value of libthread-db-search-path on GNU/Linux and Solaris
2547 systems is now "$sdir:$pdir".
2549 $pdir is not supported by gdbserver, it is currently ignored.
2550 $sdir is supported by gdbserver.
2552 * New configure option --with-iconv-bin.
2553 When using the internationalization support like the one in the GNU C
2554 library, GDB will invoke the "iconv" program to get a list of supported
2555 character sets. If this program lives in a non-standard location, one can
2556 use this option to specify where to find it.
2558 * When natively debugging programs on PowerPC BookE processors running
2559 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2560 watchpoints, which specify a mask in addition to an address to watch.
2561 The mask specifies that some bits of an address (the bits which are
2562 reset in the mask) should be ignored when matching the address accessed
2563 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2564 section in the user manual for more details.
2566 * The new option --once causes GDBserver to stop listening for connections once
2567 the first connection is made. The listening port used by GDBserver will
2568 become available after that.
2570 * New commands "info macros" and "alias" have been added.
2572 * New function parameters suffix @entry specifies value of function parameter
2573 at the time the function got called. Entry values are available only since
2579 "!" is now an alias of the "shell" command.
2580 Note that no space is needed between "!" and SHELL COMMAND.
2584 watch EXPRESSION mask MASK_VALUE
2585 The watch command now supports the mask argument which allows creation
2586 of masked watchpoints, if the current architecture supports this feature.
2588 info auto-load-scripts [REGEXP]
2589 This command was formerly named "maintenance print section-scripts".
2590 It is now generally useful and is no longer a maintenance-only command.
2592 info macro [-all] [--] MACRO
2593 The info macro command has new options `-all' and `--'. The first for
2594 printing all definitions of a macro. The second for explicitly specifying
2595 the end of arguments and the beginning of the macro name in case the macro
2596 name starts with a hyphen.
2598 collect[/s] EXPRESSIONS
2599 The tracepoint collect command now takes an optional modifier "/s"
2600 that directs it to dereference pointer-to-character types and
2601 collect the bytes of memory up to a zero byte. The behavior is
2602 similar to what you see when you use the regular print command on a
2603 string. An optional integer following the "/s" sets a bound on the
2604 number of bytes that will be collected.
2607 The trace start command now interprets any supplied arguments as a
2608 note to be recorded with the trace run, with an effect similar to
2609 setting the variable trace-notes.
2612 The trace stop command now interprets any arguments as a note to be
2613 mentioned along with the tstatus report that the trace was stopped
2614 with a command. The effect is similar to setting the variable
2617 * Tracepoints can now be enabled and disabled at any time after a trace
2618 experiment has been started using the standard "enable" and "disable"
2619 commands. It is now possible to start a trace experiment with no enabled
2620 tracepoints; GDB will display a warning, but will allow the experiment to
2621 begin, assuming that tracepoints will be enabled as needed while the trace
2624 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2625 locations with 4-byte instructions, when they were previously
2626 limited to locations with instructions of 5 bytes or longer.
2630 set debug dwarf2-read
2631 show debug dwarf2-read
2632 Turns on or off display of debugging messages related to reading
2633 DWARF debug info. The default is off.
2635 set debug symtab-create
2636 show debug symtab-create
2637 Turns on or off display of debugging messages related to symbol table
2638 creation. The default is off.
2641 show extended-prompt
2642 Set the GDB prompt, and allow escape sequences to be inserted to
2643 display miscellaneous information (see 'help set extended-prompt'
2644 for the list of sequences). This prompt (and any information
2645 accessed through the escape sequences) is updated every time the
2646 prompt is displayed.
2648 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2649 show print entry-values
2650 Set printing of frame argument values at function entry. In some cases
2651 GDB can determine the value of function argument which was passed by the
2652 function caller, even if the value was modified inside the called function.
2654 set debug entry-values
2655 show debug entry-values
2656 Control display of debugging info for determining frame argument values at
2657 function entry and virtual tail call frames.
2659 set basenames-may-differ
2660 show basenames-may-differ
2661 Set whether a source file may have multiple base names.
2662 (A "base name" is the name of a file with the directory part removed.
2663 Example: The base name of "/home/user/hello.c" is "hello.c".)
2664 If set, GDB will canonicalize file names (e.g., expand symlinks)
2665 before comparing them. Canonicalization is an expensive operation,
2666 but it allows the same file be known by more than one base name.
2667 If not set (the default), all source files are assumed to have just
2668 one base name, and gdb will do file name comparisons more efficiently.
2674 Set a user name and notes for the current and any future trace runs.
2675 This is useful for long-running and/or disconnected traces, to
2676 inform others (or yourself) as to who is running the trace, supply
2677 contact information, or otherwise explain what is going on.
2679 set trace-stop-notes
2680 show trace-stop-notes
2681 Set a note attached to the trace run, that is displayed when the
2682 trace has been stopped by a tstop command. This is useful for
2683 instance as an explanation, if you are stopping a trace run that was
2684 started by someone else.
2686 * New remote packets
2690 Dynamically enable a tracepoint in a started trace experiment.
2694 Dynamically disable a tracepoint in a started trace experiment.
2698 Set the user and notes of the trace run.
2702 Query the current status of a tracepoint.
2706 Query the minimum length of instruction at which a fast tracepoint may
2709 * Dcache size (number of lines) and line-size are now runtime-configurable
2710 via "set dcache line" and "set dcache line-size" commands.
2714 Texas Instruments TMS320C6x tic6x-*-*
2718 Renesas RL78 rl78-*-elf
2720 *** Changes in GDB 7.3.1
2722 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2724 *** Changes in GDB 7.3
2726 * GDB has a new command: "thread find [REGEXP]".
2727 It finds the thread id whose name, target id, or thread extra info
2728 matches the given regular expression.
2730 * The "catch syscall" command now works on mips*-linux* targets.
2732 * The -data-disassemble MI command now supports modes 2 and 3 for
2733 dumping the instruction opcodes.
2735 * New command line options
2737 -data-directory DIR Specify DIR as the "data-directory".
2738 This is mostly for testing purposes.
2740 * The "maint set python auto-load on|off" command has been renamed to
2741 "set auto-load-scripts on|off".
2743 * GDB has a new command: "set directories".
2744 It is like the "dir" command except that it replaces the
2745 source path list instead of augmenting it.
2747 * GDB now understands thread names.
2749 On GNU/Linux, "info threads" will display the thread name as set by
2750 prctl or pthread_setname_np.
2752 There is also a new command, "thread name", which can be used to
2753 assign a name internally for GDB to display.
2756 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2757 has been integrated into GDB.
2761 ** The function gdb.Write now accepts an optional keyword 'stream'.
2762 This keyword, when provided, will direct the output to either
2763 stdout, stderr, or GDB's logging output.
2765 ** Parameters can now be be sub-classed in Python, and in particular
2766 you may implement the get_set_doc and get_show_doc functions.
2767 This improves how Parameter set/show documentation is processed
2768 and allows for more dynamic content.
2770 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2771 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2772 have an is_valid method.
2774 ** Breakpoints can now be sub-classed in Python, and in particular
2775 you may implement a 'stop' function that is executed each time
2776 the inferior reaches that breakpoint.
2778 ** New function gdb.lookup_global_symbol looks up a global symbol.
2780 ** GDB values in Python are now callable if the value represents a
2781 function. For example, if 'some_value' represents a function that
2782 takes two integer parameters and returns a value, you can call
2783 that function like so:
2785 result = some_value (10,20)
2787 ** Module gdb.types has been added.
2788 It contains a collection of utilities for working with gdb.Types objects:
2789 get_basic_type, has_field, make_enum_dict.
2791 ** Module gdb.printing has been added.
2792 It contains utilities for writing and registering pretty-printers.
2793 New classes: PrettyPrinter, SubPrettyPrinter,
2794 RegexpCollectionPrettyPrinter.
2795 New function: register_pretty_printer.
2797 ** New commands "info pretty-printers", "enable pretty-printer" and
2798 "disable pretty-printer" have been added.
2800 ** gdb.parameter("directories") is now available.
2802 ** New function gdb.newest_frame returns the newest frame in the
2805 ** The gdb.InferiorThread class has a new "name" attribute. This
2806 holds the thread's name.
2808 ** Python Support for Inferior events.
2809 Python scripts can add observers to be notified of events
2810 occurring in the process being debugged.
2811 The following events are currently supported:
2812 - gdb.events.cont Continue event.
2813 - gdb.events.exited Inferior exited event.
2814 - gdb.events.stop Signal received, and Breakpoint hit events.
2818 ** GDB now puts template parameters in scope when debugging in an
2819 instantiation. For example, if you have:
2821 template<int X> int func (void) { return X; }
2823 then if you step into func<5>, "print X" will show "5". This
2824 feature requires proper debuginfo support from the compiler; it
2825 was added to GCC 4.5.
2827 ** The motion commands "next", "finish", "until", and "advance" now
2828 work better when exceptions are thrown. In particular, GDB will
2829 no longer lose control of the inferior; instead, the GDB will
2830 stop the inferior at the point at which the exception is caught.
2831 This functionality requires a change in the exception handling
2832 code that was introduced in GCC 4.5.
2834 * GDB now follows GCC's rules on accessing volatile objects when
2835 reading or writing target state during expression evaluation.
2836 One notable difference to prior behavior is that "print x = 0"
2837 no longer generates a read of x; the value of the assignment is
2838 now always taken directly from the value being assigned.
2840 * GDB now has some support for using labels in the program's source in
2841 linespecs. For instance, you can use "advance label" to continue
2842 execution to a label.
2844 * GDB now has support for reading and writing a new .gdb_index
2845 section. This section holds a fast index of DWARF debugging
2846 information and can be used to greatly speed up GDB startup and
2847 operation. See the documentation for `save gdb-index' for details.
2849 * The "watch" command now accepts an optional "-location" argument.
2850 When used, this causes GDB to watch the memory referred to by the
2851 expression. Such a watchpoint is never deleted due to it going out
2854 * GDB now supports thread debugging of core dumps on GNU/Linux.
2856 GDB now activates thread debugging using the libthread_db library
2857 when debugging GNU/Linux core dumps, similarly to when debugging
2858 live processes. As a result, when debugging a core dump file, GDB
2859 is now able to display pthread_t ids of threads. For example, "info
2860 threads" shows the same output as when debugging the process when it
2861 was live. In earlier releases, you'd see something like this:
2864 * 1 LWP 6780 main () at main.c:10
2866 While now you see this:
2869 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2871 It is also now possible to inspect TLS variables when debugging core
2874 When debugging a core dump generated on a machine other than the one
2875 used to run GDB, you may need to point GDB at the correct
2876 libthread_db library with the "set libthread-db-search-path"
2877 command. See the user manual for more details on this command.
2879 * When natively debugging programs on PowerPC BookE processors running
2880 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2881 which stop execution of the inferior whenever it executes an instruction
2882 at any address within the specified range. See the "PowerPC Embedded"
2883 section in the user manual for more details.
2885 * New features in the GDB remote stub, GDBserver
2887 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2888 and i686 LynxOS (version 5.x).
2890 ** GDBserver is now supported on Blackfin Linux.
2892 * New native configurations
2894 ia64 HP-UX ia64-*-hpux*
2898 Analog Devices, Inc. Blackfin Processor bfin-*
2900 * Ada task switching is now supported on sparc-elf targets when
2901 debugging a program using the Ravenscar Profile. For more information,
2902 see the "Tasking Support when using the Ravenscar Profile" section
2903 in the GDB user manual.
2905 * Guile support was removed.
2907 * New features in the GNU simulator
2909 ** The --map-info flag lists all known core mappings.
2911 ** CFI flashes may be simulated via the "cfi" device.
2913 *** Changes in GDB 7.2
2915 * Shared library support for remote targets by default
2917 When GDB is configured for a generic, non-OS specific target, like
2918 for example, --target=arm-eabi or one of the many *-*-elf targets,
2919 GDB now queries remote stubs for loaded shared libraries using the
2920 `qXfer:libraries:read' packet. Previously, shared library support
2921 was always disabled for such configurations.
2925 ** Argument Dependent Lookup (ADL)
2927 In C++ ADL lookup directs function search to the namespaces of its
2928 arguments even if the namespace has not been imported.
2938 Here the compiler will search for `foo' in the namespace of 'b'
2939 and find A::foo. GDB now supports this. This construct is commonly
2940 used in the Standard Template Library for operators.
2942 ** Improved User Defined Operator Support
2944 In addition to member operators, GDB now supports lookup of operators
2945 defined in a namespace and imported with a `using' directive, operators
2946 defined in the global scope, operators imported implicitly from an
2947 anonymous namespace, and the ADL operators mentioned in the previous
2949 GDB now also supports proper overload resolution for all the previously
2950 mentioned flavors of operators.
2952 ** static const class members
2954 Printing of static const class members that are initialized in the
2955 class definition has been fixed.
2957 * Windows Thread Information Block access.
2959 On Windows targets, GDB now supports displaying the Windows Thread
2960 Information Block (TIB) structure. This structure is visible either
2961 by using the new command `info w32 thread-information-block' or, by
2962 dereferencing the new convenience variable named `$_tlb', a
2963 thread-specific pointer to the TIB. This feature is also supported
2964 when remote debugging using GDBserver.
2966 * Static tracepoints
2968 Static tracepoints are calls in the user program into a tracing
2969 library. One such library is a port of the LTTng kernel tracer to
2970 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2971 When debugging with GDBserver, GDB now supports combining the GDB
2972 tracepoint machinery with such libraries. For example: the user can
2973 use GDB to probe a static tracepoint marker (a call from the user
2974 program into the tracing library) with the new "strace" command (see
2975 "New commands" below). This creates a "static tracepoint" in the
2976 breakpoint list, that can be manipulated with the same feature set
2977 as fast and regular tracepoints. E.g., collect registers, local and
2978 global variables, collect trace state variables, and define
2979 tracepoint conditions. In addition, the user can collect extra
2980 static tracepoint marker specific data, by collecting the new
2981 $_sdata internal variable. When analyzing the trace buffer, you can
2982 inspect $_sdata like any other variable available to GDB. For more
2983 information, see the "Tracepoints" chapter in GDB user manual. New
2984 remote packets have been defined to support static tracepoints, see
2985 the "New remote packets" section below.
2987 * Better reconstruction of tracepoints after disconnected tracing
2989 GDB will attempt to download the original source form of tracepoint
2990 definitions when starting a trace run, and then will upload these
2991 upon reconnection to the target, resulting in a more accurate
2992 reconstruction of the tracepoints that are in use on the target.
2996 You can now exercise direct control over the ways that GDB can
2997 affect your program. For instance, you can disallow the setting of
2998 breakpoints, so that the program can run continuously (assuming
2999 non-stop mode). In addition, the "observer" variable is available
3000 to switch all of the different controls; in observer mode, GDB
3001 cannot affect the target's behavior at all, which is useful for
3002 tasks like diagnosing live systems in the field.
3004 * The new convenience variable $_thread holds the number of the
3007 * New remote packets
3011 Return the address of the Windows Thread Information Block of a given thread.
3015 In response to several of the tracepoint packets, the target may now
3016 also respond with a number of intermediate `qRelocInsn' request
3017 packets before the final result packet, to have GDB handle
3018 relocating an instruction to execute at a different address. This
3019 is particularly useful for stubs that support fast tracepoints. GDB
3020 reports support for this feature in the qSupported packet.
3024 List static tracepoint markers in the target program.
3028 List static tracepoint markers at a given address in the target
3031 qXfer:statictrace:read
3033 Read the static trace data collected (by a `collect $_sdata'
3034 tracepoint action). The remote stub reports support for this packet
3035 to gdb's qSupported query.
3039 Send the current settings of GDB's permission flags.
3043 Send part of the source (textual) form of a tracepoint definition,
3044 which includes location, conditional, and action list.
3046 * The source command now accepts a -s option to force searching for the
3047 script in the source search path even if the script name specifies
3050 * New features in the GDB remote stub, GDBserver
3052 - GDBserver now support tracepoints (including fast tracepoints, and
3053 static tracepoints). The feature is currently supported by the
3054 i386-linux and amd64-linux builds. See the "Tracepoints support
3055 in gdbserver" section in the manual for more information.
3057 GDBserver JIT compiles the tracepoint's conditional agent
3058 expression bytecode into native code whenever possible for low
3059 overhead dynamic tracepoints conditionals. For such tracepoints,
3060 an expression that examines program state is evaluated when the
3061 tracepoint is reached, in order to determine whether to capture
3062 trace data. If the condition is simple and false, processing the
3063 tracepoint finishes very quickly and no data is gathered.
3065 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3066 for static tracepoints support.
3068 - GDBserver now supports x86_64 Windows 64-bit debugging.
3070 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3071 it understands register description.
3073 * The --batch flag now disables pagination and queries.
3075 * X86 general purpose registers
3077 GDB now supports reading/writing byte, word and double-word x86
3078 general purpose registers directly. This means you can use, say,
3079 $ah or $ax to refer, respectively, to the byte register AH and
3080 16-bit word register AX that are actually portions of the 32-bit
3081 register EAX or 64-bit register RAX.
3083 * The `commands' command now accepts a range of breakpoints to modify.
3084 A plain `commands' following a command that creates multiple
3085 breakpoints affects all the breakpoints set by that command. This
3086 applies to breakpoints set by `rbreak', and also applies when a
3087 single `break' command creates multiple breakpoints (e.g.,
3088 breakpoints on overloaded c++ functions).
3090 * The `rbreak' command now accepts a filename specification as part of
3091 its argument, limiting the functions selected by the regex to those
3092 in the specified file.
3094 * Support for remote debugging Windows and SymbianOS shared libraries
3095 from Unix hosts has been improved. Non Windows GDB builds now can
3096 understand target reported file names that follow MS-DOS based file
3097 system semantics, such as file names that include drive letters and
3098 use the backslash character as directory separator. This makes it
3099 possible to transparently use the "set sysroot" and "set
3100 solib-search-path" on Unix hosts to point as host copies of the
3101 target's shared libraries. See the new command "set
3102 target-file-system-kind" described below, and the "Commands to
3103 specify files" section in the user manual for more information.
3107 eval template, expressions...
3108 Convert the values of one or more expressions under the control
3109 of the string template to a command line, and call it.
3111 set target-file-system-kind unix|dos-based|auto
3112 show target-file-system-kind
3113 Set or show the assumed file system kind for target reported file
3116 save breakpoints <filename>
3117 Save all current breakpoint definitions to a file suitable for use
3118 in a later debugging session. To read the saved breakpoint
3119 definitions, use the `source' command.
3121 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3124 info static-tracepoint-markers
3125 Display information about static tracepoint markers in the target.
3127 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3128 Define a static tracepoint by probing a marker at the given
3129 function, line, address, or marker ID.
3133 Enable and disable observer mode.
3135 set may-write-registers on|off
3136 set may-write-memory on|off
3137 set may-insert-breakpoints on|off
3138 set may-insert-tracepoints on|off
3139 set may-insert-fast-tracepoints on|off
3140 set may-interrupt on|off
3141 Set individual permissions for GDB effects on the target. Note that
3142 some of these settings can have undesirable or surprising
3143 consequences, particularly when changed in the middle of a session.
3144 For instance, disabling the writing of memory can prevent
3145 breakpoints from being inserted, cause single-stepping to fail, or
3146 even crash your program, if you disable after breakpoints have been
3147 inserted. However, GDB should not crash.
3149 set record memory-query on|off
3150 show record memory-query
3151 Control whether to stop the inferior if memory changes caused
3152 by an instruction cannot be recorded.
3157 The disassemble command now supports "start,+length" form of two arguments.
3161 ** GDB now provides a new directory location, called the python directory,
3162 where Python scripts written for GDB can be installed. The location
3163 of that directory is <data-directory>/python, where <data-directory>
3164 is the GDB data directory. For more details, see section `Scripting
3165 GDB using Python' in the manual.
3167 ** The GDB Python API now has access to breakpoints, symbols, symbol
3168 tables, program spaces, inferiors, threads and frame's code blocks.
3169 Additionally, GDB Parameters can now be created from the API, and
3170 manipulated via set/show in the CLI.
3172 ** New functions gdb.target_charset, gdb.target_wide_charset,
3173 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3175 ** New exception gdb.GdbError.
3177 ** Pretty-printers are now also looked up in the current program space.
3179 ** Pretty-printers can now be individually enabled and disabled.
3181 ** GDB now looks for names of Python scripts to auto-load in a
3182 special section named `.debug_gdb_scripts', in addition to looking
3183 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3185 * Tracepoint actions were unified with breakpoint commands. In particular,
3186 there are no longer differences in "info break" output for breakpoints and
3187 tracepoints and the "commands" command can be used for both tracepoints and
3188 regular breakpoints.
3192 ARM Symbian arm*-*-symbianelf*
3194 * D language support.
3195 GDB now supports debugging programs written in the D programming
3198 * GDB now supports the extended ptrace interface for PowerPC which is
3199 available since Linux kernel version 2.6.34. This automatically enables
3200 any hardware breakpoints and additional hardware watchpoints available in
3201 the processor. The old ptrace interface exposes just one hardware
3202 watchpoint and no hardware breakpoints.
3204 * GDB is now able to use the Data Value Compare (DVC) register available on
3205 embedded PowerPC processors to implement in hardware simple watchpoint
3206 conditions of the form:
3208 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3210 This works in native GDB running on Linux kernels with the extended ptrace
3211 interface mentioned above.
3213 *** Changes in GDB 7.1
3217 ** Namespace Support
3219 GDB now supports importing of namespaces in C++. This enables the
3220 user to inspect variables from imported namespaces. Support for
3221 namepace aliasing has also been added. So, if a namespace is
3222 aliased in the current scope (e.g. namepace C=A; ) the user can
3223 print variables using the alias (e.g. (gdb) print C::x).
3227 All known bugs relating to the printing of virtual base class were
3228 fixed. It is now possible to call overloaded static methods using a
3233 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3234 and reinterpret_cast<> are now handled by the C++ expression parser.
3238 Xilinx MicroBlaze microblaze-*-*
3243 Xilinx MicroBlaze microblaze
3246 * Multi-program debugging.
3248 GDB now has support for multi-program (a.k.a. multi-executable or
3249 multi-exec) debugging. This allows for debugging multiple inferiors
3250 simultaneously each running a different program under the same GDB
3251 session. See "Debugging Multiple Inferiors and Programs" in the
3252 manual for more information. This implied some user visible changes
3253 in the multi-inferior support. For example, "info inferiors" now
3254 lists inferiors that are not running yet or that have exited
3255 already. See also "New commands" and "New options" below.
3257 * New tracing features
3259 GDB's tracepoint facility now includes several new features:
3261 ** Trace state variables
3263 GDB tracepoints now include support for trace state variables, which
3264 are variables managed by the target agent during a tracing
3265 experiment. They are useful for tracepoints that trigger each
3266 other, so for instance one tracepoint can count hits in a variable,
3267 and then a second tracepoint has a condition that is true when the
3268 count reaches a particular value. Trace state variables share the
3269 $-syntax of GDB convenience variables, and can appear in both
3270 tracepoint actions and condition expressions. Use the "tvariable"
3271 command to create, and "info tvariables" to view; see "Trace State
3272 Variables" in the manual for more detail.
3276 GDB now includes an option for defining fast tracepoints, which
3277 targets may implement more efficiently, such as by installing a jump
3278 into the target agent rather than a trap instruction. The resulting
3279 speedup can be by two orders of magnitude or more, although the
3280 tradeoff is that some program locations on some target architectures
3281 might not allow fast tracepoint installation, for instance if the
3282 instruction to be replaced is shorter than the jump. To request a
3283 fast tracepoint, use the "ftrace" command, with syntax identical to
3284 the regular trace command.
3286 ** Disconnected tracing
3288 It is now possible to detach GDB from the target while it is running
3289 a trace experiment, then reconnect later to see how the experiment
3290 is going. In addition, a new variable disconnected-tracing lets you
3291 tell the target agent whether to continue running a trace if the
3292 connection is lost unexpectedly.
3296 GDB now has the ability to save the trace buffer into a file, and
3297 then use that file as a target, similarly to you can do with
3298 corefiles. You can select trace frames, print data that was
3299 collected in them, and use tstatus to display the state of the
3300 tracing run at the moment that it was saved. To create a trace
3301 file, use "tsave <filename>", and to use it, do "target tfile
3304 ** Circular trace buffer
3306 You can ask the target agent to handle the trace buffer as a
3307 circular buffer, discarding the oldest trace frames to make room for
3308 newer ones, by setting circular-trace-buffer to on. This feature may
3309 not be available for all target agents.
3314 The disassemble command, when invoked with two arguments, now requires
3315 the arguments to be comma-separated.
3318 The info variables command now displays variable definitions. Files
3319 which only declare a variable are not shown.
3322 The source command is now capable of sourcing Python scripts.
3323 This feature is dependent on the debugger being build with Python
3326 Related to this enhancement is also the introduction of a new command
3327 "set script-extension" (see below).
3329 * New commands (for set/show, see "New options" below)
3331 record save [<FILENAME>]
3332 Save a file (in core file format) containing the process record
3333 execution log for replay debugging at a later time.
3335 record restore <FILENAME>
3336 Restore the process record execution log that was saved at an
3337 earlier time, for replay debugging.
3339 add-inferior [-copies <N>] [-exec <FILENAME>]
3342 clone-inferior [-copies <N>] [ID]
3343 Make a new inferior ready to execute the same program another
3344 inferior has loaded.
3349 maint info program-spaces
3350 List the program spaces loaded into GDB.
3352 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3353 show remote interrupt-sequence
3354 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3355 as the sequence to the remote target in order to interrupt the execution.
3356 Ctrl-C is a default. Some system prefers BREAK which is high level of
3357 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3358 Magic SysRq g. It is BREAK signal and character 'g'.
3360 set remote interrupt-on-connect [on | off]
3361 show remote interrupt-on-connect
3362 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3363 remote target when gdb connects to it. This is needed when you debug
3366 set remotebreak [on | off]
3368 Deprecated. Use "set/show remote interrupt-sequence" instead.
3370 tvariable $NAME [ = EXP ]
3371 Create or modify a trace state variable.
3374 List trace state variables and their values.
3376 delete tvariable $NAME ...
3377 Delete one or more trace state variables.
3380 Evaluate the given expressions without collecting anything into the
3381 trace buffer. (Valid in tracepoint actions only.)
3383 ftrace FN / FILE:LINE / *ADDR
3384 Define a fast tracepoint at the given function, line, or address.
3386 * New expression syntax
3388 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3389 GDB now parses 0b101010 identically with 42.
3393 set follow-exec-mode new|same
3394 show follow-exec-mode
3395 Control whether GDB reuses the same inferior across an exec call or
3396 creates a new one. This is useful to be able to restart the old
3397 executable after the inferior having done an exec call.
3399 set default-collect EXPR, ...
3400 show default-collect
3401 Define a list of expressions to be collected at each tracepoint.
3402 This is a useful way to ensure essential items are not overlooked,
3403 such as registers or a critical global variable.
3405 set disconnected-tracing
3406 show disconnected-tracing
3407 If set to 1, the target is instructed to continue tracing if it
3408 loses its connection to GDB. If 0, the target is to stop tracing
3411 set circular-trace-buffer
3412 show circular-trace-buffer
3413 If set to on, the target is instructed to use a circular trace buffer
3414 and discard the oldest trace frames instead of stopping the trace due
3415 to a full trace buffer. If set to off, the trace stops when the buffer
3416 fills up. Some targets may not support this.
3418 set script-extension off|soft|strict
3419 show script-extension
3420 If set to "off", the debugger does not perform any script language
3421 recognition, and all sourced files are assumed to be GDB scripts.
3422 If set to "soft" (the default), files are sourced according to
3423 filename extension, falling back to GDB scripts if the first
3425 If set to "strict", files are sourced according to filename extension.
3427 set ada trust-PAD-over-XVS on|off
3428 show ada trust-PAD-over-XVS
3429 If off, activate a workaround against a bug in the debugging information
3430 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3431 the GCC sources for more information about the GNAT encoding and
3432 PAD types in particular). It is always safe to set this option to
3433 off, but this introduces a slight performance penalty. The default
3436 * Python API Improvements
3438 ** GDB provides the new class gdb.LazyString. This is useful in
3439 some pretty-printing cases. The new method gdb.Value.lazy_string
3440 provides a simple way to create objects of this type.
3442 ** The fields returned by gdb.Type.fields now have an
3443 `is_base_class' attribute.
3445 ** The new method gdb.Type.range returns the range of an array type.
3447 ** The new method gdb.parse_and_eval can be used to parse and
3448 evaluate an expression.
3450 * New remote packets
3453 Define a trace state variable.
3456 Get the current value of a trace state variable.
3459 Set desired tracing behavior upon disconnection.
3462 Set the trace buffer to be linear or circular.
3465 Get data about the tracepoints currently in use.
3469 Process record now works correctly with hardware watchpoints.
3471 Multiple bug fixes have been made to the mips-irix port, making it
3472 much more reliable. In particular:
3473 - Debugging threaded applications is now possible again. Previously,
3474 GDB would hang while starting the program, or while waiting for
3475 the program to stop at a breakpoint.
3476 - Attaching to a running process no longer hangs.
3477 - An error occurring while loading a core file has been fixed.
3478 - Changing the value of the PC register now works again. This fixes
3479 problems observed when using the "jump" command, or when calling
3480 a function from GDB, or even when assigning a new value to $pc.
3481 - With the "finish" and "return" commands, the return value for functions
3482 returning a small array is now correctly printed.
3483 - It is now possible to break on shared library code which gets executed
3484 during a shared library init phase (code executed while executing
3485 their .init section). Previously, the breakpoint would have no effect.
3486 - GDB is now able to backtrace through the signal handler for
3487 non-threaded programs.
3489 PIE (Position Independent Executable) programs debugging is now supported.
3490 This includes debugging execution of PIC (Position Independent Code) shared
3491 libraries although for that, it should be possible to run such libraries as an
3494 *** Changes in GDB 7.0
3496 * GDB now has an interface for JIT compilation. Applications that
3497 dynamically generate code can create symbol files in memory and register
3498 them with GDB. For users, the feature should work transparently, and
3499 for JIT developers, the interface is documented in the GDB manual in the
3500 "JIT Compilation Interface" chapter.
3502 * Tracepoints may now be conditional. The syntax is as for
3503 breakpoints; either an "if" clause appended to the "trace" command,
3504 or the "condition" command is available. GDB sends the condition to
3505 the target for evaluation using the same bytecode format as is used
3506 for tracepoint actions.
3508 * The disassemble command now supports: an optional /r modifier, print the
3509 raw instructions in hex as well as in symbolic form, and an optional /m
3510 modifier to print mixed source+assembly.
3512 * Process record and replay
3514 In a architecture environment that supports ``process record and
3515 replay'', ``process record and replay'' target can record a log of
3516 the process execution, and replay it with both forward and reverse
3519 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3520 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3521 set execution-direction {forward|reverse}, for targets that support
3524 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3525 feature is available with a native GDB running on kernel version
3528 * GDB now has support for multi-byte and wide character sets on the
3529 target. Strings whose character type is wchar_t, char16_t, or
3530 char32_t are now correctly printed. GDB supports wide- and unicode-
3531 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3532 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3533 `printf'. This feature requires iconv to work properly; if your
3534 system does not have a working iconv, GDB can use GNU libiconv. See
3535 the installation instructions for more information.
3537 * GDB now supports automatic retrieval of shared library files from
3538 remote targets. To use this feature, specify a system root that begins
3539 with the `remote:' prefix, either via the `set sysroot' command or via
3540 the `--with-sysroot' configure-time option.
3542 * "info sharedlibrary" now takes an optional regex of libraries to show,
3543 and it now reports if a shared library has no debugging information.
3545 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3546 now complete on file names.
3548 * When completing in expressions, gdb will attempt to limit
3549 completions to allowable structure or union fields, where appropriate.
3550 For instance, consider:
3552 # struct example { int f1; double f2; };
3553 # struct example variable;
3556 If the user types TAB at the end of this command line, the available
3557 completions will be "f1" and "f2".
3559 * Inlined functions are now supported. They show up in backtraces, and
3560 the "step", "next", and "finish" commands handle them automatically.
3562 * GDB now supports the token-splicing (##) and stringification (#)
3563 operators when expanding macros. It also supports variable-arity
3566 * GDB now supports inspecting extra signal information, exported by
3567 the new $_siginfo convenience variable. The feature is currently
3568 implemented on linux ARM, i386 and amd64.
3570 * GDB can now display the VFP floating point registers and NEON vector
3571 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3572 can provide these registers (requires Linux 2.6.30 or later). Remote
3573 and simulator targets may also provide them.
3575 * New remote packets
3578 Search memory for a sequence of bytes.
3581 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3582 operation over reliable transport links. Use of this packet is
3583 controlled by the `set remote noack-packet' command.
3586 Kill the process with the specified process ID. Use this in preference
3587 to `k' when multiprocess protocol extensions are supported.
3590 Obtains additional operating system information
3594 Read or write additional signal information.
3596 * Removed remote protocol undocumented extension
3598 An undocumented extension to the remote protocol's `S' stop reply
3599 packet that permited the stub to pass a process id was removed.
3600 Remote servers should use the `T' stop reply packet instead.
3602 * GDB now supports multiple function calling conventions according to the
3603 DWARF-2 DW_AT_calling_convention function attribute.
3605 * The SH target utilizes the aforementioned change to distinguish between gcc
3606 and Renesas calling convention. It also adds the new CLI commands
3607 `set/show sh calling-convention'.
3609 * GDB can now read compressed debug sections, as produced by GNU gold
3610 with the --compress-debug-sections=zlib flag.
3612 * 64-bit core files are now supported on AIX.
3614 * Thread switching is now supported on Tru64.
3616 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3617 which will be allocated using malloc later in program execution.
3619 * The qXfer:libraries:read remote procotol packet now allows passing a
3620 list of section offsets.
3622 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3623 conditions handling signals delivered during attach or thread creation
3624 have also been fixed.
3626 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3627 From the user's standpoint, all unqualified instances of True and False
3628 are treated as the standard definitions, regardless of context.
3630 * GDB now parses C++ symbol and type names more flexibly. For
3633 template<typename T> class C { };
3636 GDB will now correctly handle all of:
3638 ptype C<char const *>
3639 ptype C<char const*>
3640 ptype C<const char *>
3641 ptype C<const char*>
3643 * New features in the GDB remote stub, gdbserver
3645 - The "--wrapper" command-line argument tells gdbserver to use a
3646 wrapper program to launch programs for debugging.
3648 - On PowerPC and S/390 targets, it is now possible to use a single
3649 gdbserver executable to debug both 32-bit and 64-bit programs.
3650 (This requires gdbserver itself to be built as a 64-bit executable.)
3652 - gdbserver uses the new noack protocol mode for TCP connections to
3653 reduce communications latency, if also supported and enabled in GDB.
3655 - Support for the sparc64-linux-gnu target is now included in
3658 - The amd64-linux build of gdbserver now supports debugging both
3659 32-bit and 64-bit programs.
3661 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3662 now support hardware watchpoints, and will use them automatically
3667 GDB now has support for scripting using Python. Whether this is
3668 available is determined at configure time.
3670 New GDB commands can now be written in Python.
3672 * Ada tasking support
3674 Ada tasks can now be inspected in GDB. The following commands have
3678 Print the list of Ada tasks.
3680 Print detailed information about task number N.
3682 Print the task number of the current task.
3684 Switch the context of debugging to task number N.
3686 * Support for user-defined prefixed commands. The "define" command can
3687 add new commands to existing prefixes, e.g. "target".
3689 * Multi-inferior, multi-process debugging.
3691 GDB now has generalized support for multi-inferior debugging. See
3692 "Debugging Multiple Inferiors" in the manual for more information.
3693 Although availability still depends on target support, the command
3694 set is more uniform now. The GNU/Linux specific multi-forks support
3695 has been migrated to this new framework. This implied some user
3696 visible changes; see "New commands" and also "Removed commands"
3699 * Target descriptions can now describe the target OS ABI. See the
3700 "Target Description Format" section in the user manual for more
3703 * Target descriptions can now describe "compatible" architectures
3704 to indicate that the target can execute applications for a different
3705 architecture in addition to those for the main target architecture.
3706 See the "Target Description Format" section in the user manual for
3709 * Multi-architecture debugging.
3711 GDB now includes general supports for debugging applications on
3712 hybrid systems that use more than one single processor architecture
3713 at the same time. Each such hybrid architecture still requires
3714 specific support to be added. The only hybrid architecture supported
3715 in this version of GDB is the Cell Broadband Engine.
3717 * GDB now supports integrated debugging of Cell/B.E. applications that
3718 use both the PPU and SPU architectures. To enable support for hybrid
3719 Cell/B.E. debugging, you need to configure GDB to support both the
3720 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3721 --enable-targets configure option.
3723 * Non-stop mode debugging.
3725 For some targets, GDB now supports an optional mode of operation in
3726 which you can examine stopped threads while other threads continue
3727 to execute freely. This is referred to as non-stop mode, with the
3728 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3729 section in the user manual for more information.
3731 To be able to support remote non-stop debugging, a remote stub needs
3732 to implement the non-stop mode remote protocol extensions, as
3733 described in the "Remote Non-Stop" section of the user manual. The
3734 GDB remote stub, gdbserver, has been adjusted to support these
3735 extensions on linux targets.
3737 * New commands (for set/show, see "New options" below)
3739 catch syscall [NAME(S) | NUMBER(S)]
3740 Catch system calls. Arguments, which should be names of system
3741 calls or their numbers, mean catch only those syscalls. Without
3742 arguments, every syscall will be caught. When the inferior issues
3743 any of the specified syscalls, GDB will stop and announce the system
3744 call, both when it is called and when its call returns. This
3745 feature is currently available with a native GDB running on the
3746 Linux Kernel, under the following architectures: x86, x86_64,
3747 PowerPC and PowerPC64.
3749 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3751 Search memory for a sequence of bytes.
3753 maint set python print-stack
3754 maint show python print-stack
3755 Show a stack trace when an error is encountered in a Python script.
3758 Invoke CODE by passing it to the Python interpreter.
3763 These allow macros to be defined, undefined, and listed
3767 Show operating system information about processes.
3770 List the inferiors currently under GDB's control.
3773 Switch focus to inferior number NUM.
3776 Detach from inferior number NUM.
3779 Kill inferior number NUM.
3783 set spu stop-on-load
3784 show spu stop-on-load
3785 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3787 set spu auto-flush-cache
3788 show spu auto-flush-cache
3789 Control whether to automatically flush the software-managed cache
3790 during Cell/B.E. debugging.
3792 set sh calling-convention
3793 show sh calling-convention
3794 Control the calling convention used when calling SH target functions.
3797 show debug timestamp
3798 Control display of timestamps with GDB debugging output.
3800 set disassemble-next-line
3801 show disassemble-next-line
3802 Control display of disassembled source lines or instructions when
3805 set remote noack-packet
3806 show remote noack-packet
3807 Set/show the use of remote protocol QStartNoAckMode packet. See above
3808 under "New remote packets."
3810 set remote query-attached-packet
3811 show remote query-attached-packet
3812 Control use of remote protocol `qAttached' (query-attached) packet.
3814 set remote read-siginfo-object
3815 show remote read-siginfo-object
3816 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3819 set remote write-siginfo-object
3820 show remote write-siginfo-object
3821 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3824 set remote reverse-continue
3825 show remote reverse-continue
3826 Control use of remote protocol 'bc' (reverse-continue) packet.
3828 set remote reverse-step
3829 show remote reverse-step
3830 Control use of remote protocol 'bs' (reverse-step) packet.
3832 set displaced-stepping
3833 show displaced-stepping
3834 Control displaced stepping mode. Displaced stepping is a way to
3835 single-step over breakpoints without removing them from the debuggee.
3836 Also known as "out-of-line single-stepping".
3839 show debug displaced
3840 Control display of debugging info for displaced stepping.
3842 maint set internal-error
3843 maint show internal-error
3844 Control what GDB does when an internal error is detected.
3846 maint set internal-warning
3847 maint show internal-warning
3848 Control what GDB does when an internal warning is detected.
3853 Use a wrapper program to launch programs for debugging.
3855 set multiple-symbols (all|ask|cancel)
3856 show multiple-symbols
3857 The value of this variable can be changed to adjust the debugger behavior
3858 when an expression or a breakpoint location contains an ambiguous symbol
3859 name (an overloaded function name, for instance).
3861 set breakpoint always-inserted
3862 show breakpoint always-inserted
3863 Keep breakpoints always inserted in the target, as opposed to inserting
3864 them when resuming the target, and removing them when the target stops.
3865 This option can improve debugger performance on slow remote targets.
3867 set arm fallback-mode (arm|thumb|auto)
3868 show arm fallback-mode
3869 set arm force-mode (arm|thumb|auto)
3871 These commands control how ARM GDB determines whether instructions
3872 are ARM or Thumb. The default for both settings is auto, which uses
3873 the current CPSR value for instructions without symbols; previous
3874 versions of GDB behaved as if "set arm fallback-mode arm".
3876 set disable-randomization
3877 show disable-randomization
3878 Standalone programs run with the virtual address space randomization enabled
3879 by default on some platforms. This option keeps the addresses stable across
3880 multiple debugging sessions.
3884 Control whether other threads are stopped or not when some thread hits
3889 Requests that asynchronous execution is enabled in the target, if available.
3890 In this case, it's possible to resume target in the background, and interact
3891 with GDB while the target is running. "show target-async" displays the
3892 current state of asynchronous execution of the target.
3894 set target-wide-charset
3895 show target-wide-charset
3896 The target-wide-charset is the name of the character set that GDB
3897 uses when printing characters whose type is wchar_t.
3899 set tcp auto-retry (on|off)
3901 set tcp connect-timeout
3902 show tcp connect-timeout
3903 These commands allow GDB to retry failed TCP connections to a remote stub
3904 with a specified timeout period; this is useful if the stub is launched
3905 in parallel with GDB but may not be ready to accept connections immediately.
3907 set libthread-db-search-path
3908 show libthread-db-search-path
3909 Control list of directories which GDB will search for appropriate
3912 set schedule-multiple (on|off)
3913 show schedule-multiple
3914 Allow GDB to resume all threads of all processes or only threads of
3915 the current process.
3919 Use more aggressive caching for accesses to the stack. This improves
3920 performance of remote debugging (particularly backtraces) without
3921 affecting correctness.
3923 set interactive-mode (on|off|auto)
3924 show interactive-mode
3925 Control whether GDB runs in interactive mode (on) or not (off).
3926 When in interactive mode, GDB waits for the user to answer all
3927 queries. Otherwise, GDB does not wait and assumes the default
3928 answer. When set to auto (the default), GDB determines which
3929 mode to use based on the stdin settings.
3934 For program forks, this is replaced by the new more generic `info
3935 inferiors' command. To list checkpoints, you can still use the
3936 `info checkpoints' command, which was an alias for the `info forks'
3940 Replaced by the new `inferior' command. To switch between
3941 checkpoints, you can still use the `restart' command, which was an
3942 alias for the `fork' command.
3945 This is removed, since some targets don't have a notion of
3946 processes. To switch between processes, you can still use the
3947 `inferior' command using GDB's own inferior number.
3950 For program forks, this is replaced by the new more generic `kill
3951 inferior' command. To delete a checkpoint, you can still use the
3952 `delete checkpoint' command, which was an alias for the `delete
3956 For program forks, this is replaced by the new more generic `detach
3957 inferior' command. To detach a checkpoint, you can still use the
3958 `detach checkpoint' command, which was an alias for the `detach
3961 * New native configurations
3963 x86/x86_64 Darwin i[34567]86-*-darwin*
3965 x86_64 MinGW x86_64-*-mingw*
3969 Lattice Mico32 lm32-*
3970 x86 DICOS i[34567]86-*-dicos*
3971 x86_64 DICOS x86_64-*-dicos*
3974 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3975 (mingw32ce) debugging.
3981 These commands were actually not implemented on any target.
3983 *** Changes in GDB 6.8
3985 * New native configurations
3987 NetBSD/hppa hppa*-*netbsd*
3988 Xtensa GNU/Linux xtensa*-*-linux*
3992 NetBSD/hppa hppa*-*-netbsd*
3993 Xtensa GNU/Lunux xtensa*-*-linux*
3995 * Change in command line behavior -- corefiles vs. process ids.
3997 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3998 attaching to process NUMBER fails, GDB no longer attempts to open a
3999 core file named NUMBER. Attaching to a program using the -c option
4000 is no longer supported. Instead, use the '-p' or '--pid' options.
4002 * GDB can now be built as a native debugger for debugging Windows x86
4003 (mingw32) Portable Executable (PE) programs.
4005 * Pending breakpoints no longer change their number when their address
4008 * GDB now supports breakpoints with multiple locations,
4009 including breakpoints on C++ constructors, inside C++ templates,
4010 and in inlined functions.
4012 * GDB's ability to debug optimized code has been improved. GDB more
4013 accurately identifies function bodies and lexical blocks that occupy
4014 more than one contiguous range of addresses.
4016 * Target descriptions can now describe registers for PowerPC.
4018 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4019 registers on PowerPC targets.
4021 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4022 targets even when the libthread_db library is not available.
4024 * The GDB remote stub, gdbserver, now supports the new file transfer
4025 commands (remote put, remote get, and remote delete).
4027 * The GDB remote stub, gdbserver, now supports run and attach in
4028 extended-remote mode.
4030 * hppa*64*-*-hpux11* target broken
4031 The debugger is unable to start a program and fails with the following
4032 error: "Error trying to get information about dynamic linker".
4033 The gdb-6.7 release is also affected.
4035 * GDB now supports the --enable-targets= configure option to allow
4036 building a single GDB executable that supports multiple remote
4037 target architectures.
4039 * GDB now supports debugging C and C++ programs which use the
4040 Decimal Floating Point extension. In addition, the PowerPC target
4041 now has a set of pseudo-registers to inspect decimal float values
4042 stored in two consecutive float registers.
4044 * The -break-insert MI command can optionally create pending
4047 * Improved support for debugging Ada
4048 Many improvements to the Ada language support have been made. These
4050 - Better support for Ada2005 interface types
4051 - Improved handling of arrays and slices in general
4052 - Better support for Taft-amendment types
4053 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4055 - Improved command completion in Ada
4058 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4063 set print frame-arguments (all|scalars|none)
4064 show print frame-arguments
4065 The value of this variable can be changed to control which argument
4066 values should be printed by the debugger when displaying a frame.
4071 Transfer files to and from a remote target, and delete remote files.
4078 Transfer files to and from a remote target, and delete remote files.
4080 * New remote packets
4087 Open, close, read, write, and delete files on the remote system.
4090 Attach to an existing process on the remote system, in extended-remote
4094 Run a new process on the remote system, in extended-remote mode.
4096 *** Changes in GDB 6.7
4098 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4099 bfd, libiberty and opcodes, as revealed by static analysis donated by
4100 Coverity, Inc. (http://scan.coverity.com).
4102 * When looking up multiply-defined global symbols, GDB will now prefer the
4103 symbol definition in the current shared library if it was built using the
4104 -Bsymbolic linker option.
4106 * When the Text User Interface (TUI) is not configured, GDB will now
4107 recognize the -tui command-line option and print a message that the TUI
4110 * The GDB remote stub, gdbserver, now has lower overhead for high
4111 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4113 * GDB for MIPS targets now autodetects whether a remote target provides
4114 32-bit or 64-bit register values.
4116 * Support for C++ member pointers has been improved.
4118 * GDB now understands XML target descriptions, which specify the
4119 target's overall architecture. GDB can read a description from
4120 a local file or over the remote serial protocol.
4122 * Vectors of single-byte data use a new integer type which is not
4123 automatically displayed as character or string data.
4125 * The /s format now works with the print command. It displays
4126 arrays of single-byte integers and pointers to single-byte integers
4129 * Target descriptions can now describe target-specific registers,
4130 for architectures which have implemented the support (currently
4131 only ARM, M68K, and MIPS).
4133 * GDB and the GDB remote stub, gdbserver, now support the XScale
4136 * The GDB remote stub, gdbserver, has been updated to support
4137 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4138 has been rewritten to use the standard GDB remote protocol.
4140 * GDB can now step into C++ functions which are called through thunks.
4142 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4144 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4145 layout. It also supports a TextSeg= and DataSeg= response when only
4146 segment base addresses (rather than offsets) are available.
4148 * The /i format now outputs any trailing branch delay slot instructions
4149 immediately following the last instruction within the count specified.
4151 * The GDB remote protocol "T" stop reply packet now supports a
4152 "library" response. Combined with the new "qXfer:libraries:read"
4153 packet, this response allows GDB to debug shared libraries on targets
4154 where the operating system manages the list of loaded libraries (e.g.
4155 Windows and SymbianOS).
4157 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4158 (DLLs) on Windows and Windows CE targets.
4160 * GDB now supports a faster verification that a .debug file matches its binary
4161 according to its build-id signature, if the signature is present.
4167 Enable or disable hardware flow control (RTS/CTS) on the serial port
4168 when debugging using remote targets.
4170 set mem inaccessible-by-default
4171 show mem inaccessible-by-default
4172 If the target supplies a memory map, for instance via the remote
4173 protocol's "qXfer:memory-map:read" packet, setting this variable
4174 prevents GDB from accessing memory outside the memory map. This
4175 is useful for targets with memory mapped registers or which react
4176 badly to accesses of unmapped address space.
4178 set breakpoint auto-hw
4179 show breakpoint auto-hw
4180 If the target supplies a memory map, for instance via the remote
4181 protocol's "qXfer:memory-map:read" packet, setting this variable
4182 lets GDB use hardware breakpoints automatically for memory regions
4183 where it can not use software breakpoints. This covers both the
4184 "break" command and internal breakpoints used for other commands
4185 including "next" and "finish".
4188 catch exception unhandled
4189 Stop the program execution when Ada exceptions are raised.
4192 Stop the program execution when an Ada assertion failed.
4196 Set an alternate system root for target files. This is a more
4197 general version of "set solib-absolute-prefix", which is now
4198 an alias to "set sysroot".
4201 Provide extended SPU facility status information. This set of
4202 commands is available only when debugging the Cell/B.E. SPU
4205 * New native configurations
4207 OpenBSD/sh sh*-*openbsd*
4210 unset tdesc filename
4212 Use the specified local file as an XML target description, and do
4213 not query the target for its built-in description.
4217 OpenBSD/sh sh*-*-openbsd*
4218 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4219 Toshiba Media Processor mep-elf
4221 * New remote packets
4224 Ignore the specified signals; pass them directly to the debugged program
4225 without stopping other threads or reporting them to GDB.
4227 qXfer:features:read:
4228 Read an XML target description from the target, which describes its
4233 Read or write contents of an spufs file on the target system. These
4234 packets are available only on the Cell/B.E. SPU architecture.
4236 qXfer:libraries:read:
4237 Report the loaded shared libraries. Combined with new "T" packet
4238 response, this packet allows GDB to debug shared libraries on
4239 targets where the operating system manages the list of loaded
4240 libraries (e.g. Windows and SymbianOS).
4244 Support for these obsolete configurations has been removed.
4252 i[34567]86-*-lynxos*
4253 i[34567]86-*-netware*
4254 i[34567]86-*-sco3.2v5*
4255 i[34567]86-*-sco3.2v4*
4257 i[34567]86-*-sysv4.2*
4260 i[34567]86-*-unixware2*
4261 i[34567]86-*-unixware*
4270 * Other removed features
4277 Various m68k-only ROM monitors.
4284 Various Renesas ROM monitors and debugging interfaces for SH and
4289 Support for a Macraigor serial interface to on-chip debugging.
4290 GDB does not directly support the newer parallel or USB
4295 A debug information format. The predecessor to DWARF 2 and
4296 DWARF 3, which are still supported.
4298 Support for the HP aCC compiler on HP-UX/PA-RISC
4300 SOM-encapsulated symbolic debugging information, automatic
4301 invocation of pxdb, and the aCC custom C++ ABI. This does not
4302 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4303 with aCC can still be debugged on an assembly level.
4305 MIPS ".pdr" sections
4307 A MIPS-specific format used to describe stack frame layout
4308 in debugging information.
4312 GDB could work with an older version of Guile to debug
4313 the interpreter and Scheme programs running in it.
4315 set mips stack-arg-size
4316 set mips saved-gpreg-size
4318 Use "set mips abi" to control parameter passing for MIPS.
4320 *** Changes in GDB 6.6
4325 Cell Broadband Engine SPU spu-elf
4327 * GDB can now be configured as a cross-debugger targeting native Windows
4328 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4329 running on a Windows system over TCP/IP to debug Windows programs.
4331 * The GDB remote stub, gdbserver, has been updated to support Windows and
4332 Cygwin debugging. Both single-threaded and multi-threaded programs are
4335 * The "set trust-readonly-sections" command works again. This command was
4336 broken in GDB 6.3, 6.4, and 6.5.
4338 * The "load" command now supports writing to flash memory, if the remote
4339 stub provides the required support.
4341 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4342 longer requires symbolic debug information (e.g. DWARF-2).
4347 unset substitute-path
4348 show substitute-path
4349 Manage a list of substitution rules that GDB uses to rewrite the name
4350 of the directories where the sources are located. This can be useful
4351 for instance when the sources were moved to a different location
4352 between compilation and debugging.
4356 Print each CLI command as it is executed. Each command is prefixed with
4357 a number of `+' symbols representing the nesting depth.
4358 The source command now has a `-v' option to enable the same feature.
4362 The ARM Demon monitor support (RDP protocol, "target rdp").
4364 Kernel Object Display, an embedded debugging feature which only worked with
4365 an obsolete version of Cisco IOS.
4367 The 'set download-write-size' and 'show download-write-size' commands.
4369 * New remote packets
4372 Tell a stub about GDB client features, and request remote target features.
4373 The first feature implemented is PacketSize, which allows the target to
4374 specify the size of packets it can handle - to minimize the number of
4375 packets required and improve performance when connected to a remote
4379 Fetch an OS auxilliary vector from the remote stub. This packet is a
4380 more efficient replacement for qPart:auxv:read.
4382 qXfer:memory-map:read:
4383 Fetch a memory map from the remote stub, including information about
4384 RAM, ROM, and flash memory devices.
4389 Erase and program a flash memory device.
4391 * Removed remote packets
4394 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4395 used it, and only gdbserver implemented it.
4397 *** Changes in GDB 6.5
4401 Renesas M32C/M16C m32c-elf
4403 Morpho Technologies ms1 ms1-elf
4407 init-if-undefined Initialize a convenience variable, but
4408 only if it doesn't already have a value.
4410 The following commands are presently only implemented for native GNU/Linux:
4412 checkpoint Save a snapshot of the program state.
4414 restart <n> Return the program state to a
4415 previously saved state.
4417 info checkpoints List currently saved checkpoints.
4419 delete-checkpoint <n> Delete a previously saved checkpoint.
4421 set|show detach-on-fork Tell gdb whether to detach from a newly
4422 forked process, or to keep debugging it.
4424 info forks List forks of the user program that
4425 are available to be debugged.
4427 fork <n> Switch to debugging one of several
4428 forks of the user program that are
4429 available to be debugged.
4431 delete-fork <n> Delete a fork from the list of forks
4432 that are available to be debugged (and
4433 kill the forked process).
4435 detach-fork <n> Delete a fork from the list of forks
4436 that are available to be debugged (and
4437 allow the process to continue).
4441 Morpho Technologies ms2 ms1-elf
4443 * Improved Windows host support
4445 GDB now builds as a cross debugger hosted on i686-mingw32, including
4446 native console support, and remote communications using either
4447 network sockets or serial ports.
4449 * Improved Modula-2 language support
4451 GDB can now print most types in the Modula-2 syntax. This includes:
4452 basic types, set types, record types, enumerated types, range types,
4453 pointer types and ARRAY types. Procedure var parameters are correctly
4454 printed and hexadecimal addresses and character constants are also
4455 written in the Modula-2 syntax. Best results can be obtained by using
4456 GNU Modula-2 together with the -gdwarf-2 command line option.
4460 The ARM rdi-share module.
4462 The Netware NLM debug server.
4464 *** Changes in GDB 6.4
4466 * New native configurations
4468 OpenBSD/arm arm*-*-openbsd*
4469 OpenBSD/mips64 mips64-*-openbsd*
4473 Morpho Technologies ms1 ms1-elf
4475 * New command line options
4477 --batch-silent As for --batch, but totally silent.
4478 --return-child-result The debugger will exist with the same value
4479 the child (debugged) program exited with.
4480 --eval-command COMMAND, -ex COMMAND
4481 Execute a single GDB CLI command. This may be
4482 specified multiple times and in conjunction
4483 with the --command (-x) option.
4485 * Deprecated commands removed
4487 The following commands, that were deprecated in 2000, have been
4491 set|show arm disassembly-flavor set|show arm disassembler
4492 othernames set arm disassembler
4493 set|show remotedebug set|show debug remote
4494 set|show archdebug set|show debug arch
4495 set|show eventdebug set|show debug event
4498 * New BSD user-level threads support
4500 It is now possible to debug programs using the user-level threads
4501 library on OpenBSD and FreeBSD. Currently supported (target)
4504 FreeBSD/amd64 x86_64-*-freebsd*
4505 FreeBSD/i386 i386-*-freebsd*
4506 OpenBSD/i386 i386-*-openbsd*
4508 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4509 are not yet supported.
4511 * New support for Matsushita MN10300 w/sim added
4512 (Work in progress). mn10300-elf.
4514 * REMOVED configurations and files
4516 VxWorks and the XDR protocol *-*-vxworks
4517 Motorola MCORE mcore-*-*
4518 National Semiconductor NS32000 ns32k-*-*
4520 * New "set print array-indexes" command
4522 After turning this setting "on", GDB prints the index of each element
4523 when displaying arrays. The default is "off" to preserve the previous
4526 * VAX floating point support
4528 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4530 * User-defined command support
4532 In addition to using $arg0..$arg9 for argument passing, it is now possible
4533 to use $argc to determine now many arguments have been passed. See the
4534 section on user-defined commands in the user manual for more information.
4536 *** Changes in GDB 6.3:
4538 * New command line option
4540 GDB now accepts -l followed by a number to set the timeout for remote
4543 * GDB works with GCC -feliminate-dwarf2-dups
4545 GDB now supports a more compact representation of DWARF-2 debug
4546 information using DW_FORM_ref_addr references. These are produced
4547 by GCC with the option -feliminate-dwarf2-dups and also by some
4548 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4549 to use -feliminate-dwarf2-dups.
4551 * Internationalization
4553 When supported by the host system, GDB will be built with
4554 internationalization (libintl). The task of marking up the sources is
4555 continued, we're looking forward to our first translation.
4559 Initial support for debugging programs compiled with the GNAT
4560 implementation of the Ada programming language has been integrated
4561 into GDB. In this release, support is limited to expression evaluation.
4563 * New native configurations
4565 GNU/Linux/m32r m32r-*-linux-gnu
4569 GDB's remote protocol now includes support for the 'p' packet. This
4570 packet is used to fetch individual registers from a remote inferior.
4572 * END-OF-LIFE registers[] compatibility module
4574 GDB's internal register infrastructure has been completely rewritten.
4575 The new infrastructure making possible the implementation of key new
4576 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4579 GDB 6.3 will be the last release to include the the registers[]
4580 compatibility module that allowed out-of-date configurations to
4581 continue to work. This change directly impacts the following
4591 powerpc bdm protocol
4593 Unless there is activity to revive these configurations, they will be
4594 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4596 * OBSOLETE configurations and files
4598 Configurations that have been declared obsolete in this release have
4599 been commented out. Unless there is activity to revive these
4600 configurations, the next release of GDB will have their sources
4601 permanently REMOVED.
4610 *** Changes in GDB 6.2.1:
4612 * MIPS `break main; run' gave an heuristic-fence-post warning
4614 When attempting to run even a simple program, a warning about
4615 heuristic-fence-post being hit would be reported. This problem has
4618 * MIPS IRIX 'long double' crashed GDB
4620 When examining a long double variable, GDB would get a segmentation
4621 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4622 IRIX long double values).
4626 A bug in the VAX stack code was causing problems with the "next"
4627 command. This problem has been fixed.
4629 *** Changes in GDB 6.2:
4631 * Fix for ``many threads''
4633 On GNU/Linux systems that use the NPTL threads library, a program
4634 rapidly creating and deleting threads would confuse GDB leading to the
4637 ptrace: No such process.
4638 thread_db_get_info: cannot get thread info: generic error
4640 This problem has been fixed.
4642 * "-async" and "-noasync" options removed.
4644 Support for the broken "-noasync" option has been removed (it caused
4647 * New ``start'' command.
4649 This command runs the program until the begining of the main procedure.
4651 * New BSD Kernel Data Access Library (libkvm) interface
4653 Using ``target kvm'' it is now possible to debug kernel core dumps and
4654 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4655 platforms. Currently supported (native-only) configurations are:
4657 FreeBSD/amd64 x86_64-*-freebsd*
4658 FreeBSD/i386 i?86-*-freebsd*
4659 NetBSD/i386 i?86-*-netbsd*
4660 NetBSD/m68k m68*-*-netbsd*
4661 NetBSD/sparc sparc-*-netbsd*
4662 OpenBSD/amd64 x86_64-*-openbsd*
4663 OpenBSD/i386 i?86-*-openbsd*
4664 OpenBSD/m68k m68*-openbsd*
4665 OpenBSD/sparc sparc-*-openbsd*
4667 * Signal trampoline code overhauled
4669 Many generic problems with GDB's signal handling code have been fixed.
4670 These include: backtraces through non-contiguous stacks; recognition
4671 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4672 call; backtrace through a signal trampoline; step into and out of
4673 signal handlers; and single-stepping in the signal trampoline.
4675 Please note that kernel bugs are a limiting factor here. These
4676 features have been shown to work on an s390 GNU/Linux system that
4677 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4679 * Cygwin support for DWARF 2 added.
4681 * New native configurations
4683 GNU/Linux/hppa hppa*-*-linux*
4684 OpenBSD/hppa hppa*-*-openbsd*
4685 OpenBSD/m68k m68*-*-openbsd*
4686 OpenBSD/m88k m88*-*-openbsd*
4687 OpenBSD/powerpc powerpc-*-openbsd*
4688 NetBSD/vax vax-*-netbsd*
4689 OpenBSD/vax vax-*-openbsd*
4691 * END-OF-LIFE frame compatibility module
4693 GDB's internal frame infrastructure has been completely rewritten.
4694 The new infrastructure making it possible to support key new features
4695 including DWARF 2 Call Frame Information. To aid in the task of
4696 migrating old configurations to this new infrastructure, a
4697 compatibility module, that allowed old configurations to continue to
4698 work, was also included.
4700 GDB 6.2 will be the last release to include this frame compatibility
4701 module. This change directly impacts the following configurations:
4711 Unless there is activity to revive these configurations, they will be
4712 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4714 * REMOVED configurations and files
4716 Sun 3, running SunOS 3 m68*-*-sunos3*
4717 Sun 3, running SunOS 4 m68*-*-sunos4*
4718 Sun 2, running SunOS 3 m68000-*-sunos3*
4719 Sun 2, running SunOS 4 m68000-*-sunos4*
4720 Motorola 680x0 running LynxOS m68*-*-lynxos*
4721 AT&T 3b1/Unix pc m68*-att-*
4722 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4723 decstation mips-dec-* mips-little-*
4724 riscos mips-*-riscos* mips-*-sysv*
4725 sonymips mips-sony-*
4726 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4728 *** Changes in GDB 6.1.1:
4730 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4732 The TUI (Text-mode User Interface) is now built as part of a default
4733 GDB configuration. It is enabled by either selecting the TUI with the
4734 command line option "-i=tui" or by running the separate "gdbtui"
4735 program. For more information on the TUI, see the manual "Debugging
4738 * Pending breakpoint support (also included in GDB 6.1)
4740 Support has been added to allow you to specify breakpoints in shared
4741 libraries that have not yet been loaded. If a breakpoint location
4742 cannot be found, and the "breakpoint pending" option is set to auto,
4743 GDB queries you if you wish to make the breakpoint pending on a future
4744 shared-library load. If and when GDB resolves the breakpoint symbol,
4745 the pending breakpoint is removed as one or more regular breakpoints
4748 Pending breakpoints are very useful for GCJ Java debugging.
4750 * Fixed ISO-C build problems
4752 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4753 non ISO-C code that stopped them being built using a more strict ISO-C
4754 compiler (e.g., IBM's C compiler).
4756 * Fixed build problem on IRIX 5
4758 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4759 wasn't able to compile compile on an IRIX 5 system.
4761 * Added execute permission to gdb/gdbserver/configure
4763 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4764 permission. This bug would cause configure to fail on a number of
4765 systems (Solaris, IRIX). Ref: server/519.
4767 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4769 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4770 has been updated to use constant array sizes.
4772 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4774 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4775 its generated DWARF Call Frame Info. This encoding was causing GDB to
4776 panic, that panic has been fixed. Ref: gdb/1628.
4778 * Fixed a problem when examining parameters in shared library code.
4780 When examining parameters in optimized shared library code generated
4781 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4782 not available''. GDB now correctly displays the variable's value.
4784 *** Changes in GDB 6.1:
4786 * Removed --with-mmalloc
4788 Support for the mmalloc memory manager has been removed, as it
4789 conflicted with the internal gdb byte cache.
4791 * Changes in AMD64 configurations
4793 The AMD64 target now includes the %cs and %ss registers. As a result
4794 the AMD64 remote protocol has changed; this affects the floating-point
4795 and SSE registers. If you rely on those registers for your debugging,
4796 you should upgrade gdbserver on the remote side.
4798 * Revised SPARC target
4800 The SPARC target has been completely revised, incorporating the
4801 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4802 support for LynxOS and SunOS 4 has been dropped. Calling functions
4803 from within GDB on operating systems with a non-executable stack
4804 (Solaris, OpenBSD) now works.
4808 GDB has a new C++ demangler which does a better job on the mangled
4809 names generated by current versions of g++. It also runs faster, so
4810 with this and other changes gdb should now start faster on large C++
4813 * DWARF 2 Location Expressions
4815 GDB support for location expressions has been extended to support function
4816 arguments and frame bases. Older versions of GDB could crash when they
4819 * C++ nested types and namespaces
4821 GDB's support for nested types and namespaces in C++ has been
4822 improved, especially if you use the DWARF 2 debugging format. (This
4823 is the default for recent versions of GCC on most platforms.)
4824 Specifically, if you have a class "Inner" defined within a class or
4825 namespace "Outer", then GDB realizes that the class's name is
4826 "Outer::Inner", not simply "Inner". This should greatly reduce the
4827 frequency of complaints about not finding RTTI symbols. In addition,
4828 if you are stopped at inside of a function defined within a namespace,
4829 GDB modifies its name lookup accordingly.
4831 * New native configurations
4833 NetBSD/amd64 x86_64-*-netbsd*
4834 OpenBSD/amd64 x86_64-*-openbsd*
4835 OpenBSD/alpha alpha*-*-openbsd*
4836 OpenBSD/sparc sparc-*-openbsd*
4837 OpenBSD/sparc64 sparc64-*-openbsd*
4839 * New debugging protocols
4841 M32R with SDI protocol m32r-*-elf*
4843 * "set prompt-escape-char" command deleted.
4845 The command "set prompt-escape-char" has been deleted. This command,
4846 and its very obscure effet on GDB's prompt, was never documented,
4847 tested, nor mentioned in the NEWS file.
4849 * OBSOLETE configurations and files
4851 Configurations that have been declared obsolete in this release have
4852 been commented out. Unless there is activity to revive these
4853 configurations, the next release of GDB will have their sources
4854 permanently REMOVED.
4856 Sun 3, running SunOS 3 m68*-*-sunos3*
4857 Sun 3, running SunOS 4 m68*-*-sunos4*
4858 Sun 2, running SunOS 3 m68000-*-sunos3*
4859 Sun 2, running SunOS 4 m68000-*-sunos4*
4860 Motorola 680x0 running LynxOS m68*-*-lynxos*
4861 AT&T 3b1/Unix pc m68*-att-*
4862 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4863 decstation mips-dec-* mips-little-*
4864 riscos mips-*-riscos* mips-*-sysv*
4865 sonymips mips-sony-*
4866 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4868 * REMOVED configurations and files
4870 SGI Irix-4.x mips-sgi-irix4 or iris4
4871 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4872 Z8000 simulator z8k-zilog-none or z8ksim
4873 Matsushita MN10200 w/simulator mn10200-*-*
4874 H8/500 simulator h8500-hitachi-hms or h8500hms
4875 HP/PA running BSD hppa*-*-bsd*
4876 HP/PA running OSF/1 hppa*-*-osf*
4877 HP/PA Pro target hppa*-*-pro*
4878 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4879 386BSD i[3456]86-*-bsd*
4880 Sequent family i[3456]86-sequent-sysv4*
4881 i[3456]86-sequent-sysv*
4882 i[3456]86-sequent-bsd*
4883 SPARC running LynxOS sparc-*-lynxos*
4884 SPARC running SunOS 4 sparc-*-sunos4*
4885 Tsqware Sparclet sparclet-*-*
4886 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4888 *** Changes in GDB 6.0:
4892 Support for debugging the Objective-C programming language has been
4893 integrated into GDB.
4895 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4897 DWARF 2's Call Frame Information makes available compiler generated
4898 information that more exactly describes the program's run-time stack.
4899 By using this information, GDB is able to provide more robust stack
4902 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4903 have been updated to use a new backtrace mechanism which includes
4904 DWARF 2 CFI support.
4908 GDB's remote protocol has been extended to include support for hosted
4909 file I/O (where the remote target uses GDB's file system). See GDB's
4910 remote protocol documentation for details.
4912 * All targets using the new architecture framework.
4914 All of GDB's targets have been updated to use the new internal
4915 architecture framework. The way is now open for future GDB releases
4916 to include cross-architecture native debugging support (i386 on amd64,
4919 * GNU/Linux's Thread Local Storage (TLS)
4921 GDB now includes support for for the GNU/Linux implementation of
4922 per-thread variables.
4924 * GNU/Linux's Native POSIX Thread Library (NPTL)
4926 GDB's thread code has been updated to work with either the new
4927 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4929 * Separate debug info.
4931 GDB, in conjunction with BINUTILS, now supports a mechanism for
4932 automatically loading debug information from a separate file. Instead
4933 of shipping full debug and non-debug versions of system libraries,
4934 system integrators can now instead ship just the stripped libraries
4935 and optional debug files.
4937 * DWARF 2 Location Expressions
4939 DWARF 2 Location Expressions allow the compiler to more completely
4940 describe the location of variables (even in optimized code) to the
4943 GDB now includes preliminary support for location expressions (support
4944 for DW_OP_piece is still missing).
4948 A number of long standing bugs that caused GDB to die while starting a
4949 Java application have been fixed. GDB's Java support is now
4950 considered "useable".
4952 * GNU/Linux support for fork, vfork, and exec.
4954 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4955 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4958 * GDB supports logging output to a file
4960 There are two new commands, "set logging" and "show logging", which can be
4961 used to capture GDB's output to a file.
4963 * The meaning of "detach" has changed for gdbserver
4965 The "detach" command will now resume the application, as documented. To
4966 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4969 * d10v, m68hc11 `regs' command deprecated
4971 The `info registers' command has been updated so that it displays the
4972 registers using a format identical to the old `regs' command.
4976 A new command, "maint set profile on/off", has been added. This command can
4977 be used to enable or disable profiling while running GDB, to profile a
4978 session or a set of commands. In addition there is a new configure switch,
4979 "--enable-profiling", which will cause GDB to be compiled with profiling
4980 data, for more informative profiling results.
4982 * Default MI syntax changed to "mi2".
4984 The default MI (machine interface) syntax, enabled by the command line
4985 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4986 "mi1", can be enabled by specifying the option "-i=mi1".
4988 Support for the original "mi0" syntax (included in GDB 5.0) has been
4991 Fix for gdb/192: removed extraneous space when displaying frame level.
4992 Fix for gdb/672: update changelist is now output in mi list format.
4993 Fix for gdb/702: a -var-assign that updates the value now shows up
4994 in a subsequent -var-update.
4996 * New native configurations.
4998 FreeBSD/amd64 x86_64-*-freebsd*
5000 * Multi-arched targets.
5002 HP/PA HPUX11 hppa*-*-hpux*
5003 Renesas M32R/D w/simulator m32r-*-elf*
5005 * OBSOLETE configurations and files
5007 Configurations that have been declared obsolete in this release have
5008 been commented out. Unless there is activity to revive these
5009 configurations, the next release of GDB will have their sources
5010 permanently REMOVED.
5012 Z8000 simulator z8k-zilog-none or z8ksim
5013 Matsushita MN10200 w/simulator mn10200-*-*
5014 H8/500 simulator h8500-hitachi-hms or h8500hms
5015 HP/PA running BSD hppa*-*-bsd*
5016 HP/PA running OSF/1 hppa*-*-osf*
5017 HP/PA Pro target hppa*-*-pro*
5018 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5019 Sequent family i[3456]86-sequent-sysv4*
5020 i[3456]86-sequent-sysv*
5021 i[3456]86-sequent-bsd*
5022 Tsqware Sparclet sparclet-*-*
5023 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5025 * REMOVED configurations and files
5028 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5029 IBM AIX PS/2 i[3456]86-*-aix
5030 i386 running Mach 3.0 i[3456]86-*-mach3*
5031 i386 running Mach i[3456]86-*-mach*
5032 i386 running OSF/1 i[3456]86-*osf1mk*
5033 HP/Apollo 68k Family m68*-apollo*-sysv*,
5035 m68*-hp-bsd*, m68*-hp-hpux*
5036 Argonaut Risc Chip (ARC) arc-*-*
5037 Mitsubishi D30V d30v-*-*
5038 Fujitsu FR30 fr30-*-elf*
5039 OS/9000 i[34]86-*-os9k
5040 I960 with MON960 i960-*-coff
5042 * MIPS $fp behavior changed
5044 The convenience variable $fp, for the MIPS, now consistently returns
5045 the address of the current frame's base. Previously, depending on the
5046 context, $fp could refer to either $sp or the current frame's base
5047 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5048 The GNU Source-Level Debugger''.
5050 *** Changes in GDB 5.3:
5052 * GNU/Linux shared library multi-threaded performance improved.
5054 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5055 `/proc', in preference to `ptrace' for memory reads. This may result
5056 in an improvement in the start-up time of multi-threaded, shared
5057 library applications when run under GDB. One GDB user writes: ``loads
5058 shared libs like mad''.
5060 * ``gdbserver'' now supports multi-threaded applications on some targets
5062 Support for debugging multi-threaded applications which use
5063 the GNU/Linux LinuxThreads package has been added for
5064 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5065 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5067 * GDB now supports C/C++ preprocessor macros.
5069 GDB now expands preprocessor macro invocations in C/C++ expressions,
5070 and provides various commands for showing macro definitions and how
5073 The new command `macro expand EXPRESSION' expands any macro
5074 invocations in expression, and shows the result.
5076 The new command `show macro MACRO-NAME' shows the definition of the
5077 macro named MACRO-NAME, and where it was defined.
5079 Most compilers don't include information about macros in the debugging
5080 information by default. In GCC 3.1, for example, you need to compile
5081 your program with the options `-gdwarf-2 -g3'. If the macro
5082 information is present in the executable, GDB will read it.
5084 * Multi-arched targets.
5086 DEC Alpha (partial) alpha*-*-*
5087 DEC VAX (partial) vax-*-*
5089 National Semiconductor NS32000 (partial) ns32k-*-*
5090 Motorola 68000 (partial) m68k-*-*
5091 Motorola MCORE mcore-*-*
5095 Fujitsu FRV architecture added by Red Hat frv*-*-*
5098 * New native configurations
5100 Alpha NetBSD alpha*-*-netbsd*
5101 SH NetBSD sh*-*-netbsdelf*
5102 MIPS NetBSD mips*-*-netbsd*
5103 UltraSPARC NetBSD sparc64-*-netbsd*
5105 * OBSOLETE configurations and files
5107 Configurations that have been declared obsolete in this release have
5108 been commented out. Unless there is activity to revive these
5109 configurations, the next release of GDB will have their sources
5110 permanently REMOVED.
5112 Mitsubishi D30V d30v-*-*
5113 OS/9000 i[34]86-*-os9k
5114 IBM AIX PS/2 i[3456]86-*-aix
5115 Fujitsu FR30 fr30-*-elf*
5116 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5117 Argonaut Risc Chip (ARC) arc-*-*
5118 i386 running Mach 3.0 i[3456]86-*-mach3*
5119 i386 running Mach i[3456]86-*-mach*
5120 i386 running OSF/1 i[3456]86-*osf1mk*
5121 HP/Apollo 68k Family m68*-apollo*-sysv*,
5123 m68*-hp-bsd*, m68*-hp-hpux*
5124 I960 with MON960 i960-*-coff
5126 * OBSOLETE languages
5128 CHILL, a Pascal like language used by telecommunications companies.
5130 * REMOVED configurations and files
5132 AMD 29k family via UDI a29k-amd-udi, udi29k
5133 A29K VxWorks a29k-*-vxworks
5134 AMD 29000 embedded, using EBMON a29k-none-none
5135 AMD 29000 embedded with COFF a29k-none-coff
5136 AMD 29000 embedded with a.out a29k-none-aout
5138 testsuite/gdb.hp/gdb.threads-hp/ directory
5140 * New command "set max-user-call-depth <nnn>"
5142 This command allows the user to limit the call depth of user-defined
5143 commands. The default is 1024.
5145 * Changes in FreeBSD/i386 native debugging.
5147 Support for the "generate-core-file" has been added.
5149 * New commands "dump", "append", and "restore".
5151 These commands allow data to be copied from target memory
5152 to a bfd-format or binary file (dump and append), and back
5153 from a file into memory (restore).
5155 * Improved "next/step" support on multi-processor Alpha Tru64.
5157 The previous single-step mechanism could cause unpredictable problems,
5158 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5159 of a software single-step mechanism prevents this.
5161 *** Changes in GDB 5.2.1:
5169 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5170 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5171 Fix, by Joel Brobecker imported from mainline.
5173 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5174 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5175 Fix, by Fred Fish, imported from mainline.
5177 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5178 Surprisingly enough, it works now.
5179 By Michal Ludvig, imported from mainline.
5181 i386 hardware watchpoint support:
5182 avoid misses on second run for some targets.
5183 By Pierre Muller, imported from mainline.
5185 *** Changes in GDB 5.2:
5187 * New command "set trust-readonly-sections on[off]".
5189 This command is a hint that tells gdb that read-only sections
5190 really are read-only (ie. that their contents will not change).
5191 In this mode, gdb will go to the object file rather than the
5192 target to read memory from read-only sections (such as ".text").
5193 This can be a significant performance improvement on some
5194 (notably embedded) targets.
5196 * New command "generate-core-file" (or "gcore").
5198 This new gdb command allows the user to drop a core file of the child
5199 process state at any time. So far it's been implemented only for
5200 GNU/Linux and Solaris, but should be relatively easily ported to other
5201 hosts. Argument is core file name (defaults to core.<pid>).
5203 * New command line option
5205 GDB now accepts --pid or -p followed by a process id.
5207 * Change in command line behavior -- corefiles vs. process ids.
5209 There is a subtle behavior in the way in which GDB handles
5210 command line arguments. The first non-flag argument is always
5211 a program to debug, but the second non-flag argument may either
5212 be a corefile or a process id. Previously, GDB would attempt to
5213 open the second argument as a corefile, and if that failed, would
5214 issue a superfluous error message and then attempt to attach it as
5215 a process. Now, if the second argument begins with a non-digit,
5216 it will be treated as a corefile. If it begins with a digit,
5217 GDB will attempt to attach it as a process, and if no such process
5218 is found, will then attempt to open it as a corefile.
5220 * Changes in ARM configurations.
5222 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5223 configuration is fully multi-arch.
5225 * New native configurations
5227 ARM NetBSD arm*-*-netbsd*
5228 x86 OpenBSD i[3456]86-*-openbsd*
5229 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5230 Sparc64 running FreeBSD sparc64-*-freebsd*
5234 Sanyo XStormy16 xstormy16-elf
5236 * OBSOLETE configurations and files
5238 Configurations that have been declared obsolete in this release have
5239 been commented out. Unless there is activity to revive these
5240 configurations, the next release of GDB will have their sources
5241 permanently REMOVED.
5243 AMD 29k family via UDI a29k-amd-udi, udi29k
5244 A29K VxWorks a29k-*-vxworks
5245 AMD 29000 embedded, using EBMON a29k-none-none
5246 AMD 29000 embedded with COFF a29k-none-coff
5247 AMD 29000 embedded with a.out a29k-none-aout
5249 testsuite/gdb.hp/gdb.threads-hp/ directory
5251 * REMOVED configurations and files
5253 TI TMS320C80 tic80-*-*
5255 PowerPC Solaris powerpcle-*-solaris*
5256 PowerPC Windows NT powerpcle-*-cygwin32
5257 PowerPC Netware powerpc-*-netware*
5258 Harris/CXUX m88k m88*-harris-cxux*
5259 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5260 ns32k-utek-sysv* ns32k-utek-*
5261 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5262 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5263 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5264 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5265 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5267 * Changes to command line processing
5269 The new `--args' feature can be used to specify command-line arguments
5270 for the inferior from gdb's command line.
5272 * Changes to key bindings
5274 There is a new `operate-and-get-next' function bound to `C-o'.
5276 *** Changes in GDB 5.1.1
5278 Fix compile problem on DJGPP.
5280 Fix a problem with floating-point registers on the i386 being
5283 Fix to stop GDB crashing on .debug_str debug info.
5285 Numerous documentation fixes.
5287 Numerous testsuite fixes.
5289 *** Changes in GDB 5.1:
5291 * New native configurations
5293 Alpha FreeBSD alpha*-*-freebsd*
5294 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5295 MIPS GNU/Linux mips*-*-linux*
5296 MIPS SGI Irix 6.x mips*-sgi-irix6*
5297 ia64 AIX ia64-*-aix*
5298 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5302 Motorola 68HC11 and 68HC12 m68hc11-elf
5304 UltraSparc running GNU/Linux sparc64-*-linux*
5306 * OBSOLETE configurations and files
5308 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5309 Harris/CXUX m88k m88*-harris-cxux*
5310 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5311 ns32k-utek-sysv* ns32k-utek-*
5312 TI TMS320C80 tic80-*-*
5314 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5315 PowerPC Solaris powerpcle-*-solaris*
5316 PowerPC Windows NT powerpcle-*-cygwin32
5317 PowerPC Netware powerpc-*-netware*
5318 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5319 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5320 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5321 Apple Macintosh (MPW) host N/A
5323 stuff.c (Program to stuff files into a specially prepared space in kdb)
5324 kdb-start.c (Main loop for the standalone kernel debugger)
5326 Configurations that have been declared obsolete in this release have
5327 been commented out. Unless there is activity to revive these
5328 configurations, the next release of GDB will have their sources
5329 permanently REMOVED.
5331 * REMOVED configurations and files
5333 Altos 3068 m68*-altos-*
5334 Convex c1-*-*, c2-*-*
5336 ARM RISCix arm-*-* (as host)
5340 * GDB has been converted to ISO C.
5342 GDB's source code has been converted to ISO C. In particular, the
5343 sources are fully protoized, and rely on standard headers being
5348 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5350 * The MI enabled by default.
5352 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5353 revised and enabled by default. Packages which use GDB as a debugging
5354 engine behind a UI or another front end are encouraged to switch to
5355 using the GDB/MI interface, instead of the old annotations interface
5356 which is now deprecated.
5358 * Support for debugging Pascal programs.
5360 GDB now includes support for debugging Pascal programs. The following
5361 main features are supported:
5363 - Pascal-specific data types such as sets;
5365 - automatic recognition of Pascal sources based on file-name
5368 - Pascal-style display of data types, variables, and functions;
5370 - a Pascal expression parser.
5372 However, some important features are not yet supported.
5374 - Pascal string operations are not supported at all;
5376 - there are some problems with boolean types;
5378 - Pascal type hexadecimal constants are not supported
5379 because they conflict with the internal variables format;
5381 - support for Pascal objects and classes is not full yet;
5383 - unlike Pascal, GDB is case-sensitive for symbol names.
5385 * Changes in completion.
5387 Commands such as `shell', `run' and `set args', which pass arguments
5388 to inferior programs, now complete on file names, similar to what
5389 users expect at the shell prompt.
5391 Commands which accept locations, such as `disassemble', `print',
5392 `breakpoint', `until', etc. now complete on filenames as well as
5393 program symbols. Thus, if you type "break foob TAB", and the source
5394 files linked into the programs include `foobar.c', that file name will
5395 be one of the candidates for completion. However, file names are not
5396 considered for completion after you typed a colon that delimits a file
5397 name from a name of a function in that file, as in "break foo.c:bar".
5399 `set demangle-style' completes on available demangling styles.
5401 * New platform-independent commands:
5403 It is now possible to define a post-hook for a command as well as a
5404 hook that runs before the command. For more details, see the
5405 documentation of `hookpost' in the GDB manual.
5407 * Changes in GNU/Linux native debugging.
5409 Support for debugging multi-threaded programs has been completely
5410 revised for all platforms except m68k and sparc. You can now debug as
5411 many threads as your system allows you to have.
5413 Attach/detach is supported for multi-threaded programs.
5415 Support for SSE registers was added for x86. This doesn't work for
5416 multi-threaded programs though.
5418 * Changes in MIPS configurations.
5420 Multi-arch support is enabled for all MIPS configurations.
5422 GDB can now be built as native debugger on SGI Irix 6.x systems for
5423 debugging n32 executables. (Debugging 64-bit executables is not yet
5426 * Unified support for hardware watchpoints in all x86 configurations.
5428 Most (if not all) native x86 configurations support hardware-assisted
5429 breakpoints and watchpoints in a unified manner. This support
5430 implements debug register sharing between watchpoints, which allows to
5431 put a virtually infinite number of watchpoints on the same address,
5432 and also supports watching regions up to 16 bytes with several debug
5435 The new maintenance command `maintenance show-debug-regs' toggles
5436 debugging print-outs in functions that insert, remove, and test
5437 watchpoints and hardware breakpoints.
5439 * Changes in the DJGPP native configuration.
5441 New command ``info dos sysinfo'' displays assorted information about
5442 the CPU, OS, memory, and DPMI server.
5444 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5445 display information about segment descriptors stored in GDT, LDT, and
5448 New commands ``info dos pde'' and ``info dos pte'' display entries
5449 from Page Directory and Page Tables (for now works with CWSDPMI only).
5450 New command ``info dos address-pte'' displays the Page Table entry for
5451 a given linear address.
5453 GDB can now pass command lines longer than 126 characters to the
5454 program being debugged (requires an update to the libdbg.a library
5455 which is part of the DJGPP development kit).
5457 DWARF2 debug info is now supported.
5459 It is now possible to `step' and `next' through calls to `longjmp'.
5461 * Changes in documentation.
5463 All GDB documentation was converted to GFDL, the GNU Free
5464 Documentation License.
5466 Tracepoints-related commands are now fully documented in the GDB
5469 TUI, the Text-mode User Interface, is now documented in the manual.
5471 Tracepoints-related commands are now fully documented in the GDB
5474 The "GDB Internals" manual now has an index. It also includes
5475 documentation of `ui_out' functions, GDB coding standards, x86
5476 hardware watchpoints, and memory region attributes.
5478 * GDB's version number moved to ``version.in''
5480 The Makefile variable VERSION has been replaced by the file
5481 ``version.in''. People creating GDB distributions should update the
5482 contents of this file.
5486 GUD support is now a standard part of the EMACS distribution.
5488 *** Changes in GDB 5.0:
5490 * Improved support for debugging FP programs on x86 targets
5492 Unified and much-improved support for debugging floating-point
5493 programs on all x86 targets. In particular, ``info float'' now
5494 displays the FP registers in the same format on all x86 targets, with
5495 greater level of detail.
5497 * Improvements and bugfixes in hardware-assisted watchpoints
5499 It is now possible to watch array elements, struct members, and
5500 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5501 on x86 targets no longer erroneously trigger when the address is
5504 * Improvements in the native DJGPP version of GDB
5506 The distribution now includes all the scripts and auxiliary files
5507 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5508 machines ``out of the box''.
5510 The DJGPP version can now debug programs that use signals. It is
5511 possible to catch signals that happened in the debuggee, deliver
5512 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5513 would kill the program being debugged.) Programs that hook hardware
5514 interrupts (keyboard, timer, etc.) can also be debugged.
5516 It is now possible to debug DJGPP programs that redirect their
5517 standard handles or switch them to raw (as opposed to cooked) mode, or
5518 even close them. The command ``run < foo > bar'' works as expected,
5519 and ``info terminal'' reports useful information about the debuggee's
5520 terminal, including raw/cooked mode, redirection, etc.
5522 The DJGPP version now uses termios functions for console I/O, which
5523 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5526 DOS-style file names with drive letters are now fully supported by
5529 It is now possible to debug DJGPP programs that switch their working
5530 directory. It is also possible to rerun the debuggee any number of
5531 times without restarting GDB; thus, you can use the same setup,
5532 breakpoints, etc. for many debugging sessions.
5534 * New native configurations
5536 ARM GNU/Linux arm*-*-linux*
5537 PowerPC GNU/Linux powerpc-*-linux*
5541 Motorola MCore mcore-*-*
5542 x86 VxWorks i[3456]86-*-vxworks*
5543 PowerPC VxWorks powerpc-*-vxworks*
5544 TI TMS320C80 tic80-*-*
5546 * OBSOLETE configurations
5548 Altos 3068 m68*-altos-*
5549 Convex c1-*-*, c2-*-*
5551 ARM RISCix arm-*-* (as host)
5554 Configurations that have been declared obsolete will be commented out,
5555 but the code will be left in place. If there is no activity to revive
5556 these configurations before the next release of GDB, the sources will
5557 be permanently REMOVED.
5559 * Gould support removed
5561 Support for the Gould PowerNode and NP1 has been removed.
5563 * New features for SVR4
5565 On SVR4 native platforms (such as Solaris), if you attach to a process
5566 without first loading a symbol file, GDB will now attempt to locate and
5567 load symbols from the running process's executable file.
5569 * Many C++ enhancements
5571 C++ support has been greatly improved. Overload resolution now works properly
5572 in almost all cases. RTTI support is on the way.
5574 * Remote targets can connect to a sub-program
5576 A popen(3) style serial-device has been added. This device starts a
5577 sub-process (such as a stand-alone simulator) and then communicates
5578 with that. The sub-program to run is specified using the syntax
5579 ``|<program> <args>'' vis:
5581 (gdb) set remotedebug 1
5582 (gdb) target extended-remote |mn10300-elf-sim program-args
5584 * MIPS 64 remote protocol
5586 A long standing bug in the mips64 remote protocol where by GDB
5587 expected certain 32 bit registers (ex SR) to be transfered as 32
5588 instead of 64 bits has been fixed.
5590 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5591 added to provide backward compatibility with older versions of GDB.
5593 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5595 The command ``set remotebinarydownload'' command has been replaced by
5596 ``set remote X-packet''. Other commands in ``set remote'' family
5597 include ``set remote P-packet''.
5599 * Breakpoint commands accept ranges.
5601 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5602 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5603 ``tracepoint passcount'' also accepts a range of tracepoints.
5605 * ``apropos'' command added.
5607 The ``apropos'' command searches through command names and
5608 documentation strings, printing out matches, making it much easier to
5609 try to find a command that does what you are looking for.
5613 A new machine oriented interface (MI) has been added to GDB. This
5614 interface is designed for debug environments running GDB as a separate
5615 process. This is part of the long term libGDB project. See the
5616 "GDB/MI" chapter of the GDB manual for further information. It can be
5617 enabled by configuring with:
5619 .../configure --enable-gdbmi
5621 *** Changes in GDB-4.18:
5623 * New native configurations
5625 HP-UX 10.20 hppa*-*-hpux10.20
5626 HP-UX 11.x hppa*-*-hpux11.0*
5627 M68K GNU/Linux m68*-*-linux*
5631 Fujitsu FR30 fr30-*-elf*
5632 Intel StrongARM strongarm-*-*
5633 Mitsubishi D30V d30v-*-*
5635 * OBSOLETE configurations
5637 Gould PowerNode, NP1 np1-*-*, pn-*-*
5639 Configurations that have been declared obsolete will be commented out,
5640 but the code will be left in place. If there is no activity to revive
5641 these configurations before the next release of GDB, the sources will
5642 be permanently REMOVED.
5646 As a compatibility experiment, GDB's source files buildsym.h and
5647 buildsym.c have been converted to pure standard C, no longer
5648 containing any K&R compatibility code. We believe that all systems in
5649 use today either come with a standard C compiler, or have a GCC port
5650 available. If this is not true, please report the affected
5651 configuration to bug-gdb@gnu.org immediately. See the README file for
5652 information about getting a standard C compiler if you don't have one
5657 GDB now uses readline 2.2.
5659 * set extension-language
5661 You can now control the mapping between filename extensions and source
5662 languages by using the `set extension-language' command. For instance,
5663 you can ask GDB to treat .c files as C++ by saying
5664 set extension-language .c c++
5665 The command `info extensions' lists all of the recognized extensions
5666 and their associated languages.
5668 * Setting processor type for PowerPC and RS/6000
5670 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5671 you can use the `set processor' command to specify what variant of the
5672 PowerPC family you are debugging. The command
5676 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5677 following PowerPC and RS6000 variants:
5679 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5680 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5682 403GC IBM PowerPC 403GC
5683 505 Motorola PowerPC 505
5684 860 Motorola PowerPC 860 or 850
5685 601 Motorola PowerPC 601
5686 602 Motorola PowerPC 602
5687 603 Motorola/IBM PowerPC 603 or 603e
5688 604 Motorola PowerPC 604 or 604e
5689 750 Motorola/IBM PowerPC 750 or 750
5691 At the moment, this command just tells GDB what to name the
5692 special-purpose processor registers. Since almost all the affected
5693 registers are inaccessible to user-level programs, this command is
5694 only useful for remote debugging in its present form.
5698 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5699 more extensive support for HP-UX. Added features include shared
5700 library support, kernel threads and hardware watchpoints for 11.00,
5701 support for HP's ANSI C and C++ compilers, and a compatibility mode
5702 for xdb and dbx commands.
5706 HP's donation includes the new concept of catchpoints, which is a
5707 generalization of the old catch command. On HP-UX, it is now possible
5708 to catch exec, fork, and vfork, as well as library loading.
5710 This means that the existing catch command has changed; its first
5711 argument now specifies the type of catch to be set up. See the
5712 output of "help catch" for a list of catchpoint types.
5714 * Debugging across forks
5716 On HP-UX, you can choose which process to debug when a fork() happens
5721 HP has donated a curses-based terminal user interface (TUI). To get
5722 it, build with --enable-tui. Although this can be enabled for any
5723 configuration, at present it only works for native HP debugging.
5725 * GDB remote protocol additions
5727 A new protocol packet 'X' that writes binary data is now available.
5728 Default behavior is to try 'X', then drop back to 'M' if the stub
5729 fails to respond. The settable variable `remotebinarydownload'
5730 allows explicit control over the use of 'X'.
5732 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5733 full 64-bit address. The command
5735 set remoteaddresssize 32
5737 can be used to revert to the old behaviour. For existing remote stubs
5738 the change should not be noticed, as the additional address information
5741 In order to assist in debugging stubs, you may use the maintenance
5742 command `packet' to send any text string to the stub. For instance,
5744 maint packet heythere
5746 sends the packet "$heythere#<checksum>". Note that it is very easy to
5747 disrupt a debugging session by sending the wrong packet at the wrong
5750 The compare-sections command allows you to compare section data on the
5751 target to what is in the executable file without uploading or
5752 downloading, by comparing CRC checksums.
5754 * Tracing can collect general expressions
5756 You may now collect general expressions at tracepoints. This requires
5757 further additions to the target-side stub; see tracepoint.c and
5758 doc/agentexpr.texi for further details.
5760 * mask-address variable for Mips
5762 For Mips targets, you may control the zeroing of the upper 32 bits of
5763 a 64-bit address by entering `set mask-address on'. This is mainly
5764 of interest to users of embedded R4xxx and R5xxx processors.
5766 * Higher serial baud rates
5768 GDB's serial code now allows you to specify baud rates 57600, 115200,
5769 230400, and 460800 baud. (Note that your host system may not be able
5770 to achieve all of these rates.)
5774 The i960 configuration now includes an initial implementation of a
5775 builtin simulator, contributed by Jim Wilson.
5778 *** Changes in GDB-4.17:
5780 * New native configurations
5782 Alpha GNU/Linux alpha*-*-linux*
5783 Unixware 2.x i[3456]86-unixware2*
5784 Irix 6.x mips*-sgi-irix6*
5785 PowerPC GNU/Linux powerpc-*-linux*
5786 PowerPC Solaris powerpcle-*-solaris*
5787 Sparc GNU/Linux sparc-*-linux*
5788 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5792 Argonaut Risc Chip (ARC) arc-*-*
5793 Hitachi H8/300S h8300*-*-*
5794 Matsushita MN10200 w/simulator mn10200-*-*
5795 Matsushita MN10300 w/simulator mn10300-*-*
5796 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5797 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5798 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5799 Mitsubishi D10V w/simulator d10v-*-*
5800 Mitsubishi M32R/D w/simulator m32r-*-elf*
5801 Tsqware Sparclet sparclet-*-*
5802 NEC V850 w/simulator v850-*-*
5804 * New debugging protocols
5806 ARM with RDI protocol arm*-*-*
5807 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5808 DDB and LSI variants of PMON protocol mips*-*-*
5809 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5810 PowerPC with SDS protocol powerpc{,le}-*-eabi
5811 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5815 All configurations can now understand and use the DWARF 2 debugging
5816 format. The choice is automatic, if the symbol file contains DWARF 2
5821 GDB now includes basic Java language support. This support is
5822 only useful with Java compilers that produce native machine code.
5824 * solib-absolute-prefix and solib-search-path
5826 For SunOS and SVR4 shared libraries, you may now set the prefix for
5827 loading absolute shared library symbol files, and the search path for
5828 locating non-absolute shared library symbol files.
5830 * Live range splitting
5832 GDB can now effectively debug code for which GCC has performed live
5833 range splitting as part of its optimization. See gdb/doc/LRS for
5834 more details on the expected format of the stabs information.
5838 GDB's support for the GNU Hurd, including thread debugging, has been
5839 updated to work with current versions of the Hurd.
5843 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5844 instruction set. ARM GDB automatically detects when Thumb
5845 instructions are in use, and adjusts disassembly and backtracing
5850 GDB's MIPS target configurations now handle the MIP16 16-bit
5855 GDB now includes support for overlays; if an executable has been
5856 linked such that multiple sections are based at the same address, GDB
5857 will decide which section to use for symbolic info. You can choose to
5858 control the decision manually, using overlay commands, or implement
5859 additional target-side support and use "overlay load-target" to bring
5860 in the overlay mapping. Do "help overlay" for more detail.
5864 The command "info symbol <address>" displays information about
5865 the symbol at the specified address.
5869 The standard remote protocol now includes an extension that allows
5870 asynchronous collection and display of trace data. This requires
5871 extensive support in the target-side debugging stub. Tracing mode
5872 includes a new interaction mode in GDB and new commands: see the
5873 file tracepoint.c for more details.
5877 Configurations for embedded MIPS now include a simulator contributed
5878 by Cygnus Solutions. The simulator supports the instruction sets
5879 of most MIPS variants.
5883 Sparc configurations may now include the ERC32 simulator contributed
5884 by the European Space Agency. The simulator is not built into
5885 Sparc targets by default; configure with --enable-sim to include it.
5889 For target configurations that may include multiple variants of a
5890 basic architecture (such as MIPS and SH), you may now set the
5891 architecture explicitly. "set arch" sets, "info arch" lists
5892 the possible architectures.
5894 *** Changes in GDB-4.16:
5896 * New native configurations
5898 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5899 M68K NetBSD m68k-*-netbsd*
5900 PowerPC AIX 4.x powerpc-*-aix*
5901 PowerPC MacOS powerpc-*-macos*
5902 PowerPC Windows NT powerpcle-*-cygwin32
5903 RS/6000 AIX 4.x rs6000-*-aix4*
5907 ARM with RDP protocol arm-*-*
5908 I960 with MON960 i960-*-coff
5909 MIPS VxWorks mips*-*-vxworks*
5910 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5911 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5913 Matra Sparclet sparclet-*-*
5917 The powerpc-eabi configuration now includes the PSIM simulator,
5918 contributed by Andrew Cagney, with assistance from Mike Meissner.
5919 PSIM is a very elaborate model of the PowerPC, including not only
5920 basic instruction set execution, but also details of execution unit
5921 performance and I/O hardware. See sim/ppc/README for more details.
5925 GDB now works with Solaris 2.5.
5927 * Windows 95/NT native
5929 GDB will now work as a native debugger on Windows 95 and Windows NT.
5930 To build it from source, you must use the "gnu-win32" environment,
5931 which uses a DLL to emulate enough of Unix to run the GNU tools.
5932 Further information, binaries, and sources are available at
5933 ftp.cygnus.com, under pub/gnu-win32.
5935 * dont-repeat command
5937 If a user-defined command includes the command `dont-repeat', then the
5938 command will not be repeated if the user just types return. This is
5939 useful if the command is time-consuming to run, so that accidental
5940 extra keystrokes don't run the same command many times.
5942 * Send break instead of ^C
5944 The standard remote protocol now includes an option to send a break
5945 rather than a ^C to the target in order to interrupt it. By default,
5946 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5948 * Remote protocol timeout
5950 The standard remote protocol includes a new variable `remotetimeout'
5951 that allows you to set the number of seconds before GDB gives up trying
5952 to read from the target. The default value is 2.
5954 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5956 By default GDB will automatically keep track of objects as they are
5957 loaded and unloaded by the dynamic linker. By using the command `set
5958 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5959 when shared library events occur, thus allowing you to set breakpoints
5960 in shared libraries which are explicitly loaded by the inferior.
5962 Note this feature does not work on hpux8. On hpux9 you must link
5963 /usr/lib/end.o into your program. This feature should work
5964 automatically on hpux10.
5966 * Irix 5.x hardware watchpoint support
5968 Irix 5 configurations now support the use of hardware watchpoints.
5970 * Mips protocol "SYN garbage limit"
5972 When debugging a Mips target using the `target mips' protocol, you
5973 may set the number of characters that GDB will ignore by setting
5974 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5975 every character. The default value is 1050.
5977 * Recording and replaying remote debug sessions
5979 If you set `remotelogfile' to the name of a file, gdb will write to it
5980 a recording of a remote debug session. This recording may then be
5981 replayed back to gdb using "gdbreplay". See gdbserver/README for
5982 details. This is useful when you have a problem with GDB while doing
5983 remote debugging; you can make a recording of the session and send it
5984 to someone else, who can then recreate the problem.
5986 * Speedups for remote debugging
5988 GDB includes speedups for downloading and stepping MIPS systems using
5989 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5990 and more efficient S-record downloading.
5992 * Memory use reductions and statistics collection
5994 GDB now uses less memory and reports statistics about memory usage.
5995 Try the `maint print statistics' command, for example.
5997 *** Changes in GDB-4.15:
5999 * Psymtabs for XCOFF
6001 The symbol reader for AIX GDB now uses partial symbol tables. This
6002 can greatly improve startup time, especially for large executables.
6004 * Remote targets use caching
6006 Remote targets now use a data cache to speed up communication with the
6007 remote side. The data cache could lead to incorrect results because
6008 it doesn't know about volatile variables, thus making it impossible to
6009 debug targets which use memory mapped I/O devices. `set remotecache
6010 off' turns the the data cache off.
6012 * Remote targets may have threads
6014 The standard remote protocol now includes support for multiple threads
6015 in the target system, using new protocol commands 'H' and 'T'. See
6016 gdb/remote.c for details.
6020 If GDB is configured with `--enable-netrom', then it will include
6021 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6022 acts as though it is a bank of ROM on the target board, but you can
6023 write into it over the network. GDB's support consists only of
6024 support for fast loading into the emulated ROM; to debug, you must use
6025 another protocol, such as standard remote protocol. The usual
6026 sequence is something like
6028 target nrom <netrom-hostname>
6030 target remote <netrom-hostname>:1235
6034 GDB now includes support for the Apple Macintosh, as a host only. It
6035 may be run as either an MPW tool or as a standalone application, and
6036 it can debug through the serial port. All the usual GDB commands are
6037 available, but to the target command, you must supply "serial" as the
6038 device type instead of "/dev/ttyXX". See mpw-README in the main
6039 directory for more information on how to build. The MPW configuration
6040 scripts */mpw-config.in support only a few targets, and only the
6041 mips-idt-ecoff target has been tested.
6045 GDB configuration now uses autoconf. This is not user-visible,
6046 but does simplify configuration and building.
6050 GDB now supports hpux10.
6052 *** Changes in GDB-4.14:
6054 * New native configurations
6056 x86 FreeBSD i[345]86-*-freebsd
6057 x86 NetBSD i[345]86-*-netbsd
6058 NS32k NetBSD ns32k-*-netbsd
6059 Sparc NetBSD sparc-*-netbsd
6063 A29K VxWorks a29k-*-vxworks
6064 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6065 CPU32 EST-300 emulator m68*-*-est*
6066 PowerPC ELF powerpc-*-elf
6069 * Alpha OSF/1 support for procfs
6071 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6072 possible to attach to running processes. As the mounting of the /proc
6073 filesystem is optional on the Alpha, GDB automatically determines
6074 the availability of /proc during startup. This can lead to problems
6075 if /proc is unmounted after GDB has been started.
6077 * Arguments to user-defined commands
6079 User commands may accept up to 10 arguments separated by whitespace.
6080 Arguments are accessed within the user command via $arg0..$arg9. A
6083 print $arg0 + $arg1 + $arg2
6085 To execute the command use:
6088 Defines the command "adder" which prints the sum of its three arguments.
6089 Note the arguments are text substitutions, so they may reference variables,
6090 use complex expressions, or even perform inferior function calls.
6092 * New `if' and `while' commands
6094 This makes it possible to write more sophisticated user-defined
6095 commands. Both commands take a single argument, which is the
6096 expression to evaluate, and must be followed by the commands to
6097 execute, one per line, if the expression is nonzero, the list being
6098 terminated by the word `end'. The `if' command list may include an
6099 `else' word, which causes the following commands to be executed only
6100 if the expression is zero.
6102 * Fortran source language mode
6104 GDB now includes partial support for Fortran 77. It will recognize
6105 Fortran programs and can evaluate a subset of Fortran expressions, but
6106 variables and functions may not be handled correctly. GDB will work
6107 with G77, but does not yet know much about symbols emitted by other
6110 * Better HPUX support
6112 Most debugging facilities now work on dynamic executables for HPPAs
6113 running hpux9 or later. You can attach to running dynamically linked
6114 processes, but by default the dynamic libraries will be read-only, so
6115 for instance you won't be able to put breakpoints in them. To change
6116 that behavior do the following before running the program:
6122 This will cause the libraries to be mapped private and read-write.
6123 To revert to the normal behavior, do this:
6129 You cannot set breakpoints or examine data in the library until after
6130 the library is loaded if the function/data symbols do not have
6133 GDB can now also read debug symbols produced by the HP C compiler on
6134 HPPAs (sorry, no C++, Fortran or 68k support).
6136 * Target byte order now dynamically selectable
6138 You can choose which byte order to use with a target system, via the
6139 commands "set endian big" and "set endian little", and you can see the
6140 current setting by using "show endian". You can also give the command
6141 "set endian auto", in which case GDB will use the byte order
6142 associated with the executable. Currently, only embedded MIPS
6143 configurations support dynamic selection of target byte order.
6145 * New DOS host serial code
6147 This version uses DPMI interrupts to handle buffered I/O, so you
6148 no longer need to run asynctsr when debugging boards connected to
6151 *** Changes in GDB-4.13:
6153 * New "complete" command
6155 This lists all the possible completions for the rest of the line, if it
6156 were to be given as a command itself. This is intended for use by emacs.
6158 * Trailing space optional in prompt
6160 "set prompt" no longer adds a space for you after the prompt you set. This
6161 allows you to set a prompt which ends in a space or one that does not.
6163 * Breakpoint hit counts
6165 "info break" now displays a count of the number of times the breakpoint
6166 has been hit. This is especially useful in conjunction with "ignore"; you
6167 can ignore a large number of breakpoint hits, look at the breakpoint info
6168 to see how many times the breakpoint was hit, then run again, ignoring one
6169 less than that number, and this will get you quickly to the last hit of
6172 * Ability to stop printing at NULL character
6174 "set print null-stop" will cause GDB to stop printing the characters of
6175 an array when the first NULL is encountered. This is useful when large
6176 arrays actually contain only short strings.
6178 * Shared library breakpoints
6180 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6181 breakpoints in shared libraries before the executable is run.
6183 * Hardware watchpoints
6185 There is a new hardware breakpoint for the watch command for sparclite
6186 targets. See gdb/sparclite/hw_breakpoint.note.
6188 Hardware watchpoints are also now supported under GNU/Linux.
6192 Annotations have been added. These are for use with graphical interfaces,
6193 and are still experimental. Currently only gdba.el uses these.
6195 * Improved Irix 5 support
6197 GDB now works properly with Irix 5.2.
6199 * Improved HPPA support
6201 GDB now works properly with the latest GCC and GAS.
6203 * New native configurations
6205 Sequent PTX4 i[34]86-sequent-ptx4
6206 HPPA running OSF/1 hppa*-*-osf*
6207 Atari TT running SVR4 m68*-*-sysv4*
6208 RS/6000 LynxOS rs6000-*-lynxos*
6212 OS/9000 i[34]86-*-os9k
6213 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6216 * Hitachi SH7000 and E7000-PC ICE support
6218 There is now support for communicating with the Hitachi E7000-PC ICE.
6219 This is available automatically when GDB is configured for the SH.
6223 As usual, a variety of small fixes and improvements, both generic
6224 and configuration-specific. See the ChangeLog for more detail.
6226 *** Changes in GDB-4.12:
6228 * Irix 5 is now supported
6232 GDB-4.12 on the HPPA has a number of changes which make it unable
6233 to debug the output from the currently released versions of GCC and
6234 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6235 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6236 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6239 *** Changes in GDB-4.11:
6241 * User visible changes:
6245 The "set remotedebug" option is now consistent between the mips remote
6246 target, remote targets using the gdb-specific protocol, UDI (AMD's
6247 debug protocol for the 29k) and the 88k bug monitor. It is now an
6248 integer specifying a debug level (normally 0 or 1, but 2 means more
6249 debugging info for the mips target).
6251 * DEC Alpha native support
6253 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6254 debug info, but GDB works fairly well with the DEC compiler and should
6255 work with a future GCC release. See the README file for a few
6256 Alpha-specific notes.
6258 * Preliminary thread implementation
6260 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6262 * LynxOS native and target support for 386
6264 This release has been hosted on LynxOS 2.2, and also can be configured
6265 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6268 * Improvements in C++ mangling/demangling.
6270 This release has much better g++ debugging, specifically in name
6271 mangling/demangling, virtual function calls, print virtual table,
6272 call methods, ...etc.
6274 *** Changes in GDB-4.10:
6276 * User visible changes:
6278 Remote debugging using the GDB-specific (`target remote') protocol now
6279 supports the `load' command. This is only useful if you have some
6280 other way of getting the stub to the target system, and you can put it
6281 somewhere in memory where it won't get clobbered by the download.
6283 Filename completion now works.
6285 When run under emacs mode, the "info line" command now causes the
6286 arrow to point to the line specified. Also, "info line" prints
6287 addresses in symbolic form (as well as hex).
6289 All vxworks based targets now support a user settable option, called
6290 vxworks-timeout. This option represents the number of seconds gdb
6291 should wait for responses to rpc's. You might want to use this if
6292 your vxworks target is, perhaps, a slow software simulator or happens
6293 to be on the far side of a thin network line.
6297 This release contains support for using a DEC alpha as a GDB host for
6298 cross debugging. Native alpha debugging is not supported yet.
6301 *** Changes in GDB-4.9:
6305 This is the first GDB release which is accompanied by a matching testsuite.
6306 The testsuite requires installation of dejagnu, which should be available
6307 via ftp from most sites that carry GNU software.
6311 'Cfront' style demangling has had its name changed to 'ARM' style, to
6312 emphasize that it was written from the specifications in the C++ Annotated
6313 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6314 disclaimers, it still generated too much confusion with users attempting to
6315 use gdb with AT&T cfront.
6319 GDB now uses a standard remote interface to a simulator library.
6320 So far, the library contains simulators for the Zilog Z8001/2, the
6321 Hitachi H8/300, H8/500 and Super-H.
6323 * New targets supported
6325 H8/300 simulator h8300-hitachi-hms or h8300hms
6326 H8/500 simulator h8500-hitachi-hms or h8500hms
6327 SH simulator sh-hitachi-hms or sh
6328 Z8000 simulator z8k-zilog-none or z8ksim
6329 IDT MIPS board over serial line mips-idt-ecoff
6331 Cross-debugging to GO32 targets is supported. It requires a custom
6332 version of the i386-stub.c module which is integrated with the
6333 GO32 memory extender.
6335 * New remote protocols
6337 MIPS remote debugging protocol.
6339 * New source languages supported
6341 This version includes preliminary support for Chill, a Pascal like language
6342 used by telecommunications companies. Chill support is also being integrated
6343 into the GNU compiler, but we don't know when it will be publically available.
6346 *** Changes in GDB-4.8:
6348 * HP Precision Architecture supported
6350 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6351 version of this support was available as a set of patches from the
6352 University of Utah. GDB does not support debugging of programs
6353 compiled with the HP compiler, because HP will not document their file
6354 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6355 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6357 Many problems in the preliminary version have been fixed.
6359 * Faster and better demangling
6361 We have improved template demangling and fixed numerous bugs in the GNU style
6362 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6363 character types (wchar_t) are now supported. Demangling of each symbol is now
6364 only done once, and is cached when the symbol table for a file is read in.
6365 This results in a small increase in memory usage for C programs, a moderate
6366 increase in memory usage for C++ programs, and a fantastic speedup in
6369 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6370 from the specifications in the Annotated Reference Manual, which AT&T's
6371 compiler does not actually implement.
6373 * G++ multiple inheritance compiler problem
6375 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6376 inheritance lattices was reworked to properly discover ambiguities. We
6377 recently found an example which causes this new algorithm to fail in a
6378 very subtle way, producing bad debug information for those classes.
6379 The file 'gcc.patch' (in this directory) can be applied to gcc to
6380 circumvent the problem. A future GCC release will contain a complete
6383 The previous G++ debug info problem (mentioned below for the gdb-4.7
6384 release) is fixed in gcc version 2.3.2.
6386 * Improved configure script
6388 The `configure' script will now attempt to guess your system type if
6389 you don't supply a host system type. The old scheme of supplying a
6390 host system triplet is preferable over using this. All the magic is
6391 done in the new `config.guess' script. Examine it for details.
6393 We have also brought our configure script much more in line with the FSF's
6394 version. It now supports the --with-xxx options. In particular,
6395 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6396 The resulting GDB will not be able to read arbitrary object file formats --
6397 only the format ``expected'' to be used on the configured target system.
6398 We hope to make this the default in a future release.
6400 * Documentation improvements
6402 There's new internal documentation on how to modify GDB, and how to
6403 produce clean changes to the code. We implore people to read it
6404 before submitting changes.
6406 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6407 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6408 `info' files are also provided. To build `info' files from scratch,
6409 you will need the latest `makeinfo' release, which will be available in
6410 a future texinfo-X.Y release.
6412 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6413 We're not sure exactly which versions have this problem, but it has
6414 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6415 or better. If that isn't possible, there is a patch in
6416 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6417 around this problem.
6421 GDB now supports array constants that can be used in expressions typed in by
6422 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6423 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6426 The new directory `gdb/sparclite' contains a program that demonstrates
6427 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6429 * New native hosts supported
6431 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6432 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6434 * New targets supported
6436 AMD 29k family via UDI a29k-amd-udi or udi29k
6438 * New file formats supported
6440 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6441 HPUX core files, and SCO 3.2v2 core files.
6445 Attaching to processes now works again; thanks for the many bug reports.
6447 We have also stomped on a bunch of core dumps caused by
6448 printf_filtered("%s") problems.
6450 We eliminated a copyright problem on the rpc and ptrace header files
6451 for VxWorks, which was discovered at the last minute during the 4.7
6452 release. You should now be able to build a VxWorks GDB.
6454 You can now interrupt gdb while an attached process is running. This
6455 will cause the attached process to stop, and give control back to GDB.
6457 We fixed problems caused by using too many file descriptors
6458 for reading symbols from object files and libraries. This was
6459 especially a problem for programs that used many (~100) shared
6462 The `step' command now only enters a subroutine if there is line number
6463 information for the subroutine. Otherwise it acts like the `next'
6464 command. Previously, `step' would enter subroutines if there was
6465 any debugging information about the routine. This avoids problems
6466 when using `cc -g1' on MIPS machines.
6468 * Internal improvements
6470 GDB's internal interfaces have been improved to make it easier to support
6471 debugging of multiple languages in the future.
6473 GDB now uses a common structure for symbol information internally.
6474 Minimal symbols (derived from linkage symbols in object files), partial
6475 symbols (from a quick scan of debug information), and full symbols
6476 contain a common subset of information, making it easier to write
6477 shared code that handles any of them.
6479 * New command line options
6481 We now accept --silent as an alias for --quiet.
6485 The memory-mapped-malloc library is now licensed under the GNU Library
6486 General Public License.
6488 *** Changes in GDB-4.7:
6490 * Host/native/target split
6492 GDB has had some major internal surgery to untangle the support for
6493 hosts and remote targets. Now, when you configure GDB for a remote
6494 target, it will no longer load in all of the support for debugging
6495 local programs on the host. When fully completed and tested, this will
6496 ensure that arbitrary host/target combinations are possible.
6498 The primary conceptual shift is to separate the non-portable code in
6499 GDB into three categories. Host specific code is required any time GDB
6500 is compiled on that host, regardless of the target. Target specific
6501 code relates to the peculiarities of the target, but can be compiled on
6502 any host. Native specific code is everything else: it can only be
6503 built when the host and target are the same system. Child process
6504 handling and core file support are two common `native' examples.
6506 GDB's use of /proc for controlling Unix child processes is now cleaner.
6507 It has been split out into a single module under the `target_ops' vector,
6508 plus two native-dependent functions for each system that uses /proc.
6510 * New hosts supported
6512 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6513 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6514 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6516 * New targets supported
6518 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6519 68030 and CPU32 m68030-*-*, m68332-*-*
6521 * New native hosts supported
6523 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6524 (386bsd is not well tested yet)
6525 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6527 * New file formats supported
6529 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6530 supports reading of `a.out.adobe' object files, which are an a.out
6531 format extended with minimal information about multiple sections.
6535 `show copying' is the same as the old `info copying'.
6536 `show warranty' is the same as `info warrantee'.
6537 These were renamed for consistency. The old commands continue to work.
6539 `info handle' is a new alias for `info signals'.
6541 You can now define pre-command hooks, which attach arbitrary command
6542 scripts to any command. The commands in the hook will be executed
6543 prior to the user's command. You can also create a hook which will be
6544 executed whenever the program stops. See gdb.texinfo.
6548 We now deal with Cfront style name mangling, and can even extract type
6549 info from mangled symbols. GDB can automatically figure out which
6550 symbol mangling style your C++ compiler uses.
6552 Calling of methods and virtual functions has been improved as well.
6556 The crash that occured when debugging Sun Ansi-C compiled binaries is
6557 fixed. This was due to mishandling of the extra N_SO stabs output
6560 We also finally got Ultrix 4.2 running in house, and fixed core file
6561 support, with help from a dozen people on the net.
6563 John M. Farrell discovered that the reason that single-stepping was so
6564 slow on all of the Mips based platforms (primarily SGI and DEC) was
6565 that we were trying to demangle and lookup a symbol used for internal
6566 purposes on every instruction that was being stepped through. Changing
6567 the name of that symbol so that it couldn't be mistaken for a C++
6568 mangled symbol sped things up a great deal.
6570 Rich Pixley sped up symbol lookups in general by getting much smarter
6571 about when C++ symbol mangling is necessary. This should make symbol
6572 completion (TAB on the command line) much faster. It's not as fast as
6573 we'd like, but it's significantly faster than gdb-4.6.
6577 A new user controllable variable 'call_scratch_address' can
6578 specify the location of a scratch area to be used when GDB
6579 calls a function in the target. This is necessary because the
6580 usual method of putting the scratch area on the stack does not work
6581 in systems that have separate instruction and data spaces.
6583 We integrated changes to support the 29k UDI (Universal Debugger
6584 Interface), but discovered at the last minute that we didn't have all
6585 of the appropriate copyright paperwork. We are working with AMD to
6586 resolve this, and hope to have it available soon.
6590 We have sped up the remote serial line protocol, especially for targets
6591 with lots of registers. It now supports a new `expedited status' ('T')
6592 message which can be used in place of the existing 'S' status message.
6593 This allows the remote stub to send only the registers that GDB
6594 needs to make a quick decision about single-stepping or conditional
6595 breakpoints, eliminating the need to fetch the entire register set for
6596 each instruction being stepped through.
6598 The GDB remote serial protocol now implements a write-through cache for
6599 registers, only re-reading the registers if the target has run.
6601 There is also a new remote serial stub for SPARC processors. You can
6602 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6603 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6604 processor with a serial port.
6608 Configure.in files have become much easier to read and modify. A new
6609 `table driven' format makes it more obvious what configurations are
6610 supported, and what files each one uses.
6614 There is a new opcodes library which will eventually contain all of the
6615 disassembly routines and opcode tables. At present, it only contains
6616 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6617 disassembler (binutils/objdump) to share these routines.
6619 The libiberty library is now copylefted under the GNU Library General
6620 Public License. This allows more liberal use, and was done so libg++
6621 can use it. This makes no difference to GDB, since the Library License
6622 grants all the rights from the General Public License.
6626 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6627 reference to the stabs symbol info used by the debugger. It is (as far
6628 as we know) the only published document on this fascinating topic. We
6629 encourage you to read it, compare it to the stabs information on your
6630 system, and send improvements on the document in general (to
6631 bug-gdb@prep.ai.mit.edu).
6633 And, of course, many bugs have been fixed.
6636 *** Changes in GDB-4.6:
6638 * Better support for C++ function names
6640 GDB now accepts as input the "demangled form" of C++ overloaded function
6641 names and member function names, and can do command completion on such names
6642 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6643 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6644 Make use of command completion, it is your friend.
6646 GDB also now accepts a variety of C++ mangled symbol formats. They are
6647 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6648 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6649 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6650 for the list of formats.
6652 * G++ symbol mangling problem
6654 Recent versions of gcc have a bug in how they emit debugging information for
6655 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6656 directory) can be applied to gcc to fix the problem. Alternatively, if you
6657 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6658 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6659 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6662 * New 'maintenance' command
6664 All of the commands related to hacking GDB internals have been moved out of
6665 the main command set, and now live behind the 'maintenance' command. This
6666 can also be abbreviated as 'mt'. The following changes were made:
6668 dump-me -> maintenance dump-me
6669 info all-breakpoints -> maintenance info breakpoints
6670 printmsyms -> maintenance print msyms
6671 printobjfiles -> maintenance print objfiles
6672 printpsyms -> maintenance print psymbols
6673 printsyms -> maintenance print symbols
6675 The following commands are new:
6677 maintenance demangle Call internal GDB demangler routine to
6678 demangle a C++ link name and prints the result.
6679 maintenance print type Print a type chain for a given symbol
6681 * Change to .gdbinit file processing
6683 We now read the $HOME/.gdbinit file before processing the argv arguments
6684 (e.g. reading symbol files or core files). This allows global parameters to
6685 be set, which will apply during the symbol reading. The ./.gdbinit is still
6686 read after argv processing.
6688 * New hosts supported
6690 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6692 GNU/Linux support i386-unknown-linux or linux
6694 We are also including code to support the HP/PA running BSD and HPUX. This
6695 is almost guaranteed not to work, as we didn't have time to test or build it
6696 for this release. We are including it so that the more adventurous (or
6697 masochistic) of you can play with it. We also had major problems with the
6698 fact that the compiler that we got from HP doesn't support the -g option.
6701 * New targets supported
6703 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6705 * More smarts about finding #include files
6707 GDB now remembers the compilation directory for all include files, and for
6708 all files from which C is generated (like yacc and lex sources). This
6709 greatly improves GDB's ability to find yacc/lex sources, and include files,
6710 especially if you are debugging your program from a directory different from
6711 the one that contains your sources.
6713 We also fixed a bug which caused difficulty with listing and setting
6714 breakpoints in include files which contain C code. (In the past, you had to
6715 try twice in order to list an include file that you hadn't looked at before.)
6717 * Interesting infernals change
6719 GDB now deals with arbitrary numbers of sections, where the symbols for each
6720 section must be relocated relative to that section's landing place in the
6721 target's address space. This work was needed to support ELF with embedded
6722 stabs used by Solaris-2.0.
6724 * Bug fixes (of course!)
6726 There have been loads of fixes for the following things:
6727 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6728 i960, stabs, DOS(GO32), procfs, etc...
6730 See the ChangeLog for details.
6732 *** Changes in GDB-4.5:
6734 * New machines supported (host and target)
6736 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6738 SGI Irix-4.x mips-sgi-irix4 or iris4
6740 * New malloc package
6742 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6743 Mmalloc is capable of handling mutiple heaps of memory. It is also
6744 capable of saving a heap to a file, and then mapping it back in later.
6745 This can be used to greatly speedup the startup of GDB by using a
6746 pre-parsed symbol table which lives in a mmalloc managed heap. For
6747 more details, please read mmalloc/mmalloc.texi.
6751 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6752 'help info proc' for details.
6754 * MIPS ecoff symbol table format
6756 The code that reads MIPS symbol table format is now supported on all hosts.
6757 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6760 * File name changes for MS-DOS
6762 Many files in the config directories have been renamed to make it easier to
6763 support GDB on MS-DOSe systems (which have very restrictive file name
6764 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6765 environment) is close to working but has some remaining problems. Note
6766 that debugging of DOS programs is not supported, due to limitations
6767 in the ``operating system'', but it can be used to host cross-debugging.
6769 * Cross byte order fixes
6771 Many fixes have been made to support cross debugging of Sparc and MIPS
6772 targets from hosts whose byte order differs.
6774 * New -mapped and -readnow options
6776 If memory-mapped files are available on your system through the 'mmap'
6777 system call, you can use the -mapped option on the `file' or
6778 `symbol-file' commands to cause GDB to write the symbols from your
6779 program into a reusable file. If the program you are debugging is
6780 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6781 Future GDB debugging sessions will notice the presence of this file,
6782 and will quickly map in symbol information from it, rather than reading
6783 the symbol table from the executable program. Using the '-mapped'
6784 option in a GDB `file' or `symbol-file' command has the same effect as
6785 starting GDB with the '-mapped' command-line option.
6787 You can cause GDB to read the entire symbol table immediately by using
6788 the '-readnow' option with any of the commands that load symbol table
6789 information (or on the GDB command line). This makes the command
6790 slower, but makes future operations faster.
6792 The -mapped and -readnow options are typically combined in order to
6793 build a `fred.syms' file that contains complete symbol information.
6794 A simple GDB invocation to do nothing but build a `.syms' file for future
6797 gdb -batch -nx -mapped -readnow programname
6799 The `.syms' file is specific to the host machine on which GDB is run.
6800 It holds an exact image of GDB's internal symbol table. It cannot be
6801 shared across multiple host platforms.
6803 * longjmp() handling
6805 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6806 siglongjmp() without losing control. This feature has not yet been ported to
6807 all systems. It currently works on many 386 platforms, all MIPS-based
6808 platforms (SGI, DECstation, etc), and Sun3/4.
6812 Preliminary work has been put in to support the new Solaris OS from Sun. At
6813 this time, it can control and debug processes, but it is not capable of
6818 As always, many many bug fixes. The major areas were with g++, and mipsread.
6819 People using the MIPS-based platforms should experience fewer mysterious
6820 crashes and trashed symbol tables.
6822 *** Changes in GDB-4.4:
6824 * New machines supported (host and target)
6826 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6828 BSD Reno on Vax vax-dec-bsd
6829 Ultrix on Vax vax-dec-ultrix
6831 * New machines supported (target)
6833 AMD 29000 embedded, using EBMON a29k-none-none
6837 GDB continues to improve its handling of C++. `References' work better.
6838 The demangler has also been improved, and now deals with symbols mangled as
6839 per the Annotated C++ Reference Guide.
6841 GDB also now handles `stabs' symbol information embedded in MIPS
6842 `ecoff' symbol tables. Since the ecoff format was not easily
6843 extensible to handle new languages such as C++, this appeared to be a
6844 good way to put C++ debugging info into MIPS binaries. This option
6845 will be supported in the GNU C compiler, version 2, when it is
6848 * New features for SVR4
6850 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6851 shared libraries. Debugging dynamically linked programs should present
6852 only minor differences from debugging statically linked programs.
6854 The `info proc' command will print out information about any process
6855 on an SVR4 system (including the one you are debugging). At the moment,
6856 it prints the address mappings of the process.
6858 If you bring up GDB on another SVR4 system, please send mail to
6859 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6861 * Better dynamic linking support in SunOS
6863 Reading symbols from shared libraries which contain debugging symbols
6864 now works properly. However, there remain issues such as automatic
6865 skipping of `transfer vector' code during function calls, which
6866 make it harder to debug code in a shared library, than to debug the
6867 same code linked statically.
6871 GDB is now using the latest `getopt' routines from the FSF. This
6872 version accepts the -- prefix for options with long names. GDB will
6873 continue to accept the old forms (-option and +option) as well.
6874 Various single letter abbreviations for options have been explicity
6875 added to the option table so that they won't get overshadowed in the
6876 future by other options that begin with the same letter.
6880 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6881 Many assorted bugs have been handled. Many more remain to be handled.
6882 See the various ChangeLog files (primarily in gdb and bfd) for details.
6885 *** Changes in GDB-4.3:
6887 * New machines supported (host and target)
6889 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6890 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6891 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6893 * Almost SCO Unix support
6895 We had hoped to support:
6896 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6897 (except for core file support), but we discovered very late in the release
6898 that it has problems with process groups that render gdb unusable. Sorry
6899 about that. I encourage people to fix it and post the fixes.
6901 * Preliminary ELF and DWARF support
6903 GDB can read ELF object files on System V Release 4, and can handle
6904 debugging records for C, in DWARF format, in ELF files. This support
6905 is preliminary. If you bring up GDB on another SVR4 system, please
6906 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6911 GDB now uses the latest `readline' library. One user-visible change
6912 is that two tabs will list possible command completions, which previously
6913 required typing M-? (meta-question mark, or ESC ?).
6917 The `stepi' bug that many of you noticed has been squashed.
6918 Many bugs in C++ have been handled. Many more remain to be handled.
6919 See the various ChangeLog files (primarily in gdb and bfd) for details.
6921 * State of the MIPS world (in case you wondered):
6923 GDB can understand the symbol tables emitted by the compilers
6924 supplied by most vendors of MIPS-based machines, including DEC. These
6925 symbol tables are in a format that essentially nobody else uses.
6927 Some versions of gcc come with an assembler post-processor called
6928 mips-tfile. This program is required if you want to do source-level
6929 debugging of gcc-compiled programs. I believe FSF does not ship
6930 mips-tfile with gcc version 1, but it will eventually come with gcc
6933 Debugging of g++ output remains a problem. g++ version 1.xx does not
6934 really support it at all. (If you're lucky, you should be able to get
6935 line numbers and stack traces to work, but no parameters or local
6936 variables.) With some work it should be possible to improve the
6939 When gcc version 2 is released, you will have somewhat better luck.
6940 However, even then you will get confusing results for inheritance and
6943 We will eventually provide full debugging of g++ output on
6944 DECstations. This will probably involve some kind of stabs-in-ecoff
6945 encapulation, but the details have not been worked out yet.
6948 *** Changes in GDB-4.2:
6950 * Improved configuration
6952 Only one copy of `configure' exists now, and it is not self-modifying.
6953 Porting BFD is simpler.
6957 The `step' and `next' commands now only stop at the first instruction
6958 of a source line. This prevents the multiple stops that used to occur
6959 in switch statements, for-loops, etc. `Step' continues to stop if a
6960 function that has debugging information is called within the line.
6964 Lots of small bugs fixed. More remain.
6966 * New host supported (not target)
6968 Intel 386 PC clone running Mach i386-none-mach
6971 *** Changes in GDB-4.1:
6973 * Multiple source language support
6975 GDB now has internal scaffolding to handle several source languages.
6976 It determines the type of each source file from its filename extension,
6977 and will switch expression parsing and number formatting to match the
6978 language of the function in the currently selected stack frame.
6979 You can also specifically set the language to be used, with
6980 `set language c' or `set language modula-2'.
6984 GDB now has preliminary support for the GNU Modula-2 compiler,
6985 currently under development at the State University of New York at
6986 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6987 continue through the fall of 1991 and into 1992.
6989 Other Modula-2 compilers are currently not supported, and attempting to
6990 debug programs compiled with them will likely result in an error as the
6991 symbol table is read. Feel free to work on it, though!
6993 There are hooks in GDB for strict type checking and range checking,
6994 in the `Modula-2 philosophy', but they do not currently work.
6998 GDB can now write to executable and core files (e.g. patch
6999 a variable's value). You must turn this switch on, specify
7000 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7001 by assigning a new value to a variable. Modifications take
7004 * Automatic SunOS shared library reading
7006 When you run your program, GDB automatically determines where its
7007 shared libraries (if any) have been loaded, and reads their symbols.
7008 The `share' command is no longer needed. This also works when
7009 examining core files.
7013 You can specify the number of lines that the `list' command shows.
7016 * New machines supported (host and target)
7018 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7019 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7020 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7022 * New hosts supported (not targets)
7024 IBM RT/PC: romp-ibm-aix or rtpc
7026 * New targets supported (not hosts)
7028 AMD 29000 embedded with COFF a29k-none-coff
7029 AMD 29000 embedded with a.out a29k-none-aout
7030 Ultracomputer remote kernel debug a29k-nyu-kern
7032 * New remote interfaces
7038 *** Changes in GDB-4.0:
7042 Wide output is wrapped at good places to make the output more readable.
7044 Gdb now supports cross-debugging from a host machine of one type to a
7045 target machine of another type. Communication with the target system
7046 is over serial lines. The ``target'' command handles connecting to the
7047 remote system; the ``load'' command will download a program into the
7048 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7049 also supports debugging of realtime processes running under VxWorks,
7050 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7051 stub on the target system.
7053 New CPUs supported include the AMD 29000 and Intel 960.
7055 GDB now reads object files and symbol tables via a ``binary file''
7056 library, which allows a single copy of GDB to debug programs of multiple
7057 object file types such as a.out and coff.
7059 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7060 refcard.dvi and refcard.ps are available to format it).
7063 * Control-Variable user interface simplified
7065 All variables that control the operation of the debugger can be set
7066 by the ``set'' command, and displayed by the ``show'' command.
7068 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7069 ``Show prompt'' produces the response:
7070 Gdb's prompt is new-gdb=>.
7072 What follows are the NEW set commands. The command ``help set'' will
7073 print a complete list of old and new set commands. ``help set FOO''
7074 will give a longer description of the variable FOO. ``show'' will show
7075 all of the variable descriptions and their current settings.
7077 confirm on/off: Enables warning questions for operations that are
7078 hard to recover from, e.g. rerunning the program while
7079 it is already running. Default is ON.
7081 editing on/off: Enables EMACS style command line editing
7082 of input. Previous lines can be recalled with
7083 control-P, the current line can be edited with control-B,
7084 you can search for commands with control-R, etc.
7087 history filename NAME: NAME is where the gdb command history
7088 will be stored. The default is .gdb_history,
7089 or the value of the environment variable
7092 history size N: The size, in commands, of the command history. The
7093 default is 256, or the value of the environment variable
7096 history save on/off: If this value is set to ON, the history file will
7097 be saved after exiting gdb. If set to OFF, the
7098 file will not be saved. The default is OFF.
7100 history expansion on/off: If this value is set to ON, then csh-like
7101 history expansion will be performed on
7102 command line input. The default is OFF.
7104 radix N: Sets the default radix for input and output. It can be set
7105 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7106 in the current radix, so "set radix 10" is always a no-op.
7108 height N: This integer value is the number of lines on a page. Default
7109 is 24, the current `stty rows'' setting, or the ``li#''
7110 setting from the termcap entry matching the environment
7113 width N: This integer value is the number of characters on a line.
7114 Default is 80, the current `stty cols'' setting, or the ``co#''
7115 setting from the termcap entry matching the environment
7118 Note: ``set screensize'' is obsolete. Use ``set height'' and
7119 ``set width'' instead.
7121 print address on/off: Print memory addresses in various command displays,
7122 such as stack traces and structure values. Gdb looks
7123 more ``symbolic'' if you turn this off; it looks more
7124 ``machine level'' with it on. Default is ON.
7126 print array on/off: Prettyprint arrays. New convenient format! Default
7129 print demangle on/off: Print C++ symbols in "source" form if on,
7132 print asm-demangle on/off: Same, for assembler level printouts
7135 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7138 * Support for Epoch Environment.
7140 The epoch environment is a version of Emacs v18 with windowing. One
7141 new command, ``inspect'', is identical to ``print'', except that if you
7142 are running in the epoch environment, the value is printed in its own
7146 * Support for Shared Libraries
7148 GDB can now debug programs and core files that use SunOS shared libraries.
7149 Symbols from a shared library cannot be referenced
7150 before the shared library has been linked with the program (this
7151 happens after you type ``run'' and before the function main() is entered).
7152 At any time after this linking (including when examining core files
7153 from dynamically linked programs), gdb reads the symbols from each
7154 shared library when you type the ``sharedlibrary'' command.
7155 It can be abbreviated ``share''.
7157 sharedlibrary REGEXP: Load shared object library symbols for files
7158 matching a unix regular expression. No argument
7159 indicates to load symbols for all shared libraries.
7161 info sharedlibrary: Status of loaded shared libraries.
7166 A watchpoint stops execution of a program whenever the value of an
7167 expression changes. Checking for this slows down execution
7168 tremendously whenever you are in the scope of the expression, but is
7169 quite useful for catching tough ``bit-spreader'' or pointer misuse
7170 problems. Some machines such as the 386 have hardware for doing this
7171 more quickly, and future versions of gdb will use this hardware.
7173 watch EXP: Set a watchpoint (breakpoint) for an expression.
7175 info watchpoints: Information about your watchpoints.
7177 delete N: Deletes watchpoint number N (same as breakpoints).
7178 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7179 enable N: Re-enables watchpoint number N (same as breakpoints).
7182 * C++ multiple inheritance
7184 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7187 * C++ exception handling
7189 Gdb now supports limited C++ exception handling. Besides the existing
7190 ability to breakpoint on an exception handler, gdb can breakpoint on
7191 the raising of an exception (before the stack is peeled back to the
7194 catch FOO: If there is a FOO exception handler in the dynamic scope,
7195 set a breakpoint to catch exceptions which may be raised there.
7196 Multiple exceptions (``catch foo bar baz'') may be caught.
7198 info catch: Lists all exceptions which may be caught in the
7199 current stack frame.
7202 * Minor command changes
7204 The command ``call func (arg, arg, ...)'' now acts like the print
7205 command, except it does not print or save a value if the function's result
7206 is void. This is similar to dbx usage.
7208 The ``up'' and ``down'' commands now always print the frame they end up
7209 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7210 frames without printing.
7212 * New directory command
7214 'dir' now adds directories to the FRONT of the source search path.
7215 The path starts off empty. Source files that contain debug information
7216 about the directory in which they were compiled can be found even
7217 with an empty path; Sun CC and GCC include this information. If GDB can't
7218 find your source file in the current directory, type "dir .".
7220 * Configuring GDB for compilation
7222 For normal use, type ``./configure host''. See README or gdb.texinfo
7225 GDB now handles cross debugging. If you are remotely debugging between
7226 two different machines, type ``./configure host -target=targ''.
7227 Host is the machine where GDB will run; targ is the machine
7228 where the program that you are debugging will run.
projects / external / binutils.git / blob