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.
41 * The RISC-V target now supports target descriptions.
46 GNU/Linux/OpenRISC or1k*-*-linux*
50 set debug compile-cplus-types
51 show debug compile-cplus-types
52 Control the display of debug output about type conversion in the
53 C++ compile feature. Commands have no effect while compiliong
58 Control whether debug output about files/functions skipping is
61 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
62 Apply a command to some frames.
63 FLAG arguments allow to control what output to produce and how to handle
64 errors raised when applying COMMAND to a frame.
67 Apply a command to all threads (ignoring errors and empty output).
68 Shortcut for 'thread apply all -s COMMAND'.
71 Apply a command to all frames (ignoring errors and empty output).
72 Shortcut for 'frame apply all -s COMMAND'.
75 Apply a command to all frames of all threads (ignoring errors and empty
77 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
79 maint set dwarf unwinders (on|off)
80 maint show dwarf unwinders
81 Control whether DWARF unwinders can be used.
84 Display a list of open files for a process.
88 target remote FILENAME
89 target extended-remote FILENAME
90 If FILENAME is a Unix domain socket, GDB will attempt to connect
91 to this socket instead of opening FILENAME as a character device.
93 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
94 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
95 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
96 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
97 These commands can now print only the searched entities
98 matching the provided regexp(s), giving a condition
99 on the entity names or entity types. The flag -q disables
100 printing headers or informations messages.
106 These commands now determine the syntax for the shown entities
107 according to the language chosen by `set language'. In particular,
108 `set language auto' means to automatically choose the language of
111 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
112 The 'thread apply' command accepts new FLAG arguments.
113 FLAG arguments allow to control what output to produce and how to handle
114 errors raised when applying COMMAND to a thread.
116 set tui tab-width NCHARS
117 show tui tab-width NCHARS
118 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
122 ** The '-data-disassemble' MI command now accepts an '-a' option to
123 disassemble the whole function surrounding the given program
124 counter value or function name. Support for this feature can be
125 verified by using the "-list-features" command, which should
126 contain "data-disassemble-a-option".
128 ** Command responses and notifications that include a frame now include
129 the frame's architecture in a new "arch" attribute.
131 * New native configurations
133 GNU/Linux/RISC-V riscv*-*-linux*
134 FreeBSD/riscv riscv*-*-freebsd*
138 GNU/Linux/RISC-V riscv*-*-linux*
140 CSKY GNU/LINUX csky*-*-linux
141 FreeBSD/riscv riscv*-*-freebsd*
145 ** The gdb.Inferior type has a new 'progspace' property, which is the program
146 space associated to that inferior.
148 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
149 of objfiles associated to that program space.
151 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
152 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
155 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
156 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
157 correct and did not work properly.
163 Enable or disable the undefined behavior sanitizer. This is
164 disabled by default, but passing --enable-ubsan=yes or
165 --enable-ubsan=auto to configure will enable it. Enabling this can
166 cause a performance penalty. The undefined behavior sanitizer was
167 first introduced in GCC 4.9.
169 *** Changes in GDB 8.2
171 * The 'set disassembler-options' command now supports specifying options
174 * The 'symbol-file' command now accepts an '-o' option to add a relative
175 offset to all sections.
177 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
178 a relative offset to all sections, but it allows to override the load
179 address of individual sections using '-s'.
181 * The 'add-symbol-file' command no longer requires the second argument
182 (address of the text section).
184 * The endianness used with the 'set endian auto' mode in the absence of
185 an executable selected for debugging is now the last endianness chosen
186 either by one of the 'set endian big' and 'set endian little' commands
187 or by inferring from the last executable used, rather than the startup
190 * The pager now allows a "c" response, meaning to disable the pager
191 for the rest of the current command.
193 * The commands 'info variables/functions/types' now show the source line
194 numbers of symbol definitions when available.
196 * 'info proc' now works on running processes on FreeBSD systems and core
197 files created on FreeBSD systems.
199 * C expressions can now use _Alignof, and C++ expressions can now use
202 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
203 the vector length while the process is running.
209 Control display of debugging info regarding the FreeBSD native target.
211 set|show varsize-limit
212 This new setting allows the user to control the maximum size of Ada
213 objects being printed when those objects have a variable type,
214 instead of that maximum size being hardcoded to 65536 bytes.
216 set|show record btrace cpu
217 Controls the processor to be used for enabling errata workarounds for
220 maint check libthread-db
221 Run integrity checks on the current inferior's thread debugging
224 maint set check-libthread-db (on|off)
225 maint show check-libthread-db
226 Control whether to run integrity checks on inferior specific thread
227 debugging libraries as they are loaded. The default is not to
232 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
234 ** The commands attached to a breakpoint can be set by assigning to
235 the breakpoint's "commands" field.
237 ** gdb.execute can now execute multi-line gdb commands.
239 ** The new functions gdb.convenience_variable and
240 gdb.set_convenience_variable can be used to get and set the value
241 of convenience variables.
243 ** A gdb.Parameter will no longer print the "set" help text on an
244 ordinary "set"; instead by default a "set" will be silent unless
245 the get_set_string method returns a non-empty string.
249 RiscV ELF riscv*-*-elf
251 * Removed targets and native configurations
253 m88k running OpenBSD m88*-*-openbsd*
254 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
255 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
256 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
258 * Aarch64/Linux hardware watchpoints improvements
260 Hardware watchpoints on unaligned addresses are now properly
261 supported when running Linux kernel 4.10 or higher: read and access
262 watchpoints are no longer spuriously missed, and all watchpoints
263 lengths between 1 and 8 bytes are supported. On older kernels,
264 watchpoints set on unaligned addresses are no longer missed, with
265 the tradeoff that there is a possibility of false hits being
270 --enable-codesign=CERT
271 This can be used to invoke "codesign -s CERT" after building gdb.
272 This option is useful on macOS, where code signing is required for
273 gdb to work properly.
275 --disable-gdbcli has been removed
276 This is now silently accepted, but does nothing.
278 *** Changes in GDB 8.1
280 * GDB now supports dynamically creating arbitrary register groups specified
281 in XML target descriptions. This allows for finer grain grouping of
282 registers on systems with a large amount of registers.
284 * The 'ptype' command now accepts a '/o' flag, which prints the
285 offsets and sizes of fields in a struct, like the pahole(1) tool.
287 * New "--readnever" command line option instructs GDB to not read each
288 symbol file's symbolic debug information. This makes startup faster
289 but at the expense of not being able to perform symbolic debugging.
290 This option is intended for use cases where symbolic debugging will
291 not be used, e.g., when you only need to dump the debuggee's core.
293 * GDB now uses the GNU MPFR library, if available, to emulate target
294 floating-point arithmetic during expression evaluation when the target
295 uses different floating-point formats than the host. At least version
296 3.1 of GNU MPFR is required.
298 * GDB now supports access to the guarded-storage-control registers and the
299 software-based guarded-storage broadcast control registers on IBM z14.
301 * On Unix systems, GDB now supports transmitting environment variables
302 that are to be set or unset to GDBserver. These variables will
303 affect the environment to be passed to the remote inferior.
305 To inform GDB of environment variables that are to be transmitted to
306 GDBserver, use the "set environment" command. Only user set
307 environment variables are sent to GDBserver.
309 To inform GDB of environment variables that are to be unset before
310 the remote inferior is started by the GDBserver, use the "unset
311 environment" command.
313 * Completion improvements
315 ** GDB can now complete function parameters in linespecs and
316 explicit locations without quoting. When setting breakpoints,
317 quoting around functions names to help with TAB-completion is
318 generally no longer necessary. For example, this now completes
321 (gdb) b function(in[TAB]
322 (gdb) b function(int)
324 Related, GDB is no longer confused with completing functions in
325 C++ anonymous namespaces:
328 (gdb) b (anonymous namespace)::[TAB][TAB]
329 (anonymous namespace)::a_function()
330 (anonymous namespace)::b_function()
332 ** GDB now has much improved linespec and explicit locations TAB
333 completion support, that better understands what you're
334 completing and offers better suggestions. For example, GDB no
335 longer offers data symbols as possible completions when you're
336 setting a breakpoint.
338 ** GDB now TAB-completes label symbol names.
340 ** The "complete" command now mimics TAB completion accurately.
342 * New command line options (gcore)
345 Dump all memory mappings.
347 * Breakpoints on C++ functions are now set on all scopes by default
349 By default, breakpoints on functions/methods are now interpreted as
350 specifying all functions with the given name ignoring missing
351 leading scopes (namespaces and classes).
353 For example, assuming a C++ program with symbols named:
358 both commands "break func()" and "break B::func()" set a breakpoint
361 You can use the new flag "-qualified" to override this. This makes
362 GDB interpret the specified function name as a complete
363 fully-qualified name instead. For example, using the same C++
364 program, the "break -q B::func" command sets a breakpoint on
365 "B::func", only. A parameter has been added to the Python
366 gdb.Breakpoint constructor to achieve the same result when creating
367 a breakpoint from Python.
369 * Breakpoints on functions marked with C++ ABI tags
371 GDB can now set breakpoints on functions marked with C++ ABI tags
372 (e.g., [abi:cxx11]). See here for a description of ABI tags:
373 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
375 Functions with a C++11 abi tag are demangled/displayed like this:
377 function[abi:cxx11](int)
380 You can now set a breakpoint on such functions simply as if they had
383 (gdb) b function(int)
385 Or if you need to disambiguate between tags, like:
387 (gdb) b function[abi:other_tag](int)
389 Tab completion was adjusted accordingly as well.
393 ** New events gdb.new_inferior, gdb.inferior_deleted, and
394 gdb.new_thread are emitted. See the manual for further
395 description of these.
397 ** A new function, "gdb.rbreak" has been added to the Python API.
398 This function allows the setting of a large number of breakpoints
399 via a regex pattern in Python. See the manual for further details.
401 ** Python breakpoints can now accept explicit locations. See the
402 manual for a further description of this feature.
405 * New features in the GDB remote stub, GDBserver
407 ** GDBserver is now able to start inferior processes with a
408 specified initial working directory.
410 The user can set the desired working directory to be used from
411 GDB using the new "set cwd" command.
413 ** New "--selftest" command line option runs some GDBserver self
414 tests. These self tests are disabled in releases.
416 ** On Unix systems, GDBserver now does globbing expansion and variable
417 substitution in inferior command line arguments.
419 This is done by starting inferiors using a shell, like GDB does.
420 See "set startup-with-shell" in the user manual for how to disable
421 this from GDB when using "target extended-remote". When using
422 "target remote", you can disable the startup with shell by using the
423 new "--no-startup-with-shell" GDBserver command line option.
425 ** On Unix systems, GDBserver now supports receiving environment
426 variables that are to be set or unset from GDB. These variables
427 will affect the environment to be passed to the inferior.
429 * When catching an Ada exception raised with a message, GDB now prints
430 the message in the catchpoint hit notification. In GDB/MI mode, that
431 information is provided as an extra field named "exception-message"
432 in the *stopped notification.
434 * Trait objects can now be inspected When debugging Rust code. This
435 requires compiler support which will appear in Rust 1.24.
439 QEnvironmentHexEncoded
440 Inform GDBserver of an environment variable that is to be passed to
441 the inferior when starting it.
444 Inform GDBserver of an environment variable that is to be unset
445 before starting the remote inferior.
448 Inform GDBserver that the environment should be reset (i.e.,
449 user-set environment variables should be unset).
452 Indicates whether the inferior must be started with a shell or not.
455 Tell GDBserver that the inferior to be started should use a specific
458 * The "maintenance print c-tdesc" command now takes an optional
459 argument which is the file name of XML target description.
461 * The "maintenance selftest" command now takes an optional argument to
462 filter the tests to be run.
464 * The "enable", and "disable" commands now accept a range of
465 breakpoint locations, e.g. "enable 1.3-5".
470 Set and show the current working directory for the inferior.
473 Set and show compilation command used for compiling and injecting code
474 with the 'compile' commands.
476 set debug separate-debug-file
477 show debug separate-debug-file
478 Control the display of debug output about separate debug file search.
480 set dump-excluded-mappings
481 show dump-excluded-mappings
482 Control whether mappings marked with the VM_DONTDUMP flag should be
483 dumped when generating a core file.
486 List the registered selftests.
489 Start the debugged program stopping at the first instruction.
492 Control display of debugging messages related to OpenRISC targets.
494 set|show print type nested-type-limit
495 Set and show the limit of nesting level for nested types that the
496 type printer will show.
498 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
501 * Safer/improved support for debugging with no debug info
503 GDB no longer assumes functions with no debug information return
506 This means that GDB now refuses to call such functions unless you
507 tell it the function's type, by either casting the call to the
508 declared return type, or by casting the function to a function
509 pointer of the right type, and calling that:
511 (gdb) p getenv ("PATH")
512 'getenv' has unknown return type; cast the call to its declared return type
513 (gdb) p (char *) getenv ("PATH")
514 $1 = 0x7fffffffe "/usr/local/bin:/"...
515 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
516 $2 = 0x7fffffffe "/usr/local/bin:/"...
518 Similarly, GDB no longer assumes that global variables with no debug
519 info have type 'int', and refuses to print the variable's value
520 unless you tell it the variable's type:
523 'var' has unknown type; cast it to its declared type
527 * New native configurations
529 FreeBSD/aarch64 aarch64*-*-freebsd*
530 FreeBSD/arm arm*-*-freebsd*
534 FreeBSD/aarch64 aarch64*-*-freebsd*
535 FreeBSD/arm arm*-*-freebsd*
536 OpenRISC ELF or1k*-*-elf
538 * Removed targets and native configurations
540 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
542 *** Changes in GDB 8.0
544 * GDB now supports access to the PKU register on GNU/Linux. The register is
545 added by the Memory Protection Keys for Userspace feature which will be
546 available in future Intel CPUs.
548 * GDB now supports C++11 rvalue references.
552 ** New functions to start, stop and access a running btrace recording.
553 ** Rvalue references are now supported in gdb.Type.
555 * GDB now supports recording and replaying rdrand and rdseed Intel 64
558 * Building GDB and GDBserver now requires a C++11 compiler.
560 For example, GCC 4.8 or later.
562 It is no longer possible to build GDB or GDBserver with a C
563 compiler. The --disable-build-with-cxx configure option has been
566 * Building GDB and GDBserver now requires GNU make >= 3.81.
568 It is no longer supported to build GDB or GDBserver with another
569 implementation of the make program or an earlier version of GNU make.
571 * Native debugging on MS-Windows supports command-line redirection
573 Command-line arguments used for starting programs on MS-Windows can
574 now include redirection symbols supported by native Windows shells,
575 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
576 as "run", "start", and "set args", as well as the corresponding MI
579 * Support for thread names on MS-Windows.
581 GDB now catches and handles the special exception that programs
582 running on MS-Windows use to assign names to threads in the
585 * Support for Java programs compiled with gcj has been removed.
587 * User commands now accept an unlimited number of arguments.
588 Previously, only up to 10 was accepted.
590 * The "eval" command now expands user-defined command arguments.
592 This makes it easier to process a variable number of arguments:
597 eval "print $arg%d", $i
602 * Target descriptions can now describe registers for sparc32 and sparc64.
604 * GDB now supports DWARF version 5 (debug information format).
605 Its .debug_names index is not yet supported.
607 * New native configurations
609 FreeBSD/mips mips*-*-freebsd
613 Synopsys ARC arc*-*-elf32
614 FreeBSD/mips mips*-*-freebsd
616 * Removed targets and native configurations
618 Alpha running FreeBSD alpha*-*-freebsd*
619 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
624 Erases all the flash memory regions reported by the target.
626 maint print arc arc-instruction address
627 Print internal disassembler information about instruction at a given address.
631 set disassembler-options
632 show disassembler-options
633 Controls the passing of target specific information to the disassembler.
634 If it is necessary to specify more than one disassembler option then
635 multiple options can be placed together into a comma separated list.
636 The default value is the empty string. Currently, the only supported
637 targets are ARM, PowerPC and S/390.
642 Erases all the flash memory regions reported by the target. This is
643 equivalent to the CLI command flash-erase.
645 -file-list-shared-libraries
646 List the shared libraries in the program. This is
647 equivalent to the CLI command "info shared".
650 Catchpoints stopping the program when Ada exceptions are
651 handled. This is equivalent to the CLI command "catch handlers".
653 *** Changes in GDB 7.12
655 * GDB and GDBserver now build with a C++ compiler by default.
657 The --enable-build-with-cxx configure option is now enabled by
658 default. One must now explicitly configure with
659 --disable-build-with-cxx in order to build with a C compiler. This
660 option will be removed in a future release.
662 * GDBserver now supports recording btrace without maintaining an active
665 * GDB now supports a negative repeat count in the 'x' command to examine
666 memory backward from the given address. For example:
669 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
670 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
671 (gdb) x/-5i 0x0000000000400580
672 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
673 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
674 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
675 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
676 0x40057b <main(int, char**)+25>:
677 callq 0x400536 <Func1(int, char const*)>
679 * Fortran: Support structures with fields of dynamic types and
680 arrays of dynamic types.
682 * The symbol dumping maintenance commands have new syntax.
683 maint print symbols [-pc address] [--] [filename]
684 maint print symbols [-objfile objfile] [-source source] [--] [filename]
685 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
686 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
687 maint print msymbols [-objfile objfile] [--] [filename]
689 * GDB now supports multibit bitfields and enums in target register
692 * New Python-based convenience function $_as_string(val), which returns
693 the textual representation of a value. This function is especially
694 useful to obtain the text label of an enum value.
696 * Intel MPX bound violation handling.
698 Segmentation faults caused by a Intel MPX boundary violation
699 now display the kind of violation (upper or lower), the memory
700 address accessed and the memory bounds, along with the usual
701 signal received and code location.
705 Program received signal SIGSEGV, Segmentation fault
706 Upper bound violation while accessing address 0x7fffffffc3b3
707 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
708 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
710 * Rust language support.
711 GDB now supports debugging programs written in the Rust programming
712 language. See https://www.rust-lang.org/ for more information about
715 * Support for running interpreters on specified input/output devices
717 GDB now supports a new mechanism that allows frontends to provide
718 fully featured GDB console views, as a better alternative to
719 building such views on top of the "-interpreter-exec console"
720 command. See the new "new-ui" command below. With that command,
721 frontends can now start GDB in the traditional command-line mode
722 running in an embedded terminal emulator widget, and create a
723 separate MI interpreter running on a specified i/o device. In this
724 way, GDB handles line editing, history, tab completion, etc. in the
725 console all by itself, and the GUI uses the separate MI interpreter
726 for its own control and synchronization, invisible to the command
729 * The "catch syscall" command catches groups of related syscalls.
731 The "catch syscall" command now supports catching a group of related
732 syscalls using the 'group:' or 'g:' prefix.
737 skip -gfile file-glob-pattern
738 skip -function function
739 skip -rfunction regular-expression
740 A generalized form of the skip command, with new support for
741 glob-style file names and regular expressions for function names.
742 Additionally, a file spec and a function spec may now be combined.
744 maint info line-table REGEXP
745 Display the contents of GDB's internal line table data struture.
748 Run any GDB unit tests that were compiled in.
751 Start a new user interface instance running INTERP as interpreter,
752 using the TTY file for input/output.
756 ** gdb.Breakpoint objects have a new attribute "pending", which
757 indicates whether the breakpoint is pending.
758 ** Three new breakpoint-related events have been added:
759 gdb.breakpoint_created, gdb.breakpoint_modified, and
760 gdb.breakpoint_deleted.
763 Signal ("set") the given MS-Windows event object. This is used in
764 conjunction with the Windows JIT debugging (AeDebug) support, where
765 the OS suspends a crashing process until a debugger can attach to
766 it. Resuming the crashing process, in order to debug it, is done by
769 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
770 was added in GDBserver, including JIT compiling fast tracepoint's
771 conditional expression bytecode into native code.
773 * Support for various remote target protocols and ROM monitors has
776 target m32rsdi Remote M32R debugging over SDI
777 target mips MIPS remote debugging protocol
778 target pmon PMON ROM monitor
779 target ddb NEC's DDB variant of PMON for Vr4300
780 target rockhopper NEC RockHopper variant of PMON
781 target lsi LSI variant of PMO
783 * Support for tracepoints and fast tracepoints on powerpc-linux,
784 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
785 including JIT compiling fast tracepoint's conditional expression
786 bytecode into native code.
788 * MI async record =record-started now includes the method and format used for
789 recording. For example:
791 =record-started,thread-group="i1",method="btrace",format="bts"
793 * MI async record =thread-selected now includes the frame field. For example:
795 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
799 Andes NDS32 nds32*-*-elf
801 *** Changes in GDB 7.11
803 * GDB now supports debugging kernel-based threads on FreeBSD.
805 * Per-inferior thread numbers
807 Thread numbers are now per inferior instead of global. If you're
808 debugging multiple inferiors, GDB displays thread IDs using a
809 qualified INF_NUM.THR_NUM form. For example:
813 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
814 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
815 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
816 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
818 As consequence, thread numbers as visible in the $_thread
819 convenience variable and in Python's InferiorThread.num attribute
820 are no longer unique between inferiors.
822 GDB now maintains a second thread ID per thread, referred to as the
823 global thread ID, which is the new equivalent of thread numbers in
824 previous releases. See also $_gthread below.
826 For backwards compatibility, MI's thread IDs always refer to global
829 * Commands that accept thread IDs now accept the qualified
830 INF_NUM.THR_NUM form as well. For example:
833 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
836 * In commands that accept a list of thread IDs, you can now refer to
837 all threads of an inferior using a star wildcard. GDB accepts
838 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
839 refer to all threads of the current inferior. For example, "info
842 * You can use "info threads -gid" to display the global thread ID of
845 * The new convenience variable $_gthread holds the global number of
848 * The new convenience variable $_inferior holds the number of the
851 * GDB now displays the ID and name of the thread that hit a breakpoint
852 or received a signal, if your program is multi-threaded. For
855 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
856 Thread 1 "main" received signal SIGINT, Interrupt.
858 * Record btrace now supports non-stop mode.
860 * Support for tracepoints on aarch64-linux was added in GDBserver.
862 * The 'record instruction-history' command now indicates speculative execution
863 when using the Intel Processor Trace recording format.
865 * GDB now allows users to specify explicit locations, bypassing
866 the linespec parser. This feature is also available to GDB/MI
869 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
870 GDB now is able to debug both AArch64 applications and ARM applications
873 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
874 including JIT compiling fast tracepoint's conditional expression bytecode
877 * GDB now supports displaced stepping on AArch64 GNU/Linux.
879 * "info threads", "info inferiors", "info display", "info checkpoints"
880 and "maint info program-spaces" now list the corresponding items in
881 ascending ID order, for consistency with all other "info" commands.
883 * In Ada, the overloads selection menu has been enhanced to display the
884 parameter types and the return types for the matching overloaded subprograms.
888 maint set target-non-stop (on|off|auto)
889 maint show target-non-stop
890 Control whether GDB targets always operate in non-stop mode even if
891 "set non-stop" is "off". The default is "auto", meaning non-stop
892 mode is enabled if supported by the target.
894 maint set bfd-sharing
895 maint show bfd-sharing
896 Control the reuse of bfd objects.
900 Control display of debugging info regarding bfd caching.
904 Control display of debugging info regarding FreeBSD threads.
906 set remote multiprocess-extensions-packet
907 show remote multiprocess-extensions-packet
908 Set/show the use of the remote protocol multiprocess extensions.
910 set remote thread-events
911 show remote thread-events
912 Set/show the use of thread create/exit events.
914 set ada print-signatures on|off
915 show ada print-signatures"
916 Control whether parameter types and return types are displayed in overloads
917 selection menus. It is activaled (@code{on}) by default.
921 Controls the maximum size of memory, in bytes, that GDB will
922 allocate for value contents. Prevents incorrect programs from
923 causing GDB to allocate overly large buffers. Default is 64k.
925 * The "disassemble" command accepts a new modifier: /s.
926 It prints mixed source+disassembly like /m with two differences:
927 - disassembled instructions are now printed in program order, and
928 - and source for all relevant files is now printed.
929 The "/m" option is now considered deprecated: its "source-centric"
930 output hasn't proved useful in practice.
932 * The "record instruction-history" command accepts a new modifier: /s.
933 It behaves exactly like /m and prints mixed source+disassembly.
935 * The "set scheduler-locking" command supports a new mode "replay".
936 It behaves like "off" in record mode and like "on" in replay mode.
938 * Support for various ROM monitors has been removed:
940 target dbug dBUG ROM monitor for Motorola ColdFire
941 target picobug Motorola picobug monitor
942 target dink32 DINK32 ROM monitor for PowerPC
943 target m32r Renesas M32R/D ROM monitor
944 target mon2000 mon2000 ROM monitor
945 target ppcbug PPCBUG ROM monitor for PowerPC
947 * Support for reading/writing memory and extracting values on architectures
948 whose memory is addressable in units of any integral multiple of 8 bits.
951 Allows to break when an Ada exception is handled.
956 Indicates that an exec system call was executed.
958 exec-events feature in qSupported
959 The qSupported packet allows GDB to request support for exec
960 events using the new 'gdbfeature' exec-event, and the qSupported
961 response can contain the corresponding 'stubfeature'. Set and
962 show commands can be used to display whether these features are enabled.
965 Equivalent to interrupting with the ^C character, but works in
968 thread created stop reason (T05 create:...)
969 Indicates that the thread was just created and is stopped at entry.
971 thread exit stop reply (w exitcode;tid)
972 Indicates that the thread has terminated.
975 Enables/disables thread create and exit event reporting. For
976 example, this is used in non-stop mode when GDB stops a set of
977 threads and synchronously waits for the their corresponding stop
978 replies. Without exit events, if one of the threads exits, GDB
979 would hang forever not knowing that it should no longer expect a
980 stop for that same thread.
983 Indicates that there are no resumed threads left in the target (all
984 threads are stopped). The remote stub reports support for this stop
985 reply to GDB's qSupported query.
988 Enables/disables catching syscalls from the inferior process.
989 The remote stub reports support for this packet to GDB's qSupported query.
991 syscall_entry stop reason
992 Indicates that a syscall was just called.
994 syscall_return stop reason
995 Indicates that a syscall just returned.
997 * Extended-remote exec events
999 ** GDB now has support for exec events on extended-remote Linux targets.
1000 For such targets with Linux kernels 2.5.46 and later, this enables
1001 follow-exec-mode and exec catchpoints.
1003 set remote exec-event-feature-packet
1004 show remote exec-event-feature-packet
1005 Set/show the use of the remote exec event feature.
1007 * Thread names in remote protocol
1009 The reply to qXfer:threads:read may now include a name attribute for each
1012 * Target remote mode fork and exec events
1014 ** GDB now has support for fork and exec events on target remote mode
1015 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1016 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1017 fork and exec catchpoints.
1019 * Remote syscall events
1021 ** GDB now has support for catch syscall on remote Linux targets,
1022 currently enabled on x86/x86_64 architectures.
1024 set remote catch-syscall-packet
1025 show remote catch-syscall-packet
1026 Set/show the use of the remote catch syscall feature.
1030 ** The -var-set-format command now accepts the zero-hexadecimal
1031 format. It outputs data in hexadecimal format with zero-padding on the
1036 ** gdb.InferiorThread objects have a new attribute "global_num",
1037 which refers to the thread's global thread ID. The existing
1038 "num" attribute now refers to the thread's per-inferior number.
1039 See "Per-inferior thread numbers" above.
1040 ** gdb.InferiorThread objects have a new attribute "inferior", which
1041 is the Inferior object the thread belongs to.
1043 *** Changes in GDB 7.10
1045 * Support for process record-replay and reverse debugging on aarch64*-linux*
1046 targets has been added. GDB now supports recording of A64 instruction set
1047 including advance SIMD instructions.
1049 * Support for Sun's version of the "stabs" debug file format has been removed.
1051 * GDB now honors the content of the file /proc/PID/coredump_filter
1052 (PID is the process ID) on GNU/Linux systems. This file can be used
1053 to specify the types of memory mappings that will be included in a
1054 corefile. For more information, please refer to the manual page of
1055 "core(5)". GDB also has a new command: "set use-coredump-filter
1056 on|off". It allows to set whether GDB will read the content of the
1057 /proc/PID/coredump_filter file when generating a corefile.
1059 * The "info os" command on GNU/Linux can now display information on
1061 "info os cpus" Listing of all cpus/cores on the system
1063 * GDB has two new commands: "set serial parity odd|even|none" and
1064 "show serial parity". These allows to set or show parity for the
1067 * The "info source" command now displays the producer string if it was
1068 present in the debug info. This typically includes the compiler version
1069 and may include things like its command line arguments.
1071 * The "info dll", an alias of the "info sharedlibrary" command,
1072 is now available on all platforms.
1074 * Directory names supplied to the "set sysroot" commands may be
1075 prefixed with "target:" to tell GDB to access shared libraries from
1076 the target system, be it local or remote. This replaces the prefix
1077 "remote:". The default sysroot has been changed from "" to
1078 "target:". "remote:" is automatically converted to "target:" for
1079 backward compatibility.
1081 * The system root specified by "set sysroot" will be prepended to the
1082 filename of the main executable (if reported to GDB as absolute by
1083 the operating system) when starting processes remotely, and when
1084 attaching to already-running local or remote processes.
1086 * GDB now supports automatic location and retrieval of executable
1087 files from remote targets. Remote debugging can now be initiated
1088 using only a "target remote" or "target extended-remote" command
1089 (no "set sysroot" or "file" commands are required). See "New remote
1092 * The "dump" command now supports verilog hex format.
1094 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1096 * On GNU/Linux, GDB and gdbserver are now able to access executable
1097 and shared library files without a "set sysroot" command when
1098 attaching to processes running in different mount namespaces from
1099 the debugger. This makes it possible to attach to processes in
1100 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1101 See "New remote packets" below.
1103 * The "tui reg" command now provides completion for all of the
1104 available register groups, including target specific groups.
1106 * The HISTSIZE environment variable is no longer read when determining
1107 the size of GDB's command history. GDB now instead reads the dedicated
1108 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1109 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1114 ** Memory ports can now be unbuffered.
1118 ** gdb.Objfile objects have a new attribute "username",
1119 which is the name of the objfile as specified by the user,
1120 without, for example, resolving symlinks.
1121 ** You can now write frame unwinders in Python.
1122 ** gdb.Type objects have a new method "optimized_out",
1123 returning optimized out gdb.Value instance of this type.
1124 ** gdb.Value objects have new methods "reference_value" and
1125 "const_value" which return a reference to the value and a
1126 "const" version of the value respectively.
1130 maint print symbol-cache
1131 Print the contents of the symbol cache.
1133 maint print symbol-cache-statistics
1134 Print statistics of symbol cache usage.
1136 maint flush-symbol-cache
1137 Flush the contents of the symbol cache.
1141 Start branch trace recording using Branch Trace Store (BTS) format.
1144 Evaluate expression by using the compiler and print result.
1148 Explicit commands for enabling and disabling tui mode.
1151 set mpx bound on i386 and amd64
1152 Support for bound table investigation on Intel MPX enabled applications.
1156 Start branch trace recording using Intel Processor Trace format.
1159 Print information about branch tracing internals.
1161 maint btrace packet-history
1162 Print the raw branch tracing data.
1164 maint btrace clear-packet-history
1165 Discard the stored raw branch tracing data.
1168 Discard all branch tracing data. It will be fetched and processed
1169 anew by the next "record" command.
1174 Renamed from "set debug dwarf2-die".
1175 show debug dwarf-die
1176 Renamed from "show debug dwarf2-die".
1178 set debug dwarf-read
1179 Renamed from "set debug dwarf2-read".
1180 show debug dwarf-read
1181 Renamed from "show debug dwarf2-read".
1183 maint set dwarf always-disassemble
1184 Renamed from "maint set dwarf2 always-disassemble".
1185 maint show dwarf always-disassemble
1186 Renamed from "maint show dwarf2 always-disassemble".
1188 maint set dwarf max-cache-age
1189 Renamed from "maint set dwarf2 max-cache-age".
1190 maint show dwarf max-cache-age
1191 Renamed from "maint show dwarf2 max-cache-age".
1193 set debug dwarf-line
1194 show debug dwarf-line
1195 Control display of debugging info regarding DWARF line processing.
1198 show max-completions
1199 Set the maximum number of candidates to be considered during
1200 completion. The default value is 200. This limit allows GDB
1201 to avoid generating large completion lists, the computation of
1202 which can cause the debugger to become temporarily unresponsive.
1204 set history remove-duplicates
1205 show history remove-duplicates
1206 Control the removal of duplicate history entries.
1208 maint set symbol-cache-size
1209 maint show symbol-cache-size
1210 Control the size of the symbol cache.
1212 set|show record btrace bts buffer-size
1213 Set and show the size of the ring buffer used for branch tracing in
1215 The obtained size may differ from the requested size. Use "info
1216 record" to see the obtained buffer size.
1218 set debug linux-namespaces
1219 show debug linux-namespaces
1220 Control display of debugging info regarding Linux namespaces.
1222 set|show record btrace pt buffer-size
1223 Set and show the size of the ring buffer used for branch tracing in
1224 Intel Processor Trace format.
1225 The obtained size may differ from the requested size. Use "info
1226 record" to see the obtained buffer size.
1228 maint set|show btrace pt skip-pad
1229 Set and show whether PAD packets are skipped when computing the
1232 * The command 'thread apply all' can now support new option '-ascending'
1233 to call its specified command for all threads in ascending order.
1235 * Python/Guile scripting
1237 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1238 special section named `.debug_gdb_scripts'.
1240 * New remote packets
1242 qXfer:btrace-conf:read
1243 Return the branch trace configuration for the current thread.
1245 Qbtrace-conf:bts:size
1246 Set the requested ring buffer size for branch tracing in BTS format.
1249 Enable Intel Procesor Trace-based branch tracing for the current
1250 process. The remote stub reports support for this packet to GDB's
1253 Qbtrace-conf:pt:size
1254 Set the requested ring buffer size for branch tracing in Intel Processor
1258 Indicates a memory breakpoint instruction was executed, irrespective
1259 of whether it was GDB that planted the breakpoint or the breakpoint
1260 is hardcoded in the program. This is required for correct non-stop
1264 Indicates the target stopped for a hardware breakpoint. This is
1265 required for correct non-stop mode operation.
1268 Return information about files on the remote system.
1270 qXfer:exec-file:read
1271 Return the full absolute name of the file that was executed to
1272 create a process running on the remote system.
1275 Select the filesystem on which vFile: operations with filename
1276 arguments will operate. This is required for GDB to be able to
1277 access files on remote targets where the remote stub does not
1278 share a common filesystem with the inferior(s).
1281 Indicates that a fork system call was executed.
1284 Indicates that a vfork system call was executed.
1286 vforkdone stop reason
1287 Indicates that a vfork child of the specified process has executed
1288 an exec or exit, allowing the vfork parent to resume execution.
1290 fork-events and vfork-events features in qSupported
1291 The qSupported packet allows GDB to request support for fork and
1292 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1293 and the qSupported response can contain the corresponding
1294 'stubfeatures'. Set and show commands can be used to display
1295 whether these features are enabled.
1297 * Extended-remote fork events
1299 ** GDB now has support for fork events on extended-remote Linux
1300 targets. For targets with Linux kernels 2.5.60 and later, this
1301 enables follow-fork-mode and detach-on-fork for both fork and
1302 vfork, as well as fork and vfork catchpoints.
1304 * The info record command now shows the recording format and the
1305 branch tracing configuration for the current thread when using
1306 the btrace record target.
1307 For the BTS format, it shows the ring buffer size.
1309 * GDB now has support for DTrace USDT (Userland Static Defined
1310 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1312 * GDB now supports access to vector registers on S/390 GNU/Linux
1315 * Removed command line options
1317 -xdb HP-UX XDB compatibility mode.
1319 * Removed targets and native configurations
1321 HP/PA running HP-UX hppa*-*-hpux*
1322 Itanium running HP-UX ia64-*-hpux*
1324 * New configure options
1327 This configure option allows the user to build GDB with support for
1328 Intel Processor Trace (default: auto). This requires libipt.
1330 --with-libipt-prefix=PATH
1331 Specify the path to the version of libipt that GDB should use.
1332 $PATH/include should contain the intel-pt.h header and
1333 $PATH/lib should contain the libipt.so library.
1335 *** Changes in GDB 7.9.1
1339 ** Xmethods can now specify a result type.
1341 *** Changes in GDB 7.9
1343 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1347 ** You can now access frame registers from Python scripts.
1348 ** New attribute 'producer' for gdb.Symtab objects.
1349 ** gdb.Objfile objects have a new attribute "progspace",
1350 which is the gdb.Progspace object of the containing program space.
1351 ** gdb.Objfile objects have a new attribute "owner".
1352 ** gdb.Objfile objects have a new attribute "build_id",
1353 which is the build ID generated when the file was built.
1354 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1355 ** A new event "gdb.clear_objfiles" has been added, triggered when
1356 selecting a new file to debug.
1357 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1358 ** New function gdb.lookup_objfile.
1360 New events which are triggered when GDB modifies the state of the
1363 ** gdb.events.inferior_call_pre: Function call is about to be made.
1364 ** gdb.events.inferior_call_post: Function call has just been made.
1365 ** gdb.events.memory_changed: A memory location has been altered.
1366 ** gdb.events.register_changed: A register has been altered.
1368 * New Python-based convenience functions:
1370 ** $_caller_is(name [, number_of_frames])
1371 ** $_caller_matches(regexp [, number_of_frames])
1372 ** $_any_caller_is(name [, number_of_frames])
1373 ** $_any_caller_matches(regexp [, number_of_frames])
1375 * GDB now supports the compilation and injection of source code into
1376 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1377 to compile the source code to object code, and if successful, inject
1378 and execute that code within the current context of the inferior.
1379 Currently the C language is supported. The commands used to
1380 interface with this new feature are:
1382 compile code [-raw|-r] [--] [source code]
1383 compile file [-raw|-r] filename
1387 demangle [-l language] [--] name
1388 Demangle "name" in the specified language, or the current language
1389 if elided. This command is renamed from the "maint demangle" command.
1390 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1391 as "maint demangler-warning".
1393 queue-signal signal-name-or-number
1394 Queue a signal to be delivered to the thread when it is resumed.
1396 add-auto-load-scripts-directory directory
1397 Add entries to the list of directories from which to load auto-loaded
1400 maint print user-registers
1401 List all currently available "user" registers.
1403 compile code [-r|-raw] [--] [source code]
1404 Compile, inject, and execute in the inferior the executable object
1405 code produced by compiling the provided source code.
1407 compile file [-r|-raw] filename
1408 Compile and inject into the inferior the executable object code
1409 produced by compiling the source code stored in the filename
1412 * On resume, GDB now always passes the signal the program had stopped
1413 for to the thread the signal was sent to, even if the user changed
1414 threads before resuming. Previously GDB would often (but not
1415 always) deliver the signal to the thread that happens to be current
1418 * Conversely, the "signal" command now consistently delivers the
1419 requested signal to the current thread. GDB now asks for
1420 confirmation if the program had stopped for a signal and the user
1421 switched threads meanwhile.
1423 * "breakpoint always-inserted" modes "off" and "auto" merged.
1425 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1426 won't remove breakpoints from the target until all threads stop,
1427 even in non-stop mode. The "auto" mode has been removed, and "off"
1428 is now the default mode.
1432 set debug symbol-lookup
1433 show debug symbol-lookup
1434 Control display of debugging info regarding symbol lookup.
1438 ** The -list-thread-groups command outputs an exit-code field for
1439 inferiors that have exited.
1443 MIPS SDE mips*-sde*-elf*
1447 Support for these obsolete configurations has been removed.
1449 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1450 SGI Irix-5.x mips-*-irix5*
1451 SGI Irix-6.x mips-*-irix6*
1452 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1453 VAX running Ultrix vax-*-ultrix*
1455 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1456 and "assf"), have been removed. Use the "sharedlibrary" command, or
1457 its alias "share", instead.
1459 *** Changes in GDB 7.8
1461 * New command line options
1464 This is an alias for the --data-directory option.
1466 * GDB supports printing and modifying of variable length automatic arrays
1467 as specified in ISO C99.
1469 * The ARM simulator now supports instruction level tracing
1470 with or without disassembly.
1474 GDB now has support for scripting using Guile. Whether this is
1475 available is determined at configure time.
1476 Guile version 2.0 or greater is required.
1477 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1479 * New commands (for set/show, see "New options" below)
1483 Invoke CODE by passing it to the Guile interpreter.
1487 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1489 info auto-load guile-scripts [regexp]
1490 Print the list of automatically loaded Guile scripts.
1492 * The source command is now capable of sourcing Guile scripts.
1493 This feature is dependent on the debugger being built with Guile support.
1497 set print symbol-loading (off|brief|full)
1498 show print symbol-loading
1499 Control whether to print informational messages when loading symbol
1500 information for a file. The default is "full", but when debugging
1501 programs with large numbers of shared libraries the amount of output
1502 becomes less useful.
1504 set guile print-stack (none|message|full)
1505 show guile print-stack
1506 Show a stack trace when an error is encountered in a Guile script.
1508 set auto-load guile-scripts (on|off)
1509 show auto-load guile-scripts
1510 Control auto-loading of Guile script files.
1512 maint ada set ignore-descriptive-types (on|off)
1513 maint ada show ignore-descriptive-types
1514 Control whether the debugger should ignore descriptive types in Ada
1515 programs. The default is not to ignore the descriptive types. See
1516 the user manual for more details on descriptive types and the intended
1517 usage of this option.
1519 set auto-connect-native-target
1521 Control whether GDB is allowed to automatically connect to the
1522 native target for the run, attach, etc. commands when not connected
1523 to any target yet. See also "target native" below.
1525 set record btrace replay-memory-access (read-only|read-write)
1526 show record btrace replay-memory-access
1527 Control what memory accesses are allowed during replay.
1529 maint set target-async (on|off)
1530 maint show target-async
1531 This controls whether GDB targets operate in synchronous or
1532 asynchronous mode. Normally the default is asynchronous, if it is
1533 available; but this can be changed to more easily debug problems
1534 occurring only in synchronous mode.
1536 set mi-async (on|off)
1538 Control whether MI asynchronous mode is preferred. This supersedes
1539 "set target-async" of previous GDB versions.
1541 * "set target-async" is deprecated as a CLI option and is now an alias
1542 for "set mi-async" (only puts MI into async mode).
1544 * Background execution commands (e.g., "c&", "s&", etc.) are now
1545 possible ``out of the box'' if the target supports them. Previously
1546 the user would need to explicitly enable the possibility with the
1547 "set target-async on" command.
1549 * New features in the GDB remote stub, GDBserver
1551 ** New option --debug-format=option1[,option2,...] allows one to add
1552 additional text to each output. At present only timestamps
1553 are supported: --debug-format=timestamps.
1554 Timestamps can also be turned on with the
1555 "monitor set debug-format timestamps" command from GDB.
1557 * The 'record instruction-history' command now starts counting instructions
1558 at one. This also affects the instruction ranges reported by the
1559 'record function-call-history' command when given the /i modifier.
1561 * The command 'record function-call-history' supports a new modifier '/c' to
1562 indent the function names based on their call stack depth.
1563 The fields for the '/i' and '/l' modifier have been reordered.
1564 The source line range is now prefixed with 'at'.
1565 The instruction range is now prefixed with 'inst'.
1566 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1567 "record instruction-history" and "list" commands.
1569 * The ranges given as arguments to the 'record function-call-history' and
1570 'record instruction-history' commands are now inclusive.
1572 * The btrace record target now supports the 'record goto' command.
1573 For locations inside the execution trace, the back trace is computed
1574 based on the information stored in the execution trace.
1576 * The btrace record target supports limited reverse execution and replay.
1577 The target does not record data and therefore does not allow reading
1578 memory or registers.
1580 * The "catch syscall" command now works on s390*-linux* targets.
1582 * The "compare-sections" command is no longer specific to target
1583 remote. It now works with all targets.
1585 * All native targets are now consistently called "native".
1586 Consequently, the "target child", "target GNU", "target djgpp",
1587 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1588 commands have been replaced with "target native". The QNX/NTO port
1589 leaves the "procfs" target in place and adds a "native" target for
1590 consistency with other ports. The impact on users should be minimal
1591 as these commands previously either throwed an error, or were
1592 no-ops. The target's name is visible in the output of the following
1593 commands: "help target", "info target", "info files", "maint print
1596 * The "target native" command now connects to the native target. This
1597 can be used to launch native programs even when "set
1598 auto-connect-native-target" is set to off.
1600 * GDB now supports access to Intel MPX registers on GNU/Linux.
1602 * Support for Intel AVX-512 registers on GNU/Linux.
1603 Support displaying and modifying Intel AVX-512 registers
1604 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1606 * New remote packets
1608 qXfer:btrace:read's annex
1609 The qXfer:btrace:read packet supports a new annex 'delta' to read
1610 branch trace incrementally.
1614 ** Valid Python operations on gdb.Value objects representing
1615 structs/classes invoke the corresponding overloaded operators if
1617 ** New `Xmethods' feature in the Python API. Xmethods are
1618 additional methods or replacements for existing methods of a C++
1619 class. This feature is useful for those cases where a method
1620 defined in C++ source code could be inlined or optimized out by
1621 the compiler, making it unavailable to GDB.
1624 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1626 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1627 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1628 its alias "share", instead.
1630 * The commands "set remotebaud" and "show remotebaud" are no longer
1631 supported. Use "set serial baud" and "show serial baud" (respectively)
1636 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1637 target-async". The latter is left as a deprecated alias of the
1638 former for backward compatibility. If the target supports it,
1639 CLI background execution commands are now always possible by
1640 default, independently of whether the frontend stated a
1641 preference for asynchronous execution with "-gdb-set mi-async".
1642 Previously "-gdb-set target-async off" affected both MI execution
1643 commands and CLI execution commands.
1645 *** Changes in GDB 7.7
1647 * Improved support for process record-replay and reverse debugging on
1648 arm*-linux* targets. Support for thumb32 and syscall instruction
1649 recording has been added.
1651 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1653 * GDB now supports Fission DWP file format version 2.
1654 http://gcc.gnu.org/wiki/DebugFission
1656 * New convenience function "$_isvoid", to check whether an expression
1657 is void. A void expression is an expression where the type of the
1658 result is "void". For example, some convenience variables may be
1659 "void" when evaluated (e.g., "$_exitcode" before the execution of
1660 the program being debugged; or an undefined convenience variable).
1661 Another example, when calling a function whose return type is
1664 * The "maintenance print objfiles" command now takes an optional regexp.
1666 * The "catch syscall" command now works on arm*-linux* targets.
1668 * GDB now consistently shows "<not saved>" when printing values of
1669 registers the debug info indicates have not been saved in the frame
1670 and there's nowhere to retrieve them from
1671 (callee-saved/call-clobbered registers):
1676 (gdb) info registers rax
1679 Before, the former would print "<optimized out>", and the latter
1680 "*value not available*".
1682 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1687 ** Frame filters and frame decorators have been added.
1688 ** Temporary breakpoints are now supported.
1689 ** Line tables representation has been added.
1690 ** New attribute 'parent_type' for gdb.Field objects.
1691 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1692 ** New attribute 'name' for gdb.Type objects.
1696 Nios II ELF nios2*-*-elf
1697 Nios II GNU/Linux nios2*-*-linux
1698 Texas Instruments MSP430 msp430*-*-elf
1700 * Removed native configurations
1702 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1703 been removed. ELF variants of these configurations are kept supported.
1705 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1706 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1707 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1708 i[34567]86-*-openbsd3.[0-3]
1709 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1710 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1711 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1715 Like "catch throw", but catches a re-thrown exception.
1716 maint check-psymtabs
1717 Renamed from old "maint check-symtabs".
1719 Perform consistency checks on symtabs.
1720 maint expand-symtabs
1721 Expand symtabs matching an optional regexp.
1724 Display the details of GDB configure-time options.
1726 maint set|show per-command
1727 maint set|show per-command space
1728 maint set|show per-command time
1729 maint set|show per-command symtab
1730 Enable display of per-command gdb resource usage.
1732 remove-symbol-file FILENAME
1733 remove-symbol-file -a ADDRESS
1734 Remove a symbol file added via add-symbol-file. The file to remove
1735 can be identified by its filename or by an address that lies within
1736 the boundaries of this symbol file in memory.
1739 info exceptions REGEXP
1740 Display the list of Ada exceptions defined in the program being
1741 debugged. If provided, only the exceptions whose names match REGEXP
1746 set debug symfile off|on
1748 Control display of debugging info regarding reading symbol files and
1749 symbol tables within those files
1751 set print raw frame-arguments
1752 show print raw frame-arguments
1753 Set/show whether to print frame arguments in raw mode,
1754 disregarding any defined pretty-printers.
1756 set remote trace-status-packet
1757 show remote trace-status-packet
1758 Set/show the use of remote protocol qTStatus packet.
1762 Control display of debugging messages related to Nios II targets.
1766 Control whether target-assisted range stepping is enabled.
1768 set startup-with-shell
1769 show startup-with-shell
1770 Specifies whether Unix child processes are started via a shell or
1775 Use the target memory cache for accesses to the code segment. This
1776 improves performance of remote debugging (particularly disassembly).
1778 * You can now use a literal value 'unlimited' for options that
1779 interpret 0 or -1 as meaning "unlimited". E.g., "set
1780 trace-buffer-size unlimited" is now an alias for "set
1781 trace-buffer-size -1" and "set height unlimited" is now an alias for
1784 * The "set debug symtab-create" debugging option of GDB has been changed to
1785 accept a verbosity level. 0 means "off", 1 provides basic debugging
1786 output, and values of 2 or greater provides more verbose output.
1788 * New command-line options
1790 Display the details of GDB configure-time options.
1792 * The command 'tsave' can now support new option '-ctf' to save trace
1793 buffer in Common Trace Format.
1795 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1798 * GDB now implements the the C++ 'typeid' operator.
1800 * The new convenience variable $_exception holds the exception being
1801 thrown or caught at an exception-related catchpoint.
1803 * The exception-related catchpoints, like "catch throw", now accept a
1804 regular expression which can be used to filter exceptions by type.
1806 * The new convenience variable $_exitsignal is automatically set to
1807 the terminating signal number when the program being debugged dies
1808 due to an uncaught signal.
1812 ** All MI commands now accept an optional "--language" option.
1813 Support for this feature can be verified by using the "-list-features"
1814 command, which should contain "language-option".
1816 ** The new command -info-gdb-mi-command allows the user to determine
1817 whether a GDB/MI command is supported or not.
1819 ** The "^error" result record returned when trying to execute an undefined
1820 GDB/MI command now provides a variable named "code" whose content is the
1821 "undefined-command" error code. Support for this feature can be verified
1822 by using the "-list-features" command, which should contain
1823 "undefined-command-error-code".
1825 ** The -trace-save MI command can optionally save trace buffer in Common
1828 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1830 ** The command -data-list-register-values now accepts an optional
1831 "--skip-unavailable" option. When used, only the available registers
1834 ** The new command -trace-frame-collected dumps collected variables,
1835 computed expressions, tvars, memory and registers in a traceframe.
1837 ** The commands -stack-list-locals, -stack-list-arguments and
1838 -stack-list-variables now accept an option "--skip-unavailable".
1839 When used, only the available locals or arguments are displayed.
1841 ** The -exec-run command now accepts an optional "--start" option.
1842 When used, the command follows the same semantics as the "start"
1843 command, stopping the program's execution at the start of its
1844 main subprogram. Support for this feature can be verified using
1845 the "-list-features" command, which should contain
1846 "exec-run-start-option".
1848 ** The new commands -catch-assert and -catch-exceptions insert
1849 catchpoints stopping the program when Ada exceptions are raised.
1851 ** The new command -info-ada-exceptions provides the equivalent of
1852 the new "info exceptions" command.
1854 * New system-wide configuration scripts
1855 A GDB installation now provides scripts suitable for use as system-wide
1856 configuration scripts for the following systems:
1860 * GDB now supports target-assigned range stepping with remote targets.
1861 This improves the performance of stepping source lines by reducing
1862 the number of control packets from/to GDB. See "New remote packets"
1865 * GDB now understands the element 'tvar' in the XML traceframe info.
1866 It has the id of the collected trace state variables.
1868 * On S/390 targets that provide the transactional-execution feature,
1869 the program interruption transaction diagnostic block (TDB) is now
1870 represented as a number of additional "registers" in GDB.
1872 * New remote packets
1876 The vCont packet supports a new 'r' action, that tells the remote
1877 stub to step through an address range itself, without GDB
1878 involvemement at each single-step.
1880 qXfer:libraries-svr4:read's annex
1881 The previously unused annex of the qXfer:libraries-svr4:read packet
1882 is now used to support passing an argument list. The remote stub
1883 reports support for this argument list to GDB's qSupported query.
1884 The defined arguments are "start" and "prev", used to reduce work
1885 necessary for library list updating, resulting in significant
1888 * New features in the GDB remote stub, GDBserver
1890 ** GDBserver now supports target-assisted range stepping. Currently
1891 enabled on x86/x86_64 GNU/Linux targets.
1893 ** GDBserver now adds element 'tvar' in the XML in the reply to
1894 'qXfer:traceframe-info:read'. It has the id of the collected
1895 trace state variables.
1897 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1900 * New 'z' formatter for printing and examining memory, this displays the
1901 value as hexadecimal zero padded on the left to the size of the type.
1903 * GDB can now use Windows x64 unwinding data.
1905 * The "set remotebaud" command has been replaced by "set serial baud".
1906 Similarly, "show remotebaud" has been replaced by "show serial baud".
1907 The "set remotebaud" and "show remotebaud" commands are still available
1908 to provide backward compatibility with older versions of GDB.
1910 *** Changes in GDB 7.6
1912 * Target record has been renamed to record-full.
1913 Record/replay is now enabled with the "record full" command.
1914 This also affects settings that are associated with full record/replay
1915 that have been moved from "set/show record" to "set/show record full":
1917 set|show record full insn-number-max
1918 set|show record full stop-at-limit
1919 set|show record full memory-query
1921 * A new record target "record-btrace" has been added. The new target
1922 uses hardware support to record the control-flow of a process. It
1923 does not support replaying the execution, but it implements the
1924 below new commands for investigating the recorded execution log.
1925 This new recording method can be enabled using:
1929 The "record-btrace" target is only available on Intel Atom processors
1930 and requires a Linux kernel 2.6.32 or later.
1932 * Two new commands have been added for record/replay to give information
1933 about the recorded execution without having to replay the execution.
1934 The commands are only supported by "record btrace".
1936 record instruction-history prints the execution history at
1937 instruction granularity
1939 record function-call-history prints the execution history at
1940 function granularity
1942 * New native configurations
1944 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1945 FreeBSD/powerpc powerpc*-*-freebsd
1946 x86_64/Cygwin x86_64-*-cygwin*
1947 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1951 ARM AArch64 aarch64*-*-elf
1952 ARM AArch64 GNU/Linux aarch64*-*-linux
1953 Lynx 178 PowerPC powerpc-*-lynx*178
1954 x86_64/Cygwin x86_64-*-cygwin*
1955 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1957 * If the configured location of system.gdbinit file (as given by the
1958 --with-system-gdbinit option at configure time) is in the
1959 data-directory (as specified by --with-gdb-datadir at configure
1960 time) or in one of its subdirectories, then GDB will look for the
1961 system-wide init file in the directory specified by the
1962 --data-directory command-line option.
1964 * New command line options:
1966 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1967 other initialization files, unlike -nx which disables all of them.
1969 * Removed command line options
1971 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1974 * The 'ptype' and 'whatis' commands now accept an argument to control
1977 * 'info proc' now works on some core files.
1981 ** Vectors can be created with gdb.Type.vector.
1983 ** Python's atexit.register now works in GDB.
1985 ** Types can be pretty-printed via a Python API.
1987 ** Python 3 is now supported (in addition to Python 2.4 or later)
1989 ** New class gdb.Architecture exposes GDB's internal representation
1990 of architecture in the Python API.
1992 ** New method Frame.architecture returns the gdb.Architecture object
1993 corresponding to the frame's architecture.
1995 * New Python-based convenience functions:
1997 ** $_memeq(buf1, buf2, length)
1998 ** $_streq(str1, str2)
2000 ** $_regex(str, regex)
2002 * The 'cd' command now defaults to using '~' (the home directory) if not
2005 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2006 default for GCC since November 2000.
2008 * The command 'forward-search' can now be abbreviated as 'fo'.
2010 * The command 'info tracepoints' can now display 'installed on target'
2011 or 'not installed on target' for each non-pending location of tracepoint.
2013 * New configure options
2015 --enable-libmcheck/--disable-libmcheck
2016 By default, development versions are built with -lmcheck on hosts
2017 that support it, in order to help track memory corruption issues.
2018 Release versions, on the other hand, are built without -lmcheck
2019 by default. The --enable-libmcheck/--disable-libmcheck configure
2020 options allow the user to override that default.
2021 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2022 This configure option allows the user to build GDB with
2023 libbabeltrace using which GDB can read Common Trace Format data.
2025 * New commands (for set/show, see "New options" below)
2028 Catch signals. This is similar to "handle", but allows commands and
2029 conditions to be attached.
2032 List the BFDs known to GDB.
2034 python-interactive [command]
2036 Start a Python interactive prompt, or evaluate the optional command
2037 and print the result of expressions.
2040 "py" is a new alias for "python".
2042 enable type-printer [name]...
2043 disable type-printer [name]...
2044 Enable or disable type printers.
2048 ** For the Renesas Super-H architecture, the "regs" command has been removed
2049 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2054 set print type methods (on|off)
2055 show print type methods
2056 Control whether method declarations are displayed by "ptype".
2057 The default is to show them.
2059 set print type typedefs (on|off)
2060 show print type typedefs
2061 Control whether typedef definitions are displayed by "ptype".
2062 The default is to show them.
2064 set filename-display basename|relative|absolute
2065 show filename-display
2066 Control the way in which filenames is displayed.
2067 The default is "relative", which preserves previous behavior.
2069 set trace-buffer-size
2070 show trace-buffer-size
2071 Request target to change the size of trace buffer.
2073 set remote trace-buffer-size-packet auto|on|off
2074 show remote trace-buffer-size-packet
2075 Control the use of the remote protocol `QTBuffer:size' packet.
2079 Control display of debugging messages related to ARM AArch64.
2082 set debug coff-pe-read
2083 show debug coff-pe-read
2084 Control display of debugging messages related to reading of COFF/PE
2089 Control display of debugging messages related to Mach-O symbols
2092 set debug notification
2093 show debug notification
2094 Control display of debugging info for async remote notification.
2098 ** Command parameter changes are now notified using new async record
2099 "=cmd-param-changed".
2100 ** Trace frame changes caused by command "tfind" are now notified using
2101 new async record "=traceframe-changed".
2102 ** The creation, deletion and modification of trace state variables
2103 are now notified using new async records "=tsv-created",
2104 "=tsv-deleted" and "=tsv-modified".
2105 ** The start and stop of process record are now notified using new
2106 async record "=record-started" and "=record-stopped".
2107 ** Memory changes are now notified using new async record
2109 ** The data-disassemble command response will include a "fullname" field
2110 containing the absolute file name when source has been requested.
2111 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2112 command, to allow pattern filling of memory areas.
2113 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2114 library load/unload events.
2115 ** The response to breakpoint commands and breakpoint async records
2116 includes an "installed" field containing a boolean state about each
2117 non-pending tracepoint location is whether installed on target or not.
2118 ** Output of the "-trace-status" command includes a "trace-file" field
2119 containing the name of the trace file being examined. This field is
2120 optional, and only present when examining a trace file.
2121 ** The "fullname" field is now always present along with the "file" field,
2122 even if the file cannot be found by GDB.
2124 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2125 You must have the LZMA library available when configuring GDB for this
2126 feature to be enabled. For more information, see:
2127 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2129 * New remote packets
2132 Set the size of trace buffer. The remote stub reports support for this
2133 packet to gdb's qSupported query.
2136 Enable Branch Trace Store (BTS)-based branch tracing for the current
2137 thread. The remote stub reports support for this packet to gdb's
2141 Disable branch tracing for the current thread. The remote stub reports
2142 support for this packet to gdb's qSupported query.
2145 Read the traced branches for the current thread. The remote stub
2146 reports support for this packet to gdb's qSupported query.
2148 *** Changes in GDB 7.5
2150 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2151 for more x32 ABI info.
2153 * GDB now supports access to MIPS DSP registers on Linux targets.
2155 * GDB now supports debugging microMIPS binaries.
2157 * The "info os" command on GNU/Linux can now display information on
2158 several new classes of objects managed by the operating system:
2159 "info os procgroups" lists process groups
2160 "info os files" lists file descriptors
2161 "info os sockets" lists internet-domain sockets
2162 "info os shm" lists shared-memory regions
2163 "info os semaphores" lists semaphores
2164 "info os msg" lists message queues
2165 "info os modules" lists loaded kernel modules
2167 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2168 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2169 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2170 options and inspect the probe arguments using the new $_probe_arg family
2171 of convenience variables. You can obtain more information about SystemTap
2172 in <http://sourceware.org/systemtap/>.
2174 * GDB now supports reversible debugging on ARM, it allows you to
2175 debug basic ARM and THUMB instructions, and provides
2176 record/replay support.
2178 * The option "symbol-reloading" has been deleted as it is no longer used.
2182 ** GDB commands implemented in Python can now be put in command class
2185 ** The "maint set python print-stack on|off" is now deleted.
2187 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2188 apply "flag enum"-style pretty-printing to any enum.
2190 ** gdb.lookup_symbol can now work when there is no current frame.
2192 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2193 the source at which the symbol was defined.
2195 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2196 method 'value'. The former indicates whether the symbol needs a
2197 frame in order to compute its value, and the latter computes the
2200 ** A new method 'referenced_value' on gdb.Value objects which can
2201 dereference pointer as well as C++ reference values.
2203 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2204 which return the global and static blocks (as gdb.Block objects),
2205 of the underlying symbol table, respectively.
2207 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2208 object associated with a PC value.
2210 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2211 of the address range occupied by code for the current source line.
2213 * Go language support.
2214 GDB now supports debugging programs written in the Go programming
2217 * GDBserver now supports stdio connections.
2218 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2220 * The binary "gdbtui" can no longer be built or installed.
2221 Use "gdb -tui" instead.
2223 * GDB will now print "flag" enums specially. A flag enum is one where
2224 all the enumerator values have no bits in common when pairwise
2225 "and"ed. When printing a value whose type is a flag enum, GDB will
2226 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2227 (gdb) print (enum E) 3
2230 * The filename part of a linespec will now match trailing components
2231 of a source file name. For example, "break gcc/expr.c:1000" will
2232 now set a breakpoint in build/gcc/expr.c, but not
2233 build/libcpp/expr.c.
2235 * The "info proc" and "generate-core-file" commands will now also
2236 work on remote targets connected to GDBserver on Linux.
2238 * The command "info catch" has been removed. It has been disabled
2239 since December 2007.
2241 * The "catch exception" and "catch assert" commands now accept
2242 a condition at the end of the command, much like the "break"
2243 command does. For instance:
2245 (gdb) catch exception Constraint_Error if Barrier = True
2247 Previously, it was possible to add a condition to such catchpoints,
2248 but it had to be done as a second step, after the catchpoint had been
2249 created, using the "condition" command.
2251 * The "info static-tracepoint-marker" command will now also work on
2252 native Linux targets with in-process agent.
2254 * GDB can now set breakpoints on inlined functions.
2256 * The .gdb_index section has been updated to include symbols for
2257 inlined functions. GDB will ignore older .gdb_index sections by
2258 default, which could cause symbol files to be loaded more slowly
2259 until their .gdb_index sections can be recreated. The new command
2260 "set use-deprecated-index-sections on" will cause GDB to use any older
2261 .gdb_index sections it finds. This will restore performance, but the
2262 ability to set breakpoints on inlined functions will be lost in symbol
2263 files with older .gdb_index sections.
2265 The .gdb_index section has also been updated to record more information
2266 about each symbol. This speeds up the "info variables", "info functions"
2267 and "info types" commands when used with programs having the .gdb_index
2268 section, as well as speeding up debugging with shared libraries using
2269 the .gdb_index section.
2271 * Ada support for GDB/MI Variable Objects has been added.
2273 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2278 ** New command -info-os is the MI equivalent of "info os".
2280 ** Output logs ("set logging" and related) now include MI output.
2284 ** "set use-deprecated-index-sections on|off"
2285 "show use-deprecated-index-sections on|off"
2286 Controls the use of deprecated .gdb_index sections.
2288 ** "catch load" and "catch unload" can be used to stop when a shared
2289 library is loaded or unloaded, respectively.
2291 ** "enable count" can be used to auto-disable a breakpoint after
2294 ** "info vtbl" can be used to show the virtual method tables for
2295 C++ and Java objects.
2297 ** "explore" and its sub commands "explore value" and "explore type"
2298 can be used to recursively explore values and types of
2299 expressions. These commands are available only if GDB is
2300 configured with '--with-python'.
2302 ** "info auto-load" shows status of all kinds of auto-loaded files,
2303 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2304 sequences of commands files, "info auto-load python-scripts"
2305 shows status of auto-loading Python script files,
2306 "info auto-load local-gdbinit" shows status of loading init file
2307 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2308 status of inferior specific thread debugging shared library loading.
2310 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2311 and "show auto-load-scripts" commands have been deprecated, use their
2312 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2313 and "show auto-load python-scripts" counterparts instead.
2315 ** "dprintf location,format,args..." creates a dynamic printf, which
2316 is basically a breakpoint that does a printf and immediately
2317 resumes your program's execution, so it is like a printf that you
2318 can insert dynamically at runtime instead of at compiletime.
2320 ** "set print symbol"
2322 Controls whether GDB attempts to display the symbol, if any,
2323 corresponding to addresses it prints. This defaults to "on", but
2324 you can set it to "off" to restore GDB's previous behavior.
2326 * Deprecated commands
2328 ** For the Renesas Super-H architecture, the "regs" command has been
2329 deprecated, and "info all-registers" should be used instead.
2333 Renesas RL78 rl78-*-elf
2334 HP OpenVMS ia64 ia64-hp-openvms*
2336 * GDBserver supports evaluation of breakpoint conditions. When
2337 support is advertised by GDBserver, GDB may be told to send the
2338 breakpoint conditions in bytecode form to GDBserver. GDBserver
2339 will only report the breakpoint trigger to GDB when its condition
2344 set mips compression
2345 show mips compression
2346 Select the compressed ISA encoding used in functions that have no symbol
2347 information available. The encoding can be set to either of:
2350 and is updated automatically from ELF file flags if available.
2352 set breakpoint condition-evaluation
2353 show breakpoint condition-evaluation
2354 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2355 GDBserver ("target"). Default option "auto" chooses the most efficient
2357 This option can improve debugger efficiency depending on the speed of the
2361 Disable auto-loading globally.
2364 Show auto-loading setting of all kinds of auto-loaded files.
2366 set auto-load gdb-scripts on|off
2367 show auto-load gdb-scripts
2368 Control auto-loading of GDB canned sequences of commands files.
2370 set auto-load python-scripts on|off
2371 show auto-load python-scripts
2372 Control auto-loading of Python script files.
2374 set auto-load local-gdbinit on|off
2375 show auto-load local-gdbinit
2376 Control loading of init file (.gdbinit) from current directory.
2378 set auto-load libthread-db on|off
2379 show auto-load libthread-db
2380 Control auto-loading of inferior specific thread debugging shared library.
2382 set auto-load scripts-directory <dir1>[:<dir2>...]
2383 show auto-load scripts-directory
2384 Set a list of directories from which to load auto-loaded scripts.
2385 Automatically loaded Python scripts and GDB scripts are located in one
2386 of the directories listed by this option.
2387 The delimiter (':' above) may differ according to the host platform.
2389 set auto-load safe-path <dir1>[:<dir2>...]
2390 show auto-load safe-path
2391 Set a list of directories from which it is safe to auto-load files.
2392 The delimiter (':' above) may differ according to the host platform.
2394 set debug auto-load on|off
2395 show debug auto-load
2396 Control display of debugging info for auto-loading the files above.
2398 set dprintf-style gdb|call|agent
2400 Control the way in which a dynamic printf is performed; "gdb"
2401 requests a GDB printf command, while "call" causes dprintf to call a
2402 function in the inferior. "agent" requests that the target agent
2403 (such as GDBserver) do the printing.
2405 set dprintf-function <expr>
2406 show dprintf-function
2407 set dprintf-channel <expr>
2408 show dprintf-channel
2409 Set the function and optional first argument to the call when using
2410 the "call" style of dynamic printf.
2412 set disconnected-dprintf on|off
2413 show disconnected-dprintf
2414 Control whether agent-style dynamic printfs continue to be in effect
2415 after GDB disconnects.
2417 * New configure options
2419 --with-auto-load-dir
2420 Configure default value for the 'set auto-load scripts-directory'
2421 setting above. It defaults to '$debugdir:$datadir/auto-load',
2422 $debugdir representing global debugging info directories (available
2423 via 'show debug-file-directory') and $datadir representing GDB's data
2424 directory (available via 'show data-directory').
2426 --with-auto-load-safe-path
2427 Configure default value for the 'set auto-load safe-path' setting
2428 above. It defaults to the --with-auto-load-dir setting.
2430 --without-auto-load-safe-path
2431 Set 'set auto-load safe-path' to '/', effectively disabling this
2434 * New remote packets
2436 z0/z1 conditional breakpoints extension
2438 The z0/z1 breakpoint insertion packets have been extended to carry
2439 a list of conditional expressions over to the remote stub depending on the
2440 condition evaluation mode. The use of this extension can be controlled
2441 via the "set remote conditional-breakpoints-packet" command.
2445 Specify the signals which the remote stub may pass to the debugged
2446 program without GDB involvement.
2448 * New command line options
2450 --init-command=FILE, -ix Like --command, -x but execute it
2451 before loading inferior.
2452 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2453 execute it before loading inferior.
2455 *** Changes in GDB 7.4
2457 * GDB now handles ambiguous linespecs more consistently; the existing
2458 FILE:LINE support has been expanded to other types of linespecs. A
2459 breakpoint will now be set on all matching locations in all
2460 inferiors, and locations will be added or removed according to
2463 * GDB now allows you to skip uninteresting functions and files when
2464 stepping with the "skip function" and "skip file" commands.
2466 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2467 and "show remote hardware-watchpoint-length-limit". These allows to
2468 set or show the maximum length limit (in bytes) of a remote
2469 target hardware watchpoint.
2471 This allows e.g. to use "unlimited" hardware watchpoints with the
2472 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2473 watchpoints are slower than real hardware watchpoints but are
2474 significantly faster than gdb software watchpoints.
2478 ** The register_pretty_printer function in module gdb.printing now takes
2479 an optional `replace' argument. If True, the new printer replaces any
2482 ** The "maint set python print-stack on|off" command has been
2483 deprecated and will be deleted in GDB 7.5.
2484 A new command: "set python print-stack none|full|message" has
2485 replaced it. Additionally, the default for "print-stack" is
2486 now "message", which just prints the error message without
2489 ** A prompt substitution hook (prompt_hook) is now available to the
2492 ** A new Python module, gdb.prompt has been added to the GDB Python
2493 modules library. This module provides functionality for
2494 escape sequences in prompts (used by set/show
2495 extended-prompt). These escape sequences are replaced by their
2496 corresponding value.
2498 ** Python commands and convenience-functions located in
2499 'data-directory'/python/gdb/command and
2500 'data-directory'/python/gdb/function are now automatically loaded
2503 ** Blocks now provide four new attributes. global_block and
2504 static_block will return the global and static blocks
2505 respectively. is_static and is_global are boolean attributes
2506 that indicate if the block is one of those two types.
2508 ** Symbols now provide the "type" attribute, the type of the symbol.
2510 ** The "gdb.breakpoint" function has been deprecated in favor of
2513 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2514 of a function. This class is based on the "finish" command
2515 available in the CLI.
2517 ** Type objects for struct and union types now allow access to
2518 the fields using standard Python dictionary (mapping) methods.
2519 For example, "some_type['myfield']" now works, as does
2520 "some_type.items()".
2522 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2525 ** A new function, "deep_items" has been added to the gdb.types
2526 module in the GDB Python modules library. This function returns
2527 an iterator over the fields of a struct or union type. Unlike
2528 the standard Python "iteritems" method, it will recursively traverse
2529 any anonymous fields.
2533 ** "*stopped" events can report several new "reason"s, such as
2536 ** Breakpoint changes are now notified using new async records, like
2537 "=breakpoint-modified".
2539 ** New command -ada-task-info.
2541 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2542 $sdir specifies the default system locations of shared libraries.
2543 $pdir specifies the directory where the libpthread used by the application
2546 GDB no longer looks in $sdir and $pdir after it has searched the directories
2547 mentioned in libthread-db-search-path. If you want to search those
2548 directories, they must be specified in libthread-db-search-path.
2549 The default value of libthread-db-search-path on GNU/Linux and Solaris
2550 systems is now "$sdir:$pdir".
2552 $pdir is not supported by gdbserver, it is currently ignored.
2553 $sdir is supported by gdbserver.
2555 * New configure option --with-iconv-bin.
2556 When using the internationalization support like the one in the GNU C
2557 library, GDB will invoke the "iconv" program to get a list of supported
2558 character sets. If this program lives in a non-standard location, one can
2559 use this option to specify where to find it.
2561 * When natively debugging programs on PowerPC BookE processors running
2562 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2563 watchpoints, which specify a mask in addition to an address to watch.
2564 The mask specifies that some bits of an address (the bits which are
2565 reset in the mask) should be ignored when matching the address accessed
2566 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2567 section in the user manual for more details.
2569 * The new option --once causes GDBserver to stop listening for connections once
2570 the first connection is made. The listening port used by GDBserver will
2571 become available after that.
2573 * New commands "info macros" and "alias" have been added.
2575 * New function parameters suffix @entry specifies value of function parameter
2576 at the time the function got called. Entry values are available only since
2582 "!" is now an alias of the "shell" command.
2583 Note that no space is needed between "!" and SHELL COMMAND.
2587 watch EXPRESSION mask MASK_VALUE
2588 The watch command now supports the mask argument which allows creation
2589 of masked watchpoints, if the current architecture supports this feature.
2591 info auto-load-scripts [REGEXP]
2592 This command was formerly named "maintenance print section-scripts".
2593 It is now generally useful and is no longer a maintenance-only command.
2595 info macro [-all] [--] MACRO
2596 The info macro command has new options `-all' and `--'. The first for
2597 printing all definitions of a macro. The second for explicitly specifying
2598 the end of arguments and the beginning of the macro name in case the macro
2599 name starts with a hyphen.
2601 collect[/s] EXPRESSIONS
2602 The tracepoint collect command now takes an optional modifier "/s"
2603 that directs it to dereference pointer-to-character types and
2604 collect the bytes of memory up to a zero byte. The behavior is
2605 similar to what you see when you use the regular print command on a
2606 string. An optional integer following the "/s" sets a bound on the
2607 number of bytes that will be collected.
2610 The trace start command now interprets any supplied arguments as a
2611 note to be recorded with the trace run, with an effect similar to
2612 setting the variable trace-notes.
2615 The trace stop command now interprets any arguments as a note to be
2616 mentioned along with the tstatus report that the trace was stopped
2617 with a command. The effect is similar to setting the variable
2620 * Tracepoints can now be enabled and disabled at any time after a trace
2621 experiment has been started using the standard "enable" and "disable"
2622 commands. It is now possible to start a trace experiment with no enabled
2623 tracepoints; GDB will display a warning, but will allow the experiment to
2624 begin, assuming that tracepoints will be enabled as needed while the trace
2627 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2628 locations with 4-byte instructions, when they were previously
2629 limited to locations with instructions of 5 bytes or longer.
2633 set debug dwarf2-read
2634 show debug dwarf2-read
2635 Turns on or off display of debugging messages related to reading
2636 DWARF debug info. The default is off.
2638 set debug symtab-create
2639 show debug symtab-create
2640 Turns on or off display of debugging messages related to symbol table
2641 creation. The default is off.
2644 show extended-prompt
2645 Set the GDB prompt, and allow escape sequences to be inserted to
2646 display miscellaneous information (see 'help set extended-prompt'
2647 for the list of sequences). This prompt (and any information
2648 accessed through the escape sequences) is updated every time the
2649 prompt is displayed.
2651 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2652 show print entry-values
2653 Set printing of frame argument values at function entry. In some cases
2654 GDB can determine the value of function argument which was passed by the
2655 function caller, even if the value was modified inside the called function.
2657 set debug entry-values
2658 show debug entry-values
2659 Control display of debugging info for determining frame argument values at
2660 function entry and virtual tail call frames.
2662 set basenames-may-differ
2663 show basenames-may-differ
2664 Set whether a source file may have multiple base names.
2665 (A "base name" is the name of a file with the directory part removed.
2666 Example: The base name of "/home/user/hello.c" is "hello.c".)
2667 If set, GDB will canonicalize file names (e.g., expand symlinks)
2668 before comparing them. Canonicalization is an expensive operation,
2669 but it allows the same file be known by more than one base name.
2670 If not set (the default), all source files are assumed to have just
2671 one base name, and gdb will do file name comparisons more efficiently.
2677 Set a user name and notes for the current and any future trace runs.
2678 This is useful for long-running and/or disconnected traces, to
2679 inform others (or yourself) as to who is running the trace, supply
2680 contact information, or otherwise explain what is going on.
2682 set trace-stop-notes
2683 show trace-stop-notes
2684 Set a note attached to the trace run, that is displayed when the
2685 trace has been stopped by a tstop command. This is useful for
2686 instance as an explanation, if you are stopping a trace run that was
2687 started by someone else.
2689 * New remote packets
2693 Dynamically enable a tracepoint in a started trace experiment.
2697 Dynamically disable a tracepoint in a started trace experiment.
2701 Set the user and notes of the trace run.
2705 Query the current status of a tracepoint.
2709 Query the minimum length of instruction at which a fast tracepoint may
2712 * Dcache size (number of lines) and line-size are now runtime-configurable
2713 via "set dcache line" and "set dcache line-size" commands.
2717 Texas Instruments TMS320C6x tic6x-*-*
2721 Renesas RL78 rl78-*-elf
2723 *** Changes in GDB 7.3.1
2725 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2727 *** Changes in GDB 7.3
2729 * GDB has a new command: "thread find [REGEXP]".
2730 It finds the thread id whose name, target id, or thread extra info
2731 matches the given regular expression.
2733 * The "catch syscall" command now works on mips*-linux* targets.
2735 * The -data-disassemble MI command now supports modes 2 and 3 for
2736 dumping the instruction opcodes.
2738 * New command line options
2740 -data-directory DIR Specify DIR as the "data-directory".
2741 This is mostly for testing purposes.
2743 * The "maint set python auto-load on|off" command has been renamed to
2744 "set auto-load-scripts on|off".
2746 * GDB has a new command: "set directories".
2747 It is like the "dir" command except that it replaces the
2748 source path list instead of augmenting it.
2750 * GDB now understands thread names.
2752 On GNU/Linux, "info threads" will display the thread name as set by
2753 prctl or pthread_setname_np.
2755 There is also a new command, "thread name", which can be used to
2756 assign a name internally for GDB to display.
2759 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2760 has been integrated into GDB.
2764 ** The function gdb.Write now accepts an optional keyword 'stream'.
2765 This keyword, when provided, will direct the output to either
2766 stdout, stderr, or GDB's logging output.
2768 ** Parameters can now be be sub-classed in Python, and in particular
2769 you may implement the get_set_doc and get_show_doc functions.
2770 This improves how Parameter set/show documentation is processed
2771 and allows for more dynamic content.
2773 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2774 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2775 have an is_valid method.
2777 ** Breakpoints can now be sub-classed in Python, and in particular
2778 you may implement a 'stop' function that is executed each time
2779 the inferior reaches that breakpoint.
2781 ** New function gdb.lookup_global_symbol looks up a global symbol.
2783 ** GDB values in Python are now callable if the value represents a
2784 function. For example, if 'some_value' represents a function that
2785 takes two integer parameters and returns a value, you can call
2786 that function like so:
2788 result = some_value (10,20)
2790 ** Module gdb.types has been added.
2791 It contains a collection of utilities for working with gdb.Types objects:
2792 get_basic_type, has_field, make_enum_dict.
2794 ** Module gdb.printing has been added.
2795 It contains utilities for writing and registering pretty-printers.
2796 New classes: PrettyPrinter, SubPrettyPrinter,
2797 RegexpCollectionPrettyPrinter.
2798 New function: register_pretty_printer.
2800 ** New commands "info pretty-printers", "enable pretty-printer" and
2801 "disable pretty-printer" have been added.
2803 ** gdb.parameter("directories") is now available.
2805 ** New function gdb.newest_frame returns the newest frame in the
2808 ** The gdb.InferiorThread class has a new "name" attribute. This
2809 holds the thread's name.
2811 ** Python Support for Inferior events.
2812 Python scripts can add observers to be notified of events
2813 occurring in the process being debugged.
2814 The following events are currently supported:
2815 - gdb.events.cont Continue event.
2816 - gdb.events.exited Inferior exited event.
2817 - gdb.events.stop Signal received, and Breakpoint hit events.
2821 ** GDB now puts template parameters in scope when debugging in an
2822 instantiation. For example, if you have:
2824 template<int X> int func (void) { return X; }
2826 then if you step into func<5>, "print X" will show "5". This
2827 feature requires proper debuginfo support from the compiler; it
2828 was added to GCC 4.5.
2830 ** The motion commands "next", "finish", "until", and "advance" now
2831 work better when exceptions are thrown. In particular, GDB will
2832 no longer lose control of the inferior; instead, the GDB will
2833 stop the inferior at the point at which the exception is caught.
2834 This functionality requires a change in the exception handling
2835 code that was introduced in GCC 4.5.
2837 * GDB now follows GCC's rules on accessing volatile objects when
2838 reading or writing target state during expression evaluation.
2839 One notable difference to prior behavior is that "print x = 0"
2840 no longer generates a read of x; the value of the assignment is
2841 now always taken directly from the value being assigned.
2843 * GDB now has some support for using labels in the program's source in
2844 linespecs. For instance, you can use "advance label" to continue
2845 execution to a label.
2847 * GDB now has support for reading and writing a new .gdb_index
2848 section. This section holds a fast index of DWARF debugging
2849 information and can be used to greatly speed up GDB startup and
2850 operation. See the documentation for `save gdb-index' for details.
2852 * The "watch" command now accepts an optional "-location" argument.
2853 When used, this causes GDB to watch the memory referred to by the
2854 expression. Such a watchpoint is never deleted due to it going out
2857 * GDB now supports thread debugging of core dumps on GNU/Linux.
2859 GDB now activates thread debugging using the libthread_db library
2860 when debugging GNU/Linux core dumps, similarly to when debugging
2861 live processes. As a result, when debugging a core dump file, GDB
2862 is now able to display pthread_t ids of threads. For example, "info
2863 threads" shows the same output as when debugging the process when it
2864 was live. In earlier releases, you'd see something like this:
2867 * 1 LWP 6780 main () at main.c:10
2869 While now you see this:
2872 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2874 It is also now possible to inspect TLS variables when debugging core
2877 When debugging a core dump generated on a machine other than the one
2878 used to run GDB, you may need to point GDB at the correct
2879 libthread_db library with the "set libthread-db-search-path"
2880 command. See the user manual for more details on this command.
2882 * When natively debugging programs on PowerPC BookE processors running
2883 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2884 which stop execution of the inferior whenever it executes an instruction
2885 at any address within the specified range. See the "PowerPC Embedded"
2886 section in the user manual for more details.
2888 * New features in the GDB remote stub, GDBserver
2890 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2891 and i686 LynxOS (version 5.x).
2893 ** GDBserver is now supported on Blackfin Linux.
2895 * New native configurations
2897 ia64 HP-UX ia64-*-hpux*
2901 Analog Devices, Inc. Blackfin Processor bfin-*
2903 * Ada task switching is now supported on sparc-elf targets when
2904 debugging a program using the Ravenscar Profile. For more information,
2905 see the "Tasking Support when using the Ravenscar Profile" section
2906 in the GDB user manual.
2908 * Guile support was removed.
2910 * New features in the GNU simulator
2912 ** The --map-info flag lists all known core mappings.
2914 ** CFI flashes may be simulated via the "cfi" device.
2916 *** Changes in GDB 7.2
2918 * Shared library support for remote targets by default
2920 When GDB is configured for a generic, non-OS specific target, like
2921 for example, --target=arm-eabi or one of the many *-*-elf targets,
2922 GDB now queries remote stubs for loaded shared libraries using the
2923 `qXfer:libraries:read' packet. Previously, shared library support
2924 was always disabled for such configurations.
2928 ** Argument Dependent Lookup (ADL)
2930 In C++ ADL lookup directs function search to the namespaces of its
2931 arguments even if the namespace has not been imported.
2941 Here the compiler will search for `foo' in the namespace of 'b'
2942 and find A::foo. GDB now supports this. This construct is commonly
2943 used in the Standard Template Library for operators.
2945 ** Improved User Defined Operator Support
2947 In addition to member operators, GDB now supports lookup of operators
2948 defined in a namespace and imported with a `using' directive, operators
2949 defined in the global scope, operators imported implicitly from an
2950 anonymous namespace, and the ADL operators mentioned in the previous
2952 GDB now also supports proper overload resolution for all the previously
2953 mentioned flavors of operators.
2955 ** static const class members
2957 Printing of static const class members that are initialized in the
2958 class definition has been fixed.
2960 * Windows Thread Information Block access.
2962 On Windows targets, GDB now supports displaying the Windows Thread
2963 Information Block (TIB) structure. This structure is visible either
2964 by using the new command `info w32 thread-information-block' or, by
2965 dereferencing the new convenience variable named `$_tlb', a
2966 thread-specific pointer to the TIB. This feature is also supported
2967 when remote debugging using GDBserver.
2969 * Static tracepoints
2971 Static tracepoints are calls in the user program into a tracing
2972 library. One such library is a port of the LTTng kernel tracer to
2973 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2974 When debugging with GDBserver, GDB now supports combining the GDB
2975 tracepoint machinery with such libraries. For example: the user can
2976 use GDB to probe a static tracepoint marker (a call from the user
2977 program into the tracing library) with the new "strace" command (see
2978 "New commands" below). This creates a "static tracepoint" in the
2979 breakpoint list, that can be manipulated with the same feature set
2980 as fast and regular tracepoints. E.g., collect registers, local and
2981 global variables, collect trace state variables, and define
2982 tracepoint conditions. In addition, the user can collect extra
2983 static tracepoint marker specific data, by collecting the new
2984 $_sdata internal variable. When analyzing the trace buffer, you can
2985 inspect $_sdata like any other variable available to GDB. For more
2986 information, see the "Tracepoints" chapter in GDB user manual. New
2987 remote packets have been defined to support static tracepoints, see
2988 the "New remote packets" section below.
2990 * Better reconstruction of tracepoints after disconnected tracing
2992 GDB will attempt to download the original source form of tracepoint
2993 definitions when starting a trace run, and then will upload these
2994 upon reconnection to the target, resulting in a more accurate
2995 reconstruction of the tracepoints that are in use on the target.
2999 You can now exercise direct control over the ways that GDB can
3000 affect your program. For instance, you can disallow the setting of
3001 breakpoints, so that the program can run continuously (assuming
3002 non-stop mode). In addition, the "observer" variable is available
3003 to switch all of the different controls; in observer mode, GDB
3004 cannot affect the target's behavior at all, which is useful for
3005 tasks like diagnosing live systems in the field.
3007 * The new convenience variable $_thread holds the number of the
3010 * New remote packets
3014 Return the address of the Windows Thread Information Block of a given thread.
3018 In response to several of the tracepoint packets, the target may now
3019 also respond with a number of intermediate `qRelocInsn' request
3020 packets before the final result packet, to have GDB handle
3021 relocating an instruction to execute at a different address. This
3022 is particularly useful for stubs that support fast tracepoints. GDB
3023 reports support for this feature in the qSupported packet.
3027 List static tracepoint markers in the target program.
3031 List static tracepoint markers at a given address in the target
3034 qXfer:statictrace:read
3036 Read the static trace data collected (by a `collect $_sdata'
3037 tracepoint action). The remote stub reports support for this packet
3038 to gdb's qSupported query.
3042 Send the current settings of GDB's permission flags.
3046 Send part of the source (textual) form of a tracepoint definition,
3047 which includes location, conditional, and action list.
3049 * The source command now accepts a -s option to force searching for the
3050 script in the source search path even if the script name specifies
3053 * New features in the GDB remote stub, GDBserver
3055 - GDBserver now support tracepoints (including fast tracepoints, and
3056 static tracepoints). The feature is currently supported by the
3057 i386-linux and amd64-linux builds. See the "Tracepoints support
3058 in gdbserver" section in the manual for more information.
3060 GDBserver JIT compiles the tracepoint's conditional agent
3061 expression bytecode into native code whenever possible for low
3062 overhead dynamic tracepoints conditionals. For such tracepoints,
3063 an expression that examines program state is evaluated when the
3064 tracepoint is reached, in order to determine whether to capture
3065 trace data. If the condition is simple and false, processing the
3066 tracepoint finishes very quickly and no data is gathered.
3068 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3069 for static tracepoints support.
3071 - GDBserver now supports x86_64 Windows 64-bit debugging.
3073 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3074 it understands register description.
3076 * The --batch flag now disables pagination and queries.
3078 * X86 general purpose registers
3080 GDB now supports reading/writing byte, word and double-word x86
3081 general purpose registers directly. This means you can use, say,
3082 $ah or $ax to refer, respectively, to the byte register AH and
3083 16-bit word register AX that are actually portions of the 32-bit
3084 register EAX or 64-bit register RAX.
3086 * The `commands' command now accepts a range of breakpoints to modify.
3087 A plain `commands' following a command that creates multiple
3088 breakpoints affects all the breakpoints set by that command. This
3089 applies to breakpoints set by `rbreak', and also applies when a
3090 single `break' command creates multiple breakpoints (e.g.,
3091 breakpoints on overloaded c++ functions).
3093 * The `rbreak' command now accepts a filename specification as part of
3094 its argument, limiting the functions selected by the regex to those
3095 in the specified file.
3097 * Support for remote debugging Windows and SymbianOS shared libraries
3098 from Unix hosts has been improved. Non Windows GDB builds now can
3099 understand target reported file names that follow MS-DOS based file
3100 system semantics, such as file names that include drive letters and
3101 use the backslash character as directory separator. This makes it
3102 possible to transparently use the "set sysroot" and "set
3103 solib-search-path" on Unix hosts to point as host copies of the
3104 target's shared libraries. See the new command "set
3105 target-file-system-kind" described below, and the "Commands to
3106 specify files" section in the user manual for more information.
3110 eval template, expressions...
3111 Convert the values of one or more expressions under the control
3112 of the string template to a command line, and call it.
3114 set target-file-system-kind unix|dos-based|auto
3115 show target-file-system-kind
3116 Set or show the assumed file system kind for target reported file
3119 save breakpoints <filename>
3120 Save all current breakpoint definitions to a file suitable for use
3121 in a later debugging session. To read the saved breakpoint
3122 definitions, use the `source' command.
3124 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3127 info static-tracepoint-markers
3128 Display information about static tracepoint markers in the target.
3130 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3131 Define a static tracepoint by probing a marker at the given
3132 function, line, address, or marker ID.
3136 Enable and disable observer mode.
3138 set may-write-registers on|off
3139 set may-write-memory on|off
3140 set may-insert-breakpoints on|off
3141 set may-insert-tracepoints on|off
3142 set may-insert-fast-tracepoints on|off
3143 set may-interrupt on|off
3144 Set individual permissions for GDB effects on the target. Note that
3145 some of these settings can have undesirable or surprising
3146 consequences, particularly when changed in the middle of a session.
3147 For instance, disabling the writing of memory can prevent
3148 breakpoints from being inserted, cause single-stepping to fail, or
3149 even crash your program, if you disable after breakpoints have been
3150 inserted. However, GDB should not crash.
3152 set record memory-query on|off
3153 show record memory-query
3154 Control whether to stop the inferior if memory changes caused
3155 by an instruction cannot be recorded.
3160 The disassemble command now supports "start,+length" form of two arguments.
3164 ** GDB now provides a new directory location, called the python directory,
3165 where Python scripts written for GDB can be installed. The location
3166 of that directory is <data-directory>/python, where <data-directory>
3167 is the GDB data directory. For more details, see section `Scripting
3168 GDB using Python' in the manual.
3170 ** The GDB Python API now has access to breakpoints, symbols, symbol
3171 tables, program spaces, inferiors, threads and frame's code blocks.
3172 Additionally, GDB Parameters can now be created from the API, and
3173 manipulated via set/show in the CLI.
3175 ** New functions gdb.target_charset, gdb.target_wide_charset,
3176 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3178 ** New exception gdb.GdbError.
3180 ** Pretty-printers are now also looked up in the current program space.
3182 ** Pretty-printers can now be individually enabled and disabled.
3184 ** GDB now looks for names of Python scripts to auto-load in a
3185 special section named `.debug_gdb_scripts', in addition to looking
3186 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3188 * Tracepoint actions were unified with breakpoint commands. In particular,
3189 there are no longer differences in "info break" output for breakpoints and
3190 tracepoints and the "commands" command can be used for both tracepoints and
3191 regular breakpoints.
3195 ARM Symbian arm*-*-symbianelf*
3197 * D language support.
3198 GDB now supports debugging programs written in the D programming
3201 * GDB now supports the extended ptrace interface for PowerPC which is
3202 available since Linux kernel version 2.6.34. This automatically enables
3203 any hardware breakpoints and additional hardware watchpoints available in
3204 the processor. The old ptrace interface exposes just one hardware
3205 watchpoint and no hardware breakpoints.
3207 * GDB is now able to use the Data Value Compare (DVC) register available on
3208 embedded PowerPC processors to implement in hardware simple watchpoint
3209 conditions of the form:
3211 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3213 This works in native GDB running on Linux kernels with the extended ptrace
3214 interface mentioned above.
3216 *** Changes in GDB 7.1
3220 ** Namespace Support
3222 GDB now supports importing of namespaces in C++. This enables the
3223 user to inspect variables from imported namespaces. Support for
3224 namepace aliasing has also been added. So, if a namespace is
3225 aliased in the current scope (e.g. namepace C=A; ) the user can
3226 print variables using the alias (e.g. (gdb) print C::x).
3230 All known bugs relating to the printing of virtual base class were
3231 fixed. It is now possible to call overloaded static methods using a
3236 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3237 and reinterpret_cast<> are now handled by the C++ expression parser.
3241 Xilinx MicroBlaze microblaze-*-*
3246 Xilinx MicroBlaze microblaze
3249 * Multi-program debugging.
3251 GDB now has support for multi-program (a.k.a. multi-executable or
3252 multi-exec) debugging. This allows for debugging multiple inferiors
3253 simultaneously each running a different program under the same GDB
3254 session. See "Debugging Multiple Inferiors and Programs" in the
3255 manual for more information. This implied some user visible changes
3256 in the multi-inferior support. For example, "info inferiors" now
3257 lists inferiors that are not running yet or that have exited
3258 already. See also "New commands" and "New options" below.
3260 * New tracing features
3262 GDB's tracepoint facility now includes several new features:
3264 ** Trace state variables
3266 GDB tracepoints now include support for trace state variables, which
3267 are variables managed by the target agent during a tracing
3268 experiment. They are useful for tracepoints that trigger each
3269 other, so for instance one tracepoint can count hits in a variable,
3270 and then a second tracepoint has a condition that is true when the
3271 count reaches a particular value. Trace state variables share the
3272 $-syntax of GDB convenience variables, and can appear in both
3273 tracepoint actions and condition expressions. Use the "tvariable"
3274 command to create, and "info tvariables" to view; see "Trace State
3275 Variables" in the manual for more detail.
3279 GDB now includes an option for defining fast tracepoints, which
3280 targets may implement more efficiently, such as by installing a jump
3281 into the target agent rather than a trap instruction. The resulting
3282 speedup can be by two orders of magnitude or more, although the
3283 tradeoff is that some program locations on some target architectures
3284 might not allow fast tracepoint installation, for instance if the
3285 instruction to be replaced is shorter than the jump. To request a
3286 fast tracepoint, use the "ftrace" command, with syntax identical to
3287 the regular trace command.
3289 ** Disconnected tracing
3291 It is now possible to detach GDB from the target while it is running
3292 a trace experiment, then reconnect later to see how the experiment
3293 is going. In addition, a new variable disconnected-tracing lets you
3294 tell the target agent whether to continue running a trace if the
3295 connection is lost unexpectedly.
3299 GDB now has the ability to save the trace buffer into a file, and
3300 then use that file as a target, similarly to you can do with
3301 corefiles. You can select trace frames, print data that was
3302 collected in them, and use tstatus to display the state of the
3303 tracing run at the moment that it was saved. To create a trace
3304 file, use "tsave <filename>", and to use it, do "target tfile
3307 ** Circular trace buffer
3309 You can ask the target agent to handle the trace buffer as a
3310 circular buffer, discarding the oldest trace frames to make room for
3311 newer ones, by setting circular-trace-buffer to on. This feature may
3312 not be available for all target agents.
3317 The disassemble command, when invoked with two arguments, now requires
3318 the arguments to be comma-separated.
3321 The info variables command now displays variable definitions. Files
3322 which only declare a variable are not shown.
3325 The source command is now capable of sourcing Python scripts.
3326 This feature is dependent on the debugger being build with Python
3329 Related to this enhancement is also the introduction of a new command
3330 "set script-extension" (see below).
3332 * New commands (for set/show, see "New options" below)
3334 record save [<FILENAME>]
3335 Save a file (in core file format) containing the process record
3336 execution log for replay debugging at a later time.
3338 record restore <FILENAME>
3339 Restore the process record execution log that was saved at an
3340 earlier time, for replay debugging.
3342 add-inferior [-copies <N>] [-exec <FILENAME>]
3345 clone-inferior [-copies <N>] [ID]
3346 Make a new inferior ready to execute the same program another
3347 inferior has loaded.
3352 maint info program-spaces
3353 List the program spaces loaded into GDB.
3355 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3356 show remote interrupt-sequence
3357 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3358 as the sequence to the remote target in order to interrupt the execution.
3359 Ctrl-C is a default. Some system prefers BREAK which is high level of
3360 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3361 Magic SysRq g. It is BREAK signal and character 'g'.
3363 set remote interrupt-on-connect [on | off]
3364 show remote interrupt-on-connect
3365 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3366 remote target when gdb connects to it. This is needed when you debug
3369 set remotebreak [on | off]
3371 Deprecated. Use "set/show remote interrupt-sequence" instead.
3373 tvariable $NAME [ = EXP ]
3374 Create or modify a trace state variable.
3377 List trace state variables and their values.
3379 delete tvariable $NAME ...
3380 Delete one or more trace state variables.
3383 Evaluate the given expressions without collecting anything into the
3384 trace buffer. (Valid in tracepoint actions only.)
3386 ftrace FN / FILE:LINE / *ADDR
3387 Define a fast tracepoint at the given function, line, or address.
3389 * New expression syntax
3391 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3392 GDB now parses 0b101010 identically with 42.
3396 set follow-exec-mode new|same
3397 show follow-exec-mode
3398 Control whether GDB reuses the same inferior across an exec call or
3399 creates a new one. This is useful to be able to restart the old
3400 executable after the inferior having done an exec call.
3402 set default-collect EXPR, ...
3403 show default-collect
3404 Define a list of expressions to be collected at each tracepoint.
3405 This is a useful way to ensure essential items are not overlooked,
3406 such as registers or a critical global variable.
3408 set disconnected-tracing
3409 show disconnected-tracing
3410 If set to 1, the target is instructed to continue tracing if it
3411 loses its connection to GDB. If 0, the target is to stop tracing
3414 set circular-trace-buffer
3415 show circular-trace-buffer
3416 If set to on, the target is instructed to use a circular trace buffer
3417 and discard the oldest trace frames instead of stopping the trace due
3418 to a full trace buffer. If set to off, the trace stops when the buffer
3419 fills up. Some targets may not support this.
3421 set script-extension off|soft|strict
3422 show script-extension
3423 If set to "off", the debugger does not perform any script language
3424 recognition, and all sourced files are assumed to be GDB scripts.
3425 If set to "soft" (the default), files are sourced according to
3426 filename extension, falling back to GDB scripts if the first
3428 If set to "strict", files are sourced according to filename extension.
3430 set ada trust-PAD-over-XVS on|off
3431 show ada trust-PAD-over-XVS
3432 If off, activate a workaround against a bug in the debugging information
3433 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3434 the GCC sources for more information about the GNAT encoding and
3435 PAD types in particular). It is always safe to set this option to
3436 off, but this introduces a slight performance penalty. The default
3439 * Python API Improvements
3441 ** GDB provides the new class gdb.LazyString. This is useful in
3442 some pretty-printing cases. The new method gdb.Value.lazy_string
3443 provides a simple way to create objects of this type.
3445 ** The fields returned by gdb.Type.fields now have an
3446 `is_base_class' attribute.
3448 ** The new method gdb.Type.range returns the range of an array type.
3450 ** The new method gdb.parse_and_eval can be used to parse and
3451 evaluate an expression.
3453 * New remote packets
3456 Define a trace state variable.
3459 Get the current value of a trace state variable.
3462 Set desired tracing behavior upon disconnection.
3465 Set the trace buffer to be linear or circular.
3468 Get data about the tracepoints currently in use.
3472 Process record now works correctly with hardware watchpoints.
3474 Multiple bug fixes have been made to the mips-irix port, making it
3475 much more reliable. In particular:
3476 - Debugging threaded applications is now possible again. Previously,
3477 GDB would hang while starting the program, or while waiting for
3478 the program to stop at a breakpoint.
3479 - Attaching to a running process no longer hangs.
3480 - An error occurring while loading a core file has been fixed.
3481 - Changing the value of the PC register now works again. This fixes
3482 problems observed when using the "jump" command, or when calling
3483 a function from GDB, or even when assigning a new value to $pc.
3484 - With the "finish" and "return" commands, the return value for functions
3485 returning a small array is now correctly printed.
3486 - It is now possible to break on shared library code which gets executed
3487 during a shared library init phase (code executed while executing
3488 their .init section). Previously, the breakpoint would have no effect.
3489 - GDB is now able to backtrace through the signal handler for
3490 non-threaded programs.
3492 PIE (Position Independent Executable) programs debugging is now supported.
3493 This includes debugging execution of PIC (Position Independent Code) shared
3494 libraries although for that, it should be possible to run such libraries as an
3497 *** Changes in GDB 7.0
3499 * GDB now has an interface for JIT compilation. Applications that
3500 dynamically generate code can create symbol files in memory and register
3501 them with GDB. For users, the feature should work transparently, and
3502 for JIT developers, the interface is documented in the GDB manual in the
3503 "JIT Compilation Interface" chapter.
3505 * Tracepoints may now be conditional. The syntax is as for
3506 breakpoints; either an "if" clause appended to the "trace" command,
3507 or the "condition" command is available. GDB sends the condition to
3508 the target for evaluation using the same bytecode format as is used
3509 for tracepoint actions.
3511 * The disassemble command now supports: an optional /r modifier, print the
3512 raw instructions in hex as well as in symbolic form, and an optional /m
3513 modifier to print mixed source+assembly.
3515 * Process record and replay
3517 In a architecture environment that supports ``process record and
3518 replay'', ``process record and replay'' target can record a log of
3519 the process execution, and replay it with both forward and reverse
3522 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3523 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3524 set execution-direction {forward|reverse}, for targets that support
3527 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3528 feature is available with a native GDB running on kernel version
3531 * GDB now has support for multi-byte and wide character sets on the
3532 target. Strings whose character type is wchar_t, char16_t, or
3533 char32_t are now correctly printed. GDB supports wide- and unicode-
3534 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3535 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3536 `printf'. This feature requires iconv to work properly; if your
3537 system does not have a working iconv, GDB can use GNU libiconv. See
3538 the installation instructions for more information.
3540 * GDB now supports automatic retrieval of shared library files from
3541 remote targets. To use this feature, specify a system root that begins
3542 with the `remote:' prefix, either via the `set sysroot' command or via
3543 the `--with-sysroot' configure-time option.
3545 * "info sharedlibrary" now takes an optional regex of libraries to show,
3546 and it now reports if a shared library has no debugging information.
3548 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3549 now complete on file names.
3551 * When completing in expressions, gdb will attempt to limit
3552 completions to allowable structure or union fields, where appropriate.
3553 For instance, consider:
3555 # struct example { int f1; double f2; };
3556 # struct example variable;
3559 If the user types TAB at the end of this command line, the available
3560 completions will be "f1" and "f2".
3562 * Inlined functions are now supported. They show up in backtraces, and
3563 the "step", "next", and "finish" commands handle them automatically.
3565 * GDB now supports the token-splicing (##) and stringification (#)
3566 operators when expanding macros. It also supports variable-arity
3569 * GDB now supports inspecting extra signal information, exported by
3570 the new $_siginfo convenience variable. The feature is currently
3571 implemented on linux ARM, i386 and amd64.
3573 * GDB can now display the VFP floating point registers and NEON vector
3574 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3575 can provide these registers (requires Linux 2.6.30 or later). Remote
3576 and simulator targets may also provide them.
3578 * New remote packets
3581 Search memory for a sequence of bytes.
3584 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3585 operation over reliable transport links. Use of this packet is
3586 controlled by the `set remote noack-packet' command.
3589 Kill the process with the specified process ID. Use this in preference
3590 to `k' when multiprocess protocol extensions are supported.
3593 Obtains additional operating system information
3597 Read or write additional signal information.
3599 * Removed remote protocol undocumented extension
3601 An undocumented extension to the remote protocol's `S' stop reply
3602 packet that permited the stub to pass a process id was removed.
3603 Remote servers should use the `T' stop reply packet instead.
3605 * GDB now supports multiple function calling conventions according to the
3606 DWARF-2 DW_AT_calling_convention function attribute.
3608 * The SH target utilizes the aforementioned change to distinguish between gcc
3609 and Renesas calling convention. It also adds the new CLI commands
3610 `set/show sh calling-convention'.
3612 * GDB can now read compressed debug sections, as produced by GNU gold
3613 with the --compress-debug-sections=zlib flag.
3615 * 64-bit core files are now supported on AIX.
3617 * Thread switching is now supported on Tru64.
3619 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3620 which will be allocated using malloc later in program execution.
3622 * The qXfer:libraries:read remote procotol packet now allows passing a
3623 list of section offsets.
3625 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3626 conditions handling signals delivered during attach or thread creation
3627 have also been fixed.
3629 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3630 From the user's standpoint, all unqualified instances of True and False
3631 are treated as the standard definitions, regardless of context.
3633 * GDB now parses C++ symbol and type names more flexibly. For
3636 template<typename T> class C { };
3639 GDB will now correctly handle all of:
3641 ptype C<char const *>
3642 ptype C<char const*>
3643 ptype C<const char *>
3644 ptype C<const char*>
3646 * New features in the GDB remote stub, gdbserver
3648 - The "--wrapper" command-line argument tells gdbserver to use a
3649 wrapper program to launch programs for debugging.
3651 - On PowerPC and S/390 targets, it is now possible to use a single
3652 gdbserver executable to debug both 32-bit and 64-bit programs.
3653 (This requires gdbserver itself to be built as a 64-bit executable.)
3655 - gdbserver uses the new noack protocol mode for TCP connections to
3656 reduce communications latency, if also supported and enabled in GDB.
3658 - Support for the sparc64-linux-gnu target is now included in
3661 - The amd64-linux build of gdbserver now supports debugging both
3662 32-bit and 64-bit programs.
3664 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3665 now support hardware watchpoints, and will use them automatically
3670 GDB now has support for scripting using Python. Whether this is
3671 available is determined at configure time.
3673 New GDB commands can now be written in Python.
3675 * Ada tasking support
3677 Ada tasks can now be inspected in GDB. The following commands have
3681 Print the list of Ada tasks.
3683 Print detailed information about task number N.
3685 Print the task number of the current task.
3687 Switch the context of debugging to task number N.
3689 * Support for user-defined prefixed commands. The "define" command can
3690 add new commands to existing prefixes, e.g. "target".
3692 * Multi-inferior, multi-process debugging.
3694 GDB now has generalized support for multi-inferior debugging. See
3695 "Debugging Multiple Inferiors" in the manual for more information.
3696 Although availability still depends on target support, the command
3697 set is more uniform now. The GNU/Linux specific multi-forks support
3698 has been migrated to this new framework. This implied some user
3699 visible changes; see "New commands" and also "Removed commands"
3702 * Target descriptions can now describe the target OS ABI. See the
3703 "Target Description Format" section in the user manual for more
3706 * Target descriptions can now describe "compatible" architectures
3707 to indicate that the target can execute applications for a different
3708 architecture in addition to those for the main target architecture.
3709 See the "Target Description Format" section in the user manual for
3712 * Multi-architecture debugging.
3714 GDB now includes general supports for debugging applications on
3715 hybrid systems that use more than one single processor architecture
3716 at the same time. Each such hybrid architecture still requires
3717 specific support to be added. The only hybrid architecture supported
3718 in this version of GDB is the Cell Broadband Engine.
3720 * GDB now supports integrated debugging of Cell/B.E. applications that
3721 use both the PPU and SPU architectures. To enable support for hybrid
3722 Cell/B.E. debugging, you need to configure GDB to support both the
3723 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3724 --enable-targets configure option.
3726 * Non-stop mode debugging.
3728 For some targets, GDB now supports an optional mode of operation in
3729 which you can examine stopped threads while other threads continue
3730 to execute freely. This is referred to as non-stop mode, with the
3731 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3732 section in the user manual for more information.
3734 To be able to support remote non-stop debugging, a remote stub needs
3735 to implement the non-stop mode remote protocol extensions, as
3736 described in the "Remote Non-Stop" section of the user manual. The
3737 GDB remote stub, gdbserver, has been adjusted to support these
3738 extensions on linux targets.
3740 * New commands (for set/show, see "New options" below)
3742 catch syscall [NAME(S) | NUMBER(S)]
3743 Catch system calls. Arguments, which should be names of system
3744 calls or their numbers, mean catch only those syscalls. Without
3745 arguments, every syscall will be caught. When the inferior issues
3746 any of the specified syscalls, GDB will stop and announce the system
3747 call, both when it is called and when its call returns. This
3748 feature is currently available with a native GDB running on the
3749 Linux Kernel, under the following architectures: x86, x86_64,
3750 PowerPC and PowerPC64.
3752 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3754 Search memory for a sequence of bytes.
3756 maint set python print-stack
3757 maint show python print-stack
3758 Show a stack trace when an error is encountered in a Python script.
3761 Invoke CODE by passing it to the Python interpreter.
3766 These allow macros to be defined, undefined, and listed
3770 Show operating system information about processes.
3773 List the inferiors currently under GDB's control.
3776 Switch focus to inferior number NUM.
3779 Detach from inferior number NUM.
3782 Kill inferior number NUM.
3786 set spu stop-on-load
3787 show spu stop-on-load
3788 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3790 set spu auto-flush-cache
3791 show spu auto-flush-cache
3792 Control whether to automatically flush the software-managed cache
3793 during Cell/B.E. debugging.
3795 set sh calling-convention
3796 show sh calling-convention
3797 Control the calling convention used when calling SH target functions.
3800 show debug timestamp
3801 Control display of timestamps with GDB debugging output.
3803 set disassemble-next-line
3804 show disassemble-next-line
3805 Control display of disassembled source lines or instructions when
3808 set remote noack-packet
3809 show remote noack-packet
3810 Set/show the use of remote protocol QStartNoAckMode packet. See above
3811 under "New remote packets."
3813 set remote query-attached-packet
3814 show remote query-attached-packet
3815 Control use of remote protocol `qAttached' (query-attached) packet.
3817 set remote read-siginfo-object
3818 show remote read-siginfo-object
3819 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3822 set remote write-siginfo-object
3823 show remote write-siginfo-object
3824 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3827 set remote reverse-continue
3828 show remote reverse-continue
3829 Control use of remote protocol 'bc' (reverse-continue) packet.
3831 set remote reverse-step
3832 show remote reverse-step
3833 Control use of remote protocol 'bs' (reverse-step) packet.
3835 set displaced-stepping
3836 show displaced-stepping
3837 Control displaced stepping mode. Displaced stepping is a way to
3838 single-step over breakpoints without removing them from the debuggee.
3839 Also known as "out-of-line single-stepping".
3842 show debug displaced
3843 Control display of debugging info for displaced stepping.
3845 maint set internal-error
3846 maint show internal-error
3847 Control what GDB does when an internal error is detected.
3849 maint set internal-warning
3850 maint show internal-warning
3851 Control what GDB does when an internal warning is detected.
3856 Use a wrapper program to launch programs for debugging.
3858 set multiple-symbols (all|ask|cancel)
3859 show multiple-symbols
3860 The value of this variable can be changed to adjust the debugger behavior
3861 when an expression or a breakpoint location contains an ambiguous symbol
3862 name (an overloaded function name, for instance).
3864 set breakpoint always-inserted
3865 show breakpoint always-inserted
3866 Keep breakpoints always inserted in the target, as opposed to inserting
3867 them when resuming the target, and removing them when the target stops.
3868 This option can improve debugger performance on slow remote targets.
3870 set arm fallback-mode (arm|thumb|auto)
3871 show arm fallback-mode
3872 set arm force-mode (arm|thumb|auto)
3874 These commands control how ARM GDB determines whether instructions
3875 are ARM or Thumb. The default for both settings is auto, which uses
3876 the current CPSR value for instructions without symbols; previous
3877 versions of GDB behaved as if "set arm fallback-mode arm".
3879 set disable-randomization
3880 show disable-randomization
3881 Standalone programs run with the virtual address space randomization enabled
3882 by default on some platforms. This option keeps the addresses stable across
3883 multiple debugging sessions.
3887 Control whether other threads are stopped or not when some thread hits
3892 Requests that asynchronous execution is enabled in the target, if available.
3893 In this case, it's possible to resume target in the background, and interact
3894 with GDB while the target is running. "show target-async" displays the
3895 current state of asynchronous execution of the target.
3897 set target-wide-charset
3898 show target-wide-charset
3899 The target-wide-charset is the name of the character set that GDB
3900 uses when printing characters whose type is wchar_t.
3902 set tcp auto-retry (on|off)
3904 set tcp connect-timeout
3905 show tcp connect-timeout
3906 These commands allow GDB to retry failed TCP connections to a remote stub
3907 with a specified timeout period; this is useful if the stub is launched
3908 in parallel with GDB but may not be ready to accept connections immediately.
3910 set libthread-db-search-path
3911 show libthread-db-search-path
3912 Control list of directories which GDB will search for appropriate
3915 set schedule-multiple (on|off)
3916 show schedule-multiple
3917 Allow GDB to resume all threads of all processes or only threads of
3918 the current process.
3922 Use more aggressive caching for accesses to the stack. This improves
3923 performance of remote debugging (particularly backtraces) without
3924 affecting correctness.
3926 set interactive-mode (on|off|auto)
3927 show interactive-mode
3928 Control whether GDB runs in interactive mode (on) or not (off).
3929 When in interactive mode, GDB waits for the user to answer all
3930 queries. Otherwise, GDB does not wait and assumes the default
3931 answer. When set to auto (the default), GDB determines which
3932 mode to use based on the stdin settings.
3937 For program forks, this is replaced by the new more generic `info
3938 inferiors' command. To list checkpoints, you can still use the
3939 `info checkpoints' command, which was an alias for the `info forks'
3943 Replaced by the new `inferior' command. To switch between
3944 checkpoints, you can still use the `restart' command, which was an
3945 alias for the `fork' command.
3948 This is removed, since some targets don't have a notion of
3949 processes. To switch between processes, you can still use the
3950 `inferior' command using GDB's own inferior number.
3953 For program forks, this is replaced by the new more generic `kill
3954 inferior' command. To delete a checkpoint, you can still use the
3955 `delete checkpoint' command, which was an alias for the `delete
3959 For program forks, this is replaced by the new more generic `detach
3960 inferior' command. To detach a checkpoint, you can still use the
3961 `detach checkpoint' command, which was an alias for the `detach
3964 * New native configurations
3966 x86/x86_64 Darwin i[34567]86-*-darwin*
3968 x86_64 MinGW x86_64-*-mingw*
3972 Lattice Mico32 lm32-*
3973 x86 DICOS i[34567]86-*-dicos*
3974 x86_64 DICOS x86_64-*-dicos*
3977 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3978 (mingw32ce) debugging.
3984 These commands were actually not implemented on any target.
3986 *** Changes in GDB 6.8
3988 * New native configurations
3990 NetBSD/hppa hppa*-*netbsd*
3991 Xtensa GNU/Linux xtensa*-*-linux*
3995 NetBSD/hppa hppa*-*-netbsd*
3996 Xtensa GNU/Lunux xtensa*-*-linux*
3998 * Change in command line behavior -- corefiles vs. process ids.
4000 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4001 attaching to process NUMBER fails, GDB no longer attempts to open a
4002 core file named NUMBER. Attaching to a program using the -c option
4003 is no longer supported. Instead, use the '-p' or '--pid' options.
4005 * GDB can now be built as a native debugger for debugging Windows x86
4006 (mingw32) Portable Executable (PE) programs.
4008 * Pending breakpoints no longer change their number when their address
4011 * GDB now supports breakpoints with multiple locations,
4012 including breakpoints on C++ constructors, inside C++ templates,
4013 and in inlined functions.
4015 * GDB's ability to debug optimized code has been improved. GDB more
4016 accurately identifies function bodies and lexical blocks that occupy
4017 more than one contiguous range of addresses.
4019 * Target descriptions can now describe registers for PowerPC.
4021 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4022 registers on PowerPC targets.
4024 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4025 targets even when the libthread_db library is not available.
4027 * The GDB remote stub, gdbserver, now supports the new file transfer
4028 commands (remote put, remote get, and remote delete).
4030 * The GDB remote stub, gdbserver, now supports run and attach in
4031 extended-remote mode.
4033 * hppa*64*-*-hpux11* target broken
4034 The debugger is unable to start a program and fails with the following
4035 error: "Error trying to get information about dynamic linker".
4036 The gdb-6.7 release is also affected.
4038 * GDB now supports the --enable-targets= configure option to allow
4039 building a single GDB executable that supports multiple remote
4040 target architectures.
4042 * GDB now supports debugging C and C++ programs which use the
4043 Decimal Floating Point extension. In addition, the PowerPC target
4044 now has a set of pseudo-registers to inspect decimal float values
4045 stored in two consecutive float registers.
4047 * The -break-insert MI command can optionally create pending
4050 * Improved support for debugging Ada
4051 Many improvements to the Ada language support have been made. These
4053 - Better support for Ada2005 interface types
4054 - Improved handling of arrays and slices in general
4055 - Better support for Taft-amendment types
4056 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4058 - Improved command completion in Ada
4061 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4066 set print frame-arguments (all|scalars|none)
4067 show print frame-arguments
4068 The value of this variable can be changed to control which argument
4069 values should be printed by the debugger when displaying a frame.
4074 Transfer files to and from a remote target, and delete remote files.
4081 Transfer files to and from a remote target, and delete remote files.
4083 * New remote packets
4090 Open, close, read, write, and delete files on the remote system.
4093 Attach to an existing process on the remote system, in extended-remote
4097 Run a new process on the remote system, in extended-remote mode.
4099 *** Changes in GDB 6.7
4101 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4102 bfd, libiberty and opcodes, as revealed by static analysis donated by
4103 Coverity, Inc. (http://scan.coverity.com).
4105 * When looking up multiply-defined global symbols, GDB will now prefer the
4106 symbol definition in the current shared library if it was built using the
4107 -Bsymbolic linker option.
4109 * When the Text User Interface (TUI) is not configured, GDB will now
4110 recognize the -tui command-line option and print a message that the TUI
4113 * The GDB remote stub, gdbserver, now has lower overhead for high
4114 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4116 * GDB for MIPS targets now autodetects whether a remote target provides
4117 32-bit or 64-bit register values.
4119 * Support for C++ member pointers has been improved.
4121 * GDB now understands XML target descriptions, which specify the
4122 target's overall architecture. GDB can read a description from
4123 a local file or over the remote serial protocol.
4125 * Vectors of single-byte data use a new integer type which is not
4126 automatically displayed as character or string data.
4128 * The /s format now works with the print command. It displays
4129 arrays of single-byte integers and pointers to single-byte integers
4132 * Target descriptions can now describe target-specific registers,
4133 for architectures which have implemented the support (currently
4134 only ARM, M68K, and MIPS).
4136 * GDB and the GDB remote stub, gdbserver, now support the XScale
4139 * The GDB remote stub, gdbserver, has been updated to support
4140 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4141 has been rewritten to use the standard GDB remote protocol.
4143 * GDB can now step into C++ functions which are called through thunks.
4145 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4147 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4148 layout. It also supports a TextSeg= and DataSeg= response when only
4149 segment base addresses (rather than offsets) are available.
4151 * The /i format now outputs any trailing branch delay slot instructions
4152 immediately following the last instruction within the count specified.
4154 * The GDB remote protocol "T" stop reply packet now supports a
4155 "library" response. Combined with the new "qXfer:libraries:read"
4156 packet, this response allows GDB to debug shared libraries on targets
4157 where the operating system manages the list of loaded libraries (e.g.
4158 Windows and SymbianOS).
4160 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4161 (DLLs) on Windows and Windows CE targets.
4163 * GDB now supports a faster verification that a .debug file matches its binary
4164 according to its build-id signature, if the signature is present.
4170 Enable or disable hardware flow control (RTS/CTS) on the serial port
4171 when debugging using remote targets.
4173 set mem inaccessible-by-default
4174 show mem inaccessible-by-default
4175 If the target supplies a memory map, for instance via the remote
4176 protocol's "qXfer:memory-map:read" packet, setting this variable
4177 prevents GDB from accessing memory outside the memory map. This
4178 is useful for targets with memory mapped registers or which react
4179 badly to accesses of unmapped address space.
4181 set breakpoint auto-hw
4182 show breakpoint auto-hw
4183 If the target supplies a memory map, for instance via the remote
4184 protocol's "qXfer:memory-map:read" packet, setting this variable
4185 lets GDB use hardware breakpoints automatically for memory regions
4186 where it can not use software breakpoints. This covers both the
4187 "break" command and internal breakpoints used for other commands
4188 including "next" and "finish".
4191 catch exception unhandled
4192 Stop the program execution when Ada exceptions are raised.
4195 Stop the program execution when an Ada assertion failed.
4199 Set an alternate system root for target files. This is a more
4200 general version of "set solib-absolute-prefix", which is now
4201 an alias to "set sysroot".
4204 Provide extended SPU facility status information. This set of
4205 commands is available only when debugging the Cell/B.E. SPU
4208 * New native configurations
4210 OpenBSD/sh sh*-*openbsd*
4213 unset tdesc filename
4215 Use the specified local file as an XML target description, and do
4216 not query the target for its built-in description.
4220 OpenBSD/sh sh*-*-openbsd*
4221 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4222 Toshiba Media Processor mep-elf
4224 * New remote packets
4227 Ignore the specified signals; pass them directly to the debugged program
4228 without stopping other threads or reporting them to GDB.
4230 qXfer:features:read:
4231 Read an XML target description from the target, which describes its
4236 Read or write contents of an spufs file on the target system. These
4237 packets are available only on the Cell/B.E. SPU architecture.
4239 qXfer:libraries:read:
4240 Report the loaded shared libraries. Combined with new "T" packet
4241 response, this packet allows GDB to debug shared libraries on
4242 targets where the operating system manages the list of loaded
4243 libraries (e.g. Windows and SymbianOS).
4247 Support for these obsolete configurations has been removed.
4255 i[34567]86-*-lynxos*
4256 i[34567]86-*-netware*
4257 i[34567]86-*-sco3.2v5*
4258 i[34567]86-*-sco3.2v4*
4260 i[34567]86-*-sysv4.2*
4263 i[34567]86-*-unixware2*
4264 i[34567]86-*-unixware*
4273 * Other removed features
4280 Various m68k-only ROM monitors.
4287 Various Renesas ROM monitors and debugging interfaces for SH and
4292 Support for a Macraigor serial interface to on-chip debugging.
4293 GDB does not directly support the newer parallel or USB
4298 A debug information format. The predecessor to DWARF 2 and
4299 DWARF 3, which are still supported.
4301 Support for the HP aCC compiler on HP-UX/PA-RISC
4303 SOM-encapsulated symbolic debugging information, automatic
4304 invocation of pxdb, and the aCC custom C++ ABI. This does not
4305 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4306 with aCC can still be debugged on an assembly level.
4308 MIPS ".pdr" sections
4310 A MIPS-specific format used to describe stack frame layout
4311 in debugging information.
4315 GDB could work with an older version of Guile to debug
4316 the interpreter and Scheme programs running in it.
4318 set mips stack-arg-size
4319 set mips saved-gpreg-size
4321 Use "set mips abi" to control parameter passing for MIPS.
4323 *** Changes in GDB 6.6
4328 Cell Broadband Engine SPU spu-elf
4330 * GDB can now be configured as a cross-debugger targeting native Windows
4331 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4332 running on a Windows system over TCP/IP to debug Windows programs.
4334 * The GDB remote stub, gdbserver, has been updated to support Windows and
4335 Cygwin debugging. Both single-threaded and multi-threaded programs are
4338 * The "set trust-readonly-sections" command works again. This command was
4339 broken in GDB 6.3, 6.4, and 6.5.
4341 * The "load" command now supports writing to flash memory, if the remote
4342 stub provides the required support.
4344 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4345 longer requires symbolic debug information (e.g. DWARF-2).
4350 unset substitute-path
4351 show substitute-path
4352 Manage a list of substitution rules that GDB uses to rewrite the name
4353 of the directories where the sources are located. This can be useful
4354 for instance when the sources were moved to a different location
4355 between compilation and debugging.
4359 Print each CLI command as it is executed. Each command is prefixed with
4360 a number of `+' symbols representing the nesting depth.
4361 The source command now has a `-v' option to enable the same feature.
4365 The ARM Demon monitor support (RDP protocol, "target rdp").
4367 Kernel Object Display, an embedded debugging feature which only worked with
4368 an obsolete version of Cisco IOS.
4370 The 'set download-write-size' and 'show download-write-size' commands.
4372 * New remote packets
4375 Tell a stub about GDB client features, and request remote target features.
4376 The first feature implemented is PacketSize, which allows the target to
4377 specify the size of packets it can handle - to minimize the number of
4378 packets required and improve performance when connected to a remote
4382 Fetch an OS auxilliary vector from the remote stub. This packet is a
4383 more efficient replacement for qPart:auxv:read.
4385 qXfer:memory-map:read:
4386 Fetch a memory map from the remote stub, including information about
4387 RAM, ROM, and flash memory devices.
4392 Erase and program a flash memory device.
4394 * Removed remote packets
4397 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4398 used it, and only gdbserver implemented it.
4400 *** Changes in GDB 6.5
4404 Renesas M32C/M16C m32c-elf
4406 Morpho Technologies ms1 ms1-elf
4410 init-if-undefined Initialize a convenience variable, but
4411 only if it doesn't already have a value.
4413 The following commands are presently only implemented for native GNU/Linux:
4415 checkpoint Save a snapshot of the program state.
4417 restart <n> Return the program state to a
4418 previously saved state.
4420 info checkpoints List currently saved checkpoints.
4422 delete-checkpoint <n> Delete a previously saved checkpoint.
4424 set|show detach-on-fork Tell gdb whether to detach from a newly
4425 forked process, or to keep debugging it.
4427 info forks List forks of the user program that
4428 are available to be debugged.
4430 fork <n> Switch to debugging one of several
4431 forks of the user program that are
4432 available to be debugged.
4434 delete-fork <n> Delete a fork from the list of forks
4435 that are available to be debugged (and
4436 kill the forked process).
4438 detach-fork <n> Delete a fork from the list of forks
4439 that are available to be debugged (and
4440 allow the process to continue).
4444 Morpho Technologies ms2 ms1-elf
4446 * Improved Windows host support
4448 GDB now builds as a cross debugger hosted on i686-mingw32, including
4449 native console support, and remote communications using either
4450 network sockets or serial ports.
4452 * Improved Modula-2 language support
4454 GDB can now print most types in the Modula-2 syntax. This includes:
4455 basic types, set types, record types, enumerated types, range types,
4456 pointer types and ARRAY types. Procedure var parameters are correctly
4457 printed and hexadecimal addresses and character constants are also
4458 written in the Modula-2 syntax. Best results can be obtained by using
4459 GNU Modula-2 together with the -gdwarf-2 command line option.
4463 The ARM rdi-share module.
4465 The Netware NLM debug server.
4467 *** Changes in GDB 6.4
4469 * New native configurations
4471 OpenBSD/arm arm*-*-openbsd*
4472 OpenBSD/mips64 mips64-*-openbsd*
4476 Morpho Technologies ms1 ms1-elf
4478 * New command line options
4480 --batch-silent As for --batch, but totally silent.
4481 --return-child-result The debugger will exist with the same value
4482 the child (debugged) program exited with.
4483 --eval-command COMMAND, -ex COMMAND
4484 Execute a single GDB CLI command. This may be
4485 specified multiple times and in conjunction
4486 with the --command (-x) option.
4488 * Deprecated commands removed
4490 The following commands, that were deprecated in 2000, have been
4494 set|show arm disassembly-flavor set|show arm disassembler
4495 othernames set arm disassembler
4496 set|show remotedebug set|show debug remote
4497 set|show archdebug set|show debug arch
4498 set|show eventdebug set|show debug event
4501 * New BSD user-level threads support
4503 It is now possible to debug programs using the user-level threads
4504 library on OpenBSD and FreeBSD. Currently supported (target)
4507 FreeBSD/amd64 x86_64-*-freebsd*
4508 FreeBSD/i386 i386-*-freebsd*
4509 OpenBSD/i386 i386-*-openbsd*
4511 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4512 are not yet supported.
4514 * New support for Matsushita MN10300 w/sim added
4515 (Work in progress). mn10300-elf.
4517 * REMOVED configurations and files
4519 VxWorks and the XDR protocol *-*-vxworks
4520 Motorola MCORE mcore-*-*
4521 National Semiconductor NS32000 ns32k-*-*
4523 * New "set print array-indexes" command
4525 After turning this setting "on", GDB prints the index of each element
4526 when displaying arrays. The default is "off" to preserve the previous
4529 * VAX floating point support
4531 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4533 * User-defined command support
4535 In addition to using $arg0..$arg9 for argument passing, it is now possible
4536 to use $argc to determine now many arguments have been passed. See the
4537 section on user-defined commands in the user manual for more information.
4539 *** Changes in GDB 6.3:
4541 * New command line option
4543 GDB now accepts -l followed by a number to set the timeout for remote
4546 * GDB works with GCC -feliminate-dwarf2-dups
4548 GDB now supports a more compact representation of DWARF-2 debug
4549 information using DW_FORM_ref_addr references. These are produced
4550 by GCC with the option -feliminate-dwarf2-dups and also by some
4551 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4552 to use -feliminate-dwarf2-dups.
4554 * Internationalization
4556 When supported by the host system, GDB will be built with
4557 internationalization (libintl). The task of marking up the sources is
4558 continued, we're looking forward to our first translation.
4562 Initial support for debugging programs compiled with the GNAT
4563 implementation of the Ada programming language has been integrated
4564 into GDB. In this release, support is limited to expression evaluation.
4566 * New native configurations
4568 GNU/Linux/m32r m32r-*-linux-gnu
4572 GDB's remote protocol now includes support for the 'p' packet. This
4573 packet is used to fetch individual registers from a remote inferior.
4575 * END-OF-LIFE registers[] compatibility module
4577 GDB's internal register infrastructure has been completely rewritten.
4578 The new infrastructure making possible the implementation of key new
4579 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4582 GDB 6.3 will be the last release to include the the registers[]
4583 compatibility module that allowed out-of-date configurations to
4584 continue to work. This change directly impacts the following
4594 powerpc bdm protocol
4596 Unless there is activity to revive these configurations, they will be
4597 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4599 * OBSOLETE configurations and files
4601 Configurations that have been declared obsolete in this release have
4602 been commented out. Unless there is activity to revive these
4603 configurations, the next release of GDB will have their sources
4604 permanently REMOVED.
4613 *** Changes in GDB 6.2.1:
4615 * MIPS `break main; run' gave an heuristic-fence-post warning
4617 When attempting to run even a simple program, a warning about
4618 heuristic-fence-post being hit would be reported. This problem has
4621 * MIPS IRIX 'long double' crashed GDB
4623 When examining a long double variable, GDB would get a segmentation
4624 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4625 IRIX long double values).
4629 A bug in the VAX stack code was causing problems with the "next"
4630 command. This problem has been fixed.
4632 *** Changes in GDB 6.2:
4634 * Fix for ``many threads''
4636 On GNU/Linux systems that use the NPTL threads library, a program
4637 rapidly creating and deleting threads would confuse GDB leading to the
4640 ptrace: No such process.
4641 thread_db_get_info: cannot get thread info: generic error
4643 This problem has been fixed.
4645 * "-async" and "-noasync" options removed.
4647 Support for the broken "-noasync" option has been removed (it caused
4650 * New ``start'' command.
4652 This command runs the program until the begining of the main procedure.
4654 * New BSD Kernel Data Access Library (libkvm) interface
4656 Using ``target kvm'' it is now possible to debug kernel core dumps and
4657 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4658 platforms. Currently supported (native-only) configurations are:
4660 FreeBSD/amd64 x86_64-*-freebsd*
4661 FreeBSD/i386 i?86-*-freebsd*
4662 NetBSD/i386 i?86-*-netbsd*
4663 NetBSD/m68k m68*-*-netbsd*
4664 NetBSD/sparc sparc-*-netbsd*
4665 OpenBSD/amd64 x86_64-*-openbsd*
4666 OpenBSD/i386 i?86-*-openbsd*
4667 OpenBSD/m68k m68*-openbsd*
4668 OpenBSD/sparc sparc-*-openbsd*
4670 * Signal trampoline code overhauled
4672 Many generic problems with GDB's signal handling code have been fixed.
4673 These include: backtraces through non-contiguous stacks; recognition
4674 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4675 call; backtrace through a signal trampoline; step into and out of
4676 signal handlers; and single-stepping in the signal trampoline.
4678 Please note that kernel bugs are a limiting factor here. These
4679 features have been shown to work on an s390 GNU/Linux system that
4680 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4682 * Cygwin support for DWARF 2 added.
4684 * New native configurations
4686 GNU/Linux/hppa hppa*-*-linux*
4687 OpenBSD/hppa hppa*-*-openbsd*
4688 OpenBSD/m68k m68*-*-openbsd*
4689 OpenBSD/m88k m88*-*-openbsd*
4690 OpenBSD/powerpc powerpc-*-openbsd*
4691 NetBSD/vax vax-*-netbsd*
4692 OpenBSD/vax vax-*-openbsd*
4694 * END-OF-LIFE frame compatibility module
4696 GDB's internal frame infrastructure has been completely rewritten.
4697 The new infrastructure making it possible to support key new features
4698 including DWARF 2 Call Frame Information. To aid in the task of
4699 migrating old configurations to this new infrastructure, a
4700 compatibility module, that allowed old configurations to continue to
4701 work, was also included.
4703 GDB 6.2 will be the last release to include this frame compatibility
4704 module. This change directly impacts the following configurations:
4714 Unless there is activity to revive these configurations, they will be
4715 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4717 * REMOVED configurations and files
4719 Sun 3, running SunOS 3 m68*-*-sunos3*
4720 Sun 3, running SunOS 4 m68*-*-sunos4*
4721 Sun 2, running SunOS 3 m68000-*-sunos3*
4722 Sun 2, running SunOS 4 m68000-*-sunos4*
4723 Motorola 680x0 running LynxOS m68*-*-lynxos*
4724 AT&T 3b1/Unix pc m68*-att-*
4725 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4726 decstation mips-dec-* mips-little-*
4727 riscos mips-*-riscos* mips-*-sysv*
4728 sonymips mips-sony-*
4729 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4731 *** Changes in GDB 6.1.1:
4733 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4735 The TUI (Text-mode User Interface) is now built as part of a default
4736 GDB configuration. It is enabled by either selecting the TUI with the
4737 command line option "-i=tui" or by running the separate "gdbtui"
4738 program. For more information on the TUI, see the manual "Debugging
4741 * Pending breakpoint support (also included in GDB 6.1)
4743 Support has been added to allow you to specify breakpoints in shared
4744 libraries that have not yet been loaded. If a breakpoint location
4745 cannot be found, and the "breakpoint pending" option is set to auto,
4746 GDB queries you if you wish to make the breakpoint pending on a future
4747 shared-library load. If and when GDB resolves the breakpoint symbol,
4748 the pending breakpoint is removed as one or more regular breakpoints
4751 Pending breakpoints are very useful for GCJ Java debugging.
4753 * Fixed ISO-C build problems
4755 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4756 non ISO-C code that stopped them being built using a more strict ISO-C
4757 compiler (e.g., IBM's C compiler).
4759 * Fixed build problem on IRIX 5
4761 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4762 wasn't able to compile compile on an IRIX 5 system.
4764 * Added execute permission to gdb/gdbserver/configure
4766 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4767 permission. This bug would cause configure to fail on a number of
4768 systems (Solaris, IRIX). Ref: server/519.
4770 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4772 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4773 has been updated to use constant array sizes.
4775 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4777 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4778 its generated DWARF Call Frame Info. This encoding was causing GDB to
4779 panic, that panic has been fixed. Ref: gdb/1628.
4781 * Fixed a problem when examining parameters in shared library code.
4783 When examining parameters in optimized shared library code generated
4784 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4785 not available''. GDB now correctly displays the variable's value.
4787 *** Changes in GDB 6.1:
4789 * Removed --with-mmalloc
4791 Support for the mmalloc memory manager has been removed, as it
4792 conflicted with the internal gdb byte cache.
4794 * Changes in AMD64 configurations
4796 The AMD64 target now includes the %cs and %ss registers. As a result
4797 the AMD64 remote protocol has changed; this affects the floating-point
4798 and SSE registers. If you rely on those registers for your debugging,
4799 you should upgrade gdbserver on the remote side.
4801 * Revised SPARC target
4803 The SPARC target has been completely revised, incorporating the
4804 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4805 support for LynxOS and SunOS 4 has been dropped. Calling functions
4806 from within GDB on operating systems with a non-executable stack
4807 (Solaris, OpenBSD) now works.
4811 GDB has a new C++ demangler which does a better job on the mangled
4812 names generated by current versions of g++. It also runs faster, so
4813 with this and other changes gdb should now start faster on large C++
4816 * DWARF 2 Location Expressions
4818 GDB support for location expressions has been extended to support function
4819 arguments and frame bases. Older versions of GDB could crash when they
4822 * C++ nested types and namespaces
4824 GDB's support for nested types and namespaces in C++ has been
4825 improved, especially if you use the DWARF 2 debugging format. (This
4826 is the default for recent versions of GCC on most platforms.)
4827 Specifically, if you have a class "Inner" defined within a class or
4828 namespace "Outer", then GDB realizes that the class's name is
4829 "Outer::Inner", not simply "Inner". This should greatly reduce the
4830 frequency of complaints about not finding RTTI symbols. In addition,
4831 if you are stopped at inside of a function defined within a namespace,
4832 GDB modifies its name lookup accordingly.
4834 * New native configurations
4836 NetBSD/amd64 x86_64-*-netbsd*
4837 OpenBSD/amd64 x86_64-*-openbsd*
4838 OpenBSD/alpha alpha*-*-openbsd*
4839 OpenBSD/sparc sparc-*-openbsd*
4840 OpenBSD/sparc64 sparc64-*-openbsd*
4842 * New debugging protocols
4844 M32R with SDI protocol m32r-*-elf*
4846 * "set prompt-escape-char" command deleted.
4848 The command "set prompt-escape-char" has been deleted. This command,
4849 and its very obscure effet on GDB's prompt, was never documented,
4850 tested, nor mentioned in the NEWS file.
4852 * OBSOLETE configurations and files
4854 Configurations that have been declared obsolete in this release have
4855 been commented out. Unless there is activity to revive these
4856 configurations, the next release of GDB will have their sources
4857 permanently REMOVED.
4859 Sun 3, running SunOS 3 m68*-*-sunos3*
4860 Sun 3, running SunOS 4 m68*-*-sunos4*
4861 Sun 2, running SunOS 3 m68000-*-sunos3*
4862 Sun 2, running SunOS 4 m68000-*-sunos4*
4863 Motorola 680x0 running LynxOS m68*-*-lynxos*
4864 AT&T 3b1/Unix pc m68*-att-*
4865 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4866 decstation mips-dec-* mips-little-*
4867 riscos mips-*-riscos* mips-*-sysv*
4868 sonymips mips-sony-*
4869 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4871 * REMOVED configurations and files
4873 SGI Irix-4.x mips-sgi-irix4 or iris4
4874 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4875 Z8000 simulator z8k-zilog-none or z8ksim
4876 Matsushita MN10200 w/simulator mn10200-*-*
4877 H8/500 simulator h8500-hitachi-hms or h8500hms
4878 HP/PA running BSD hppa*-*-bsd*
4879 HP/PA running OSF/1 hppa*-*-osf*
4880 HP/PA Pro target hppa*-*-pro*
4881 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4882 386BSD i[3456]86-*-bsd*
4883 Sequent family i[3456]86-sequent-sysv4*
4884 i[3456]86-sequent-sysv*
4885 i[3456]86-sequent-bsd*
4886 SPARC running LynxOS sparc-*-lynxos*
4887 SPARC running SunOS 4 sparc-*-sunos4*
4888 Tsqware Sparclet sparclet-*-*
4889 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4891 *** Changes in GDB 6.0:
4895 Support for debugging the Objective-C programming language has been
4896 integrated into GDB.
4898 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4900 DWARF 2's Call Frame Information makes available compiler generated
4901 information that more exactly describes the program's run-time stack.
4902 By using this information, GDB is able to provide more robust stack
4905 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4906 have been updated to use a new backtrace mechanism which includes
4907 DWARF 2 CFI support.
4911 GDB's remote protocol has been extended to include support for hosted
4912 file I/O (where the remote target uses GDB's file system). See GDB's
4913 remote protocol documentation for details.
4915 * All targets using the new architecture framework.
4917 All of GDB's targets have been updated to use the new internal
4918 architecture framework. The way is now open for future GDB releases
4919 to include cross-architecture native debugging support (i386 on amd64,
4922 * GNU/Linux's Thread Local Storage (TLS)
4924 GDB now includes support for for the GNU/Linux implementation of
4925 per-thread variables.
4927 * GNU/Linux's Native POSIX Thread Library (NPTL)
4929 GDB's thread code has been updated to work with either the new
4930 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4932 * Separate debug info.
4934 GDB, in conjunction with BINUTILS, now supports a mechanism for
4935 automatically loading debug information from a separate file. Instead
4936 of shipping full debug and non-debug versions of system libraries,
4937 system integrators can now instead ship just the stripped libraries
4938 and optional debug files.
4940 * DWARF 2 Location Expressions
4942 DWARF 2 Location Expressions allow the compiler to more completely
4943 describe the location of variables (even in optimized code) to the
4946 GDB now includes preliminary support for location expressions (support
4947 for DW_OP_piece is still missing).
4951 A number of long standing bugs that caused GDB to die while starting a
4952 Java application have been fixed. GDB's Java support is now
4953 considered "useable".
4955 * GNU/Linux support for fork, vfork, and exec.
4957 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4958 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4961 * GDB supports logging output to a file
4963 There are two new commands, "set logging" and "show logging", which can be
4964 used to capture GDB's output to a file.
4966 * The meaning of "detach" has changed for gdbserver
4968 The "detach" command will now resume the application, as documented. To
4969 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4972 * d10v, m68hc11 `regs' command deprecated
4974 The `info registers' command has been updated so that it displays the
4975 registers using a format identical to the old `regs' command.
4979 A new command, "maint set profile on/off", has been added. This command can
4980 be used to enable or disable profiling while running GDB, to profile a
4981 session or a set of commands. In addition there is a new configure switch,
4982 "--enable-profiling", which will cause GDB to be compiled with profiling
4983 data, for more informative profiling results.
4985 * Default MI syntax changed to "mi2".
4987 The default MI (machine interface) syntax, enabled by the command line
4988 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4989 "mi1", can be enabled by specifying the option "-i=mi1".
4991 Support for the original "mi0" syntax (included in GDB 5.0) has been
4994 Fix for gdb/192: removed extraneous space when displaying frame level.
4995 Fix for gdb/672: update changelist is now output in mi list format.
4996 Fix for gdb/702: a -var-assign that updates the value now shows up
4997 in a subsequent -var-update.
4999 * New native configurations.
5001 FreeBSD/amd64 x86_64-*-freebsd*
5003 * Multi-arched targets.
5005 HP/PA HPUX11 hppa*-*-hpux*
5006 Renesas M32R/D w/simulator m32r-*-elf*
5008 * OBSOLETE configurations and files
5010 Configurations that have been declared obsolete in this release have
5011 been commented out. Unless there is activity to revive these
5012 configurations, the next release of GDB will have their sources
5013 permanently REMOVED.
5015 Z8000 simulator z8k-zilog-none or z8ksim
5016 Matsushita MN10200 w/simulator mn10200-*-*
5017 H8/500 simulator h8500-hitachi-hms or h8500hms
5018 HP/PA running BSD hppa*-*-bsd*
5019 HP/PA running OSF/1 hppa*-*-osf*
5020 HP/PA Pro target hppa*-*-pro*
5021 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5022 Sequent family i[3456]86-sequent-sysv4*
5023 i[3456]86-sequent-sysv*
5024 i[3456]86-sequent-bsd*
5025 Tsqware Sparclet sparclet-*-*
5026 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5028 * REMOVED configurations and files
5031 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5032 IBM AIX PS/2 i[3456]86-*-aix
5033 i386 running Mach 3.0 i[3456]86-*-mach3*
5034 i386 running Mach i[3456]86-*-mach*
5035 i386 running OSF/1 i[3456]86-*osf1mk*
5036 HP/Apollo 68k Family m68*-apollo*-sysv*,
5038 m68*-hp-bsd*, m68*-hp-hpux*
5039 Argonaut Risc Chip (ARC) arc-*-*
5040 Mitsubishi D30V d30v-*-*
5041 Fujitsu FR30 fr30-*-elf*
5042 OS/9000 i[34]86-*-os9k
5043 I960 with MON960 i960-*-coff
5045 * MIPS $fp behavior changed
5047 The convenience variable $fp, for the MIPS, now consistently returns
5048 the address of the current frame's base. Previously, depending on the
5049 context, $fp could refer to either $sp or the current frame's base
5050 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5051 The GNU Source-Level Debugger''.
5053 *** Changes in GDB 5.3:
5055 * GNU/Linux shared library multi-threaded performance improved.
5057 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5058 `/proc', in preference to `ptrace' for memory reads. This may result
5059 in an improvement in the start-up time of multi-threaded, shared
5060 library applications when run under GDB. One GDB user writes: ``loads
5061 shared libs like mad''.
5063 * ``gdbserver'' now supports multi-threaded applications on some targets
5065 Support for debugging multi-threaded applications which use
5066 the GNU/Linux LinuxThreads package has been added for
5067 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5068 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5070 * GDB now supports C/C++ preprocessor macros.
5072 GDB now expands preprocessor macro invocations in C/C++ expressions,
5073 and provides various commands for showing macro definitions and how
5076 The new command `macro expand EXPRESSION' expands any macro
5077 invocations in expression, and shows the result.
5079 The new command `show macro MACRO-NAME' shows the definition of the
5080 macro named MACRO-NAME, and where it was defined.
5082 Most compilers don't include information about macros in the debugging
5083 information by default. In GCC 3.1, for example, you need to compile
5084 your program with the options `-gdwarf-2 -g3'. If the macro
5085 information is present in the executable, GDB will read it.
5087 * Multi-arched targets.
5089 DEC Alpha (partial) alpha*-*-*
5090 DEC VAX (partial) vax-*-*
5092 National Semiconductor NS32000 (partial) ns32k-*-*
5093 Motorola 68000 (partial) m68k-*-*
5094 Motorola MCORE mcore-*-*
5098 Fujitsu FRV architecture added by Red Hat frv*-*-*
5101 * New native configurations
5103 Alpha NetBSD alpha*-*-netbsd*
5104 SH NetBSD sh*-*-netbsdelf*
5105 MIPS NetBSD mips*-*-netbsd*
5106 UltraSPARC NetBSD sparc64-*-netbsd*
5108 * OBSOLETE configurations and files
5110 Configurations that have been declared obsolete in this release have
5111 been commented out. Unless there is activity to revive these
5112 configurations, the next release of GDB will have their sources
5113 permanently REMOVED.
5115 Mitsubishi D30V d30v-*-*
5116 OS/9000 i[34]86-*-os9k
5117 IBM AIX PS/2 i[3456]86-*-aix
5118 Fujitsu FR30 fr30-*-elf*
5119 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5120 Argonaut Risc Chip (ARC) arc-*-*
5121 i386 running Mach 3.0 i[3456]86-*-mach3*
5122 i386 running Mach i[3456]86-*-mach*
5123 i386 running OSF/1 i[3456]86-*osf1mk*
5124 HP/Apollo 68k Family m68*-apollo*-sysv*,
5126 m68*-hp-bsd*, m68*-hp-hpux*
5127 I960 with MON960 i960-*-coff
5129 * OBSOLETE languages
5131 CHILL, a Pascal like language used by telecommunications companies.
5133 * REMOVED configurations and files
5135 AMD 29k family via UDI a29k-amd-udi, udi29k
5136 A29K VxWorks a29k-*-vxworks
5137 AMD 29000 embedded, using EBMON a29k-none-none
5138 AMD 29000 embedded with COFF a29k-none-coff
5139 AMD 29000 embedded with a.out a29k-none-aout
5141 testsuite/gdb.hp/gdb.threads-hp/ directory
5143 * New command "set max-user-call-depth <nnn>"
5145 This command allows the user to limit the call depth of user-defined
5146 commands. The default is 1024.
5148 * Changes in FreeBSD/i386 native debugging.
5150 Support for the "generate-core-file" has been added.
5152 * New commands "dump", "append", and "restore".
5154 These commands allow data to be copied from target memory
5155 to a bfd-format or binary file (dump and append), and back
5156 from a file into memory (restore).
5158 * Improved "next/step" support on multi-processor Alpha Tru64.
5160 The previous single-step mechanism could cause unpredictable problems,
5161 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5162 of a software single-step mechanism prevents this.
5164 *** Changes in GDB 5.2.1:
5172 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5173 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5174 Fix, by Joel Brobecker imported from mainline.
5176 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5177 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5178 Fix, by Fred Fish, imported from mainline.
5180 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5181 Surprisingly enough, it works now.
5182 By Michal Ludvig, imported from mainline.
5184 i386 hardware watchpoint support:
5185 avoid misses on second run for some targets.
5186 By Pierre Muller, imported from mainline.
5188 *** Changes in GDB 5.2:
5190 * New command "set trust-readonly-sections on[off]".
5192 This command is a hint that tells gdb that read-only sections
5193 really are read-only (ie. that their contents will not change).
5194 In this mode, gdb will go to the object file rather than the
5195 target to read memory from read-only sections (such as ".text").
5196 This can be a significant performance improvement on some
5197 (notably embedded) targets.
5199 * New command "generate-core-file" (or "gcore").
5201 This new gdb command allows the user to drop a core file of the child
5202 process state at any time. So far it's been implemented only for
5203 GNU/Linux and Solaris, but should be relatively easily ported to other
5204 hosts. Argument is core file name (defaults to core.<pid>).
5206 * New command line option
5208 GDB now accepts --pid or -p followed by a process id.
5210 * Change in command line behavior -- corefiles vs. process ids.
5212 There is a subtle behavior in the way in which GDB handles
5213 command line arguments. The first non-flag argument is always
5214 a program to debug, but the second non-flag argument may either
5215 be a corefile or a process id. Previously, GDB would attempt to
5216 open the second argument as a corefile, and if that failed, would
5217 issue a superfluous error message and then attempt to attach it as
5218 a process. Now, if the second argument begins with a non-digit,
5219 it will be treated as a corefile. If it begins with a digit,
5220 GDB will attempt to attach it as a process, and if no such process
5221 is found, will then attempt to open it as a corefile.
5223 * Changes in ARM configurations.
5225 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5226 configuration is fully multi-arch.
5228 * New native configurations
5230 ARM NetBSD arm*-*-netbsd*
5231 x86 OpenBSD i[3456]86-*-openbsd*
5232 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5233 Sparc64 running FreeBSD sparc64-*-freebsd*
5237 Sanyo XStormy16 xstormy16-elf
5239 * OBSOLETE configurations and files
5241 Configurations that have been declared obsolete in this release have
5242 been commented out. Unless there is activity to revive these
5243 configurations, the next release of GDB will have their sources
5244 permanently REMOVED.
5246 AMD 29k family via UDI a29k-amd-udi, udi29k
5247 A29K VxWorks a29k-*-vxworks
5248 AMD 29000 embedded, using EBMON a29k-none-none
5249 AMD 29000 embedded with COFF a29k-none-coff
5250 AMD 29000 embedded with a.out a29k-none-aout
5252 testsuite/gdb.hp/gdb.threads-hp/ directory
5254 * REMOVED configurations and files
5256 TI TMS320C80 tic80-*-*
5258 PowerPC Solaris powerpcle-*-solaris*
5259 PowerPC Windows NT powerpcle-*-cygwin32
5260 PowerPC Netware powerpc-*-netware*
5261 Harris/CXUX m88k m88*-harris-cxux*
5262 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5263 ns32k-utek-sysv* ns32k-utek-*
5264 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5265 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5266 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5267 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5268 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5270 * Changes to command line processing
5272 The new `--args' feature can be used to specify command-line arguments
5273 for the inferior from gdb's command line.
5275 * Changes to key bindings
5277 There is a new `operate-and-get-next' function bound to `C-o'.
5279 *** Changes in GDB 5.1.1
5281 Fix compile problem on DJGPP.
5283 Fix a problem with floating-point registers on the i386 being
5286 Fix to stop GDB crashing on .debug_str debug info.
5288 Numerous documentation fixes.
5290 Numerous testsuite fixes.
5292 *** Changes in GDB 5.1:
5294 * New native configurations
5296 Alpha FreeBSD alpha*-*-freebsd*
5297 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5298 MIPS GNU/Linux mips*-*-linux*
5299 MIPS SGI Irix 6.x mips*-sgi-irix6*
5300 ia64 AIX ia64-*-aix*
5301 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5305 Motorola 68HC11 and 68HC12 m68hc11-elf
5307 UltraSparc running GNU/Linux sparc64-*-linux*
5309 * OBSOLETE configurations and files
5311 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5312 Harris/CXUX m88k m88*-harris-cxux*
5313 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5314 ns32k-utek-sysv* ns32k-utek-*
5315 TI TMS320C80 tic80-*-*
5317 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5318 PowerPC Solaris powerpcle-*-solaris*
5319 PowerPC Windows NT powerpcle-*-cygwin32
5320 PowerPC Netware powerpc-*-netware*
5321 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5322 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5323 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5324 Apple Macintosh (MPW) host N/A
5326 stuff.c (Program to stuff files into a specially prepared space in kdb)
5327 kdb-start.c (Main loop for the standalone kernel debugger)
5329 Configurations that have been declared obsolete in this release have
5330 been commented out. Unless there is activity to revive these
5331 configurations, the next release of GDB will have their sources
5332 permanently REMOVED.
5334 * REMOVED configurations and files
5336 Altos 3068 m68*-altos-*
5337 Convex c1-*-*, c2-*-*
5339 ARM RISCix arm-*-* (as host)
5343 * GDB has been converted to ISO C.
5345 GDB's source code has been converted to ISO C. In particular, the
5346 sources are fully protoized, and rely on standard headers being
5351 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5353 * The MI enabled by default.
5355 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5356 revised and enabled by default. Packages which use GDB as a debugging
5357 engine behind a UI or another front end are encouraged to switch to
5358 using the GDB/MI interface, instead of the old annotations interface
5359 which is now deprecated.
5361 * Support for debugging Pascal programs.
5363 GDB now includes support for debugging Pascal programs. The following
5364 main features are supported:
5366 - Pascal-specific data types such as sets;
5368 - automatic recognition of Pascal sources based on file-name
5371 - Pascal-style display of data types, variables, and functions;
5373 - a Pascal expression parser.
5375 However, some important features are not yet supported.
5377 - Pascal string operations are not supported at all;
5379 - there are some problems with boolean types;
5381 - Pascal type hexadecimal constants are not supported
5382 because they conflict with the internal variables format;
5384 - support for Pascal objects and classes is not full yet;
5386 - unlike Pascal, GDB is case-sensitive for symbol names.
5388 * Changes in completion.
5390 Commands such as `shell', `run' and `set args', which pass arguments
5391 to inferior programs, now complete on file names, similar to what
5392 users expect at the shell prompt.
5394 Commands which accept locations, such as `disassemble', `print',
5395 `breakpoint', `until', etc. now complete on filenames as well as
5396 program symbols. Thus, if you type "break foob TAB", and the source
5397 files linked into the programs include `foobar.c', that file name will
5398 be one of the candidates for completion. However, file names are not
5399 considered for completion after you typed a colon that delimits a file
5400 name from a name of a function in that file, as in "break foo.c:bar".
5402 `set demangle-style' completes on available demangling styles.
5404 * New platform-independent commands:
5406 It is now possible to define a post-hook for a command as well as a
5407 hook that runs before the command. For more details, see the
5408 documentation of `hookpost' in the GDB manual.
5410 * Changes in GNU/Linux native debugging.
5412 Support for debugging multi-threaded programs has been completely
5413 revised for all platforms except m68k and sparc. You can now debug as
5414 many threads as your system allows you to have.
5416 Attach/detach is supported for multi-threaded programs.
5418 Support for SSE registers was added for x86. This doesn't work for
5419 multi-threaded programs though.
5421 * Changes in MIPS configurations.
5423 Multi-arch support is enabled for all MIPS configurations.
5425 GDB can now be built as native debugger on SGI Irix 6.x systems for
5426 debugging n32 executables. (Debugging 64-bit executables is not yet
5429 * Unified support for hardware watchpoints in all x86 configurations.
5431 Most (if not all) native x86 configurations support hardware-assisted
5432 breakpoints and watchpoints in a unified manner. This support
5433 implements debug register sharing between watchpoints, which allows to
5434 put a virtually infinite number of watchpoints on the same address,
5435 and also supports watching regions up to 16 bytes with several debug
5438 The new maintenance command `maintenance show-debug-regs' toggles
5439 debugging print-outs in functions that insert, remove, and test
5440 watchpoints and hardware breakpoints.
5442 * Changes in the DJGPP native configuration.
5444 New command ``info dos sysinfo'' displays assorted information about
5445 the CPU, OS, memory, and DPMI server.
5447 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5448 display information about segment descriptors stored in GDT, LDT, and
5451 New commands ``info dos pde'' and ``info dos pte'' display entries
5452 from Page Directory and Page Tables (for now works with CWSDPMI only).
5453 New command ``info dos address-pte'' displays the Page Table entry for
5454 a given linear address.
5456 GDB can now pass command lines longer than 126 characters to the
5457 program being debugged (requires an update to the libdbg.a library
5458 which is part of the DJGPP development kit).
5460 DWARF2 debug info is now supported.
5462 It is now possible to `step' and `next' through calls to `longjmp'.
5464 * Changes in documentation.
5466 All GDB documentation was converted to GFDL, the GNU Free
5467 Documentation License.
5469 Tracepoints-related commands are now fully documented in the GDB
5472 TUI, the Text-mode User Interface, is now documented in the manual.
5474 Tracepoints-related commands are now fully documented in the GDB
5477 The "GDB Internals" manual now has an index. It also includes
5478 documentation of `ui_out' functions, GDB coding standards, x86
5479 hardware watchpoints, and memory region attributes.
5481 * GDB's version number moved to ``version.in''
5483 The Makefile variable VERSION has been replaced by the file
5484 ``version.in''. People creating GDB distributions should update the
5485 contents of this file.
5489 GUD support is now a standard part of the EMACS distribution.
5491 *** Changes in GDB 5.0:
5493 * Improved support for debugging FP programs on x86 targets
5495 Unified and much-improved support for debugging floating-point
5496 programs on all x86 targets. In particular, ``info float'' now
5497 displays the FP registers in the same format on all x86 targets, with
5498 greater level of detail.
5500 * Improvements and bugfixes in hardware-assisted watchpoints
5502 It is now possible to watch array elements, struct members, and
5503 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5504 on x86 targets no longer erroneously trigger when the address is
5507 * Improvements in the native DJGPP version of GDB
5509 The distribution now includes all the scripts and auxiliary files
5510 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5511 machines ``out of the box''.
5513 The DJGPP version can now debug programs that use signals. It is
5514 possible to catch signals that happened in the debuggee, deliver
5515 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5516 would kill the program being debugged.) Programs that hook hardware
5517 interrupts (keyboard, timer, etc.) can also be debugged.
5519 It is now possible to debug DJGPP programs that redirect their
5520 standard handles or switch them to raw (as opposed to cooked) mode, or
5521 even close them. The command ``run < foo > bar'' works as expected,
5522 and ``info terminal'' reports useful information about the debuggee's
5523 terminal, including raw/cooked mode, redirection, etc.
5525 The DJGPP version now uses termios functions for console I/O, which
5526 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5529 DOS-style file names with drive letters are now fully supported by
5532 It is now possible to debug DJGPP programs that switch their working
5533 directory. It is also possible to rerun the debuggee any number of
5534 times without restarting GDB; thus, you can use the same setup,
5535 breakpoints, etc. for many debugging sessions.
5537 * New native configurations
5539 ARM GNU/Linux arm*-*-linux*
5540 PowerPC GNU/Linux powerpc-*-linux*
5544 Motorola MCore mcore-*-*
5545 x86 VxWorks i[3456]86-*-vxworks*
5546 PowerPC VxWorks powerpc-*-vxworks*
5547 TI TMS320C80 tic80-*-*
5549 * OBSOLETE configurations
5551 Altos 3068 m68*-altos-*
5552 Convex c1-*-*, c2-*-*
5554 ARM RISCix arm-*-* (as host)
5557 Configurations that have been declared obsolete will be commented out,
5558 but the code will be left in place. If there is no activity to revive
5559 these configurations before the next release of GDB, the sources will
5560 be permanently REMOVED.
5562 * Gould support removed
5564 Support for the Gould PowerNode and NP1 has been removed.
5566 * New features for SVR4
5568 On SVR4 native platforms (such as Solaris), if you attach to a process
5569 without first loading a symbol file, GDB will now attempt to locate and
5570 load symbols from the running process's executable file.
5572 * Many C++ enhancements
5574 C++ support has been greatly improved. Overload resolution now works properly
5575 in almost all cases. RTTI support is on the way.
5577 * Remote targets can connect to a sub-program
5579 A popen(3) style serial-device has been added. This device starts a
5580 sub-process (such as a stand-alone simulator) and then communicates
5581 with that. The sub-program to run is specified using the syntax
5582 ``|<program> <args>'' vis:
5584 (gdb) set remotedebug 1
5585 (gdb) target extended-remote |mn10300-elf-sim program-args
5587 * MIPS 64 remote protocol
5589 A long standing bug in the mips64 remote protocol where by GDB
5590 expected certain 32 bit registers (ex SR) to be transfered as 32
5591 instead of 64 bits has been fixed.
5593 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5594 added to provide backward compatibility with older versions of GDB.
5596 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5598 The command ``set remotebinarydownload'' command has been replaced by
5599 ``set remote X-packet''. Other commands in ``set remote'' family
5600 include ``set remote P-packet''.
5602 * Breakpoint commands accept ranges.
5604 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5605 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5606 ``tracepoint passcount'' also accepts a range of tracepoints.
5608 * ``apropos'' command added.
5610 The ``apropos'' command searches through command names and
5611 documentation strings, printing out matches, making it much easier to
5612 try to find a command that does what you are looking for.
5616 A new machine oriented interface (MI) has been added to GDB. This
5617 interface is designed for debug environments running GDB as a separate
5618 process. This is part of the long term libGDB project. See the
5619 "GDB/MI" chapter of the GDB manual for further information. It can be
5620 enabled by configuring with:
5622 .../configure --enable-gdbmi
5624 *** Changes in GDB-4.18:
5626 * New native configurations
5628 HP-UX 10.20 hppa*-*-hpux10.20
5629 HP-UX 11.x hppa*-*-hpux11.0*
5630 M68K GNU/Linux m68*-*-linux*
5634 Fujitsu FR30 fr30-*-elf*
5635 Intel StrongARM strongarm-*-*
5636 Mitsubishi D30V d30v-*-*
5638 * OBSOLETE configurations
5640 Gould PowerNode, NP1 np1-*-*, pn-*-*
5642 Configurations that have been declared obsolete will be commented out,
5643 but the code will be left in place. If there is no activity to revive
5644 these configurations before the next release of GDB, the sources will
5645 be permanently REMOVED.
5649 As a compatibility experiment, GDB's source files buildsym.h and
5650 buildsym.c have been converted to pure standard C, no longer
5651 containing any K&R compatibility code. We believe that all systems in
5652 use today either come with a standard C compiler, or have a GCC port
5653 available. If this is not true, please report the affected
5654 configuration to bug-gdb@gnu.org immediately. See the README file for
5655 information about getting a standard C compiler if you don't have one
5660 GDB now uses readline 2.2.
5662 * set extension-language
5664 You can now control the mapping between filename extensions and source
5665 languages by using the `set extension-language' command. For instance,
5666 you can ask GDB to treat .c files as C++ by saying
5667 set extension-language .c c++
5668 The command `info extensions' lists all of the recognized extensions
5669 and their associated languages.
5671 * Setting processor type for PowerPC and RS/6000
5673 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5674 you can use the `set processor' command to specify what variant of the
5675 PowerPC family you are debugging. The command
5679 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5680 following PowerPC and RS6000 variants:
5682 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5683 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5685 403GC IBM PowerPC 403GC
5686 505 Motorola PowerPC 505
5687 860 Motorola PowerPC 860 or 850
5688 601 Motorola PowerPC 601
5689 602 Motorola PowerPC 602
5690 603 Motorola/IBM PowerPC 603 or 603e
5691 604 Motorola PowerPC 604 or 604e
5692 750 Motorola/IBM PowerPC 750 or 750
5694 At the moment, this command just tells GDB what to name the
5695 special-purpose processor registers. Since almost all the affected
5696 registers are inaccessible to user-level programs, this command is
5697 only useful for remote debugging in its present form.
5701 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5702 more extensive support for HP-UX. Added features include shared
5703 library support, kernel threads and hardware watchpoints for 11.00,
5704 support for HP's ANSI C and C++ compilers, and a compatibility mode
5705 for xdb and dbx commands.
5709 HP's donation includes the new concept of catchpoints, which is a
5710 generalization of the old catch command. On HP-UX, it is now possible
5711 to catch exec, fork, and vfork, as well as library loading.
5713 This means that the existing catch command has changed; its first
5714 argument now specifies the type of catch to be set up. See the
5715 output of "help catch" for a list of catchpoint types.
5717 * Debugging across forks
5719 On HP-UX, you can choose which process to debug when a fork() happens
5724 HP has donated a curses-based terminal user interface (TUI). To get
5725 it, build with --enable-tui. Although this can be enabled for any
5726 configuration, at present it only works for native HP debugging.
5728 * GDB remote protocol additions
5730 A new protocol packet 'X' that writes binary data is now available.
5731 Default behavior is to try 'X', then drop back to 'M' if the stub
5732 fails to respond. The settable variable `remotebinarydownload'
5733 allows explicit control over the use of 'X'.
5735 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5736 full 64-bit address. The command
5738 set remoteaddresssize 32
5740 can be used to revert to the old behaviour. For existing remote stubs
5741 the change should not be noticed, as the additional address information
5744 In order to assist in debugging stubs, you may use the maintenance
5745 command `packet' to send any text string to the stub. For instance,
5747 maint packet heythere
5749 sends the packet "$heythere#<checksum>". Note that it is very easy to
5750 disrupt a debugging session by sending the wrong packet at the wrong
5753 The compare-sections command allows you to compare section data on the
5754 target to what is in the executable file without uploading or
5755 downloading, by comparing CRC checksums.
5757 * Tracing can collect general expressions
5759 You may now collect general expressions at tracepoints. This requires
5760 further additions to the target-side stub; see tracepoint.c and
5761 doc/agentexpr.texi for further details.
5763 * mask-address variable for Mips
5765 For Mips targets, you may control the zeroing of the upper 32 bits of
5766 a 64-bit address by entering `set mask-address on'. This is mainly
5767 of interest to users of embedded R4xxx and R5xxx processors.
5769 * Higher serial baud rates
5771 GDB's serial code now allows you to specify baud rates 57600, 115200,
5772 230400, and 460800 baud. (Note that your host system may not be able
5773 to achieve all of these rates.)
5777 The i960 configuration now includes an initial implementation of a
5778 builtin simulator, contributed by Jim Wilson.
5781 *** Changes in GDB-4.17:
5783 * New native configurations
5785 Alpha GNU/Linux alpha*-*-linux*
5786 Unixware 2.x i[3456]86-unixware2*
5787 Irix 6.x mips*-sgi-irix6*
5788 PowerPC GNU/Linux powerpc-*-linux*
5789 PowerPC Solaris powerpcle-*-solaris*
5790 Sparc GNU/Linux sparc-*-linux*
5791 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5795 Argonaut Risc Chip (ARC) arc-*-*
5796 Hitachi H8/300S h8300*-*-*
5797 Matsushita MN10200 w/simulator mn10200-*-*
5798 Matsushita MN10300 w/simulator mn10300-*-*
5799 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5800 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5801 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5802 Mitsubishi D10V w/simulator d10v-*-*
5803 Mitsubishi M32R/D w/simulator m32r-*-elf*
5804 Tsqware Sparclet sparclet-*-*
5805 NEC V850 w/simulator v850-*-*
5807 * New debugging protocols
5809 ARM with RDI protocol arm*-*-*
5810 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5811 DDB and LSI variants of PMON protocol mips*-*-*
5812 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5813 PowerPC with SDS protocol powerpc{,le}-*-eabi
5814 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5818 All configurations can now understand and use the DWARF 2 debugging
5819 format. The choice is automatic, if the symbol file contains DWARF 2
5824 GDB now includes basic Java language support. This support is
5825 only useful with Java compilers that produce native machine code.
5827 * solib-absolute-prefix and solib-search-path
5829 For SunOS and SVR4 shared libraries, you may now set the prefix for
5830 loading absolute shared library symbol files, and the search path for
5831 locating non-absolute shared library symbol files.
5833 * Live range splitting
5835 GDB can now effectively debug code for which GCC has performed live
5836 range splitting as part of its optimization. See gdb/doc/LRS for
5837 more details on the expected format of the stabs information.
5841 GDB's support for the GNU Hurd, including thread debugging, has been
5842 updated to work with current versions of the Hurd.
5846 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5847 instruction set. ARM GDB automatically detects when Thumb
5848 instructions are in use, and adjusts disassembly and backtracing
5853 GDB's MIPS target configurations now handle the MIP16 16-bit
5858 GDB now includes support for overlays; if an executable has been
5859 linked such that multiple sections are based at the same address, GDB
5860 will decide which section to use for symbolic info. You can choose to
5861 control the decision manually, using overlay commands, or implement
5862 additional target-side support and use "overlay load-target" to bring
5863 in the overlay mapping. Do "help overlay" for more detail.
5867 The command "info symbol <address>" displays information about
5868 the symbol at the specified address.
5872 The standard remote protocol now includes an extension that allows
5873 asynchronous collection and display of trace data. This requires
5874 extensive support in the target-side debugging stub. Tracing mode
5875 includes a new interaction mode in GDB and new commands: see the
5876 file tracepoint.c for more details.
5880 Configurations for embedded MIPS now include a simulator contributed
5881 by Cygnus Solutions. The simulator supports the instruction sets
5882 of most MIPS variants.
5886 Sparc configurations may now include the ERC32 simulator contributed
5887 by the European Space Agency. The simulator is not built into
5888 Sparc targets by default; configure with --enable-sim to include it.
5892 For target configurations that may include multiple variants of a
5893 basic architecture (such as MIPS and SH), you may now set the
5894 architecture explicitly. "set arch" sets, "info arch" lists
5895 the possible architectures.
5897 *** Changes in GDB-4.16:
5899 * New native configurations
5901 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5902 M68K NetBSD m68k-*-netbsd*
5903 PowerPC AIX 4.x powerpc-*-aix*
5904 PowerPC MacOS powerpc-*-macos*
5905 PowerPC Windows NT powerpcle-*-cygwin32
5906 RS/6000 AIX 4.x rs6000-*-aix4*
5910 ARM with RDP protocol arm-*-*
5911 I960 with MON960 i960-*-coff
5912 MIPS VxWorks mips*-*-vxworks*
5913 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5914 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5916 Matra Sparclet sparclet-*-*
5920 The powerpc-eabi configuration now includes the PSIM simulator,
5921 contributed by Andrew Cagney, with assistance from Mike Meissner.
5922 PSIM is a very elaborate model of the PowerPC, including not only
5923 basic instruction set execution, but also details of execution unit
5924 performance and I/O hardware. See sim/ppc/README for more details.
5928 GDB now works with Solaris 2.5.
5930 * Windows 95/NT native
5932 GDB will now work as a native debugger on Windows 95 and Windows NT.
5933 To build it from source, you must use the "gnu-win32" environment,
5934 which uses a DLL to emulate enough of Unix to run the GNU tools.
5935 Further information, binaries, and sources are available at
5936 ftp.cygnus.com, under pub/gnu-win32.
5938 * dont-repeat command
5940 If a user-defined command includes the command `dont-repeat', then the
5941 command will not be repeated if the user just types return. This is
5942 useful if the command is time-consuming to run, so that accidental
5943 extra keystrokes don't run the same command many times.
5945 * Send break instead of ^C
5947 The standard remote protocol now includes an option to send a break
5948 rather than a ^C to the target in order to interrupt it. By default,
5949 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5951 * Remote protocol timeout
5953 The standard remote protocol includes a new variable `remotetimeout'
5954 that allows you to set the number of seconds before GDB gives up trying
5955 to read from the target. The default value is 2.
5957 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5959 By default GDB will automatically keep track of objects as they are
5960 loaded and unloaded by the dynamic linker. By using the command `set
5961 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5962 when shared library events occur, thus allowing you to set breakpoints
5963 in shared libraries which are explicitly loaded by the inferior.
5965 Note this feature does not work on hpux8. On hpux9 you must link
5966 /usr/lib/end.o into your program. This feature should work
5967 automatically on hpux10.
5969 * Irix 5.x hardware watchpoint support
5971 Irix 5 configurations now support the use of hardware watchpoints.
5973 * Mips protocol "SYN garbage limit"
5975 When debugging a Mips target using the `target mips' protocol, you
5976 may set the number of characters that GDB will ignore by setting
5977 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5978 every character. The default value is 1050.
5980 * Recording and replaying remote debug sessions
5982 If you set `remotelogfile' to the name of a file, gdb will write to it
5983 a recording of a remote debug session. This recording may then be
5984 replayed back to gdb using "gdbreplay". See gdbserver/README for
5985 details. This is useful when you have a problem with GDB while doing
5986 remote debugging; you can make a recording of the session and send it
5987 to someone else, who can then recreate the problem.
5989 * Speedups for remote debugging
5991 GDB includes speedups for downloading and stepping MIPS systems using
5992 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5993 and more efficient S-record downloading.
5995 * Memory use reductions and statistics collection
5997 GDB now uses less memory and reports statistics about memory usage.
5998 Try the `maint print statistics' command, for example.
6000 *** Changes in GDB-4.15:
6002 * Psymtabs for XCOFF
6004 The symbol reader for AIX GDB now uses partial symbol tables. This
6005 can greatly improve startup time, especially for large executables.
6007 * Remote targets use caching
6009 Remote targets now use a data cache to speed up communication with the
6010 remote side. The data cache could lead to incorrect results because
6011 it doesn't know about volatile variables, thus making it impossible to
6012 debug targets which use memory mapped I/O devices. `set remotecache
6013 off' turns the the data cache off.
6015 * Remote targets may have threads
6017 The standard remote protocol now includes support for multiple threads
6018 in the target system, using new protocol commands 'H' and 'T'. See
6019 gdb/remote.c for details.
6023 If GDB is configured with `--enable-netrom', then it will include
6024 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6025 acts as though it is a bank of ROM on the target board, but you can
6026 write into it over the network. GDB's support consists only of
6027 support for fast loading into the emulated ROM; to debug, you must use
6028 another protocol, such as standard remote protocol. The usual
6029 sequence is something like
6031 target nrom <netrom-hostname>
6033 target remote <netrom-hostname>:1235
6037 GDB now includes support for the Apple Macintosh, as a host only. It
6038 may be run as either an MPW tool or as a standalone application, and
6039 it can debug through the serial port. All the usual GDB commands are
6040 available, but to the target command, you must supply "serial" as the
6041 device type instead of "/dev/ttyXX". See mpw-README in the main
6042 directory for more information on how to build. The MPW configuration
6043 scripts */mpw-config.in support only a few targets, and only the
6044 mips-idt-ecoff target has been tested.
6048 GDB configuration now uses autoconf. This is not user-visible,
6049 but does simplify configuration and building.
6053 GDB now supports hpux10.
6055 *** Changes in GDB-4.14:
6057 * New native configurations
6059 x86 FreeBSD i[345]86-*-freebsd
6060 x86 NetBSD i[345]86-*-netbsd
6061 NS32k NetBSD ns32k-*-netbsd
6062 Sparc NetBSD sparc-*-netbsd
6066 A29K VxWorks a29k-*-vxworks
6067 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6068 CPU32 EST-300 emulator m68*-*-est*
6069 PowerPC ELF powerpc-*-elf
6072 * Alpha OSF/1 support for procfs
6074 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6075 possible to attach to running processes. As the mounting of the /proc
6076 filesystem is optional on the Alpha, GDB automatically determines
6077 the availability of /proc during startup. This can lead to problems
6078 if /proc is unmounted after GDB has been started.
6080 * Arguments to user-defined commands
6082 User commands may accept up to 10 arguments separated by whitespace.
6083 Arguments are accessed within the user command via $arg0..$arg9. A
6086 print $arg0 + $arg1 + $arg2
6088 To execute the command use:
6091 Defines the command "adder" which prints the sum of its three arguments.
6092 Note the arguments are text substitutions, so they may reference variables,
6093 use complex expressions, or even perform inferior function calls.
6095 * New `if' and `while' commands
6097 This makes it possible to write more sophisticated user-defined
6098 commands. Both commands take a single argument, which is the
6099 expression to evaluate, and must be followed by the commands to
6100 execute, one per line, if the expression is nonzero, the list being
6101 terminated by the word `end'. The `if' command list may include an
6102 `else' word, which causes the following commands to be executed only
6103 if the expression is zero.
6105 * Fortran source language mode
6107 GDB now includes partial support for Fortran 77. It will recognize
6108 Fortran programs and can evaluate a subset of Fortran expressions, but
6109 variables and functions may not be handled correctly. GDB will work
6110 with G77, but does not yet know much about symbols emitted by other
6113 * Better HPUX support
6115 Most debugging facilities now work on dynamic executables for HPPAs
6116 running hpux9 or later. You can attach to running dynamically linked
6117 processes, but by default the dynamic libraries will be read-only, so
6118 for instance you won't be able to put breakpoints in them. To change
6119 that behavior do the following before running the program:
6125 This will cause the libraries to be mapped private and read-write.
6126 To revert to the normal behavior, do this:
6132 You cannot set breakpoints or examine data in the library until after
6133 the library is loaded if the function/data symbols do not have
6136 GDB can now also read debug symbols produced by the HP C compiler on
6137 HPPAs (sorry, no C++, Fortran or 68k support).
6139 * Target byte order now dynamically selectable
6141 You can choose which byte order to use with a target system, via the
6142 commands "set endian big" and "set endian little", and you can see the
6143 current setting by using "show endian". You can also give the command
6144 "set endian auto", in which case GDB will use the byte order
6145 associated with the executable. Currently, only embedded MIPS
6146 configurations support dynamic selection of target byte order.
6148 * New DOS host serial code
6150 This version uses DPMI interrupts to handle buffered I/O, so you
6151 no longer need to run asynctsr when debugging boards connected to
6154 *** Changes in GDB-4.13:
6156 * New "complete" command
6158 This lists all the possible completions for the rest of the line, if it
6159 were to be given as a command itself. This is intended for use by emacs.
6161 * Trailing space optional in prompt
6163 "set prompt" no longer adds a space for you after the prompt you set. This
6164 allows you to set a prompt which ends in a space or one that does not.
6166 * Breakpoint hit counts
6168 "info break" now displays a count of the number of times the breakpoint
6169 has been hit. This is especially useful in conjunction with "ignore"; you
6170 can ignore a large number of breakpoint hits, look at the breakpoint info
6171 to see how many times the breakpoint was hit, then run again, ignoring one
6172 less than that number, and this will get you quickly to the last hit of
6175 * Ability to stop printing at NULL character
6177 "set print null-stop" will cause GDB to stop printing the characters of
6178 an array when the first NULL is encountered. This is useful when large
6179 arrays actually contain only short strings.
6181 * Shared library breakpoints
6183 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6184 breakpoints in shared libraries before the executable is run.
6186 * Hardware watchpoints
6188 There is a new hardware breakpoint for the watch command for sparclite
6189 targets. See gdb/sparclite/hw_breakpoint.note.
6191 Hardware watchpoints are also now supported under GNU/Linux.
6195 Annotations have been added. These are for use with graphical interfaces,
6196 and are still experimental. Currently only gdba.el uses these.
6198 * Improved Irix 5 support
6200 GDB now works properly with Irix 5.2.
6202 * Improved HPPA support
6204 GDB now works properly with the latest GCC and GAS.
6206 * New native configurations
6208 Sequent PTX4 i[34]86-sequent-ptx4
6209 HPPA running OSF/1 hppa*-*-osf*
6210 Atari TT running SVR4 m68*-*-sysv4*
6211 RS/6000 LynxOS rs6000-*-lynxos*
6215 OS/9000 i[34]86-*-os9k
6216 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6219 * Hitachi SH7000 and E7000-PC ICE support
6221 There is now support for communicating with the Hitachi E7000-PC ICE.
6222 This is available automatically when GDB is configured for the SH.
6226 As usual, a variety of small fixes and improvements, both generic
6227 and configuration-specific. See the ChangeLog for more detail.
6229 *** Changes in GDB-4.12:
6231 * Irix 5 is now supported
6235 GDB-4.12 on the HPPA has a number of changes which make it unable
6236 to debug the output from the currently released versions of GCC and
6237 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6238 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6239 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6242 *** Changes in GDB-4.11:
6244 * User visible changes:
6248 The "set remotedebug" option is now consistent between the mips remote
6249 target, remote targets using the gdb-specific protocol, UDI (AMD's
6250 debug protocol for the 29k) and the 88k bug monitor. It is now an
6251 integer specifying a debug level (normally 0 or 1, but 2 means more
6252 debugging info for the mips target).
6254 * DEC Alpha native support
6256 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6257 debug info, but GDB works fairly well with the DEC compiler and should
6258 work with a future GCC release. See the README file for a few
6259 Alpha-specific notes.
6261 * Preliminary thread implementation
6263 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6265 * LynxOS native and target support for 386
6267 This release has been hosted on LynxOS 2.2, and also can be configured
6268 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6271 * Improvements in C++ mangling/demangling.
6273 This release has much better g++ debugging, specifically in name
6274 mangling/demangling, virtual function calls, print virtual table,
6275 call methods, ...etc.
6277 *** Changes in GDB-4.10:
6279 * User visible changes:
6281 Remote debugging using the GDB-specific (`target remote') protocol now
6282 supports the `load' command. This is only useful if you have some
6283 other way of getting the stub to the target system, and you can put it
6284 somewhere in memory where it won't get clobbered by the download.
6286 Filename completion now works.
6288 When run under emacs mode, the "info line" command now causes the
6289 arrow to point to the line specified. Also, "info line" prints
6290 addresses in symbolic form (as well as hex).
6292 All vxworks based targets now support a user settable option, called
6293 vxworks-timeout. This option represents the number of seconds gdb
6294 should wait for responses to rpc's. You might want to use this if
6295 your vxworks target is, perhaps, a slow software simulator or happens
6296 to be on the far side of a thin network line.
6300 This release contains support for using a DEC alpha as a GDB host for
6301 cross debugging. Native alpha debugging is not supported yet.
6304 *** Changes in GDB-4.9:
6308 This is the first GDB release which is accompanied by a matching testsuite.
6309 The testsuite requires installation of dejagnu, which should be available
6310 via ftp from most sites that carry GNU software.
6314 'Cfront' style demangling has had its name changed to 'ARM' style, to
6315 emphasize that it was written from the specifications in the C++ Annotated
6316 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6317 disclaimers, it still generated too much confusion with users attempting to
6318 use gdb with AT&T cfront.
6322 GDB now uses a standard remote interface to a simulator library.
6323 So far, the library contains simulators for the Zilog Z8001/2, the
6324 Hitachi H8/300, H8/500 and Super-H.
6326 * New targets supported
6328 H8/300 simulator h8300-hitachi-hms or h8300hms
6329 H8/500 simulator h8500-hitachi-hms or h8500hms
6330 SH simulator sh-hitachi-hms or sh
6331 Z8000 simulator z8k-zilog-none or z8ksim
6332 IDT MIPS board over serial line mips-idt-ecoff
6334 Cross-debugging to GO32 targets is supported. It requires a custom
6335 version of the i386-stub.c module which is integrated with the
6336 GO32 memory extender.
6338 * New remote protocols
6340 MIPS remote debugging protocol.
6342 * New source languages supported
6344 This version includes preliminary support for Chill, a Pascal like language
6345 used by telecommunications companies. Chill support is also being integrated
6346 into the GNU compiler, but we don't know when it will be publically available.
6349 *** Changes in GDB-4.8:
6351 * HP Precision Architecture supported
6353 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6354 version of this support was available as a set of patches from the
6355 University of Utah. GDB does not support debugging of programs
6356 compiled with the HP compiler, because HP will not document their file
6357 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6358 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6360 Many problems in the preliminary version have been fixed.
6362 * Faster and better demangling
6364 We have improved template demangling and fixed numerous bugs in the GNU style
6365 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6366 character types (wchar_t) are now supported. Demangling of each symbol is now
6367 only done once, and is cached when the symbol table for a file is read in.
6368 This results in a small increase in memory usage for C programs, a moderate
6369 increase in memory usage for C++ programs, and a fantastic speedup in
6372 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6373 from the specifications in the Annotated Reference Manual, which AT&T's
6374 compiler does not actually implement.
6376 * G++ multiple inheritance compiler problem
6378 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6379 inheritance lattices was reworked to properly discover ambiguities. We
6380 recently found an example which causes this new algorithm to fail in a
6381 very subtle way, producing bad debug information for those classes.
6382 The file 'gcc.patch' (in this directory) can be applied to gcc to
6383 circumvent the problem. A future GCC release will contain a complete
6386 The previous G++ debug info problem (mentioned below for the gdb-4.7
6387 release) is fixed in gcc version 2.3.2.
6389 * Improved configure script
6391 The `configure' script will now attempt to guess your system type if
6392 you don't supply a host system type. The old scheme of supplying a
6393 host system triplet is preferable over using this. All the magic is
6394 done in the new `config.guess' script. Examine it for details.
6396 We have also brought our configure script much more in line with the FSF's
6397 version. It now supports the --with-xxx options. In particular,
6398 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6399 The resulting GDB will not be able to read arbitrary object file formats --
6400 only the format ``expected'' to be used on the configured target system.
6401 We hope to make this the default in a future release.
6403 * Documentation improvements
6405 There's new internal documentation on how to modify GDB, and how to
6406 produce clean changes to the code. We implore people to read it
6407 before submitting changes.
6409 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6410 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6411 `info' files are also provided. To build `info' files from scratch,
6412 you will need the latest `makeinfo' release, which will be available in
6413 a future texinfo-X.Y release.
6415 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6416 We're not sure exactly which versions have this problem, but it has
6417 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6418 or better. If that isn't possible, there is a patch in
6419 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6420 around this problem.
6424 GDB now supports array constants that can be used in expressions typed in by
6425 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6426 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6429 The new directory `gdb/sparclite' contains a program that demonstrates
6430 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6432 * New native hosts supported
6434 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6435 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6437 * New targets supported
6439 AMD 29k family via UDI a29k-amd-udi or udi29k
6441 * New file formats supported
6443 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6444 HPUX core files, and SCO 3.2v2 core files.
6448 Attaching to processes now works again; thanks for the many bug reports.
6450 We have also stomped on a bunch of core dumps caused by
6451 printf_filtered("%s") problems.
6453 We eliminated a copyright problem on the rpc and ptrace header files
6454 for VxWorks, which was discovered at the last minute during the 4.7
6455 release. You should now be able to build a VxWorks GDB.
6457 You can now interrupt gdb while an attached process is running. This
6458 will cause the attached process to stop, and give control back to GDB.
6460 We fixed problems caused by using too many file descriptors
6461 for reading symbols from object files and libraries. This was
6462 especially a problem for programs that used many (~100) shared
6465 The `step' command now only enters a subroutine if there is line number
6466 information for the subroutine. Otherwise it acts like the `next'
6467 command. Previously, `step' would enter subroutines if there was
6468 any debugging information about the routine. This avoids problems
6469 when using `cc -g1' on MIPS machines.
6471 * Internal improvements
6473 GDB's internal interfaces have been improved to make it easier to support
6474 debugging of multiple languages in the future.
6476 GDB now uses a common structure for symbol information internally.
6477 Minimal symbols (derived from linkage symbols in object files), partial
6478 symbols (from a quick scan of debug information), and full symbols
6479 contain a common subset of information, making it easier to write
6480 shared code that handles any of them.
6482 * New command line options
6484 We now accept --silent as an alias for --quiet.
6488 The memory-mapped-malloc library is now licensed under the GNU Library
6489 General Public License.
6491 *** Changes in GDB-4.7:
6493 * Host/native/target split
6495 GDB has had some major internal surgery to untangle the support for
6496 hosts and remote targets. Now, when you configure GDB for a remote
6497 target, it will no longer load in all of the support for debugging
6498 local programs on the host. When fully completed and tested, this will
6499 ensure that arbitrary host/target combinations are possible.
6501 The primary conceptual shift is to separate the non-portable code in
6502 GDB into three categories. Host specific code is required any time GDB
6503 is compiled on that host, regardless of the target. Target specific
6504 code relates to the peculiarities of the target, but can be compiled on
6505 any host. Native specific code is everything else: it can only be
6506 built when the host and target are the same system. Child process
6507 handling and core file support are two common `native' examples.
6509 GDB's use of /proc for controlling Unix child processes is now cleaner.
6510 It has been split out into a single module under the `target_ops' vector,
6511 plus two native-dependent functions for each system that uses /proc.
6513 * New hosts supported
6515 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6516 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6517 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6519 * New targets supported
6521 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6522 68030 and CPU32 m68030-*-*, m68332-*-*
6524 * New native hosts supported
6526 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6527 (386bsd is not well tested yet)
6528 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6530 * New file formats supported
6532 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6533 supports reading of `a.out.adobe' object files, which are an a.out
6534 format extended with minimal information about multiple sections.
6538 `show copying' is the same as the old `info copying'.
6539 `show warranty' is the same as `info warrantee'.
6540 These were renamed for consistency. The old commands continue to work.
6542 `info handle' is a new alias for `info signals'.
6544 You can now define pre-command hooks, which attach arbitrary command
6545 scripts to any command. The commands in the hook will be executed
6546 prior to the user's command. You can also create a hook which will be
6547 executed whenever the program stops. See gdb.texinfo.
6551 We now deal with Cfront style name mangling, and can even extract type
6552 info from mangled symbols. GDB can automatically figure out which
6553 symbol mangling style your C++ compiler uses.
6555 Calling of methods and virtual functions has been improved as well.
6559 The crash that occured when debugging Sun Ansi-C compiled binaries is
6560 fixed. This was due to mishandling of the extra N_SO stabs output
6563 We also finally got Ultrix 4.2 running in house, and fixed core file
6564 support, with help from a dozen people on the net.
6566 John M. Farrell discovered that the reason that single-stepping was so
6567 slow on all of the Mips based platforms (primarily SGI and DEC) was
6568 that we were trying to demangle and lookup a symbol used for internal
6569 purposes on every instruction that was being stepped through. Changing
6570 the name of that symbol so that it couldn't be mistaken for a C++
6571 mangled symbol sped things up a great deal.
6573 Rich Pixley sped up symbol lookups in general by getting much smarter
6574 about when C++ symbol mangling is necessary. This should make symbol
6575 completion (TAB on the command line) much faster. It's not as fast as
6576 we'd like, but it's significantly faster than gdb-4.6.
6580 A new user controllable variable 'call_scratch_address' can
6581 specify the location of a scratch area to be used when GDB
6582 calls a function in the target. This is necessary because the
6583 usual method of putting the scratch area on the stack does not work
6584 in systems that have separate instruction and data spaces.
6586 We integrated changes to support the 29k UDI (Universal Debugger
6587 Interface), but discovered at the last minute that we didn't have all
6588 of the appropriate copyright paperwork. We are working with AMD to
6589 resolve this, and hope to have it available soon.
6593 We have sped up the remote serial line protocol, especially for targets
6594 with lots of registers. It now supports a new `expedited status' ('T')
6595 message which can be used in place of the existing 'S' status message.
6596 This allows the remote stub to send only the registers that GDB
6597 needs to make a quick decision about single-stepping or conditional
6598 breakpoints, eliminating the need to fetch the entire register set for
6599 each instruction being stepped through.
6601 The GDB remote serial protocol now implements a write-through cache for
6602 registers, only re-reading the registers if the target has run.
6604 There is also a new remote serial stub for SPARC processors. You can
6605 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6606 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6607 processor with a serial port.
6611 Configure.in files have become much easier to read and modify. A new
6612 `table driven' format makes it more obvious what configurations are
6613 supported, and what files each one uses.
6617 There is a new opcodes library which will eventually contain all of the
6618 disassembly routines and opcode tables. At present, it only contains
6619 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6620 disassembler (binutils/objdump) to share these routines.
6622 The libiberty library is now copylefted under the GNU Library General
6623 Public License. This allows more liberal use, and was done so libg++
6624 can use it. This makes no difference to GDB, since the Library License
6625 grants all the rights from the General Public License.
6629 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6630 reference to the stabs symbol info used by the debugger. It is (as far
6631 as we know) the only published document on this fascinating topic. We
6632 encourage you to read it, compare it to the stabs information on your
6633 system, and send improvements on the document in general (to
6634 bug-gdb@prep.ai.mit.edu).
6636 And, of course, many bugs have been fixed.
6639 *** Changes in GDB-4.6:
6641 * Better support for C++ function names
6643 GDB now accepts as input the "demangled form" of C++ overloaded function
6644 names and member function names, and can do command completion on such names
6645 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6646 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6647 Make use of command completion, it is your friend.
6649 GDB also now accepts a variety of C++ mangled symbol formats. They are
6650 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6651 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6652 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6653 for the list of formats.
6655 * G++ symbol mangling problem
6657 Recent versions of gcc have a bug in how they emit debugging information for
6658 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6659 directory) can be applied to gcc to fix the problem. Alternatively, if you
6660 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6661 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6662 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6665 * New 'maintenance' command
6667 All of the commands related to hacking GDB internals have been moved out of
6668 the main command set, and now live behind the 'maintenance' command. This
6669 can also be abbreviated as 'mt'. The following changes were made:
6671 dump-me -> maintenance dump-me
6672 info all-breakpoints -> maintenance info breakpoints
6673 printmsyms -> maintenance print msyms
6674 printobjfiles -> maintenance print objfiles
6675 printpsyms -> maintenance print psymbols
6676 printsyms -> maintenance print symbols
6678 The following commands are new:
6680 maintenance demangle Call internal GDB demangler routine to
6681 demangle a C++ link name and prints the result.
6682 maintenance print type Print a type chain for a given symbol
6684 * Change to .gdbinit file processing
6686 We now read the $HOME/.gdbinit file before processing the argv arguments
6687 (e.g. reading symbol files or core files). This allows global parameters to
6688 be set, which will apply during the symbol reading. The ./.gdbinit is still
6689 read after argv processing.
6691 * New hosts supported
6693 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6695 GNU/Linux support i386-unknown-linux or linux
6697 We are also including code to support the HP/PA running BSD and HPUX. This
6698 is almost guaranteed not to work, as we didn't have time to test or build it
6699 for this release. We are including it so that the more adventurous (or
6700 masochistic) of you can play with it. We also had major problems with the
6701 fact that the compiler that we got from HP doesn't support the -g option.
6704 * New targets supported
6706 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6708 * More smarts about finding #include files
6710 GDB now remembers the compilation directory for all include files, and for
6711 all files from which C is generated (like yacc and lex sources). This
6712 greatly improves GDB's ability to find yacc/lex sources, and include files,
6713 especially if you are debugging your program from a directory different from
6714 the one that contains your sources.
6716 We also fixed a bug which caused difficulty with listing and setting
6717 breakpoints in include files which contain C code. (In the past, you had to
6718 try twice in order to list an include file that you hadn't looked at before.)
6720 * Interesting infernals change
6722 GDB now deals with arbitrary numbers of sections, where the symbols for each
6723 section must be relocated relative to that section's landing place in the
6724 target's address space. This work was needed to support ELF with embedded
6725 stabs used by Solaris-2.0.
6727 * Bug fixes (of course!)
6729 There have been loads of fixes for the following things:
6730 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6731 i960, stabs, DOS(GO32), procfs, etc...
6733 See the ChangeLog for details.
6735 *** Changes in GDB-4.5:
6737 * New machines supported (host and target)
6739 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6741 SGI Irix-4.x mips-sgi-irix4 or iris4
6743 * New malloc package
6745 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6746 Mmalloc is capable of handling mutiple heaps of memory. It is also
6747 capable of saving a heap to a file, and then mapping it back in later.
6748 This can be used to greatly speedup the startup of GDB by using a
6749 pre-parsed symbol table which lives in a mmalloc managed heap. For
6750 more details, please read mmalloc/mmalloc.texi.
6754 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6755 'help info proc' for details.
6757 * MIPS ecoff symbol table format
6759 The code that reads MIPS symbol table format is now supported on all hosts.
6760 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6763 * File name changes for MS-DOS
6765 Many files in the config directories have been renamed to make it easier to
6766 support GDB on MS-DOSe systems (which have very restrictive file name
6767 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6768 environment) is close to working but has some remaining problems. Note
6769 that debugging of DOS programs is not supported, due to limitations
6770 in the ``operating system'', but it can be used to host cross-debugging.
6772 * Cross byte order fixes
6774 Many fixes have been made to support cross debugging of Sparc and MIPS
6775 targets from hosts whose byte order differs.
6777 * New -mapped and -readnow options
6779 If memory-mapped files are available on your system through the 'mmap'
6780 system call, you can use the -mapped option on the `file' or
6781 `symbol-file' commands to cause GDB to write the symbols from your
6782 program into a reusable file. If the program you are debugging is
6783 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6784 Future GDB debugging sessions will notice the presence of this file,
6785 and will quickly map in symbol information from it, rather than reading
6786 the symbol table from the executable program. Using the '-mapped'
6787 option in a GDB `file' or `symbol-file' command has the same effect as
6788 starting GDB with the '-mapped' command-line option.
6790 You can cause GDB to read the entire symbol table immediately by using
6791 the '-readnow' option with any of the commands that load symbol table
6792 information (or on the GDB command line). This makes the command
6793 slower, but makes future operations faster.
6795 The -mapped and -readnow options are typically combined in order to
6796 build a `fred.syms' file that contains complete symbol information.
6797 A simple GDB invocation to do nothing but build a `.syms' file for future
6800 gdb -batch -nx -mapped -readnow programname
6802 The `.syms' file is specific to the host machine on which GDB is run.
6803 It holds an exact image of GDB's internal symbol table. It cannot be
6804 shared across multiple host platforms.
6806 * longjmp() handling
6808 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6809 siglongjmp() without losing control. This feature has not yet been ported to
6810 all systems. It currently works on many 386 platforms, all MIPS-based
6811 platforms (SGI, DECstation, etc), and Sun3/4.
6815 Preliminary work has been put in to support the new Solaris OS from Sun. At
6816 this time, it can control and debug processes, but it is not capable of
6821 As always, many many bug fixes. The major areas were with g++, and mipsread.
6822 People using the MIPS-based platforms should experience fewer mysterious
6823 crashes and trashed symbol tables.
6825 *** Changes in GDB-4.4:
6827 * New machines supported (host and target)
6829 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6831 BSD Reno on Vax vax-dec-bsd
6832 Ultrix on Vax vax-dec-ultrix
6834 * New machines supported (target)
6836 AMD 29000 embedded, using EBMON a29k-none-none
6840 GDB continues to improve its handling of C++. `References' work better.
6841 The demangler has also been improved, and now deals with symbols mangled as
6842 per the Annotated C++ Reference Guide.
6844 GDB also now handles `stabs' symbol information embedded in MIPS
6845 `ecoff' symbol tables. Since the ecoff format was not easily
6846 extensible to handle new languages such as C++, this appeared to be a
6847 good way to put C++ debugging info into MIPS binaries. This option
6848 will be supported in the GNU C compiler, version 2, when it is
6851 * New features for SVR4
6853 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6854 shared libraries. Debugging dynamically linked programs should present
6855 only minor differences from debugging statically linked programs.
6857 The `info proc' command will print out information about any process
6858 on an SVR4 system (including the one you are debugging). At the moment,
6859 it prints the address mappings of the process.
6861 If you bring up GDB on another SVR4 system, please send mail to
6862 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6864 * Better dynamic linking support in SunOS
6866 Reading symbols from shared libraries which contain debugging symbols
6867 now works properly. However, there remain issues such as automatic
6868 skipping of `transfer vector' code during function calls, which
6869 make it harder to debug code in a shared library, than to debug the
6870 same code linked statically.
6874 GDB is now using the latest `getopt' routines from the FSF. This
6875 version accepts the -- prefix for options with long names. GDB will
6876 continue to accept the old forms (-option and +option) as well.
6877 Various single letter abbreviations for options have been explicity
6878 added to the option table so that they won't get overshadowed in the
6879 future by other options that begin with the same letter.
6883 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6884 Many assorted bugs have been handled. Many more remain to be handled.
6885 See the various ChangeLog files (primarily in gdb and bfd) for details.
6888 *** Changes in GDB-4.3:
6890 * New machines supported (host and target)
6892 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6893 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6894 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6896 * Almost SCO Unix support
6898 We had hoped to support:
6899 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6900 (except for core file support), but we discovered very late in the release
6901 that it has problems with process groups that render gdb unusable. Sorry
6902 about that. I encourage people to fix it and post the fixes.
6904 * Preliminary ELF and DWARF support
6906 GDB can read ELF object files on System V Release 4, and can handle
6907 debugging records for C, in DWARF format, in ELF files. This support
6908 is preliminary. If you bring up GDB on another SVR4 system, please
6909 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6914 GDB now uses the latest `readline' library. One user-visible change
6915 is that two tabs will list possible command completions, which previously
6916 required typing M-? (meta-question mark, or ESC ?).
6920 The `stepi' bug that many of you noticed has been squashed.
6921 Many bugs in C++ have been handled. Many more remain to be handled.
6922 See the various ChangeLog files (primarily in gdb and bfd) for details.
6924 * State of the MIPS world (in case you wondered):
6926 GDB can understand the symbol tables emitted by the compilers
6927 supplied by most vendors of MIPS-based machines, including DEC. These
6928 symbol tables are in a format that essentially nobody else uses.
6930 Some versions of gcc come with an assembler post-processor called
6931 mips-tfile. This program is required if you want to do source-level
6932 debugging of gcc-compiled programs. I believe FSF does not ship
6933 mips-tfile with gcc version 1, but it will eventually come with gcc
6936 Debugging of g++ output remains a problem. g++ version 1.xx does not
6937 really support it at all. (If you're lucky, you should be able to get
6938 line numbers and stack traces to work, but no parameters or local
6939 variables.) With some work it should be possible to improve the
6942 When gcc version 2 is released, you will have somewhat better luck.
6943 However, even then you will get confusing results for inheritance and
6946 We will eventually provide full debugging of g++ output on
6947 DECstations. This will probably involve some kind of stabs-in-ecoff
6948 encapulation, but the details have not been worked out yet.
6951 *** Changes in GDB-4.2:
6953 * Improved configuration
6955 Only one copy of `configure' exists now, and it is not self-modifying.
6956 Porting BFD is simpler.
6960 The `step' and `next' commands now only stop at the first instruction
6961 of a source line. This prevents the multiple stops that used to occur
6962 in switch statements, for-loops, etc. `Step' continues to stop if a
6963 function that has debugging information is called within the line.
6967 Lots of small bugs fixed. More remain.
6969 * New host supported (not target)
6971 Intel 386 PC clone running Mach i386-none-mach
6974 *** Changes in GDB-4.1:
6976 * Multiple source language support
6978 GDB now has internal scaffolding to handle several source languages.
6979 It determines the type of each source file from its filename extension,
6980 and will switch expression parsing and number formatting to match the
6981 language of the function in the currently selected stack frame.
6982 You can also specifically set the language to be used, with
6983 `set language c' or `set language modula-2'.
6987 GDB now has preliminary support for the GNU Modula-2 compiler,
6988 currently under development at the State University of New York at
6989 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6990 continue through the fall of 1991 and into 1992.
6992 Other Modula-2 compilers are currently not supported, and attempting to
6993 debug programs compiled with them will likely result in an error as the
6994 symbol table is read. Feel free to work on it, though!
6996 There are hooks in GDB for strict type checking and range checking,
6997 in the `Modula-2 philosophy', but they do not currently work.
7001 GDB can now write to executable and core files (e.g. patch
7002 a variable's value). You must turn this switch on, specify
7003 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7004 by assigning a new value to a variable. Modifications take
7007 * Automatic SunOS shared library reading
7009 When you run your program, GDB automatically determines where its
7010 shared libraries (if any) have been loaded, and reads their symbols.
7011 The `share' command is no longer needed. This also works when
7012 examining core files.
7016 You can specify the number of lines that the `list' command shows.
7019 * New machines supported (host and target)
7021 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7022 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7023 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7025 * New hosts supported (not targets)
7027 IBM RT/PC: romp-ibm-aix or rtpc
7029 * New targets supported (not hosts)
7031 AMD 29000 embedded with COFF a29k-none-coff
7032 AMD 29000 embedded with a.out a29k-none-aout
7033 Ultracomputer remote kernel debug a29k-nyu-kern
7035 * New remote interfaces
7041 *** Changes in GDB-4.0:
7045 Wide output is wrapped at good places to make the output more readable.
7047 Gdb now supports cross-debugging from a host machine of one type to a
7048 target machine of another type. Communication with the target system
7049 is over serial lines. The ``target'' command handles connecting to the
7050 remote system; the ``load'' command will download a program into the
7051 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7052 also supports debugging of realtime processes running under VxWorks,
7053 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7054 stub on the target system.
7056 New CPUs supported include the AMD 29000 and Intel 960.
7058 GDB now reads object files and symbol tables via a ``binary file''
7059 library, which allows a single copy of GDB to debug programs of multiple
7060 object file types such as a.out and coff.
7062 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7063 refcard.dvi and refcard.ps are available to format it).
7066 * Control-Variable user interface simplified
7068 All variables that control the operation of the debugger can be set
7069 by the ``set'' command, and displayed by the ``show'' command.
7071 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7072 ``Show prompt'' produces the response:
7073 Gdb's prompt is new-gdb=>.
7075 What follows are the NEW set commands. The command ``help set'' will
7076 print a complete list of old and new set commands. ``help set FOO''
7077 will give a longer description of the variable FOO. ``show'' will show
7078 all of the variable descriptions and their current settings.
7080 confirm on/off: Enables warning questions for operations that are
7081 hard to recover from, e.g. rerunning the program while
7082 it is already running. Default is ON.
7084 editing on/off: Enables EMACS style command line editing
7085 of input. Previous lines can be recalled with
7086 control-P, the current line can be edited with control-B,
7087 you can search for commands with control-R, etc.
7090 history filename NAME: NAME is where the gdb command history
7091 will be stored. The default is .gdb_history,
7092 or the value of the environment variable
7095 history size N: The size, in commands, of the command history. The
7096 default is 256, or the value of the environment variable
7099 history save on/off: If this value is set to ON, the history file will
7100 be saved after exiting gdb. If set to OFF, the
7101 file will not be saved. The default is OFF.
7103 history expansion on/off: If this value is set to ON, then csh-like
7104 history expansion will be performed on
7105 command line input. The default is OFF.
7107 radix N: Sets the default radix for input and output. It can be set
7108 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7109 in the current radix, so "set radix 10" is always a no-op.
7111 height N: This integer value is the number of lines on a page. Default
7112 is 24, the current `stty rows'' setting, or the ``li#''
7113 setting from the termcap entry matching the environment
7116 width N: This integer value is the number of characters on a line.
7117 Default is 80, the current `stty cols'' setting, or the ``co#''
7118 setting from the termcap entry matching the environment
7121 Note: ``set screensize'' is obsolete. Use ``set height'' and
7122 ``set width'' instead.
7124 print address on/off: Print memory addresses in various command displays,
7125 such as stack traces and structure values. Gdb looks
7126 more ``symbolic'' if you turn this off; it looks more
7127 ``machine level'' with it on. Default is ON.
7129 print array on/off: Prettyprint arrays. New convenient format! Default
7132 print demangle on/off: Print C++ symbols in "source" form if on,
7135 print asm-demangle on/off: Same, for assembler level printouts
7138 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7141 * Support for Epoch Environment.
7143 The epoch environment is a version of Emacs v18 with windowing. One
7144 new command, ``inspect'', is identical to ``print'', except that if you
7145 are running in the epoch environment, the value is printed in its own
7149 * Support for Shared Libraries
7151 GDB can now debug programs and core files that use SunOS shared libraries.
7152 Symbols from a shared library cannot be referenced
7153 before the shared library has been linked with the program (this
7154 happens after you type ``run'' and before the function main() is entered).
7155 At any time after this linking (including when examining core files
7156 from dynamically linked programs), gdb reads the symbols from each
7157 shared library when you type the ``sharedlibrary'' command.
7158 It can be abbreviated ``share''.
7160 sharedlibrary REGEXP: Load shared object library symbols for files
7161 matching a unix regular expression. No argument
7162 indicates to load symbols for all shared libraries.
7164 info sharedlibrary: Status of loaded shared libraries.
7169 A watchpoint stops execution of a program whenever the value of an
7170 expression changes. Checking for this slows down execution
7171 tremendously whenever you are in the scope of the expression, but is
7172 quite useful for catching tough ``bit-spreader'' or pointer misuse
7173 problems. Some machines such as the 386 have hardware for doing this
7174 more quickly, and future versions of gdb will use this hardware.
7176 watch EXP: Set a watchpoint (breakpoint) for an expression.
7178 info watchpoints: Information about your watchpoints.
7180 delete N: Deletes watchpoint number N (same as breakpoints).
7181 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7182 enable N: Re-enables watchpoint number N (same as breakpoints).
7185 * C++ multiple inheritance
7187 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7190 * C++ exception handling
7192 Gdb now supports limited C++ exception handling. Besides the existing
7193 ability to breakpoint on an exception handler, gdb can breakpoint on
7194 the raising of an exception (before the stack is peeled back to the
7197 catch FOO: If there is a FOO exception handler in the dynamic scope,
7198 set a breakpoint to catch exceptions which may be raised there.
7199 Multiple exceptions (``catch foo bar baz'') may be caught.
7201 info catch: Lists all exceptions which may be caught in the
7202 current stack frame.
7205 * Minor command changes
7207 The command ``call func (arg, arg, ...)'' now acts like the print
7208 command, except it does not print or save a value if the function's result
7209 is void. This is similar to dbx usage.
7211 The ``up'' and ``down'' commands now always print the frame they end up
7212 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7213 frames without printing.
7215 * New directory command
7217 'dir' now adds directories to the FRONT of the source search path.
7218 The path starts off empty. Source files that contain debug information
7219 about the directory in which they were compiled can be found even
7220 with an empty path; Sun CC and GCC include this information. If GDB can't
7221 find your source file in the current directory, type "dir .".
7223 * Configuring GDB for compilation
7225 For normal use, type ``./configure host''. See README or gdb.texinfo
7228 GDB now handles cross debugging. If you are remotely debugging between
7229 two different machines, type ``./configure host -target=targ''.
7230 Host is the machine where GDB will run; targ is the machine
7231 where the program that you are debugging will run.