1 What has changed in GDB?
2 (Organized release by release)
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 * The RISC-V target now supports target descriptions.
35 * System call catchpoints now support system call aliases on FreeBSD.
36 When the ABI of a system call changes in FreeBSD, this is
37 implemented by leaving a compatibility system call using the old ABI
38 at the existing number and allocating a new system call number for
39 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
40 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
41 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
42 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
43 so that a system call catchpoint for the 'kevent' system call will
44 catch invocations of both the 'kevent' and 'freebsd11_kevent'
45 binaries. This ensures that 'kevent' system calls are caught for
46 binaries using either the old or new ABIs.
48 * Terminal styling is now available for the CLI and the TUI. GNU
49 Source Highlight can additionally be used to provide styling of
50 source code snippets. See the "set style" commands, below, for more
53 * Removed support for old demangling styles arm, edg, gnu, hp and
58 set debug compile-cplus-types
59 show debug compile-cplus-types
60 Control the display of debug output about type conversion in the
61 C++ compile feature. Commands have no effect while compiliong
66 Control whether debug output about files/functions skipping is
69 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
70 Apply a command to some frames.
71 FLAG arguments allow to control what output to produce and how to handle
72 errors raised when applying COMMAND to a frame.
75 Apply a command to all threads (ignoring errors and empty output).
76 Shortcut for 'thread apply all -s COMMAND'.
79 Apply a command to all frames (ignoring errors and empty output).
80 Shortcut for 'frame apply all -s COMMAND'.
83 Apply a command to all frames of all threads (ignoring errors and empty
85 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
87 maint set dwarf unwinders (on|off)
88 maint show dwarf unwinders
89 Control whether DWARF unwinders can be used.
92 Display a list of open files for a process.
96 Changes to the "frame", "select-frame", and "info frame" CLI commands.
97 These commands all now take a frame specification which
98 is either a frame level, or one of the keywords 'level', 'address',
99 'function', or 'view' followed by a parameter. Selecting a frame by
100 address, or viewing a frame outside the current backtrace now
101 requires the use of a keyword. Selecting a frame by level is
102 unchanged. The MI comment "-stack-select-frame" is unchanged.
104 target remote FILENAME
105 target extended-remote FILENAME
106 If FILENAME is a Unix domain socket, GDB will attempt to connect
107 to this socket instead of opening FILENAME as a character device.
109 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
110 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
111 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
112 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
113 These commands can now print only the searched entities
114 matching the provided regexp(s), giving a condition
115 on the entity names or entity types. The flag -q disables
116 printing headers or informations messages.
122 These commands now determine the syntax for the shown entities
123 according to the language chosen by `set language'. In particular,
124 `set language auto' means to automatically choose the language of
127 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
128 The 'thread apply' command accepts new FLAG arguments.
129 FLAG arguments allow to control what output to produce and how to handle
130 errors raised when applying COMMAND to a thread.
132 set tui tab-width NCHARS
133 show tui tab-width NCHARS
134 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
136 set style enabled [on|off]
138 Enable or disable terminal styling. Styling is enabled by default
139 on most hosts, but disabled by default when in batch mode.
141 set style sources [on|off]
143 Enable or disable source code styling. Source code styling is
144 enabled by default, but only takes effect if styling in general is
145 enabled, and if GDB was linked with GNU Source Highlight.
147 set style filename foreground COLOR
148 set style filename background COLOR
149 set style filename intensity VALUE
150 Control the styling of file names.
152 set style function foreground COLOR
153 set style function background COLOR
154 set style function intensity VALUE
155 Control the styling of function names.
157 set style variable foreground COLOR
158 set style variable background COLOR
159 set style variable intensity VALUE
160 Control the styling of variable names.
162 set style address foreground COLOR
163 set style address background COLOR
164 set style address intensity VALUE
165 Control the styling of addresses.
169 ** The '-data-disassemble' MI command now accepts an '-a' option to
170 disassemble the whole function surrounding the given program
171 counter value or function name. Support for this feature can be
172 verified by using the "-list-features" command, which should
173 contain "data-disassemble-a-option".
175 ** Command responses and notifications that include a frame now include
176 the frame's architecture in a new "arch" attribute.
178 * New native configurations
180 GNU/Linux/RISC-V riscv*-*-linux*
181 FreeBSD/riscv riscv*-*-freebsd*
185 GNU/Linux/RISC-V riscv*-*-linux*
187 CSKY GNU/LINUX csky*-*-linux
188 FreeBSD/riscv riscv*-*-freebsd*
190 GNU/Linux/OpenRISC or1k*-*-linux*
194 GDB no longer supports native debugging on versions of MS-Windows
199 ** GDB no longer supports Python versions less than 2.6.
201 ** The gdb.Inferior type has a new 'progspace' property, which is the program
202 space associated to that inferior.
204 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
205 of objfiles associated to that program space.
207 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
208 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
211 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
212 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
213 correct and did not work properly.
215 ** The gdb.Value type has a new constructor, which is used to construct a
216 gdb.Value from a Python buffer object and a gdb.Type.
222 Enable or disable the undefined behavior sanitizer. This is
223 disabled by default, but passing --enable-ubsan=yes or
224 --enable-ubsan=auto to configure will enable it. Enabling this can
225 cause a performance penalty. The undefined behavior sanitizer was
226 first introduced in GCC 4.9.
228 *** Changes in GDB 8.2
230 * The 'set disassembler-options' command now supports specifying options
233 * The 'symbol-file' command now accepts an '-o' option to add a relative
234 offset to all sections.
236 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
237 a relative offset to all sections, but it allows to override the load
238 address of individual sections using '-s'.
240 * The 'add-symbol-file' command no longer requires the second argument
241 (address of the text section).
243 * The endianness used with the 'set endian auto' mode in the absence of
244 an executable selected for debugging is now the last endianness chosen
245 either by one of the 'set endian big' and 'set endian little' commands
246 or by inferring from the last executable used, rather than the startup
249 * The pager now allows a "c" response, meaning to disable the pager
250 for the rest of the current command.
252 * The commands 'info variables/functions/types' now show the source line
253 numbers of symbol definitions when available.
255 * 'info proc' now works on running processes on FreeBSD systems and core
256 files created on FreeBSD systems.
258 * C expressions can now use _Alignof, and C++ expressions can now use
261 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
262 the vector length while the process is running.
268 Control display of debugging info regarding the FreeBSD native target.
270 set|show varsize-limit
271 This new setting allows the user to control the maximum size of Ada
272 objects being printed when those objects have a variable type,
273 instead of that maximum size being hardcoded to 65536 bytes.
275 set|show record btrace cpu
276 Controls the processor to be used for enabling errata workarounds for
279 maint check libthread-db
280 Run integrity checks on the current inferior's thread debugging
283 maint set check-libthread-db (on|off)
284 maint show check-libthread-db
285 Control whether to run integrity checks on inferior specific thread
286 debugging libraries as they are loaded. The default is not to
291 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
293 ** The commands attached to a breakpoint can be set by assigning to
294 the breakpoint's "commands" field.
296 ** gdb.execute can now execute multi-line gdb commands.
298 ** The new functions gdb.convenience_variable and
299 gdb.set_convenience_variable can be used to get and set the value
300 of convenience variables.
302 ** A gdb.Parameter will no longer print the "set" help text on an
303 ordinary "set"; instead by default a "set" will be silent unless
304 the get_set_string method returns a non-empty string.
308 RiscV ELF riscv*-*-elf
310 * Removed targets and native configurations
312 m88k running OpenBSD m88*-*-openbsd*
313 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
314 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
315 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
317 * Aarch64/Linux hardware watchpoints improvements
319 Hardware watchpoints on unaligned addresses are now properly
320 supported when running Linux kernel 4.10 or higher: read and access
321 watchpoints are no longer spuriously missed, and all watchpoints
322 lengths between 1 and 8 bytes are supported. On older kernels,
323 watchpoints set on unaligned addresses are no longer missed, with
324 the tradeoff that there is a possibility of false hits being
329 --enable-codesign=CERT
330 This can be used to invoke "codesign -s CERT" after building gdb.
331 This option is useful on macOS, where code signing is required for
332 gdb to work properly.
334 --disable-gdbcli has been removed
335 This is now silently accepted, but does nothing.
337 *** Changes in GDB 8.1
339 * GDB now supports dynamically creating arbitrary register groups specified
340 in XML target descriptions. This allows for finer grain grouping of
341 registers on systems with a large amount of registers.
343 * The 'ptype' command now accepts a '/o' flag, which prints the
344 offsets and sizes of fields in a struct, like the pahole(1) tool.
346 * New "--readnever" command line option instructs GDB to not read each
347 symbol file's symbolic debug information. This makes startup faster
348 but at the expense of not being able to perform symbolic debugging.
349 This option is intended for use cases where symbolic debugging will
350 not be used, e.g., when you only need to dump the debuggee's core.
352 * GDB now uses the GNU MPFR library, if available, to emulate target
353 floating-point arithmetic during expression evaluation when the target
354 uses different floating-point formats than the host. At least version
355 3.1 of GNU MPFR is required.
357 * GDB now supports access to the guarded-storage-control registers and the
358 software-based guarded-storage broadcast control registers on IBM z14.
360 * On Unix systems, GDB now supports transmitting environment variables
361 that are to be set or unset to GDBserver. These variables will
362 affect the environment to be passed to the remote inferior.
364 To inform GDB of environment variables that are to be transmitted to
365 GDBserver, use the "set environment" command. Only user set
366 environment variables are sent to GDBserver.
368 To inform GDB of environment variables that are to be unset before
369 the remote inferior is started by the GDBserver, use the "unset
370 environment" command.
372 * Completion improvements
374 ** GDB can now complete function parameters in linespecs and
375 explicit locations without quoting. When setting breakpoints,
376 quoting around functions names to help with TAB-completion is
377 generally no longer necessary. For example, this now completes
380 (gdb) b function(in[TAB]
381 (gdb) b function(int)
383 Related, GDB is no longer confused with completing functions in
384 C++ anonymous namespaces:
387 (gdb) b (anonymous namespace)::[TAB][TAB]
388 (anonymous namespace)::a_function()
389 (anonymous namespace)::b_function()
391 ** GDB now has much improved linespec and explicit locations TAB
392 completion support, that better understands what you're
393 completing and offers better suggestions. For example, GDB no
394 longer offers data symbols as possible completions when you're
395 setting a breakpoint.
397 ** GDB now TAB-completes label symbol names.
399 ** The "complete" command now mimics TAB completion accurately.
401 * New command line options (gcore)
404 Dump all memory mappings.
406 * Breakpoints on C++ functions are now set on all scopes by default
408 By default, breakpoints on functions/methods are now interpreted as
409 specifying all functions with the given name ignoring missing
410 leading scopes (namespaces and classes).
412 For example, assuming a C++ program with symbols named:
417 both commands "break func()" and "break B::func()" set a breakpoint
420 You can use the new flag "-qualified" to override this. This makes
421 GDB interpret the specified function name as a complete
422 fully-qualified name instead. For example, using the same C++
423 program, the "break -q B::func" command sets a breakpoint on
424 "B::func", only. A parameter has been added to the Python
425 gdb.Breakpoint constructor to achieve the same result when creating
426 a breakpoint from Python.
428 * Breakpoints on functions marked with C++ ABI tags
430 GDB can now set breakpoints on functions marked with C++ ABI tags
431 (e.g., [abi:cxx11]). See here for a description of ABI tags:
432 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
434 Functions with a C++11 abi tag are demangled/displayed like this:
436 function[abi:cxx11](int)
439 You can now set a breakpoint on such functions simply as if they had
442 (gdb) b function(int)
444 Or if you need to disambiguate between tags, like:
446 (gdb) b function[abi:other_tag](int)
448 Tab completion was adjusted accordingly as well.
452 ** New events gdb.new_inferior, gdb.inferior_deleted, and
453 gdb.new_thread are emitted. See the manual for further
454 description of these.
456 ** A new function, "gdb.rbreak" has been added to the Python API.
457 This function allows the setting of a large number of breakpoints
458 via a regex pattern in Python. See the manual for further details.
460 ** Python breakpoints can now accept explicit locations. See the
461 manual for a further description of this feature.
464 * New features in the GDB remote stub, GDBserver
466 ** GDBserver is now able to start inferior processes with a
467 specified initial working directory.
469 The user can set the desired working directory to be used from
470 GDB using the new "set cwd" command.
472 ** New "--selftest" command line option runs some GDBserver self
473 tests. These self tests are disabled in releases.
475 ** On Unix systems, GDBserver now does globbing expansion and variable
476 substitution in inferior command line arguments.
478 This is done by starting inferiors using a shell, like GDB does.
479 See "set startup-with-shell" in the user manual for how to disable
480 this from GDB when using "target extended-remote". When using
481 "target remote", you can disable the startup with shell by using the
482 new "--no-startup-with-shell" GDBserver command line option.
484 ** On Unix systems, GDBserver now supports receiving environment
485 variables that are to be set or unset from GDB. These variables
486 will affect the environment to be passed to the inferior.
488 * When catching an Ada exception raised with a message, GDB now prints
489 the message in the catchpoint hit notification. In GDB/MI mode, that
490 information is provided as an extra field named "exception-message"
491 in the *stopped notification.
493 * Trait objects can now be inspected When debugging Rust code. This
494 requires compiler support which will appear in Rust 1.24.
498 QEnvironmentHexEncoded
499 Inform GDBserver of an environment variable that is to be passed to
500 the inferior when starting it.
503 Inform GDBserver of an environment variable that is to be unset
504 before starting the remote inferior.
507 Inform GDBserver that the environment should be reset (i.e.,
508 user-set environment variables should be unset).
511 Indicates whether the inferior must be started with a shell or not.
514 Tell GDBserver that the inferior to be started should use a specific
517 * The "maintenance print c-tdesc" command now takes an optional
518 argument which is the file name of XML target description.
520 * The "maintenance selftest" command now takes an optional argument to
521 filter the tests to be run.
523 * The "enable", and "disable" commands now accept a range of
524 breakpoint locations, e.g. "enable 1.3-5".
529 Set and show the current working directory for the inferior.
532 Set and show compilation command used for compiling and injecting code
533 with the 'compile' commands.
535 set debug separate-debug-file
536 show debug separate-debug-file
537 Control the display of debug output about separate debug file search.
539 set dump-excluded-mappings
540 show dump-excluded-mappings
541 Control whether mappings marked with the VM_DONTDUMP flag should be
542 dumped when generating a core file.
545 List the registered selftests.
548 Start the debugged program stopping at the first instruction.
551 Control display of debugging messages related to OpenRISC targets.
553 set|show print type nested-type-limit
554 Set and show the limit of nesting level for nested types that the
555 type printer will show.
557 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
560 * Safer/improved support for debugging with no debug info
562 GDB no longer assumes functions with no debug information return
565 This means that GDB now refuses to call such functions unless you
566 tell it the function's type, by either casting the call to the
567 declared return type, or by casting the function to a function
568 pointer of the right type, and calling that:
570 (gdb) p getenv ("PATH")
571 'getenv' has unknown return type; cast the call to its declared return type
572 (gdb) p (char *) getenv ("PATH")
573 $1 = 0x7fffffffe "/usr/local/bin:/"...
574 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
575 $2 = 0x7fffffffe "/usr/local/bin:/"...
577 Similarly, GDB no longer assumes that global variables with no debug
578 info have type 'int', and refuses to print the variable's value
579 unless you tell it the variable's type:
582 'var' has unknown type; cast it to its declared type
586 * New native configurations
588 FreeBSD/aarch64 aarch64*-*-freebsd*
589 FreeBSD/arm arm*-*-freebsd*
593 FreeBSD/aarch64 aarch64*-*-freebsd*
594 FreeBSD/arm arm*-*-freebsd*
595 OpenRISC ELF or1k*-*-elf
597 * Removed targets and native configurations
599 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
601 *** Changes in GDB 8.0
603 * GDB now supports access to the PKU register on GNU/Linux. The register is
604 added by the Memory Protection Keys for Userspace feature which will be
605 available in future Intel CPUs.
607 * GDB now supports C++11 rvalue references.
611 ** New functions to start, stop and access a running btrace recording.
612 ** Rvalue references are now supported in gdb.Type.
614 * GDB now supports recording and replaying rdrand and rdseed Intel 64
617 * Building GDB and GDBserver now requires a C++11 compiler.
619 For example, GCC 4.8 or later.
621 It is no longer possible to build GDB or GDBserver with a C
622 compiler. The --disable-build-with-cxx configure option has been
625 * Building GDB and GDBserver now requires GNU make >= 3.81.
627 It is no longer supported to build GDB or GDBserver with another
628 implementation of the make program or an earlier version of GNU make.
630 * Native debugging on MS-Windows supports command-line redirection
632 Command-line arguments used for starting programs on MS-Windows can
633 now include redirection symbols supported by native Windows shells,
634 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
635 as "run", "start", and "set args", as well as the corresponding MI
638 * Support for thread names on MS-Windows.
640 GDB now catches and handles the special exception that programs
641 running on MS-Windows use to assign names to threads in the
644 * Support for Java programs compiled with gcj has been removed.
646 * User commands now accept an unlimited number of arguments.
647 Previously, only up to 10 was accepted.
649 * The "eval" command now expands user-defined command arguments.
651 This makes it easier to process a variable number of arguments:
656 eval "print $arg%d", $i
661 * Target descriptions can now describe registers for sparc32 and sparc64.
663 * GDB now supports DWARF version 5 (debug information format).
664 Its .debug_names index is not yet supported.
666 * New native configurations
668 FreeBSD/mips mips*-*-freebsd
672 Synopsys ARC arc*-*-elf32
673 FreeBSD/mips mips*-*-freebsd
675 * Removed targets and native configurations
677 Alpha running FreeBSD alpha*-*-freebsd*
678 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
683 Erases all the flash memory regions reported by the target.
685 maint print arc arc-instruction address
686 Print internal disassembler information about instruction at a given address.
690 set disassembler-options
691 show disassembler-options
692 Controls the passing of target specific information to the disassembler.
693 If it is necessary to specify more than one disassembler option then
694 multiple options can be placed together into a comma separated list.
695 The default value is the empty string. Currently, the only supported
696 targets are ARM, PowerPC and S/390.
701 Erases all the flash memory regions reported by the target. This is
702 equivalent to the CLI command flash-erase.
704 -file-list-shared-libraries
705 List the shared libraries in the program. This is
706 equivalent to the CLI command "info shared".
709 Catchpoints stopping the program when Ada exceptions are
710 handled. This is equivalent to the CLI command "catch handlers".
712 *** Changes in GDB 7.12
714 * GDB and GDBserver now build with a C++ compiler by default.
716 The --enable-build-with-cxx configure option is now enabled by
717 default. One must now explicitly configure with
718 --disable-build-with-cxx in order to build with a C compiler. This
719 option will be removed in a future release.
721 * GDBserver now supports recording btrace without maintaining an active
724 * GDB now supports a negative repeat count in the 'x' command to examine
725 memory backward from the given address. For example:
728 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
729 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
730 (gdb) x/-5i 0x0000000000400580
731 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
732 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
733 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
734 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
735 0x40057b <main(int, char**)+25>:
736 callq 0x400536 <Func1(int, char const*)>
738 * Fortran: Support structures with fields of dynamic types and
739 arrays of dynamic types.
741 * The symbol dumping maintenance commands have new syntax.
742 maint print symbols [-pc address] [--] [filename]
743 maint print symbols [-objfile objfile] [-source source] [--] [filename]
744 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
745 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
746 maint print msymbols [-objfile objfile] [--] [filename]
748 * GDB now supports multibit bitfields and enums in target register
751 * New Python-based convenience function $_as_string(val), which returns
752 the textual representation of a value. This function is especially
753 useful to obtain the text label of an enum value.
755 * Intel MPX bound violation handling.
757 Segmentation faults caused by a Intel MPX boundary violation
758 now display the kind of violation (upper or lower), the memory
759 address accessed and the memory bounds, along with the usual
760 signal received and code location.
764 Program received signal SIGSEGV, Segmentation fault
765 Upper bound violation while accessing address 0x7fffffffc3b3
766 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
767 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
769 * Rust language support.
770 GDB now supports debugging programs written in the Rust programming
771 language. See https://www.rust-lang.org/ for more information about
774 * Support for running interpreters on specified input/output devices
776 GDB now supports a new mechanism that allows frontends to provide
777 fully featured GDB console views, as a better alternative to
778 building such views on top of the "-interpreter-exec console"
779 command. See the new "new-ui" command below. With that command,
780 frontends can now start GDB in the traditional command-line mode
781 running in an embedded terminal emulator widget, and create a
782 separate MI interpreter running on a specified i/o device. In this
783 way, GDB handles line editing, history, tab completion, etc. in the
784 console all by itself, and the GUI uses the separate MI interpreter
785 for its own control and synchronization, invisible to the command
788 * The "catch syscall" command catches groups of related syscalls.
790 The "catch syscall" command now supports catching a group of related
791 syscalls using the 'group:' or 'g:' prefix.
796 skip -gfile file-glob-pattern
797 skip -function function
798 skip -rfunction regular-expression
799 A generalized form of the skip command, with new support for
800 glob-style file names and regular expressions for function names.
801 Additionally, a file spec and a function spec may now be combined.
803 maint info line-table REGEXP
804 Display the contents of GDB's internal line table data struture.
807 Run any GDB unit tests that were compiled in.
810 Start a new user interface instance running INTERP as interpreter,
811 using the TTY file for input/output.
815 ** gdb.Breakpoint objects have a new attribute "pending", which
816 indicates whether the breakpoint is pending.
817 ** Three new breakpoint-related events have been added:
818 gdb.breakpoint_created, gdb.breakpoint_modified, and
819 gdb.breakpoint_deleted.
822 Signal ("set") the given MS-Windows event object. This is used in
823 conjunction with the Windows JIT debugging (AeDebug) support, where
824 the OS suspends a crashing process until a debugger can attach to
825 it. Resuming the crashing process, in order to debug it, is done by
828 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
829 was added in GDBserver, including JIT compiling fast tracepoint's
830 conditional expression bytecode into native code.
832 * Support for various remote target protocols and ROM monitors has
835 target m32rsdi Remote M32R debugging over SDI
836 target mips MIPS remote debugging protocol
837 target pmon PMON ROM monitor
838 target ddb NEC's DDB variant of PMON for Vr4300
839 target rockhopper NEC RockHopper variant of PMON
840 target lsi LSI variant of PMO
842 * Support for tracepoints and fast tracepoints on powerpc-linux,
843 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
844 including JIT compiling fast tracepoint's conditional expression
845 bytecode into native code.
847 * MI async record =record-started now includes the method and format used for
848 recording. For example:
850 =record-started,thread-group="i1",method="btrace",format="bts"
852 * MI async record =thread-selected now includes the frame field. For example:
854 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
858 Andes NDS32 nds32*-*-elf
860 *** Changes in GDB 7.11
862 * GDB now supports debugging kernel-based threads on FreeBSD.
864 * Per-inferior thread numbers
866 Thread numbers are now per inferior instead of global. If you're
867 debugging multiple inferiors, GDB displays thread IDs using a
868 qualified INF_NUM.THR_NUM form. For example:
872 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
873 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
874 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
875 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
877 As consequence, thread numbers as visible in the $_thread
878 convenience variable and in Python's InferiorThread.num attribute
879 are no longer unique between inferiors.
881 GDB now maintains a second thread ID per thread, referred to as the
882 global thread ID, which is the new equivalent of thread numbers in
883 previous releases. See also $_gthread below.
885 For backwards compatibility, MI's thread IDs always refer to global
888 * Commands that accept thread IDs now accept the qualified
889 INF_NUM.THR_NUM form as well. For example:
892 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
895 * In commands that accept a list of thread IDs, you can now refer to
896 all threads of an inferior using a star wildcard. GDB accepts
897 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
898 refer to all threads of the current inferior. For example, "info
901 * You can use "info threads -gid" to display the global thread ID of
904 * The new convenience variable $_gthread holds the global number of
907 * The new convenience variable $_inferior holds the number of the
910 * GDB now displays the ID and name of the thread that hit a breakpoint
911 or received a signal, if your program is multi-threaded. For
914 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
915 Thread 1 "main" received signal SIGINT, Interrupt.
917 * Record btrace now supports non-stop mode.
919 * Support for tracepoints on aarch64-linux was added in GDBserver.
921 * The 'record instruction-history' command now indicates speculative execution
922 when using the Intel Processor Trace recording format.
924 * GDB now allows users to specify explicit locations, bypassing
925 the linespec parser. This feature is also available to GDB/MI
928 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
929 GDB now is able to debug both AArch64 applications and ARM applications
932 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
933 including JIT compiling fast tracepoint's conditional expression bytecode
936 * GDB now supports displaced stepping on AArch64 GNU/Linux.
938 * "info threads", "info inferiors", "info display", "info checkpoints"
939 and "maint info program-spaces" now list the corresponding items in
940 ascending ID order, for consistency with all other "info" commands.
942 * In Ada, the overloads selection menu has been enhanced to display the
943 parameter types and the return types for the matching overloaded subprograms.
947 maint set target-non-stop (on|off|auto)
948 maint show target-non-stop
949 Control whether GDB targets always operate in non-stop mode even if
950 "set non-stop" is "off". The default is "auto", meaning non-stop
951 mode is enabled if supported by the target.
953 maint set bfd-sharing
954 maint show bfd-sharing
955 Control the reuse of bfd objects.
959 Control display of debugging info regarding bfd caching.
963 Control display of debugging info regarding FreeBSD threads.
965 set remote multiprocess-extensions-packet
966 show remote multiprocess-extensions-packet
967 Set/show the use of the remote protocol multiprocess extensions.
969 set remote thread-events
970 show remote thread-events
971 Set/show the use of thread create/exit events.
973 set ada print-signatures on|off
974 show ada print-signatures"
975 Control whether parameter types and return types are displayed in overloads
976 selection menus. It is activaled (@code{on}) by default.
980 Controls the maximum size of memory, in bytes, that GDB will
981 allocate for value contents. Prevents incorrect programs from
982 causing GDB to allocate overly large buffers. Default is 64k.
984 * The "disassemble" command accepts a new modifier: /s.
985 It prints mixed source+disassembly like /m with two differences:
986 - disassembled instructions are now printed in program order, and
987 - and source for all relevant files is now printed.
988 The "/m" option is now considered deprecated: its "source-centric"
989 output hasn't proved useful in practice.
991 * The "record instruction-history" command accepts a new modifier: /s.
992 It behaves exactly like /m and prints mixed source+disassembly.
994 * The "set scheduler-locking" command supports a new mode "replay".
995 It behaves like "off" in record mode and like "on" in replay mode.
997 * Support for various ROM monitors has been removed:
999 target dbug dBUG ROM monitor for Motorola ColdFire
1000 target picobug Motorola picobug monitor
1001 target dink32 DINK32 ROM monitor for PowerPC
1002 target m32r Renesas M32R/D ROM monitor
1003 target mon2000 mon2000 ROM monitor
1004 target ppcbug PPCBUG ROM monitor for PowerPC
1006 * Support for reading/writing memory and extracting values on architectures
1007 whose memory is addressable in units of any integral multiple of 8 bits.
1010 Allows to break when an Ada exception is handled.
1012 * New remote packets
1015 Indicates that an exec system call was executed.
1017 exec-events feature in qSupported
1018 The qSupported packet allows GDB to request support for exec
1019 events using the new 'gdbfeature' exec-event, and the qSupported
1020 response can contain the corresponding 'stubfeature'. Set and
1021 show commands can be used to display whether these features are enabled.
1024 Equivalent to interrupting with the ^C character, but works in
1027 thread created stop reason (T05 create:...)
1028 Indicates that the thread was just created and is stopped at entry.
1030 thread exit stop reply (w exitcode;tid)
1031 Indicates that the thread has terminated.
1034 Enables/disables thread create and exit event reporting. For
1035 example, this is used in non-stop mode when GDB stops a set of
1036 threads and synchronously waits for the their corresponding stop
1037 replies. Without exit events, if one of the threads exits, GDB
1038 would hang forever not knowing that it should no longer expect a
1039 stop for that same thread.
1042 Indicates that there are no resumed threads left in the target (all
1043 threads are stopped). The remote stub reports support for this stop
1044 reply to GDB's qSupported query.
1047 Enables/disables catching syscalls from the inferior process.
1048 The remote stub reports support for this packet to GDB's qSupported query.
1050 syscall_entry stop reason
1051 Indicates that a syscall was just called.
1053 syscall_return stop reason
1054 Indicates that a syscall just returned.
1056 * Extended-remote exec events
1058 ** GDB now has support for exec events on extended-remote Linux targets.
1059 For such targets with Linux kernels 2.5.46 and later, this enables
1060 follow-exec-mode and exec catchpoints.
1062 set remote exec-event-feature-packet
1063 show remote exec-event-feature-packet
1064 Set/show the use of the remote exec event feature.
1066 * Thread names in remote protocol
1068 The reply to qXfer:threads:read may now include a name attribute for each
1071 * Target remote mode fork and exec events
1073 ** GDB now has support for fork and exec events on target remote mode
1074 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1075 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1076 fork and exec catchpoints.
1078 * Remote syscall events
1080 ** GDB now has support for catch syscall on remote Linux targets,
1081 currently enabled on x86/x86_64 architectures.
1083 set remote catch-syscall-packet
1084 show remote catch-syscall-packet
1085 Set/show the use of the remote catch syscall feature.
1089 ** The -var-set-format command now accepts the zero-hexadecimal
1090 format. It outputs data in hexadecimal format with zero-padding on the
1095 ** gdb.InferiorThread objects have a new attribute "global_num",
1096 which refers to the thread's global thread ID. The existing
1097 "num" attribute now refers to the thread's per-inferior number.
1098 See "Per-inferior thread numbers" above.
1099 ** gdb.InferiorThread objects have a new attribute "inferior", which
1100 is the Inferior object the thread belongs to.
1102 *** Changes in GDB 7.10
1104 * Support for process record-replay and reverse debugging on aarch64*-linux*
1105 targets has been added. GDB now supports recording of A64 instruction set
1106 including advance SIMD instructions.
1108 * Support for Sun's version of the "stabs" debug file format has been removed.
1110 * GDB now honors the content of the file /proc/PID/coredump_filter
1111 (PID is the process ID) on GNU/Linux systems. This file can be used
1112 to specify the types of memory mappings that will be included in a
1113 corefile. For more information, please refer to the manual page of
1114 "core(5)". GDB also has a new command: "set use-coredump-filter
1115 on|off". It allows to set whether GDB will read the content of the
1116 /proc/PID/coredump_filter file when generating a corefile.
1118 * The "info os" command on GNU/Linux can now display information on
1120 "info os cpus" Listing of all cpus/cores on the system
1122 * GDB has two new commands: "set serial parity odd|even|none" and
1123 "show serial parity". These allows to set or show parity for the
1126 * The "info source" command now displays the producer string if it was
1127 present in the debug info. This typically includes the compiler version
1128 and may include things like its command line arguments.
1130 * The "info dll", an alias of the "info sharedlibrary" command,
1131 is now available on all platforms.
1133 * Directory names supplied to the "set sysroot" commands may be
1134 prefixed with "target:" to tell GDB to access shared libraries from
1135 the target system, be it local or remote. This replaces the prefix
1136 "remote:". The default sysroot has been changed from "" to
1137 "target:". "remote:" is automatically converted to "target:" for
1138 backward compatibility.
1140 * The system root specified by "set sysroot" will be prepended to the
1141 filename of the main executable (if reported to GDB as absolute by
1142 the operating system) when starting processes remotely, and when
1143 attaching to already-running local or remote processes.
1145 * GDB now supports automatic location and retrieval of executable
1146 files from remote targets. Remote debugging can now be initiated
1147 using only a "target remote" or "target extended-remote" command
1148 (no "set sysroot" or "file" commands are required). See "New remote
1151 * The "dump" command now supports verilog hex format.
1153 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1155 * On GNU/Linux, GDB and gdbserver are now able to access executable
1156 and shared library files without a "set sysroot" command when
1157 attaching to processes running in different mount namespaces from
1158 the debugger. This makes it possible to attach to processes in
1159 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1160 See "New remote packets" below.
1162 * The "tui reg" command now provides completion for all of the
1163 available register groups, including target specific groups.
1165 * The HISTSIZE environment variable is no longer read when determining
1166 the size of GDB's command history. GDB now instead reads the dedicated
1167 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1168 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1173 ** Memory ports can now be unbuffered.
1177 ** gdb.Objfile objects have a new attribute "username",
1178 which is the name of the objfile as specified by the user,
1179 without, for example, resolving symlinks.
1180 ** You can now write frame unwinders in Python.
1181 ** gdb.Type objects have a new method "optimized_out",
1182 returning optimized out gdb.Value instance of this type.
1183 ** gdb.Value objects have new methods "reference_value" and
1184 "const_value" which return a reference to the value and a
1185 "const" version of the value respectively.
1189 maint print symbol-cache
1190 Print the contents of the symbol cache.
1192 maint print symbol-cache-statistics
1193 Print statistics of symbol cache usage.
1195 maint flush-symbol-cache
1196 Flush the contents of the symbol cache.
1200 Start branch trace recording using Branch Trace Store (BTS) format.
1203 Evaluate expression by using the compiler and print result.
1207 Explicit commands for enabling and disabling tui mode.
1210 set mpx bound on i386 and amd64
1211 Support for bound table investigation on Intel MPX enabled applications.
1215 Start branch trace recording using Intel Processor Trace format.
1218 Print information about branch tracing internals.
1220 maint btrace packet-history
1221 Print the raw branch tracing data.
1223 maint btrace clear-packet-history
1224 Discard the stored raw branch tracing data.
1227 Discard all branch tracing data. It will be fetched and processed
1228 anew by the next "record" command.
1233 Renamed from "set debug dwarf2-die".
1234 show debug dwarf-die
1235 Renamed from "show debug dwarf2-die".
1237 set debug dwarf-read
1238 Renamed from "set debug dwarf2-read".
1239 show debug dwarf-read
1240 Renamed from "show debug dwarf2-read".
1242 maint set dwarf always-disassemble
1243 Renamed from "maint set dwarf2 always-disassemble".
1244 maint show dwarf always-disassemble
1245 Renamed from "maint show dwarf2 always-disassemble".
1247 maint set dwarf max-cache-age
1248 Renamed from "maint set dwarf2 max-cache-age".
1249 maint show dwarf max-cache-age
1250 Renamed from "maint show dwarf2 max-cache-age".
1252 set debug dwarf-line
1253 show debug dwarf-line
1254 Control display of debugging info regarding DWARF line processing.
1257 show max-completions
1258 Set the maximum number of candidates to be considered during
1259 completion. The default value is 200. This limit allows GDB
1260 to avoid generating large completion lists, the computation of
1261 which can cause the debugger to become temporarily unresponsive.
1263 set history remove-duplicates
1264 show history remove-duplicates
1265 Control the removal of duplicate history entries.
1267 maint set symbol-cache-size
1268 maint show symbol-cache-size
1269 Control the size of the symbol cache.
1271 set|show record btrace bts buffer-size
1272 Set and show the size of the ring buffer used for branch tracing in
1274 The obtained size may differ from the requested size. Use "info
1275 record" to see the obtained buffer size.
1277 set debug linux-namespaces
1278 show debug linux-namespaces
1279 Control display of debugging info regarding Linux namespaces.
1281 set|show record btrace pt buffer-size
1282 Set and show the size of the ring buffer used for branch tracing in
1283 Intel Processor Trace format.
1284 The obtained size may differ from the requested size. Use "info
1285 record" to see the obtained buffer size.
1287 maint set|show btrace pt skip-pad
1288 Set and show whether PAD packets are skipped when computing the
1291 * The command 'thread apply all' can now support new option '-ascending'
1292 to call its specified command for all threads in ascending order.
1294 * Python/Guile scripting
1296 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1297 special section named `.debug_gdb_scripts'.
1299 * New remote packets
1301 qXfer:btrace-conf:read
1302 Return the branch trace configuration for the current thread.
1304 Qbtrace-conf:bts:size
1305 Set the requested ring buffer size for branch tracing in BTS format.
1308 Enable Intel Procesor Trace-based branch tracing for the current
1309 process. The remote stub reports support for this packet to GDB's
1312 Qbtrace-conf:pt:size
1313 Set the requested ring buffer size for branch tracing in Intel Processor
1317 Indicates a memory breakpoint instruction was executed, irrespective
1318 of whether it was GDB that planted the breakpoint or the breakpoint
1319 is hardcoded in the program. This is required for correct non-stop
1323 Indicates the target stopped for a hardware breakpoint. This is
1324 required for correct non-stop mode operation.
1327 Return information about files on the remote system.
1329 qXfer:exec-file:read
1330 Return the full absolute name of the file that was executed to
1331 create a process running on the remote system.
1334 Select the filesystem on which vFile: operations with filename
1335 arguments will operate. This is required for GDB to be able to
1336 access files on remote targets where the remote stub does not
1337 share a common filesystem with the inferior(s).
1340 Indicates that a fork system call was executed.
1343 Indicates that a vfork system call was executed.
1345 vforkdone stop reason
1346 Indicates that a vfork child of the specified process has executed
1347 an exec or exit, allowing the vfork parent to resume execution.
1349 fork-events and vfork-events features in qSupported
1350 The qSupported packet allows GDB to request support for fork and
1351 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1352 and the qSupported response can contain the corresponding
1353 'stubfeatures'. Set and show commands can be used to display
1354 whether these features are enabled.
1356 * Extended-remote fork events
1358 ** GDB now has support for fork events on extended-remote Linux
1359 targets. For targets with Linux kernels 2.5.60 and later, this
1360 enables follow-fork-mode and detach-on-fork for both fork and
1361 vfork, as well as fork and vfork catchpoints.
1363 * The info record command now shows the recording format and the
1364 branch tracing configuration for the current thread when using
1365 the btrace record target.
1366 For the BTS format, it shows the ring buffer size.
1368 * GDB now has support for DTrace USDT (Userland Static Defined
1369 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1371 * GDB now supports access to vector registers on S/390 GNU/Linux
1374 * Removed command line options
1376 -xdb HP-UX XDB compatibility mode.
1378 * Removed targets and native configurations
1380 HP/PA running HP-UX hppa*-*-hpux*
1381 Itanium running HP-UX ia64-*-hpux*
1383 * New configure options
1386 This configure option allows the user to build GDB with support for
1387 Intel Processor Trace (default: auto). This requires libipt.
1389 --with-libipt-prefix=PATH
1390 Specify the path to the version of libipt that GDB should use.
1391 $PATH/include should contain the intel-pt.h header and
1392 $PATH/lib should contain the libipt.so library.
1394 *** Changes in GDB 7.9.1
1398 ** Xmethods can now specify a result type.
1400 *** Changes in GDB 7.9
1402 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1406 ** You can now access frame registers from Python scripts.
1407 ** New attribute 'producer' for gdb.Symtab objects.
1408 ** gdb.Objfile objects have a new attribute "progspace",
1409 which is the gdb.Progspace object of the containing program space.
1410 ** gdb.Objfile objects have a new attribute "owner".
1411 ** gdb.Objfile objects have a new attribute "build_id",
1412 which is the build ID generated when the file was built.
1413 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1414 ** A new event "gdb.clear_objfiles" has been added, triggered when
1415 selecting a new file to debug.
1416 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1417 ** New function gdb.lookup_objfile.
1419 New events which are triggered when GDB modifies the state of the
1422 ** gdb.events.inferior_call_pre: Function call is about to be made.
1423 ** gdb.events.inferior_call_post: Function call has just been made.
1424 ** gdb.events.memory_changed: A memory location has been altered.
1425 ** gdb.events.register_changed: A register has been altered.
1427 * New Python-based convenience functions:
1429 ** $_caller_is(name [, number_of_frames])
1430 ** $_caller_matches(regexp [, number_of_frames])
1431 ** $_any_caller_is(name [, number_of_frames])
1432 ** $_any_caller_matches(regexp [, number_of_frames])
1434 * GDB now supports the compilation and injection of source code into
1435 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1436 to compile the source code to object code, and if successful, inject
1437 and execute that code within the current context of the inferior.
1438 Currently the C language is supported. The commands used to
1439 interface with this new feature are:
1441 compile code [-raw|-r] [--] [source code]
1442 compile file [-raw|-r] filename
1446 demangle [-l language] [--] name
1447 Demangle "name" in the specified language, or the current language
1448 if elided. This command is renamed from the "maint demangle" command.
1449 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1450 as "maint demangler-warning".
1452 queue-signal signal-name-or-number
1453 Queue a signal to be delivered to the thread when it is resumed.
1455 add-auto-load-scripts-directory directory
1456 Add entries to the list of directories from which to load auto-loaded
1459 maint print user-registers
1460 List all currently available "user" registers.
1462 compile code [-r|-raw] [--] [source code]
1463 Compile, inject, and execute in the inferior the executable object
1464 code produced by compiling the provided source code.
1466 compile file [-r|-raw] filename
1467 Compile and inject into the inferior the executable object code
1468 produced by compiling the source code stored in the filename
1471 * On resume, GDB now always passes the signal the program had stopped
1472 for to the thread the signal was sent to, even if the user changed
1473 threads before resuming. Previously GDB would often (but not
1474 always) deliver the signal to the thread that happens to be current
1477 * Conversely, the "signal" command now consistently delivers the
1478 requested signal to the current thread. GDB now asks for
1479 confirmation if the program had stopped for a signal and the user
1480 switched threads meanwhile.
1482 * "breakpoint always-inserted" modes "off" and "auto" merged.
1484 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1485 won't remove breakpoints from the target until all threads stop,
1486 even in non-stop mode. The "auto" mode has been removed, and "off"
1487 is now the default mode.
1491 set debug symbol-lookup
1492 show debug symbol-lookup
1493 Control display of debugging info regarding symbol lookup.
1497 ** The -list-thread-groups command outputs an exit-code field for
1498 inferiors that have exited.
1502 MIPS SDE mips*-sde*-elf*
1506 Support for these obsolete configurations has been removed.
1508 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1509 SGI Irix-5.x mips-*-irix5*
1510 SGI Irix-6.x mips-*-irix6*
1511 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1512 VAX running Ultrix vax-*-ultrix*
1514 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1515 and "assf"), have been removed. Use the "sharedlibrary" command, or
1516 its alias "share", instead.
1518 *** Changes in GDB 7.8
1520 * New command line options
1523 This is an alias for the --data-directory option.
1525 * GDB supports printing and modifying of variable length automatic arrays
1526 as specified in ISO C99.
1528 * The ARM simulator now supports instruction level tracing
1529 with or without disassembly.
1533 GDB now has support for scripting using Guile. Whether this is
1534 available is determined at configure time.
1535 Guile version 2.0 or greater is required.
1536 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1538 * New commands (for set/show, see "New options" below)
1542 Invoke CODE by passing it to the Guile interpreter.
1546 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1548 info auto-load guile-scripts [regexp]
1549 Print the list of automatically loaded Guile scripts.
1551 * The source command is now capable of sourcing Guile scripts.
1552 This feature is dependent on the debugger being built with Guile support.
1556 set print symbol-loading (off|brief|full)
1557 show print symbol-loading
1558 Control whether to print informational messages when loading symbol
1559 information for a file. The default is "full", but when debugging
1560 programs with large numbers of shared libraries the amount of output
1561 becomes less useful.
1563 set guile print-stack (none|message|full)
1564 show guile print-stack
1565 Show a stack trace when an error is encountered in a Guile script.
1567 set auto-load guile-scripts (on|off)
1568 show auto-load guile-scripts
1569 Control auto-loading of Guile script files.
1571 maint ada set ignore-descriptive-types (on|off)
1572 maint ada show ignore-descriptive-types
1573 Control whether the debugger should ignore descriptive types in Ada
1574 programs. The default is not to ignore the descriptive types. See
1575 the user manual for more details on descriptive types and the intended
1576 usage of this option.
1578 set auto-connect-native-target
1580 Control whether GDB is allowed to automatically connect to the
1581 native target for the run, attach, etc. commands when not connected
1582 to any target yet. See also "target native" below.
1584 set record btrace replay-memory-access (read-only|read-write)
1585 show record btrace replay-memory-access
1586 Control what memory accesses are allowed during replay.
1588 maint set target-async (on|off)
1589 maint show target-async
1590 This controls whether GDB targets operate in synchronous or
1591 asynchronous mode. Normally the default is asynchronous, if it is
1592 available; but this can be changed to more easily debug problems
1593 occurring only in synchronous mode.
1595 set mi-async (on|off)
1597 Control whether MI asynchronous mode is preferred. This supersedes
1598 "set target-async" of previous GDB versions.
1600 * "set target-async" is deprecated as a CLI option and is now an alias
1601 for "set mi-async" (only puts MI into async mode).
1603 * Background execution commands (e.g., "c&", "s&", etc.) are now
1604 possible ``out of the box'' if the target supports them. Previously
1605 the user would need to explicitly enable the possibility with the
1606 "set target-async on" command.
1608 * New features in the GDB remote stub, GDBserver
1610 ** New option --debug-format=option1[,option2,...] allows one to add
1611 additional text to each output. At present only timestamps
1612 are supported: --debug-format=timestamps.
1613 Timestamps can also be turned on with the
1614 "monitor set debug-format timestamps" command from GDB.
1616 * The 'record instruction-history' command now starts counting instructions
1617 at one. This also affects the instruction ranges reported by the
1618 'record function-call-history' command when given the /i modifier.
1620 * The command 'record function-call-history' supports a new modifier '/c' to
1621 indent the function names based on their call stack depth.
1622 The fields for the '/i' and '/l' modifier have been reordered.
1623 The source line range is now prefixed with 'at'.
1624 The instruction range is now prefixed with 'inst'.
1625 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1626 "record instruction-history" and "list" commands.
1628 * The ranges given as arguments to the 'record function-call-history' and
1629 'record instruction-history' commands are now inclusive.
1631 * The btrace record target now supports the 'record goto' command.
1632 For locations inside the execution trace, the back trace is computed
1633 based on the information stored in the execution trace.
1635 * The btrace record target supports limited reverse execution and replay.
1636 The target does not record data and therefore does not allow reading
1637 memory or registers.
1639 * The "catch syscall" command now works on s390*-linux* targets.
1641 * The "compare-sections" command is no longer specific to target
1642 remote. It now works with all targets.
1644 * All native targets are now consistently called "native".
1645 Consequently, the "target child", "target GNU", "target djgpp",
1646 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1647 commands have been replaced with "target native". The QNX/NTO port
1648 leaves the "procfs" target in place and adds a "native" target for
1649 consistency with other ports. The impact on users should be minimal
1650 as these commands previously either throwed an error, or were
1651 no-ops. The target's name is visible in the output of the following
1652 commands: "help target", "info target", "info files", "maint print
1655 * The "target native" command now connects to the native target. This
1656 can be used to launch native programs even when "set
1657 auto-connect-native-target" is set to off.
1659 * GDB now supports access to Intel MPX registers on GNU/Linux.
1661 * Support for Intel AVX-512 registers on GNU/Linux.
1662 Support displaying and modifying Intel AVX-512 registers
1663 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1665 * New remote packets
1667 qXfer:btrace:read's annex
1668 The qXfer:btrace:read packet supports a new annex 'delta' to read
1669 branch trace incrementally.
1673 ** Valid Python operations on gdb.Value objects representing
1674 structs/classes invoke the corresponding overloaded operators if
1676 ** New `Xmethods' feature in the Python API. Xmethods are
1677 additional methods or replacements for existing methods of a C++
1678 class. This feature is useful for those cases where a method
1679 defined in C++ source code could be inlined or optimized out by
1680 the compiler, making it unavailable to GDB.
1683 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1685 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1686 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1687 its alias "share", instead.
1689 * The commands "set remotebaud" and "show remotebaud" are no longer
1690 supported. Use "set serial baud" and "show serial baud" (respectively)
1695 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1696 target-async". The latter is left as a deprecated alias of the
1697 former for backward compatibility. If the target supports it,
1698 CLI background execution commands are now always possible by
1699 default, independently of whether the frontend stated a
1700 preference for asynchronous execution with "-gdb-set mi-async".
1701 Previously "-gdb-set target-async off" affected both MI execution
1702 commands and CLI execution commands.
1704 *** Changes in GDB 7.7
1706 * Improved support for process record-replay and reverse debugging on
1707 arm*-linux* targets. Support for thumb32 and syscall instruction
1708 recording has been added.
1710 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1712 * GDB now supports Fission DWP file format version 2.
1713 http://gcc.gnu.org/wiki/DebugFission
1715 * New convenience function "$_isvoid", to check whether an expression
1716 is void. A void expression is an expression where the type of the
1717 result is "void". For example, some convenience variables may be
1718 "void" when evaluated (e.g., "$_exitcode" before the execution of
1719 the program being debugged; or an undefined convenience variable).
1720 Another example, when calling a function whose return type is
1723 * The "maintenance print objfiles" command now takes an optional regexp.
1725 * The "catch syscall" command now works on arm*-linux* targets.
1727 * GDB now consistently shows "<not saved>" when printing values of
1728 registers the debug info indicates have not been saved in the frame
1729 and there's nowhere to retrieve them from
1730 (callee-saved/call-clobbered registers):
1735 (gdb) info registers rax
1738 Before, the former would print "<optimized out>", and the latter
1739 "*value not available*".
1741 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1746 ** Frame filters and frame decorators have been added.
1747 ** Temporary breakpoints are now supported.
1748 ** Line tables representation has been added.
1749 ** New attribute 'parent_type' for gdb.Field objects.
1750 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1751 ** New attribute 'name' for gdb.Type objects.
1755 Nios II ELF nios2*-*-elf
1756 Nios II GNU/Linux nios2*-*-linux
1757 Texas Instruments MSP430 msp430*-*-elf
1759 * Removed native configurations
1761 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1762 been removed. ELF variants of these configurations are kept supported.
1764 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1765 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1766 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1767 i[34567]86-*-openbsd3.[0-3]
1768 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1769 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1770 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1774 Like "catch throw", but catches a re-thrown exception.
1775 maint check-psymtabs
1776 Renamed from old "maint check-symtabs".
1778 Perform consistency checks on symtabs.
1779 maint expand-symtabs
1780 Expand symtabs matching an optional regexp.
1783 Display the details of GDB configure-time options.
1785 maint set|show per-command
1786 maint set|show per-command space
1787 maint set|show per-command time
1788 maint set|show per-command symtab
1789 Enable display of per-command gdb resource usage.
1791 remove-symbol-file FILENAME
1792 remove-symbol-file -a ADDRESS
1793 Remove a symbol file added via add-symbol-file. The file to remove
1794 can be identified by its filename or by an address that lies within
1795 the boundaries of this symbol file in memory.
1798 info exceptions REGEXP
1799 Display the list of Ada exceptions defined in the program being
1800 debugged. If provided, only the exceptions whose names match REGEXP
1805 set debug symfile off|on
1807 Control display of debugging info regarding reading symbol files and
1808 symbol tables within those files
1810 set print raw frame-arguments
1811 show print raw frame-arguments
1812 Set/show whether to print frame arguments in raw mode,
1813 disregarding any defined pretty-printers.
1815 set remote trace-status-packet
1816 show remote trace-status-packet
1817 Set/show the use of remote protocol qTStatus packet.
1821 Control display of debugging messages related to Nios II targets.
1825 Control whether target-assisted range stepping is enabled.
1827 set startup-with-shell
1828 show startup-with-shell
1829 Specifies whether Unix child processes are started via a shell or
1834 Use the target memory cache for accesses to the code segment. This
1835 improves performance of remote debugging (particularly disassembly).
1837 * You can now use a literal value 'unlimited' for options that
1838 interpret 0 or -1 as meaning "unlimited". E.g., "set
1839 trace-buffer-size unlimited" is now an alias for "set
1840 trace-buffer-size -1" and "set height unlimited" is now an alias for
1843 * The "set debug symtab-create" debugging option of GDB has been changed to
1844 accept a verbosity level. 0 means "off", 1 provides basic debugging
1845 output, and values of 2 or greater provides more verbose output.
1847 * New command-line options
1849 Display the details of GDB configure-time options.
1851 * The command 'tsave' can now support new option '-ctf' to save trace
1852 buffer in Common Trace Format.
1854 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1857 * GDB now implements the the C++ 'typeid' operator.
1859 * The new convenience variable $_exception holds the exception being
1860 thrown or caught at an exception-related catchpoint.
1862 * The exception-related catchpoints, like "catch throw", now accept a
1863 regular expression which can be used to filter exceptions by type.
1865 * The new convenience variable $_exitsignal is automatically set to
1866 the terminating signal number when the program being debugged dies
1867 due to an uncaught signal.
1871 ** All MI commands now accept an optional "--language" option.
1872 Support for this feature can be verified by using the "-list-features"
1873 command, which should contain "language-option".
1875 ** The new command -info-gdb-mi-command allows the user to determine
1876 whether a GDB/MI command is supported or not.
1878 ** The "^error" result record returned when trying to execute an undefined
1879 GDB/MI command now provides a variable named "code" whose content is the
1880 "undefined-command" error code. Support for this feature can be verified
1881 by using the "-list-features" command, which should contain
1882 "undefined-command-error-code".
1884 ** The -trace-save MI command can optionally save trace buffer in Common
1887 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1889 ** The command -data-list-register-values now accepts an optional
1890 "--skip-unavailable" option. When used, only the available registers
1893 ** The new command -trace-frame-collected dumps collected variables,
1894 computed expressions, tvars, memory and registers in a traceframe.
1896 ** The commands -stack-list-locals, -stack-list-arguments and
1897 -stack-list-variables now accept an option "--skip-unavailable".
1898 When used, only the available locals or arguments are displayed.
1900 ** The -exec-run command now accepts an optional "--start" option.
1901 When used, the command follows the same semantics as the "start"
1902 command, stopping the program's execution at the start of its
1903 main subprogram. Support for this feature can be verified using
1904 the "-list-features" command, which should contain
1905 "exec-run-start-option".
1907 ** The new commands -catch-assert and -catch-exceptions insert
1908 catchpoints stopping the program when Ada exceptions are raised.
1910 ** The new command -info-ada-exceptions provides the equivalent of
1911 the new "info exceptions" command.
1913 * New system-wide configuration scripts
1914 A GDB installation now provides scripts suitable for use as system-wide
1915 configuration scripts for the following systems:
1919 * GDB now supports target-assigned range stepping with remote targets.
1920 This improves the performance of stepping source lines by reducing
1921 the number of control packets from/to GDB. See "New remote packets"
1924 * GDB now understands the element 'tvar' in the XML traceframe info.
1925 It has the id of the collected trace state variables.
1927 * On S/390 targets that provide the transactional-execution feature,
1928 the program interruption transaction diagnostic block (TDB) is now
1929 represented as a number of additional "registers" in GDB.
1931 * New remote packets
1935 The vCont packet supports a new 'r' action, that tells the remote
1936 stub to step through an address range itself, without GDB
1937 involvemement at each single-step.
1939 qXfer:libraries-svr4:read's annex
1940 The previously unused annex of the qXfer:libraries-svr4:read packet
1941 is now used to support passing an argument list. The remote stub
1942 reports support for this argument list to GDB's qSupported query.
1943 The defined arguments are "start" and "prev", used to reduce work
1944 necessary for library list updating, resulting in significant
1947 * New features in the GDB remote stub, GDBserver
1949 ** GDBserver now supports target-assisted range stepping. Currently
1950 enabled on x86/x86_64 GNU/Linux targets.
1952 ** GDBserver now adds element 'tvar' in the XML in the reply to
1953 'qXfer:traceframe-info:read'. It has the id of the collected
1954 trace state variables.
1956 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1959 * New 'z' formatter for printing and examining memory, this displays the
1960 value as hexadecimal zero padded on the left to the size of the type.
1962 * GDB can now use Windows x64 unwinding data.
1964 * The "set remotebaud" command has been replaced by "set serial baud".
1965 Similarly, "show remotebaud" has been replaced by "show serial baud".
1966 The "set remotebaud" and "show remotebaud" commands are still available
1967 to provide backward compatibility with older versions of GDB.
1969 *** Changes in GDB 7.6
1971 * Target record has been renamed to record-full.
1972 Record/replay is now enabled with the "record full" command.
1973 This also affects settings that are associated with full record/replay
1974 that have been moved from "set/show record" to "set/show record full":
1976 set|show record full insn-number-max
1977 set|show record full stop-at-limit
1978 set|show record full memory-query
1980 * A new record target "record-btrace" has been added. The new target
1981 uses hardware support to record the control-flow of a process. It
1982 does not support replaying the execution, but it implements the
1983 below new commands for investigating the recorded execution log.
1984 This new recording method can be enabled using:
1988 The "record-btrace" target is only available on Intel Atom processors
1989 and requires a Linux kernel 2.6.32 or later.
1991 * Two new commands have been added for record/replay to give information
1992 about the recorded execution without having to replay the execution.
1993 The commands are only supported by "record btrace".
1995 record instruction-history prints the execution history at
1996 instruction granularity
1998 record function-call-history prints the execution history at
1999 function granularity
2001 * New native configurations
2003 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2004 FreeBSD/powerpc powerpc*-*-freebsd
2005 x86_64/Cygwin x86_64-*-cygwin*
2006 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2010 ARM AArch64 aarch64*-*-elf
2011 ARM AArch64 GNU/Linux aarch64*-*-linux
2012 Lynx 178 PowerPC powerpc-*-lynx*178
2013 x86_64/Cygwin x86_64-*-cygwin*
2014 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2016 * If the configured location of system.gdbinit file (as given by the
2017 --with-system-gdbinit option at configure time) is in the
2018 data-directory (as specified by --with-gdb-datadir at configure
2019 time) or in one of its subdirectories, then GDB will look for the
2020 system-wide init file in the directory specified by the
2021 --data-directory command-line option.
2023 * New command line options:
2025 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2026 other initialization files, unlike -nx which disables all of them.
2028 * Removed command line options
2030 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2033 * The 'ptype' and 'whatis' commands now accept an argument to control
2036 * 'info proc' now works on some core files.
2040 ** Vectors can be created with gdb.Type.vector.
2042 ** Python's atexit.register now works in GDB.
2044 ** Types can be pretty-printed via a Python API.
2046 ** Python 3 is now supported (in addition to Python 2.4 or later)
2048 ** New class gdb.Architecture exposes GDB's internal representation
2049 of architecture in the Python API.
2051 ** New method Frame.architecture returns the gdb.Architecture object
2052 corresponding to the frame's architecture.
2054 * New Python-based convenience functions:
2056 ** $_memeq(buf1, buf2, length)
2057 ** $_streq(str1, str2)
2059 ** $_regex(str, regex)
2061 * The 'cd' command now defaults to using '~' (the home directory) if not
2064 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2065 default for GCC since November 2000.
2067 * The command 'forward-search' can now be abbreviated as 'fo'.
2069 * The command 'info tracepoints' can now display 'installed on target'
2070 or 'not installed on target' for each non-pending location of tracepoint.
2072 * New configure options
2074 --enable-libmcheck/--disable-libmcheck
2075 By default, development versions are built with -lmcheck on hosts
2076 that support it, in order to help track memory corruption issues.
2077 Release versions, on the other hand, are built without -lmcheck
2078 by default. The --enable-libmcheck/--disable-libmcheck configure
2079 options allow the user to override that default.
2080 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2081 This configure option allows the user to build GDB with
2082 libbabeltrace using which GDB can read Common Trace Format data.
2084 * New commands (for set/show, see "New options" below)
2087 Catch signals. This is similar to "handle", but allows commands and
2088 conditions to be attached.
2091 List the BFDs known to GDB.
2093 python-interactive [command]
2095 Start a Python interactive prompt, or evaluate the optional command
2096 and print the result of expressions.
2099 "py" is a new alias for "python".
2101 enable type-printer [name]...
2102 disable type-printer [name]...
2103 Enable or disable type printers.
2107 ** For the Renesas Super-H architecture, the "regs" command has been removed
2108 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2113 set print type methods (on|off)
2114 show print type methods
2115 Control whether method declarations are displayed by "ptype".
2116 The default is to show them.
2118 set print type typedefs (on|off)
2119 show print type typedefs
2120 Control whether typedef definitions are displayed by "ptype".
2121 The default is to show them.
2123 set filename-display basename|relative|absolute
2124 show filename-display
2125 Control the way in which filenames is displayed.
2126 The default is "relative", which preserves previous behavior.
2128 set trace-buffer-size
2129 show trace-buffer-size
2130 Request target to change the size of trace buffer.
2132 set remote trace-buffer-size-packet auto|on|off
2133 show remote trace-buffer-size-packet
2134 Control the use of the remote protocol `QTBuffer:size' packet.
2138 Control display of debugging messages related to ARM AArch64.
2141 set debug coff-pe-read
2142 show debug coff-pe-read
2143 Control display of debugging messages related to reading of COFF/PE
2148 Control display of debugging messages related to Mach-O symbols
2151 set debug notification
2152 show debug notification
2153 Control display of debugging info for async remote notification.
2157 ** Command parameter changes are now notified using new async record
2158 "=cmd-param-changed".
2159 ** Trace frame changes caused by command "tfind" are now notified using
2160 new async record "=traceframe-changed".
2161 ** The creation, deletion and modification of trace state variables
2162 are now notified using new async records "=tsv-created",
2163 "=tsv-deleted" and "=tsv-modified".
2164 ** The start and stop of process record are now notified using new
2165 async record "=record-started" and "=record-stopped".
2166 ** Memory changes are now notified using new async record
2168 ** The data-disassemble command response will include a "fullname" field
2169 containing the absolute file name when source has been requested.
2170 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2171 command, to allow pattern filling of memory areas.
2172 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2173 library load/unload events.
2174 ** The response to breakpoint commands and breakpoint async records
2175 includes an "installed" field containing a boolean state about each
2176 non-pending tracepoint location is whether installed on target or not.
2177 ** Output of the "-trace-status" command includes a "trace-file" field
2178 containing the name of the trace file being examined. This field is
2179 optional, and only present when examining a trace file.
2180 ** The "fullname" field is now always present along with the "file" field,
2181 even if the file cannot be found by GDB.
2183 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2184 You must have the LZMA library available when configuring GDB for this
2185 feature to be enabled. For more information, see:
2186 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2188 * New remote packets
2191 Set the size of trace buffer. The remote stub reports support for this
2192 packet to gdb's qSupported query.
2195 Enable Branch Trace Store (BTS)-based branch tracing for the current
2196 thread. The remote stub reports support for this packet to gdb's
2200 Disable branch tracing for the current thread. The remote stub reports
2201 support for this packet to gdb's qSupported query.
2204 Read the traced branches for the current thread. The remote stub
2205 reports support for this packet to gdb's qSupported query.
2207 *** Changes in GDB 7.5
2209 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2210 for more x32 ABI info.
2212 * GDB now supports access to MIPS DSP registers on Linux targets.
2214 * GDB now supports debugging microMIPS binaries.
2216 * The "info os" command on GNU/Linux can now display information on
2217 several new classes of objects managed by the operating system:
2218 "info os procgroups" lists process groups
2219 "info os files" lists file descriptors
2220 "info os sockets" lists internet-domain sockets
2221 "info os shm" lists shared-memory regions
2222 "info os semaphores" lists semaphores
2223 "info os msg" lists message queues
2224 "info os modules" lists loaded kernel modules
2226 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2227 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2228 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2229 options and inspect the probe arguments using the new $_probe_arg family
2230 of convenience variables. You can obtain more information about SystemTap
2231 in <http://sourceware.org/systemtap/>.
2233 * GDB now supports reversible debugging on ARM, it allows you to
2234 debug basic ARM and THUMB instructions, and provides
2235 record/replay support.
2237 * The option "symbol-reloading" has been deleted as it is no longer used.
2241 ** GDB commands implemented in Python can now be put in command class
2244 ** The "maint set python print-stack on|off" is now deleted.
2246 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2247 apply "flag enum"-style pretty-printing to any enum.
2249 ** gdb.lookup_symbol can now work when there is no current frame.
2251 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2252 the source at which the symbol was defined.
2254 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2255 method 'value'. The former indicates whether the symbol needs a
2256 frame in order to compute its value, and the latter computes the
2259 ** A new method 'referenced_value' on gdb.Value objects which can
2260 dereference pointer as well as C++ reference values.
2262 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2263 which return the global and static blocks (as gdb.Block objects),
2264 of the underlying symbol table, respectively.
2266 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2267 object associated with a PC value.
2269 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2270 of the address range occupied by code for the current source line.
2272 * Go language support.
2273 GDB now supports debugging programs written in the Go programming
2276 * GDBserver now supports stdio connections.
2277 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2279 * The binary "gdbtui" can no longer be built or installed.
2280 Use "gdb -tui" instead.
2282 * GDB will now print "flag" enums specially. A flag enum is one where
2283 all the enumerator values have no bits in common when pairwise
2284 "and"ed. When printing a value whose type is a flag enum, GDB will
2285 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2286 (gdb) print (enum E) 3
2289 * The filename part of a linespec will now match trailing components
2290 of a source file name. For example, "break gcc/expr.c:1000" will
2291 now set a breakpoint in build/gcc/expr.c, but not
2292 build/libcpp/expr.c.
2294 * The "info proc" and "generate-core-file" commands will now also
2295 work on remote targets connected to GDBserver on Linux.
2297 * The command "info catch" has been removed. It has been disabled
2298 since December 2007.
2300 * The "catch exception" and "catch assert" commands now accept
2301 a condition at the end of the command, much like the "break"
2302 command does. For instance:
2304 (gdb) catch exception Constraint_Error if Barrier = True
2306 Previously, it was possible to add a condition to such catchpoints,
2307 but it had to be done as a second step, after the catchpoint had been
2308 created, using the "condition" command.
2310 * The "info static-tracepoint-marker" command will now also work on
2311 native Linux targets with in-process agent.
2313 * GDB can now set breakpoints on inlined functions.
2315 * The .gdb_index section has been updated to include symbols for
2316 inlined functions. GDB will ignore older .gdb_index sections by
2317 default, which could cause symbol files to be loaded more slowly
2318 until their .gdb_index sections can be recreated. The new command
2319 "set use-deprecated-index-sections on" will cause GDB to use any older
2320 .gdb_index sections it finds. This will restore performance, but the
2321 ability to set breakpoints on inlined functions will be lost in symbol
2322 files with older .gdb_index sections.
2324 The .gdb_index section has also been updated to record more information
2325 about each symbol. This speeds up the "info variables", "info functions"
2326 and "info types" commands when used with programs having the .gdb_index
2327 section, as well as speeding up debugging with shared libraries using
2328 the .gdb_index section.
2330 * Ada support for GDB/MI Variable Objects has been added.
2332 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2337 ** New command -info-os is the MI equivalent of "info os".
2339 ** Output logs ("set logging" and related) now include MI output.
2343 ** "set use-deprecated-index-sections on|off"
2344 "show use-deprecated-index-sections on|off"
2345 Controls the use of deprecated .gdb_index sections.
2347 ** "catch load" and "catch unload" can be used to stop when a shared
2348 library is loaded or unloaded, respectively.
2350 ** "enable count" can be used to auto-disable a breakpoint after
2353 ** "info vtbl" can be used to show the virtual method tables for
2354 C++ and Java objects.
2356 ** "explore" and its sub commands "explore value" and "explore type"
2357 can be used to recursively explore values and types of
2358 expressions. These commands are available only if GDB is
2359 configured with '--with-python'.
2361 ** "info auto-load" shows status of all kinds of auto-loaded files,
2362 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2363 sequences of commands files, "info auto-load python-scripts"
2364 shows status of auto-loading Python script files,
2365 "info auto-load local-gdbinit" shows status of loading init file
2366 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2367 status of inferior specific thread debugging shared library loading.
2369 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2370 and "show auto-load-scripts" commands have been deprecated, use their
2371 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2372 and "show auto-load python-scripts" counterparts instead.
2374 ** "dprintf location,format,args..." creates a dynamic printf, which
2375 is basically a breakpoint that does a printf and immediately
2376 resumes your program's execution, so it is like a printf that you
2377 can insert dynamically at runtime instead of at compiletime.
2379 ** "set print symbol"
2381 Controls whether GDB attempts to display the symbol, if any,
2382 corresponding to addresses it prints. This defaults to "on", but
2383 you can set it to "off" to restore GDB's previous behavior.
2385 * Deprecated commands
2387 ** For the Renesas Super-H architecture, the "regs" command has been
2388 deprecated, and "info all-registers" should be used instead.
2392 Renesas RL78 rl78-*-elf
2393 HP OpenVMS ia64 ia64-hp-openvms*
2395 * GDBserver supports evaluation of breakpoint conditions. When
2396 support is advertised by GDBserver, GDB may be told to send the
2397 breakpoint conditions in bytecode form to GDBserver. GDBserver
2398 will only report the breakpoint trigger to GDB when its condition
2403 set mips compression
2404 show mips compression
2405 Select the compressed ISA encoding used in functions that have no symbol
2406 information available. The encoding can be set to either of:
2409 and is updated automatically from ELF file flags if available.
2411 set breakpoint condition-evaluation
2412 show breakpoint condition-evaluation
2413 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2414 GDBserver ("target"). Default option "auto" chooses the most efficient
2416 This option can improve debugger efficiency depending on the speed of the
2420 Disable auto-loading globally.
2423 Show auto-loading setting of all kinds of auto-loaded files.
2425 set auto-load gdb-scripts on|off
2426 show auto-load gdb-scripts
2427 Control auto-loading of GDB canned sequences of commands files.
2429 set auto-load python-scripts on|off
2430 show auto-load python-scripts
2431 Control auto-loading of Python script files.
2433 set auto-load local-gdbinit on|off
2434 show auto-load local-gdbinit
2435 Control loading of init file (.gdbinit) from current directory.
2437 set auto-load libthread-db on|off
2438 show auto-load libthread-db
2439 Control auto-loading of inferior specific thread debugging shared library.
2441 set auto-load scripts-directory <dir1>[:<dir2>...]
2442 show auto-load scripts-directory
2443 Set a list of directories from which to load auto-loaded scripts.
2444 Automatically loaded Python scripts and GDB scripts are located in one
2445 of the directories listed by this option.
2446 The delimiter (':' above) may differ according to the host platform.
2448 set auto-load safe-path <dir1>[:<dir2>...]
2449 show auto-load safe-path
2450 Set a list of directories from which it is safe to auto-load files.
2451 The delimiter (':' above) may differ according to the host platform.
2453 set debug auto-load on|off
2454 show debug auto-load
2455 Control display of debugging info for auto-loading the files above.
2457 set dprintf-style gdb|call|agent
2459 Control the way in which a dynamic printf is performed; "gdb"
2460 requests a GDB printf command, while "call" causes dprintf to call a
2461 function in the inferior. "agent" requests that the target agent
2462 (such as GDBserver) do the printing.
2464 set dprintf-function <expr>
2465 show dprintf-function
2466 set dprintf-channel <expr>
2467 show dprintf-channel
2468 Set the function and optional first argument to the call when using
2469 the "call" style of dynamic printf.
2471 set disconnected-dprintf on|off
2472 show disconnected-dprintf
2473 Control whether agent-style dynamic printfs continue to be in effect
2474 after GDB disconnects.
2476 * New configure options
2478 --with-auto-load-dir
2479 Configure default value for the 'set auto-load scripts-directory'
2480 setting above. It defaults to '$debugdir:$datadir/auto-load',
2481 $debugdir representing global debugging info directories (available
2482 via 'show debug-file-directory') and $datadir representing GDB's data
2483 directory (available via 'show data-directory').
2485 --with-auto-load-safe-path
2486 Configure default value for the 'set auto-load safe-path' setting
2487 above. It defaults to the --with-auto-load-dir setting.
2489 --without-auto-load-safe-path
2490 Set 'set auto-load safe-path' to '/', effectively disabling this
2493 * New remote packets
2495 z0/z1 conditional breakpoints extension
2497 The z0/z1 breakpoint insertion packets have been extended to carry
2498 a list of conditional expressions over to the remote stub depending on the
2499 condition evaluation mode. The use of this extension can be controlled
2500 via the "set remote conditional-breakpoints-packet" command.
2504 Specify the signals which the remote stub may pass to the debugged
2505 program without GDB involvement.
2507 * New command line options
2509 --init-command=FILE, -ix Like --command, -x but execute it
2510 before loading inferior.
2511 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2512 execute it before loading inferior.
2514 *** Changes in GDB 7.4
2516 * GDB now handles ambiguous linespecs more consistently; the existing
2517 FILE:LINE support has been expanded to other types of linespecs. A
2518 breakpoint will now be set on all matching locations in all
2519 inferiors, and locations will be added or removed according to
2522 * GDB now allows you to skip uninteresting functions and files when
2523 stepping with the "skip function" and "skip file" commands.
2525 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2526 and "show remote hardware-watchpoint-length-limit". These allows to
2527 set or show the maximum length limit (in bytes) of a remote
2528 target hardware watchpoint.
2530 This allows e.g. to use "unlimited" hardware watchpoints with the
2531 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2532 watchpoints are slower than real hardware watchpoints but are
2533 significantly faster than gdb software watchpoints.
2537 ** The register_pretty_printer function in module gdb.printing now takes
2538 an optional `replace' argument. If True, the new printer replaces any
2541 ** The "maint set python print-stack on|off" command has been
2542 deprecated and will be deleted in GDB 7.5.
2543 A new command: "set python print-stack none|full|message" has
2544 replaced it. Additionally, the default for "print-stack" is
2545 now "message", which just prints the error message without
2548 ** A prompt substitution hook (prompt_hook) is now available to the
2551 ** A new Python module, gdb.prompt has been added to the GDB Python
2552 modules library. This module provides functionality for
2553 escape sequences in prompts (used by set/show
2554 extended-prompt). These escape sequences are replaced by their
2555 corresponding value.
2557 ** Python commands and convenience-functions located in
2558 'data-directory'/python/gdb/command and
2559 'data-directory'/python/gdb/function are now automatically loaded
2562 ** Blocks now provide four new attributes. global_block and
2563 static_block will return the global and static blocks
2564 respectively. is_static and is_global are boolean attributes
2565 that indicate if the block is one of those two types.
2567 ** Symbols now provide the "type" attribute, the type of the symbol.
2569 ** The "gdb.breakpoint" function has been deprecated in favor of
2572 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2573 of a function. This class is based on the "finish" command
2574 available in the CLI.
2576 ** Type objects for struct and union types now allow access to
2577 the fields using standard Python dictionary (mapping) methods.
2578 For example, "some_type['myfield']" now works, as does
2579 "some_type.items()".
2581 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2584 ** A new function, "deep_items" has been added to the gdb.types
2585 module in the GDB Python modules library. This function returns
2586 an iterator over the fields of a struct or union type. Unlike
2587 the standard Python "iteritems" method, it will recursively traverse
2588 any anonymous fields.
2592 ** "*stopped" events can report several new "reason"s, such as
2595 ** Breakpoint changes are now notified using new async records, like
2596 "=breakpoint-modified".
2598 ** New command -ada-task-info.
2600 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2601 $sdir specifies the default system locations of shared libraries.
2602 $pdir specifies the directory where the libpthread used by the application
2605 GDB no longer looks in $sdir and $pdir after it has searched the directories
2606 mentioned in libthread-db-search-path. If you want to search those
2607 directories, they must be specified in libthread-db-search-path.
2608 The default value of libthread-db-search-path on GNU/Linux and Solaris
2609 systems is now "$sdir:$pdir".
2611 $pdir is not supported by gdbserver, it is currently ignored.
2612 $sdir is supported by gdbserver.
2614 * New configure option --with-iconv-bin.
2615 When using the internationalization support like the one in the GNU C
2616 library, GDB will invoke the "iconv" program to get a list of supported
2617 character sets. If this program lives in a non-standard location, one can
2618 use this option to specify where to find it.
2620 * When natively debugging programs on PowerPC BookE processors running
2621 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2622 watchpoints, which specify a mask in addition to an address to watch.
2623 The mask specifies that some bits of an address (the bits which are
2624 reset in the mask) should be ignored when matching the address accessed
2625 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2626 section in the user manual for more details.
2628 * The new option --once causes GDBserver to stop listening for connections once
2629 the first connection is made. The listening port used by GDBserver will
2630 become available after that.
2632 * New commands "info macros" and "alias" have been added.
2634 * New function parameters suffix @entry specifies value of function parameter
2635 at the time the function got called. Entry values are available only since
2641 "!" is now an alias of the "shell" command.
2642 Note that no space is needed between "!" and SHELL COMMAND.
2646 watch EXPRESSION mask MASK_VALUE
2647 The watch command now supports the mask argument which allows creation
2648 of masked watchpoints, if the current architecture supports this feature.
2650 info auto-load-scripts [REGEXP]
2651 This command was formerly named "maintenance print section-scripts".
2652 It is now generally useful and is no longer a maintenance-only command.
2654 info macro [-all] [--] MACRO
2655 The info macro command has new options `-all' and `--'. The first for
2656 printing all definitions of a macro. The second for explicitly specifying
2657 the end of arguments and the beginning of the macro name in case the macro
2658 name starts with a hyphen.
2660 collect[/s] EXPRESSIONS
2661 The tracepoint collect command now takes an optional modifier "/s"
2662 that directs it to dereference pointer-to-character types and
2663 collect the bytes of memory up to a zero byte. The behavior is
2664 similar to what you see when you use the regular print command on a
2665 string. An optional integer following the "/s" sets a bound on the
2666 number of bytes that will be collected.
2669 The trace start command now interprets any supplied arguments as a
2670 note to be recorded with the trace run, with an effect similar to
2671 setting the variable trace-notes.
2674 The trace stop command now interprets any arguments as a note to be
2675 mentioned along with the tstatus report that the trace was stopped
2676 with a command. The effect is similar to setting the variable
2679 * Tracepoints can now be enabled and disabled at any time after a trace
2680 experiment has been started using the standard "enable" and "disable"
2681 commands. It is now possible to start a trace experiment with no enabled
2682 tracepoints; GDB will display a warning, but will allow the experiment to
2683 begin, assuming that tracepoints will be enabled as needed while the trace
2686 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2687 locations with 4-byte instructions, when they were previously
2688 limited to locations with instructions of 5 bytes or longer.
2692 set debug dwarf2-read
2693 show debug dwarf2-read
2694 Turns on or off display of debugging messages related to reading
2695 DWARF debug info. The default is off.
2697 set debug symtab-create
2698 show debug symtab-create
2699 Turns on or off display of debugging messages related to symbol table
2700 creation. The default is off.
2703 show extended-prompt
2704 Set the GDB prompt, and allow escape sequences to be inserted to
2705 display miscellaneous information (see 'help set extended-prompt'
2706 for the list of sequences). This prompt (and any information
2707 accessed through the escape sequences) is updated every time the
2708 prompt is displayed.
2710 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2711 show print entry-values
2712 Set printing of frame argument values at function entry. In some cases
2713 GDB can determine the value of function argument which was passed by the
2714 function caller, even if the value was modified inside the called function.
2716 set debug entry-values
2717 show debug entry-values
2718 Control display of debugging info for determining frame argument values at
2719 function entry and virtual tail call frames.
2721 set basenames-may-differ
2722 show basenames-may-differ
2723 Set whether a source file may have multiple base names.
2724 (A "base name" is the name of a file with the directory part removed.
2725 Example: The base name of "/home/user/hello.c" is "hello.c".)
2726 If set, GDB will canonicalize file names (e.g., expand symlinks)
2727 before comparing them. Canonicalization is an expensive operation,
2728 but it allows the same file be known by more than one base name.
2729 If not set (the default), all source files are assumed to have just
2730 one base name, and gdb will do file name comparisons more efficiently.
2736 Set a user name and notes for the current and any future trace runs.
2737 This is useful for long-running and/or disconnected traces, to
2738 inform others (or yourself) as to who is running the trace, supply
2739 contact information, or otherwise explain what is going on.
2741 set trace-stop-notes
2742 show trace-stop-notes
2743 Set a note attached to the trace run, that is displayed when the
2744 trace has been stopped by a tstop command. This is useful for
2745 instance as an explanation, if you are stopping a trace run that was
2746 started by someone else.
2748 * New remote packets
2752 Dynamically enable a tracepoint in a started trace experiment.
2756 Dynamically disable a tracepoint in a started trace experiment.
2760 Set the user and notes of the trace run.
2764 Query the current status of a tracepoint.
2768 Query the minimum length of instruction at which a fast tracepoint may
2771 * Dcache size (number of lines) and line-size are now runtime-configurable
2772 via "set dcache line" and "set dcache line-size" commands.
2776 Texas Instruments TMS320C6x tic6x-*-*
2780 Renesas RL78 rl78-*-elf
2782 *** Changes in GDB 7.3.1
2784 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2786 *** Changes in GDB 7.3
2788 * GDB has a new command: "thread find [REGEXP]".
2789 It finds the thread id whose name, target id, or thread extra info
2790 matches the given regular expression.
2792 * The "catch syscall" command now works on mips*-linux* targets.
2794 * The -data-disassemble MI command now supports modes 2 and 3 for
2795 dumping the instruction opcodes.
2797 * New command line options
2799 -data-directory DIR Specify DIR as the "data-directory".
2800 This is mostly for testing purposes.
2802 * The "maint set python auto-load on|off" command has been renamed to
2803 "set auto-load-scripts on|off".
2805 * GDB has a new command: "set directories".
2806 It is like the "dir" command except that it replaces the
2807 source path list instead of augmenting it.
2809 * GDB now understands thread names.
2811 On GNU/Linux, "info threads" will display the thread name as set by
2812 prctl or pthread_setname_np.
2814 There is also a new command, "thread name", which can be used to
2815 assign a name internally for GDB to display.
2818 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2819 has been integrated into GDB.
2823 ** The function gdb.Write now accepts an optional keyword 'stream'.
2824 This keyword, when provided, will direct the output to either
2825 stdout, stderr, or GDB's logging output.
2827 ** Parameters can now be be sub-classed in Python, and in particular
2828 you may implement the get_set_doc and get_show_doc functions.
2829 This improves how Parameter set/show documentation is processed
2830 and allows for more dynamic content.
2832 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2833 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2834 have an is_valid method.
2836 ** Breakpoints can now be sub-classed in Python, and in particular
2837 you may implement a 'stop' function that is executed each time
2838 the inferior reaches that breakpoint.
2840 ** New function gdb.lookup_global_symbol looks up a global symbol.
2842 ** GDB values in Python are now callable if the value represents a
2843 function. For example, if 'some_value' represents a function that
2844 takes two integer parameters and returns a value, you can call
2845 that function like so:
2847 result = some_value (10,20)
2849 ** Module gdb.types has been added.
2850 It contains a collection of utilities for working with gdb.Types objects:
2851 get_basic_type, has_field, make_enum_dict.
2853 ** Module gdb.printing has been added.
2854 It contains utilities for writing and registering pretty-printers.
2855 New classes: PrettyPrinter, SubPrettyPrinter,
2856 RegexpCollectionPrettyPrinter.
2857 New function: register_pretty_printer.
2859 ** New commands "info pretty-printers", "enable pretty-printer" and
2860 "disable pretty-printer" have been added.
2862 ** gdb.parameter("directories") is now available.
2864 ** New function gdb.newest_frame returns the newest frame in the
2867 ** The gdb.InferiorThread class has a new "name" attribute. This
2868 holds the thread's name.
2870 ** Python Support for Inferior events.
2871 Python scripts can add observers to be notified of events
2872 occurring in the process being debugged.
2873 The following events are currently supported:
2874 - gdb.events.cont Continue event.
2875 - gdb.events.exited Inferior exited event.
2876 - gdb.events.stop Signal received, and Breakpoint hit events.
2880 ** GDB now puts template parameters in scope when debugging in an
2881 instantiation. For example, if you have:
2883 template<int X> int func (void) { return X; }
2885 then if you step into func<5>, "print X" will show "5". This
2886 feature requires proper debuginfo support from the compiler; it
2887 was added to GCC 4.5.
2889 ** The motion commands "next", "finish", "until", and "advance" now
2890 work better when exceptions are thrown. In particular, GDB will
2891 no longer lose control of the inferior; instead, the GDB will
2892 stop the inferior at the point at which the exception is caught.
2893 This functionality requires a change in the exception handling
2894 code that was introduced in GCC 4.5.
2896 * GDB now follows GCC's rules on accessing volatile objects when
2897 reading or writing target state during expression evaluation.
2898 One notable difference to prior behavior is that "print x = 0"
2899 no longer generates a read of x; the value of the assignment is
2900 now always taken directly from the value being assigned.
2902 * GDB now has some support for using labels in the program's source in
2903 linespecs. For instance, you can use "advance label" to continue
2904 execution to a label.
2906 * GDB now has support for reading and writing a new .gdb_index
2907 section. This section holds a fast index of DWARF debugging
2908 information and can be used to greatly speed up GDB startup and
2909 operation. See the documentation for `save gdb-index' for details.
2911 * The "watch" command now accepts an optional "-location" argument.
2912 When used, this causes GDB to watch the memory referred to by the
2913 expression. Such a watchpoint is never deleted due to it going out
2916 * GDB now supports thread debugging of core dumps on GNU/Linux.
2918 GDB now activates thread debugging using the libthread_db library
2919 when debugging GNU/Linux core dumps, similarly to when debugging
2920 live processes. As a result, when debugging a core dump file, GDB
2921 is now able to display pthread_t ids of threads. For example, "info
2922 threads" shows the same output as when debugging the process when it
2923 was live. In earlier releases, you'd see something like this:
2926 * 1 LWP 6780 main () at main.c:10
2928 While now you see this:
2931 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2933 It is also now possible to inspect TLS variables when debugging core
2936 When debugging a core dump generated on a machine other than the one
2937 used to run GDB, you may need to point GDB at the correct
2938 libthread_db library with the "set libthread-db-search-path"
2939 command. See the user manual for more details on this command.
2941 * When natively debugging programs on PowerPC BookE processors running
2942 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2943 which stop execution of the inferior whenever it executes an instruction
2944 at any address within the specified range. See the "PowerPC Embedded"
2945 section in the user manual for more details.
2947 * New features in the GDB remote stub, GDBserver
2949 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2950 and i686 LynxOS (version 5.x).
2952 ** GDBserver is now supported on Blackfin Linux.
2954 * New native configurations
2956 ia64 HP-UX ia64-*-hpux*
2960 Analog Devices, Inc. Blackfin Processor bfin-*
2962 * Ada task switching is now supported on sparc-elf targets when
2963 debugging a program using the Ravenscar Profile. For more information,
2964 see the "Tasking Support when using the Ravenscar Profile" section
2965 in the GDB user manual.
2967 * Guile support was removed.
2969 * New features in the GNU simulator
2971 ** The --map-info flag lists all known core mappings.
2973 ** CFI flashes may be simulated via the "cfi" device.
2975 *** Changes in GDB 7.2
2977 * Shared library support for remote targets by default
2979 When GDB is configured for a generic, non-OS specific target, like
2980 for example, --target=arm-eabi or one of the many *-*-elf targets,
2981 GDB now queries remote stubs for loaded shared libraries using the
2982 `qXfer:libraries:read' packet. Previously, shared library support
2983 was always disabled for such configurations.
2987 ** Argument Dependent Lookup (ADL)
2989 In C++ ADL lookup directs function search to the namespaces of its
2990 arguments even if the namespace has not been imported.
3000 Here the compiler will search for `foo' in the namespace of 'b'
3001 and find A::foo. GDB now supports this. This construct is commonly
3002 used in the Standard Template Library for operators.
3004 ** Improved User Defined Operator Support
3006 In addition to member operators, GDB now supports lookup of operators
3007 defined in a namespace and imported with a `using' directive, operators
3008 defined in the global scope, operators imported implicitly from an
3009 anonymous namespace, and the ADL operators mentioned in the previous
3011 GDB now also supports proper overload resolution for all the previously
3012 mentioned flavors of operators.
3014 ** static const class members
3016 Printing of static const class members that are initialized in the
3017 class definition has been fixed.
3019 * Windows Thread Information Block access.
3021 On Windows targets, GDB now supports displaying the Windows Thread
3022 Information Block (TIB) structure. This structure is visible either
3023 by using the new command `info w32 thread-information-block' or, by
3024 dereferencing the new convenience variable named `$_tlb', a
3025 thread-specific pointer to the TIB. This feature is also supported
3026 when remote debugging using GDBserver.
3028 * Static tracepoints
3030 Static tracepoints are calls in the user program into a tracing
3031 library. One such library is a port of the LTTng kernel tracer to
3032 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3033 When debugging with GDBserver, GDB now supports combining the GDB
3034 tracepoint machinery with such libraries. For example: the user can
3035 use GDB to probe a static tracepoint marker (a call from the user
3036 program into the tracing library) with the new "strace" command (see
3037 "New commands" below). This creates a "static tracepoint" in the
3038 breakpoint list, that can be manipulated with the same feature set
3039 as fast and regular tracepoints. E.g., collect registers, local and
3040 global variables, collect trace state variables, and define
3041 tracepoint conditions. In addition, the user can collect extra
3042 static tracepoint marker specific data, by collecting the new
3043 $_sdata internal variable. When analyzing the trace buffer, you can
3044 inspect $_sdata like any other variable available to GDB. For more
3045 information, see the "Tracepoints" chapter in GDB user manual. New
3046 remote packets have been defined to support static tracepoints, see
3047 the "New remote packets" section below.
3049 * Better reconstruction of tracepoints after disconnected tracing
3051 GDB will attempt to download the original source form of tracepoint
3052 definitions when starting a trace run, and then will upload these
3053 upon reconnection to the target, resulting in a more accurate
3054 reconstruction of the tracepoints that are in use on the target.
3058 You can now exercise direct control over the ways that GDB can
3059 affect your program. For instance, you can disallow the setting of
3060 breakpoints, so that the program can run continuously (assuming
3061 non-stop mode). In addition, the "observer" variable is available
3062 to switch all of the different controls; in observer mode, GDB
3063 cannot affect the target's behavior at all, which is useful for
3064 tasks like diagnosing live systems in the field.
3066 * The new convenience variable $_thread holds the number of the
3069 * New remote packets
3073 Return the address of the Windows Thread Information Block of a given thread.
3077 In response to several of the tracepoint packets, the target may now
3078 also respond with a number of intermediate `qRelocInsn' request
3079 packets before the final result packet, to have GDB handle
3080 relocating an instruction to execute at a different address. This
3081 is particularly useful for stubs that support fast tracepoints. GDB
3082 reports support for this feature in the qSupported packet.
3086 List static tracepoint markers in the target program.
3090 List static tracepoint markers at a given address in the target
3093 qXfer:statictrace:read
3095 Read the static trace data collected (by a `collect $_sdata'
3096 tracepoint action). The remote stub reports support for this packet
3097 to gdb's qSupported query.
3101 Send the current settings of GDB's permission flags.
3105 Send part of the source (textual) form of a tracepoint definition,
3106 which includes location, conditional, and action list.
3108 * The source command now accepts a -s option to force searching for the
3109 script in the source search path even if the script name specifies
3112 * New features in the GDB remote stub, GDBserver
3114 - GDBserver now support tracepoints (including fast tracepoints, and
3115 static tracepoints). The feature is currently supported by the
3116 i386-linux and amd64-linux builds. See the "Tracepoints support
3117 in gdbserver" section in the manual for more information.
3119 GDBserver JIT compiles the tracepoint's conditional agent
3120 expression bytecode into native code whenever possible for low
3121 overhead dynamic tracepoints conditionals. For such tracepoints,
3122 an expression that examines program state is evaluated when the
3123 tracepoint is reached, in order to determine whether to capture
3124 trace data. If the condition is simple and false, processing the
3125 tracepoint finishes very quickly and no data is gathered.
3127 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3128 for static tracepoints support.
3130 - GDBserver now supports x86_64 Windows 64-bit debugging.
3132 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3133 it understands register description.
3135 * The --batch flag now disables pagination and queries.
3137 * X86 general purpose registers
3139 GDB now supports reading/writing byte, word and double-word x86
3140 general purpose registers directly. This means you can use, say,
3141 $ah or $ax to refer, respectively, to the byte register AH and
3142 16-bit word register AX that are actually portions of the 32-bit
3143 register EAX or 64-bit register RAX.
3145 * The `commands' command now accepts a range of breakpoints to modify.
3146 A plain `commands' following a command that creates multiple
3147 breakpoints affects all the breakpoints set by that command. This
3148 applies to breakpoints set by `rbreak', and also applies when a
3149 single `break' command creates multiple breakpoints (e.g.,
3150 breakpoints on overloaded c++ functions).
3152 * The `rbreak' command now accepts a filename specification as part of
3153 its argument, limiting the functions selected by the regex to those
3154 in the specified file.
3156 * Support for remote debugging Windows and SymbianOS shared libraries
3157 from Unix hosts has been improved. Non Windows GDB builds now can
3158 understand target reported file names that follow MS-DOS based file
3159 system semantics, such as file names that include drive letters and
3160 use the backslash character as directory separator. This makes it
3161 possible to transparently use the "set sysroot" and "set
3162 solib-search-path" on Unix hosts to point as host copies of the
3163 target's shared libraries. See the new command "set
3164 target-file-system-kind" described below, and the "Commands to
3165 specify files" section in the user manual for more information.
3169 eval template, expressions...
3170 Convert the values of one or more expressions under the control
3171 of the string template to a command line, and call it.
3173 set target-file-system-kind unix|dos-based|auto
3174 show target-file-system-kind
3175 Set or show the assumed file system kind for target reported file
3178 save breakpoints <filename>
3179 Save all current breakpoint definitions to a file suitable for use
3180 in a later debugging session. To read the saved breakpoint
3181 definitions, use the `source' command.
3183 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3186 info static-tracepoint-markers
3187 Display information about static tracepoint markers in the target.
3189 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3190 Define a static tracepoint by probing a marker at the given
3191 function, line, address, or marker ID.
3195 Enable and disable observer mode.
3197 set may-write-registers on|off
3198 set may-write-memory on|off
3199 set may-insert-breakpoints on|off
3200 set may-insert-tracepoints on|off
3201 set may-insert-fast-tracepoints on|off
3202 set may-interrupt on|off
3203 Set individual permissions for GDB effects on the target. Note that
3204 some of these settings can have undesirable or surprising
3205 consequences, particularly when changed in the middle of a session.
3206 For instance, disabling the writing of memory can prevent
3207 breakpoints from being inserted, cause single-stepping to fail, or
3208 even crash your program, if you disable after breakpoints have been
3209 inserted. However, GDB should not crash.
3211 set record memory-query on|off
3212 show record memory-query
3213 Control whether to stop the inferior if memory changes caused
3214 by an instruction cannot be recorded.
3219 The disassemble command now supports "start,+length" form of two arguments.
3223 ** GDB now provides a new directory location, called the python directory,
3224 where Python scripts written for GDB can be installed. The location
3225 of that directory is <data-directory>/python, where <data-directory>
3226 is the GDB data directory. For more details, see section `Scripting
3227 GDB using Python' in the manual.
3229 ** The GDB Python API now has access to breakpoints, symbols, symbol
3230 tables, program spaces, inferiors, threads and frame's code blocks.
3231 Additionally, GDB Parameters can now be created from the API, and
3232 manipulated via set/show in the CLI.
3234 ** New functions gdb.target_charset, gdb.target_wide_charset,
3235 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3237 ** New exception gdb.GdbError.
3239 ** Pretty-printers are now also looked up in the current program space.
3241 ** Pretty-printers can now be individually enabled and disabled.
3243 ** GDB now looks for names of Python scripts to auto-load in a
3244 special section named `.debug_gdb_scripts', in addition to looking
3245 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3247 * Tracepoint actions were unified with breakpoint commands. In particular,
3248 there are no longer differences in "info break" output for breakpoints and
3249 tracepoints and the "commands" command can be used for both tracepoints and
3250 regular breakpoints.
3254 ARM Symbian arm*-*-symbianelf*
3256 * D language support.
3257 GDB now supports debugging programs written in the D programming
3260 * GDB now supports the extended ptrace interface for PowerPC which is
3261 available since Linux kernel version 2.6.34. This automatically enables
3262 any hardware breakpoints and additional hardware watchpoints available in
3263 the processor. The old ptrace interface exposes just one hardware
3264 watchpoint and no hardware breakpoints.
3266 * GDB is now able to use the Data Value Compare (DVC) register available on
3267 embedded PowerPC processors to implement in hardware simple watchpoint
3268 conditions of the form:
3270 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3272 This works in native GDB running on Linux kernels with the extended ptrace
3273 interface mentioned above.
3275 *** Changes in GDB 7.1
3279 ** Namespace Support
3281 GDB now supports importing of namespaces in C++. This enables the
3282 user to inspect variables from imported namespaces. Support for
3283 namepace aliasing has also been added. So, if a namespace is
3284 aliased in the current scope (e.g. namepace C=A; ) the user can
3285 print variables using the alias (e.g. (gdb) print C::x).
3289 All known bugs relating to the printing of virtual base class were
3290 fixed. It is now possible to call overloaded static methods using a
3295 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3296 and reinterpret_cast<> are now handled by the C++ expression parser.
3300 Xilinx MicroBlaze microblaze-*-*
3305 Xilinx MicroBlaze microblaze
3308 * Multi-program debugging.
3310 GDB now has support for multi-program (a.k.a. multi-executable or
3311 multi-exec) debugging. This allows for debugging multiple inferiors
3312 simultaneously each running a different program under the same GDB
3313 session. See "Debugging Multiple Inferiors and Programs" in the
3314 manual for more information. This implied some user visible changes
3315 in the multi-inferior support. For example, "info inferiors" now
3316 lists inferiors that are not running yet or that have exited
3317 already. See also "New commands" and "New options" below.
3319 * New tracing features
3321 GDB's tracepoint facility now includes several new features:
3323 ** Trace state variables
3325 GDB tracepoints now include support for trace state variables, which
3326 are variables managed by the target agent during a tracing
3327 experiment. They are useful for tracepoints that trigger each
3328 other, so for instance one tracepoint can count hits in a variable,
3329 and then a second tracepoint has a condition that is true when the
3330 count reaches a particular value. Trace state variables share the
3331 $-syntax of GDB convenience variables, and can appear in both
3332 tracepoint actions and condition expressions. Use the "tvariable"
3333 command to create, and "info tvariables" to view; see "Trace State
3334 Variables" in the manual for more detail.
3338 GDB now includes an option for defining fast tracepoints, which
3339 targets may implement more efficiently, such as by installing a jump
3340 into the target agent rather than a trap instruction. The resulting
3341 speedup can be by two orders of magnitude or more, although the
3342 tradeoff is that some program locations on some target architectures
3343 might not allow fast tracepoint installation, for instance if the
3344 instruction to be replaced is shorter than the jump. To request a
3345 fast tracepoint, use the "ftrace" command, with syntax identical to
3346 the regular trace command.
3348 ** Disconnected tracing
3350 It is now possible to detach GDB from the target while it is running
3351 a trace experiment, then reconnect later to see how the experiment
3352 is going. In addition, a new variable disconnected-tracing lets you
3353 tell the target agent whether to continue running a trace if the
3354 connection is lost unexpectedly.
3358 GDB now has the ability to save the trace buffer into a file, and
3359 then use that file as a target, similarly to you can do with
3360 corefiles. You can select trace frames, print data that was
3361 collected in them, and use tstatus to display the state of the
3362 tracing run at the moment that it was saved. To create a trace
3363 file, use "tsave <filename>", and to use it, do "target tfile
3366 ** Circular trace buffer
3368 You can ask the target agent to handle the trace buffer as a
3369 circular buffer, discarding the oldest trace frames to make room for
3370 newer ones, by setting circular-trace-buffer to on. This feature may
3371 not be available for all target agents.
3376 The disassemble command, when invoked with two arguments, now requires
3377 the arguments to be comma-separated.
3380 The info variables command now displays variable definitions. Files
3381 which only declare a variable are not shown.
3384 The source command is now capable of sourcing Python scripts.
3385 This feature is dependent on the debugger being build with Python
3388 Related to this enhancement is also the introduction of a new command
3389 "set script-extension" (see below).
3391 * New commands (for set/show, see "New options" below)
3393 record save [<FILENAME>]
3394 Save a file (in core file format) containing the process record
3395 execution log for replay debugging at a later time.
3397 record restore <FILENAME>
3398 Restore the process record execution log that was saved at an
3399 earlier time, for replay debugging.
3401 add-inferior [-copies <N>] [-exec <FILENAME>]
3404 clone-inferior [-copies <N>] [ID]
3405 Make a new inferior ready to execute the same program another
3406 inferior has loaded.
3411 maint info program-spaces
3412 List the program spaces loaded into GDB.
3414 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3415 show remote interrupt-sequence
3416 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3417 as the sequence to the remote target in order to interrupt the execution.
3418 Ctrl-C is a default. Some system prefers BREAK which is high level of
3419 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3420 Magic SysRq g. It is BREAK signal and character 'g'.
3422 set remote interrupt-on-connect [on | off]
3423 show remote interrupt-on-connect
3424 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3425 remote target when gdb connects to it. This is needed when you debug
3428 set remotebreak [on | off]
3430 Deprecated. Use "set/show remote interrupt-sequence" instead.
3432 tvariable $NAME [ = EXP ]
3433 Create or modify a trace state variable.
3436 List trace state variables and their values.
3438 delete tvariable $NAME ...
3439 Delete one or more trace state variables.
3442 Evaluate the given expressions without collecting anything into the
3443 trace buffer. (Valid in tracepoint actions only.)
3445 ftrace FN / FILE:LINE / *ADDR
3446 Define a fast tracepoint at the given function, line, or address.
3448 * New expression syntax
3450 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3451 GDB now parses 0b101010 identically with 42.
3455 set follow-exec-mode new|same
3456 show follow-exec-mode
3457 Control whether GDB reuses the same inferior across an exec call or
3458 creates a new one. This is useful to be able to restart the old
3459 executable after the inferior having done an exec call.
3461 set default-collect EXPR, ...
3462 show default-collect
3463 Define a list of expressions to be collected at each tracepoint.
3464 This is a useful way to ensure essential items are not overlooked,
3465 such as registers or a critical global variable.
3467 set disconnected-tracing
3468 show disconnected-tracing
3469 If set to 1, the target is instructed to continue tracing if it
3470 loses its connection to GDB. If 0, the target is to stop tracing
3473 set circular-trace-buffer
3474 show circular-trace-buffer
3475 If set to on, the target is instructed to use a circular trace buffer
3476 and discard the oldest trace frames instead of stopping the trace due
3477 to a full trace buffer. If set to off, the trace stops when the buffer
3478 fills up. Some targets may not support this.
3480 set script-extension off|soft|strict
3481 show script-extension
3482 If set to "off", the debugger does not perform any script language
3483 recognition, and all sourced files are assumed to be GDB scripts.
3484 If set to "soft" (the default), files are sourced according to
3485 filename extension, falling back to GDB scripts if the first
3487 If set to "strict", files are sourced according to filename extension.
3489 set ada trust-PAD-over-XVS on|off
3490 show ada trust-PAD-over-XVS
3491 If off, activate a workaround against a bug in the debugging information
3492 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3493 the GCC sources for more information about the GNAT encoding and
3494 PAD types in particular). It is always safe to set this option to
3495 off, but this introduces a slight performance penalty. The default
3498 * Python API Improvements
3500 ** GDB provides the new class gdb.LazyString. This is useful in
3501 some pretty-printing cases. The new method gdb.Value.lazy_string
3502 provides a simple way to create objects of this type.
3504 ** The fields returned by gdb.Type.fields now have an
3505 `is_base_class' attribute.
3507 ** The new method gdb.Type.range returns the range of an array type.
3509 ** The new method gdb.parse_and_eval can be used to parse and
3510 evaluate an expression.
3512 * New remote packets
3515 Define a trace state variable.
3518 Get the current value of a trace state variable.
3521 Set desired tracing behavior upon disconnection.
3524 Set the trace buffer to be linear or circular.
3527 Get data about the tracepoints currently in use.
3531 Process record now works correctly with hardware watchpoints.
3533 Multiple bug fixes have been made to the mips-irix port, making it
3534 much more reliable. In particular:
3535 - Debugging threaded applications is now possible again. Previously,
3536 GDB would hang while starting the program, or while waiting for
3537 the program to stop at a breakpoint.
3538 - Attaching to a running process no longer hangs.
3539 - An error occurring while loading a core file has been fixed.
3540 - Changing the value of the PC register now works again. This fixes
3541 problems observed when using the "jump" command, or when calling
3542 a function from GDB, or even when assigning a new value to $pc.
3543 - With the "finish" and "return" commands, the return value for functions
3544 returning a small array is now correctly printed.
3545 - It is now possible to break on shared library code which gets executed
3546 during a shared library init phase (code executed while executing
3547 their .init section). Previously, the breakpoint would have no effect.
3548 - GDB is now able to backtrace through the signal handler for
3549 non-threaded programs.
3551 PIE (Position Independent Executable) programs debugging is now supported.
3552 This includes debugging execution of PIC (Position Independent Code) shared
3553 libraries although for that, it should be possible to run such libraries as an
3556 *** Changes in GDB 7.0
3558 * GDB now has an interface for JIT compilation. Applications that
3559 dynamically generate code can create symbol files in memory and register
3560 them with GDB. For users, the feature should work transparently, and
3561 for JIT developers, the interface is documented in the GDB manual in the
3562 "JIT Compilation Interface" chapter.
3564 * Tracepoints may now be conditional. The syntax is as for
3565 breakpoints; either an "if" clause appended to the "trace" command,
3566 or the "condition" command is available. GDB sends the condition to
3567 the target for evaluation using the same bytecode format as is used
3568 for tracepoint actions.
3570 * The disassemble command now supports: an optional /r modifier, print the
3571 raw instructions in hex as well as in symbolic form, and an optional /m
3572 modifier to print mixed source+assembly.
3574 * Process record and replay
3576 In a architecture environment that supports ``process record and
3577 replay'', ``process record and replay'' target can record a log of
3578 the process execution, and replay it with both forward and reverse
3581 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3582 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3583 set execution-direction {forward|reverse}, for targets that support
3586 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3587 feature is available with a native GDB running on kernel version
3590 * GDB now has support for multi-byte and wide character sets on the
3591 target. Strings whose character type is wchar_t, char16_t, or
3592 char32_t are now correctly printed. GDB supports wide- and unicode-
3593 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3594 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3595 `printf'. This feature requires iconv to work properly; if your
3596 system does not have a working iconv, GDB can use GNU libiconv. See
3597 the installation instructions for more information.
3599 * GDB now supports automatic retrieval of shared library files from
3600 remote targets. To use this feature, specify a system root that begins
3601 with the `remote:' prefix, either via the `set sysroot' command or via
3602 the `--with-sysroot' configure-time option.
3604 * "info sharedlibrary" now takes an optional regex of libraries to show,
3605 and it now reports if a shared library has no debugging information.
3607 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3608 now complete on file names.
3610 * When completing in expressions, gdb will attempt to limit
3611 completions to allowable structure or union fields, where appropriate.
3612 For instance, consider:
3614 # struct example { int f1; double f2; };
3615 # struct example variable;
3618 If the user types TAB at the end of this command line, the available
3619 completions will be "f1" and "f2".
3621 * Inlined functions are now supported. They show up in backtraces, and
3622 the "step", "next", and "finish" commands handle them automatically.
3624 * GDB now supports the token-splicing (##) and stringification (#)
3625 operators when expanding macros. It also supports variable-arity
3628 * GDB now supports inspecting extra signal information, exported by
3629 the new $_siginfo convenience variable. The feature is currently
3630 implemented on linux ARM, i386 and amd64.
3632 * GDB can now display the VFP floating point registers and NEON vector
3633 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3634 can provide these registers (requires Linux 2.6.30 or later). Remote
3635 and simulator targets may also provide them.
3637 * New remote packets
3640 Search memory for a sequence of bytes.
3643 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3644 operation over reliable transport links. Use of this packet is
3645 controlled by the `set remote noack-packet' command.
3648 Kill the process with the specified process ID. Use this in preference
3649 to `k' when multiprocess protocol extensions are supported.
3652 Obtains additional operating system information
3656 Read or write additional signal information.
3658 * Removed remote protocol undocumented extension
3660 An undocumented extension to the remote protocol's `S' stop reply
3661 packet that permited the stub to pass a process id was removed.
3662 Remote servers should use the `T' stop reply packet instead.
3664 * GDB now supports multiple function calling conventions according to the
3665 DWARF-2 DW_AT_calling_convention function attribute.
3667 * The SH target utilizes the aforementioned change to distinguish between gcc
3668 and Renesas calling convention. It also adds the new CLI commands
3669 `set/show sh calling-convention'.
3671 * GDB can now read compressed debug sections, as produced by GNU gold
3672 with the --compress-debug-sections=zlib flag.
3674 * 64-bit core files are now supported on AIX.
3676 * Thread switching is now supported on Tru64.
3678 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3679 which will be allocated using malloc later in program execution.
3681 * The qXfer:libraries:read remote procotol packet now allows passing a
3682 list of section offsets.
3684 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3685 conditions handling signals delivered during attach or thread creation
3686 have also been fixed.
3688 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3689 From the user's standpoint, all unqualified instances of True and False
3690 are treated as the standard definitions, regardless of context.
3692 * GDB now parses C++ symbol and type names more flexibly. For
3695 template<typename T> class C { };
3698 GDB will now correctly handle all of:
3700 ptype C<char const *>
3701 ptype C<char const*>
3702 ptype C<const char *>
3703 ptype C<const char*>
3705 * New features in the GDB remote stub, gdbserver
3707 - The "--wrapper" command-line argument tells gdbserver to use a
3708 wrapper program to launch programs for debugging.
3710 - On PowerPC and S/390 targets, it is now possible to use a single
3711 gdbserver executable to debug both 32-bit and 64-bit programs.
3712 (This requires gdbserver itself to be built as a 64-bit executable.)
3714 - gdbserver uses the new noack protocol mode for TCP connections to
3715 reduce communications latency, if also supported and enabled in GDB.
3717 - Support for the sparc64-linux-gnu target is now included in
3720 - The amd64-linux build of gdbserver now supports debugging both
3721 32-bit and 64-bit programs.
3723 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3724 now support hardware watchpoints, and will use them automatically
3729 GDB now has support for scripting using Python. Whether this is
3730 available is determined at configure time.
3732 New GDB commands can now be written in Python.
3734 * Ada tasking support
3736 Ada tasks can now be inspected in GDB. The following commands have
3740 Print the list of Ada tasks.
3742 Print detailed information about task number N.
3744 Print the task number of the current task.
3746 Switch the context of debugging to task number N.
3748 * Support for user-defined prefixed commands. The "define" command can
3749 add new commands to existing prefixes, e.g. "target".
3751 * Multi-inferior, multi-process debugging.
3753 GDB now has generalized support for multi-inferior debugging. See
3754 "Debugging Multiple Inferiors" in the manual for more information.
3755 Although availability still depends on target support, the command
3756 set is more uniform now. The GNU/Linux specific multi-forks support
3757 has been migrated to this new framework. This implied some user
3758 visible changes; see "New commands" and also "Removed commands"
3761 * Target descriptions can now describe the target OS ABI. See the
3762 "Target Description Format" section in the user manual for more
3765 * Target descriptions can now describe "compatible" architectures
3766 to indicate that the target can execute applications for a different
3767 architecture in addition to those for the main target architecture.
3768 See the "Target Description Format" section in the user manual for
3771 * Multi-architecture debugging.
3773 GDB now includes general supports for debugging applications on
3774 hybrid systems that use more than one single processor architecture
3775 at the same time. Each such hybrid architecture still requires
3776 specific support to be added. The only hybrid architecture supported
3777 in this version of GDB is the Cell Broadband Engine.
3779 * GDB now supports integrated debugging of Cell/B.E. applications that
3780 use both the PPU and SPU architectures. To enable support for hybrid
3781 Cell/B.E. debugging, you need to configure GDB to support both the
3782 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3783 --enable-targets configure option.
3785 * Non-stop mode debugging.
3787 For some targets, GDB now supports an optional mode of operation in
3788 which you can examine stopped threads while other threads continue
3789 to execute freely. This is referred to as non-stop mode, with the
3790 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3791 section in the user manual for more information.
3793 To be able to support remote non-stop debugging, a remote stub needs
3794 to implement the non-stop mode remote protocol extensions, as
3795 described in the "Remote Non-Stop" section of the user manual. The
3796 GDB remote stub, gdbserver, has been adjusted to support these
3797 extensions on linux targets.
3799 * New commands (for set/show, see "New options" below)
3801 catch syscall [NAME(S) | NUMBER(S)]
3802 Catch system calls. Arguments, which should be names of system
3803 calls or their numbers, mean catch only those syscalls. Without
3804 arguments, every syscall will be caught. When the inferior issues
3805 any of the specified syscalls, GDB will stop and announce the system
3806 call, both when it is called and when its call returns. This
3807 feature is currently available with a native GDB running on the
3808 Linux Kernel, under the following architectures: x86, x86_64,
3809 PowerPC and PowerPC64.
3811 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3813 Search memory for a sequence of bytes.
3815 maint set python print-stack
3816 maint show python print-stack
3817 Show a stack trace when an error is encountered in a Python script.
3820 Invoke CODE by passing it to the Python interpreter.
3825 These allow macros to be defined, undefined, and listed
3829 Show operating system information about processes.
3832 List the inferiors currently under GDB's control.
3835 Switch focus to inferior number NUM.
3838 Detach from inferior number NUM.
3841 Kill inferior number NUM.
3845 set spu stop-on-load
3846 show spu stop-on-load
3847 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3849 set spu auto-flush-cache
3850 show spu auto-flush-cache
3851 Control whether to automatically flush the software-managed cache
3852 during Cell/B.E. debugging.
3854 set sh calling-convention
3855 show sh calling-convention
3856 Control the calling convention used when calling SH target functions.
3859 show debug timestamp
3860 Control display of timestamps with GDB debugging output.
3862 set disassemble-next-line
3863 show disassemble-next-line
3864 Control display of disassembled source lines or instructions when
3867 set remote noack-packet
3868 show remote noack-packet
3869 Set/show the use of remote protocol QStartNoAckMode packet. See above
3870 under "New remote packets."
3872 set remote query-attached-packet
3873 show remote query-attached-packet
3874 Control use of remote protocol `qAttached' (query-attached) packet.
3876 set remote read-siginfo-object
3877 show remote read-siginfo-object
3878 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3881 set remote write-siginfo-object
3882 show remote write-siginfo-object
3883 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3886 set remote reverse-continue
3887 show remote reverse-continue
3888 Control use of remote protocol 'bc' (reverse-continue) packet.
3890 set remote reverse-step
3891 show remote reverse-step
3892 Control use of remote protocol 'bs' (reverse-step) packet.
3894 set displaced-stepping
3895 show displaced-stepping
3896 Control displaced stepping mode. Displaced stepping is a way to
3897 single-step over breakpoints without removing them from the debuggee.
3898 Also known as "out-of-line single-stepping".
3901 show debug displaced
3902 Control display of debugging info for displaced stepping.
3904 maint set internal-error
3905 maint show internal-error
3906 Control what GDB does when an internal error is detected.
3908 maint set internal-warning
3909 maint show internal-warning
3910 Control what GDB does when an internal warning is detected.
3915 Use a wrapper program to launch programs for debugging.
3917 set multiple-symbols (all|ask|cancel)
3918 show multiple-symbols
3919 The value of this variable can be changed to adjust the debugger behavior
3920 when an expression or a breakpoint location contains an ambiguous symbol
3921 name (an overloaded function name, for instance).
3923 set breakpoint always-inserted
3924 show breakpoint always-inserted
3925 Keep breakpoints always inserted in the target, as opposed to inserting
3926 them when resuming the target, and removing them when the target stops.
3927 This option can improve debugger performance on slow remote targets.
3929 set arm fallback-mode (arm|thumb|auto)
3930 show arm fallback-mode
3931 set arm force-mode (arm|thumb|auto)
3933 These commands control how ARM GDB determines whether instructions
3934 are ARM or Thumb. The default for both settings is auto, which uses
3935 the current CPSR value for instructions without symbols; previous
3936 versions of GDB behaved as if "set arm fallback-mode arm".
3938 set disable-randomization
3939 show disable-randomization
3940 Standalone programs run with the virtual address space randomization enabled
3941 by default on some platforms. This option keeps the addresses stable across
3942 multiple debugging sessions.
3946 Control whether other threads are stopped or not when some thread hits
3951 Requests that asynchronous execution is enabled in the target, if available.
3952 In this case, it's possible to resume target in the background, and interact
3953 with GDB while the target is running. "show target-async" displays the
3954 current state of asynchronous execution of the target.
3956 set target-wide-charset
3957 show target-wide-charset
3958 The target-wide-charset is the name of the character set that GDB
3959 uses when printing characters whose type is wchar_t.
3961 set tcp auto-retry (on|off)
3963 set tcp connect-timeout
3964 show tcp connect-timeout
3965 These commands allow GDB to retry failed TCP connections to a remote stub
3966 with a specified timeout period; this is useful if the stub is launched
3967 in parallel with GDB but may not be ready to accept connections immediately.
3969 set libthread-db-search-path
3970 show libthread-db-search-path
3971 Control list of directories which GDB will search for appropriate
3974 set schedule-multiple (on|off)
3975 show schedule-multiple
3976 Allow GDB to resume all threads of all processes or only threads of
3977 the current process.
3981 Use more aggressive caching for accesses to the stack. This improves
3982 performance of remote debugging (particularly backtraces) without
3983 affecting correctness.
3985 set interactive-mode (on|off|auto)
3986 show interactive-mode
3987 Control whether GDB runs in interactive mode (on) or not (off).
3988 When in interactive mode, GDB waits for the user to answer all
3989 queries. Otherwise, GDB does not wait and assumes the default
3990 answer. When set to auto (the default), GDB determines which
3991 mode to use based on the stdin settings.
3996 For program forks, this is replaced by the new more generic `info
3997 inferiors' command. To list checkpoints, you can still use the
3998 `info checkpoints' command, which was an alias for the `info forks'
4002 Replaced by the new `inferior' command. To switch between
4003 checkpoints, you can still use the `restart' command, which was an
4004 alias for the `fork' command.
4007 This is removed, since some targets don't have a notion of
4008 processes. To switch between processes, you can still use the
4009 `inferior' command using GDB's own inferior number.
4012 For program forks, this is replaced by the new more generic `kill
4013 inferior' command. To delete a checkpoint, you can still use the
4014 `delete checkpoint' command, which was an alias for the `delete
4018 For program forks, this is replaced by the new more generic `detach
4019 inferior' command. To detach a checkpoint, you can still use the
4020 `detach checkpoint' command, which was an alias for the `detach
4023 * New native configurations
4025 x86/x86_64 Darwin i[34567]86-*-darwin*
4027 x86_64 MinGW x86_64-*-mingw*
4031 Lattice Mico32 lm32-*
4032 x86 DICOS i[34567]86-*-dicos*
4033 x86_64 DICOS x86_64-*-dicos*
4036 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4037 (mingw32ce) debugging.
4043 These commands were actually not implemented on any target.
4045 *** Changes in GDB 6.8
4047 * New native configurations
4049 NetBSD/hppa hppa*-*netbsd*
4050 Xtensa GNU/Linux xtensa*-*-linux*
4054 NetBSD/hppa hppa*-*-netbsd*
4055 Xtensa GNU/Lunux xtensa*-*-linux*
4057 * Change in command line behavior -- corefiles vs. process ids.
4059 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4060 attaching to process NUMBER fails, GDB no longer attempts to open a
4061 core file named NUMBER. Attaching to a program using the -c option
4062 is no longer supported. Instead, use the '-p' or '--pid' options.
4064 * GDB can now be built as a native debugger for debugging Windows x86
4065 (mingw32) Portable Executable (PE) programs.
4067 * Pending breakpoints no longer change their number when their address
4070 * GDB now supports breakpoints with multiple locations,
4071 including breakpoints on C++ constructors, inside C++ templates,
4072 and in inlined functions.
4074 * GDB's ability to debug optimized code has been improved. GDB more
4075 accurately identifies function bodies and lexical blocks that occupy
4076 more than one contiguous range of addresses.
4078 * Target descriptions can now describe registers for PowerPC.
4080 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4081 registers on PowerPC targets.
4083 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4084 targets even when the libthread_db library is not available.
4086 * The GDB remote stub, gdbserver, now supports the new file transfer
4087 commands (remote put, remote get, and remote delete).
4089 * The GDB remote stub, gdbserver, now supports run and attach in
4090 extended-remote mode.
4092 * hppa*64*-*-hpux11* target broken
4093 The debugger is unable to start a program and fails with the following
4094 error: "Error trying to get information about dynamic linker".
4095 The gdb-6.7 release is also affected.
4097 * GDB now supports the --enable-targets= configure option to allow
4098 building a single GDB executable that supports multiple remote
4099 target architectures.
4101 * GDB now supports debugging C and C++ programs which use the
4102 Decimal Floating Point extension. In addition, the PowerPC target
4103 now has a set of pseudo-registers to inspect decimal float values
4104 stored in two consecutive float registers.
4106 * The -break-insert MI command can optionally create pending
4109 * Improved support for debugging Ada
4110 Many improvements to the Ada language support have been made. These
4112 - Better support for Ada2005 interface types
4113 - Improved handling of arrays and slices in general
4114 - Better support for Taft-amendment types
4115 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4117 - Improved command completion in Ada
4120 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4125 set print frame-arguments (all|scalars|none)
4126 show print frame-arguments
4127 The value of this variable can be changed to control which argument
4128 values should be printed by the debugger when displaying a frame.
4133 Transfer files to and from a remote target, and delete remote files.
4140 Transfer files to and from a remote target, and delete remote files.
4142 * New remote packets
4149 Open, close, read, write, and delete files on the remote system.
4152 Attach to an existing process on the remote system, in extended-remote
4156 Run a new process on the remote system, in extended-remote mode.
4158 *** Changes in GDB 6.7
4160 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4161 bfd, libiberty and opcodes, as revealed by static analysis donated by
4162 Coverity, Inc. (http://scan.coverity.com).
4164 * When looking up multiply-defined global symbols, GDB will now prefer the
4165 symbol definition in the current shared library if it was built using the
4166 -Bsymbolic linker option.
4168 * When the Text User Interface (TUI) is not configured, GDB will now
4169 recognize the -tui command-line option and print a message that the TUI
4172 * The GDB remote stub, gdbserver, now has lower overhead for high
4173 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4175 * GDB for MIPS targets now autodetects whether a remote target provides
4176 32-bit or 64-bit register values.
4178 * Support for C++ member pointers has been improved.
4180 * GDB now understands XML target descriptions, which specify the
4181 target's overall architecture. GDB can read a description from
4182 a local file or over the remote serial protocol.
4184 * Vectors of single-byte data use a new integer type which is not
4185 automatically displayed as character or string data.
4187 * The /s format now works with the print command. It displays
4188 arrays of single-byte integers and pointers to single-byte integers
4191 * Target descriptions can now describe target-specific registers,
4192 for architectures which have implemented the support (currently
4193 only ARM, M68K, and MIPS).
4195 * GDB and the GDB remote stub, gdbserver, now support the XScale
4198 * The GDB remote stub, gdbserver, has been updated to support
4199 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4200 has been rewritten to use the standard GDB remote protocol.
4202 * GDB can now step into C++ functions which are called through thunks.
4204 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4206 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4207 layout. It also supports a TextSeg= and DataSeg= response when only
4208 segment base addresses (rather than offsets) are available.
4210 * The /i format now outputs any trailing branch delay slot instructions
4211 immediately following the last instruction within the count specified.
4213 * The GDB remote protocol "T" stop reply packet now supports a
4214 "library" response. Combined with the new "qXfer:libraries:read"
4215 packet, this response allows GDB to debug shared libraries on targets
4216 where the operating system manages the list of loaded libraries (e.g.
4217 Windows and SymbianOS).
4219 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4220 (DLLs) on Windows and Windows CE targets.
4222 * GDB now supports a faster verification that a .debug file matches its binary
4223 according to its build-id signature, if the signature is present.
4229 Enable or disable hardware flow control (RTS/CTS) on the serial port
4230 when debugging using remote targets.
4232 set mem inaccessible-by-default
4233 show mem inaccessible-by-default
4234 If the target supplies a memory map, for instance via the remote
4235 protocol's "qXfer:memory-map:read" packet, setting this variable
4236 prevents GDB from accessing memory outside the memory map. This
4237 is useful for targets with memory mapped registers or which react
4238 badly to accesses of unmapped address space.
4240 set breakpoint auto-hw
4241 show breakpoint auto-hw
4242 If the target supplies a memory map, for instance via the remote
4243 protocol's "qXfer:memory-map:read" packet, setting this variable
4244 lets GDB use hardware breakpoints automatically for memory regions
4245 where it can not use software breakpoints. This covers both the
4246 "break" command and internal breakpoints used for other commands
4247 including "next" and "finish".
4250 catch exception unhandled
4251 Stop the program execution when Ada exceptions are raised.
4254 Stop the program execution when an Ada assertion failed.
4258 Set an alternate system root for target files. This is a more
4259 general version of "set solib-absolute-prefix", which is now
4260 an alias to "set sysroot".
4263 Provide extended SPU facility status information. This set of
4264 commands is available only when debugging the Cell/B.E. SPU
4267 * New native configurations
4269 OpenBSD/sh sh*-*openbsd*
4272 unset tdesc filename
4274 Use the specified local file as an XML target description, and do
4275 not query the target for its built-in description.
4279 OpenBSD/sh sh*-*-openbsd*
4280 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4281 Toshiba Media Processor mep-elf
4283 * New remote packets
4286 Ignore the specified signals; pass them directly to the debugged program
4287 without stopping other threads or reporting them to GDB.
4289 qXfer:features:read:
4290 Read an XML target description from the target, which describes its
4295 Read or write contents of an spufs file on the target system. These
4296 packets are available only on the Cell/B.E. SPU architecture.
4298 qXfer:libraries:read:
4299 Report the loaded shared libraries. Combined with new "T" packet
4300 response, this packet allows GDB to debug shared libraries on
4301 targets where the operating system manages the list of loaded
4302 libraries (e.g. Windows and SymbianOS).
4306 Support for these obsolete configurations has been removed.
4314 i[34567]86-*-lynxos*
4315 i[34567]86-*-netware*
4316 i[34567]86-*-sco3.2v5*
4317 i[34567]86-*-sco3.2v4*
4319 i[34567]86-*-sysv4.2*
4322 i[34567]86-*-unixware2*
4323 i[34567]86-*-unixware*
4332 * Other removed features
4339 Various m68k-only ROM monitors.
4346 Various Renesas ROM monitors and debugging interfaces for SH and
4351 Support for a Macraigor serial interface to on-chip debugging.
4352 GDB does not directly support the newer parallel or USB
4357 A debug information format. The predecessor to DWARF 2 and
4358 DWARF 3, which are still supported.
4360 Support for the HP aCC compiler on HP-UX/PA-RISC
4362 SOM-encapsulated symbolic debugging information, automatic
4363 invocation of pxdb, and the aCC custom C++ ABI. This does not
4364 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4365 with aCC can still be debugged on an assembly level.
4367 MIPS ".pdr" sections
4369 A MIPS-specific format used to describe stack frame layout
4370 in debugging information.
4374 GDB could work with an older version of Guile to debug
4375 the interpreter and Scheme programs running in it.
4377 set mips stack-arg-size
4378 set mips saved-gpreg-size
4380 Use "set mips abi" to control parameter passing for MIPS.
4382 *** Changes in GDB 6.6
4387 Cell Broadband Engine SPU spu-elf
4389 * GDB can now be configured as a cross-debugger targeting native Windows
4390 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4391 running on a Windows system over TCP/IP to debug Windows programs.
4393 * The GDB remote stub, gdbserver, has been updated to support Windows and
4394 Cygwin debugging. Both single-threaded and multi-threaded programs are
4397 * The "set trust-readonly-sections" command works again. This command was
4398 broken in GDB 6.3, 6.4, and 6.5.
4400 * The "load" command now supports writing to flash memory, if the remote
4401 stub provides the required support.
4403 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4404 longer requires symbolic debug information (e.g. DWARF-2).
4409 unset substitute-path
4410 show substitute-path
4411 Manage a list of substitution rules that GDB uses to rewrite the name
4412 of the directories where the sources are located. This can be useful
4413 for instance when the sources were moved to a different location
4414 between compilation and debugging.
4418 Print each CLI command as it is executed. Each command is prefixed with
4419 a number of `+' symbols representing the nesting depth.
4420 The source command now has a `-v' option to enable the same feature.
4424 The ARM Demon monitor support (RDP protocol, "target rdp").
4426 Kernel Object Display, an embedded debugging feature which only worked with
4427 an obsolete version of Cisco IOS.
4429 The 'set download-write-size' and 'show download-write-size' commands.
4431 * New remote packets
4434 Tell a stub about GDB client features, and request remote target features.
4435 The first feature implemented is PacketSize, which allows the target to
4436 specify the size of packets it can handle - to minimize the number of
4437 packets required and improve performance when connected to a remote
4441 Fetch an OS auxilliary vector from the remote stub. This packet is a
4442 more efficient replacement for qPart:auxv:read.
4444 qXfer:memory-map:read:
4445 Fetch a memory map from the remote stub, including information about
4446 RAM, ROM, and flash memory devices.
4451 Erase and program a flash memory device.
4453 * Removed remote packets
4456 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4457 used it, and only gdbserver implemented it.
4459 *** Changes in GDB 6.5
4463 Renesas M32C/M16C m32c-elf
4465 Morpho Technologies ms1 ms1-elf
4469 init-if-undefined Initialize a convenience variable, but
4470 only if it doesn't already have a value.
4472 The following commands are presently only implemented for native GNU/Linux:
4474 checkpoint Save a snapshot of the program state.
4476 restart <n> Return the program state to a
4477 previously saved state.
4479 info checkpoints List currently saved checkpoints.
4481 delete-checkpoint <n> Delete a previously saved checkpoint.
4483 set|show detach-on-fork Tell gdb whether to detach from a newly
4484 forked process, or to keep debugging it.
4486 info forks List forks of the user program that
4487 are available to be debugged.
4489 fork <n> Switch to debugging one of several
4490 forks of the user program that are
4491 available to be debugged.
4493 delete-fork <n> Delete a fork from the list of forks
4494 that are available to be debugged (and
4495 kill the forked process).
4497 detach-fork <n> Delete a fork from the list of forks
4498 that are available to be debugged (and
4499 allow the process to continue).
4503 Morpho Technologies ms2 ms1-elf
4505 * Improved Windows host support
4507 GDB now builds as a cross debugger hosted on i686-mingw32, including
4508 native console support, and remote communications using either
4509 network sockets or serial ports.
4511 * Improved Modula-2 language support
4513 GDB can now print most types in the Modula-2 syntax. This includes:
4514 basic types, set types, record types, enumerated types, range types,
4515 pointer types and ARRAY types. Procedure var parameters are correctly
4516 printed and hexadecimal addresses and character constants are also
4517 written in the Modula-2 syntax. Best results can be obtained by using
4518 GNU Modula-2 together with the -gdwarf-2 command line option.
4522 The ARM rdi-share module.
4524 The Netware NLM debug server.
4526 *** Changes in GDB 6.4
4528 * New native configurations
4530 OpenBSD/arm arm*-*-openbsd*
4531 OpenBSD/mips64 mips64-*-openbsd*
4535 Morpho Technologies ms1 ms1-elf
4537 * New command line options
4539 --batch-silent As for --batch, but totally silent.
4540 --return-child-result The debugger will exist with the same value
4541 the child (debugged) program exited with.
4542 --eval-command COMMAND, -ex COMMAND
4543 Execute a single GDB CLI command. This may be
4544 specified multiple times and in conjunction
4545 with the --command (-x) option.
4547 * Deprecated commands removed
4549 The following commands, that were deprecated in 2000, have been
4553 set|show arm disassembly-flavor set|show arm disassembler
4554 othernames set arm disassembler
4555 set|show remotedebug set|show debug remote
4556 set|show archdebug set|show debug arch
4557 set|show eventdebug set|show debug event
4560 * New BSD user-level threads support
4562 It is now possible to debug programs using the user-level threads
4563 library on OpenBSD and FreeBSD. Currently supported (target)
4566 FreeBSD/amd64 x86_64-*-freebsd*
4567 FreeBSD/i386 i386-*-freebsd*
4568 OpenBSD/i386 i386-*-openbsd*
4570 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4571 are not yet supported.
4573 * New support for Matsushita MN10300 w/sim added
4574 (Work in progress). mn10300-elf.
4576 * REMOVED configurations and files
4578 VxWorks and the XDR protocol *-*-vxworks
4579 Motorola MCORE mcore-*-*
4580 National Semiconductor NS32000 ns32k-*-*
4582 * New "set print array-indexes" command
4584 After turning this setting "on", GDB prints the index of each element
4585 when displaying arrays. The default is "off" to preserve the previous
4588 * VAX floating point support
4590 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4592 * User-defined command support
4594 In addition to using $arg0..$arg9 for argument passing, it is now possible
4595 to use $argc to determine now many arguments have been passed. See the
4596 section on user-defined commands in the user manual for more information.
4598 *** Changes in GDB 6.3:
4600 * New command line option
4602 GDB now accepts -l followed by a number to set the timeout for remote
4605 * GDB works with GCC -feliminate-dwarf2-dups
4607 GDB now supports a more compact representation of DWARF-2 debug
4608 information using DW_FORM_ref_addr references. These are produced
4609 by GCC with the option -feliminate-dwarf2-dups and also by some
4610 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4611 to use -feliminate-dwarf2-dups.
4613 * Internationalization
4615 When supported by the host system, GDB will be built with
4616 internationalization (libintl). The task of marking up the sources is
4617 continued, we're looking forward to our first translation.
4621 Initial support for debugging programs compiled with the GNAT
4622 implementation of the Ada programming language has been integrated
4623 into GDB. In this release, support is limited to expression evaluation.
4625 * New native configurations
4627 GNU/Linux/m32r m32r-*-linux-gnu
4631 GDB's remote protocol now includes support for the 'p' packet. This
4632 packet is used to fetch individual registers from a remote inferior.
4634 * END-OF-LIFE registers[] compatibility module
4636 GDB's internal register infrastructure has been completely rewritten.
4637 The new infrastructure making possible the implementation of key new
4638 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4641 GDB 6.3 will be the last release to include the the registers[]
4642 compatibility module that allowed out-of-date configurations to
4643 continue to work. This change directly impacts the following
4653 powerpc bdm protocol
4655 Unless there is activity to revive these configurations, they will be
4656 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4658 * OBSOLETE configurations and files
4660 Configurations that have been declared obsolete in this release have
4661 been commented out. Unless there is activity to revive these
4662 configurations, the next release of GDB will have their sources
4663 permanently REMOVED.
4672 *** Changes in GDB 6.2.1:
4674 * MIPS `break main; run' gave an heuristic-fence-post warning
4676 When attempting to run even a simple program, a warning about
4677 heuristic-fence-post being hit would be reported. This problem has
4680 * MIPS IRIX 'long double' crashed GDB
4682 When examining a long double variable, GDB would get a segmentation
4683 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4684 IRIX long double values).
4688 A bug in the VAX stack code was causing problems with the "next"
4689 command. This problem has been fixed.
4691 *** Changes in GDB 6.2:
4693 * Fix for ``many threads''
4695 On GNU/Linux systems that use the NPTL threads library, a program
4696 rapidly creating and deleting threads would confuse GDB leading to the
4699 ptrace: No such process.
4700 thread_db_get_info: cannot get thread info: generic error
4702 This problem has been fixed.
4704 * "-async" and "-noasync" options removed.
4706 Support for the broken "-noasync" option has been removed (it caused
4709 * New ``start'' command.
4711 This command runs the program until the begining of the main procedure.
4713 * New BSD Kernel Data Access Library (libkvm) interface
4715 Using ``target kvm'' it is now possible to debug kernel core dumps and
4716 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4717 platforms. Currently supported (native-only) configurations are:
4719 FreeBSD/amd64 x86_64-*-freebsd*
4720 FreeBSD/i386 i?86-*-freebsd*
4721 NetBSD/i386 i?86-*-netbsd*
4722 NetBSD/m68k m68*-*-netbsd*
4723 NetBSD/sparc sparc-*-netbsd*
4724 OpenBSD/amd64 x86_64-*-openbsd*
4725 OpenBSD/i386 i?86-*-openbsd*
4726 OpenBSD/m68k m68*-openbsd*
4727 OpenBSD/sparc sparc-*-openbsd*
4729 * Signal trampoline code overhauled
4731 Many generic problems with GDB's signal handling code have been fixed.
4732 These include: backtraces through non-contiguous stacks; recognition
4733 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4734 call; backtrace through a signal trampoline; step into and out of
4735 signal handlers; and single-stepping in the signal trampoline.
4737 Please note that kernel bugs are a limiting factor here. These
4738 features have been shown to work on an s390 GNU/Linux system that
4739 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4741 * Cygwin support for DWARF 2 added.
4743 * New native configurations
4745 GNU/Linux/hppa hppa*-*-linux*
4746 OpenBSD/hppa hppa*-*-openbsd*
4747 OpenBSD/m68k m68*-*-openbsd*
4748 OpenBSD/m88k m88*-*-openbsd*
4749 OpenBSD/powerpc powerpc-*-openbsd*
4750 NetBSD/vax vax-*-netbsd*
4751 OpenBSD/vax vax-*-openbsd*
4753 * END-OF-LIFE frame compatibility module
4755 GDB's internal frame infrastructure has been completely rewritten.
4756 The new infrastructure making it possible to support key new features
4757 including DWARF 2 Call Frame Information. To aid in the task of
4758 migrating old configurations to this new infrastructure, a
4759 compatibility module, that allowed old configurations to continue to
4760 work, was also included.
4762 GDB 6.2 will be the last release to include this frame compatibility
4763 module. This change directly impacts the following configurations:
4773 Unless there is activity to revive these configurations, they will be
4774 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4776 * REMOVED configurations and files
4778 Sun 3, running SunOS 3 m68*-*-sunos3*
4779 Sun 3, running SunOS 4 m68*-*-sunos4*
4780 Sun 2, running SunOS 3 m68000-*-sunos3*
4781 Sun 2, running SunOS 4 m68000-*-sunos4*
4782 Motorola 680x0 running LynxOS m68*-*-lynxos*
4783 AT&T 3b1/Unix pc m68*-att-*
4784 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4785 decstation mips-dec-* mips-little-*
4786 riscos mips-*-riscos* mips-*-sysv*
4787 sonymips mips-sony-*
4788 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4790 *** Changes in GDB 6.1.1:
4792 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4794 The TUI (Text-mode User Interface) is now built as part of a default
4795 GDB configuration. It is enabled by either selecting the TUI with the
4796 command line option "-i=tui" or by running the separate "gdbtui"
4797 program. For more information on the TUI, see the manual "Debugging
4800 * Pending breakpoint support (also included in GDB 6.1)
4802 Support has been added to allow you to specify breakpoints in shared
4803 libraries that have not yet been loaded. If a breakpoint location
4804 cannot be found, and the "breakpoint pending" option is set to auto,
4805 GDB queries you if you wish to make the breakpoint pending on a future
4806 shared-library load. If and when GDB resolves the breakpoint symbol,
4807 the pending breakpoint is removed as one or more regular breakpoints
4810 Pending breakpoints are very useful for GCJ Java debugging.
4812 * Fixed ISO-C build problems
4814 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4815 non ISO-C code that stopped them being built using a more strict ISO-C
4816 compiler (e.g., IBM's C compiler).
4818 * Fixed build problem on IRIX 5
4820 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4821 wasn't able to compile compile on an IRIX 5 system.
4823 * Added execute permission to gdb/gdbserver/configure
4825 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4826 permission. This bug would cause configure to fail on a number of
4827 systems (Solaris, IRIX). Ref: server/519.
4829 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4831 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4832 has been updated to use constant array sizes.
4834 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4836 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4837 its generated DWARF Call Frame Info. This encoding was causing GDB to
4838 panic, that panic has been fixed. Ref: gdb/1628.
4840 * Fixed a problem when examining parameters in shared library code.
4842 When examining parameters in optimized shared library code generated
4843 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4844 not available''. GDB now correctly displays the variable's value.
4846 *** Changes in GDB 6.1:
4848 * Removed --with-mmalloc
4850 Support for the mmalloc memory manager has been removed, as it
4851 conflicted with the internal gdb byte cache.
4853 * Changes in AMD64 configurations
4855 The AMD64 target now includes the %cs and %ss registers. As a result
4856 the AMD64 remote protocol has changed; this affects the floating-point
4857 and SSE registers. If you rely on those registers for your debugging,
4858 you should upgrade gdbserver on the remote side.
4860 * Revised SPARC target
4862 The SPARC target has been completely revised, incorporating the
4863 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4864 support for LynxOS and SunOS 4 has been dropped. Calling functions
4865 from within GDB on operating systems with a non-executable stack
4866 (Solaris, OpenBSD) now works.
4870 GDB has a new C++ demangler which does a better job on the mangled
4871 names generated by current versions of g++. It also runs faster, so
4872 with this and other changes gdb should now start faster on large C++
4875 * DWARF 2 Location Expressions
4877 GDB support for location expressions has been extended to support function
4878 arguments and frame bases. Older versions of GDB could crash when they
4881 * C++ nested types and namespaces
4883 GDB's support for nested types and namespaces in C++ has been
4884 improved, especially if you use the DWARF 2 debugging format. (This
4885 is the default for recent versions of GCC on most platforms.)
4886 Specifically, if you have a class "Inner" defined within a class or
4887 namespace "Outer", then GDB realizes that the class's name is
4888 "Outer::Inner", not simply "Inner". This should greatly reduce the
4889 frequency of complaints about not finding RTTI symbols. In addition,
4890 if you are stopped at inside of a function defined within a namespace,
4891 GDB modifies its name lookup accordingly.
4893 * New native configurations
4895 NetBSD/amd64 x86_64-*-netbsd*
4896 OpenBSD/amd64 x86_64-*-openbsd*
4897 OpenBSD/alpha alpha*-*-openbsd*
4898 OpenBSD/sparc sparc-*-openbsd*
4899 OpenBSD/sparc64 sparc64-*-openbsd*
4901 * New debugging protocols
4903 M32R with SDI protocol m32r-*-elf*
4905 * "set prompt-escape-char" command deleted.
4907 The command "set prompt-escape-char" has been deleted. This command,
4908 and its very obscure effet on GDB's prompt, was never documented,
4909 tested, nor mentioned in the NEWS file.
4911 * OBSOLETE configurations and files
4913 Configurations that have been declared obsolete in this release have
4914 been commented out. Unless there is activity to revive these
4915 configurations, the next release of GDB will have their sources
4916 permanently REMOVED.
4918 Sun 3, running SunOS 3 m68*-*-sunos3*
4919 Sun 3, running SunOS 4 m68*-*-sunos4*
4920 Sun 2, running SunOS 3 m68000-*-sunos3*
4921 Sun 2, running SunOS 4 m68000-*-sunos4*
4922 Motorola 680x0 running LynxOS m68*-*-lynxos*
4923 AT&T 3b1/Unix pc m68*-att-*
4924 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4925 decstation mips-dec-* mips-little-*
4926 riscos mips-*-riscos* mips-*-sysv*
4927 sonymips mips-sony-*
4928 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4930 * REMOVED configurations and files
4932 SGI Irix-4.x mips-sgi-irix4 or iris4
4933 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4934 Z8000 simulator z8k-zilog-none or z8ksim
4935 Matsushita MN10200 w/simulator mn10200-*-*
4936 H8/500 simulator h8500-hitachi-hms or h8500hms
4937 HP/PA running BSD hppa*-*-bsd*
4938 HP/PA running OSF/1 hppa*-*-osf*
4939 HP/PA Pro target hppa*-*-pro*
4940 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4941 386BSD i[3456]86-*-bsd*
4942 Sequent family i[3456]86-sequent-sysv4*
4943 i[3456]86-sequent-sysv*
4944 i[3456]86-sequent-bsd*
4945 SPARC running LynxOS sparc-*-lynxos*
4946 SPARC running SunOS 4 sparc-*-sunos4*
4947 Tsqware Sparclet sparclet-*-*
4948 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4950 *** Changes in GDB 6.0:
4954 Support for debugging the Objective-C programming language has been
4955 integrated into GDB.
4957 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4959 DWARF 2's Call Frame Information makes available compiler generated
4960 information that more exactly describes the program's run-time stack.
4961 By using this information, GDB is able to provide more robust stack
4964 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4965 have been updated to use a new backtrace mechanism which includes
4966 DWARF 2 CFI support.
4970 GDB's remote protocol has been extended to include support for hosted
4971 file I/O (where the remote target uses GDB's file system). See GDB's
4972 remote protocol documentation for details.
4974 * All targets using the new architecture framework.
4976 All of GDB's targets have been updated to use the new internal
4977 architecture framework. The way is now open for future GDB releases
4978 to include cross-architecture native debugging support (i386 on amd64,
4981 * GNU/Linux's Thread Local Storage (TLS)
4983 GDB now includes support for for the GNU/Linux implementation of
4984 per-thread variables.
4986 * GNU/Linux's Native POSIX Thread Library (NPTL)
4988 GDB's thread code has been updated to work with either the new
4989 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4991 * Separate debug info.
4993 GDB, in conjunction with BINUTILS, now supports a mechanism for
4994 automatically loading debug information from a separate file. Instead
4995 of shipping full debug and non-debug versions of system libraries,
4996 system integrators can now instead ship just the stripped libraries
4997 and optional debug files.
4999 * DWARF 2 Location Expressions
5001 DWARF 2 Location Expressions allow the compiler to more completely
5002 describe the location of variables (even in optimized code) to the
5005 GDB now includes preliminary support for location expressions (support
5006 for DW_OP_piece is still missing).
5010 A number of long standing bugs that caused GDB to die while starting a
5011 Java application have been fixed. GDB's Java support is now
5012 considered "useable".
5014 * GNU/Linux support for fork, vfork, and exec.
5016 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5017 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5020 * GDB supports logging output to a file
5022 There are two new commands, "set logging" and "show logging", which can be
5023 used to capture GDB's output to a file.
5025 * The meaning of "detach" has changed for gdbserver
5027 The "detach" command will now resume the application, as documented. To
5028 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5031 * d10v, m68hc11 `regs' command deprecated
5033 The `info registers' command has been updated so that it displays the
5034 registers using a format identical to the old `regs' command.
5038 A new command, "maint set profile on/off", has been added. This command can
5039 be used to enable or disable profiling while running GDB, to profile a
5040 session or a set of commands. In addition there is a new configure switch,
5041 "--enable-profiling", which will cause GDB to be compiled with profiling
5042 data, for more informative profiling results.
5044 * Default MI syntax changed to "mi2".
5046 The default MI (machine interface) syntax, enabled by the command line
5047 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5048 "mi1", can be enabled by specifying the option "-i=mi1".
5050 Support for the original "mi0" syntax (included in GDB 5.0) has been
5053 Fix for gdb/192: removed extraneous space when displaying frame level.
5054 Fix for gdb/672: update changelist is now output in mi list format.
5055 Fix for gdb/702: a -var-assign that updates the value now shows up
5056 in a subsequent -var-update.
5058 * New native configurations.
5060 FreeBSD/amd64 x86_64-*-freebsd*
5062 * Multi-arched targets.
5064 HP/PA HPUX11 hppa*-*-hpux*
5065 Renesas M32R/D w/simulator m32r-*-elf*
5067 * OBSOLETE configurations and files
5069 Configurations that have been declared obsolete in this release have
5070 been commented out. Unless there is activity to revive these
5071 configurations, the next release of GDB will have their sources
5072 permanently REMOVED.
5074 Z8000 simulator z8k-zilog-none or z8ksim
5075 Matsushita MN10200 w/simulator mn10200-*-*
5076 H8/500 simulator h8500-hitachi-hms or h8500hms
5077 HP/PA running BSD hppa*-*-bsd*
5078 HP/PA running OSF/1 hppa*-*-osf*
5079 HP/PA Pro target hppa*-*-pro*
5080 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5081 Sequent family i[3456]86-sequent-sysv4*
5082 i[3456]86-sequent-sysv*
5083 i[3456]86-sequent-bsd*
5084 Tsqware Sparclet sparclet-*-*
5085 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5087 * REMOVED configurations and files
5090 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5091 IBM AIX PS/2 i[3456]86-*-aix
5092 i386 running Mach 3.0 i[3456]86-*-mach3*
5093 i386 running Mach i[3456]86-*-mach*
5094 i386 running OSF/1 i[3456]86-*osf1mk*
5095 HP/Apollo 68k Family m68*-apollo*-sysv*,
5097 m68*-hp-bsd*, m68*-hp-hpux*
5098 Argonaut Risc Chip (ARC) arc-*-*
5099 Mitsubishi D30V d30v-*-*
5100 Fujitsu FR30 fr30-*-elf*
5101 OS/9000 i[34]86-*-os9k
5102 I960 with MON960 i960-*-coff
5104 * MIPS $fp behavior changed
5106 The convenience variable $fp, for the MIPS, now consistently returns
5107 the address of the current frame's base. Previously, depending on the
5108 context, $fp could refer to either $sp or the current frame's base
5109 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5110 The GNU Source-Level Debugger''.
5112 *** Changes in GDB 5.3:
5114 * GNU/Linux shared library multi-threaded performance improved.
5116 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5117 `/proc', in preference to `ptrace' for memory reads. This may result
5118 in an improvement in the start-up time of multi-threaded, shared
5119 library applications when run under GDB. One GDB user writes: ``loads
5120 shared libs like mad''.
5122 * ``gdbserver'' now supports multi-threaded applications on some targets
5124 Support for debugging multi-threaded applications which use
5125 the GNU/Linux LinuxThreads package has been added for
5126 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5127 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5129 * GDB now supports C/C++ preprocessor macros.
5131 GDB now expands preprocessor macro invocations in C/C++ expressions,
5132 and provides various commands for showing macro definitions and how
5135 The new command `macro expand EXPRESSION' expands any macro
5136 invocations in expression, and shows the result.
5138 The new command `show macro MACRO-NAME' shows the definition of the
5139 macro named MACRO-NAME, and where it was defined.
5141 Most compilers don't include information about macros in the debugging
5142 information by default. In GCC 3.1, for example, you need to compile
5143 your program with the options `-gdwarf-2 -g3'. If the macro
5144 information is present in the executable, GDB will read it.
5146 * Multi-arched targets.
5148 DEC Alpha (partial) alpha*-*-*
5149 DEC VAX (partial) vax-*-*
5151 National Semiconductor NS32000 (partial) ns32k-*-*
5152 Motorola 68000 (partial) m68k-*-*
5153 Motorola MCORE mcore-*-*
5157 Fujitsu FRV architecture added by Red Hat frv*-*-*
5160 * New native configurations
5162 Alpha NetBSD alpha*-*-netbsd*
5163 SH NetBSD sh*-*-netbsdelf*
5164 MIPS NetBSD mips*-*-netbsd*
5165 UltraSPARC NetBSD sparc64-*-netbsd*
5167 * OBSOLETE configurations and files
5169 Configurations that have been declared obsolete in this release have
5170 been commented out. Unless there is activity to revive these
5171 configurations, the next release of GDB will have their sources
5172 permanently REMOVED.
5174 Mitsubishi D30V d30v-*-*
5175 OS/9000 i[34]86-*-os9k
5176 IBM AIX PS/2 i[3456]86-*-aix
5177 Fujitsu FR30 fr30-*-elf*
5178 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5179 Argonaut Risc Chip (ARC) arc-*-*
5180 i386 running Mach 3.0 i[3456]86-*-mach3*
5181 i386 running Mach i[3456]86-*-mach*
5182 i386 running OSF/1 i[3456]86-*osf1mk*
5183 HP/Apollo 68k Family m68*-apollo*-sysv*,
5185 m68*-hp-bsd*, m68*-hp-hpux*
5186 I960 with MON960 i960-*-coff
5188 * OBSOLETE languages
5190 CHILL, a Pascal like language used by telecommunications companies.
5192 * REMOVED configurations and files
5194 AMD 29k family via UDI a29k-amd-udi, udi29k
5195 A29K VxWorks a29k-*-vxworks
5196 AMD 29000 embedded, using EBMON a29k-none-none
5197 AMD 29000 embedded with COFF a29k-none-coff
5198 AMD 29000 embedded with a.out a29k-none-aout
5200 testsuite/gdb.hp/gdb.threads-hp/ directory
5202 * New command "set max-user-call-depth <nnn>"
5204 This command allows the user to limit the call depth of user-defined
5205 commands. The default is 1024.
5207 * Changes in FreeBSD/i386 native debugging.
5209 Support for the "generate-core-file" has been added.
5211 * New commands "dump", "append", and "restore".
5213 These commands allow data to be copied from target memory
5214 to a bfd-format or binary file (dump and append), and back
5215 from a file into memory (restore).
5217 * Improved "next/step" support on multi-processor Alpha Tru64.
5219 The previous single-step mechanism could cause unpredictable problems,
5220 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5221 of a software single-step mechanism prevents this.
5223 *** Changes in GDB 5.2.1:
5231 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5232 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5233 Fix, by Joel Brobecker imported from mainline.
5235 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5236 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5237 Fix, by Fred Fish, imported from mainline.
5239 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5240 Surprisingly enough, it works now.
5241 By Michal Ludvig, imported from mainline.
5243 i386 hardware watchpoint support:
5244 avoid misses on second run for some targets.
5245 By Pierre Muller, imported from mainline.
5247 *** Changes in GDB 5.2:
5249 * New command "set trust-readonly-sections on[off]".
5251 This command is a hint that tells gdb that read-only sections
5252 really are read-only (ie. that their contents will not change).
5253 In this mode, gdb will go to the object file rather than the
5254 target to read memory from read-only sections (such as ".text").
5255 This can be a significant performance improvement on some
5256 (notably embedded) targets.
5258 * New command "generate-core-file" (or "gcore").
5260 This new gdb command allows the user to drop a core file of the child
5261 process state at any time. So far it's been implemented only for
5262 GNU/Linux and Solaris, but should be relatively easily ported to other
5263 hosts. Argument is core file name (defaults to core.<pid>).
5265 * New command line option
5267 GDB now accepts --pid or -p followed by a process id.
5269 * Change in command line behavior -- corefiles vs. process ids.
5271 There is a subtle behavior in the way in which GDB handles
5272 command line arguments. The first non-flag argument is always
5273 a program to debug, but the second non-flag argument may either
5274 be a corefile or a process id. Previously, GDB would attempt to
5275 open the second argument as a corefile, and if that failed, would
5276 issue a superfluous error message and then attempt to attach it as
5277 a process. Now, if the second argument begins with a non-digit,
5278 it will be treated as a corefile. If it begins with a digit,
5279 GDB will attempt to attach it as a process, and if no such process
5280 is found, will then attempt to open it as a corefile.
5282 * Changes in ARM configurations.
5284 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5285 configuration is fully multi-arch.
5287 * New native configurations
5289 ARM NetBSD arm*-*-netbsd*
5290 x86 OpenBSD i[3456]86-*-openbsd*
5291 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5292 Sparc64 running FreeBSD sparc64-*-freebsd*
5296 Sanyo XStormy16 xstormy16-elf
5298 * OBSOLETE configurations and files
5300 Configurations that have been declared obsolete in this release have
5301 been commented out. Unless there is activity to revive these
5302 configurations, the next release of GDB will have their sources
5303 permanently REMOVED.
5305 AMD 29k family via UDI a29k-amd-udi, udi29k
5306 A29K VxWorks a29k-*-vxworks
5307 AMD 29000 embedded, using EBMON a29k-none-none
5308 AMD 29000 embedded with COFF a29k-none-coff
5309 AMD 29000 embedded with a.out a29k-none-aout
5311 testsuite/gdb.hp/gdb.threads-hp/ directory
5313 * REMOVED configurations and files
5315 TI TMS320C80 tic80-*-*
5317 PowerPC Solaris powerpcle-*-solaris*
5318 PowerPC Windows NT powerpcle-*-cygwin32
5319 PowerPC Netware powerpc-*-netware*
5320 Harris/CXUX m88k m88*-harris-cxux*
5321 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5322 ns32k-utek-sysv* ns32k-utek-*
5323 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5324 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5325 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5326 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5327 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5329 * Changes to command line processing
5331 The new `--args' feature can be used to specify command-line arguments
5332 for the inferior from gdb's command line.
5334 * Changes to key bindings
5336 There is a new `operate-and-get-next' function bound to `C-o'.
5338 *** Changes in GDB 5.1.1
5340 Fix compile problem on DJGPP.
5342 Fix a problem with floating-point registers on the i386 being
5345 Fix to stop GDB crashing on .debug_str debug info.
5347 Numerous documentation fixes.
5349 Numerous testsuite fixes.
5351 *** Changes in GDB 5.1:
5353 * New native configurations
5355 Alpha FreeBSD alpha*-*-freebsd*
5356 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5357 MIPS GNU/Linux mips*-*-linux*
5358 MIPS SGI Irix 6.x mips*-sgi-irix6*
5359 ia64 AIX ia64-*-aix*
5360 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5364 Motorola 68HC11 and 68HC12 m68hc11-elf
5366 UltraSparc running GNU/Linux sparc64-*-linux*
5368 * OBSOLETE configurations and files
5370 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5371 Harris/CXUX m88k m88*-harris-cxux*
5372 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5373 ns32k-utek-sysv* ns32k-utek-*
5374 TI TMS320C80 tic80-*-*
5376 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5377 PowerPC Solaris powerpcle-*-solaris*
5378 PowerPC Windows NT powerpcle-*-cygwin32
5379 PowerPC Netware powerpc-*-netware*
5380 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5381 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5382 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5383 Apple Macintosh (MPW) host N/A
5385 stuff.c (Program to stuff files into a specially prepared space in kdb)
5386 kdb-start.c (Main loop for the standalone kernel debugger)
5388 Configurations that have been declared obsolete in this release have
5389 been commented out. Unless there is activity to revive these
5390 configurations, the next release of GDB will have their sources
5391 permanently REMOVED.
5393 * REMOVED configurations and files
5395 Altos 3068 m68*-altos-*
5396 Convex c1-*-*, c2-*-*
5398 ARM RISCix arm-*-* (as host)
5402 * GDB has been converted to ISO C.
5404 GDB's source code has been converted to ISO C. In particular, the
5405 sources are fully protoized, and rely on standard headers being
5410 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5412 * The MI enabled by default.
5414 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5415 revised and enabled by default. Packages which use GDB as a debugging
5416 engine behind a UI or another front end are encouraged to switch to
5417 using the GDB/MI interface, instead of the old annotations interface
5418 which is now deprecated.
5420 * Support for debugging Pascal programs.
5422 GDB now includes support for debugging Pascal programs. The following
5423 main features are supported:
5425 - Pascal-specific data types such as sets;
5427 - automatic recognition of Pascal sources based on file-name
5430 - Pascal-style display of data types, variables, and functions;
5432 - a Pascal expression parser.
5434 However, some important features are not yet supported.
5436 - Pascal string operations are not supported at all;
5438 - there are some problems with boolean types;
5440 - Pascal type hexadecimal constants are not supported
5441 because they conflict with the internal variables format;
5443 - support for Pascal objects and classes is not full yet;
5445 - unlike Pascal, GDB is case-sensitive for symbol names.
5447 * Changes in completion.
5449 Commands such as `shell', `run' and `set args', which pass arguments
5450 to inferior programs, now complete on file names, similar to what
5451 users expect at the shell prompt.
5453 Commands which accept locations, such as `disassemble', `print',
5454 `breakpoint', `until', etc. now complete on filenames as well as
5455 program symbols. Thus, if you type "break foob TAB", and the source
5456 files linked into the programs include `foobar.c', that file name will
5457 be one of the candidates for completion. However, file names are not
5458 considered for completion after you typed a colon that delimits a file
5459 name from a name of a function in that file, as in "break foo.c:bar".
5461 `set demangle-style' completes on available demangling styles.
5463 * New platform-independent commands:
5465 It is now possible to define a post-hook for a command as well as a
5466 hook that runs before the command. For more details, see the
5467 documentation of `hookpost' in the GDB manual.
5469 * Changes in GNU/Linux native debugging.
5471 Support for debugging multi-threaded programs has been completely
5472 revised for all platforms except m68k and sparc. You can now debug as
5473 many threads as your system allows you to have.
5475 Attach/detach is supported for multi-threaded programs.
5477 Support for SSE registers was added for x86. This doesn't work for
5478 multi-threaded programs though.
5480 * Changes in MIPS configurations.
5482 Multi-arch support is enabled for all MIPS configurations.
5484 GDB can now be built as native debugger on SGI Irix 6.x systems for
5485 debugging n32 executables. (Debugging 64-bit executables is not yet
5488 * Unified support for hardware watchpoints in all x86 configurations.
5490 Most (if not all) native x86 configurations support hardware-assisted
5491 breakpoints and watchpoints in a unified manner. This support
5492 implements debug register sharing between watchpoints, which allows to
5493 put a virtually infinite number of watchpoints on the same address,
5494 and also supports watching regions up to 16 bytes with several debug
5497 The new maintenance command `maintenance show-debug-regs' toggles
5498 debugging print-outs in functions that insert, remove, and test
5499 watchpoints and hardware breakpoints.
5501 * Changes in the DJGPP native configuration.
5503 New command ``info dos sysinfo'' displays assorted information about
5504 the CPU, OS, memory, and DPMI server.
5506 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5507 display information about segment descriptors stored in GDT, LDT, and
5510 New commands ``info dos pde'' and ``info dos pte'' display entries
5511 from Page Directory and Page Tables (for now works with CWSDPMI only).
5512 New command ``info dos address-pte'' displays the Page Table entry for
5513 a given linear address.
5515 GDB can now pass command lines longer than 126 characters to the
5516 program being debugged (requires an update to the libdbg.a library
5517 which is part of the DJGPP development kit).
5519 DWARF2 debug info is now supported.
5521 It is now possible to `step' and `next' through calls to `longjmp'.
5523 * Changes in documentation.
5525 All GDB documentation was converted to GFDL, the GNU Free
5526 Documentation License.
5528 Tracepoints-related commands are now fully documented in the GDB
5531 TUI, the Text-mode User Interface, is now documented in the manual.
5533 Tracepoints-related commands are now fully documented in the GDB
5536 The "GDB Internals" manual now has an index. It also includes
5537 documentation of `ui_out' functions, GDB coding standards, x86
5538 hardware watchpoints, and memory region attributes.
5540 * GDB's version number moved to ``version.in''
5542 The Makefile variable VERSION has been replaced by the file
5543 ``version.in''. People creating GDB distributions should update the
5544 contents of this file.
5548 GUD support is now a standard part of the EMACS distribution.
5550 *** Changes in GDB 5.0:
5552 * Improved support for debugging FP programs on x86 targets
5554 Unified and much-improved support for debugging floating-point
5555 programs on all x86 targets. In particular, ``info float'' now
5556 displays the FP registers in the same format on all x86 targets, with
5557 greater level of detail.
5559 * Improvements and bugfixes in hardware-assisted watchpoints
5561 It is now possible to watch array elements, struct members, and
5562 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5563 on x86 targets no longer erroneously trigger when the address is
5566 * Improvements in the native DJGPP version of GDB
5568 The distribution now includes all the scripts and auxiliary files
5569 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5570 machines ``out of the box''.
5572 The DJGPP version can now debug programs that use signals. It is
5573 possible to catch signals that happened in the debuggee, deliver
5574 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5575 would kill the program being debugged.) Programs that hook hardware
5576 interrupts (keyboard, timer, etc.) can also be debugged.
5578 It is now possible to debug DJGPP programs that redirect their
5579 standard handles or switch them to raw (as opposed to cooked) mode, or
5580 even close them. The command ``run < foo > bar'' works as expected,
5581 and ``info terminal'' reports useful information about the debuggee's
5582 terminal, including raw/cooked mode, redirection, etc.
5584 The DJGPP version now uses termios functions for console I/O, which
5585 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5588 DOS-style file names with drive letters are now fully supported by
5591 It is now possible to debug DJGPP programs that switch their working
5592 directory. It is also possible to rerun the debuggee any number of
5593 times without restarting GDB; thus, you can use the same setup,
5594 breakpoints, etc. for many debugging sessions.
5596 * New native configurations
5598 ARM GNU/Linux arm*-*-linux*
5599 PowerPC GNU/Linux powerpc-*-linux*
5603 Motorola MCore mcore-*-*
5604 x86 VxWorks i[3456]86-*-vxworks*
5605 PowerPC VxWorks powerpc-*-vxworks*
5606 TI TMS320C80 tic80-*-*
5608 * OBSOLETE configurations
5610 Altos 3068 m68*-altos-*
5611 Convex c1-*-*, c2-*-*
5613 ARM RISCix arm-*-* (as host)
5616 Configurations that have been declared obsolete will be commented out,
5617 but the code will be left in place. If there is no activity to revive
5618 these configurations before the next release of GDB, the sources will
5619 be permanently REMOVED.
5621 * Gould support removed
5623 Support for the Gould PowerNode and NP1 has been removed.
5625 * New features for SVR4
5627 On SVR4 native platforms (such as Solaris), if you attach to a process
5628 without first loading a symbol file, GDB will now attempt to locate and
5629 load symbols from the running process's executable file.
5631 * Many C++ enhancements
5633 C++ support has been greatly improved. Overload resolution now works properly
5634 in almost all cases. RTTI support is on the way.
5636 * Remote targets can connect to a sub-program
5638 A popen(3) style serial-device has been added. This device starts a
5639 sub-process (such as a stand-alone simulator) and then communicates
5640 with that. The sub-program to run is specified using the syntax
5641 ``|<program> <args>'' vis:
5643 (gdb) set remotedebug 1
5644 (gdb) target extended-remote |mn10300-elf-sim program-args
5646 * MIPS 64 remote protocol
5648 A long standing bug in the mips64 remote protocol where by GDB
5649 expected certain 32 bit registers (ex SR) to be transfered as 32
5650 instead of 64 bits has been fixed.
5652 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5653 added to provide backward compatibility with older versions of GDB.
5655 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5657 The command ``set remotebinarydownload'' command has been replaced by
5658 ``set remote X-packet''. Other commands in ``set remote'' family
5659 include ``set remote P-packet''.
5661 * Breakpoint commands accept ranges.
5663 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5664 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5665 ``tracepoint passcount'' also accepts a range of tracepoints.
5667 * ``apropos'' command added.
5669 The ``apropos'' command searches through command names and
5670 documentation strings, printing out matches, making it much easier to
5671 try to find a command that does what you are looking for.
5675 A new machine oriented interface (MI) has been added to GDB. This
5676 interface is designed for debug environments running GDB as a separate
5677 process. This is part of the long term libGDB project. See the
5678 "GDB/MI" chapter of the GDB manual for further information. It can be
5679 enabled by configuring with:
5681 .../configure --enable-gdbmi
5683 *** Changes in GDB-4.18:
5685 * New native configurations
5687 HP-UX 10.20 hppa*-*-hpux10.20
5688 HP-UX 11.x hppa*-*-hpux11.0*
5689 M68K GNU/Linux m68*-*-linux*
5693 Fujitsu FR30 fr30-*-elf*
5694 Intel StrongARM strongarm-*-*
5695 Mitsubishi D30V d30v-*-*
5697 * OBSOLETE configurations
5699 Gould PowerNode, NP1 np1-*-*, pn-*-*
5701 Configurations that have been declared obsolete will be commented out,
5702 but the code will be left in place. If there is no activity to revive
5703 these configurations before the next release of GDB, the sources will
5704 be permanently REMOVED.
5708 As a compatibility experiment, GDB's source files buildsym.h and
5709 buildsym.c have been converted to pure standard C, no longer
5710 containing any K&R compatibility code. We believe that all systems in
5711 use today either come with a standard C compiler, or have a GCC port
5712 available. If this is not true, please report the affected
5713 configuration to bug-gdb@gnu.org immediately. See the README file for
5714 information about getting a standard C compiler if you don't have one
5719 GDB now uses readline 2.2.
5721 * set extension-language
5723 You can now control the mapping between filename extensions and source
5724 languages by using the `set extension-language' command. For instance,
5725 you can ask GDB to treat .c files as C++ by saying
5726 set extension-language .c c++
5727 The command `info extensions' lists all of the recognized extensions
5728 and their associated languages.
5730 * Setting processor type for PowerPC and RS/6000
5732 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5733 you can use the `set processor' command to specify what variant of the
5734 PowerPC family you are debugging. The command
5738 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5739 following PowerPC and RS6000 variants:
5741 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5742 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5744 403GC IBM PowerPC 403GC
5745 505 Motorola PowerPC 505
5746 860 Motorola PowerPC 860 or 850
5747 601 Motorola PowerPC 601
5748 602 Motorola PowerPC 602
5749 603 Motorola/IBM PowerPC 603 or 603e
5750 604 Motorola PowerPC 604 or 604e
5751 750 Motorola/IBM PowerPC 750 or 750
5753 At the moment, this command just tells GDB what to name the
5754 special-purpose processor registers. Since almost all the affected
5755 registers are inaccessible to user-level programs, this command is
5756 only useful for remote debugging in its present form.
5760 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5761 more extensive support for HP-UX. Added features include shared
5762 library support, kernel threads and hardware watchpoints for 11.00,
5763 support for HP's ANSI C and C++ compilers, and a compatibility mode
5764 for xdb and dbx commands.
5768 HP's donation includes the new concept of catchpoints, which is a
5769 generalization of the old catch command. On HP-UX, it is now possible
5770 to catch exec, fork, and vfork, as well as library loading.
5772 This means that the existing catch command has changed; its first
5773 argument now specifies the type of catch to be set up. See the
5774 output of "help catch" for a list of catchpoint types.
5776 * Debugging across forks
5778 On HP-UX, you can choose which process to debug when a fork() happens
5783 HP has donated a curses-based terminal user interface (TUI). To get
5784 it, build with --enable-tui. Although this can be enabled for any
5785 configuration, at present it only works for native HP debugging.
5787 * GDB remote protocol additions
5789 A new protocol packet 'X' that writes binary data is now available.
5790 Default behavior is to try 'X', then drop back to 'M' if the stub
5791 fails to respond. The settable variable `remotebinarydownload'
5792 allows explicit control over the use of 'X'.
5794 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5795 full 64-bit address. The command
5797 set remoteaddresssize 32
5799 can be used to revert to the old behaviour. For existing remote stubs
5800 the change should not be noticed, as the additional address information
5803 In order to assist in debugging stubs, you may use the maintenance
5804 command `packet' to send any text string to the stub. For instance,
5806 maint packet heythere
5808 sends the packet "$heythere#<checksum>". Note that it is very easy to
5809 disrupt a debugging session by sending the wrong packet at the wrong
5812 The compare-sections command allows you to compare section data on the
5813 target to what is in the executable file without uploading or
5814 downloading, by comparing CRC checksums.
5816 * Tracing can collect general expressions
5818 You may now collect general expressions at tracepoints. This requires
5819 further additions to the target-side stub; see tracepoint.c and
5820 doc/agentexpr.texi for further details.
5822 * mask-address variable for Mips
5824 For Mips targets, you may control the zeroing of the upper 32 bits of
5825 a 64-bit address by entering `set mask-address on'. This is mainly
5826 of interest to users of embedded R4xxx and R5xxx processors.
5828 * Higher serial baud rates
5830 GDB's serial code now allows you to specify baud rates 57600, 115200,
5831 230400, and 460800 baud. (Note that your host system may not be able
5832 to achieve all of these rates.)
5836 The i960 configuration now includes an initial implementation of a
5837 builtin simulator, contributed by Jim Wilson.
5840 *** Changes in GDB-4.17:
5842 * New native configurations
5844 Alpha GNU/Linux alpha*-*-linux*
5845 Unixware 2.x i[3456]86-unixware2*
5846 Irix 6.x mips*-sgi-irix6*
5847 PowerPC GNU/Linux powerpc-*-linux*
5848 PowerPC Solaris powerpcle-*-solaris*
5849 Sparc GNU/Linux sparc-*-linux*
5850 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5854 Argonaut Risc Chip (ARC) arc-*-*
5855 Hitachi H8/300S h8300*-*-*
5856 Matsushita MN10200 w/simulator mn10200-*-*
5857 Matsushita MN10300 w/simulator mn10300-*-*
5858 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5859 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5860 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5861 Mitsubishi D10V w/simulator d10v-*-*
5862 Mitsubishi M32R/D w/simulator m32r-*-elf*
5863 Tsqware Sparclet sparclet-*-*
5864 NEC V850 w/simulator v850-*-*
5866 * New debugging protocols
5868 ARM with RDI protocol arm*-*-*
5869 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5870 DDB and LSI variants of PMON protocol mips*-*-*
5871 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5872 PowerPC with SDS protocol powerpc{,le}-*-eabi
5873 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5877 All configurations can now understand and use the DWARF 2 debugging
5878 format. The choice is automatic, if the symbol file contains DWARF 2
5883 GDB now includes basic Java language support. This support is
5884 only useful with Java compilers that produce native machine code.
5886 * solib-absolute-prefix and solib-search-path
5888 For SunOS and SVR4 shared libraries, you may now set the prefix for
5889 loading absolute shared library symbol files, and the search path for
5890 locating non-absolute shared library symbol files.
5892 * Live range splitting
5894 GDB can now effectively debug code for which GCC has performed live
5895 range splitting as part of its optimization. See gdb/doc/LRS for
5896 more details on the expected format of the stabs information.
5900 GDB's support for the GNU Hurd, including thread debugging, has been
5901 updated to work with current versions of the Hurd.
5905 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5906 instruction set. ARM GDB automatically detects when Thumb
5907 instructions are in use, and adjusts disassembly and backtracing
5912 GDB's MIPS target configurations now handle the MIP16 16-bit
5917 GDB now includes support for overlays; if an executable has been
5918 linked such that multiple sections are based at the same address, GDB
5919 will decide which section to use for symbolic info. You can choose to
5920 control the decision manually, using overlay commands, or implement
5921 additional target-side support and use "overlay load-target" to bring
5922 in the overlay mapping. Do "help overlay" for more detail.
5926 The command "info symbol <address>" displays information about
5927 the symbol at the specified address.
5931 The standard remote protocol now includes an extension that allows
5932 asynchronous collection and display of trace data. This requires
5933 extensive support in the target-side debugging stub. Tracing mode
5934 includes a new interaction mode in GDB and new commands: see the
5935 file tracepoint.c for more details.
5939 Configurations for embedded MIPS now include a simulator contributed
5940 by Cygnus Solutions. The simulator supports the instruction sets
5941 of most MIPS variants.
5945 Sparc configurations may now include the ERC32 simulator contributed
5946 by the European Space Agency. The simulator is not built into
5947 Sparc targets by default; configure with --enable-sim to include it.
5951 For target configurations that may include multiple variants of a
5952 basic architecture (such as MIPS and SH), you may now set the
5953 architecture explicitly. "set arch" sets, "info arch" lists
5954 the possible architectures.
5956 *** Changes in GDB-4.16:
5958 * New native configurations
5960 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5961 M68K NetBSD m68k-*-netbsd*
5962 PowerPC AIX 4.x powerpc-*-aix*
5963 PowerPC MacOS powerpc-*-macos*
5964 PowerPC Windows NT powerpcle-*-cygwin32
5965 RS/6000 AIX 4.x rs6000-*-aix4*
5969 ARM with RDP protocol arm-*-*
5970 I960 with MON960 i960-*-coff
5971 MIPS VxWorks mips*-*-vxworks*
5972 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5973 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5975 Matra Sparclet sparclet-*-*
5979 The powerpc-eabi configuration now includes the PSIM simulator,
5980 contributed by Andrew Cagney, with assistance from Mike Meissner.
5981 PSIM is a very elaborate model of the PowerPC, including not only
5982 basic instruction set execution, but also details of execution unit
5983 performance and I/O hardware. See sim/ppc/README for more details.
5987 GDB now works with Solaris 2.5.
5989 * Windows 95/NT native
5991 GDB will now work as a native debugger on Windows 95 and Windows NT.
5992 To build it from source, you must use the "gnu-win32" environment,
5993 which uses a DLL to emulate enough of Unix to run the GNU tools.
5994 Further information, binaries, and sources are available at
5995 ftp.cygnus.com, under pub/gnu-win32.
5997 * dont-repeat command
5999 If a user-defined command includes the command `dont-repeat', then the
6000 command will not be repeated if the user just types return. This is
6001 useful if the command is time-consuming to run, so that accidental
6002 extra keystrokes don't run the same command many times.
6004 * Send break instead of ^C
6006 The standard remote protocol now includes an option to send a break
6007 rather than a ^C to the target in order to interrupt it. By default,
6008 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6010 * Remote protocol timeout
6012 The standard remote protocol includes a new variable `remotetimeout'
6013 that allows you to set the number of seconds before GDB gives up trying
6014 to read from the target. The default value is 2.
6016 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6018 By default GDB will automatically keep track of objects as they are
6019 loaded and unloaded by the dynamic linker. By using the command `set
6020 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6021 when shared library events occur, thus allowing you to set breakpoints
6022 in shared libraries which are explicitly loaded by the inferior.
6024 Note this feature does not work on hpux8. On hpux9 you must link
6025 /usr/lib/end.o into your program. This feature should work
6026 automatically on hpux10.
6028 * Irix 5.x hardware watchpoint support
6030 Irix 5 configurations now support the use of hardware watchpoints.
6032 * Mips protocol "SYN garbage limit"
6034 When debugging a Mips target using the `target mips' protocol, you
6035 may set the number of characters that GDB will ignore by setting
6036 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6037 every character. The default value is 1050.
6039 * Recording and replaying remote debug sessions
6041 If you set `remotelogfile' to the name of a file, gdb will write to it
6042 a recording of a remote debug session. This recording may then be
6043 replayed back to gdb using "gdbreplay". See gdbserver/README for
6044 details. This is useful when you have a problem with GDB while doing
6045 remote debugging; you can make a recording of the session and send it
6046 to someone else, who can then recreate the problem.
6048 * Speedups for remote debugging
6050 GDB includes speedups for downloading and stepping MIPS systems using
6051 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6052 and more efficient S-record downloading.
6054 * Memory use reductions and statistics collection
6056 GDB now uses less memory and reports statistics about memory usage.
6057 Try the `maint print statistics' command, for example.
6059 *** Changes in GDB-4.15:
6061 * Psymtabs for XCOFF
6063 The symbol reader for AIX GDB now uses partial symbol tables. This
6064 can greatly improve startup time, especially for large executables.
6066 * Remote targets use caching
6068 Remote targets now use a data cache to speed up communication with the
6069 remote side. The data cache could lead to incorrect results because
6070 it doesn't know about volatile variables, thus making it impossible to
6071 debug targets which use memory mapped I/O devices. `set remotecache
6072 off' turns the the data cache off.
6074 * Remote targets may have threads
6076 The standard remote protocol now includes support for multiple threads
6077 in the target system, using new protocol commands 'H' and 'T'. See
6078 gdb/remote.c for details.
6082 If GDB is configured with `--enable-netrom', then it will include
6083 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6084 acts as though it is a bank of ROM on the target board, but you can
6085 write into it over the network. GDB's support consists only of
6086 support for fast loading into the emulated ROM; to debug, you must use
6087 another protocol, such as standard remote protocol. The usual
6088 sequence is something like
6090 target nrom <netrom-hostname>
6092 target remote <netrom-hostname>:1235
6096 GDB now includes support for the Apple Macintosh, as a host only. It
6097 may be run as either an MPW tool or as a standalone application, and
6098 it can debug through the serial port. All the usual GDB commands are
6099 available, but to the target command, you must supply "serial" as the
6100 device type instead of "/dev/ttyXX". See mpw-README in the main
6101 directory for more information on how to build. The MPW configuration
6102 scripts */mpw-config.in support only a few targets, and only the
6103 mips-idt-ecoff target has been tested.
6107 GDB configuration now uses autoconf. This is not user-visible,
6108 but does simplify configuration and building.
6112 GDB now supports hpux10.
6114 *** Changes in GDB-4.14:
6116 * New native configurations
6118 x86 FreeBSD i[345]86-*-freebsd
6119 x86 NetBSD i[345]86-*-netbsd
6120 NS32k NetBSD ns32k-*-netbsd
6121 Sparc NetBSD sparc-*-netbsd
6125 A29K VxWorks a29k-*-vxworks
6126 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6127 CPU32 EST-300 emulator m68*-*-est*
6128 PowerPC ELF powerpc-*-elf
6131 * Alpha OSF/1 support for procfs
6133 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6134 possible to attach to running processes. As the mounting of the /proc
6135 filesystem is optional on the Alpha, GDB automatically determines
6136 the availability of /proc during startup. This can lead to problems
6137 if /proc is unmounted after GDB has been started.
6139 * Arguments to user-defined commands
6141 User commands may accept up to 10 arguments separated by whitespace.
6142 Arguments are accessed within the user command via $arg0..$arg9. A
6145 print $arg0 + $arg1 + $arg2
6147 To execute the command use:
6150 Defines the command "adder" which prints the sum of its three arguments.
6151 Note the arguments are text substitutions, so they may reference variables,
6152 use complex expressions, or even perform inferior function calls.
6154 * New `if' and `while' commands
6156 This makes it possible to write more sophisticated user-defined
6157 commands. Both commands take a single argument, which is the
6158 expression to evaluate, and must be followed by the commands to
6159 execute, one per line, if the expression is nonzero, the list being
6160 terminated by the word `end'. The `if' command list may include an
6161 `else' word, which causes the following commands to be executed only
6162 if the expression is zero.
6164 * Fortran source language mode
6166 GDB now includes partial support for Fortran 77. It will recognize
6167 Fortran programs and can evaluate a subset of Fortran expressions, but
6168 variables and functions may not be handled correctly. GDB will work
6169 with G77, but does not yet know much about symbols emitted by other
6172 * Better HPUX support
6174 Most debugging facilities now work on dynamic executables for HPPAs
6175 running hpux9 or later. You can attach to running dynamically linked
6176 processes, but by default the dynamic libraries will be read-only, so
6177 for instance you won't be able to put breakpoints in them. To change
6178 that behavior do the following before running the program:
6184 This will cause the libraries to be mapped private and read-write.
6185 To revert to the normal behavior, do this:
6191 You cannot set breakpoints or examine data in the library until after
6192 the library is loaded if the function/data symbols do not have
6195 GDB can now also read debug symbols produced by the HP C compiler on
6196 HPPAs (sorry, no C++, Fortran or 68k support).
6198 * Target byte order now dynamically selectable
6200 You can choose which byte order to use with a target system, via the
6201 commands "set endian big" and "set endian little", and you can see the
6202 current setting by using "show endian". You can also give the command
6203 "set endian auto", in which case GDB will use the byte order
6204 associated with the executable. Currently, only embedded MIPS
6205 configurations support dynamic selection of target byte order.
6207 * New DOS host serial code
6209 This version uses DPMI interrupts to handle buffered I/O, so you
6210 no longer need to run asynctsr when debugging boards connected to
6213 *** Changes in GDB-4.13:
6215 * New "complete" command
6217 This lists all the possible completions for the rest of the line, if it
6218 were to be given as a command itself. This is intended for use by emacs.
6220 * Trailing space optional in prompt
6222 "set prompt" no longer adds a space for you after the prompt you set. This
6223 allows you to set a prompt which ends in a space or one that does not.
6225 * Breakpoint hit counts
6227 "info break" now displays a count of the number of times the breakpoint
6228 has been hit. This is especially useful in conjunction with "ignore"; you
6229 can ignore a large number of breakpoint hits, look at the breakpoint info
6230 to see how many times the breakpoint was hit, then run again, ignoring one
6231 less than that number, and this will get you quickly to the last hit of
6234 * Ability to stop printing at NULL character
6236 "set print null-stop" will cause GDB to stop printing the characters of
6237 an array when the first NULL is encountered. This is useful when large
6238 arrays actually contain only short strings.
6240 * Shared library breakpoints
6242 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6243 breakpoints in shared libraries before the executable is run.
6245 * Hardware watchpoints
6247 There is a new hardware breakpoint for the watch command for sparclite
6248 targets. See gdb/sparclite/hw_breakpoint.note.
6250 Hardware watchpoints are also now supported under GNU/Linux.
6254 Annotations have been added. These are for use with graphical interfaces,
6255 and are still experimental. Currently only gdba.el uses these.
6257 * Improved Irix 5 support
6259 GDB now works properly with Irix 5.2.
6261 * Improved HPPA support
6263 GDB now works properly with the latest GCC and GAS.
6265 * New native configurations
6267 Sequent PTX4 i[34]86-sequent-ptx4
6268 HPPA running OSF/1 hppa*-*-osf*
6269 Atari TT running SVR4 m68*-*-sysv4*
6270 RS/6000 LynxOS rs6000-*-lynxos*
6274 OS/9000 i[34]86-*-os9k
6275 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6278 * Hitachi SH7000 and E7000-PC ICE support
6280 There is now support for communicating with the Hitachi E7000-PC ICE.
6281 This is available automatically when GDB is configured for the SH.
6285 As usual, a variety of small fixes and improvements, both generic
6286 and configuration-specific. See the ChangeLog for more detail.
6288 *** Changes in GDB-4.12:
6290 * Irix 5 is now supported
6294 GDB-4.12 on the HPPA has a number of changes which make it unable
6295 to debug the output from the currently released versions of GCC and
6296 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6297 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6298 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6301 *** Changes in GDB-4.11:
6303 * User visible changes:
6307 The "set remotedebug" option is now consistent between the mips remote
6308 target, remote targets using the gdb-specific protocol, UDI (AMD's
6309 debug protocol for the 29k) and the 88k bug monitor. It is now an
6310 integer specifying a debug level (normally 0 or 1, but 2 means more
6311 debugging info for the mips target).
6313 * DEC Alpha native support
6315 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6316 debug info, but GDB works fairly well with the DEC compiler and should
6317 work with a future GCC release. See the README file for a few
6318 Alpha-specific notes.
6320 * Preliminary thread implementation
6322 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6324 * LynxOS native and target support for 386
6326 This release has been hosted on LynxOS 2.2, and also can be configured
6327 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6330 * Improvements in C++ mangling/demangling.
6332 This release has much better g++ debugging, specifically in name
6333 mangling/demangling, virtual function calls, print virtual table,
6334 call methods, ...etc.
6336 *** Changes in GDB-4.10:
6338 * User visible changes:
6340 Remote debugging using the GDB-specific (`target remote') protocol now
6341 supports the `load' command. This is only useful if you have some
6342 other way of getting the stub to the target system, and you can put it
6343 somewhere in memory where it won't get clobbered by the download.
6345 Filename completion now works.
6347 When run under emacs mode, the "info line" command now causes the
6348 arrow to point to the line specified. Also, "info line" prints
6349 addresses in symbolic form (as well as hex).
6351 All vxworks based targets now support a user settable option, called
6352 vxworks-timeout. This option represents the number of seconds gdb
6353 should wait for responses to rpc's. You might want to use this if
6354 your vxworks target is, perhaps, a slow software simulator or happens
6355 to be on the far side of a thin network line.
6359 This release contains support for using a DEC alpha as a GDB host for
6360 cross debugging. Native alpha debugging is not supported yet.
6363 *** Changes in GDB-4.9:
6367 This is the first GDB release which is accompanied by a matching testsuite.
6368 The testsuite requires installation of dejagnu, which should be available
6369 via ftp from most sites that carry GNU software.
6373 'Cfront' style demangling has had its name changed to 'ARM' style, to
6374 emphasize that it was written from the specifications in the C++ Annotated
6375 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6376 disclaimers, it still generated too much confusion with users attempting to
6377 use gdb with AT&T cfront.
6381 GDB now uses a standard remote interface to a simulator library.
6382 So far, the library contains simulators for the Zilog Z8001/2, the
6383 Hitachi H8/300, H8/500 and Super-H.
6385 * New targets supported
6387 H8/300 simulator h8300-hitachi-hms or h8300hms
6388 H8/500 simulator h8500-hitachi-hms or h8500hms
6389 SH simulator sh-hitachi-hms or sh
6390 Z8000 simulator z8k-zilog-none or z8ksim
6391 IDT MIPS board over serial line mips-idt-ecoff
6393 Cross-debugging to GO32 targets is supported. It requires a custom
6394 version of the i386-stub.c module which is integrated with the
6395 GO32 memory extender.
6397 * New remote protocols
6399 MIPS remote debugging protocol.
6401 * New source languages supported
6403 This version includes preliminary support for Chill, a Pascal like language
6404 used by telecommunications companies. Chill support is also being integrated
6405 into the GNU compiler, but we don't know when it will be publically available.
6408 *** Changes in GDB-4.8:
6410 * HP Precision Architecture supported
6412 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6413 version of this support was available as a set of patches from the
6414 University of Utah. GDB does not support debugging of programs
6415 compiled with the HP compiler, because HP will not document their file
6416 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6417 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6419 Many problems in the preliminary version have been fixed.
6421 * Faster and better demangling
6423 We have improved template demangling and fixed numerous bugs in the GNU style
6424 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6425 character types (wchar_t) are now supported. Demangling of each symbol is now
6426 only done once, and is cached when the symbol table for a file is read in.
6427 This results in a small increase in memory usage for C programs, a moderate
6428 increase in memory usage for C++ programs, and a fantastic speedup in
6431 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6432 from the specifications in the Annotated Reference Manual, which AT&T's
6433 compiler does not actually implement.
6435 * G++ multiple inheritance compiler problem
6437 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6438 inheritance lattices was reworked to properly discover ambiguities. We
6439 recently found an example which causes this new algorithm to fail in a
6440 very subtle way, producing bad debug information for those classes.
6441 The file 'gcc.patch' (in this directory) can be applied to gcc to
6442 circumvent the problem. A future GCC release will contain a complete
6445 The previous G++ debug info problem (mentioned below for the gdb-4.7
6446 release) is fixed in gcc version 2.3.2.
6448 * Improved configure script
6450 The `configure' script will now attempt to guess your system type if
6451 you don't supply a host system type. The old scheme of supplying a
6452 host system triplet is preferable over using this. All the magic is
6453 done in the new `config.guess' script. Examine it for details.
6455 We have also brought our configure script much more in line with the FSF's
6456 version. It now supports the --with-xxx options. In particular,
6457 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6458 The resulting GDB will not be able to read arbitrary object file formats --
6459 only the format ``expected'' to be used on the configured target system.
6460 We hope to make this the default in a future release.
6462 * Documentation improvements
6464 There's new internal documentation on how to modify GDB, and how to
6465 produce clean changes to the code. We implore people to read it
6466 before submitting changes.
6468 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6469 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6470 `info' files are also provided. To build `info' files from scratch,
6471 you will need the latest `makeinfo' release, which will be available in
6472 a future texinfo-X.Y release.
6474 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6475 We're not sure exactly which versions have this problem, but it has
6476 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6477 or better. If that isn't possible, there is a patch in
6478 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6479 around this problem.
6483 GDB now supports array constants that can be used in expressions typed in by
6484 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6485 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6488 The new directory `gdb/sparclite' contains a program that demonstrates
6489 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6491 * New native hosts supported
6493 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6494 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6496 * New targets supported
6498 AMD 29k family via UDI a29k-amd-udi or udi29k
6500 * New file formats supported
6502 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6503 HPUX core files, and SCO 3.2v2 core files.
6507 Attaching to processes now works again; thanks for the many bug reports.
6509 We have also stomped on a bunch of core dumps caused by
6510 printf_filtered("%s") problems.
6512 We eliminated a copyright problem on the rpc and ptrace header files
6513 for VxWorks, which was discovered at the last minute during the 4.7
6514 release. You should now be able to build a VxWorks GDB.
6516 You can now interrupt gdb while an attached process is running. This
6517 will cause the attached process to stop, and give control back to GDB.
6519 We fixed problems caused by using too many file descriptors
6520 for reading symbols from object files and libraries. This was
6521 especially a problem for programs that used many (~100) shared
6524 The `step' command now only enters a subroutine if there is line number
6525 information for the subroutine. Otherwise it acts like the `next'
6526 command. Previously, `step' would enter subroutines if there was
6527 any debugging information about the routine. This avoids problems
6528 when using `cc -g1' on MIPS machines.
6530 * Internal improvements
6532 GDB's internal interfaces have been improved to make it easier to support
6533 debugging of multiple languages in the future.
6535 GDB now uses a common structure for symbol information internally.
6536 Minimal symbols (derived from linkage symbols in object files), partial
6537 symbols (from a quick scan of debug information), and full symbols
6538 contain a common subset of information, making it easier to write
6539 shared code that handles any of them.
6541 * New command line options
6543 We now accept --silent as an alias for --quiet.
6547 The memory-mapped-malloc library is now licensed under the GNU Library
6548 General Public License.
6550 *** Changes in GDB-4.7:
6552 * Host/native/target split
6554 GDB has had some major internal surgery to untangle the support for
6555 hosts and remote targets. Now, when you configure GDB for a remote
6556 target, it will no longer load in all of the support for debugging
6557 local programs on the host. When fully completed and tested, this will
6558 ensure that arbitrary host/target combinations are possible.
6560 The primary conceptual shift is to separate the non-portable code in
6561 GDB into three categories. Host specific code is required any time GDB
6562 is compiled on that host, regardless of the target. Target specific
6563 code relates to the peculiarities of the target, but can be compiled on
6564 any host. Native specific code is everything else: it can only be
6565 built when the host and target are the same system. Child process
6566 handling and core file support are two common `native' examples.
6568 GDB's use of /proc for controlling Unix child processes is now cleaner.
6569 It has been split out into a single module under the `target_ops' vector,
6570 plus two native-dependent functions for each system that uses /proc.
6572 * New hosts supported
6574 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6575 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6576 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6578 * New targets supported
6580 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6581 68030 and CPU32 m68030-*-*, m68332-*-*
6583 * New native hosts supported
6585 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6586 (386bsd is not well tested yet)
6587 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6589 * New file formats supported
6591 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6592 supports reading of `a.out.adobe' object files, which are an a.out
6593 format extended with minimal information about multiple sections.
6597 `show copying' is the same as the old `info copying'.
6598 `show warranty' is the same as `info warrantee'.
6599 These were renamed for consistency. The old commands continue to work.
6601 `info handle' is a new alias for `info signals'.
6603 You can now define pre-command hooks, which attach arbitrary command
6604 scripts to any command. The commands in the hook will be executed
6605 prior to the user's command. You can also create a hook which will be
6606 executed whenever the program stops. See gdb.texinfo.
6610 We now deal with Cfront style name mangling, and can even extract type
6611 info from mangled symbols. GDB can automatically figure out which
6612 symbol mangling style your C++ compiler uses.
6614 Calling of methods and virtual functions has been improved as well.
6618 The crash that occured when debugging Sun Ansi-C compiled binaries is
6619 fixed. This was due to mishandling of the extra N_SO stabs output
6622 We also finally got Ultrix 4.2 running in house, and fixed core file
6623 support, with help from a dozen people on the net.
6625 John M. Farrell discovered that the reason that single-stepping was so
6626 slow on all of the Mips based platforms (primarily SGI and DEC) was
6627 that we were trying to demangle and lookup a symbol used for internal
6628 purposes on every instruction that was being stepped through. Changing
6629 the name of that symbol so that it couldn't be mistaken for a C++
6630 mangled symbol sped things up a great deal.
6632 Rich Pixley sped up symbol lookups in general by getting much smarter
6633 about when C++ symbol mangling is necessary. This should make symbol
6634 completion (TAB on the command line) much faster. It's not as fast as
6635 we'd like, but it's significantly faster than gdb-4.6.
6639 A new user controllable variable 'call_scratch_address' can
6640 specify the location of a scratch area to be used when GDB
6641 calls a function in the target. This is necessary because the
6642 usual method of putting the scratch area on the stack does not work
6643 in systems that have separate instruction and data spaces.
6645 We integrated changes to support the 29k UDI (Universal Debugger
6646 Interface), but discovered at the last minute that we didn't have all
6647 of the appropriate copyright paperwork. We are working with AMD to
6648 resolve this, and hope to have it available soon.
6652 We have sped up the remote serial line protocol, especially for targets
6653 with lots of registers. It now supports a new `expedited status' ('T')
6654 message which can be used in place of the existing 'S' status message.
6655 This allows the remote stub to send only the registers that GDB
6656 needs to make a quick decision about single-stepping or conditional
6657 breakpoints, eliminating the need to fetch the entire register set for
6658 each instruction being stepped through.
6660 The GDB remote serial protocol now implements a write-through cache for
6661 registers, only re-reading the registers if the target has run.
6663 There is also a new remote serial stub for SPARC processors. You can
6664 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6665 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6666 processor with a serial port.
6670 Configure.in files have become much easier to read and modify. A new
6671 `table driven' format makes it more obvious what configurations are
6672 supported, and what files each one uses.
6676 There is a new opcodes library which will eventually contain all of the
6677 disassembly routines and opcode tables. At present, it only contains
6678 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6679 disassembler (binutils/objdump) to share these routines.
6681 The libiberty library is now copylefted under the GNU Library General
6682 Public License. This allows more liberal use, and was done so libg++
6683 can use it. This makes no difference to GDB, since the Library License
6684 grants all the rights from the General Public License.
6688 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6689 reference to the stabs symbol info used by the debugger. It is (as far
6690 as we know) the only published document on this fascinating topic. We
6691 encourage you to read it, compare it to the stabs information on your
6692 system, and send improvements on the document in general (to
6693 bug-gdb@prep.ai.mit.edu).
6695 And, of course, many bugs have been fixed.
6698 *** Changes in GDB-4.6:
6700 * Better support for C++ function names
6702 GDB now accepts as input the "demangled form" of C++ overloaded function
6703 names and member function names, and can do command completion on such names
6704 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6705 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6706 Make use of command completion, it is your friend.
6708 GDB also now accepts a variety of C++ mangled symbol formats. They are
6709 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6710 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6711 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6712 for the list of formats.
6714 * G++ symbol mangling problem
6716 Recent versions of gcc have a bug in how they emit debugging information for
6717 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6718 directory) can be applied to gcc to fix the problem. Alternatively, if you
6719 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6720 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6721 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6724 * New 'maintenance' command
6726 All of the commands related to hacking GDB internals have been moved out of
6727 the main command set, and now live behind the 'maintenance' command. This
6728 can also be abbreviated as 'mt'. The following changes were made:
6730 dump-me -> maintenance dump-me
6731 info all-breakpoints -> maintenance info breakpoints
6732 printmsyms -> maintenance print msyms
6733 printobjfiles -> maintenance print objfiles
6734 printpsyms -> maintenance print psymbols
6735 printsyms -> maintenance print symbols
6737 The following commands are new:
6739 maintenance demangle Call internal GDB demangler routine to
6740 demangle a C++ link name and prints the result.
6741 maintenance print type Print a type chain for a given symbol
6743 * Change to .gdbinit file processing
6745 We now read the $HOME/.gdbinit file before processing the argv arguments
6746 (e.g. reading symbol files or core files). This allows global parameters to
6747 be set, which will apply during the symbol reading. The ./.gdbinit is still
6748 read after argv processing.
6750 * New hosts supported
6752 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6754 GNU/Linux support i386-unknown-linux or linux
6756 We are also including code to support the HP/PA running BSD and HPUX. This
6757 is almost guaranteed not to work, as we didn't have time to test or build it
6758 for this release. We are including it so that the more adventurous (or
6759 masochistic) of you can play with it. We also had major problems with the
6760 fact that the compiler that we got from HP doesn't support the -g option.
6763 * New targets supported
6765 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6767 * More smarts about finding #include files
6769 GDB now remembers the compilation directory for all include files, and for
6770 all files from which C is generated (like yacc and lex sources). This
6771 greatly improves GDB's ability to find yacc/lex sources, and include files,
6772 especially if you are debugging your program from a directory different from
6773 the one that contains your sources.
6775 We also fixed a bug which caused difficulty with listing and setting
6776 breakpoints in include files which contain C code. (In the past, you had to
6777 try twice in order to list an include file that you hadn't looked at before.)
6779 * Interesting infernals change
6781 GDB now deals with arbitrary numbers of sections, where the symbols for each
6782 section must be relocated relative to that section's landing place in the
6783 target's address space. This work was needed to support ELF with embedded
6784 stabs used by Solaris-2.0.
6786 * Bug fixes (of course!)
6788 There have been loads of fixes for the following things:
6789 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6790 i960, stabs, DOS(GO32), procfs, etc...
6792 See the ChangeLog for details.
6794 *** Changes in GDB-4.5:
6796 * New machines supported (host and target)
6798 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6800 SGI Irix-4.x mips-sgi-irix4 or iris4
6802 * New malloc package
6804 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6805 Mmalloc is capable of handling mutiple heaps of memory. It is also
6806 capable of saving a heap to a file, and then mapping it back in later.
6807 This can be used to greatly speedup the startup of GDB by using a
6808 pre-parsed symbol table which lives in a mmalloc managed heap. For
6809 more details, please read mmalloc/mmalloc.texi.
6813 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6814 'help info proc' for details.
6816 * MIPS ecoff symbol table format
6818 The code that reads MIPS symbol table format is now supported on all hosts.
6819 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6822 * File name changes for MS-DOS
6824 Many files in the config directories have been renamed to make it easier to
6825 support GDB on MS-DOSe systems (which have very restrictive file name
6826 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6827 environment) is close to working but has some remaining problems. Note
6828 that debugging of DOS programs is not supported, due to limitations
6829 in the ``operating system'', but it can be used to host cross-debugging.
6831 * Cross byte order fixes
6833 Many fixes have been made to support cross debugging of Sparc and MIPS
6834 targets from hosts whose byte order differs.
6836 * New -mapped and -readnow options
6838 If memory-mapped files are available on your system through the 'mmap'
6839 system call, you can use the -mapped option on the `file' or
6840 `symbol-file' commands to cause GDB to write the symbols from your
6841 program into a reusable file. If the program you are debugging is
6842 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6843 Future GDB debugging sessions will notice the presence of this file,
6844 and will quickly map in symbol information from it, rather than reading
6845 the symbol table from the executable program. Using the '-mapped'
6846 option in a GDB `file' or `symbol-file' command has the same effect as
6847 starting GDB with the '-mapped' command-line option.
6849 You can cause GDB to read the entire symbol table immediately by using
6850 the '-readnow' option with any of the commands that load symbol table
6851 information (or on the GDB command line). This makes the command
6852 slower, but makes future operations faster.
6854 The -mapped and -readnow options are typically combined in order to
6855 build a `fred.syms' file that contains complete symbol information.
6856 A simple GDB invocation to do nothing but build a `.syms' file for future
6859 gdb -batch -nx -mapped -readnow programname
6861 The `.syms' file is specific to the host machine on which GDB is run.
6862 It holds an exact image of GDB's internal symbol table. It cannot be
6863 shared across multiple host platforms.
6865 * longjmp() handling
6867 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6868 siglongjmp() without losing control. This feature has not yet been ported to
6869 all systems. It currently works on many 386 platforms, all MIPS-based
6870 platforms (SGI, DECstation, etc), and Sun3/4.
6874 Preliminary work has been put in to support the new Solaris OS from Sun. At
6875 this time, it can control and debug processes, but it is not capable of
6880 As always, many many bug fixes. The major areas were with g++, and mipsread.
6881 People using the MIPS-based platforms should experience fewer mysterious
6882 crashes and trashed symbol tables.
6884 *** Changes in GDB-4.4:
6886 * New machines supported (host and target)
6888 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6890 BSD Reno on Vax vax-dec-bsd
6891 Ultrix on Vax vax-dec-ultrix
6893 * New machines supported (target)
6895 AMD 29000 embedded, using EBMON a29k-none-none
6899 GDB continues to improve its handling of C++. `References' work better.
6900 The demangler has also been improved, and now deals with symbols mangled as
6901 per the Annotated C++ Reference Guide.
6903 GDB also now handles `stabs' symbol information embedded in MIPS
6904 `ecoff' symbol tables. Since the ecoff format was not easily
6905 extensible to handle new languages such as C++, this appeared to be a
6906 good way to put C++ debugging info into MIPS binaries. This option
6907 will be supported in the GNU C compiler, version 2, when it is
6910 * New features for SVR4
6912 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6913 shared libraries. Debugging dynamically linked programs should present
6914 only minor differences from debugging statically linked programs.
6916 The `info proc' command will print out information about any process
6917 on an SVR4 system (including the one you are debugging). At the moment,
6918 it prints the address mappings of the process.
6920 If you bring up GDB on another SVR4 system, please send mail to
6921 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6923 * Better dynamic linking support in SunOS
6925 Reading symbols from shared libraries which contain debugging symbols
6926 now works properly. However, there remain issues such as automatic
6927 skipping of `transfer vector' code during function calls, which
6928 make it harder to debug code in a shared library, than to debug the
6929 same code linked statically.
6933 GDB is now using the latest `getopt' routines from the FSF. This
6934 version accepts the -- prefix for options with long names. GDB will
6935 continue to accept the old forms (-option and +option) as well.
6936 Various single letter abbreviations for options have been explicity
6937 added to the option table so that they won't get overshadowed in the
6938 future by other options that begin with the same letter.
6942 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6943 Many assorted bugs have been handled. Many more remain to be handled.
6944 See the various ChangeLog files (primarily in gdb and bfd) for details.
6947 *** Changes in GDB-4.3:
6949 * New machines supported (host and target)
6951 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6952 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6953 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6955 * Almost SCO Unix support
6957 We had hoped to support:
6958 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6959 (except for core file support), but we discovered very late in the release
6960 that it has problems with process groups that render gdb unusable. Sorry
6961 about that. I encourage people to fix it and post the fixes.
6963 * Preliminary ELF and DWARF support
6965 GDB can read ELF object files on System V Release 4, and can handle
6966 debugging records for C, in DWARF format, in ELF files. This support
6967 is preliminary. If you bring up GDB on another SVR4 system, please
6968 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6973 GDB now uses the latest `readline' library. One user-visible change
6974 is that two tabs will list possible command completions, which previously
6975 required typing M-? (meta-question mark, or ESC ?).
6979 The `stepi' bug that many of you noticed has been squashed.
6980 Many bugs in C++ have been handled. Many more remain to be handled.
6981 See the various ChangeLog files (primarily in gdb and bfd) for details.
6983 * State of the MIPS world (in case you wondered):
6985 GDB can understand the symbol tables emitted by the compilers
6986 supplied by most vendors of MIPS-based machines, including DEC. These
6987 symbol tables are in a format that essentially nobody else uses.
6989 Some versions of gcc come with an assembler post-processor called
6990 mips-tfile. This program is required if you want to do source-level
6991 debugging of gcc-compiled programs. I believe FSF does not ship
6992 mips-tfile with gcc version 1, but it will eventually come with gcc
6995 Debugging of g++ output remains a problem. g++ version 1.xx does not
6996 really support it at all. (If you're lucky, you should be able to get
6997 line numbers and stack traces to work, but no parameters or local
6998 variables.) With some work it should be possible to improve the
7001 When gcc version 2 is released, you will have somewhat better luck.
7002 However, even then you will get confusing results for inheritance and
7005 We will eventually provide full debugging of g++ output on
7006 DECstations. This will probably involve some kind of stabs-in-ecoff
7007 encapulation, but the details have not been worked out yet.
7010 *** Changes in GDB-4.2:
7012 * Improved configuration
7014 Only one copy of `configure' exists now, and it is not self-modifying.
7015 Porting BFD is simpler.
7019 The `step' and `next' commands now only stop at the first instruction
7020 of a source line. This prevents the multiple stops that used to occur
7021 in switch statements, for-loops, etc. `Step' continues to stop if a
7022 function that has debugging information is called within the line.
7026 Lots of small bugs fixed. More remain.
7028 * New host supported (not target)
7030 Intel 386 PC clone running Mach i386-none-mach
7033 *** Changes in GDB-4.1:
7035 * Multiple source language support
7037 GDB now has internal scaffolding to handle several source languages.
7038 It determines the type of each source file from its filename extension,
7039 and will switch expression parsing and number formatting to match the
7040 language of the function in the currently selected stack frame.
7041 You can also specifically set the language to be used, with
7042 `set language c' or `set language modula-2'.
7046 GDB now has preliminary support for the GNU Modula-2 compiler,
7047 currently under development at the State University of New York at
7048 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7049 continue through the fall of 1991 and into 1992.
7051 Other Modula-2 compilers are currently not supported, and attempting to
7052 debug programs compiled with them will likely result in an error as the
7053 symbol table is read. Feel free to work on it, though!
7055 There are hooks in GDB for strict type checking and range checking,
7056 in the `Modula-2 philosophy', but they do not currently work.
7060 GDB can now write to executable and core files (e.g. patch
7061 a variable's value). You must turn this switch on, specify
7062 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7063 by assigning a new value to a variable. Modifications take
7066 * Automatic SunOS shared library reading
7068 When you run your program, GDB automatically determines where its
7069 shared libraries (if any) have been loaded, and reads their symbols.
7070 The `share' command is no longer needed. This also works when
7071 examining core files.
7075 You can specify the number of lines that the `list' command shows.
7078 * New machines supported (host and target)
7080 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7081 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7082 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7084 * New hosts supported (not targets)
7086 IBM RT/PC: romp-ibm-aix or rtpc
7088 * New targets supported (not hosts)
7090 AMD 29000 embedded with COFF a29k-none-coff
7091 AMD 29000 embedded with a.out a29k-none-aout
7092 Ultracomputer remote kernel debug a29k-nyu-kern
7094 * New remote interfaces
7100 *** Changes in GDB-4.0:
7104 Wide output is wrapped at good places to make the output more readable.
7106 Gdb now supports cross-debugging from a host machine of one type to a
7107 target machine of another type. Communication with the target system
7108 is over serial lines. The ``target'' command handles connecting to the
7109 remote system; the ``load'' command will download a program into the
7110 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7111 also supports debugging of realtime processes running under VxWorks,
7112 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7113 stub on the target system.
7115 New CPUs supported include the AMD 29000 and Intel 960.
7117 GDB now reads object files and symbol tables via a ``binary file''
7118 library, which allows a single copy of GDB to debug programs of multiple
7119 object file types such as a.out and coff.
7121 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7122 refcard.dvi and refcard.ps are available to format it).
7125 * Control-Variable user interface simplified
7127 All variables that control the operation of the debugger can be set
7128 by the ``set'' command, and displayed by the ``show'' command.
7130 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7131 ``Show prompt'' produces the response:
7132 Gdb's prompt is new-gdb=>.
7134 What follows are the NEW set commands. The command ``help set'' will
7135 print a complete list of old and new set commands. ``help set FOO''
7136 will give a longer description of the variable FOO. ``show'' will show
7137 all of the variable descriptions and their current settings.
7139 confirm on/off: Enables warning questions for operations that are
7140 hard to recover from, e.g. rerunning the program while
7141 it is already running. Default is ON.
7143 editing on/off: Enables EMACS style command line editing
7144 of input. Previous lines can be recalled with
7145 control-P, the current line can be edited with control-B,
7146 you can search for commands with control-R, etc.
7149 history filename NAME: NAME is where the gdb command history
7150 will be stored. The default is .gdb_history,
7151 or the value of the environment variable
7154 history size N: The size, in commands, of the command history. The
7155 default is 256, or the value of the environment variable
7158 history save on/off: If this value is set to ON, the history file will
7159 be saved after exiting gdb. If set to OFF, the
7160 file will not be saved. The default is OFF.
7162 history expansion on/off: If this value is set to ON, then csh-like
7163 history expansion will be performed on
7164 command line input. The default is OFF.
7166 radix N: Sets the default radix for input and output. It can be set
7167 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7168 in the current radix, so "set radix 10" is always a no-op.
7170 height N: This integer value is the number of lines on a page. Default
7171 is 24, the current `stty rows'' setting, or the ``li#''
7172 setting from the termcap entry matching the environment
7175 width N: This integer value is the number of characters on a line.
7176 Default is 80, the current `stty cols'' setting, or the ``co#''
7177 setting from the termcap entry matching the environment
7180 Note: ``set screensize'' is obsolete. Use ``set height'' and
7181 ``set width'' instead.
7183 print address on/off: Print memory addresses in various command displays,
7184 such as stack traces and structure values. Gdb looks
7185 more ``symbolic'' if you turn this off; it looks more
7186 ``machine level'' with it on. Default is ON.
7188 print array on/off: Prettyprint arrays. New convenient format! Default
7191 print demangle on/off: Print C++ symbols in "source" form if on,
7194 print asm-demangle on/off: Same, for assembler level printouts
7197 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7200 * Support for Epoch Environment.
7202 The epoch environment is a version of Emacs v18 with windowing. One
7203 new command, ``inspect'', is identical to ``print'', except that if you
7204 are running in the epoch environment, the value is printed in its own
7208 * Support for Shared Libraries
7210 GDB can now debug programs and core files that use SunOS shared libraries.
7211 Symbols from a shared library cannot be referenced
7212 before the shared library has been linked with the program (this
7213 happens after you type ``run'' and before the function main() is entered).
7214 At any time after this linking (including when examining core files
7215 from dynamically linked programs), gdb reads the symbols from each
7216 shared library when you type the ``sharedlibrary'' command.
7217 It can be abbreviated ``share''.
7219 sharedlibrary REGEXP: Load shared object library symbols for files
7220 matching a unix regular expression. No argument
7221 indicates to load symbols for all shared libraries.
7223 info sharedlibrary: Status of loaded shared libraries.
7228 A watchpoint stops execution of a program whenever the value of an
7229 expression changes. Checking for this slows down execution
7230 tremendously whenever you are in the scope of the expression, but is
7231 quite useful for catching tough ``bit-spreader'' or pointer misuse
7232 problems. Some machines such as the 386 have hardware for doing this
7233 more quickly, and future versions of gdb will use this hardware.
7235 watch EXP: Set a watchpoint (breakpoint) for an expression.
7237 info watchpoints: Information about your watchpoints.
7239 delete N: Deletes watchpoint number N (same as breakpoints).
7240 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7241 enable N: Re-enables watchpoint number N (same as breakpoints).
7244 * C++ multiple inheritance
7246 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7249 * C++ exception handling
7251 Gdb now supports limited C++ exception handling. Besides the existing
7252 ability to breakpoint on an exception handler, gdb can breakpoint on
7253 the raising of an exception (before the stack is peeled back to the
7256 catch FOO: If there is a FOO exception handler in the dynamic scope,
7257 set a breakpoint to catch exceptions which may be raised there.
7258 Multiple exceptions (``catch foo bar baz'') may be caught.
7260 info catch: Lists all exceptions which may be caught in the
7261 current stack frame.
7264 * Minor command changes
7266 The command ``call func (arg, arg, ...)'' now acts like the print
7267 command, except it does not print or save a value if the function's result
7268 is void. This is similar to dbx usage.
7270 The ``up'' and ``down'' commands now always print the frame they end up
7271 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7272 frames without printing.
7274 * New directory command
7276 'dir' now adds directories to the FRONT of the source search path.
7277 The path starts off empty. Source files that contain debug information
7278 about the directory in which they were compiled can be found even
7279 with an empty path; Sun CC and GCC include this information. If GDB can't
7280 find your source file in the current directory, type "dir .".
7282 * Configuring GDB for compilation
7284 For normal use, type ``./configure host''. See README or gdb.texinfo
7287 GDB now handles cross debugging. If you are remotely debugging between
7288 two different machines, type ``./configure host -target=targ''.
7289 Host is the machine where GDB will run; targ is the machine
7290 where the program that you are debugging will run.