1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * GDB now supports Thread Local Storage (TLS) variables on several
7 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
8 architectures require kernel changes. TLS is not yet supported for
9 amd64 and i386 process core dumps.
11 *** Changes in GDB 8.3
13 * GDB and GDBserver now support access to additional registers on
14 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
17 * GDB now has experimental support for the compilation and injection of
18 C++ source code into the inferior. This beta release does not include
19 support for several language features, such as templates, constructors,
22 This feature requires GCC 7.1 or higher built with libcp1.so
25 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
26 can be passed using the '[ADDRESS]:PORT' notation, or the regular
27 'ADDRESS:PORT' method.
29 * DWARF index cache: GDB can now automatically save indices of DWARF
30 symbols on disk to speed up further loading of the same binaries.
32 * Ada task switching is now supported on aarch64-elf targets when
33 debugging a program using the Ravenscar Profile. For more information,
34 see the "Tasking Support when using the Ravenscar Profile" section
35 in the GDB user manual.
37 * GDB in batch mode now exits with status 1 if the last command to be
40 * The RISC-V target now supports target descriptions.
42 * System call catchpoints now support system call aliases on FreeBSD.
43 When the ABI of a system call changes in FreeBSD, this is
44 implemented by leaving a compatibility system call using the old ABI
45 at the existing number and allocating a new system call number for
46 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
47 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
48 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
49 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
50 so that a system call catchpoint for the 'kevent' system call will
51 catch invocations of both the 'kevent' and 'freebsd11_kevent'
52 binaries. This ensures that 'kevent' system calls are caught for
53 binaries using either the old or new ABIs.
55 * Terminal styling is now available for the CLI and the TUI. GNU
56 Source Highlight can additionally be used to provide styling of
57 source code snippets. See the "set style" commands, below, for more
60 * Removed support for old demangling styles arm, edg, gnu, hp and
65 set debug compile-cplus-types
66 show debug compile-cplus-types
67 Control the display of debug output about type conversion in the
68 C++ compile feature. Commands have no effect while compiliong
73 Control whether debug output about files/functions skipping is
76 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
77 Apply a command to some frames.
78 FLAG arguments allow to control what output to produce and how to handle
79 errors raised when applying COMMAND to a frame.
82 Apply a command to all threads (ignoring errors and empty output).
83 Shortcut for 'thread apply all -s COMMAND'.
86 Apply a command to all frames (ignoring errors and empty output).
87 Shortcut for 'frame apply all -s COMMAND'.
90 Apply a command to all frames of all threads (ignoring errors and empty
92 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
94 maint set dwarf unwinders (on|off)
95 maint show dwarf unwinders
96 Control whether DWARF unwinders can be used.
99 Display a list of open files for a process.
103 Changes to the "frame", "select-frame", and "info frame" CLI commands.
104 These commands all now take a frame specification which
105 is either a frame level, or one of the keywords 'level', 'address',
106 'function', or 'view' followed by a parameter. Selecting a frame by
107 address, or viewing a frame outside the current backtrace now
108 requires the use of a keyword. Selecting a frame by level is
109 unchanged. The MI comment "-stack-select-frame" is unchanged.
111 target remote FILENAME
112 target extended-remote FILENAME
113 If FILENAME is a Unix domain socket, GDB will attempt to connect
114 to this socket instead of opening FILENAME as a character device.
116 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
117 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
118 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
119 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
120 These commands can now print only the searched entities
121 matching the provided regexp(s), giving a condition
122 on the entity names or entity types. The flag -q disables
123 printing headers or informations messages.
129 These commands now determine the syntax for the shown entities
130 according to the language chosen by `set language'. In particular,
131 `set language auto' means to automatically choose the language of
134 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
135 The 'thread apply' command accepts new FLAG arguments.
136 FLAG arguments allow to control what output to produce and how to handle
137 errors raised when applying COMMAND to a thread.
139 set tui tab-width NCHARS
140 show tui tab-width NCHARS
141 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
143 set style enabled [on|off]
145 Enable or disable terminal styling. Styling is enabled by default
146 on most hosts, but disabled by default when in batch mode.
148 set style sources [on|off]
150 Enable or disable source code styling. Source code styling is
151 enabled by default, but only takes effect if styling in general is
152 enabled, and if GDB was linked with GNU Source Highlight.
154 set style filename foreground COLOR
155 set style filename background COLOR
156 set style filename intensity VALUE
157 Control the styling of file names.
159 set style function foreground COLOR
160 set style function background COLOR
161 set style function intensity VALUE
162 Control the styling of function names.
164 set style variable foreground COLOR
165 set style variable background COLOR
166 set style variable intensity VALUE
167 Control the styling of variable names.
169 set style address foreground COLOR
170 set style address background COLOR
171 set style address intensity VALUE
172 Control the styling of addresses.
176 ** The default version of the MI interpreter is now 3 (-i=mi3).
178 ** The '-data-disassemble' MI command now accepts an '-a' option to
179 disassemble the whole function surrounding the given program
180 counter value or function name. Support for this feature can be
181 verified by using the "-list-features" command, which should
182 contain "data-disassemble-a-option".
184 ** Command responses and notifications that include a frame now include
185 the frame's architecture in a new "arch" attribute.
187 ** The output of information about multi-location breakpoints (which is
188 syntactically incorrect in MI 2) has changed in MI 3. This affects
189 the following commands and events:
193 - =breakpoint-created
194 - =breakpoint-modified
196 The -fix-multi-location-breakpoint-output command can be used to enable
197 this behavior with previous MI versions.
199 * New native configurations
201 GNU/Linux/RISC-V riscv*-*-linux*
202 FreeBSD/riscv riscv*-*-freebsd*
206 GNU/Linux/RISC-V riscv*-*-linux*
208 CSKY GNU/LINUX csky*-*-linux
209 FreeBSD/riscv riscv*-*-freebsd*
211 GNU/Linux/OpenRISC or1k*-*-linux*
215 GDB no longer supports native debugging on versions of MS-Windows
220 ** GDB no longer supports Python versions less than 2.6.
222 ** The gdb.Inferior type has a new 'progspace' property, which is the program
223 space associated to that inferior.
225 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
226 of objfiles associated to that program space.
228 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
229 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
232 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
233 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
234 correct and did not work properly.
236 ** The gdb.Value type has a new constructor, which is used to construct a
237 gdb.Value from a Python buffer object and a gdb.Type.
243 Enable or disable the undefined behavior sanitizer. This is
244 disabled by default, but passing --enable-ubsan=yes or
245 --enable-ubsan=auto to configure will enable it. Enabling this can
246 cause a performance penalty. The undefined behavior sanitizer was
247 first introduced in GCC 4.9.
249 *** Changes in GDB 8.2
251 * The 'set disassembler-options' command now supports specifying options
254 * The 'symbol-file' command now accepts an '-o' option to add a relative
255 offset to all sections.
257 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
258 a relative offset to all sections, but it allows to override the load
259 address of individual sections using '-s'.
261 * The 'add-symbol-file' command no longer requires the second argument
262 (address of the text section).
264 * The endianness used with the 'set endian auto' mode in the absence of
265 an executable selected for debugging is now the last endianness chosen
266 either by one of the 'set endian big' and 'set endian little' commands
267 or by inferring from the last executable used, rather than the startup
270 * The pager now allows a "c" response, meaning to disable the pager
271 for the rest of the current command.
273 * The commands 'info variables/functions/types' now show the source line
274 numbers of symbol definitions when available.
276 * 'info proc' now works on running processes on FreeBSD systems and core
277 files created on FreeBSD systems.
279 * C expressions can now use _Alignof, and C++ expressions can now use
282 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
283 the vector length while the process is running.
289 Control display of debugging info regarding the FreeBSD native target.
291 set|show varsize-limit
292 This new setting allows the user to control the maximum size of Ada
293 objects being printed when those objects have a variable type,
294 instead of that maximum size being hardcoded to 65536 bytes.
296 set|show record btrace cpu
297 Controls the processor to be used for enabling errata workarounds for
300 maint check libthread-db
301 Run integrity checks on the current inferior's thread debugging
304 maint set check-libthread-db (on|off)
305 maint show check-libthread-db
306 Control whether to run integrity checks on inferior specific thread
307 debugging libraries as they are loaded. The default is not to
312 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
314 ** The commands attached to a breakpoint can be set by assigning to
315 the breakpoint's "commands" field.
317 ** gdb.execute can now execute multi-line gdb commands.
319 ** The new functions gdb.convenience_variable and
320 gdb.set_convenience_variable can be used to get and set the value
321 of convenience variables.
323 ** A gdb.Parameter will no longer print the "set" help text on an
324 ordinary "set"; instead by default a "set" will be silent unless
325 the get_set_string method returns a non-empty string.
329 RiscV ELF riscv*-*-elf
331 * Removed targets and native configurations
333 m88k running OpenBSD m88*-*-openbsd*
334 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
335 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
336 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
338 * Aarch64/Linux hardware watchpoints improvements
340 Hardware watchpoints on unaligned addresses are now properly
341 supported when running Linux kernel 4.10 or higher: read and access
342 watchpoints are no longer spuriously missed, and all watchpoints
343 lengths between 1 and 8 bytes are supported. On older kernels,
344 watchpoints set on unaligned addresses are no longer missed, with
345 the tradeoff that there is a possibility of false hits being
350 --enable-codesign=CERT
351 This can be used to invoke "codesign -s CERT" after building gdb.
352 This option is useful on macOS, where code signing is required for
353 gdb to work properly.
355 --disable-gdbcli has been removed
356 This is now silently accepted, but does nothing.
358 *** Changes in GDB 8.1
360 * GDB now supports dynamically creating arbitrary register groups specified
361 in XML target descriptions. This allows for finer grain grouping of
362 registers on systems with a large amount of registers.
364 * The 'ptype' command now accepts a '/o' flag, which prints the
365 offsets and sizes of fields in a struct, like the pahole(1) tool.
367 * New "--readnever" command line option instructs GDB to not read each
368 symbol file's symbolic debug information. This makes startup faster
369 but at the expense of not being able to perform symbolic debugging.
370 This option is intended for use cases where symbolic debugging will
371 not be used, e.g., when you only need to dump the debuggee's core.
373 * GDB now uses the GNU MPFR library, if available, to emulate target
374 floating-point arithmetic during expression evaluation when the target
375 uses different floating-point formats than the host. At least version
376 3.1 of GNU MPFR is required.
378 * GDB now supports access to the guarded-storage-control registers and the
379 software-based guarded-storage broadcast control registers on IBM z14.
381 * On Unix systems, GDB now supports transmitting environment variables
382 that are to be set or unset to GDBserver. These variables will
383 affect the environment to be passed to the remote inferior.
385 To inform GDB of environment variables that are to be transmitted to
386 GDBserver, use the "set environment" command. Only user set
387 environment variables are sent to GDBserver.
389 To inform GDB of environment variables that are to be unset before
390 the remote inferior is started by the GDBserver, use the "unset
391 environment" command.
393 * Completion improvements
395 ** GDB can now complete function parameters in linespecs and
396 explicit locations without quoting. When setting breakpoints,
397 quoting around functions names to help with TAB-completion is
398 generally no longer necessary. For example, this now completes
401 (gdb) b function(in[TAB]
402 (gdb) b function(int)
404 Related, GDB is no longer confused with completing functions in
405 C++ anonymous namespaces:
408 (gdb) b (anonymous namespace)::[TAB][TAB]
409 (anonymous namespace)::a_function()
410 (anonymous namespace)::b_function()
412 ** GDB now has much improved linespec and explicit locations TAB
413 completion support, that better understands what you're
414 completing and offers better suggestions. For example, GDB no
415 longer offers data symbols as possible completions when you're
416 setting a breakpoint.
418 ** GDB now TAB-completes label symbol names.
420 ** The "complete" command now mimics TAB completion accurately.
422 * New command line options (gcore)
425 Dump all memory mappings.
427 * Breakpoints on C++ functions are now set on all scopes by default
429 By default, breakpoints on functions/methods are now interpreted as
430 specifying all functions with the given name ignoring missing
431 leading scopes (namespaces and classes).
433 For example, assuming a C++ program with symbols named:
438 both commands "break func()" and "break B::func()" set a breakpoint
441 You can use the new flag "-qualified" to override this. This makes
442 GDB interpret the specified function name as a complete
443 fully-qualified name instead. For example, using the same C++
444 program, the "break -q B::func" command sets a breakpoint on
445 "B::func", only. A parameter has been added to the Python
446 gdb.Breakpoint constructor to achieve the same result when creating
447 a breakpoint from Python.
449 * Breakpoints on functions marked with C++ ABI tags
451 GDB can now set breakpoints on functions marked with C++ ABI tags
452 (e.g., [abi:cxx11]). See here for a description of ABI tags:
453 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
455 Functions with a C++11 abi tag are demangled/displayed like this:
457 function[abi:cxx11](int)
460 You can now set a breakpoint on such functions simply as if they had
463 (gdb) b function(int)
465 Or if you need to disambiguate between tags, like:
467 (gdb) b function[abi:other_tag](int)
469 Tab completion was adjusted accordingly as well.
473 ** New events gdb.new_inferior, gdb.inferior_deleted, and
474 gdb.new_thread are emitted. See the manual for further
475 description of these.
477 ** A new function, "gdb.rbreak" has been added to the Python API.
478 This function allows the setting of a large number of breakpoints
479 via a regex pattern in Python. See the manual for further details.
481 ** Python breakpoints can now accept explicit locations. See the
482 manual for a further description of this feature.
485 * New features in the GDB remote stub, GDBserver
487 ** GDBserver is now able to start inferior processes with a
488 specified initial working directory.
490 The user can set the desired working directory to be used from
491 GDB using the new "set cwd" command.
493 ** New "--selftest" command line option runs some GDBserver self
494 tests. These self tests are disabled in releases.
496 ** On Unix systems, GDBserver now does globbing expansion and variable
497 substitution in inferior command line arguments.
499 This is done by starting inferiors using a shell, like GDB does.
500 See "set startup-with-shell" in the user manual for how to disable
501 this from GDB when using "target extended-remote". When using
502 "target remote", you can disable the startup with shell by using the
503 new "--no-startup-with-shell" GDBserver command line option.
505 ** On Unix systems, GDBserver now supports receiving environment
506 variables that are to be set or unset from GDB. These variables
507 will affect the environment to be passed to the inferior.
509 * When catching an Ada exception raised with a message, GDB now prints
510 the message in the catchpoint hit notification. In GDB/MI mode, that
511 information is provided as an extra field named "exception-message"
512 in the *stopped notification.
514 * Trait objects can now be inspected When debugging Rust code. This
515 requires compiler support which will appear in Rust 1.24.
519 QEnvironmentHexEncoded
520 Inform GDBserver of an environment variable that is to be passed to
521 the inferior when starting it.
524 Inform GDBserver of an environment variable that is to be unset
525 before starting the remote inferior.
528 Inform GDBserver that the environment should be reset (i.e.,
529 user-set environment variables should be unset).
532 Indicates whether the inferior must be started with a shell or not.
535 Tell GDBserver that the inferior to be started should use a specific
538 * The "maintenance print c-tdesc" command now takes an optional
539 argument which is the file name of XML target description.
541 * The "maintenance selftest" command now takes an optional argument to
542 filter the tests to be run.
544 * The "enable", and "disable" commands now accept a range of
545 breakpoint locations, e.g. "enable 1.3-5".
550 Set and show the current working directory for the inferior.
553 Set and show compilation command used for compiling and injecting code
554 with the 'compile' commands.
556 set debug separate-debug-file
557 show debug separate-debug-file
558 Control the display of debug output about separate debug file search.
560 set dump-excluded-mappings
561 show dump-excluded-mappings
562 Control whether mappings marked with the VM_DONTDUMP flag should be
563 dumped when generating a core file.
566 List the registered selftests.
569 Start the debugged program stopping at the first instruction.
572 Control display of debugging messages related to OpenRISC targets.
574 set|show print type nested-type-limit
575 Set and show the limit of nesting level for nested types that the
576 type printer will show.
578 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
581 * Safer/improved support for debugging with no debug info
583 GDB no longer assumes functions with no debug information return
586 This means that GDB now refuses to call such functions unless you
587 tell it the function's type, by either casting the call to the
588 declared return type, or by casting the function to a function
589 pointer of the right type, and calling that:
591 (gdb) p getenv ("PATH")
592 'getenv' has unknown return type; cast the call to its declared return type
593 (gdb) p (char *) getenv ("PATH")
594 $1 = 0x7fffffffe "/usr/local/bin:/"...
595 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
596 $2 = 0x7fffffffe "/usr/local/bin:/"...
598 Similarly, GDB no longer assumes that global variables with no debug
599 info have type 'int', and refuses to print the variable's value
600 unless you tell it the variable's type:
603 'var' has unknown type; cast it to its declared type
607 * New native configurations
609 FreeBSD/aarch64 aarch64*-*-freebsd*
610 FreeBSD/arm arm*-*-freebsd*
614 FreeBSD/aarch64 aarch64*-*-freebsd*
615 FreeBSD/arm arm*-*-freebsd*
616 OpenRISC ELF or1k*-*-elf
618 * Removed targets and native configurations
620 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
622 *** Changes in GDB 8.0
624 * GDB now supports access to the PKU register on GNU/Linux. The register is
625 added by the Memory Protection Keys for Userspace feature which will be
626 available in future Intel CPUs.
628 * GDB now supports C++11 rvalue references.
632 ** New functions to start, stop and access a running btrace recording.
633 ** Rvalue references are now supported in gdb.Type.
635 * GDB now supports recording and replaying rdrand and rdseed Intel 64
638 * Building GDB and GDBserver now requires a C++11 compiler.
640 For example, GCC 4.8 or later.
642 It is no longer possible to build GDB or GDBserver with a C
643 compiler. The --disable-build-with-cxx configure option has been
646 * Building GDB and GDBserver now requires GNU make >= 3.81.
648 It is no longer supported to build GDB or GDBserver with another
649 implementation of the make program or an earlier version of GNU make.
651 * Native debugging on MS-Windows supports command-line redirection
653 Command-line arguments used for starting programs on MS-Windows can
654 now include redirection symbols supported by native Windows shells,
655 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
656 as "run", "start", and "set args", as well as the corresponding MI
659 * Support for thread names on MS-Windows.
661 GDB now catches and handles the special exception that programs
662 running on MS-Windows use to assign names to threads in the
665 * Support for Java programs compiled with gcj has been removed.
667 * User commands now accept an unlimited number of arguments.
668 Previously, only up to 10 was accepted.
670 * The "eval" command now expands user-defined command arguments.
672 This makes it easier to process a variable number of arguments:
677 eval "print $arg%d", $i
682 * Target descriptions can now describe registers for sparc32 and sparc64.
684 * GDB now supports DWARF version 5 (debug information format).
685 Its .debug_names index is not yet supported.
687 * New native configurations
689 FreeBSD/mips mips*-*-freebsd
693 Synopsys ARC arc*-*-elf32
694 FreeBSD/mips mips*-*-freebsd
696 * Removed targets and native configurations
698 Alpha running FreeBSD alpha*-*-freebsd*
699 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
704 Erases all the flash memory regions reported by the target.
706 maint print arc arc-instruction address
707 Print internal disassembler information about instruction at a given address.
711 set disassembler-options
712 show disassembler-options
713 Controls the passing of target specific information to the disassembler.
714 If it is necessary to specify more than one disassembler option then
715 multiple options can be placed together into a comma separated list.
716 The default value is the empty string. Currently, the only supported
717 targets are ARM, PowerPC and S/390.
722 Erases all the flash memory regions reported by the target. This is
723 equivalent to the CLI command flash-erase.
725 -file-list-shared-libraries
726 List the shared libraries in the program. This is
727 equivalent to the CLI command "info shared".
730 Catchpoints stopping the program when Ada exceptions are
731 handled. This is equivalent to the CLI command "catch handlers".
733 *** Changes in GDB 7.12
735 * GDB and GDBserver now build with a C++ compiler by default.
737 The --enable-build-with-cxx configure option is now enabled by
738 default. One must now explicitly configure with
739 --disable-build-with-cxx in order to build with a C compiler. This
740 option will be removed in a future release.
742 * GDBserver now supports recording btrace without maintaining an active
745 * GDB now supports a negative repeat count in the 'x' command to examine
746 memory backward from the given address. For example:
749 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
750 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
751 (gdb) x/-5i 0x0000000000400580
752 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
753 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
754 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
755 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
756 0x40057b <main(int, char**)+25>:
757 callq 0x400536 <Func1(int, char const*)>
759 * Fortran: Support structures with fields of dynamic types and
760 arrays of dynamic types.
762 * The symbol dumping maintenance commands have new syntax.
763 maint print symbols [-pc address] [--] [filename]
764 maint print symbols [-objfile objfile] [-source source] [--] [filename]
765 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
766 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
767 maint print msymbols [-objfile objfile] [--] [filename]
769 * GDB now supports multibit bitfields and enums in target register
772 * New Python-based convenience function $_as_string(val), which returns
773 the textual representation of a value. This function is especially
774 useful to obtain the text label of an enum value.
776 * Intel MPX bound violation handling.
778 Segmentation faults caused by a Intel MPX boundary violation
779 now display the kind of violation (upper or lower), the memory
780 address accessed and the memory bounds, along with the usual
781 signal received and code location.
785 Program received signal SIGSEGV, Segmentation fault
786 Upper bound violation while accessing address 0x7fffffffc3b3
787 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
788 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
790 * Rust language support.
791 GDB now supports debugging programs written in the Rust programming
792 language. See https://www.rust-lang.org/ for more information about
795 * Support for running interpreters on specified input/output devices
797 GDB now supports a new mechanism that allows frontends to provide
798 fully featured GDB console views, as a better alternative to
799 building such views on top of the "-interpreter-exec console"
800 command. See the new "new-ui" command below. With that command,
801 frontends can now start GDB in the traditional command-line mode
802 running in an embedded terminal emulator widget, and create a
803 separate MI interpreter running on a specified i/o device. In this
804 way, GDB handles line editing, history, tab completion, etc. in the
805 console all by itself, and the GUI uses the separate MI interpreter
806 for its own control and synchronization, invisible to the command
809 * The "catch syscall" command catches groups of related syscalls.
811 The "catch syscall" command now supports catching a group of related
812 syscalls using the 'group:' or 'g:' prefix.
817 skip -gfile file-glob-pattern
818 skip -function function
819 skip -rfunction regular-expression
820 A generalized form of the skip command, with new support for
821 glob-style file names and regular expressions for function names.
822 Additionally, a file spec and a function spec may now be combined.
824 maint info line-table REGEXP
825 Display the contents of GDB's internal line table data struture.
828 Run any GDB unit tests that were compiled in.
831 Start a new user interface instance running INTERP as interpreter,
832 using the TTY file for input/output.
836 ** gdb.Breakpoint objects have a new attribute "pending", which
837 indicates whether the breakpoint is pending.
838 ** Three new breakpoint-related events have been added:
839 gdb.breakpoint_created, gdb.breakpoint_modified, and
840 gdb.breakpoint_deleted.
843 Signal ("set") the given MS-Windows event object. This is used in
844 conjunction with the Windows JIT debugging (AeDebug) support, where
845 the OS suspends a crashing process until a debugger can attach to
846 it. Resuming the crashing process, in order to debug it, is done by
849 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
850 was added in GDBserver, including JIT compiling fast tracepoint's
851 conditional expression bytecode into native code.
853 * Support for various remote target protocols and ROM monitors has
856 target m32rsdi Remote M32R debugging over SDI
857 target mips MIPS remote debugging protocol
858 target pmon PMON ROM monitor
859 target ddb NEC's DDB variant of PMON for Vr4300
860 target rockhopper NEC RockHopper variant of PMON
861 target lsi LSI variant of PMO
863 * Support for tracepoints and fast tracepoints on powerpc-linux,
864 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
865 including JIT compiling fast tracepoint's conditional expression
866 bytecode into native code.
868 * MI async record =record-started now includes the method and format used for
869 recording. For example:
871 =record-started,thread-group="i1",method="btrace",format="bts"
873 * MI async record =thread-selected now includes the frame field. For example:
875 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
879 Andes NDS32 nds32*-*-elf
881 *** Changes in GDB 7.11
883 * GDB now supports debugging kernel-based threads on FreeBSD.
885 * Per-inferior thread numbers
887 Thread numbers are now per inferior instead of global. If you're
888 debugging multiple inferiors, GDB displays thread IDs using a
889 qualified INF_NUM.THR_NUM form. For example:
893 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
894 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
895 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
896 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
898 As consequence, thread numbers as visible in the $_thread
899 convenience variable and in Python's InferiorThread.num attribute
900 are no longer unique between inferiors.
902 GDB now maintains a second thread ID per thread, referred to as the
903 global thread ID, which is the new equivalent of thread numbers in
904 previous releases. See also $_gthread below.
906 For backwards compatibility, MI's thread IDs always refer to global
909 * Commands that accept thread IDs now accept the qualified
910 INF_NUM.THR_NUM form as well. For example:
913 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
916 * In commands that accept a list of thread IDs, you can now refer to
917 all threads of an inferior using a star wildcard. GDB accepts
918 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
919 refer to all threads of the current inferior. For example, "info
922 * You can use "info threads -gid" to display the global thread ID of
925 * The new convenience variable $_gthread holds the global number of
928 * The new convenience variable $_inferior holds the number of the
931 * GDB now displays the ID and name of the thread that hit a breakpoint
932 or received a signal, if your program is multi-threaded. For
935 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
936 Thread 1 "main" received signal SIGINT, Interrupt.
938 * Record btrace now supports non-stop mode.
940 * Support for tracepoints on aarch64-linux was added in GDBserver.
942 * The 'record instruction-history' command now indicates speculative execution
943 when using the Intel Processor Trace recording format.
945 * GDB now allows users to specify explicit locations, bypassing
946 the linespec parser. This feature is also available to GDB/MI
949 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
950 GDB now is able to debug both AArch64 applications and ARM applications
953 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
954 including JIT compiling fast tracepoint's conditional expression bytecode
957 * GDB now supports displaced stepping on AArch64 GNU/Linux.
959 * "info threads", "info inferiors", "info display", "info checkpoints"
960 and "maint info program-spaces" now list the corresponding items in
961 ascending ID order, for consistency with all other "info" commands.
963 * In Ada, the overloads selection menu has been enhanced to display the
964 parameter types and the return types for the matching overloaded subprograms.
968 maint set target-non-stop (on|off|auto)
969 maint show target-non-stop
970 Control whether GDB targets always operate in non-stop mode even if
971 "set non-stop" is "off". The default is "auto", meaning non-stop
972 mode is enabled if supported by the target.
974 maint set bfd-sharing
975 maint show bfd-sharing
976 Control the reuse of bfd objects.
980 Control display of debugging info regarding bfd caching.
984 Control display of debugging info regarding FreeBSD threads.
986 set remote multiprocess-extensions-packet
987 show remote multiprocess-extensions-packet
988 Set/show the use of the remote protocol multiprocess extensions.
990 set remote thread-events
991 show remote thread-events
992 Set/show the use of thread create/exit events.
994 set ada print-signatures on|off
995 show ada print-signatures"
996 Control whether parameter types and return types are displayed in overloads
997 selection menus. It is activaled (@code{on}) by default.
1001 Controls the maximum size of memory, in bytes, that GDB will
1002 allocate for value contents. Prevents incorrect programs from
1003 causing GDB to allocate overly large buffers. Default is 64k.
1005 * The "disassemble" command accepts a new modifier: /s.
1006 It prints mixed source+disassembly like /m with two differences:
1007 - disassembled instructions are now printed in program order, and
1008 - and source for all relevant files is now printed.
1009 The "/m" option is now considered deprecated: its "source-centric"
1010 output hasn't proved useful in practice.
1012 * The "record instruction-history" command accepts a new modifier: /s.
1013 It behaves exactly like /m and prints mixed source+disassembly.
1015 * The "set scheduler-locking" command supports a new mode "replay".
1016 It behaves like "off" in record mode and like "on" in replay mode.
1018 * Support for various ROM monitors has been removed:
1020 target dbug dBUG ROM monitor for Motorola ColdFire
1021 target picobug Motorola picobug monitor
1022 target dink32 DINK32 ROM monitor for PowerPC
1023 target m32r Renesas M32R/D ROM monitor
1024 target mon2000 mon2000 ROM monitor
1025 target ppcbug PPCBUG ROM monitor for PowerPC
1027 * Support for reading/writing memory and extracting values on architectures
1028 whose memory is addressable in units of any integral multiple of 8 bits.
1031 Allows to break when an Ada exception is handled.
1033 * New remote packets
1036 Indicates that an exec system call was executed.
1038 exec-events feature in qSupported
1039 The qSupported packet allows GDB to request support for exec
1040 events using the new 'gdbfeature' exec-event, and the qSupported
1041 response can contain the corresponding 'stubfeature'. Set and
1042 show commands can be used to display whether these features are enabled.
1045 Equivalent to interrupting with the ^C character, but works in
1048 thread created stop reason (T05 create:...)
1049 Indicates that the thread was just created and is stopped at entry.
1051 thread exit stop reply (w exitcode;tid)
1052 Indicates that the thread has terminated.
1055 Enables/disables thread create and exit event reporting. For
1056 example, this is used in non-stop mode when GDB stops a set of
1057 threads and synchronously waits for the their corresponding stop
1058 replies. Without exit events, if one of the threads exits, GDB
1059 would hang forever not knowing that it should no longer expect a
1060 stop for that same thread.
1063 Indicates that there are no resumed threads left in the target (all
1064 threads are stopped). The remote stub reports support for this stop
1065 reply to GDB's qSupported query.
1068 Enables/disables catching syscalls from the inferior process.
1069 The remote stub reports support for this packet to GDB's qSupported query.
1071 syscall_entry stop reason
1072 Indicates that a syscall was just called.
1074 syscall_return stop reason
1075 Indicates that a syscall just returned.
1077 * Extended-remote exec events
1079 ** GDB now has support for exec events on extended-remote Linux targets.
1080 For such targets with Linux kernels 2.5.46 and later, this enables
1081 follow-exec-mode and exec catchpoints.
1083 set remote exec-event-feature-packet
1084 show remote exec-event-feature-packet
1085 Set/show the use of the remote exec event feature.
1087 * Thread names in remote protocol
1089 The reply to qXfer:threads:read may now include a name attribute for each
1092 * Target remote mode fork and exec events
1094 ** GDB now has support for fork and exec events on target remote mode
1095 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1096 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1097 fork and exec catchpoints.
1099 * Remote syscall events
1101 ** GDB now has support for catch syscall on remote Linux targets,
1102 currently enabled on x86/x86_64 architectures.
1104 set remote catch-syscall-packet
1105 show remote catch-syscall-packet
1106 Set/show the use of the remote catch syscall feature.
1110 ** The -var-set-format command now accepts the zero-hexadecimal
1111 format. It outputs data in hexadecimal format with zero-padding on the
1116 ** gdb.InferiorThread objects have a new attribute "global_num",
1117 which refers to the thread's global thread ID. The existing
1118 "num" attribute now refers to the thread's per-inferior number.
1119 See "Per-inferior thread numbers" above.
1120 ** gdb.InferiorThread objects have a new attribute "inferior", which
1121 is the Inferior object the thread belongs to.
1123 *** Changes in GDB 7.10
1125 * Support for process record-replay and reverse debugging on aarch64*-linux*
1126 targets has been added. GDB now supports recording of A64 instruction set
1127 including advance SIMD instructions.
1129 * Support for Sun's version of the "stabs" debug file format has been removed.
1131 * GDB now honors the content of the file /proc/PID/coredump_filter
1132 (PID is the process ID) on GNU/Linux systems. This file can be used
1133 to specify the types of memory mappings that will be included in a
1134 corefile. For more information, please refer to the manual page of
1135 "core(5)". GDB also has a new command: "set use-coredump-filter
1136 on|off". It allows to set whether GDB will read the content of the
1137 /proc/PID/coredump_filter file when generating a corefile.
1139 * The "info os" command on GNU/Linux can now display information on
1141 "info os cpus" Listing of all cpus/cores on the system
1143 * GDB has two new commands: "set serial parity odd|even|none" and
1144 "show serial parity". These allows to set or show parity for the
1147 * The "info source" command now displays the producer string if it was
1148 present in the debug info. This typically includes the compiler version
1149 and may include things like its command line arguments.
1151 * The "info dll", an alias of the "info sharedlibrary" command,
1152 is now available on all platforms.
1154 * Directory names supplied to the "set sysroot" commands may be
1155 prefixed with "target:" to tell GDB to access shared libraries from
1156 the target system, be it local or remote. This replaces the prefix
1157 "remote:". The default sysroot has been changed from "" to
1158 "target:". "remote:" is automatically converted to "target:" for
1159 backward compatibility.
1161 * The system root specified by "set sysroot" will be prepended to the
1162 filename of the main executable (if reported to GDB as absolute by
1163 the operating system) when starting processes remotely, and when
1164 attaching to already-running local or remote processes.
1166 * GDB now supports automatic location and retrieval of executable
1167 files from remote targets. Remote debugging can now be initiated
1168 using only a "target remote" or "target extended-remote" command
1169 (no "set sysroot" or "file" commands are required). See "New remote
1172 * The "dump" command now supports verilog hex format.
1174 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1176 * On GNU/Linux, GDB and gdbserver are now able to access executable
1177 and shared library files without a "set sysroot" command when
1178 attaching to processes running in different mount namespaces from
1179 the debugger. This makes it possible to attach to processes in
1180 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1181 See "New remote packets" below.
1183 * The "tui reg" command now provides completion for all of the
1184 available register groups, including target specific groups.
1186 * The HISTSIZE environment variable is no longer read when determining
1187 the size of GDB's command history. GDB now instead reads the dedicated
1188 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1189 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1194 ** Memory ports can now be unbuffered.
1198 ** gdb.Objfile objects have a new attribute "username",
1199 which is the name of the objfile as specified by the user,
1200 without, for example, resolving symlinks.
1201 ** You can now write frame unwinders in Python.
1202 ** gdb.Type objects have a new method "optimized_out",
1203 returning optimized out gdb.Value instance of this type.
1204 ** gdb.Value objects have new methods "reference_value" and
1205 "const_value" which return a reference to the value and a
1206 "const" version of the value respectively.
1210 maint print symbol-cache
1211 Print the contents of the symbol cache.
1213 maint print symbol-cache-statistics
1214 Print statistics of symbol cache usage.
1216 maint flush-symbol-cache
1217 Flush the contents of the symbol cache.
1221 Start branch trace recording using Branch Trace Store (BTS) format.
1224 Evaluate expression by using the compiler and print result.
1228 Explicit commands for enabling and disabling tui mode.
1231 set mpx bound on i386 and amd64
1232 Support for bound table investigation on Intel MPX enabled applications.
1236 Start branch trace recording using Intel Processor Trace format.
1239 Print information about branch tracing internals.
1241 maint btrace packet-history
1242 Print the raw branch tracing data.
1244 maint btrace clear-packet-history
1245 Discard the stored raw branch tracing data.
1248 Discard all branch tracing data. It will be fetched and processed
1249 anew by the next "record" command.
1254 Renamed from "set debug dwarf2-die".
1255 show debug dwarf-die
1256 Renamed from "show debug dwarf2-die".
1258 set debug dwarf-read
1259 Renamed from "set debug dwarf2-read".
1260 show debug dwarf-read
1261 Renamed from "show debug dwarf2-read".
1263 maint set dwarf always-disassemble
1264 Renamed from "maint set dwarf2 always-disassemble".
1265 maint show dwarf always-disassemble
1266 Renamed from "maint show dwarf2 always-disassemble".
1268 maint set dwarf max-cache-age
1269 Renamed from "maint set dwarf2 max-cache-age".
1270 maint show dwarf max-cache-age
1271 Renamed from "maint show dwarf2 max-cache-age".
1273 set debug dwarf-line
1274 show debug dwarf-line
1275 Control display of debugging info regarding DWARF line processing.
1278 show max-completions
1279 Set the maximum number of candidates to be considered during
1280 completion. The default value is 200. This limit allows GDB
1281 to avoid generating large completion lists, the computation of
1282 which can cause the debugger to become temporarily unresponsive.
1284 set history remove-duplicates
1285 show history remove-duplicates
1286 Control the removal of duplicate history entries.
1288 maint set symbol-cache-size
1289 maint show symbol-cache-size
1290 Control the size of the symbol cache.
1292 set|show record btrace bts buffer-size
1293 Set and show the size of the ring buffer used for branch tracing in
1295 The obtained size may differ from the requested size. Use "info
1296 record" to see the obtained buffer size.
1298 set debug linux-namespaces
1299 show debug linux-namespaces
1300 Control display of debugging info regarding Linux namespaces.
1302 set|show record btrace pt buffer-size
1303 Set and show the size of the ring buffer used for branch tracing in
1304 Intel Processor Trace format.
1305 The obtained size may differ from the requested size. Use "info
1306 record" to see the obtained buffer size.
1308 maint set|show btrace pt skip-pad
1309 Set and show whether PAD packets are skipped when computing the
1312 * The command 'thread apply all' can now support new option '-ascending'
1313 to call its specified command for all threads in ascending order.
1315 * Python/Guile scripting
1317 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1318 special section named `.debug_gdb_scripts'.
1320 * New remote packets
1322 qXfer:btrace-conf:read
1323 Return the branch trace configuration for the current thread.
1325 Qbtrace-conf:bts:size
1326 Set the requested ring buffer size for branch tracing in BTS format.
1329 Enable Intel Procesor Trace-based branch tracing for the current
1330 process. The remote stub reports support for this packet to GDB's
1333 Qbtrace-conf:pt:size
1334 Set the requested ring buffer size for branch tracing in Intel Processor
1338 Indicates a memory breakpoint instruction was executed, irrespective
1339 of whether it was GDB that planted the breakpoint or the breakpoint
1340 is hardcoded in the program. This is required for correct non-stop
1344 Indicates the target stopped for a hardware breakpoint. This is
1345 required for correct non-stop mode operation.
1348 Return information about files on the remote system.
1350 qXfer:exec-file:read
1351 Return the full absolute name of the file that was executed to
1352 create a process running on the remote system.
1355 Select the filesystem on which vFile: operations with filename
1356 arguments will operate. This is required for GDB to be able to
1357 access files on remote targets where the remote stub does not
1358 share a common filesystem with the inferior(s).
1361 Indicates that a fork system call was executed.
1364 Indicates that a vfork system call was executed.
1366 vforkdone stop reason
1367 Indicates that a vfork child of the specified process has executed
1368 an exec or exit, allowing the vfork parent to resume execution.
1370 fork-events and vfork-events features in qSupported
1371 The qSupported packet allows GDB to request support for fork and
1372 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1373 and the qSupported response can contain the corresponding
1374 'stubfeatures'. Set and show commands can be used to display
1375 whether these features are enabled.
1377 * Extended-remote fork events
1379 ** GDB now has support for fork events on extended-remote Linux
1380 targets. For targets with Linux kernels 2.5.60 and later, this
1381 enables follow-fork-mode and detach-on-fork for both fork and
1382 vfork, as well as fork and vfork catchpoints.
1384 * The info record command now shows the recording format and the
1385 branch tracing configuration for the current thread when using
1386 the btrace record target.
1387 For the BTS format, it shows the ring buffer size.
1389 * GDB now has support for DTrace USDT (Userland Static Defined
1390 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1392 * GDB now supports access to vector registers on S/390 GNU/Linux
1395 * Removed command line options
1397 -xdb HP-UX XDB compatibility mode.
1399 * Removed targets and native configurations
1401 HP/PA running HP-UX hppa*-*-hpux*
1402 Itanium running HP-UX ia64-*-hpux*
1404 * New configure options
1407 This configure option allows the user to build GDB with support for
1408 Intel Processor Trace (default: auto). This requires libipt.
1410 --with-libipt-prefix=PATH
1411 Specify the path to the version of libipt that GDB should use.
1412 $PATH/include should contain the intel-pt.h header and
1413 $PATH/lib should contain the libipt.so library.
1415 *** Changes in GDB 7.9.1
1419 ** Xmethods can now specify a result type.
1421 *** Changes in GDB 7.9
1423 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1427 ** You can now access frame registers from Python scripts.
1428 ** New attribute 'producer' for gdb.Symtab objects.
1429 ** gdb.Objfile objects have a new attribute "progspace",
1430 which is the gdb.Progspace object of the containing program space.
1431 ** gdb.Objfile objects have a new attribute "owner".
1432 ** gdb.Objfile objects have a new attribute "build_id",
1433 which is the build ID generated when the file was built.
1434 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1435 ** A new event "gdb.clear_objfiles" has been added, triggered when
1436 selecting a new file to debug.
1437 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1438 ** New function gdb.lookup_objfile.
1440 New events which are triggered when GDB modifies the state of the
1443 ** gdb.events.inferior_call_pre: Function call is about to be made.
1444 ** gdb.events.inferior_call_post: Function call has just been made.
1445 ** gdb.events.memory_changed: A memory location has been altered.
1446 ** gdb.events.register_changed: A register has been altered.
1448 * New Python-based convenience functions:
1450 ** $_caller_is(name [, number_of_frames])
1451 ** $_caller_matches(regexp [, number_of_frames])
1452 ** $_any_caller_is(name [, number_of_frames])
1453 ** $_any_caller_matches(regexp [, number_of_frames])
1455 * GDB now supports the compilation and injection of source code into
1456 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1457 to compile the source code to object code, and if successful, inject
1458 and execute that code within the current context of the inferior.
1459 Currently the C language is supported. The commands used to
1460 interface with this new feature are:
1462 compile code [-raw|-r] [--] [source code]
1463 compile file [-raw|-r] filename
1467 demangle [-l language] [--] name
1468 Demangle "name" in the specified language, or the current language
1469 if elided. This command is renamed from the "maint demangle" command.
1470 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1471 as "maint demangler-warning".
1473 queue-signal signal-name-or-number
1474 Queue a signal to be delivered to the thread when it is resumed.
1476 add-auto-load-scripts-directory directory
1477 Add entries to the list of directories from which to load auto-loaded
1480 maint print user-registers
1481 List all currently available "user" registers.
1483 compile code [-r|-raw] [--] [source code]
1484 Compile, inject, and execute in the inferior the executable object
1485 code produced by compiling the provided source code.
1487 compile file [-r|-raw] filename
1488 Compile and inject into the inferior the executable object code
1489 produced by compiling the source code stored in the filename
1492 * On resume, GDB now always passes the signal the program had stopped
1493 for to the thread the signal was sent to, even if the user changed
1494 threads before resuming. Previously GDB would often (but not
1495 always) deliver the signal to the thread that happens to be current
1498 * Conversely, the "signal" command now consistently delivers the
1499 requested signal to the current thread. GDB now asks for
1500 confirmation if the program had stopped for a signal and the user
1501 switched threads meanwhile.
1503 * "breakpoint always-inserted" modes "off" and "auto" merged.
1505 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1506 won't remove breakpoints from the target until all threads stop,
1507 even in non-stop mode. The "auto" mode has been removed, and "off"
1508 is now the default mode.
1512 set debug symbol-lookup
1513 show debug symbol-lookup
1514 Control display of debugging info regarding symbol lookup.
1518 ** The -list-thread-groups command outputs an exit-code field for
1519 inferiors that have exited.
1523 MIPS SDE mips*-sde*-elf*
1527 Support for these obsolete configurations has been removed.
1529 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1530 SGI Irix-5.x mips-*-irix5*
1531 SGI Irix-6.x mips-*-irix6*
1532 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1533 VAX running Ultrix vax-*-ultrix*
1535 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1536 and "assf"), have been removed. Use the "sharedlibrary" command, or
1537 its alias "share", instead.
1539 *** Changes in GDB 7.8
1541 * New command line options
1544 This is an alias for the --data-directory option.
1546 * GDB supports printing and modifying of variable length automatic arrays
1547 as specified in ISO C99.
1549 * The ARM simulator now supports instruction level tracing
1550 with or without disassembly.
1554 GDB now has support for scripting using Guile. Whether this is
1555 available is determined at configure time.
1556 Guile version 2.0 or greater is required.
1557 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1559 * New commands (for set/show, see "New options" below)
1563 Invoke CODE by passing it to the Guile interpreter.
1567 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1569 info auto-load guile-scripts [regexp]
1570 Print the list of automatically loaded Guile scripts.
1572 * The source command is now capable of sourcing Guile scripts.
1573 This feature is dependent on the debugger being built with Guile support.
1577 set print symbol-loading (off|brief|full)
1578 show print symbol-loading
1579 Control whether to print informational messages when loading symbol
1580 information for a file. The default is "full", but when debugging
1581 programs with large numbers of shared libraries the amount of output
1582 becomes less useful.
1584 set guile print-stack (none|message|full)
1585 show guile print-stack
1586 Show a stack trace when an error is encountered in a Guile script.
1588 set auto-load guile-scripts (on|off)
1589 show auto-load guile-scripts
1590 Control auto-loading of Guile script files.
1592 maint ada set ignore-descriptive-types (on|off)
1593 maint ada show ignore-descriptive-types
1594 Control whether the debugger should ignore descriptive types in Ada
1595 programs. The default is not to ignore the descriptive types. See
1596 the user manual for more details on descriptive types and the intended
1597 usage of this option.
1599 set auto-connect-native-target
1601 Control whether GDB is allowed to automatically connect to the
1602 native target for the run, attach, etc. commands when not connected
1603 to any target yet. See also "target native" below.
1605 set record btrace replay-memory-access (read-only|read-write)
1606 show record btrace replay-memory-access
1607 Control what memory accesses are allowed during replay.
1609 maint set target-async (on|off)
1610 maint show target-async
1611 This controls whether GDB targets operate in synchronous or
1612 asynchronous mode. Normally the default is asynchronous, if it is
1613 available; but this can be changed to more easily debug problems
1614 occurring only in synchronous mode.
1616 set mi-async (on|off)
1618 Control whether MI asynchronous mode is preferred. This supersedes
1619 "set target-async" of previous GDB versions.
1621 * "set target-async" is deprecated as a CLI option and is now an alias
1622 for "set mi-async" (only puts MI into async mode).
1624 * Background execution commands (e.g., "c&", "s&", etc.) are now
1625 possible ``out of the box'' if the target supports them. Previously
1626 the user would need to explicitly enable the possibility with the
1627 "set target-async on" command.
1629 * New features in the GDB remote stub, GDBserver
1631 ** New option --debug-format=option1[,option2,...] allows one to add
1632 additional text to each output. At present only timestamps
1633 are supported: --debug-format=timestamps.
1634 Timestamps can also be turned on with the
1635 "monitor set debug-format timestamps" command from GDB.
1637 * The 'record instruction-history' command now starts counting instructions
1638 at one. This also affects the instruction ranges reported by the
1639 'record function-call-history' command when given the /i modifier.
1641 * The command 'record function-call-history' supports a new modifier '/c' to
1642 indent the function names based on their call stack depth.
1643 The fields for the '/i' and '/l' modifier have been reordered.
1644 The source line range is now prefixed with 'at'.
1645 The instruction range is now prefixed with 'inst'.
1646 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1647 "record instruction-history" and "list" commands.
1649 * The ranges given as arguments to the 'record function-call-history' and
1650 'record instruction-history' commands are now inclusive.
1652 * The btrace record target now supports the 'record goto' command.
1653 For locations inside the execution trace, the back trace is computed
1654 based on the information stored in the execution trace.
1656 * The btrace record target supports limited reverse execution and replay.
1657 The target does not record data and therefore does not allow reading
1658 memory or registers.
1660 * The "catch syscall" command now works on s390*-linux* targets.
1662 * The "compare-sections" command is no longer specific to target
1663 remote. It now works with all targets.
1665 * All native targets are now consistently called "native".
1666 Consequently, the "target child", "target GNU", "target djgpp",
1667 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1668 commands have been replaced with "target native". The QNX/NTO port
1669 leaves the "procfs" target in place and adds a "native" target for
1670 consistency with other ports. The impact on users should be minimal
1671 as these commands previously either throwed an error, or were
1672 no-ops. The target's name is visible in the output of the following
1673 commands: "help target", "info target", "info files", "maint print
1676 * The "target native" command now connects to the native target. This
1677 can be used to launch native programs even when "set
1678 auto-connect-native-target" is set to off.
1680 * GDB now supports access to Intel MPX registers on GNU/Linux.
1682 * Support for Intel AVX-512 registers on GNU/Linux.
1683 Support displaying and modifying Intel AVX-512 registers
1684 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1686 * New remote packets
1688 qXfer:btrace:read's annex
1689 The qXfer:btrace:read packet supports a new annex 'delta' to read
1690 branch trace incrementally.
1694 ** Valid Python operations on gdb.Value objects representing
1695 structs/classes invoke the corresponding overloaded operators if
1697 ** New `Xmethods' feature in the Python API. Xmethods are
1698 additional methods or replacements for existing methods of a C++
1699 class. This feature is useful for those cases where a method
1700 defined in C++ source code could be inlined or optimized out by
1701 the compiler, making it unavailable to GDB.
1704 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1706 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1707 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1708 its alias "share", instead.
1710 * The commands "set remotebaud" and "show remotebaud" are no longer
1711 supported. Use "set serial baud" and "show serial baud" (respectively)
1716 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1717 target-async". The latter is left as a deprecated alias of the
1718 former for backward compatibility. If the target supports it,
1719 CLI background execution commands are now always possible by
1720 default, independently of whether the frontend stated a
1721 preference for asynchronous execution with "-gdb-set mi-async".
1722 Previously "-gdb-set target-async off" affected both MI execution
1723 commands and CLI execution commands.
1725 *** Changes in GDB 7.7
1727 * Improved support for process record-replay and reverse debugging on
1728 arm*-linux* targets. Support for thumb32 and syscall instruction
1729 recording has been added.
1731 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1733 * GDB now supports Fission DWP file format version 2.
1734 http://gcc.gnu.org/wiki/DebugFission
1736 * New convenience function "$_isvoid", to check whether an expression
1737 is void. A void expression is an expression where the type of the
1738 result is "void". For example, some convenience variables may be
1739 "void" when evaluated (e.g., "$_exitcode" before the execution of
1740 the program being debugged; or an undefined convenience variable).
1741 Another example, when calling a function whose return type is
1744 * The "maintenance print objfiles" command now takes an optional regexp.
1746 * The "catch syscall" command now works on arm*-linux* targets.
1748 * GDB now consistently shows "<not saved>" when printing values of
1749 registers the debug info indicates have not been saved in the frame
1750 and there's nowhere to retrieve them from
1751 (callee-saved/call-clobbered registers):
1756 (gdb) info registers rax
1759 Before, the former would print "<optimized out>", and the latter
1760 "*value not available*".
1762 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1767 ** Frame filters and frame decorators have been added.
1768 ** Temporary breakpoints are now supported.
1769 ** Line tables representation has been added.
1770 ** New attribute 'parent_type' for gdb.Field objects.
1771 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1772 ** New attribute 'name' for gdb.Type objects.
1776 Nios II ELF nios2*-*-elf
1777 Nios II GNU/Linux nios2*-*-linux
1778 Texas Instruments MSP430 msp430*-*-elf
1780 * Removed native configurations
1782 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1783 been removed. ELF variants of these configurations are kept supported.
1785 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1786 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1787 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1788 i[34567]86-*-openbsd3.[0-3]
1789 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1790 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1791 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1795 Like "catch throw", but catches a re-thrown exception.
1796 maint check-psymtabs
1797 Renamed from old "maint check-symtabs".
1799 Perform consistency checks on symtabs.
1800 maint expand-symtabs
1801 Expand symtabs matching an optional regexp.
1804 Display the details of GDB configure-time options.
1806 maint set|show per-command
1807 maint set|show per-command space
1808 maint set|show per-command time
1809 maint set|show per-command symtab
1810 Enable display of per-command gdb resource usage.
1812 remove-symbol-file FILENAME
1813 remove-symbol-file -a ADDRESS
1814 Remove a symbol file added via add-symbol-file. The file to remove
1815 can be identified by its filename or by an address that lies within
1816 the boundaries of this symbol file in memory.
1819 info exceptions REGEXP
1820 Display the list of Ada exceptions defined in the program being
1821 debugged. If provided, only the exceptions whose names match REGEXP
1826 set debug symfile off|on
1828 Control display of debugging info regarding reading symbol files and
1829 symbol tables within those files
1831 set print raw frame-arguments
1832 show print raw frame-arguments
1833 Set/show whether to print frame arguments in raw mode,
1834 disregarding any defined pretty-printers.
1836 set remote trace-status-packet
1837 show remote trace-status-packet
1838 Set/show the use of remote protocol qTStatus packet.
1842 Control display of debugging messages related to Nios II targets.
1846 Control whether target-assisted range stepping is enabled.
1848 set startup-with-shell
1849 show startup-with-shell
1850 Specifies whether Unix child processes are started via a shell or
1855 Use the target memory cache for accesses to the code segment. This
1856 improves performance of remote debugging (particularly disassembly).
1858 * You can now use a literal value 'unlimited' for options that
1859 interpret 0 or -1 as meaning "unlimited". E.g., "set
1860 trace-buffer-size unlimited" is now an alias for "set
1861 trace-buffer-size -1" and "set height unlimited" is now an alias for
1864 * The "set debug symtab-create" debugging option of GDB has been changed to
1865 accept a verbosity level. 0 means "off", 1 provides basic debugging
1866 output, and values of 2 or greater provides more verbose output.
1868 * New command-line options
1870 Display the details of GDB configure-time options.
1872 * The command 'tsave' can now support new option '-ctf' to save trace
1873 buffer in Common Trace Format.
1875 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1878 * GDB now implements the the C++ 'typeid' operator.
1880 * The new convenience variable $_exception holds the exception being
1881 thrown or caught at an exception-related catchpoint.
1883 * The exception-related catchpoints, like "catch throw", now accept a
1884 regular expression which can be used to filter exceptions by type.
1886 * The new convenience variable $_exitsignal is automatically set to
1887 the terminating signal number when the program being debugged dies
1888 due to an uncaught signal.
1892 ** All MI commands now accept an optional "--language" option.
1893 Support for this feature can be verified by using the "-list-features"
1894 command, which should contain "language-option".
1896 ** The new command -info-gdb-mi-command allows the user to determine
1897 whether a GDB/MI command is supported or not.
1899 ** The "^error" result record returned when trying to execute an undefined
1900 GDB/MI command now provides a variable named "code" whose content is the
1901 "undefined-command" error code. Support for this feature can be verified
1902 by using the "-list-features" command, which should contain
1903 "undefined-command-error-code".
1905 ** The -trace-save MI command can optionally save trace buffer in Common
1908 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1910 ** The command -data-list-register-values now accepts an optional
1911 "--skip-unavailable" option. When used, only the available registers
1914 ** The new command -trace-frame-collected dumps collected variables,
1915 computed expressions, tvars, memory and registers in a traceframe.
1917 ** The commands -stack-list-locals, -stack-list-arguments and
1918 -stack-list-variables now accept an option "--skip-unavailable".
1919 When used, only the available locals or arguments are displayed.
1921 ** The -exec-run command now accepts an optional "--start" option.
1922 When used, the command follows the same semantics as the "start"
1923 command, stopping the program's execution at the start of its
1924 main subprogram. Support for this feature can be verified using
1925 the "-list-features" command, which should contain
1926 "exec-run-start-option".
1928 ** The new commands -catch-assert and -catch-exceptions insert
1929 catchpoints stopping the program when Ada exceptions are raised.
1931 ** The new command -info-ada-exceptions provides the equivalent of
1932 the new "info exceptions" command.
1934 * New system-wide configuration scripts
1935 A GDB installation now provides scripts suitable for use as system-wide
1936 configuration scripts for the following systems:
1940 * GDB now supports target-assigned range stepping with remote targets.
1941 This improves the performance of stepping source lines by reducing
1942 the number of control packets from/to GDB. See "New remote packets"
1945 * GDB now understands the element 'tvar' in the XML traceframe info.
1946 It has the id of the collected trace state variables.
1948 * On S/390 targets that provide the transactional-execution feature,
1949 the program interruption transaction diagnostic block (TDB) is now
1950 represented as a number of additional "registers" in GDB.
1952 * New remote packets
1956 The vCont packet supports a new 'r' action, that tells the remote
1957 stub to step through an address range itself, without GDB
1958 involvemement at each single-step.
1960 qXfer:libraries-svr4:read's annex
1961 The previously unused annex of the qXfer:libraries-svr4:read packet
1962 is now used to support passing an argument list. The remote stub
1963 reports support for this argument list to GDB's qSupported query.
1964 The defined arguments are "start" and "prev", used to reduce work
1965 necessary for library list updating, resulting in significant
1968 * New features in the GDB remote stub, GDBserver
1970 ** GDBserver now supports target-assisted range stepping. Currently
1971 enabled on x86/x86_64 GNU/Linux targets.
1973 ** GDBserver now adds element 'tvar' in the XML in the reply to
1974 'qXfer:traceframe-info:read'. It has the id of the collected
1975 trace state variables.
1977 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1980 * New 'z' formatter for printing and examining memory, this displays the
1981 value as hexadecimal zero padded on the left to the size of the type.
1983 * GDB can now use Windows x64 unwinding data.
1985 * The "set remotebaud" command has been replaced by "set serial baud".
1986 Similarly, "show remotebaud" has been replaced by "show serial baud".
1987 The "set remotebaud" and "show remotebaud" commands are still available
1988 to provide backward compatibility with older versions of GDB.
1990 *** Changes in GDB 7.6
1992 * Target record has been renamed to record-full.
1993 Record/replay is now enabled with the "record full" command.
1994 This also affects settings that are associated with full record/replay
1995 that have been moved from "set/show record" to "set/show record full":
1997 set|show record full insn-number-max
1998 set|show record full stop-at-limit
1999 set|show record full memory-query
2001 * A new record target "record-btrace" has been added. The new target
2002 uses hardware support to record the control-flow of a process. It
2003 does not support replaying the execution, but it implements the
2004 below new commands for investigating the recorded execution log.
2005 This new recording method can be enabled using:
2009 The "record-btrace" target is only available on Intel Atom processors
2010 and requires a Linux kernel 2.6.32 or later.
2012 * Two new commands have been added for record/replay to give information
2013 about the recorded execution without having to replay the execution.
2014 The commands are only supported by "record btrace".
2016 record instruction-history prints the execution history at
2017 instruction granularity
2019 record function-call-history prints the execution history at
2020 function granularity
2022 * New native configurations
2024 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2025 FreeBSD/powerpc powerpc*-*-freebsd
2026 x86_64/Cygwin x86_64-*-cygwin*
2027 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2031 ARM AArch64 aarch64*-*-elf
2032 ARM AArch64 GNU/Linux aarch64*-*-linux
2033 Lynx 178 PowerPC powerpc-*-lynx*178
2034 x86_64/Cygwin x86_64-*-cygwin*
2035 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2037 * If the configured location of system.gdbinit file (as given by the
2038 --with-system-gdbinit option at configure time) is in the
2039 data-directory (as specified by --with-gdb-datadir at configure
2040 time) or in one of its subdirectories, then GDB will look for the
2041 system-wide init file in the directory specified by the
2042 --data-directory command-line option.
2044 * New command line options:
2046 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2047 other initialization files, unlike -nx which disables all of them.
2049 * Removed command line options
2051 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2054 * The 'ptype' and 'whatis' commands now accept an argument to control
2057 * 'info proc' now works on some core files.
2061 ** Vectors can be created with gdb.Type.vector.
2063 ** Python's atexit.register now works in GDB.
2065 ** Types can be pretty-printed via a Python API.
2067 ** Python 3 is now supported (in addition to Python 2.4 or later)
2069 ** New class gdb.Architecture exposes GDB's internal representation
2070 of architecture in the Python API.
2072 ** New method Frame.architecture returns the gdb.Architecture object
2073 corresponding to the frame's architecture.
2075 * New Python-based convenience functions:
2077 ** $_memeq(buf1, buf2, length)
2078 ** $_streq(str1, str2)
2080 ** $_regex(str, regex)
2082 * The 'cd' command now defaults to using '~' (the home directory) if not
2085 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2086 default for GCC since November 2000.
2088 * The command 'forward-search' can now be abbreviated as 'fo'.
2090 * The command 'info tracepoints' can now display 'installed on target'
2091 or 'not installed on target' for each non-pending location of tracepoint.
2093 * New configure options
2095 --enable-libmcheck/--disable-libmcheck
2096 By default, development versions are built with -lmcheck on hosts
2097 that support it, in order to help track memory corruption issues.
2098 Release versions, on the other hand, are built without -lmcheck
2099 by default. The --enable-libmcheck/--disable-libmcheck configure
2100 options allow the user to override that default.
2101 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2102 This configure option allows the user to build GDB with
2103 libbabeltrace using which GDB can read Common Trace Format data.
2105 * New commands (for set/show, see "New options" below)
2108 Catch signals. This is similar to "handle", but allows commands and
2109 conditions to be attached.
2112 List the BFDs known to GDB.
2114 python-interactive [command]
2116 Start a Python interactive prompt, or evaluate the optional command
2117 and print the result of expressions.
2120 "py" is a new alias for "python".
2122 enable type-printer [name]...
2123 disable type-printer [name]...
2124 Enable or disable type printers.
2128 ** For the Renesas Super-H architecture, the "regs" command has been removed
2129 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2134 set print type methods (on|off)
2135 show print type methods
2136 Control whether method declarations are displayed by "ptype".
2137 The default is to show them.
2139 set print type typedefs (on|off)
2140 show print type typedefs
2141 Control whether typedef definitions are displayed by "ptype".
2142 The default is to show them.
2144 set filename-display basename|relative|absolute
2145 show filename-display
2146 Control the way in which filenames is displayed.
2147 The default is "relative", which preserves previous behavior.
2149 set trace-buffer-size
2150 show trace-buffer-size
2151 Request target to change the size of trace buffer.
2153 set remote trace-buffer-size-packet auto|on|off
2154 show remote trace-buffer-size-packet
2155 Control the use of the remote protocol `QTBuffer:size' packet.
2159 Control display of debugging messages related to ARM AArch64.
2162 set debug coff-pe-read
2163 show debug coff-pe-read
2164 Control display of debugging messages related to reading of COFF/PE
2169 Control display of debugging messages related to Mach-O symbols
2172 set debug notification
2173 show debug notification
2174 Control display of debugging info for async remote notification.
2178 ** Command parameter changes are now notified using new async record
2179 "=cmd-param-changed".
2180 ** Trace frame changes caused by command "tfind" are now notified using
2181 new async record "=traceframe-changed".
2182 ** The creation, deletion and modification of trace state variables
2183 are now notified using new async records "=tsv-created",
2184 "=tsv-deleted" and "=tsv-modified".
2185 ** The start and stop of process record are now notified using new
2186 async record "=record-started" and "=record-stopped".
2187 ** Memory changes are now notified using new async record
2189 ** The data-disassemble command response will include a "fullname" field
2190 containing the absolute file name when source has been requested.
2191 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2192 command, to allow pattern filling of memory areas.
2193 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2194 library load/unload events.
2195 ** The response to breakpoint commands and breakpoint async records
2196 includes an "installed" field containing a boolean state about each
2197 non-pending tracepoint location is whether installed on target or not.
2198 ** Output of the "-trace-status" command includes a "trace-file" field
2199 containing the name of the trace file being examined. This field is
2200 optional, and only present when examining a trace file.
2201 ** The "fullname" field is now always present along with the "file" field,
2202 even if the file cannot be found by GDB.
2204 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2205 You must have the LZMA library available when configuring GDB for this
2206 feature to be enabled. For more information, see:
2207 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2209 * New remote packets
2212 Set the size of trace buffer. The remote stub reports support for this
2213 packet to gdb's qSupported query.
2216 Enable Branch Trace Store (BTS)-based branch tracing for the current
2217 thread. The remote stub reports support for this packet to gdb's
2221 Disable branch tracing for the current thread. The remote stub reports
2222 support for this packet to gdb's qSupported query.
2225 Read the traced branches for the current thread. The remote stub
2226 reports support for this packet to gdb's qSupported query.
2228 *** Changes in GDB 7.5
2230 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2231 for more x32 ABI info.
2233 * GDB now supports access to MIPS DSP registers on Linux targets.
2235 * GDB now supports debugging microMIPS binaries.
2237 * The "info os" command on GNU/Linux can now display information on
2238 several new classes of objects managed by the operating system:
2239 "info os procgroups" lists process groups
2240 "info os files" lists file descriptors
2241 "info os sockets" lists internet-domain sockets
2242 "info os shm" lists shared-memory regions
2243 "info os semaphores" lists semaphores
2244 "info os msg" lists message queues
2245 "info os modules" lists loaded kernel modules
2247 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2248 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2249 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2250 options and inspect the probe arguments using the new $_probe_arg family
2251 of convenience variables. You can obtain more information about SystemTap
2252 in <http://sourceware.org/systemtap/>.
2254 * GDB now supports reversible debugging on ARM, it allows you to
2255 debug basic ARM and THUMB instructions, and provides
2256 record/replay support.
2258 * The option "symbol-reloading" has been deleted as it is no longer used.
2262 ** GDB commands implemented in Python can now be put in command class
2265 ** The "maint set python print-stack on|off" is now deleted.
2267 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2268 apply "flag enum"-style pretty-printing to any enum.
2270 ** gdb.lookup_symbol can now work when there is no current frame.
2272 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2273 the source at which the symbol was defined.
2275 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2276 method 'value'. The former indicates whether the symbol needs a
2277 frame in order to compute its value, and the latter computes the
2280 ** A new method 'referenced_value' on gdb.Value objects which can
2281 dereference pointer as well as C++ reference values.
2283 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2284 which return the global and static blocks (as gdb.Block objects),
2285 of the underlying symbol table, respectively.
2287 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2288 object associated with a PC value.
2290 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2291 of the address range occupied by code for the current source line.
2293 * Go language support.
2294 GDB now supports debugging programs written in the Go programming
2297 * GDBserver now supports stdio connections.
2298 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2300 * The binary "gdbtui" can no longer be built or installed.
2301 Use "gdb -tui" instead.
2303 * GDB will now print "flag" enums specially. A flag enum is one where
2304 all the enumerator values have no bits in common when pairwise
2305 "and"ed. When printing a value whose type is a flag enum, GDB will
2306 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2307 (gdb) print (enum E) 3
2310 * The filename part of a linespec will now match trailing components
2311 of a source file name. For example, "break gcc/expr.c:1000" will
2312 now set a breakpoint in build/gcc/expr.c, but not
2313 build/libcpp/expr.c.
2315 * The "info proc" and "generate-core-file" commands will now also
2316 work on remote targets connected to GDBserver on Linux.
2318 * The command "info catch" has been removed. It has been disabled
2319 since December 2007.
2321 * The "catch exception" and "catch assert" commands now accept
2322 a condition at the end of the command, much like the "break"
2323 command does. For instance:
2325 (gdb) catch exception Constraint_Error if Barrier = True
2327 Previously, it was possible to add a condition to such catchpoints,
2328 but it had to be done as a second step, after the catchpoint had been
2329 created, using the "condition" command.
2331 * The "info static-tracepoint-marker" command will now also work on
2332 native Linux targets with in-process agent.
2334 * GDB can now set breakpoints on inlined functions.
2336 * The .gdb_index section has been updated to include symbols for
2337 inlined functions. GDB will ignore older .gdb_index sections by
2338 default, which could cause symbol files to be loaded more slowly
2339 until their .gdb_index sections can be recreated. The new command
2340 "set use-deprecated-index-sections on" will cause GDB to use any older
2341 .gdb_index sections it finds. This will restore performance, but the
2342 ability to set breakpoints on inlined functions will be lost in symbol
2343 files with older .gdb_index sections.
2345 The .gdb_index section has also been updated to record more information
2346 about each symbol. This speeds up the "info variables", "info functions"
2347 and "info types" commands when used with programs having the .gdb_index
2348 section, as well as speeding up debugging with shared libraries using
2349 the .gdb_index section.
2351 * Ada support for GDB/MI Variable Objects has been added.
2353 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2358 ** New command -info-os is the MI equivalent of "info os".
2360 ** Output logs ("set logging" and related) now include MI output.
2364 ** "set use-deprecated-index-sections on|off"
2365 "show use-deprecated-index-sections on|off"
2366 Controls the use of deprecated .gdb_index sections.
2368 ** "catch load" and "catch unload" can be used to stop when a shared
2369 library is loaded or unloaded, respectively.
2371 ** "enable count" can be used to auto-disable a breakpoint after
2374 ** "info vtbl" can be used to show the virtual method tables for
2375 C++ and Java objects.
2377 ** "explore" and its sub commands "explore value" and "explore type"
2378 can be used to recursively explore values and types of
2379 expressions. These commands are available only if GDB is
2380 configured with '--with-python'.
2382 ** "info auto-load" shows status of all kinds of auto-loaded files,
2383 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2384 sequences of commands files, "info auto-load python-scripts"
2385 shows status of auto-loading Python script files,
2386 "info auto-load local-gdbinit" shows status of loading init file
2387 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2388 status of inferior specific thread debugging shared library loading.
2390 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2391 and "show auto-load-scripts" commands have been deprecated, use their
2392 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2393 and "show auto-load python-scripts" counterparts instead.
2395 ** "dprintf location,format,args..." creates a dynamic printf, which
2396 is basically a breakpoint that does a printf and immediately
2397 resumes your program's execution, so it is like a printf that you
2398 can insert dynamically at runtime instead of at compiletime.
2400 ** "set print symbol"
2402 Controls whether GDB attempts to display the symbol, if any,
2403 corresponding to addresses it prints. This defaults to "on", but
2404 you can set it to "off" to restore GDB's previous behavior.
2406 * Deprecated commands
2408 ** For the Renesas Super-H architecture, the "regs" command has been
2409 deprecated, and "info all-registers" should be used instead.
2413 Renesas RL78 rl78-*-elf
2414 HP OpenVMS ia64 ia64-hp-openvms*
2416 * GDBserver supports evaluation of breakpoint conditions. When
2417 support is advertised by GDBserver, GDB may be told to send the
2418 breakpoint conditions in bytecode form to GDBserver. GDBserver
2419 will only report the breakpoint trigger to GDB when its condition
2424 set mips compression
2425 show mips compression
2426 Select the compressed ISA encoding used in functions that have no symbol
2427 information available. The encoding can be set to either of:
2430 and is updated automatically from ELF file flags if available.
2432 set breakpoint condition-evaluation
2433 show breakpoint condition-evaluation
2434 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2435 GDBserver ("target"). Default option "auto" chooses the most efficient
2437 This option can improve debugger efficiency depending on the speed of the
2441 Disable auto-loading globally.
2444 Show auto-loading setting of all kinds of auto-loaded files.
2446 set auto-load gdb-scripts on|off
2447 show auto-load gdb-scripts
2448 Control auto-loading of GDB canned sequences of commands files.
2450 set auto-load python-scripts on|off
2451 show auto-load python-scripts
2452 Control auto-loading of Python script files.
2454 set auto-load local-gdbinit on|off
2455 show auto-load local-gdbinit
2456 Control loading of init file (.gdbinit) from current directory.
2458 set auto-load libthread-db on|off
2459 show auto-load libthread-db
2460 Control auto-loading of inferior specific thread debugging shared library.
2462 set auto-load scripts-directory <dir1>[:<dir2>...]
2463 show auto-load scripts-directory
2464 Set a list of directories from which to load auto-loaded scripts.
2465 Automatically loaded Python scripts and GDB scripts are located in one
2466 of the directories listed by this option.
2467 The delimiter (':' above) may differ according to the host platform.
2469 set auto-load safe-path <dir1>[:<dir2>...]
2470 show auto-load safe-path
2471 Set a list of directories from which it is safe to auto-load files.
2472 The delimiter (':' above) may differ according to the host platform.
2474 set debug auto-load on|off
2475 show debug auto-load
2476 Control display of debugging info for auto-loading the files above.
2478 set dprintf-style gdb|call|agent
2480 Control the way in which a dynamic printf is performed; "gdb"
2481 requests a GDB printf command, while "call" causes dprintf to call a
2482 function in the inferior. "agent" requests that the target agent
2483 (such as GDBserver) do the printing.
2485 set dprintf-function <expr>
2486 show dprintf-function
2487 set dprintf-channel <expr>
2488 show dprintf-channel
2489 Set the function and optional first argument to the call when using
2490 the "call" style of dynamic printf.
2492 set disconnected-dprintf on|off
2493 show disconnected-dprintf
2494 Control whether agent-style dynamic printfs continue to be in effect
2495 after GDB disconnects.
2497 * New configure options
2499 --with-auto-load-dir
2500 Configure default value for the 'set auto-load scripts-directory'
2501 setting above. It defaults to '$debugdir:$datadir/auto-load',
2502 $debugdir representing global debugging info directories (available
2503 via 'show debug-file-directory') and $datadir representing GDB's data
2504 directory (available via 'show data-directory').
2506 --with-auto-load-safe-path
2507 Configure default value for the 'set auto-load safe-path' setting
2508 above. It defaults to the --with-auto-load-dir setting.
2510 --without-auto-load-safe-path
2511 Set 'set auto-load safe-path' to '/', effectively disabling this
2514 * New remote packets
2516 z0/z1 conditional breakpoints extension
2518 The z0/z1 breakpoint insertion packets have been extended to carry
2519 a list of conditional expressions over to the remote stub depending on the
2520 condition evaluation mode. The use of this extension can be controlled
2521 via the "set remote conditional-breakpoints-packet" command.
2525 Specify the signals which the remote stub may pass to the debugged
2526 program without GDB involvement.
2528 * New command line options
2530 --init-command=FILE, -ix Like --command, -x but execute it
2531 before loading inferior.
2532 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2533 execute it before loading inferior.
2535 *** Changes in GDB 7.4
2537 * GDB now handles ambiguous linespecs more consistently; the existing
2538 FILE:LINE support has been expanded to other types of linespecs. A
2539 breakpoint will now be set on all matching locations in all
2540 inferiors, and locations will be added or removed according to
2543 * GDB now allows you to skip uninteresting functions and files when
2544 stepping with the "skip function" and "skip file" commands.
2546 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2547 and "show remote hardware-watchpoint-length-limit". These allows to
2548 set or show the maximum length limit (in bytes) of a remote
2549 target hardware watchpoint.
2551 This allows e.g. to use "unlimited" hardware watchpoints with the
2552 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2553 watchpoints are slower than real hardware watchpoints but are
2554 significantly faster than gdb software watchpoints.
2558 ** The register_pretty_printer function in module gdb.printing now takes
2559 an optional `replace' argument. If True, the new printer replaces any
2562 ** The "maint set python print-stack on|off" command has been
2563 deprecated and will be deleted in GDB 7.5.
2564 A new command: "set python print-stack none|full|message" has
2565 replaced it. Additionally, the default for "print-stack" is
2566 now "message", which just prints the error message without
2569 ** A prompt substitution hook (prompt_hook) is now available to the
2572 ** A new Python module, gdb.prompt has been added to the GDB Python
2573 modules library. This module provides functionality for
2574 escape sequences in prompts (used by set/show
2575 extended-prompt). These escape sequences are replaced by their
2576 corresponding value.
2578 ** Python commands and convenience-functions located in
2579 'data-directory'/python/gdb/command and
2580 'data-directory'/python/gdb/function are now automatically loaded
2583 ** Blocks now provide four new attributes. global_block and
2584 static_block will return the global and static blocks
2585 respectively. is_static and is_global are boolean attributes
2586 that indicate if the block is one of those two types.
2588 ** Symbols now provide the "type" attribute, the type of the symbol.
2590 ** The "gdb.breakpoint" function has been deprecated in favor of
2593 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2594 of a function. This class is based on the "finish" command
2595 available in the CLI.
2597 ** Type objects for struct and union types now allow access to
2598 the fields using standard Python dictionary (mapping) methods.
2599 For example, "some_type['myfield']" now works, as does
2600 "some_type.items()".
2602 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2605 ** A new function, "deep_items" has been added to the gdb.types
2606 module in the GDB Python modules library. This function returns
2607 an iterator over the fields of a struct or union type. Unlike
2608 the standard Python "iteritems" method, it will recursively traverse
2609 any anonymous fields.
2613 ** "*stopped" events can report several new "reason"s, such as
2616 ** Breakpoint changes are now notified using new async records, like
2617 "=breakpoint-modified".
2619 ** New command -ada-task-info.
2621 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2622 $sdir specifies the default system locations of shared libraries.
2623 $pdir specifies the directory where the libpthread used by the application
2626 GDB no longer looks in $sdir and $pdir after it has searched the directories
2627 mentioned in libthread-db-search-path. If you want to search those
2628 directories, they must be specified in libthread-db-search-path.
2629 The default value of libthread-db-search-path on GNU/Linux and Solaris
2630 systems is now "$sdir:$pdir".
2632 $pdir is not supported by gdbserver, it is currently ignored.
2633 $sdir is supported by gdbserver.
2635 * New configure option --with-iconv-bin.
2636 When using the internationalization support like the one in the GNU C
2637 library, GDB will invoke the "iconv" program to get a list of supported
2638 character sets. If this program lives in a non-standard location, one can
2639 use this option to specify where to find it.
2641 * When natively debugging programs on PowerPC BookE processors running
2642 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2643 watchpoints, which specify a mask in addition to an address to watch.
2644 The mask specifies that some bits of an address (the bits which are
2645 reset in the mask) should be ignored when matching the address accessed
2646 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2647 section in the user manual for more details.
2649 * The new option --once causes GDBserver to stop listening for connections once
2650 the first connection is made. The listening port used by GDBserver will
2651 become available after that.
2653 * New commands "info macros" and "alias" have been added.
2655 * New function parameters suffix @entry specifies value of function parameter
2656 at the time the function got called. Entry values are available only since
2662 "!" is now an alias of the "shell" command.
2663 Note that no space is needed between "!" and SHELL COMMAND.
2667 watch EXPRESSION mask MASK_VALUE
2668 The watch command now supports the mask argument which allows creation
2669 of masked watchpoints, if the current architecture supports this feature.
2671 info auto-load-scripts [REGEXP]
2672 This command was formerly named "maintenance print section-scripts".
2673 It is now generally useful and is no longer a maintenance-only command.
2675 info macro [-all] [--] MACRO
2676 The info macro command has new options `-all' and `--'. The first for
2677 printing all definitions of a macro. The second for explicitly specifying
2678 the end of arguments and the beginning of the macro name in case the macro
2679 name starts with a hyphen.
2681 collect[/s] EXPRESSIONS
2682 The tracepoint collect command now takes an optional modifier "/s"
2683 that directs it to dereference pointer-to-character types and
2684 collect the bytes of memory up to a zero byte. The behavior is
2685 similar to what you see when you use the regular print command on a
2686 string. An optional integer following the "/s" sets a bound on the
2687 number of bytes that will be collected.
2690 The trace start command now interprets any supplied arguments as a
2691 note to be recorded with the trace run, with an effect similar to
2692 setting the variable trace-notes.
2695 The trace stop command now interprets any arguments as a note to be
2696 mentioned along with the tstatus report that the trace was stopped
2697 with a command. The effect is similar to setting the variable
2700 * Tracepoints can now be enabled and disabled at any time after a trace
2701 experiment has been started using the standard "enable" and "disable"
2702 commands. It is now possible to start a trace experiment with no enabled
2703 tracepoints; GDB will display a warning, but will allow the experiment to
2704 begin, assuming that tracepoints will be enabled as needed while the trace
2707 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2708 locations with 4-byte instructions, when they were previously
2709 limited to locations with instructions of 5 bytes or longer.
2713 set debug dwarf2-read
2714 show debug dwarf2-read
2715 Turns on or off display of debugging messages related to reading
2716 DWARF debug info. The default is off.
2718 set debug symtab-create
2719 show debug symtab-create
2720 Turns on or off display of debugging messages related to symbol table
2721 creation. The default is off.
2724 show extended-prompt
2725 Set the GDB prompt, and allow escape sequences to be inserted to
2726 display miscellaneous information (see 'help set extended-prompt'
2727 for the list of sequences). This prompt (and any information
2728 accessed through the escape sequences) is updated every time the
2729 prompt is displayed.
2731 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2732 show print entry-values
2733 Set printing of frame argument values at function entry. In some cases
2734 GDB can determine the value of function argument which was passed by the
2735 function caller, even if the value was modified inside the called function.
2737 set debug entry-values
2738 show debug entry-values
2739 Control display of debugging info for determining frame argument values at
2740 function entry and virtual tail call frames.
2742 set basenames-may-differ
2743 show basenames-may-differ
2744 Set whether a source file may have multiple base names.
2745 (A "base name" is the name of a file with the directory part removed.
2746 Example: The base name of "/home/user/hello.c" is "hello.c".)
2747 If set, GDB will canonicalize file names (e.g., expand symlinks)
2748 before comparing them. Canonicalization is an expensive operation,
2749 but it allows the same file be known by more than one base name.
2750 If not set (the default), all source files are assumed to have just
2751 one base name, and gdb will do file name comparisons more efficiently.
2757 Set a user name and notes for the current and any future trace runs.
2758 This is useful for long-running and/or disconnected traces, to
2759 inform others (or yourself) as to who is running the trace, supply
2760 contact information, or otherwise explain what is going on.
2762 set trace-stop-notes
2763 show trace-stop-notes
2764 Set a note attached to the trace run, that is displayed when the
2765 trace has been stopped by a tstop command. This is useful for
2766 instance as an explanation, if you are stopping a trace run that was
2767 started by someone else.
2769 * New remote packets
2773 Dynamically enable a tracepoint in a started trace experiment.
2777 Dynamically disable a tracepoint in a started trace experiment.
2781 Set the user and notes of the trace run.
2785 Query the current status of a tracepoint.
2789 Query the minimum length of instruction at which a fast tracepoint may
2792 * Dcache size (number of lines) and line-size are now runtime-configurable
2793 via "set dcache line" and "set dcache line-size" commands.
2797 Texas Instruments TMS320C6x tic6x-*-*
2801 Renesas RL78 rl78-*-elf
2803 *** Changes in GDB 7.3.1
2805 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2807 *** Changes in GDB 7.3
2809 * GDB has a new command: "thread find [REGEXP]".
2810 It finds the thread id whose name, target id, or thread extra info
2811 matches the given regular expression.
2813 * The "catch syscall" command now works on mips*-linux* targets.
2815 * The -data-disassemble MI command now supports modes 2 and 3 for
2816 dumping the instruction opcodes.
2818 * New command line options
2820 -data-directory DIR Specify DIR as the "data-directory".
2821 This is mostly for testing purposes.
2823 * The "maint set python auto-load on|off" command has been renamed to
2824 "set auto-load-scripts on|off".
2826 * GDB has a new command: "set directories".
2827 It is like the "dir" command except that it replaces the
2828 source path list instead of augmenting it.
2830 * GDB now understands thread names.
2832 On GNU/Linux, "info threads" will display the thread name as set by
2833 prctl or pthread_setname_np.
2835 There is also a new command, "thread name", which can be used to
2836 assign a name internally for GDB to display.
2839 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2840 has been integrated into GDB.
2844 ** The function gdb.Write now accepts an optional keyword 'stream'.
2845 This keyword, when provided, will direct the output to either
2846 stdout, stderr, or GDB's logging output.
2848 ** Parameters can now be be sub-classed in Python, and in particular
2849 you may implement the get_set_doc and get_show_doc functions.
2850 This improves how Parameter set/show documentation is processed
2851 and allows for more dynamic content.
2853 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2854 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2855 have an is_valid method.
2857 ** Breakpoints can now be sub-classed in Python, and in particular
2858 you may implement a 'stop' function that is executed each time
2859 the inferior reaches that breakpoint.
2861 ** New function gdb.lookup_global_symbol looks up a global symbol.
2863 ** GDB values in Python are now callable if the value represents a
2864 function. For example, if 'some_value' represents a function that
2865 takes two integer parameters and returns a value, you can call
2866 that function like so:
2868 result = some_value (10,20)
2870 ** Module gdb.types has been added.
2871 It contains a collection of utilities for working with gdb.Types objects:
2872 get_basic_type, has_field, make_enum_dict.
2874 ** Module gdb.printing has been added.
2875 It contains utilities for writing and registering pretty-printers.
2876 New classes: PrettyPrinter, SubPrettyPrinter,
2877 RegexpCollectionPrettyPrinter.
2878 New function: register_pretty_printer.
2880 ** New commands "info pretty-printers", "enable pretty-printer" and
2881 "disable pretty-printer" have been added.
2883 ** gdb.parameter("directories") is now available.
2885 ** New function gdb.newest_frame returns the newest frame in the
2888 ** The gdb.InferiorThread class has a new "name" attribute. This
2889 holds the thread's name.
2891 ** Python Support for Inferior events.
2892 Python scripts can add observers to be notified of events
2893 occurring in the process being debugged.
2894 The following events are currently supported:
2895 - gdb.events.cont Continue event.
2896 - gdb.events.exited Inferior exited event.
2897 - gdb.events.stop Signal received, and Breakpoint hit events.
2901 ** GDB now puts template parameters in scope when debugging in an
2902 instantiation. For example, if you have:
2904 template<int X> int func (void) { return X; }
2906 then if you step into func<5>, "print X" will show "5". This
2907 feature requires proper debuginfo support from the compiler; it
2908 was added to GCC 4.5.
2910 ** The motion commands "next", "finish", "until", and "advance" now
2911 work better when exceptions are thrown. In particular, GDB will
2912 no longer lose control of the inferior; instead, the GDB will
2913 stop the inferior at the point at which the exception is caught.
2914 This functionality requires a change in the exception handling
2915 code that was introduced in GCC 4.5.
2917 * GDB now follows GCC's rules on accessing volatile objects when
2918 reading or writing target state during expression evaluation.
2919 One notable difference to prior behavior is that "print x = 0"
2920 no longer generates a read of x; the value of the assignment is
2921 now always taken directly from the value being assigned.
2923 * GDB now has some support for using labels in the program's source in
2924 linespecs. For instance, you can use "advance label" to continue
2925 execution to a label.
2927 * GDB now has support for reading and writing a new .gdb_index
2928 section. This section holds a fast index of DWARF debugging
2929 information and can be used to greatly speed up GDB startup and
2930 operation. See the documentation for `save gdb-index' for details.
2932 * The "watch" command now accepts an optional "-location" argument.
2933 When used, this causes GDB to watch the memory referred to by the
2934 expression. Such a watchpoint is never deleted due to it going out
2937 * GDB now supports thread debugging of core dumps on GNU/Linux.
2939 GDB now activates thread debugging using the libthread_db library
2940 when debugging GNU/Linux core dumps, similarly to when debugging
2941 live processes. As a result, when debugging a core dump file, GDB
2942 is now able to display pthread_t ids of threads. For example, "info
2943 threads" shows the same output as when debugging the process when it
2944 was live. In earlier releases, you'd see something like this:
2947 * 1 LWP 6780 main () at main.c:10
2949 While now you see this:
2952 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2954 It is also now possible to inspect TLS variables when debugging core
2957 When debugging a core dump generated on a machine other than the one
2958 used to run GDB, you may need to point GDB at the correct
2959 libthread_db library with the "set libthread-db-search-path"
2960 command. See the user manual for more details on this command.
2962 * When natively debugging programs on PowerPC BookE processors running
2963 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2964 which stop execution of the inferior whenever it executes an instruction
2965 at any address within the specified range. See the "PowerPC Embedded"
2966 section in the user manual for more details.
2968 * New features in the GDB remote stub, GDBserver
2970 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2971 and i686 LynxOS (version 5.x).
2973 ** GDBserver is now supported on Blackfin Linux.
2975 * New native configurations
2977 ia64 HP-UX ia64-*-hpux*
2981 Analog Devices, Inc. Blackfin Processor bfin-*
2983 * Ada task switching is now supported on sparc-elf targets when
2984 debugging a program using the Ravenscar Profile. For more information,
2985 see the "Tasking Support when using the Ravenscar Profile" section
2986 in the GDB user manual.
2988 * Guile support was removed.
2990 * New features in the GNU simulator
2992 ** The --map-info flag lists all known core mappings.
2994 ** CFI flashes may be simulated via the "cfi" device.
2996 *** Changes in GDB 7.2
2998 * Shared library support for remote targets by default
3000 When GDB is configured for a generic, non-OS specific target, like
3001 for example, --target=arm-eabi or one of the many *-*-elf targets,
3002 GDB now queries remote stubs for loaded shared libraries using the
3003 `qXfer:libraries:read' packet. Previously, shared library support
3004 was always disabled for such configurations.
3008 ** Argument Dependent Lookup (ADL)
3010 In C++ ADL lookup directs function search to the namespaces of its
3011 arguments even if the namespace has not been imported.
3021 Here the compiler will search for `foo' in the namespace of 'b'
3022 and find A::foo. GDB now supports this. This construct is commonly
3023 used in the Standard Template Library for operators.
3025 ** Improved User Defined Operator Support
3027 In addition to member operators, GDB now supports lookup of operators
3028 defined in a namespace and imported with a `using' directive, operators
3029 defined in the global scope, operators imported implicitly from an
3030 anonymous namespace, and the ADL operators mentioned in the previous
3032 GDB now also supports proper overload resolution for all the previously
3033 mentioned flavors of operators.
3035 ** static const class members
3037 Printing of static const class members that are initialized in the
3038 class definition has been fixed.
3040 * Windows Thread Information Block access.
3042 On Windows targets, GDB now supports displaying the Windows Thread
3043 Information Block (TIB) structure. This structure is visible either
3044 by using the new command `info w32 thread-information-block' or, by
3045 dereferencing the new convenience variable named `$_tlb', a
3046 thread-specific pointer to the TIB. This feature is also supported
3047 when remote debugging using GDBserver.
3049 * Static tracepoints
3051 Static tracepoints are calls in the user program into a tracing
3052 library. One such library is a port of the LTTng kernel tracer to
3053 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3054 When debugging with GDBserver, GDB now supports combining the GDB
3055 tracepoint machinery with such libraries. For example: the user can
3056 use GDB to probe a static tracepoint marker (a call from the user
3057 program into the tracing library) with the new "strace" command (see
3058 "New commands" below). This creates a "static tracepoint" in the
3059 breakpoint list, that can be manipulated with the same feature set
3060 as fast and regular tracepoints. E.g., collect registers, local and
3061 global variables, collect trace state variables, and define
3062 tracepoint conditions. In addition, the user can collect extra
3063 static tracepoint marker specific data, by collecting the new
3064 $_sdata internal variable. When analyzing the trace buffer, you can
3065 inspect $_sdata like any other variable available to GDB. For more
3066 information, see the "Tracepoints" chapter in GDB user manual. New
3067 remote packets have been defined to support static tracepoints, see
3068 the "New remote packets" section below.
3070 * Better reconstruction of tracepoints after disconnected tracing
3072 GDB will attempt to download the original source form of tracepoint
3073 definitions when starting a trace run, and then will upload these
3074 upon reconnection to the target, resulting in a more accurate
3075 reconstruction of the tracepoints that are in use on the target.
3079 You can now exercise direct control over the ways that GDB can
3080 affect your program. For instance, you can disallow the setting of
3081 breakpoints, so that the program can run continuously (assuming
3082 non-stop mode). In addition, the "observer" variable is available
3083 to switch all of the different controls; in observer mode, GDB
3084 cannot affect the target's behavior at all, which is useful for
3085 tasks like diagnosing live systems in the field.
3087 * The new convenience variable $_thread holds the number of the
3090 * New remote packets
3094 Return the address of the Windows Thread Information Block of a given thread.
3098 In response to several of the tracepoint packets, the target may now
3099 also respond with a number of intermediate `qRelocInsn' request
3100 packets before the final result packet, to have GDB handle
3101 relocating an instruction to execute at a different address. This
3102 is particularly useful for stubs that support fast tracepoints. GDB
3103 reports support for this feature in the qSupported packet.
3107 List static tracepoint markers in the target program.
3111 List static tracepoint markers at a given address in the target
3114 qXfer:statictrace:read
3116 Read the static trace data collected (by a `collect $_sdata'
3117 tracepoint action). The remote stub reports support for this packet
3118 to gdb's qSupported query.
3122 Send the current settings of GDB's permission flags.
3126 Send part of the source (textual) form of a tracepoint definition,
3127 which includes location, conditional, and action list.
3129 * The source command now accepts a -s option to force searching for the
3130 script in the source search path even if the script name specifies
3133 * New features in the GDB remote stub, GDBserver
3135 - GDBserver now support tracepoints (including fast tracepoints, and
3136 static tracepoints). The feature is currently supported by the
3137 i386-linux and amd64-linux builds. See the "Tracepoints support
3138 in gdbserver" section in the manual for more information.
3140 GDBserver JIT compiles the tracepoint's conditional agent
3141 expression bytecode into native code whenever possible for low
3142 overhead dynamic tracepoints conditionals. For such tracepoints,
3143 an expression that examines program state is evaluated when the
3144 tracepoint is reached, in order to determine whether to capture
3145 trace data. If the condition is simple and false, processing the
3146 tracepoint finishes very quickly and no data is gathered.
3148 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3149 for static tracepoints support.
3151 - GDBserver now supports x86_64 Windows 64-bit debugging.
3153 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3154 it understands register description.
3156 * The --batch flag now disables pagination and queries.
3158 * X86 general purpose registers
3160 GDB now supports reading/writing byte, word and double-word x86
3161 general purpose registers directly. This means you can use, say,
3162 $ah or $ax to refer, respectively, to the byte register AH and
3163 16-bit word register AX that are actually portions of the 32-bit
3164 register EAX or 64-bit register RAX.
3166 * The `commands' command now accepts a range of breakpoints to modify.
3167 A plain `commands' following a command that creates multiple
3168 breakpoints affects all the breakpoints set by that command. This
3169 applies to breakpoints set by `rbreak', and also applies when a
3170 single `break' command creates multiple breakpoints (e.g.,
3171 breakpoints on overloaded c++ functions).
3173 * The `rbreak' command now accepts a filename specification as part of
3174 its argument, limiting the functions selected by the regex to those
3175 in the specified file.
3177 * Support for remote debugging Windows and SymbianOS shared libraries
3178 from Unix hosts has been improved. Non Windows GDB builds now can
3179 understand target reported file names that follow MS-DOS based file
3180 system semantics, such as file names that include drive letters and
3181 use the backslash character as directory separator. This makes it
3182 possible to transparently use the "set sysroot" and "set
3183 solib-search-path" on Unix hosts to point as host copies of the
3184 target's shared libraries. See the new command "set
3185 target-file-system-kind" described below, and the "Commands to
3186 specify files" section in the user manual for more information.
3190 eval template, expressions...
3191 Convert the values of one or more expressions under the control
3192 of the string template to a command line, and call it.
3194 set target-file-system-kind unix|dos-based|auto
3195 show target-file-system-kind
3196 Set or show the assumed file system kind for target reported file
3199 save breakpoints <filename>
3200 Save all current breakpoint definitions to a file suitable for use
3201 in a later debugging session. To read the saved breakpoint
3202 definitions, use the `source' command.
3204 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3207 info static-tracepoint-markers
3208 Display information about static tracepoint markers in the target.
3210 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3211 Define a static tracepoint by probing a marker at the given
3212 function, line, address, or marker ID.
3216 Enable and disable observer mode.
3218 set may-write-registers on|off
3219 set may-write-memory on|off
3220 set may-insert-breakpoints on|off
3221 set may-insert-tracepoints on|off
3222 set may-insert-fast-tracepoints on|off
3223 set may-interrupt on|off
3224 Set individual permissions for GDB effects on the target. Note that
3225 some of these settings can have undesirable or surprising
3226 consequences, particularly when changed in the middle of a session.
3227 For instance, disabling the writing of memory can prevent
3228 breakpoints from being inserted, cause single-stepping to fail, or
3229 even crash your program, if you disable after breakpoints have been
3230 inserted. However, GDB should not crash.
3232 set record memory-query on|off
3233 show record memory-query
3234 Control whether to stop the inferior if memory changes caused
3235 by an instruction cannot be recorded.
3240 The disassemble command now supports "start,+length" form of two arguments.
3244 ** GDB now provides a new directory location, called the python directory,
3245 where Python scripts written for GDB can be installed. The location
3246 of that directory is <data-directory>/python, where <data-directory>
3247 is the GDB data directory. For more details, see section `Scripting
3248 GDB using Python' in the manual.
3250 ** The GDB Python API now has access to breakpoints, symbols, symbol
3251 tables, program spaces, inferiors, threads and frame's code blocks.
3252 Additionally, GDB Parameters can now be created from the API, and
3253 manipulated via set/show in the CLI.
3255 ** New functions gdb.target_charset, gdb.target_wide_charset,
3256 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3258 ** New exception gdb.GdbError.
3260 ** Pretty-printers are now also looked up in the current program space.
3262 ** Pretty-printers can now be individually enabled and disabled.
3264 ** GDB now looks for names of Python scripts to auto-load in a
3265 special section named `.debug_gdb_scripts', in addition to looking
3266 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3268 * Tracepoint actions were unified with breakpoint commands. In particular,
3269 there are no longer differences in "info break" output for breakpoints and
3270 tracepoints and the "commands" command can be used for both tracepoints and
3271 regular breakpoints.
3275 ARM Symbian arm*-*-symbianelf*
3277 * D language support.
3278 GDB now supports debugging programs written in the D programming
3281 * GDB now supports the extended ptrace interface for PowerPC which is
3282 available since Linux kernel version 2.6.34. This automatically enables
3283 any hardware breakpoints and additional hardware watchpoints available in
3284 the processor. The old ptrace interface exposes just one hardware
3285 watchpoint and no hardware breakpoints.
3287 * GDB is now able to use the Data Value Compare (DVC) register available on
3288 embedded PowerPC processors to implement in hardware simple watchpoint
3289 conditions of the form:
3291 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3293 This works in native GDB running on Linux kernels with the extended ptrace
3294 interface mentioned above.
3296 *** Changes in GDB 7.1
3300 ** Namespace Support
3302 GDB now supports importing of namespaces in C++. This enables the
3303 user to inspect variables from imported namespaces. Support for
3304 namepace aliasing has also been added. So, if a namespace is
3305 aliased in the current scope (e.g. namepace C=A; ) the user can
3306 print variables using the alias (e.g. (gdb) print C::x).
3310 All known bugs relating to the printing of virtual base class were
3311 fixed. It is now possible to call overloaded static methods using a
3316 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3317 and reinterpret_cast<> are now handled by the C++ expression parser.
3321 Xilinx MicroBlaze microblaze-*-*
3326 Xilinx MicroBlaze microblaze
3329 * Multi-program debugging.
3331 GDB now has support for multi-program (a.k.a. multi-executable or
3332 multi-exec) debugging. This allows for debugging multiple inferiors
3333 simultaneously each running a different program under the same GDB
3334 session. See "Debugging Multiple Inferiors and Programs" in the
3335 manual for more information. This implied some user visible changes
3336 in the multi-inferior support. For example, "info inferiors" now
3337 lists inferiors that are not running yet or that have exited
3338 already. See also "New commands" and "New options" below.
3340 * New tracing features
3342 GDB's tracepoint facility now includes several new features:
3344 ** Trace state variables
3346 GDB tracepoints now include support for trace state variables, which
3347 are variables managed by the target agent during a tracing
3348 experiment. They are useful for tracepoints that trigger each
3349 other, so for instance one tracepoint can count hits in a variable,
3350 and then a second tracepoint has a condition that is true when the
3351 count reaches a particular value. Trace state variables share the
3352 $-syntax of GDB convenience variables, and can appear in both
3353 tracepoint actions and condition expressions. Use the "tvariable"
3354 command to create, and "info tvariables" to view; see "Trace State
3355 Variables" in the manual for more detail.
3359 GDB now includes an option for defining fast tracepoints, which
3360 targets may implement more efficiently, such as by installing a jump
3361 into the target agent rather than a trap instruction. The resulting
3362 speedup can be by two orders of magnitude or more, although the
3363 tradeoff is that some program locations on some target architectures
3364 might not allow fast tracepoint installation, for instance if the
3365 instruction to be replaced is shorter than the jump. To request a
3366 fast tracepoint, use the "ftrace" command, with syntax identical to
3367 the regular trace command.
3369 ** Disconnected tracing
3371 It is now possible to detach GDB from the target while it is running
3372 a trace experiment, then reconnect later to see how the experiment
3373 is going. In addition, a new variable disconnected-tracing lets you
3374 tell the target agent whether to continue running a trace if the
3375 connection is lost unexpectedly.
3379 GDB now has the ability to save the trace buffer into a file, and
3380 then use that file as a target, similarly to you can do with
3381 corefiles. You can select trace frames, print data that was
3382 collected in them, and use tstatus to display the state of the
3383 tracing run at the moment that it was saved. To create a trace
3384 file, use "tsave <filename>", and to use it, do "target tfile
3387 ** Circular trace buffer
3389 You can ask the target agent to handle the trace buffer as a
3390 circular buffer, discarding the oldest trace frames to make room for
3391 newer ones, by setting circular-trace-buffer to on. This feature may
3392 not be available for all target agents.
3397 The disassemble command, when invoked with two arguments, now requires
3398 the arguments to be comma-separated.
3401 The info variables command now displays variable definitions. Files
3402 which only declare a variable are not shown.
3405 The source command is now capable of sourcing Python scripts.
3406 This feature is dependent on the debugger being build with Python
3409 Related to this enhancement is also the introduction of a new command
3410 "set script-extension" (see below).
3412 * New commands (for set/show, see "New options" below)
3414 record save [<FILENAME>]
3415 Save a file (in core file format) containing the process record
3416 execution log for replay debugging at a later time.
3418 record restore <FILENAME>
3419 Restore the process record execution log that was saved at an
3420 earlier time, for replay debugging.
3422 add-inferior [-copies <N>] [-exec <FILENAME>]
3425 clone-inferior [-copies <N>] [ID]
3426 Make a new inferior ready to execute the same program another
3427 inferior has loaded.
3432 maint info program-spaces
3433 List the program spaces loaded into GDB.
3435 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3436 show remote interrupt-sequence
3437 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3438 as the sequence to the remote target in order to interrupt the execution.
3439 Ctrl-C is a default. Some system prefers BREAK which is high level of
3440 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3441 Magic SysRq g. It is BREAK signal and character 'g'.
3443 set remote interrupt-on-connect [on | off]
3444 show remote interrupt-on-connect
3445 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3446 remote target when gdb connects to it. This is needed when you debug
3449 set remotebreak [on | off]
3451 Deprecated. Use "set/show remote interrupt-sequence" instead.
3453 tvariable $NAME [ = EXP ]
3454 Create or modify a trace state variable.
3457 List trace state variables and their values.
3459 delete tvariable $NAME ...
3460 Delete one or more trace state variables.
3463 Evaluate the given expressions without collecting anything into the
3464 trace buffer. (Valid in tracepoint actions only.)
3466 ftrace FN / FILE:LINE / *ADDR
3467 Define a fast tracepoint at the given function, line, or address.
3469 * New expression syntax
3471 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3472 GDB now parses 0b101010 identically with 42.
3476 set follow-exec-mode new|same
3477 show follow-exec-mode
3478 Control whether GDB reuses the same inferior across an exec call or
3479 creates a new one. This is useful to be able to restart the old
3480 executable after the inferior having done an exec call.
3482 set default-collect EXPR, ...
3483 show default-collect
3484 Define a list of expressions to be collected at each tracepoint.
3485 This is a useful way to ensure essential items are not overlooked,
3486 such as registers or a critical global variable.
3488 set disconnected-tracing
3489 show disconnected-tracing
3490 If set to 1, the target is instructed to continue tracing if it
3491 loses its connection to GDB. If 0, the target is to stop tracing
3494 set circular-trace-buffer
3495 show circular-trace-buffer
3496 If set to on, the target is instructed to use a circular trace buffer
3497 and discard the oldest trace frames instead of stopping the trace due
3498 to a full trace buffer. If set to off, the trace stops when the buffer
3499 fills up. Some targets may not support this.
3501 set script-extension off|soft|strict
3502 show script-extension
3503 If set to "off", the debugger does not perform any script language
3504 recognition, and all sourced files are assumed to be GDB scripts.
3505 If set to "soft" (the default), files are sourced according to
3506 filename extension, falling back to GDB scripts if the first
3508 If set to "strict", files are sourced according to filename extension.
3510 set ada trust-PAD-over-XVS on|off
3511 show ada trust-PAD-over-XVS
3512 If off, activate a workaround against a bug in the debugging information
3513 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3514 the GCC sources for more information about the GNAT encoding and
3515 PAD types in particular). It is always safe to set this option to
3516 off, but this introduces a slight performance penalty. The default
3519 * Python API Improvements
3521 ** GDB provides the new class gdb.LazyString. This is useful in
3522 some pretty-printing cases. The new method gdb.Value.lazy_string
3523 provides a simple way to create objects of this type.
3525 ** The fields returned by gdb.Type.fields now have an
3526 `is_base_class' attribute.
3528 ** The new method gdb.Type.range returns the range of an array type.
3530 ** The new method gdb.parse_and_eval can be used to parse and
3531 evaluate an expression.
3533 * New remote packets
3536 Define a trace state variable.
3539 Get the current value of a trace state variable.
3542 Set desired tracing behavior upon disconnection.
3545 Set the trace buffer to be linear or circular.
3548 Get data about the tracepoints currently in use.
3552 Process record now works correctly with hardware watchpoints.
3554 Multiple bug fixes have been made to the mips-irix port, making it
3555 much more reliable. In particular:
3556 - Debugging threaded applications is now possible again. Previously,
3557 GDB would hang while starting the program, or while waiting for
3558 the program to stop at a breakpoint.
3559 - Attaching to a running process no longer hangs.
3560 - An error occurring while loading a core file has been fixed.
3561 - Changing the value of the PC register now works again. This fixes
3562 problems observed when using the "jump" command, or when calling
3563 a function from GDB, or even when assigning a new value to $pc.
3564 - With the "finish" and "return" commands, the return value for functions
3565 returning a small array is now correctly printed.
3566 - It is now possible to break on shared library code which gets executed
3567 during a shared library init phase (code executed while executing
3568 their .init section). Previously, the breakpoint would have no effect.
3569 - GDB is now able to backtrace through the signal handler for
3570 non-threaded programs.
3572 PIE (Position Independent Executable) programs debugging is now supported.
3573 This includes debugging execution of PIC (Position Independent Code) shared
3574 libraries although for that, it should be possible to run such libraries as an
3577 *** Changes in GDB 7.0
3579 * GDB now has an interface for JIT compilation. Applications that
3580 dynamically generate code can create symbol files in memory and register
3581 them with GDB. For users, the feature should work transparently, and
3582 for JIT developers, the interface is documented in the GDB manual in the
3583 "JIT Compilation Interface" chapter.
3585 * Tracepoints may now be conditional. The syntax is as for
3586 breakpoints; either an "if" clause appended to the "trace" command,
3587 or the "condition" command is available. GDB sends the condition to
3588 the target for evaluation using the same bytecode format as is used
3589 for tracepoint actions.
3591 * The disassemble command now supports: an optional /r modifier, print the
3592 raw instructions in hex as well as in symbolic form, and an optional /m
3593 modifier to print mixed source+assembly.
3595 * Process record and replay
3597 In a architecture environment that supports ``process record and
3598 replay'', ``process record and replay'' target can record a log of
3599 the process execution, and replay it with both forward and reverse
3602 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3603 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3604 set execution-direction {forward|reverse}, for targets that support
3607 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3608 feature is available with a native GDB running on kernel version
3611 * GDB now has support for multi-byte and wide character sets on the
3612 target. Strings whose character type is wchar_t, char16_t, or
3613 char32_t are now correctly printed. GDB supports wide- and unicode-
3614 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3615 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3616 `printf'. This feature requires iconv to work properly; if your
3617 system does not have a working iconv, GDB can use GNU libiconv. See
3618 the installation instructions for more information.
3620 * GDB now supports automatic retrieval of shared library files from
3621 remote targets. To use this feature, specify a system root that begins
3622 with the `remote:' prefix, either via the `set sysroot' command or via
3623 the `--with-sysroot' configure-time option.
3625 * "info sharedlibrary" now takes an optional regex of libraries to show,
3626 and it now reports if a shared library has no debugging information.
3628 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3629 now complete on file names.
3631 * When completing in expressions, gdb will attempt to limit
3632 completions to allowable structure or union fields, where appropriate.
3633 For instance, consider:
3635 # struct example { int f1; double f2; };
3636 # struct example variable;
3639 If the user types TAB at the end of this command line, the available
3640 completions will be "f1" and "f2".
3642 * Inlined functions are now supported. They show up in backtraces, and
3643 the "step", "next", and "finish" commands handle them automatically.
3645 * GDB now supports the token-splicing (##) and stringification (#)
3646 operators when expanding macros. It also supports variable-arity
3649 * GDB now supports inspecting extra signal information, exported by
3650 the new $_siginfo convenience variable. The feature is currently
3651 implemented on linux ARM, i386 and amd64.
3653 * GDB can now display the VFP floating point registers and NEON vector
3654 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3655 can provide these registers (requires Linux 2.6.30 or later). Remote
3656 and simulator targets may also provide them.
3658 * New remote packets
3661 Search memory for a sequence of bytes.
3664 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3665 operation over reliable transport links. Use of this packet is
3666 controlled by the `set remote noack-packet' command.
3669 Kill the process with the specified process ID. Use this in preference
3670 to `k' when multiprocess protocol extensions are supported.
3673 Obtains additional operating system information
3677 Read or write additional signal information.
3679 * Removed remote protocol undocumented extension
3681 An undocumented extension to the remote protocol's `S' stop reply
3682 packet that permited the stub to pass a process id was removed.
3683 Remote servers should use the `T' stop reply packet instead.
3685 * GDB now supports multiple function calling conventions according to the
3686 DWARF-2 DW_AT_calling_convention function attribute.
3688 * The SH target utilizes the aforementioned change to distinguish between gcc
3689 and Renesas calling convention. It also adds the new CLI commands
3690 `set/show sh calling-convention'.
3692 * GDB can now read compressed debug sections, as produced by GNU gold
3693 with the --compress-debug-sections=zlib flag.
3695 * 64-bit core files are now supported on AIX.
3697 * Thread switching is now supported on Tru64.
3699 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3700 which will be allocated using malloc later in program execution.
3702 * The qXfer:libraries:read remote procotol packet now allows passing a
3703 list of section offsets.
3705 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3706 conditions handling signals delivered during attach or thread creation
3707 have also been fixed.
3709 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3710 From the user's standpoint, all unqualified instances of True and False
3711 are treated as the standard definitions, regardless of context.
3713 * GDB now parses C++ symbol and type names more flexibly. For
3716 template<typename T> class C { };
3719 GDB will now correctly handle all of:
3721 ptype C<char const *>
3722 ptype C<char const*>
3723 ptype C<const char *>
3724 ptype C<const char*>
3726 * New features in the GDB remote stub, gdbserver
3728 - The "--wrapper" command-line argument tells gdbserver to use a
3729 wrapper program to launch programs for debugging.
3731 - On PowerPC and S/390 targets, it is now possible to use a single
3732 gdbserver executable to debug both 32-bit and 64-bit programs.
3733 (This requires gdbserver itself to be built as a 64-bit executable.)
3735 - gdbserver uses the new noack protocol mode for TCP connections to
3736 reduce communications latency, if also supported and enabled in GDB.
3738 - Support for the sparc64-linux-gnu target is now included in
3741 - The amd64-linux build of gdbserver now supports debugging both
3742 32-bit and 64-bit programs.
3744 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3745 now support hardware watchpoints, and will use them automatically
3750 GDB now has support for scripting using Python. Whether this is
3751 available is determined at configure time.
3753 New GDB commands can now be written in Python.
3755 * Ada tasking support
3757 Ada tasks can now be inspected in GDB. The following commands have
3761 Print the list of Ada tasks.
3763 Print detailed information about task number N.
3765 Print the task number of the current task.
3767 Switch the context of debugging to task number N.
3769 * Support for user-defined prefixed commands. The "define" command can
3770 add new commands to existing prefixes, e.g. "target".
3772 * Multi-inferior, multi-process debugging.
3774 GDB now has generalized support for multi-inferior debugging. See
3775 "Debugging Multiple Inferiors" in the manual for more information.
3776 Although availability still depends on target support, the command
3777 set is more uniform now. The GNU/Linux specific multi-forks support
3778 has been migrated to this new framework. This implied some user
3779 visible changes; see "New commands" and also "Removed commands"
3782 * Target descriptions can now describe the target OS ABI. See the
3783 "Target Description Format" section in the user manual for more
3786 * Target descriptions can now describe "compatible" architectures
3787 to indicate that the target can execute applications for a different
3788 architecture in addition to those for the main target architecture.
3789 See the "Target Description Format" section in the user manual for
3792 * Multi-architecture debugging.
3794 GDB now includes general supports for debugging applications on
3795 hybrid systems that use more than one single processor architecture
3796 at the same time. Each such hybrid architecture still requires
3797 specific support to be added. The only hybrid architecture supported
3798 in this version of GDB is the Cell Broadband Engine.
3800 * GDB now supports integrated debugging of Cell/B.E. applications that
3801 use both the PPU and SPU architectures. To enable support for hybrid
3802 Cell/B.E. debugging, you need to configure GDB to support both the
3803 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3804 --enable-targets configure option.
3806 * Non-stop mode debugging.
3808 For some targets, GDB now supports an optional mode of operation in
3809 which you can examine stopped threads while other threads continue
3810 to execute freely. This is referred to as non-stop mode, with the
3811 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3812 section in the user manual for more information.
3814 To be able to support remote non-stop debugging, a remote stub needs
3815 to implement the non-stop mode remote protocol extensions, as
3816 described in the "Remote Non-Stop" section of the user manual. The
3817 GDB remote stub, gdbserver, has been adjusted to support these
3818 extensions on linux targets.
3820 * New commands (for set/show, see "New options" below)
3822 catch syscall [NAME(S) | NUMBER(S)]
3823 Catch system calls. Arguments, which should be names of system
3824 calls or their numbers, mean catch only those syscalls. Without
3825 arguments, every syscall will be caught. When the inferior issues
3826 any of the specified syscalls, GDB will stop and announce the system
3827 call, both when it is called and when its call returns. This
3828 feature is currently available with a native GDB running on the
3829 Linux Kernel, under the following architectures: x86, x86_64,
3830 PowerPC and PowerPC64.
3832 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3834 Search memory for a sequence of bytes.
3836 maint set python print-stack
3837 maint show python print-stack
3838 Show a stack trace when an error is encountered in a Python script.
3841 Invoke CODE by passing it to the Python interpreter.
3846 These allow macros to be defined, undefined, and listed
3850 Show operating system information about processes.
3853 List the inferiors currently under GDB's control.
3856 Switch focus to inferior number NUM.
3859 Detach from inferior number NUM.
3862 Kill inferior number NUM.
3866 set spu stop-on-load
3867 show spu stop-on-load
3868 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3870 set spu auto-flush-cache
3871 show spu auto-flush-cache
3872 Control whether to automatically flush the software-managed cache
3873 during Cell/B.E. debugging.
3875 set sh calling-convention
3876 show sh calling-convention
3877 Control the calling convention used when calling SH target functions.
3880 show debug timestamp
3881 Control display of timestamps with GDB debugging output.
3883 set disassemble-next-line
3884 show disassemble-next-line
3885 Control display of disassembled source lines or instructions when
3888 set remote noack-packet
3889 show remote noack-packet
3890 Set/show the use of remote protocol QStartNoAckMode packet. See above
3891 under "New remote packets."
3893 set remote query-attached-packet
3894 show remote query-attached-packet
3895 Control use of remote protocol `qAttached' (query-attached) packet.
3897 set remote read-siginfo-object
3898 show remote read-siginfo-object
3899 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3902 set remote write-siginfo-object
3903 show remote write-siginfo-object
3904 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3907 set remote reverse-continue
3908 show remote reverse-continue
3909 Control use of remote protocol 'bc' (reverse-continue) packet.
3911 set remote reverse-step
3912 show remote reverse-step
3913 Control use of remote protocol 'bs' (reverse-step) packet.
3915 set displaced-stepping
3916 show displaced-stepping
3917 Control displaced stepping mode. Displaced stepping is a way to
3918 single-step over breakpoints without removing them from the debuggee.
3919 Also known as "out-of-line single-stepping".
3922 show debug displaced
3923 Control display of debugging info for displaced stepping.
3925 maint set internal-error
3926 maint show internal-error
3927 Control what GDB does when an internal error is detected.
3929 maint set internal-warning
3930 maint show internal-warning
3931 Control what GDB does when an internal warning is detected.
3936 Use a wrapper program to launch programs for debugging.
3938 set multiple-symbols (all|ask|cancel)
3939 show multiple-symbols
3940 The value of this variable can be changed to adjust the debugger behavior
3941 when an expression or a breakpoint location contains an ambiguous symbol
3942 name (an overloaded function name, for instance).
3944 set breakpoint always-inserted
3945 show breakpoint always-inserted
3946 Keep breakpoints always inserted in the target, as opposed to inserting
3947 them when resuming the target, and removing them when the target stops.
3948 This option can improve debugger performance on slow remote targets.
3950 set arm fallback-mode (arm|thumb|auto)
3951 show arm fallback-mode
3952 set arm force-mode (arm|thumb|auto)
3954 These commands control how ARM GDB determines whether instructions
3955 are ARM or Thumb. The default for both settings is auto, which uses
3956 the current CPSR value for instructions without symbols; previous
3957 versions of GDB behaved as if "set arm fallback-mode arm".
3959 set disable-randomization
3960 show disable-randomization
3961 Standalone programs run with the virtual address space randomization enabled
3962 by default on some platforms. This option keeps the addresses stable across
3963 multiple debugging sessions.
3967 Control whether other threads are stopped or not when some thread hits
3972 Requests that asynchronous execution is enabled in the target, if available.
3973 In this case, it's possible to resume target in the background, and interact
3974 with GDB while the target is running. "show target-async" displays the
3975 current state of asynchronous execution of the target.
3977 set target-wide-charset
3978 show target-wide-charset
3979 The target-wide-charset is the name of the character set that GDB
3980 uses when printing characters whose type is wchar_t.
3982 set tcp auto-retry (on|off)
3984 set tcp connect-timeout
3985 show tcp connect-timeout
3986 These commands allow GDB to retry failed TCP connections to a remote stub
3987 with a specified timeout period; this is useful if the stub is launched
3988 in parallel with GDB but may not be ready to accept connections immediately.
3990 set libthread-db-search-path
3991 show libthread-db-search-path
3992 Control list of directories which GDB will search for appropriate
3995 set schedule-multiple (on|off)
3996 show schedule-multiple
3997 Allow GDB to resume all threads of all processes or only threads of
3998 the current process.
4002 Use more aggressive caching for accesses to the stack. This improves
4003 performance of remote debugging (particularly backtraces) without
4004 affecting correctness.
4006 set interactive-mode (on|off|auto)
4007 show interactive-mode
4008 Control whether GDB runs in interactive mode (on) or not (off).
4009 When in interactive mode, GDB waits for the user to answer all
4010 queries. Otherwise, GDB does not wait and assumes the default
4011 answer. When set to auto (the default), GDB determines which
4012 mode to use based on the stdin settings.
4017 For program forks, this is replaced by the new more generic `info
4018 inferiors' command. To list checkpoints, you can still use the
4019 `info checkpoints' command, which was an alias for the `info forks'
4023 Replaced by the new `inferior' command. To switch between
4024 checkpoints, you can still use the `restart' command, which was an
4025 alias for the `fork' command.
4028 This is removed, since some targets don't have a notion of
4029 processes. To switch between processes, you can still use the
4030 `inferior' command using GDB's own inferior number.
4033 For program forks, this is replaced by the new more generic `kill
4034 inferior' command. To delete a checkpoint, you can still use the
4035 `delete checkpoint' command, which was an alias for the `delete
4039 For program forks, this is replaced by the new more generic `detach
4040 inferior' command. To detach a checkpoint, you can still use the
4041 `detach checkpoint' command, which was an alias for the `detach
4044 * New native configurations
4046 x86/x86_64 Darwin i[34567]86-*-darwin*
4048 x86_64 MinGW x86_64-*-mingw*
4052 Lattice Mico32 lm32-*
4053 x86 DICOS i[34567]86-*-dicos*
4054 x86_64 DICOS x86_64-*-dicos*
4057 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4058 (mingw32ce) debugging.
4064 These commands were actually not implemented on any target.
4066 *** Changes in GDB 6.8
4068 * New native configurations
4070 NetBSD/hppa hppa*-*netbsd*
4071 Xtensa GNU/Linux xtensa*-*-linux*
4075 NetBSD/hppa hppa*-*-netbsd*
4076 Xtensa GNU/Lunux xtensa*-*-linux*
4078 * Change in command line behavior -- corefiles vs. process ids.
4080 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4081 attaching to process NUMBER fails, GDB no longer attempts to open a
4082 core file named NUMBER. Attaching to a program using the -c option
4083 is no longer supported. Instead, use the '-p' or '--pid' options.
4085 * GDB can now be built as a native debugger for debugging Windows x86
4086 (mingw32) Portable Executable (PE) programs.
4088 * Pending breakpoints no longer change their number when their address
4091 * GDB now supports breakpoints with multiple locations,
4092 including breakpoints on C++ constructors, inside C++ templates,
4093 and in inlined functions.
4095 * GDB's ability to debug optimized code has been improved. GDB more
4096 accurately identifies function bodies and lexical blocks that occupy
4097 more than one contiguous range of addresses.
4099 * Target descriptions can now describe registers for PowerPC.
4101 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4102 registers on PowerPC targets.
4104 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4105 targets even when the libthread_db library is not available.
4107 * The GDB remote stub, gdbserver, now supports the new file transfer
4108 commands (remote put, remote get, and remote delete).
4110 * The GDB remote stub, gdbserver, now supports run and attach in
4111 extended-remote mode.
4113 * hppa*64*-*-hpux11* target broken
4114 The debugger is unable to start a program and fails with the following
4115 error: "Error trying to get information about dynamic linker".
4116 The gdb-6.7 release is also affected.
4118 * GDB now supports the --enable-targets= configure option to allow
4119 building a single GDB executable that supports multiple remote
4120 target architectures.
4122 * GDB now supports debugging C and C++ programs which use the
4123 Decimal Floating Point extension. In addition, the PowerPC target
4124 now has a set of pseudo-registers to inspect decimal float values
4125 stored in two consecutive float registers.
4127 * The -break-insert MI command can optionally create pending
4130 * Improved support for debugging Ada
4131 Many improvements to the Ada language support have been made. These
4133 - Better support for Ada2005 interface types
4134 - Improved handling of arrays and slices in general
4135 - Better support for Taft-amendment types
4136 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4138 - Improved command completion in Ada
4141 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4146 set print frame-arguments (all|scalars|none)
4147 show print frame-arguments
4148 The value of this variable can be changed to control which argument
4149 values should be printed by the debugger when displaying a frame.
4154 Transfer files to and from a remote target, and delete remote files.
4161 Transfer files to and from a remote target, and delete remote files.
4163 * New remote packets
4170 Open, close, read, write, and delete files on the remote system.
4173 Attach to an existing process on the remote system, in extended-remote
4177 Run a new process on the remote system, in extended-remote mode.
4179 *** Changes in GDB 6.7
4181 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4182 bfd, libiberty and opcodes, as revealed by static analysis donated by
4183 Coverity, Inc. (http://scan.coverity.com).
4185 * When looking up multiply-defined global symbols, GDB will now prefer the
4186 symbol definition in the current shared library if it was built using the
4187 -Bsymbolic linker option.
4189 * When the Text User Interface (TUI) is not configured, GDB will now
4190 recognize the -tui command-line option and print a message that the TUI
4193 * The GDB remote stub, gdbserver, now has lower overhead for high
4194 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4196 * GDB for MIPS targets now autodetects whether a remote target provides
4197 32-bit or 64-bit register values.
4199 * Support for C++ member pointers has been improved.
4201 * GDB now understands XML target descriptions, which specify the
4202 target's overall architecture. GDB can read a description from
4203 a local file or over the remote serial protocol.
4205 * Vectors of single-byte data use a new integer type which is not
4206 automatically displayed as character or string data.
4208 * The /s format now works with the print command. It displays
4209 arrays of single-byte integers and pointers to single-byte integers
4212 * Target descriptions can now describe target-specific registers,
4213 for architectures which have implemented the support (currently
4214 only ARM, M68K, and MIPS).
4216 * GDB and the GDB remote stub, gdbserver, now support the XScale
4219 * The GDB remote stub, gdbserver, has been updated to support
4220 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4221 has been rewritten to use the standard GDB remote protocol.
4223 * GDB can now step into C++ functions which are called through thunks.
4225 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4227 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4228 layout. It also supports a TextSeg= and DataSeg= response when only
4229 segment base addresses (rather than offsets) are available.
4231 * The /i format now outputs any trailing branch delay slot instructions
4232 immediately following the last instruction within the count specified.
4234 * The GDB remote protocol "T" stop reply packet now supports a
4235 "library" response. Combined with the new "qXfer:libraries:read"
4236 packet, this response allows GDB to debug shared libraries on targets
4237 where the operating system manages the list of loaded libraries (e.g.
4238 Windows and SymbianOS).
4240 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4241 (DLLs) on Windows and Windows CE targets.
4243 * GDB now supports a faster verification that a .debug file matches its binary
4244 according to its build-id signature, if the signature is present.
4250 Enable or disable hardware flow control (RTS/CTS) on the serial port
4251 when debugging using remote targets.
4253 set mem inaccessible-by-default
4254 show mem inaccessible-by-default
4255 If the target supplies a memory map, for instance via the remote
4256 protocol's "qXfer:memory-map:read" packet, setting this variable
4257 prevents GDB from accessing memory outside the memory map. This
4258 is useful for targets with memory mapped registers or which react
4259 badly to accesses of unmapped address space.
4261 set breakpoint auto-hw
4262 show breakpoint auto-hw
4263 If the target supplies a memory map, for instance via the remote
4264 protocol's "qXfer:memory-map:read" packet, setting this variable
4265 lets GDB use hardware breakpoints automatically for memory regions
4266 where it can not use software breakpoints. This covers both the
4267 "break" command and internal breakpoints used for other commands
4268 including "next" and "finish".
4271 catch exception unhandled
4272 Stop the program execution when Ada exceptions are raised.
4275 Stop the program execution when an Ada assertion failed.
4279 Set an alternate system root for target files. This is a more
4280 general version of "set solib-absolute-prefix", which is now
4281 an alias to "set sysroot".
4284 Provide extended SPU facility status information. This set of
4285 commands is available only when debugging the Cell/B.E. SPU
4288 * New native configurations
4290 OpenBSD/sh sh*-*openbsd*
4293 unset tdesc filename
4295 Use the specified local file as an XML target description, and do
4296 not query the target for its built-in description.
4300 OpenBSD/sh sh*-*-openbsd*
4301 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4302 Toshiba Media Processor mep-elf
4304 * New remote packets
4307 Ignore the specified signals; pass them directly to the debugged program
4308 without stopping other threads or reporting them to GDB.
4310 qXfer:features:read:
4311 Read an XML target description from the target, which describes its
4316 Read or write contents of an spufs file on the target system. These
4317 packets are available only on the Cell/B.E. SPU architecture.
4319 qXfer:libraries:read:
4320 Report the loaded shared libraries. Combined with new "T" packet
4321 response, this packet allows GDB to debug shared libraries on
4322 targets where the operating system manages the list of loaded
4323 libraries (e.g. Windows and SymbianOS).
4327 Support for these obsolete configurations has been removed.
4335 i[34567]86-*-lynxos*
4336 i[34567]86-*-netware*
4337 i[34567]86-*-sco3.2v5*
4338 i[34567]86-*-sco3.2v4*
4340 i[34567]86-*-sysv4.2*
4343 i[34567]86-*-unixware2*
4344 i[34567]86-*-unixware*
4353 * Other removed features
4360 Various m68k-only ROM monitors.
4367 Various Renesas ROM monitors and debugging interfaces for SH and
4372 Support for a Macraigor serial interface to on-chip debugging.
4373 GDB does not directly support the newer parallel or USB
4378 A debug information format. The predecessor to DWARF 2 and
4379 DWARF 3, which are still supported.
4381 Support for the HP aCC compiler on HP-UX/PA-RISC
4383 SOM-encapsulated symbolic debugging information, automatic
4384 invocation of pxdb, and the aCC custom C++ ABI. This does not
4385 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4386 with aCC can still be debugged on an assembly level.
4388 MIPS ".pdr" sections
4390 A MIPS-specific format used to describe stack frame layout
4391 in debugging information.
4395 GDB could work with an older version of Guile to debug
4396 the interpreter and Scheme programs running in it.
4398 set mips stack-arg-size
4399 set mips saved-gpreg-size
4401 Use "set mips abi" to control parameter passing for MIPS.
4403 *** Changes in GDB 6.6
4408 Cell Broadband Engine SPU spu-elf
4410 * GDB can now be configured as a cross-debugger targeting native Windows
4411 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4412 running on a Windows system over TCP/IP to debug Windows programs.
4414 * The GDB remote stub, gdbserver, has been updated to support Windows and
4415 Cygwin debugging. Both single-threaded and multi-threaded programs are
4418 * The "set trust-readonly-sections" command works again. This command was
4419 broken in GDB 6.3, 6.4, and 6.5.
4421 * The "load" command now supports writing to flash memory, if the remote
4422 stub provides the required support.
4424 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4425 longer requires symbolic debug information (e.g. DWARF-2).
4430 unset substitute-path
4431 show substitute-path
4432 Manage a list of substitution rules that GDB uses to rewrite the name
4433 of the directories where the sources are located. This can be useful
4434 for instance when the sources were moved to a different location
4435 between compilation and debugging.
4439 Print each CLI command as it is executed. Each command is prefixed with
4440 a number of `+' symbols representing the nesting depth.
4441 The source command now has a `-v' option to enable the same feature.
4445 The ARM Demon monitor support (RDP protocol, "target rdp").
4447 Kernel Object Display, an embedded debugging feature which only worked with
4448 an obsolete version of Cisco IOS.
4450 The 'set download-write-size' and 'show download-write-size' commands.
4452 * New remote packets
4455 Tell a stub about GDB client features, and request remote target features.
4456 The first feature implemented is PacketSize, which allows the target to
4457 specify the size of packets it can handle - to minimize the number of
4458 packets required and improve performance when connected to a remote
4462 Fetch an OS auxilliary vector from the remote stub. This packet is a
4463 more efficient replacement for qPart:auxv:read.
4465 qXfer:memory-map:read:
4466 Fetch a memory map from the remote stub, including information about
4467 RAM, ROM, and flash memory devices.
4472 Erase and program a flash memory device.
4474 * Removed remote packets
4477 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4478 used it, and only gdbserver implemented it.
4480 *** Changes in GDB 6.5
4484 Renesas M32C/M16C m32c-elf
4486 Morpho Technologies ms1 ms1-elf
4490 init-if-undefined Initialize a convenience variable, but
4491 only if it doesn't already have a value.
4493 The following commands are presently only implemented for native GNU/Linux:
4495 checkpoint Save a snapshot of the program state.
4497 restart <n> Return the program state to a
4498 previously saved state.
4500 info checkpoints List currently saved checkpoints.
4502 delete-checkpoint <n> Delete a previously saved checkpoint.
4504 set|show detach-on-fork Tell gdb whether to detach from a newly
4505 forked process, or to keep debugging it.
4507 info forks List forks of the user program that
4508 are available to be debugged.
4510 fork <n> Switch to debugging one of several
4511 forks of the user program that are
4512 available to be debugged.
4514 delete-fork <n> Delete a fork from the list of forks
4515 that are available to be debugged (and
4516 kill the forked process).
4518 detach-fork <n> Delete a fork from the list of forks
4519 that are available to be debugged (and
4520 allow the process to continue).
4524 Morpho Technologies ms2 ms1-elf
4526 * Improved Windows host support
4528 GDB now builds as a cross debugger hosted on i686-mingw32, including
4529 native console support, and remote communications using either
4530 network sockets or serial ports.
4532 * Improved Modula-2 language support
4534 GDB can now print most types in the Modula-2 syntax. This includes:
4535 basic types, set types, record types, enumerated types, range types,
4536 pointer types and ARRAY types. Procedure var parameters are correctly
4537 printed and hexadecimal addresses and character constants are also
4538 written in the Modula-2 syntax. Best results can be obtained by using
4539 GNU Modula-2 together with the -gdwarf-2 command line option.
4543 The ARM rdi-share module.
4545 The Netware NLM debug server.
4547 *** Changes in GDB 6.4
4549 * New native configurations
4551 OpenBSD/arm arm*-*-openbsd*
4552 OpenBSD/mips64 mips64-*-openbsd*
4556 Morpho Technologies ms1 ms1-elf
4558 * New command line options
4560 --batch-silent As for --batch, but totally silent.
4561 --return-child-result The debugger will exist with the same value
4562 the child (debugged) program exited with.
4563 --eval-command COMMAND, -ex COMMAND
4564 Execute a single GDB CLI command. This may be
4565 specified multiple times and in conjunction
4566 with the --command (-x) option.
4568 * Deprecated commands removed
4570 The following commands, that were deprecated in 2000, have been
4574 set|show arm disassembly-flavor set|show arm disassembler
4575 othernames set arm disassembler
4576 set|show remotedebug set|show debug remote
4577 set|show archdebug set|show debug arch
4578 set|show eventdebug set|show debug event
4581 * New BSD user-level threads support
4583 It is now possible to debug programs using the user-level threads
4584 library on OpenBSD and FreeBSD. Currently supported (target)
4587 FreeBSD/amd64 x86_64-*-freebsd*
4588 FreeBSD/i386 i386-*-freebsd*
4589 OpenBSD/i386 i386-*-openbsd*
4591 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4592 are not yet supported.
4594 * New support for Matsushita MN10300 w/sim added
4595 (Work in progress). mn10300-elf.
4597 * REMOVED configurations and files
4599 VxWorks and the XDR protocol *-*-vxworks
4600 Motorola MCORE mcore-*-*
4601 National Semiconductor NS32000 ns32k-*-*
4603 * New "set print array-indexes" command
4605 After turning this setting "on", GDB prints the index of each element
4606 when displaying arrays. The default is "off" to preserve the previous
4609 * VAX floating point support
4611 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4613 * User-defined command support
4615 In addition to using $arg0..$arg9 for argument passing, it is now possible
4616 to use $argc to determine now many arguments have been passed. See the
4617 section on user-defined commands in the user manual for more information.
4619 *** Changes in GDB 6.3:
4621 * New command line option
4623 GDB now accepts -l followed by a number to set the timeout for remote
4626 * GDB works with GCC -feliminate-dwarf2-dups
4628 GDB now supports a more compact representation of DWARF-2 debug
4629 information using DW_FORM_ref_addr references. These are produced
4630 by GCC with the option -feliminate-dwarf2-dups and also by some
4631 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4632 to use -feliminate-dwarf2-dups.
4634 * Internationalization
4636 When supported by the host system, GDB will be built with
4637 internationalization (libintl). The task of marking up the sources is
4638 continued, we're looking forward to our first translation.
4642 Initial support for debugging programs compiled with the GNAT
4643 implementation of the Ada programming language has been integrated
4644 into GDB. In this release, support is limited to expression evaluation.
4646 * New native configurations
4648 GNU/Linux/m32r m32r-*-linux-gnu
4652 GDB's remote protocol now includes support for the 'p' packet. This
4653 packet is used to fetch individual registers from a remote inferior.
4655 * END-OF-LIFE registers[] compatibility module
4657 GDB's internal register infrastructure has been completely rewritten.
4658 The new infrastructure making possible the implementation of key new
4659 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4662 GDB 6.3 will be the last release to include the the registers[]
4663 compatibility module that allowed out-of-date configurations to
4664 continue to work. This change directly impacts the following
4674 powerpc bdm protocol
4676 Unless there is activity to revive these configurations, they will be
4677 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4679 * OBSOLETE configurations and files
4681 Configurations that have been declared obsolete in this release have
4682 been commented out. Unless there is activity to revive these
4683 configurations, the next release of GDB will have their sources
4684 permanently REMOVED.
4693 *** Changes in GDB 6.2.1:
4695 * MIPS `break main; run' gave an heuristic-fence-post warning
4697 When attempting to run even a simple program, a warning about
4698 heuristic-fence-post being hit would be reported. This problem has
4701 * MIPS IRIX 'long double' crashed GDB
4703 When examining a long double variable, GDB would get a segmentation
4704 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4705 IRIX long double values).
4709 A bug in the VAX stack code was causing problems with the "next"
4710 command. This problem has been fixed.
4712 *** Changes in GDB 6.2:
4714 * Fix for ``many threads''
4716 On GNU/Linux systems that use the NPTL threads library, a program
4717 rapidly creating and deleting threads would confuse GDB leading to the
4720 ptrace: No such process.
4721 thread_db_get_info: cannot get thread info: generic error
4723 This problem has been fixed.
4725 * "-async" and "-noasync" options removed.
4727 Support for the broken "-noasync" option has been removed (it caused
4730 * New ``start'' command.
4732 This command runs the program until the begining of the main procedure.
4734 * New BSD Kernel Data Access Library (libkvm) interface
4736 Using ``target kvm'' it is now possible to debug kernel core dumps and
4737 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4738 platforms. Currently supported (native-only) configurations are:
4740 FreeBSD/amd64 x86_64-*-freebsd*
4741 FreeBSD/i386 i?86-*-freebsd*
4742 NetBSD/i386 i?86-*-netbsd*
4743 NetBSD/m68k m68*-*-netbsd*
4744 NetBSD/sparc sparc-*-netbsd*
4745 OpenBSD/amd64 x86_64-*-openbsd*
4746 OpenBSD/i386 i?86-*-openbsd*
4747 OpenBSD/m68k m68*-openbsd*
4748 OpenBSD/sparc sparc-*-openbsd*
4750 * Signal trampoline code overhauled
4752 Many generic problems with GDB's signal handling code have been fixed.
4753 These include: backtraces through non-contiguous stacks; recognition
4754 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4755 call; backtrace through a signal trampoline; step into and out of
4756 signal handlers; and single-stepping in the signal trampoline.
4758 Please note that kernel bugs are a limiting factor here. These
4759 features have been shown to work on an s390 GNU/Linux system that
4760 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4762 * Cygwin support for DWARF 2 added.
4764 * New native configurations
4766 GNU/Linux/hppa hppa*-*-linux*
4767 OpenBSD/hppa hppa*-*-openbsd*
4768 OpenBSD/m68k m68*-*-openbsd*
4769 OpenBSD/m88k m88*-*-openbsd*
4770 OpenBSD/powerpc powerpc-*-openbsd*
4771 NetBSD/vax vax-*-netbsd*
4772 OpenBSD/vax vax-*-openbsd*
4774 * END-OF-LIFE frame compatibility module
4776 GDB's internal frame infrastructure has been completely rewritten.
4777 The new infrastructure making it possible to support key new features
4778 including DWARF 2 Call Frame Information. To aid in the task of
4779 migrating old configurations to this new infrastructure, a
4780 compatibility module, that allowed old configurations to continue to
4781 work, was also included.
4783 GDB 6.2 will be the last release to include this frame compatibility
4784 module. This change directly impacts the following configurations:
4794 Unless there is activity to revive these configurations, they will be
4795 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4797 * REMOVED configurations and files
4799 Sun 3, running SunOS 3 m68*-*-sunos3*
4800 Sun 3, running SunOS 4 m68*-*-sunos4*
4801 Sun 2, running SunOS 3 m68000-*-sunos3*
4802 Sun 2, running SunOS 4 m68000-*-sunos4*
4803 Motorola 680x0 running LynxOS m68*-*-lynxos*
4804 AT&T 3b1/Unix pc m68*-att-*
4805 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4806 decstation mips-dec-* mips-little-*
4807 riscos mips-*-riscos* mips-*-sysv*
4808 sonymips mips-sony-*
4809 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4811 *** Changes in GDB 6.1.1:
4813 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4815 The TUI (Text-mode User Interface) is now built as part of a default
4816 GDB configuration. It is enabled by either selecting the TUI with the
4817 command line option "-i=tui" or by running the separate "gdbtui"
4818 program. For more information on the TUI, see the manual "Debugging
4821 * Pending breakpoint support (also included in GDB 6.1)
4823 Support has been added to allow you to specify breakpoints in shared
4824 libraries that have not yet been loaded. If a breakpoint location
4825 cannot be found, and the "breakpoint pending" option is set to auto,
4826 GDB queries you if you wish to make the breakpoint pending on a future
4827 shared-library load. If and when GDB resolves the breakpoint symbol,
4828 the pending breakpoint is removed as one or more regular breakpoints
4831 Pending breakpoints are very useful for GCJ Java debugging.
4833 * Fixed ISO-C build problems
4835 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4836 non ISO-C code that stopped them being built using a more strict ISO-C
4837 compiler (e.g., IBM's C compiler).
4839 * Fixed build problem on IRIX 5
4841 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4842 wasn't able to compile compile on an IRIX 5 system.
4844 * Added execute permission to gdb/gdbserver/configure
4846 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4847 permission. This bug would cause configure to fail on a number of
4848 systems (Solaris, IRIX). Ref: server/519.
4850 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4852 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4853 has been updated to use constant array sizes.
4855 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4857 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4858 its generated DWARF Call Frame Info. This encoding was causing GDB to
4859 panic, that panic has been fixed. Ref: gdb/1628.
4861 * Fixed a problem when examining parameters in shared library code.
4863 When examining parameters in optimized shared library code generated
4864 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4865 not available''. GDB now correctly displays the variable's value.
4867 *** Changes in GDB 6.1:
4869 * Removed --with-mmalloc
4871 Support for the mmalloc memory manager has been removed, as it
4872 conflicted with the internal gdb byte cache.
4874 * Changes in AMD64 configurations
4876 The AMD64 target now includes the %cs and %ss registers. As a result
4877 the AMD64 remote protocol has changed; this affects the floating-point
4878 and SSE registers. If you rely on those registers for your debugging,
4879 you should upgrade gdbserver on the remote side.
4881 * Revised SPARC target
4883 The SPARC target has been completely revised, incorporating the
4884 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4885 support for LynxOS and SunOS 4 has been dropped. Calling functions
4886 from within GDB on operating systems with a non-executable stack
4887 (Solaris, OpenBSD) now works.
4891 GDB has a new C++ demangler which does a better job on the mangled
4892 names generated by current versions of g++. It also runs faster, so
4893 with this and other changes gdb should now start faster on large C++
4896 * DWARF 2 Location Expressions
4898 GDB support for location expressions has been extended to support function
4899 arguments and frame bases. Older versions of GDB could crash when they
4902 * C++ nested types and namespaces
4904 GDB's support for nested types and namespaces in C++ has been
4905 improved, especially if you use the DWARF 2 debugging format. (This
4906 is the default for recent versions of GCC on most platforms.)
4907 Specifically, if you have a class "Inner" defined within a class or
4908 namespace "Outer", then GDB realizes that the class's name is
4909 "Outer::Inner", not simply "Inner". This should greatly reduce the
4910 frequency of complaints about not finding RTTI symbols. In addition,
4911 if you are stopped at inside of a function defined within a namespace,
4912 GDB modifies its name lookup accordingly.
4914 * New native configurations
4916 NetBSD/amd64 x86_64-*-netbsd*
4917 OpenBSD/amd64 x86_64-*-openbsd*
4918 OpenBSD/alpha alpha*-*-openbsd*
4919 OpenBSD/sparc sparc-*-openbsd*
4920 OpenBSD/sparc64 sparc64-*-openbsd*
4922 * New debugging protocols
4924 M32R with SDI protocol m32r-*-elf*
4926 * "set prompt-escape-char" command deleted.
4928 The command "set prompt-escape-char" has been deleted. This command,
4929 and its very obscure effet on GDB's prompt, was never documented,
4930 tested, nor mentioned in the NEWS file.
4932 * OBSOLETE configurations and files
4934 Configurations that have been declared obsolete in this release have
4935 been commented out. Unless there is activity to revive these
4936 configurations, the next release of GDB will have their sources
4937 permanently REMOVED.
4939 Sun 3, running SunOS 3 m68*-*-sunos3*
4940 Sun 3, running SunOS 4 m68*-*-sunos4*
4941 Sun 2, running SunOS 3 m68000-*-sunos3*
4942 Sun 2, running SunOS 4 m68000-*-sunos4*
4943 Motorola 680x0 running LynxOS m68*-*-lynxos*
4944 AT&T 3b1/Unix pc m68*-att-*
4945 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4946 decstation mips-dec-* mips-little-*
4947 riscos mips-*-riscos* mips-*-sysv*
4948 sonymips mips-sony-*
4949 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4951 * REMOVED configurations and files
4953 SGI Irix-4.x mips-sgi-irix4 or iris4
4954 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4955 Z8000 simulator z8k-zilog-none or z8ksim
4956 Matsushita MN10200 w/simulator mn10200-*-*
4957 H8/500 simulator h8500-hitachi-hms or h8500hms
4958 HP/PA running BSD hppa*-*-bsd*
4959 HP/PA running OSF/1 hppa*-*-osf*
4960 HP/PA Pro target hppa*-*-pro*
4961 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4962 386BSD i[3456]86-*-bsd*
4963 Sequent family i[3456]86-sequent-sysv4*
4964 i[3456]86-sequent-sysv*
4965 i[3456]86-sequent-bsd*
4966 SPARC running LynxOS sparc-*-lynxos*
4967 SPARC running SunOS 4 sparc-*-sunos4*
4968 Tsqware Sparclet sparclet-*-*
4969 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4971 *** Changes in GDB 6.0:
4975 Support for debugging the Objective-C programming language has been
4976 integrated into GDB.
4978 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4980 DWARF 2's Call Frame Information makes available compiler generated
4981 information that more exactly describes the program's run-time stack.
4982 By using this information, GDB is able to provide more robust stack
4985 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4986 have been updated to use a new backtrace mechanism which includes
4987 DWARF 2 CFI support.
4991 GDB's remote protocol has been extended to include support for hosted
4992 file I/O (where the remote target uses GDB's file system). See GDB's
4993 remote protocol documentation for details.
4995 * All targets using the new architecture framework.
4997 All of GDB's targets have been updated to use the new internal
4998 architecture framework. The way is now open for future GDB releases
4999 to include cross-architecture native debugging support (i386 on amd64,
5002 * GNU/Linux's Thread Local Storage (TLS)
5004 GDB now includes support for for the GNU/Linux implementation of
5005 per-thread variables.
5007 * GNU/Linux's Native POSIX Thread Library (NPTL)
5009 GDB's thread code has been updated to work with either the new
5010 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5012 * Separate debug info.
5014 GDB, in conjunction with BINUTILS, now supports a mechanism for
5015 automatically loading debug information from a separate file. Instead
5016 of shipping full debug and non-debug versions of system libraries,
5017 system integrators can now instead ship just the stripped libraries
5018 and optional debug files.
5020 * DWARF 2 Location Expressions
5022 DWARF 2 Location Expressions allow the compiler to more completely
5023 describe the location of variables (even in optimized code) to the
5026 GDB now includes preliminary support for location expressions (support
5027 for DW_OP_piece is still missing).
5031 A number of long standing bugs that caused GDB to die while starting a
5032 Java application have been fixed. GDB's Java support is now
5033 considered "useable".
5035 * GNU/Linux support for fork, vfork, and exec.
5037 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5038 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5041 * GDB supports logging output to a file
5043 There are two new commands, "set logging" and "show logging", which can be
5044 used to capture GDB's output to a file.
5046 * The meaning of "detach" has changed for gdbserver
5048 The "detach" command will now resume the application, as documented. To
5049 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5052 * d10v, m68hc11 `regs' command deprecated
5054 The `info registers' command has been updated so that it displays the
5055 registers using a format identical to the old `regs' command.
5059 A new command, "maint set profile on/off", has been added. This command can
5060 be used to enable or disable profiling while running GDB, to profile a
5061 session or a set of commands. In addition there is a new configure switch,
5062 "--enable-profiling", which will cause GDB to be compiled with profiling
5063 data, for more informative profiling results.
5065 * Default MI syntax changed to "mi2".
5067 The default MI (machine interface) syntax, enabled by the command line
5068 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5069 "mi1", can be enabled by specifying the option "-i=mi1".
5071 Support for the original "mi0" syntax (included in GDB 5.0) has been
5074 Fix for gdb/192: removed extraneous space when displaying frame level.
5075 Fix for gdb/672: update changelist is now output in mi list format.
5076 Fix for gdb/702: a -var-assign that updates the value now shows up
5077 in a subsequent -var-update.
5079 * New native configurations.
5081 FreeBSD/amd64 x86_64-*-freebsd*
5083 * Multi-arched targets.
5085 HP/PA HPUX11 hppa*-*-hpux*
5086 Renesas M32R/D w/simulator m32r-*-elf*
5088 * OBSOLETE configurations and files
5090 Configurations that have been declared obsolete in this release have
5091 been commented out. Unless there is activity to revive these
5092 configurations, the next release of GDB will have their sources
5093 permanently REMOVED.
5095 Z8000 simulator z8k-zilog-none or z8ksim
5096 Matsushita MN10200 w/simulator mn10200-*-*
5097 H8/500 simulator h8500-hitachi-hms or h8500hms
5098 HP/PA running BSD hppa*-*-bsd*
5099 HP/PA running OSF/1 hppa*-*-osf*
5100 HP/PA Pro target hppa*-*-pro*
5101 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5102 Sequent family i[3456]86-sequent-sysv4*
5103 i[3456]86-sequent-sysv*
5104 i[3456]86-sequent-bsd*
5105 Tsqware Sparclet sparclet-*-*
5106 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5108 * REMOVED configurations and files
5111 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5112 IBM AIX PS/2 i[3456]86-*-aix
5113 i386 running Mach 3.0 i[3456]86-*-mach3*
5114 i386 running Mach i[3456]86-*-mach*
5115 i386 running OSF/1 i[3456]86-*osf1mk*
5116 HP/Apollo 68k Family m68*-apollo*-sysv*,
5118 m68*-hp-bsd*, m68*-hp-hpux*
5119 Argonaut Risc Chip (ARC) arc-*-*
5120 Mitsubishi D30V d30v-*-*
5121 Fujitsu FR30 fr30-*-elf*
5122 OS/9000 i[34]86-*-os9k
5123 I960 with MON960 i960-*-coff
5125 * MIPS $fp behavior changed
5127 The convenience variable $fp, for the MIPS, now consistently returns
5128 the address of the current frame's base. Previously, depending on the
5129 context, $fp could refer to either $sp or the current frame's base
5130 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5131 The GNU Source-Level Debugger''.
5133 *** Changes in GDB 5.3:
5135 * GNU/Linux shared library multi-threaded performance improved.
5137 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5138 `/proc', in preference to `ptrace' for memory reads. This may result
5139 in an improvement in the start-up time of multi-threaded, shared
5140 library applications when run under GDB. One GDB user writes: ``loads
5141 shared libs like mad''.
5143 * ``gdbserver'' now supports multi-threaded applications on some targets
5145 Support for debugging multi-threaded applications which use
5146 the GNU/Linux LinuxThreads package has been added for
5147 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5148 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5150 * GDB now supports C/C++ preprocessor macros.
5152 GDB now expands preprocessor macro invocations in C/C++ expressions,
5153 and provides various commands for showing macro definitions and how
5156 The new command `macro expand EXPRESSION' expands any macro
5157 invocations in expression, and shows the result.
5159 The new command `show macro MACRO-NAME' shows the definition of the
5160 macro named MACRO-NAME, and where it was defined.
5162 Most compilers don't include information about macros in the debugging
5163 information by default. In GCC 3.1, for example, you need to compile
5164 your program with the options `-gdwarf-2 -g3'. If the macro
5165 information is present in the executable, GDB will read it.
5167 * Multi-arched targets.
5169 DEC Alpha (partial) alpha*-*-*
5170 DEC VAX (partial) vax-*-*
5172 National Semiconductor NS32000 (partial) ns32k-*-*
5173 Motorola 68000 (partial) m68k-*-*
5174 Motorola MCORE mcore-*-*
5178 Fujitsu FRV architecture added by Red Hat frv*-*-*
5181 * New native configurations
5183 Alpha NetBSD alpha*-*-netbsd*
5184 SH NetBSD sh*-*-netbsdelf*
5185 MIPS NetBSD mips*-*-netbsd*
5186 UltraSPARC NetBSD sparc64-*-netbsd*
5188 * OBSOLETE configurations and files
5190 Configurations that have been declared obsolete in this release have
5191 been commented out. Unless there is activity to revive these
5192 configurations, the next release of GDB will have their sources
5193 permanently REMOVED.
5195 Mitsubishi D30V d30v-*-*
5196 OS/9000 i[34]86-*-os9k
5197 IBM AIX PS/2 i[3456]86-*-aix
5198 Fujitsu FR30 fr30-*-elf*
5199 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5200 Argonaut Risc Chip (ARC) arc-*-*
5201 i386 running Mach 3.0 i[3456]86-*-mach3*
5202 i386 running Mach i[3456]86-*-mach*
5203 i386 running OSF/1 i[3456]86-*osf1mk*
5204 HP/Apollo 68k Family m68*-apollo*-sysv*,
5206 m68*-hp-bsd*, m68*-hp-hpux*
5207 I960 with MON960 i960-*-coff
5209 * OBSOLETE languages
5211 CHILL, a Pascal like language used by telecommunications companies.
5213 * REMOVED configurations and files
5215 AMD 29k family via UDI a29k-amd-udi, udi29k
5216 A29K VxWorks a29k-*-vxworks
5217 AMD 29000 embedded, using EBMON a29k-none-none
5218 AMD 29000 embedded with COFF a29k-none-coff
5219 AMD 29000 embedded with a.out a29k-none-aout
5221 testsuite/gdb.hp/gdb.threads-hp/ directory
5223 * New command "set max-user-call-depth <nnn>"
5225 This command allows the user to limit the call depth of user-defined
5226 commands. The default is 1024.
5228 * Changes in FreeBSD/i386 native debugging.
5230 Support for the "generate-core-file" has been added.
5232 * New commands "dump", "append", and "restore".
5234 These commands allow data to be copied from target memory
5235 to a bfd-format or binary file (dump and append), and back
5236 from a file into memory (restore).
5238 * Improved "next/step" support on multi-processor Alpha Tru64.
5240 The previous single-step mechanism could cause unpredictable problems,
5241 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5242 of a software single-step mechanism prevents this.
5244 *** Changes in GDB 5.2.1:
5252 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5253 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5254 Fix, by Joel Brobecker imported from mainline.
5256 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5257 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5258 Fix, by Fred Fish, imported from mainline.
5260 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5261 Surprisingly enough, it works now.
5262 By Michal Ludvig, imported from mainline.
5264 i386 hardware watchpoint support:
5265 avoid misses on second run for some targets.
5266 By Pierre Muller, imported from mainline.
5268 *** Changes in GDB 5.2:
5270 * New command "set trust-readonly-sections on[off]".
5272 This command is a hint that tells gdb that read-only sections
5273 really are read-only (ie. that their contents will not change).
5274 In this mode, gdb will go to the object file rather than the
5275 target to read memory from read-only sections (such as ".text").
5276 This can be a significant performance improvement on some
5277 (notably embedded) targets.
5279 * New command "generate-core-file" (or "gcore").
5281 This new gdb command allows the user to drop a core file of the child
5282 process state at any time. So far it's been implemented only for
5283 GNU/Linux and Solaris, but should be relatively easily ported to other
5284 hosts. Argument is core file name (defaults to core.<pid>).
5286 * New command line option
5288 GDB now accepts --pid or -p followed by a process id.
5290 * Change in command line behavior -- corefiles vs. process ids.
5292 There is a subtle behavior in the way in which GDB handles
5293 command line arguments. The first non-flag argument is always
5294 a program to debug, but the second non-flag argument may either
5295 be a corefile or a process id. Previously, GDB would attempt to
5296 open the second argument as a corefile, and if that failed, would
5297 issue a superfluous error message and then attempt to attach it as
5298 a process. Now, if the second argument begins with a non-digit,
5299 it will be treated as a corefile. If it begins with a digit,
5300 GDB will attempt to attach it as a process, and if no such process
5301 is found, will then attempt to open it as a corefile.
5303 * Changes in ARM configurations.
5305 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5306 configuration is fully multi-arch.
5308 * New native configurations
5310 ARM NetBSD arm*-*-netbsd*
5311 x86 OpenBSD i[3456]86-*-openbsd*
5312 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5313 Sparc64 running FreeBSD sparc64-*-freebsd*
5317 Sanyo XStormy16 xstormy16-elf
5319 * OBSOLETE configurations and files
5321 Configurations that have been declared obsolete in this release have
5322 been commented out. Unless there is activity to revive these
5323 configurations, the next release of GDB will have their sources
5324 permanently REMOVED.
5326 AMD 29k family via UDI a29k-amd-udi, udi29k
5327 A29K VxWorks a29k-*-vxworks
5328 AMD 29000 embedded, using EBMON a29k-none-none
5329 AMD 29000 embedded with COFF a29k-none-coff
5330 AMD 29000 embedded with a.out a29k-none-aout
5332 testsuite/gdb.hp/gdb.threads-hp/ directory
5334 * REMOVED configurations and files
5336 TI TMS320C80 tic80-*-*
5338 PowerPC Solaris powerpcle-*-solaris*
5339 PowerPC Windows NT powerpcle-*-cygwin32
5340 PowerPC Netware powerpc-*-netware*
5341 Harris/CXUX m88k m88*-harris-cxux*
5342 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5343 ns32k-utek-sysv* ns32k-utek-*
5344 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5345 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5346 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5347 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5348 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5350 * Changes to command line processing
5352 The new `--args' feature can be used to specify command-line arguments
5353 for the inferior from gdb's command line.
5355 * Changes to key bindings
5357 There is a new `operate-and-get-next' function bound to `C-o'.
5359 *** Changes in GDB 5.1.1
5361 Fix compile problem on DJGPP.
5363 Fix a problem with floating-point registers on the i386 being
5366 Fix to stop GDB crashing on .debug_str debug info.
5368 Numerous documentation fixes.
5370 Numerous testsuite fixes.
5372 *** Changes in GDB 5.1:
5374 * New native configurations
5376 Alpha FreeBSD alpha*-*-freebsd*
5377 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5378 MIPS GNU/Linux mips*-*-linux*
5379 MIPS SGI Irix 6.x mips*-sgi-irix6*
5380 ia64 AIX ia64-*-aix*
5381 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5385 Motorola 68HC11 and 68HC12 m68hc11-elf
5387 UltraSparc running GNU/Linux sparc64-*-linux*
5389 * OBSOLETE configurations and files
5391 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5392 Harris/CXUX m88k m88*-harris-cxux*
5393 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5394 ns32k-utek-sysv* ns32k-utek-*
5395 TI TMS320C80 tic80-*-*
5397 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5398 PowerPC Solaris powerpcle-*-solaris*
5399 PowerPC Windows NT powerpcle-*-cygwin32
5400 PowerPC Netware powerpc-*-netware*
5401 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5402 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5403 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5404 Apple Macintosh (MPW) host N/A
5406 stuff.c (Program to stuff files into a specially prepared space in kdb)
5407 kdb-start.c (Main loop for the standalone kernel debugger)
5409 Configurations that have been declared obsolete in this release have
5410 been commented out. Unless there is activity to revive these
5411 configurations, the next release of GDB will have their sources
5412 permanently REMOVED.
5414 * REMOVED configurations and files
5416 Altos 3068 m68*-altos-*
5417 Convex c1-*-*, c2-*-*
5419 ARM RISCix arm-*-* (as host)
5423 * GDB has been converted to ISO C.
5425 GDB's source code has been converted to ISO C. In particular, the
5426 sources are fully protoized, and rely on standard headers being
5431 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5433 * The MI enabled by default.
5435 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5436 revised and enabled by default. Packages which use GDB as a debugging
5437 engine behind a UI or another front end are encouraged to switch to
5438 using the GDB/MI interface, instead of the old annotations interface
5439 which is now deprecated.
5441 * Support for debugging Pascal programs.
5443 GDB now includes support for debugging Pascal programs. The following
5444 main features are supported:
5446 - Pascal-specific data types such as sets;
5448 - automatic recognition of Pascal sources based on file-name
5451 - Pascal-style display of data types, variables, and functions;
5453 - a Pascal expression parser.
5455 However, some important features are not yet supported.
5457 - Pascal string operations are not supported at all;
5459 - there are some problems with boolean types;
5461 - Pascal type hexadecimal constants are not supported
5462 because they conflict with the internal variables format;
5464 - support for Pascal objects and classes is not full yet;
5466 - unlike Pascal, GDB is case-sensitive for symbol names.
5468 * Changes in completion.
5470 Commands such as `shell', `run' and `set args', which pass arguments
5471 to inferior programs, now complete on file names, similar to what
5472 users expect at the shell prompt.
5474 Commands which accept locations, such as `disassemble', `print',
5475 `breakpoint', `until', etc. now complete on filenames as well as
5476 program symbols. Thus, if you type "break foob TAB", and the source
5477 files linked into the programs include `foobar.c', that file name will
5478 be one of the candidates for completion. However, file names are not
5479 considered for completion after you typed a colon that delimits a file
5480 name from a name of a function in that file, as in "break foo.c:bar".
5482 `set demangle-style' completes on available demangling styles.
5484 * New platform-independent commands:
5486 It is now possible to define a post-hook for a command as well as a
5487 hook that runs before the command. For more details, see the
5488 documentation of `hookpost' in the GDB manual.
5490 * Changes in GNU/Linux native debugging.
5492 Support for debugging multi-threaded programs has been completely
5493 revised for all platforms except m68k and sparc. You can now debug as
5494 many threads as your system allows you to have.
5496 Attach/detach is supported for multi-threaded programs.
5498 Support for SSE registers was added for x86. This doesn't work for
5499 multi-threaded programs though.
5501 * Changes in MIPS configurations.
5503 Multi-arch support is enabled for all MIPS configurations.
5505 GDB can now be built as native debugger on SGI Irix 6.x systems for
5506 debugging n32 executables. (Debugging 64-bit executables is not yet
5509 * Unified support for hardware watchpoints in all x86 configurations.
5511 Most (if not all) native x86 configurations support hardware-assisted
5512 breakpoints and watchpoints in a unified manner. This support
5513 implements debug register sharing between watchpoints, which allows to
5514 put a virtually infinite number of watchpoints on the same address,
5515 and also supports watching regions up to 16 bytes with several debug
5518 The new maintenance command `maintenance show-debug-regs' toggles
5519 debugging print-outs in functions that insert, remove, and test
5520 watchpoints and hardware breakpoints.
5522 * Changes in the DJGPP native configuration.
5524 New command ``info dos sysinfo'' displays assorted information about
5525 the CPU, OS, memory, and DPMI server.
5527 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5528 display information about segment descriptors stored in GDT, LDT, and
5531 New commands ``info dos pde'' and ``info dos pte'' display entries
5532 from Page Directory and Page Tables (for now works with CWSDPMI only).
5533 New command ``info dos address-pte'' displays the Page Table entry for
5534 a given linear address.
5536 GDB can now pass command lines longer than 126 characters to the
5537 program being debugged (requires an update to the libdbg.a library
5538 which is part of the DJGPP development kit).
5540 DWARF2 debug info is now supported.
5542 It is now possible to `step' and `next' through calls to `longjmp'.
5544 * Changes in documentation.
5546 All GDB documentation was converted to GFDL, the GNU Free
5547 Documentation License.
5549 Tracepoints-related commands are now fully documented in the GDB
5552 TUI, the Text-mode User Interface, is now documented in the manual.
5554 Tracepoints-related commands are now fully documented in the GDB
5557 The "GDB Internals" manual now has an index. It also includes
5558 documentation of `ui_out' functions, GDB coding standards, x86
5559 hardware watchpoints, and memory region attributes.
5561 * GDB's version number moved to ``version.in''
5563 The Makefile variable VERSION has been replaced by the file
5564 ``version.in''. People creating GDB distributions should update the
5565 contents of this file.
5569 GUD support is now a standard part of the EMACS distribution.
5571 *** Changes in GDB 5.0:
5573 * Improved support for debugging FP programs on x86 targets
5575 Unified and much-improved support for debugging floating-point
5576 programs on all x86 targets. In particular, ``info float'' now
5577 displays the FP registers in the same format on all x86 targets, with
5578 greater level of detail.
5580 * Improvements and bugfixes in hardware-assisted watchpoints
5582 It is now possible to watch array elements, struct members, and
5583 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5584 on x86 targets no longer erroneously trigger when the address is
5587 * Improvements in the native DJGPP version of GDB
5589 The distribution now includes all the scripts and auxiliary files
5590 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5591 machines ``out of the box''.
5593 The DJGPP version can now debug programs that use signals. It is
5594 possible to catch signals that happened in the debuggee, deliver
5595 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5596 would kill the program being debugged.) Programs that hook hardware
5597 interrupts (keyboard, timer, etc.) can also be debugged.
5599 It is now possible to debug DJGPP programs that redirect their
5600 standard handles or switch them to raw (as opposed to cooked) mode, or
5601 even close them. The command ``run < foo > bar'' works as expected,
5602 and ``info terminal'' reports useful information about the debuggee's
5603 terminal, including raw/cooked mode, redirection, etc.
5605 The DJGPP version now uses termios functions for console I/O, which
5606 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5609 DOS-style file names with drive letters are now fully supported by
5612 It is now possible to debug DJGPP programs that switch their working
5613 directory. It is also possible to rerun the debuggee any number of
5614 times without restarting GDB; thus, you can use the same setup,
5615 breakpoints, etc. for many debugging sessions.
5617 * New native configurations
5619 ARM GNU/Linux arm*-*-linux*
5620 PowerPC GNU/Linux powerpc-*-linux*
5624 Motorola MCore mcore-*-*
5625 x86 VxWorks i[3456]86-*-vxworks*
5626 PowerPC VxWorks powerpc-*-vxworks*
5627 TI TMS320C80 tic80-*-*
5629 * OBSOLETE configurations
5631 Altos 3068 m68*-altos-*
5632 Convex c1-*-*, c2-*-*
5634 ARM RISCix arm-*-* (as host)
5637 Configurations that have been declared obsolete will be commented out,
5638 but the code will be left in place. If there is no activity to revive
5639 these configurations before the next release of GDB, the sources will
5640 be permanently REMOVED.
5642 * Gould support removed
5644 Support for the Gould PowerNode and NP1 has been removed.
5646 * New features for SVR4
5648 On SVR4 native platforms (such as Solaris), if you attach to a process
5649 without first loading a symbol file, GDB will now attempt to locate and
5650 load symbols from the running process's executable file.
5652 * Many C++ enhancements
5654 C++ support has been greatly improved. Overload resolution now works properly
5655 in almost all cases. RTTI support is on the way.
5657 * Remote targets can connect to a sub-program
5659 A popen(3) style serial-device has been added. This device starts a
5660 sub-process (such as a stand-alone simulator) and then communicates
5661 with that. The sub-program to run is specified using the syntax
5662 ``|<program> <args>'' vis:
5664 (gdb) set remotedebug 1
5665 (gdb) target extended-remote |mn10300-elf-sim program-args
5667 * MIPS 64 remote protocol
5669 A long standing bug in the mips64 remote protocol where by GDB
5670 expected certain 32 bit registers (ex SR) to be transfered as 32
5671 instead of 64 bits has been fixed.
5673 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5674 added to provide backward compatibility with older versions of GDB.
5676 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5678 The command ``set remotebinarydownload'' command has been replaced by
5679 ``set remote X-packet''. Other commands in ``set remote'' family
5680 include ``set remote P-packet''.
5682 * Breakpoint commands accept ranges.
5684 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5685 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5686 ``tracepoint passcount'' also accepts a range of tracepoints.
5688 * ``apropos'' command added.
5690 The ``apropos'' command searches through command names and
5691 documentation strings, printing out matches, making it much easier to
5692 try to find a command that does what you are looking for.
5696 A new machine oriented interface (MI) has been added to GDB. This
5697 interface is designed for debug environments running GDB as a separate
5698 process. This is part of the long term libGDB project. See the
5699 "GDB/MI" chapter of the GDB manual for further information. It can be
5700 enabled by configuring with:
5702 .../configure --enable-gdbmi
5704 *** Changes in GDB-4.18:
5706 * New native configurations
5708 HP-UX 10.20 hppa*-*-hpux10.20
5709 HP-UX 11.x hppa*-*-hpux11.0*
5710 M68K GNU/Linux m68*-*-linux*
5714 Fujitsu FR30 fr30-*-elf*
5715 Intel StrongARM strongarm-*-*
5716 Mitsubishi D30V d30v-*-*
5718 * OBSOLETE configurations
5720 Gould PowerNode, NP1 np1-*-*, pn-*-*
5722 Configurations that have been declared obsolete will be commented out,
5723 but the code will be left in place. If there is no activity to revive
5724 these configurations before the next release of GDB, the sources will
5725 be permanently REMOVED.
5729 As a compatibility experiment, GDB's source files buildsym.h and
5730 buildsym.c have been converted to pure standard C, no longer
5731 containing any K&R compatibility code. We believe that all systems in
5732 use today either come with a standard C compiler, or have a GCC port
5733 available. If this is not true, please report the affected
5734 configuration to bug-gdb@gnu.org immediately. See the README file for
5735 information about getting a standard C compiler if you don't have one
5740 GDB now uses readline 2.2.
5742 * set extension-language
5744 You can now control the mapping between filename extensions and source
5745 languages by using the `set extension-language' command. For instance,
5746 you can ask GDB to treat .c files as C++ by saying
5747 set extension-language .c c++
5748 The command `info extensions' lists all of the recognized extensions
5749 and their associated languages.
5751 * Setting processor type for PowerPC and RS/6000
5753 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5754 you can use the `set processor' command to specify what variant of the
5755 PowerPC family you are debugging. The command
5759 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5760 following PowerPC and RS6000 variants:
5762 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5763 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5765 403GC IBM PowerPC 403GC
5766 505 Motorola PowerPC 505
5767 860 Motorola PowerPC 860 or 850
5768 601 Motorola PowerPC 601
5769 602 Motorola PowerPC 602
5770 603 Motorola/IBM PowerPC 603 or 603e
5771 604 Motorola PowerPC 604 or 604e
5772 750 Motorola/IBM PowerPC 750 or 750
5774 At the moment, this command just tells GDB what to name the
5775 special-purpose processor registers. Since almost all the affected
5776 registers are inaccessible to user-level programs, this command is
5777 only useful for remote debugging in its present form.
5781 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5782 more extensive support for HP-UX. Added features include shared
5783 library support, kernel threads and hardware watchpoints for 11.00,
5784 support for HP's ANSI C and C++ compilers, and a compatibility mode
5785 for xdb and dbx commands.
5789 HP's donation includes the new concept of catchpoints, which is a
5790 generalization of the old catch command. On HP-UX, it is now possible
5791 to catch exec, fork, and vfork, as well as library loading.
5793 This means that the existing catch command has changed; its first
5794 argument now specifies the type of catch to be set up. See the
5795 output of "help catch" for a list of catchpoint types.
5797 * Debugging across forks
5799 On HP-UX, you can choose which process to debug when a fork() happens
5804 HP has donated a curses-based terminal user interface (TUI). To get
5805 it, build with --enable-tui. Although this can be enabled for any
5806 configuration, at present it only works for native HP debugging.
5808 * GDB remote protocol additions
5810 A new protocol packet 'X' that writes binary data is now available.
5811 Default behavior is to try 'X', then drop back to 'M' if the stub
5812 fails to respond. The settable variable `remotebinarydownload'
5813 allows explicit control over the use of 'X'.
5815 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5816 full 64-bit address. The command
5818 set remoteaddresssize 32
5820 can be used to revert to the old behaviour. For existing remote stubs
5821 the change should not be noticed, as the additional address information
5824 In order to assist in debugging stubs, you may use the maintenance
5825 command `packet' to send any text string to the stub. For instance,
5827 maint packet heythere
5829 sends the packet "$heythere#<checksum>". Note that it is very easy to
5830 disrupt a debugging session by sending the wrong packet at the wrong
5833 The compare-sections command allows you to compare section data on the
5834 target to what is in the executable file without uploading or
5835 downloading, by comparing CRC checksums.
5837 * Tracing can collect general expressions
5839 You may now collect general expressions at tracepoints. This requires
5840 further additions to the target-side stub; see tracepoint.c and
5841 doc/agentexpr.texi for further details.
5843 * mask-address variable for Mips
5845 For Mips targets, you may control the zeroing of the upper 32 bits of
5846 a 64-bit address by entering `set mask-address on'. This is mainly
5847 of interest to users of embedded R4xxx and R5xxx processors.
5849 * Higher serial baud rates
5851 GDB's serial code now allows you to specify baud rates 57600, 115200,
5852 230400, and 460800 baud. (Note that your host system may not be able
5853 to achieve all of these rates.)
5857 The i960 configuration now includes an initial implementation of a
5858 builtin simulator, contributed by Jim Wilson.
5861 *** Changes in GDB-4.17:
5863 * New native configurations
5865 Alpha GNU/Linux alpha*-*-linux*
5866 Unixware 2.x i[3456]86-unixware2*
5867 Irix 6.x mips*-sgi-irix6*
5868 PowerPC GNU/Linux powerpc-*-linux*
5869 PowerPC Solaris powerpcle-*-solaris*
5870 Sparc GNU/Linux sparc-*-linux*
5871 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5875 Argonaut Risc Chip (ARC) arc-*-*
5876 Hitachi H8/300S h8300*-*-*
5877 Matsushita MN10200 w/simulator mn10200-*-*
5878 Matsushita MN10300 w/simulator mn10300-*-*
5879 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5880 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5881 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5882 Mitsubishi D10V w/simulator d10v-*-*
5883 Mitsubishi M32R/D w/simulator m32r-*-elf*
5884 Tsqware Sparclet sparclet-*-*
5885 NEC V850 w/simulator v850-*-*
5887 * New debugging protocols
5889 ARM with RDI protocol arm*-*-*
5890 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5891 DDB and LSI variants of PMON protocol mips*-*-*
5892 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5893 PowerPC with SDS protocol powerpc{,le}-*-eabi
5894 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5898 All configurations can now understand and use the DWARF 2 debugging
5899 format. The choice is automatic, if the symbol file contains DWARF 2
5904 GDB now includes basic Java language support. This support is
5905 only useful with Java compilers that produce native machine code.
5907 * solib-absolute-prefix and solib-search-path
5909 For SunOS and SVR4 shared libraries, you may now set the prefix for
5910 loading absolute shared library symbol files, and the search path for
5911 locating non-absolute shared library symbol files.
5913 * Live range splitting
5915 GDB can now effectively debug code for which GCC has performed live
5916 range splitting as part of its optimization. See gdb/doc/LRS for
5917 more details on the expected format of the stabs information.
5921 GDB's support for the GNU Hurd, including thread debugging, has been
5922 updated to work with current versions of the Hurd.
5926 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5927 instruction set. ARM GDB automatically detects when Thumb
5928 instructions are in use, and adjusts disassembly and backtracing
5933 GDB's MIPS target configurations now handle the MIP16 16-bit
5938 GDB now includes support for overlays; if an executable has been
5939 linked such that multiple sections are based at the same address, GDB
5940 will decide which section to use for symbolic info. You can choose to
5941 control the decision manually, using overlay commands, or implement
5942 additional target-side support and use "overlay load-target" to bring
5943 in the overlay mapping. Do "help overlay" for more detail.
5947 The command "info symbol <address>" displays information about
5948 the symbol at the specified address.
5952 The standard remote protocol now includes an extension that allows
5953 asynchronous collection and display of trace data. This requires
5954 extensive support in the target-side debugging stub. Tracing mode
5955 includes a new interaction mode in GDB and new commands: see the
5956 file tracepoint.c for more details.
5960 Configurations for embedded MIPS now include a simulator contributed
5961 by Cygnus Solutions. The simulator supports the instruction sets
5962 of most MIPS variants.
5966 Sparc configurations may now include the ERC32 simulator contributed
5967 by the European Space Agency. The simulator is not built into
5968 Sparc targets by default; configure with --enable-sim to include it.
5972 For target configurations that may include multiple variants of a
5973 basic architecture (such as MIPS and SH), you may now set the
5974 architecture explicitly. "set arch" sets, "info arch" lists
5975 the possible architectures.
5977 *** Changes in GDB-4.16:
5979 * New native configurations
5981 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5982 M68K NetBSD m68k-*-netbsd*
5983 PowerPC AIX 4.x powerpc-*-aix*
5984 PowerPC MacOS powerpc-*-macos*
5985 PowerPC Windows NT powerpcle-*-cygwin32
5986 RS/6000 AIX 4.x rs6000-*-aix4*
5990 ARM with RDP protocol arm-*-*
5991 I960 with MON960 i960-*-coff
5992 MIPS VxWorks mips*-*-vxworks*
5993 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5994 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5996 Matra Sparclet sparclet-*-*
6000 The powerpc-eabi configuration now includes the PSIM simulator,
6001 contributed by Andrew Cagney, with assistance from Mike Meissner.
6002 PSIM is a very elaborate model of the PowerPC, including not only
6003 basic instruction set execution, but also details of execution unit
6004 performance and I/O hardware. See sim/ppc/README for more details.
6008 GDB now works with Solaris 2.5.
6010 * Windows 95/NT native
6012 GDB will now work as a native debugger on Windows 95 and Windows NT.
6013 To build it from source, you must use the "gnu-win32" environment,
6014 which uses a DLL to emulate enough of Unix to run the GNU tools.
6015 Further information, binaries, and sources are available at
6016 ftp.cygnus.com, under pub/gnu-win32.
6018 * dont-repeat command
6020 If a user-defined command includes the command `dont-repeat', then the
6021 command will not be repeated if the user just types return. This is
6022 useful if the command is time-consuming to run, so that accidental
6023 extra keystrokes don't run the same command many times.
6025 * Send break instead of ^C
6027 The standard remote protocol now includes an option to send a break
6028 rather than a ^C to the target in order to interrupt it. By default,
6029 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6031 * Remote protocol timeout
6033 The standard remote protocol includes a new variable `remotetimeout'
6034 that allows you to set the number of seconds before GDB gives up trying
6035 to read from the target. The default value is 2.
6037 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6039 By default GDB will automatically keep track of objects as they are
6040 loaded and unloaded by the dynamic linker. By using the command `set
6041 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6042 when shared library events occur, thus allowing you to set breakpoints
6043 in shared libraries which are explicitly loaded by the inferior.
6045 Note this feature does not work on hpux8. On hpux9 you must link
6046 /usr/lib/end.o into your program. This feature should work
6047 automatically on hpux10.
6049 * Irix 5.x hardware watchpoint support
6051 Irix 5 configurations now support the use of hardware watchpoints.
6053 * Mips protocol "SYN garbage limit"
6055 When debugging a Mips target using the `target mips' protocol, you
6056 may set the number of characters that GDB will ignore by setting
6057 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6058 every character. The default value is 1050.
6060 * Recording and replaying remote debug sessions
6062 If you set `remotelogfile' to the name of a file, gdb will write to it
6063 a recording of a remote debug session. This recording may then be
6064 replayed back to gdb using "gdbreplay". See gdbserver/README for
6065 details. This is useful when you have a problem with GDB while doing
6066 remote debugging; you can make a recording of the session and send it
6067 to someone else, who can then recreate the problem.
6069 * Speedups for remote debugging
6071 GDB includes speedups for downloading and stepping MIPS systems using
6072 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6073 and more efficient S-record downloading.
6075 * Memory use reductions and statistics collection
6077 GDB now uses less memory and reports statistics about memory usage.
6078 Try the `maint print statistics' command, for example.
6080 *** Changes in GDB-4.15:
6082 * Psymtabs for XCOFF
6084 The symbol reader for AIX GDB now uses partial symbol tables. This
6085 can greatly improve startup time, especially for large executables.
6087 * Remote targets use caching
6089 Remote targets now use a data cache to speed up communication with the
6090 remote side. The data cache could lead to incorrect results because
6091 it doesn't know about volatile variables, thus making it impossible to
6092 debug targets which use memory mapped I/O devices. `set remotecache
6093 off' turns the the data cache off.
6095 * Remote targets may have threads
6097 The standard remote protocol now includes support for multiple threads
6098 in the target system, using new protocol commands 'H' and 'T'. See
6099 gdb/remote.c for details.
6103 If GDB is configured with `--enable-netrom', then it will include
6104 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6105 acts as though it is a bank of ROM on the target board, but you can
6106 write into it over the network. GDB's support consists only of
6107 support for fast loading into the emulated ROM; to debug, you must use
6108 another protocol, such as standard remote protocol. The usual
6109 sequence is something like
6111 target nrom <netrom-hostname>
6113 target remote <netrom-hostname>:1235
6117 GDB now includes support for the Apple Macintosh, as a host only. It
6118 may be run as either an MPW tool or as a standalone application, and
6119 it can debug through the serial port. All the usual GDB commands are
6120 available, but to the target command, you must supply "serial" as the
6121 device type instead of "/dev/ttyXX". See mpw-README in the main
6122 directory for more information on how to build. The MPW configuration
6123 scripts */mpw-config.in support only a few targets, and only the
6124 mips-idt-ecoff target has been tested.
6128 GDB configuration now uses autoconf. This is not user-visible,
6129 but does simplify configuration and building.
6133 GDB now supports hpux10.
6135 *** Changes in GDB-4.14:
6137 * New native configurations
6139 x86 FreeBSD i[345]86-*-freebsd
6140 x86 NetBSD i[345]86-*-netbsd
6141 NS32k NetBSD ns32k-*-netbsd
6142 Sparc NetBSD sparc-*-netbsd
6146 A29K VxWorks a29k-*-vxworks
6147 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6148 CPU32 EST-300 emulator m68*-*-est*
6149 PowerPC ELF powerpc-*-elf
6152 * Alpha OSF/1 support for procfs
6154 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6155 possible to attach to running processes. As the mounting of the /proc
6156 filesystem is optional on the Alpha, GDB automatically determines
6157 the availability of /proc during startup. This can lead to problems
6158 if /proc is unmounted after GDB has been started.
6160 * Arguments to user-defined commands
6162 User commands may accept up to 10 arguments separated by whitespace.
6163 Arguments are accessed within the user command via $arg0..$arg9. A
6166 print $arg0 + $arg1 + $arg2
6168 To execute the command use:
6171 Defines the command "adder" which prints the sum of its three arguments.
6172 Note the arguments are text substitutions, so they may reference variables,
6173 use complex expressions, or even perform inferior function calls.
6175 * New `if' and `while' commands
6177 This makes it possible to write more sophisticated user-defined
6178 commands. Both commands take a single argument, which is the
6179 expression to evaluate, and must be followed by the commands to
6180 execute, one per line, if the expression is nonzero, the list being
6181 terminated by the word `end'. The `if' command list may include an
6182 `else' word, which causes the following commands to be executed only
6183 if the expression is zero.
6185 * Fortran source language mode
6187 GDB now includes partial support for Fortran 77. It will recognize
6188 Fortran programs and can evaluate a subset of Fortran expressions, but
6189 variables and functions may not be handled correctly. GDB will work
6190 with G77, but does not yet know much about symbols emitted by other
6193 * Better HPUX support
6195 Most debugging facilities now work on dynamic executables for HPPAs
6196 running hpux9 or later. You can attach to running dynamically linked
6197 processes, but by default the dynamic libraries will be read-only, so
6198 for instance you won't be able to put breakpoints in them. To change
6199 that behavior do the following before running the program:
6205 This will cause the libraries to be mapped private and read-write.
6206 To revert to the normal behavior, do this:
6212 You cannot set breakpoints or examine data in the library until after
6213 the library is loaded if the function/data symbols do not have
6216 GDB can now also read debug symbols produced by the HP C compiler on
6217 HPPAs (sorry, no C++, Fortran or 68k support).
6219 * Target byte order now dynamically selectable
6221 You can choose which byte order to use with a target system, via the
6222 commands "set endian big" and "set endian little", and you can see the
6223 current setting by using "show endian". You can also give the command
6224 "set endian auto", in which case GDB will use the byte order
6225 associated with the executable. Currently, only embedded MIPS
6226 configurations support dynamic selection of target byte order.
6228 * New DOS host serial code
6230 This version uses DPMI interrupts to handle buffered I/O, so you
6231 no longer need to run asynctsr when debugging boards connected to
6234 *** Changes in GDB-4.13:
6236 * New "complete" command
6238 This lists all the possible completions for the rest of the line, if it
6239 were to be given as a command itself. This is intended for use by emacs.
6241 * Trailing space optional in prompt
6243 "set prompt" no longer adds a space for you after the prompt you set. This
6244 allows you to set a prompt which ends in a space or one that does not.
6246 * Breakpoint hit counts
6248 "info break" now displays a count of the number of times the breakpoint
6249 has been hit. This is especially useful in conjunction with "ignore"; you
6250 can ignore a large number of breakpoint hits, look at the breakpoint info
6251 to see how many times the breakpoint was hit, then run again, ignoring one
6252 less than that number, and this will get you quickly to the last hit of
6255 * Ability to stop printing at NULL character
6257 "set print null-stop" will cause GDB to stop printing the characters of
6258 an array when the first NULL is encountered. This is useful when large
6259 arrays actually contain only short strings.
6261 * Shared library breakpoints
6263 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6264 breakpoints in shared libraries before the executable is run.
6266 * Hardware watchpoints
6268 There is a new hardware breakpoint for the watch command for sparclite
6269 targets. See gdb/sparclite/hw_breakpoint.note.
6271 Hardware watchpoints are also now supported under GNU/Linux.
6275 Annotations have been added. These are for use with graphical interfaces,
6276 and are still experimental. Currently only gdba.el uses these.
6278 * Improved Irix 5 support
6280 GDB now works properly with Irix 5.2.
6282 * Improved HPPA support
6284 GDB now works properly with the latest GCC and GAS.
6286 * New native configurations
6288 Sequent PTX4 i[34]86-sequent-ptx4
6289 HPPA running OSF/1 hppa*-*-osf*
6290 Atari TT running SVR4 m68*-*-sysv4*
6291 RS/6000 LynxOS rs6000-*-lynxos*
6295 OS/9000 i[34]86-*-os9k
6296 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6299 * Hitachi SH7000 and E7000-PC ICE support
6301 There is now support for communicating with the Hitachi E7000-PC ICE.
6302 This is available automatically when GDB is configured for the SH.
6306 As usual, a variety of small fixes and improvements, both generic
6307 and configuration-specific. See the ChangeLog for more detail.
6309 *** Changes in GDB-4.12:
6311 * Irix 5 is now supported
6315 GDB-4.12 on the HPPA has a number of changes which make it unable
6316 to debug the output from the currently released versions of GCC and
6317 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6318 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6319 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6322 *** Changes in GDB-4.11:
6324 * User visible changes:
6328 The "set remotedebug" option is now consistent between the mips remote
6329 target, remote targets using the gdb-specific protocol, UDI (AMD's
6330 debug protocol for the 29k) and the 88k bug monitor. It is now an
6331 integer specifying a debug level (normally 0 or 1, but 2 means more
6332 debugging info for the mips target).
6334 * DEC Alpha native support
6336 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6337 debug info, but GDB works fairly well with the DEC compiler and should
6338 work with a future GCC release. See the README file for a few
6339 Alpha-specific notes.
6341 * Preliminary thread implementation
6343 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6345 * LynxOS native and target support for 386
6347 This release has been hosted on LynxOS 2.2, and also can be configured
6348 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6351 * Improvements in C++ mangling/demangling.
6353 This release has much better g++ debugging, specifically in name
6354 mangling/demangling, virtual function calls, print virtual table,
6355 call methods, ...etc.
6357 *** Changes in GDB-4.10:
6359 * User visible changes:
6361 Remote debugging using the GDB-specific (`target remote') protocol now
6362 supports the `load' command. This is only useful if you have some
6363 other way of getting the stub to the target system, and you can put it
6364 somewhere in memory where it won't get clobbered by the download.
6366 Filename completion now works.
6368 When run under emacs mode, the "info line" command now causes the
6369 arrow to point to the line specified. Also, "info line" prints
6370 addresses in symbolic form (as well as hex).
6372 All vxworks based targets now support a user settable option, called
6373 vxworks-timeout. This option represents the number of seconds gdb
6374 should wait for responses to rpc's. You might want to use this if
6375 your vxworks target is, perhaps, a slow software simulator or happens
6376 to be on the far side of a thin network line.
6380 This release contains support for using a DEC alpha as a GDB host for
6381 cross debugging. Native alpha debugging is not supported yet.
6384 *** Changes in GDB-4.9:
6388 This is the first GDB release which is accompanied by a matching testsuite.
6389 The testsuite requires installation of dejagnu, which should be available
6390 via ftp from most sites that carry GNU software.
6394 'Cfront' style demangling has had its name changed to 'ARM' style, to
6395 emphasize that it was written from the specifications in the C++ Annotated
6396 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6397 disclaimers, it still generated too much confusion with users attempting to
6398 use gdb with AT&T cfront.
6402 GDB now uses a standard remote interface to a simulator library.
6403 So far, the library contains simulators for the Zilog Z8001/2, the
6404 Hitachi H8/300, H8/500 and Super-H.
6406 * New targets supported
6408 H8/300 simulator h8300-hitachi-hms or h8300hms
6409 H8/500 simulator h8500-hitachi-hms or h8500hms
6410 SH simulator sh-hitachi-hms or sh
6411 Z8000 simulator z8k-zilog-none or z8ksim
6412 IDT MIPS board over serial line mips-idt-ecoff
6414 Cross-debugging to GO32 targets is supported. It requires a custom
6415 version of the i386-stub.c module which is integrated with the
6416 GO32 memory extender.
6418 * New remote protocols
6420 MIPS remote debugging protocol.
6422 * New source languages supported
6424 This version includes preliminary support for Chill, a Pascal like language
6425 used by telecommunications companies. Chill support is also being integrated
6426 into the GNU compiler, but we don't know when it will be publically available.
6429 *** Changes in GDB-4.8:
6431 * HP Precision Architecture supported
6433 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6434 version of this support was available as a set of patches from the
6435 University of Utah. GDB does not support debugging of programs
6436 compiled with the HP compiler, because HP will not document their file
6437 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6438 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6440 Many problems in the preliminary version have been fixed.
6442 * Faster and better demangling
6444 We have improved template demangling and fixed numerous bugs in the GNU style
6445 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6446 character types (wchar_t) are now supported. Demangling of each symbol is now
6447 only done once, and is cached when the symbol table for a file is read in.
6448 This results in a small increase in memory usage for C programs, a moderate
6449 increase in memory usage for C++ programs, and a fantastic speedup in
6452 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6453 from the specifications in the Annotated Reference Manual, which AT&T's
6454 compiler does not actually implement.
6456 * G++ multiple inheritance compiler problem
6458 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6459 inheritance lattices was reworked to properly discover ambiguities. We
6460 recently found an example which causes this new algorithm to fail in a
6461 very subtle way, producing bad debug information for those classes.
6462 The file 'gcc.patch' (in this directory) can be applied to gcc to
6463 circumvent the problem. A future GCC release will contain a complete
6466 The previous G++ debug info problem (mentioned below for the gdb-4.7
6467 release) is fixed in gcc version 2.3.2.
6469 * Improved configure script
6471 The `configure' script will now attempt to guess your system type if
6472 you don't supply a host system type. The old scheme of supplying a
6473 host system triplet is preferable over using this. All the magic is
6474 done in the new `config.guess' script. Examine it for details.
6476 We have also brought our configure script much more in line with the FSF's
6477 version. It now supports the --with-xxx options. In particular,
6478 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6479 The resulting GDB will not be able to read arbitrary object file formats --
6480 only the format ``expected'' to be used on the configured target system.
6481 We hope to make this the default in a future release.
6483 * Documentation improvements
6485 There's new internal documentation on how to modify GDB, and how to
6486 produce clean changes to the code. We implore people to read it
6487 before submitting changes.
6489 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6490 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6491 `info' files are also provided. To build `info' files from scratch,
6492 you will need the latest `makeinfo' release, which will be available in
6493 a future texinfo-X.Y release.
6495 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6496 We're not sure exactly which versions have this problem, but it has
6497 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6498 or better. If that isn't possible, there is a patch in
6499 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6500 around this problem.
6504 GDB now supports array constants that can be used in expressions typed in by
6505 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6506 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6509 The new directory `gdb/sparclite' contains a program that demonstrates
6510 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6512 * New native hosts supported
6514 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6515 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6517 * New targets supported
6519 AMD 29k family via UDI a29k-amd-udi or udi29k
6521 * New file formats supported
6523 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6524 HPUX core files, and SCO 3.2v2 core files.
6528 Attaching to processes now works again; thanks for the many bug reports.
6530 We have also stomped on a bunch of core dumps caused by
6531 printf_filtered("%s") problems.
6533 We eliminated a copyright problem on the rpc and ptrace header files
6534 for VxWorks, which was discovered at the last minute during the 4.7
6535 release. You should now be able to build a VxWorks GDB.
6537 You can now interrupt gdb while an attached process is running. This
6538 will cause the attached process to stop, and give control back to GDB.
6540 We fixed problems caused by using too many file descriptors
6541 for reading symbols from object files and libraries. This was
6542 especially a problem for programs that used many (~100) shared
6545 The `step' command now only enters a subroutine if there is line number
6546 information for the subroutine. Otherwise it acts like the `next'
6547 command. Previously, `step' would enter subroutines if there was
6548 any debugging information about the routine. This avoids problems
6549 when using `cc -g1' on MIPS machines.
6551 * Internal improvements
6553 GDB's internal interfaces have been improved to make it easier to support
6554 debugging of multiple languages in the future.
6556 GDB now uses a common structure for symbol information internally.
6557 Minimal symbols (derived from linkage symbols in object files), partial
6558 symbols (from a quick scan of debug information), and full symbols
6559 contain a common subset of information, making it easier to write
6560 shared code that handles any of them.
6562 * New command line options
6564 We now accept --silent as an alias for --quiet.
6568 The memory-mapped-malloc library is now licensed under the GNU Library
6569 General Public License.
6571 *** Changes in GDB-4.7:
6573 * Host/native/target split
6575 GDB has had some major internal surgery to untangle the support for
6576 hosts and remote targets. Now, when you configure GDB for a remote
6577 target, it will no longer load in all of the support for debugging
6578 local programs on the host. When fully completed and tested, this will
6579 ensure that arbitrary host/target combinations are possible.
6581 The primary conceptual shift is to separate the non-portable code in
6582 GDB into three categories. Host specific code is required any time GDB
6583 is compiled on that host, regardless of the target. Target specific
6584 code relates to the peculiarities of the target, but can be compiled on
6585 any host. Native specific code is everything else: it can only be
6586 built when the host and target are the same system. Child process
6587 handling and core file support are two common `native' examples.
6589 GDB's use of /proc for controlling Unix child processes is now cleaner.
6590 It has been split out into a single module under the `target_ops' vector,
6591 plus two native-dependent functions for each system that uses /proc.
6593 * New hosts supported
6595 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6596 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6597 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6599 * New targets supported
6601 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6602 68030 and CPU32 m68030-*-*, m68332-*-*
6604 * New native hosts supported
6606 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6607 (386bsd is not well tested yet)
6608 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6610 * New file formats supported
6612 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6613 supports reading of `a.out.adobe' object files, which are an a.out
6614 format extended with minimal information about multiple sections.
6618 `show copying' is the same as the old `info copying'.
6619 `show warranty' is the same as `info warrantee'.
6620 These were renamed for consistency. The old commands continue to work.
6622 `info handle' is a new alias for `info signals'.
6624 You can now define pre-command hooks, which attach arbitrary command
6625 scripts to any command. The commands in the hook will be executed
6626 prior to the user's command. You can also create a hook which will be
6627 executed whenever the program stops. See gdb.texinfo.
6631 We now deal with Cfront style name mangling, and can even extract type
6632 info from mangled symbols. GDB can automatically figure out which
6633 symbol mangling style your C++ compiler uses.
6635 Calling of methods and virtual functions has been improved as well.
6639 The crash that occured when debugging Sun Ansi-C compiled binaries is
6640 fixed. This was due to mishandling of the extra N_SO stabs output
6643 We also finally got Ultrix 4.2 running in house, and fixed core file
6644 support, with help from a dozen people on the net.
6646 John M. Farrell discovered that the reason that single-stepping was so
6647 slow on all of the Mips based platforms (primarily SGI and DEC) was
6648 that we were trying to demangle and lookup a symbol used for internal
6649 purposes on every instruction that was being stepped through. Changing
6650 the name of that symbol so that it couldn't be mistaken for a C++
6651 mangled symbol sped things up a great deal.
6653 Rich Pixley sped up symbol lookups in general by getting much smarter
6654 about when C++ symbol mangling is necessary. This should make symbol
6655 completion (TAB on the command line) much faster. It's not as fast as
6656 we'd like, but it's significantly faster than gdb-4.6.
6660 A new user controllable variable 'call_scratch_address' can
6661 specify the location of a scratch area to be used when GDB
6662 calls a function in the target. This is necessary because the
6663 usual method of putting the scratch area on the stack does not work
6664 in systems that have separate instruction and data spaces.
6666 We integrated changes to support the 29k UDI (Universal Debugger
6667 Interface), but discovered at the last minute that we didn't have all
6668 of the appropriate copyright paperwork. We are working with AMD to
6669 resolve this, and hope to have it available soon.
6673 We have sped up the remote serial line protocol, especially for targets
6674 with lots of registers. It now supports a new `expedited status' ('T')
6675 message which can be used in place of the existing 'S' status message.
6676 This allows the remote stub to send only the registers that GDB
6677 needs to make a quick decision about single-stepping or conditional
6678 breakpoints, eliminating the need to fetch the entire register set for
6679 each instruction being stepped through.
6681 The GDB remote serial protocol now implements a write-through cache for
6682 registers, only re-reading the registers if the target has run.
6684 There is also a new remote serial stub for SPARC processors. You can
6685 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6686 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6687 processor with a serial port.
6691 Configure.in files have become much easier to read and modify. A new
6692 `table driven' format makes it more obvious what configurations are
6693 supported, and what files each one uses.
6697 There is a new opcodes library which will eventually contain all of the
6698 disassembly routines and opcode tables. At present, it only contains
6699 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6700 disassembler (binutils/objdump) to share these routines.
6702 The libiberty library is now copylefted under the GNU Library General
6703 Public License. This allows more liberal use, and was done so libg++
6704 can use it. This makes no difference to GDB, since the Library License
6705 grants all the rights from the General Public License.
6709 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6710 reference to the stabs symbol info used by the debugger. It is (as far
6711 as we know) the only published document on this fascinating topic. We
6712 encourage you to read it, compare it to the stabs information on your
6713 system, and send improvements on the document in general (to
6714 bug-gdb@prep.ai.mit.edu).
6716 And, of course, many bugs have been fixed.
6719 *** Changes in GDB-4.6:
6721 * Better support for C++ function names
6723 GDB now accepts as input the "demangled form" of C++ overloaded function
6724 names and member function names, and can do command completion on such names
6725 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6726 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6727 Make use of command completion, it is your friend.
6729 GDB also now accepts a variety of C++ mangled symbol formats. They are
6730 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6731 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6732 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6733 for the list of formats.
6735 * G++ symbol mangling problem
6737 Recent versions of gcc have a bug in how they emit debugging information for
6738 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6739 directory) can be applied to gcc to fix the problem. Alternatively, if you
6740 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6741 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6742 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6745 * New 'maintenance' command
6747 All of the commands related to hacking GDB internals have been moved out of
6748 the main command set, and now live behind the 'maintenance' command. This
6749 can also be abbreviated as 'mt'. The following changes were made:
6751 dump-me -> maintenance dump-me
6752 info all-breakpoints -> maintenance info breakpoints
6753 printmsyms -> maintenance print msyms
6754 printobjfiles -> maintenance print objfiles
6755 printpsyms -> maintenance print psymbols
6756 printsyms -> maintenance print symbols
6758 The following commands are new:
6760 maintenance demangle Call internal GDB demangler routine to
6761 demangle a C++ link name and prints the result.
6762 maintenance print type Print a type chain for a given symbol
6764 * Change to .gdbinit file processing
6766 We now read the $HOME/.gdbinit file before processing the argv arguments
6767 (e.g. reading symbol files or core files). This allows global parameters to
6768 be set, which will apply during the symbol reading. The ./.gdbinit is still
6769 read after argv processing.
6771 * New hosts supported
6773 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6775 GNU/Linux support i386-unknown-linux or linux
6777 We are also including code to support the HP/PA running BSD and HPUX. This
6778 is almost guaranteed not to work, as we didn't have time to test or build it
6779 for this release. We are including it so that the more adventurous (or
6780 masochistic) of you can play with it. We also had major problems with the
6781 fact that the compiler that we got from HP doesn't support the -g option.
6784 * New targets supported
6786 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6788 * More smarts about finding #include files
6790 GDB now remembers the compilation directory for all include files, and for
6791 all files from which C is generated (like yacc and lex sources). This
6792 greatly improves GDB's ability to find yacc/lex sources, and include files,
6793 especially if you are debugging your program from a directory different from
6794 the one that contains your sources.
6796 We also fixed a bug which caused difficulty with listing and setting
6797 breakpoints in include files which contain C code. (In the past, you had to
6798 try twice in order to list an include file that you hadn't looked at before.)
6800 * Interesting infernals change
6802 GDB now deals with arbitrary numbers of sections, where the symbols for each
6803 section must be relocated relative to that section's landing place in the
6804 target's address space. This work was needed to support ELF with embedded
6805 stabs used by Solaris-2.0.
6807 * Bug fixes (of course!)
6809 There have been loads of fixes for the following things:
6810 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6811 i960, stabs, DOS(GO32), procfs, etc...
6813 See the ChangeLog for details.
6815 *** Changes in GDB-4.5:
6817 * New machines supported (host and target)
6819 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6821 SGI Irix-4.x mips-sgi-irix4 or iris4
6823 * New malloc package
6825 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6826 Mmalloc is capable of handling mutiple heaps of memory. It is also
6827 capable of saving a heap to a file, and then mapping it back in later.
6828 This can be used to greatly speedup the startup of GDB by using a
6829 pre-parsed symbol table which lives in a mmalloc managed heap. For
6830 more details, please read mmalloc/mmalloc.texi.
6834 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6835 'help info proc' for details.
6837 * MIPS ecoff symbol table format
6839 The code that reads MIPS symbol table format is now supported on all hosts.
6840 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6843 * File name changes for MS-DOS
6845 Many files in the config directories have been renamed to make it easier to
6846 support GDB on MS-DOSe systems (which have very restrictive file name
6847 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6848 environment) is close to working but has some remaining problems. Note
6849 that debugging of DOS programs is not supported, due to limitations
6850 in the ``operating system'', but it can be used to host cross-debugging.
6852 * Cross byte order fixes
6854 Many fixes have been made to support cross debugging of Sparc and MIPS
6855 targets from hosts whose byte order differs.
6857 * New -mapped and -readnow options
6859 If memory-mapped files are available on your system through the 'mmap'
6860 system call, you can use the -mapped option on the `file' or
6861 `symbol-file' commands to cause GDB to write the symbols from your
6862 program into a reusable file. If the program you are debugging is
6863 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6864 Future GDB debugging sessions will notice the presence of this file,
6865 and will quickly map in symbol information from it, rather than reading
6866 the symbol table from the executable program. Using the '-mapped'
6867 option in a GDB `file' or `symbol-file' command has the same effect as
6868 starting GDB with the '-mapped' command-line option.
6870 You can cause GDB to read the entire symbol table immediately by using
6871 the '-readnow' option with any of the commands that load symbol table
6872 information (or on the GDB command line). This makes the command
6873 slower, but makes future operations faster.
6875 The -mapped and -readnow options are typically combined in order to
6876 build a `fred.syms' file that contains complete symbol information.
6877 A simple GDB invocation to do nothing but build a `.syms' file for future
6880 gdb -batch -nx -mapped -readnow programname
6882 The `.syms' file is specific to the host machine on which GDB is run.
6883 It holds an exact image of GDB's internal symbol table. It cannot be
6884 shared across multiple host platforms.
6886 * longjmp() handling
6888 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6889 siglongjmp() without losing control. This feature has not yet been ported to
6890 all systems. It currently works on many 386 platforms, all MIPS-based
6891 platforms (SGI, DECstation, etc), and Sun3/4.
6895 Preliminary work has been put in to support the new Solaris OS from Sun. At
6896 this time, it can control and debug processes, but it is not capable of
6901 As always, many many bug fixes. The major areas were with g++, and mipsread.
6902 People using the MIPS-based platforms should experience fewer mysterious
6903 crashes and trashed symbol tables.
6905 *** Changes in GDB-4.4:
6907 * New machines supported (host and target)
6909 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6911 BSD Reno on Vax vax-dec-bsd
6912 Ultrix on Vax vax-dec-ultrix
6914 * New machines supported (target)
6916 AMD 29000 embedded, using EBMON a29k-none-none
6920 GDB continues to improve its handling of C++. `References' work better.
6921 The demangler has also been improved, and now deals with symbols mangled as
6922 per the Annotated C++ Reference Guide.
6924 GDB also now handles `stabs' symbol information embedded in MIPS
6925 `ecoff' symbol tables. Since the ecoff format was not easily
6926 extensible to handle new languages such as C++, this appeared to be a
6927 good way to put C++ debugging info into MIPS binaries. This option
6928 will be supported in the GNU C compiler, version 2, when it is
6931 * New features for SVR4
6933 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6934 shared libraries. Debugging dynamically linked programs should present
6935 only minor differences from debugging statically linked programs.
6937 The `info proc' command will print out information about any process
6938 on an SVR4 system (including the one you are debugging). At the moment,
6939 it prints the address mappings of the process.
6941 If you bring up GDB on another SVR4 system, please send mail to
6942 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6944 * Better dynamic linking support in SunOS
6946 Reading symbols from shared libraries which contain debugging symbols
6947 now works properly. However, there remain issues such as automatic
6948 skipping of `transfer vector' code during function calls, which
6949 make it harder to debug code in a shared library, than to debug the
6950 same code linked statically.
6954 GDB is now using the latest `getopt' routines from the FSF. This
6955 version accepts the -- prefix for options with long names. GDB will
6956 continue to accept the old forms (-option and +option) as well.
6957 Various single letter abbreviations for options have been explicity
6958 added to the option table so that they won't get overshadowed in the
6959 future by other options that begin with the same letter.
6963 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6964 Many assorted bugs have been handled. Many more remain to be handled.
6965 See the various ChangeLog files (primarily in gdb and bfd) for details.
6968 *** Changes in GDB-4.3:
6970 * New machines supported (host and target)
6972 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6973 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6974 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6976 * Almost SCO Unix support
6978 We had hoped to support:
6979 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6980 (except for core file support), but we discovered very late in the release
6981 that it has problems with process groups that render gdb unusable. Sorry
6982 about that. I encourage people to fix it and post the fixes.
6984 * Preliminary ELF and DWARF support
6986 GDB can read ELF object files on System V Release 4, and can handle
6987 debugging records for C, in DWARF format, in ELF files. This support
6988 is preliminary. If you bring up GDB on another SVR4 system, please
6989 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6994 GDB now uses the latest `readline' library. One user-visible change
6995 is that two tabs will list possible command completions, which previously
6996 required typing M-? (meta-question mark, or ESC ?).
7000 The `stepi' bug that many of you noticed has been squashed.
7001 Many bugs in C++ have been handled. Many more remain to be handled.
7002 See the various ChangeLog files (primarily in gdb and bfd) for details.
7004 * State of the MIPS world (in case you wondered):
7006 GDB can understand the symbol tables emitted by the compilers
7007 supplied by most vendors of MIPS-based machines, including DEC. These
7008 symbol tables are in a format that essentially nobody else uses.
7010 Some versions of gcc come with an assembler post-processor called
7011 mips-tfile. This program is required if you want to do source-level
7012 debugging of gcc-compiled programs. I believe FSF does not ship
7013 mips-tfile with gcc version 1, but it will eventually come with gcc
7016 Debugging of g++ output remains a problem. g++ version 1.xx does not
7017 really support it at all. (If you're lucky, you should be able to get
7018 line numbers and stack traces to work, but no parameters or local
7019 variables.) With some work it should be possible to improve the
7022 When gcc version 2 is released, you will have somewhat better luck.
7023 However, even then you will get confusing results for inheritance and
7026 We will eventually provide full debugging of g++ output on
7027 DECstations. This will probably involve some kind of stabs-in-ecoff
7028 encapulation, but the details have not been worked out yet.
7031 *** Changes in GDB-4.2:
7033 * Improved configuration
7035 Only one copy of `configure' exists now, and it is not self-modifying.
7036 Porting BFD is simpler.
7040 The `step' and `next' commands now only stop at the first instruction
7041 of a source line. This prevents the multiple stops that used to occur
7042 in switch statements, for-loops, etc. `Step' continues to stop if a
7043 function that has debugging information is called within the line.
7047 Lots of small bugs fixed. More remain.
7049 * New host supported (not target)
7051 Intel 386 PC clone running Mach i386-none-mach
7054 *** Changes in GDB-4.1:
7056 * Multiple source language support
7058 GDB now has internal scaffolding to handle several source languages.
7059 It determines the type of each source file from its filename extension,
7060 and will switch expression parsing and number formatting to match the
7061 language of the function in the currently selected stack frame.
7062 You can also specifically set the language to be used, with
7063 `set language c' or `set language modula-2'.
7067 GDB now has preliminary support for the GNU Modula-2 compiler,
7068 currently under development at the State University of New York at
7069 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7070 continue through the fall of 1991 and into 1992.
7072 Other Modula-2 compilers are currently not supported, and attempting to
7073 debug programs compiled with them will likely result in an error as the
7074 symbol table is read. Feel free to work on it, though!
7076 There are hooks in GDB for strict type checking and range checking,
7077 in the `Modula-2 philosophy', but they do not currently work.
7081 GDB can now write to executable and core files (e.g. patch
7082 a variable's value). You must turn this switch on, specify
7083 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7084 by assigning a new value to a variable. Modifications take
7087 * Automatic SunOS shared library reading
7089 When you run your program, GDB automatically determines where its
7090 shared libraries (if any) have been loaded, and reads their symbols.
7091 The `share' command is no longer needed. This also works when
7092 examining core files.
7096 You can specify the number of lines that the `list' command shows.
7099 * New machines supported (host and target)
7101 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7102 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7103 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7105 * New hosts supported (not targets)
7107 IBM RT/PC: romp-ibm-aix or rtpc
7109 * New targets supported (not hosts)
7111 AMD 29000 embedded with COFF a29k-none-coff
7112 AMD 29000 embedded with a.out a29k-none-aout
7113 Ultracomputer remote kernel debug a29k-nyu-kern
7115 * New remote interfaces
7121 *** Changes in GDB-4.0:
7125 Wide output is wrapped at good places to make the output more readable.
7127 Gdb now supports cross-debugging from a host machine of one type to a
7128 target machine of another type. Communication with the target system
7129 is over serial lines. The ``target'' command handles connecting to the
7130 remote system; the ``load'' command will download a program into the
7131 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7132 also supports debugging of realtime processes running under VxWorks,
7133 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7134 stub on the target system.
7136 New CPUs supported include the AMD 29000 and Intel 960.
7138 GDB now reads object files and symbol tables via a ``binary file''
7139 library, which allows a single copy of GDB to debug programs of multiple
7140 object file types such as a.out and coff.
7142 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7143 refcard.dvi and refcard.ps are available to format it).
7146 * Control-Variable user interface simplified
7148 All variables that control the operation of the debugger can be set
7149 by the ``set'' command, and displayed by the ``show'' command.
7151 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7152 ``Show prompt'' produces the response:
7153 Gdb's prompt is new-gdb=>.
7155 What follows are the NEW set commands. The command ``help set'' will
7156 print a complete list of old and new set commands. ``help set FOO''
7157 will give a longer description of the variable FOO. ``show'' will show
7158 all of the variable descriptions and their current settings.
7160 confirm on/off: Enables warning questions for operations that are
7161 hard to recover from, e.g. rerunning the program while
7162 it is already running. Default is ON.
7164 editing on/off: Enables EMACS style command line editing
7165 of input. Previous lines can be recalled with
7166 control-P, the current line can be edited with control-B,
7167 you can search for commands with control-R, etc.
7170 history filename NAME: NAME is where the gdb command history
7171 will be stored. The default is .gdb_history,
7172 or the value of the environment variable
7175 history size N: The size, in commands, of the command history. The
7176 default is 256, or the value of the environment variable
7179 history save on/off: If this value is set to ON, the history file will
7180 be saved after exiting gdb. If set to OFF, the
7181 file will not be saved. The default is OFF.
7183 history expansion on/off: If this value is set to ON, then csh-like
7184 history expansion will be performed on
7185 command line input. The default is OFF.
7187 radix N: Sets the default radix for input and output. It can be set
7188 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7189 in the current radix, so "set radix 10" is always a no-op.
7191 height N: This integer value is the number of lines on a page. Default
7192 is 24, the current `stty rows'' setting, or the ``li#''
7193 setting from the termcap entry matching the environment
7196 width N: This integer value is the number of characters on a line.
7197 Default is 80, the current `stty cols'' setting, or the ``co#''
7198 setting from the termcap entry matching the environment
7201 Note: ``set screensize'' is obsolete. Use ``set height'' and
7202 ``set width'' instead.
7204 print address on/off: Print memory addresses in various command displays,
7205 such as stack traces and structure values. Gdb looks
7206 more ``symbolic'' if you turn this off; it looks more
7207 ``machine level'' with it on. Default is ON.
7209 print array on/off: Prettyprint arrays. New convenient format! Default
7212 print demangle on/off: Print C++ symbols in "source" form if on,
7215 print asm-demangle on/off: Same, for assembler level printouts
7218 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7221 * Support for Epoch Environment.
7223 The epoch environment is a version of Emacs v18 with windowing. One
7224 new command, ``inspect'', is identical to ``print'', except that if you
7225 are running in the epoch environment, the value is printed in its own
7229 * Support for Shared Libraries
7231 GDB can now debug programs and core files that use SunOS shared libraries.
7232 Symbols from a shared library cannot be referenced
7233 before the shared library has been linked with the program (this
7234 happens after you type ``run'' and before the function main() is entered).
7235 At any time after this linking (including when examining core files
7236 from dynamically linked programs), gdb reads the symbols from each
7237 shared library when you type the ``sharedlibrary'' command.
7238 It can be abbreviated ``share''.
7240 sharedlibrary REGEXP: Load shared object library symbols for files
7241 matching a unix regular expression. No argument
7242 indicates to load symbols for all shared libraries.
7244 info sharedlibrary: Status of loaded shared libraries.
7249 A watchpoint stops execution of a program whenever the value of an
7250 expression changes. Checking for this slows down execution
7251 tremendously whenever you are in the scope of the expression, but is
7252 quite useful for catching tough ``bit-spreader'' or pointer misuse
7253 problems. Some machines such as the 386 have hardware for doing this
7254 more quickly, and future versions of gdb will use this hardware.
7256 watch EXP: Set a watchpoint (breakpoint) for an expression.
7258 info watchpoints: Information about your watchpoints.
7260 delete N: Deletes watchpoint number N (same as breakpoints).
7261 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7262 enable N: Re-enables watchpoint number N (same as breakpoints).
7265 * C++ multiple inheritance
7267 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7270 * C++ exception handling
7272 Gdb now supports limited C++ exception handling. Besides the existing
7273 ability to breakpoint on an exception handler, gdb can breakpoint on
7274 the raising of an exception (before the stack is peeled back to the
7277 catch FOO: If there is a FOO exception handler in the dynamic scope,
7278 set a breakpoint to catch exceptions which may be raised there.
7279 Multiple exceptions (``catch foo bar baz'') may be caught.
7281 info catch: Lists all exceptions which may be caught in the
7282 current stack frame.
7285 * Minor command changes
7287 The command ``call func (arg, arg, ...)'' now acts like the print
7288 command, except it does not print or save a value if the function's result
7289 is void. This is similar to dbx usage.
7291 The ``up'' and ``down'' commands now always print the frame they end up
7292 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7293 frames without printing.
7295 * New directory command
7297 'dir' now adds directories to the FRONT of the source search path.
7298 The path starts off empty. Source files that contain debug information
7299 about the directory in which they were compiled can be found even
7300 with an empty path; Sun CC and GCC include this information. If GDB can't
7301 find your source file in the current directory, type "dir .".
7303 * Configuring GDB for compilation
7305 For normal use, type ``./configure host''. See README or gdb.texinfo
7308 GDB now handles cross debugging. If you are remotely debugging between
7309 two different machines, type ``./configure host -target=targ''.
7310 Host is the machine where GDB will run; targ is the machine
7311 where the program that you are debugging will run.