1 What has changed in GDB?
2 (Organized release by release)
6 * GDB and GDBserver now support access to additional registers on
7 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
10 * GDB now has experimental support for the compilation and injection of
11 C++ source code into the inferior. This beta release does not include
12 support for several language features, such as templates, constructors,
15 This feature requires GCC 7.1 or higher built with libcp1.so
18 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
19 can be passed using the '[ADDRESS]:PORT' notation, or the regular
20 'ADDRESS:PORT' method.
22 * DWARF index cache: GDB can now automatically save indices of DWARF
23 symbols on disk to speed up further loading of the same binaries.
25 * Ada task switching is now supported on aarch64-elf targets when
26 debugging a program using the Ravenscar Profile. For more information,
27 see the "Tasking Support when using the Ravenscar Profile" section
28 in the GDB user manual.
30 * GDB in batch mode now exits with status 1 if the last command to be
33 * The RISC-V target now supports target descriptions.
35 * System call catchpoints now support system call aliases on FreeBSD.
36 When the ABI of a system call changes in FreeBSD, this is
37 implemented by leaving a compatibility system call using the old ABI
38 at the existing number and allocating a new system call number for
39 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
40 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
41 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
42 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
43 so that a system call catchpoint for the 'kevent' system call will
44 catch invocations of both the 'kevent' and 'freebsd11_kevent'
45 binaries. This ensures that 'kevent' system calls are caught for
46 binaries using either the old or new ABIs.
48 * Terminal styling is now available for the CLI and the TUI. GNU
49 Source Highlight can additionally be used to provide styling of
50 source code snippets. See the "set style" commands, below, for more
53 * Removed support for old demangling styles arm, edg, gnu, hp and
59 GNU/Linux/OpenRISC or1k*-*-linux*
63 set debug compile-cplus-types
64 show debug compile-cplus-types
65 Control the display of debug output about type conversion in the
66 C++ compile feature. Commands have no effect while compiliong
71 Control whether debug output about files/functions skipping is
74 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
75 Apply a command to some frames.
76 FLAG arguments allow to control what output to produce and how to handle
77 errors raised when applying COMMAND to a frame.
80 Apply a command to all threads (ignoring errors and empty output).
81 Shortcut for 'thread apply all -s COMMAND'.
84 Apply a command to all frames (ignoring errors and empty output).
85 Shortcut for 'frame apply all -s COMMAND'.
88 Apply a command to all frames of all threads (ignoring errors and empty
90 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
92 maint set dwarf unwinders (on|off)
93 maint show dwarf unwinders
94 Control whether DWARF unwinders can be used.
97 Display a list of open files for a process.
101 Changes to the "frame", "select-frame", and "info frame" CLI commands.
102 These commands all now take a frame specification which
103 is either a frame level, or one of the keywords 'level', 'address',
104 'function', or 'view' followed by a parameter. Selecting a frame by
105 address, or viewing a frame outside the current backtrace now
106 requires the use of a keyword. Selecting a frame by level is
107 unchanged. The MI comment "-stack-select-frame" is unchanged.
109 target remote FILENAME
110 target extended-remote FILENAME
111 If FILENAME is a Unix domain socket, GDB will attempt to connect
112 to this socket instead of opening FILENAME as a character device.
114 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
115 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
116 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
117 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
118 These commands can now print only the searched entities
119 matching the provided regexp(s), giving a condition
120 on the entity names or entity types. The flag -q disables
121 printing headers or informations messages.
127 These commands now determine the syntax for the shown entities
128 according to the language chosen by `set language'. In particular,
129 `set language auto' means to automatically choose the language of
132 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
133 The 'thread apply' command accepts new FLAG arguments.
134 FLAG arguments allow to control what output to produce and how to handle
135 errors raised when applying COMMAND to a thread.
137 set tui tab-width NCHARS
138 show tui tab-width NCHARS
139 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
141 set style enabled [on|off]
143 Enable or disable terminal styling. Styling is enabled by default
144 on most hosts, but disabled by default when in batch mode.
146 set style filename foreground COLOR
147 set style filename background COLOR
148 set style filename intensity VALUE
149 Control the styling of file names.
151 set style function foreground COLOR
152 set style function background COLOR
153 set style function intensity VALUE
154 Control the styling of function names.
156 set style variable foreground COLOR
157 set style variable background COLOR
158 set style variable intensity VALUE
159 Control the styling of variable names.
161 set style address foreground COLOR
162 set style address background COLOR
163 set style address intensity VALUE
164 Control the styling of addresses.
168 ** The '-data-disassemble' MI command now accepts an '-a' option to
169 disassemble the whole function surrounding the given program
170 counter value or function name. Support for this feature can be
171 verified by using the "-list-features" command, which should
172 contain "data-disassemble-a-option".
174 ** Command responses and notifications that include a frame now include
175 the frame's architecture in a new "arch" attribute.
177 * New native configurations
179 GNU/Linux/RISC-V riscv*-*-linux*
180 FreeBSD/riscv riscv*-*-freebsd*
184 GNU/Linux/RISC-V riscv*-*-linux*
186 CSKY GNU/LINUX csky*-*-linux
187 FreeBSD/riscv riscv*-*-freebsd*
191 GDB no longer supports native debugging on versions of MS-Windows
196 ** GDB no longer supports Python versions less than 2.6.
198 ** The gdb.Inferior type has a new 'progspace' property, which is the program
199 space associated to that inferior.
201 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
202 of objfiles associated to that program space.
204 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
205 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
208 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
209 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
210 correct and did not work properly.
212 ** The gdb.Value type has a new constructor, which is used to construct a
213 gdb.Value from a Python buffer object and a gdb.Type.
219 Enable or disable the undefined behavior sanitizer. This is
220 disabled by default, but passing --enable-ubsan=yes or
221 --enable-ubsan=auto to configure will enable it. Enabling this can
222 cause a performance penalty. The undefined behavior sanitizer was
223 first introduced in GCC 4.9.
225 *** Changes in GDB 8.2
227 * The 'set disassembler-options' command now supports specifying options
230 * The 'symbol-file' command now accepts an '-o' option to add a relative
231 offset to all sections.
233 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
234 a relative offset to all sections, but it allows to override the load
235 address of individual sections using '-s'.
237 * The 'add-symbol-file' command no longer requires the second argument
238 (address of the text section).
240 * The endianness used with the 'set endian auto' mode in the absence of
241 an executable selected for debugging is now the last endianness chosen
242 either by one of the 'set endian big' and 'set endian little' commands
243 or by inferring from the last executable used, rather than the startup
246 * The pager now allows a "c" response, meaning to disable the pager
247 for the rest of the current command.
249 * The commands 'info variables/functions/types' now show the source line
250 numbers of symbol definitions when available.
252 * 'info proc' now works on running processes on FreeBSD systems and core
253 files created on FreeBSD systems.
255 * C expressions can now use _Alignof, and C++ expressions can now use
258 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
259 the vector length while the process is running.
265 Control display of debugging info regarding the FreeBSD native target.
267 set|show varsize-limit
268 This new setting allows the user to control the maximum size of Ada
269 objects being printed when those objects have a variable type,
270 instead of that maximum size being hardcoded to 65536 bytes.
272 set|show record btrace cpu
273 Controls the processor to be used for enabling errata workarounds for
276 maint check libthread-db
277 Run integrity checks on the current inferior's thread debugging
280 maint set check-libthread-db (on|off)
281 maint show check-libthread-db
282 Control whether to run integrity checks on inferior specific thread
283 debugging libraries as they are loaded. The default is not to
288 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
290 ** The commands attached to a breakpoint can be set by assigning to
291 the breakpoint's "commands" field.
293 ** gdb.execute can now execute multi-line gdb commands.
295 ** The new functions gdb.convenience_variable and
296 gdb.set_convenience_variable can be used to get and set the value
297 of convenience variables.
299 ** A gdb.Parameter will no longer print the "set" help text on an
300 ordinary "set"; instead by default a "set" will be silent unless
301 the get_set_string method returns a non-empty string.
305 RiscV ELF riscv*-*-elf
307 * Removed targets and native configurations
309 m88k running OpenBSD m88*-*-openbsd*
310 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
311 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
312 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
314 * Aarch64/Linux hardware watchpoints improvements
316 Hardware watchpoints on unaligned addresses are now properly
317 supported when running Linux kernel 4.10 or higher: read and access
318 watchpoints are no longer spuriously missed, and all watchpoints
319 lengths between 1 and 8 bytes are supported. On older kernels,
320 watchpoints set on unaligned addresses are no longer missed, with
321 the tradeoff that there is a possibility of false hits being
326 --enable-codesign=CERT
327 This can be used to invoke "codesign -s CERT" after building gdb.
328 This option is useful on macOS, where code signing is required for
329 gdb to work properly.
331 --disable-gdbcli has been removed
332 This is now silently accepted, but does nothing.
334 *** Changes in GDB 8.1
336 * GDB now supports dynamically creating arbitrary register groups specified
337 in XML target descriptions. This allows for finer grain grouping of
338 registers on systems with a large amount of registers.
340 * The 'ptype' command now accepts a '/o' flag, which prints the
341 offsets and sizes of fields in a struct, like the pahole(1) tool.
343 * New "--readnever" command line option instructs GDB to not read each
344 symbol file's symbolic debug information. This makes startup faster
345 but at the expense of not being able to perform symbolic debugging.
346 This option is intended for use cases where symbolic debugging will
347 not be used, e.g., when you only need to dump the debuggee's core.
349 * GDB now uses the GNU MPFR library, if available, to emulate target
350 floating-point arithmetic during expression evaluation when the target
351 uses different floating-point formats than the host. At least version
352 3.1 of GNU MPFR is required.
354 * GDB now supports access to the guarded-storage-control registers and the
355 software-based guarded-storage broadcast control registers on IBM z14.
357 * On Unix systems, GDB now supports transmitting environment variables
358 that are to be set or unset to GDBserver. These variables will
359 affect the environment to be passed to the remote inferior.
361 To inform GDB of environment variables that are to be transmitted to
362 GDBserver, use the "set environment" command. Only user set
363 environment variables are sent to GDBserver.
365 To inform GDB of environment variables that are to be unset before
366 the remote inferior is started by the GDBserver, use the "unset
367 environment" command.
369 * Completion improvements
371 ** GDB can now complete function parameters in linespecs and
372 explicit locations without quoting. When setting breakpoints,
373 quoting around functions names to help with TAB-completion is
374 generally no longer necessary. For example, this now completes
377 (gdb) b function(in[TAB]
378 (gdb) b function(int)
380 Related, GDB is no longer confused with completing functions in
381 C++ anonymous namespaces:
384 (gdb) b (anonymous namespace)::[TAB][TAB]
385 (anonymous namespace)::a_function()
386 (anonymous namespace)::b_function()
388 ** GDB now has much improved linespec and explicit locations TAB
389 completion support, that better understands what you're
390 completing and offers better suggestions. For example, GDB no
391 longer offers data symbols as possible completions when you're
392 setting a breakpoint.
394 ** GDB now TAB-completes label symbol names.
396 ** The "complete" command now mimics TAB completion accurately.
398 * New command line options (gcore)
401 Dump all memory mappings.
403 * Breakpoints on C++ functions are now set on all scopes by default
405 By default, breakpoints on functions/methods are now interpreted as
406 specifying all functions with the given name ignoring missing
407 leading scopes (namespaces and classes).
409 For example, assuming a C++ program with symbols named:
414 both commands "break func()" and "break B::func()" set a breakpoint
417 You can use the new flag "-qualified" to override this. This makes
418 GDB interpret the specified function name as a complete
419 fully-qualified name instead. For example, using the same C++
420 program, the "break -q B::func" command sets a breakpoint on
421 "B::func", only. A parameter has been added to the Python
422 gdb.Breakpoint constructor to achieve the same result when creating
423 a breakpoint from Python.
425 * Breakpoints on functions marked with C++ ABI tags
427 GDB can now set breakpoints on functions marked with C++ ABI tags
428 (e.g., [abi:cxx11]). See here for a description of ABI tags:
429 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
431 Functions with a C++11 abi tag are demangled/displayed like this:
433 function[abi:cxx11](int)
436 You can now set a breakpoint on such functions simply as if they had
439 (gdb) b function(int)
441 Or if you need to disambiguate between tags, like:
443 (gdb) b function[abi:other_tag](int)
445 Tab completion was adjusted accordingly as well.
449 ** New events gdb.new_inferior, gdb.inferior_deleted, and
450 gdb.new_thread are emitted. See the manual for further
451 description of these.
453 ** A new function, "gdb.rbreak" has been added to the Python API.
454 This function allows the setting of a large number of breakpoints
455 via a regex pattern in Python. See the manual for further details.
457 ** Python breakpoints can now accept explicit locations. See the
458 manual for a further description of this feature.
461 * New features in the GDB remote stub, GDBserver
463 ** GDBserver is now able to start inferior processes with a
464 specified initial working directory.
466 The user can set the desired working directory to be used from
467 GDB using the new "set cwd" command.
469 ** New "--selftest" command line option runs some GDBserver self
470 tests. These self tests are disabled in releases.
472 ** On Unix systems, GDBserver now does globbing expansion and variable
473 substitution in inferior command line arguments.
475 This is done by starting inferiors using a shell, like GDB does.
476 See "set startup-with-shell" in the user manual for how to disable
477 this from GDB when using "target extended-remote". When using
478 "target remote", you can disable the startup with shell by using the
479 new "--no-startup-with-shell" GDBserver command line option.
481 ** On Unix systems, GDBserver now supports receiving environment
482 variables that are to be set or unset from GDB. These variables
483 will affect the environment to be passed to the inferior.
485 * When catching an Ada exception raised with a message, GDB now prints
486 the message in the catchpoint hit notification. In GDB/MI mode, that
487 information is provided as an extra field named "exception-message"
488 in the *stopped notification.
490 * Trait objects can now be inspected When debugging Rust code. This
491 requires compiler support which will appear in Rust 1.24.
495 QEnvironmentHexEncoded
496 Inform GDBserver of an environment variable that is to be passed to
497 the inferior when starting it.
500 Inform GDBserver of an environment variable that is to be unset
501 before starting the remote inferior.
504 Inform GDBserver that the environment should be reset (i.e.,
505 user-set environment variables should be unset).
508 Indicates whether the inferior must be started with a shell or not.
511 Tell GDBserver that the inferior to be started should use a specific
514 * The "maintenance print c-tdesc" command now takes an optional
515 argument which is the file name of XML target description.
517 * The "maintenance selftest" command now takes an optional argument to
518 filter the tests to be run.
520 * The "enable", and "disable" commands now accept a range of
521 breakpoint locations, e.g. "enable 1.3-5".
526 Set and show the current working directory for the inferior.
529 Set and show compilation command used for compiling and injecting code
530 with the 'compile' commands.
532 set debug separate-debug-file
533 show debug separate-debug-file
534 Control the display of debug output about separate debug file search.
536 set dump-excluded-mappings
537 show dump-excluded-mappings
538 Control whether mappings marked with the VM_DONTDUMP flag should be
539 dumped when generating a core file.
542 List the registered selftests.
545 Start the debugged program stopping at the first instruction.
548 Control display of debugging messages related to OpenRISC targets.
550 set|show print type nested-type-limit
551 Set and show the limit of nesting level for nested types that the
552 type printer will show.
554 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
557 * Safer/improved support for debugging with no debug info
559 GDB no longer assumes functions with no debug information return
562 This means that GDB now refuses to call such functions unless you
563 tell it the function's type, by either casting the call to the
564 declared return type, or by casting the function to a function
565 pointer of the right type, and calling that:
567 (gdb) p getenv ("PATH")
568 'getenv' has unknown return type; cast the call to its declared return type
569 (gdb) p (char *) getenv ("PATH")
570 $1 = 0x7fffffffe "/usr/local/bin:/"...
571 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
572 $2 = 0x7fffffffe "/usr/local/bin:/"...
574 Similarly, GDB no longer assumes that global variables with no debug
575 info have type 'int', and refuses to print the variable's value
576 unless you tell it the variable's type:
579 'var' has unknown type; cast it to its declared type
583 * New native configurations
585 FreeBSD/aarch64 aarch64*-*-freebsd*
586 FreeBSD/arm arm*-*-freebsd*
590 FreeBSD/aarch64 aarch64*-*-freebsd*
591 FreeBSD/arm arm*-*-freebsd*
592 OpenRISC ELF or1k*-*-elf
594 * Removed targets and native configurations
596 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
598 *** Changes in GDB 8.0
600 * GDB now supports access to the PKU register on GNU/Linux. The register is
601 added by the Memory Protection Keys for Userspace feature which will be
602 available in future Intel CPUs.
604 * GDB now supports C++11 rvalue references.
608 ** New functions to start, stop and access a running btrace recording.
609 ** Rvalue references are now supported in gdb.Type.
611 * GDB now supports recording and replaying rdrand and rdseed Intel 64
614 * Building GDB and GDBserver now requires a C++11 compiler.
616 For example, GCC 4.8 or later.
618 It is no longer possible to build GDB or GDBserver with a C
619 compiler. The --disable-build-with-cxx configure option has been
622 * Building GDB and GDBserver now requires GNU make >= 3.81.
624 It is no longer supported to build GDB or GDBserver with another
625 implementation of the make program or an earlier version of GNU make.
627 * Native debugging on MS-Windows supports command-line redirection
629 Command-line arguments used for starting programs on MS-Windows can
630 now include redirection symbols supported by native Windows shells,
631 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
632 as "run", "start", and "set args", as well as the corresponding MI
635 * Support for thread names on MS-Windows.
637 GDB now catches and handles the special exception that programs
638 running on MS-Windows use to assign names to threads in the
641 * Support for Java programs compiled with gcj has been removed.
643 * User commands now accept an unlimited number of arguments.
644 Previously, only up to 10 was accepted.
646 * The "eval" command now expands user-defined command arguments.
648 This makes it easier to process a variable number of arguments:
653 eval "print $arg%d", $i
658 * Target descriptions can now describe registers for sparc32 and sparc64.
660 * GDB now supports DWARF version 5 (debug information format).
661 Its .debug_names index is not yet supported.
663 * New native configurations
665 FreeBSD/mips mips*-*-freebsd
669 Synopsys ARC arc*-*-elf32
670 FreeBSD/mips mips*-*-freebsd
672 * Removed targets and native configurations
674 Alpha running FreeBSD alpha*-*-freebsd*
675 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
680 Erases all the flash memory regions reported by the target.
682 maint print arc arc-instruction address
683 Print internal disassembler information about instruction at a given address.
687 set disassembler-options
688 show disassembler-options
689 Controls the passing of target specific information to the disassembler.
690 If it is necessary to specify more than one disassembler option then
691 multiple options can be placed together into a comma separated list.
692 The default value is the empty string. Currently, the only supported
693 targets are ARM, PowerPC and S/390.
698 Erases all the flash memory regions reported by the target. This is
699 equivalent to the CLI command flash-erase.
701 -file-list-shared-libraries
702 List the shared libraries in the program. This is
703 equivalent to the CLI command "info shared".
706 Catchpoints stopping the program when Ada exceptions are
707 handled. This is equivalent to the CLI command "catch handlers".
709 *** Changes in GDB 7.12
711 * GDB and GDBserver now build with a C++ compiler by default.
713 The --enable-build-with-cxx configure option is now enabled by
714 default. One must now explicitly configure with
715 --disable-build-with-cxx in order to build with a C compiler. This
716 option will be removed in a future release.
718 * GDBserver now supports recording btrace without maintaining an active
721 * GDB now supports a negative repeat count in the 'x' command to examine
722 memory backward from the given address. For example:
725 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
726 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
727 (gdb) x/-5i 0x0000000000400580
728 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
729 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
730 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
731 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
732 0x40057b <main(int, char**)+25>:
733 callq 0x400536 <Func1(int, char const*)>
735 * Fortran: Support structures with fields of dynamic types and
736 arrays of dynamic types.
738 * The symbol dumping maintenance commands have new syntax.
739 maint print symbols [-pc address] [--] [filename]
740 maint print symbols [-objfile objfile] [-source source] [--] [filename]
741 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
742 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
743 maint print msymbols [-objfile objfile] [--] [filename]
745 * GDB now supports multibit bitfields and enums in target register
748 * New Python-based convenience function $_as_string(val), which returns
749 the textual representation of a value. This function is especially
750 useful to obtain the text label of an enum value.
752 * Intel MPX bound violation handling.
754 Segmentation faults caused by a Intel MPX boundary violation
755 now display the kind of violation (upper or lower), the memory
756 address accessed and the memory bounds, along with the usual
757 signal received and code location.
761 Program received signal SIGSEGV, Segmentation fault
762 Upper bound violation while accessing address 0x7fffffffc3b3
763 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
764 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
766 * Rust language support.
767 GDB now supports debugging programs written in the Rust programming
768 language. See https://www.rust-lang.org/ for more information about
771 * Support for running interpreters on specified input/output devices
773 GDB now supports a new mechanism that allows frontends to provide
774 fully featured GDB console views, as a better alternative to
775 building such views on top of the "-interpreter-exec console"
776 command. See the new "new-ui" command below. With that command,
777 frontends can now start GDB in the traditional command-line mode
778 running in an embedded terminal emulator widget, and create a
779 separate MI interpreter running on a specified i/o device. In this
780 way, GDB handles line editing, history, tab completion, etc. in the
781 console all by itself, and the GUI uses the separate MI interpreter
782 for its own control and synchronization, invisible to the command
785 * The "catch syscall" command catches groups of related syscalls.
787 The "catch syscall" command now supports catching a group of related
788 syscalls using the 'group:' or 'g:' prefix.
793 skip -gfile file-glob-pattern
794 skip -function function
795 skip -rfunction regular-expression
796 A generalized form of the skip command, with new support for
797 glob-style file names and regular expressions for function names.
798 Additionally, a file spec and a function spec may now be combined.
800 maint info line-table REGEXP
801 Display the contents of GDB's internal line table data struture.
804 Run any GDB unit tests that were compiled in.
807 Start a new user interface instance running INTERP as interpreter,
808 using the TTY file for input/output.
812 ** gdb.Breakpoint objects have a new attribute "pending", which
813 indicates whether the breakpoint is pending.
814 ** Three new breakpoint-related events have been added:
815 gdb.breakpoint_created, gdb.breakpoint_modified, and
816 gdb.breakpoint_deleted.
819 Signal ("set") the given MS-Windows event object. This is used in
820 conjunction with the Windows JIT debugging (AeDebug) support, where
821 the OS suspends a crashing process until a debugger can attach to
822 it. Resuming the crashing process, in order to debug it, is done by
825 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
826 was added in GDBserver, including JIT compiling fast tracepoint's
827 conditional expression bytecode into native code.
829 * Support for various remote target protocols and ROM monitors has
832 target m32rsdi Remote M32R debugging over SDI
833 target mips MIPS remote debugging protocol
834 target pmon PMON ROM monitor
835 target ddb NEC's DDB variant of PMON for Vr4300
836 target rockhopper NEC RockHopper variant of PMON
837 target lsi LSI variant of PMO
839 * Support for tracepoints and fast tracepoints on powerpc-linux,
840 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
841 including JIT compiling fast tracepoint's conditional expression
842 bytecode into native code.
844 * MI async record =record-started now includes the method and format used for
845 recording. For example:
847 =record-started,thread-group="i1",method="btrace",format="bts"
849 * MI async record =thread-selected now includes the frame field. For example:
851 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
855 Andes NDS32 nds32*-*-elf
857 *** Changes in GDB 7.11
859 * GDB now supports debugging kernel-based threads on FreeBSD.
861 * Per-inferior thread numbers
863 Thread numbers are now per inferior instead of global. If you're
864 debugging multiple inferiors, GDB displays thread IDs using a
865 qualified INF_NUM.THR_NUM form. For example:
869 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
870 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
871 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
872 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
874 As consequence, thread numbers as visible in the $_thread
875 convenience variable and in Python's InferiorThread.num attribute
876 are no longer unique between inferiors.
878 GDB now maintains a second thread ID per thread, referred to as the
879 global thread ID, which is the new equivalent of thread numbers in
880 previous releases. See also $_gthread below.
882 For backwards compatibility, MI's thread IDs always refer to global
885 * Commands that accept thread IDs now accept the qualified
886 INF_NUM.THR_NUM form as well. For example:
889 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
892 * In commands that accept a list of thread IDs, you can now refer to
893 all threads of an inferior using a star wildcard. GDB accepts
894 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
895 refer to all threads of the current inferior. For example, "info
898 * You can use "info threads -gid" to display the global thread ID of
901 * The new convenience variable $_gthread holds the global number of
904 * The new convenience variable $_inferior holds the number of the
907 * GDB now displays the ID and name of the thread that hit a breakpoint
908 or received a signal, if your program is multi-threaded. For
911 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
912 Thread 1 "main" received signal SIGINT, Interrupt.
914 * Record btrace now supports non-stop mode.
916 * Support for tracepoints on aarch64-linux was added in GDBserver.
918 * The 'record instruction-history' command now indicates speculative execution
919 when using the Intel Processor Trace recording format.
921 * GDB now allows users to specify explicit locations, bypassing
922 the linespec parser. This feature is also available to GDB/MI
925 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
926 GDB now is able to debug both AArch64 applications and ARM applications
929 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
930 including JIT compiling fast tracepoint's conditional expression bytecode
933 * GDB now supports displaced stepping on AArch64 GNU/Linux.
935 * "info threads", "info inferiors", "info display", "info checkpoints"
936 and "maint info program-spaces" now list the corresponding items in
937 ascending ID order, for consistency with all other "info" commands.
939 * In Ada, the overloads selection menu has been enhanced to display the
940 parameter types and the return types for the matching overloaded subprograms.
944 maint set target-non-stop (on|off|auto)
945 maint show target-non-stop
946 Control whether GDB targets always operate in non-stop mode even if
947 "set non-stop" is "off". The default is "auto", meaning non-stop
948 mode is enabled if supported by the target.
950 maint set bfd-sharing
951 maint show bfd-sharing
952 Control the reuse of bfd objects.
956 Control display of debugging info regarding bfd caching.
960 Control display of debugging info regarding FreeBSD threads.
962 set remote multiprocess-extensions-packet
963 show remote multiprocess-extensions-packet
964 Set/show the use of the remote protocol multiprocess extensions.
966 set remote thread-events
967 show remote thread-events
968 Set/show the use of thread create/exit events.
970 set ada print-signatures on|off
971 show ada print-signatures"
972 Control whether parameter types and return types are displayed in overloads
973 selection menus. It is activaled (@code{on}) by default.
977 Controls the maximum size of memory, in bytes, that GDB will
978 allocate for value contents. Prevents incorrect programs from
979 causing GDB to allocate overly large buffers. Default is 64k.
981 * The "disassemble" command accepts a new modifier: /s.
982 It prints mixed source+disassembly like /m with two differences:
983 - disassembled instructions are now printed in program order, and
984 - and source for all relevant files is now printed.
985 The "/m" option is now considered deprecated: its "source-centric"
986 output hasn't proved useful in practice.
988 * The "record instruction-history" command accepts a new modifier: /s.
989 It behaves exactly like /m and prints mixed source+disassembly.
991 * The "set scheduler-locking" command supports a new mode "replay".
992 It behaves like "off" in record mode and like "on" in replay mode.
994 * Support for various ROM monitors has been removed:
996 target dbug dBUG ROM monitor for Motorola ColdFire
997 target picobug Motorola picobug monitor
998 target dink32 DINK32 ROM monitor for PowerPC
999 target m32r Renesas M32R/D ROM monitor
1000 target mon2000 mon2000 ROM monitor
1001 target ppcbug PPCBUG ROM monitor for PowerPC
1003 * Support for reading/writing memory and extracting values on architectures
1004 whose memory is addressable in units of any integral multiple of 8 bits.
1007 Allows to break when an Ada exception is handled.
1009 * New remote packets
1012 Indicates that an exec system call was executed.
1014 exec-events feature in qSupported
1015 The qSupported packet allows GDB to request support for exec
1016 events using the new 'gdbfeature' exec-event, and the qSupported
1017 response can contain the corresponding 'stubfeature'. Set and
1018 show commands can be used to display whether these features are enabled.
1021 Equivalent to interrupting with the ^C character, but works in
1024 thread created stop reason (T05 create:...)
1025 Indicates that the thread was just created and is stopped at entry.
1027 thread exit stop reply (w exitcode;tid)
1028 Indicates that the thread has terminated.
1031 Enables/disables thread create and exit event reporting. For
1032 example, this is used in non-stop mode when GDB stops a set of
1033 threads and synchronously waits for the their corresponding stop
1034 replies. Without exit events, if one of the threads exits, GDB
1035 would hang forever not knowing that it should no longer expect a
1036 stop for that same thread.
1039 Indicates that there are no resumed threads left in the target (all
1040 threads are stopped). The remote stub reports support for this stop
1041 reply to GDB's qSupported query.
1044 Enables/disables catching syscalls from the inferior process.
1045 The remote stub reports support for this packet to GDB's qSupported query.
1047 syscall_entry stop reason
1048 Indicates that a syscall was just called.
1050 syscall_return stop reason
1051 Indicates that a syscall just returned.
1053 * Extended-remote exec events
1055 ** GDB now has support for exec events on extended-remote Linux targets.
1056 For such targets with Linux kernels 2.5.46 and later, this enables
1057 follow-exec-mode and exec catchpoints.
1059 set remote exec-event-feature-packet
1060 show remote exec-event-feature-packet
1061 Set/show the use of the remote exec event feature.
1063 * Thread names in remote protocol
1065 The reply to qXfer:threads:read may now include a name attribute for each
1068 * Target remote mode fork and exec events
1070 ** GDB now has support for fork and exec events on target remote mode
1071 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1072 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1073 fork and exec catchpoints.
1075 * Remote syscall events
1077 ** GDB now has support for catch syscall on remote Linux targets,
1078 currently enabled on x86/x86_64 architectures.
1080 set remote catch-syscall-packet
1081 show remote catch-syscall-packet
1082 Set/show the use of the remote catch syscall feature.
1086 ** The -var-set-format command now accepts the zero-hexadecimal
1087 format. It outputs data in hexadecimal format with zero-padding on the
1092 ** gdb.InferiorThread objects have a new attribute "global_num",
1093 which refers to the thread's global thread ID. The existing
1094 "num" attribute now refers to the thread's per-inferior number.
1095 See "Per-inferior thread numbers" above.
1096 ** gdb.InferiorThread objects have a new attribute "inferior", which
1097 is the Inferior object the thread belongs to.
1099 *** Changes in GDB 7.10
1101 * Support for process record-replay and reverse debugging on aarch64*-linux*
1102 targets has been added. GDB now supports recording of A64 instruction set
1103 including advance SIMD instructions.
1105 * Support for Sun's version of the "stabs" debug file format has been removed.
1107 * GDB now honors the content of the file /proc/PID/coredump_filter
1108 (PID is the process ID) on GNU/Linux systems. This file can be used
1109 to specify the types of memory mappings that will be included in a
1110 corefile. For more information, please refer to the manual page of
1111 "core(5)". GDB also has a new command: "set use-coredump-filter
1112 on|off". It allows to set whether GDB will read the content of the
1113 /proc/PID/coredump_filter file when generating a corefile.
1115 * The "info os" command on GNU/Linux can now display information on
1117 "info os cpus" Listing of all cpus/cores on the system
1119 * GDB has two new commands: "set serial parity odd|even|none" and
1120 "show serial parity". These allows to set or show parity for the
1123 * The "info source" command now displays the producer string if it was
1124 present in the debug info. This typically includes the compiler version
1125 and may include things like its command line arguments.
1127 * The "info dll", an alias of the "info sharedlibrary" command,
1128 is now available on all platforms.
1130 * Directory names supplied to the "set sysroot" commands may be
1131 prefixed with "target:" to tell GDB to access shared libraries from
1132 the target system, be it local or remote. This replaces the prefix
1133 "remote:". The default sysroot has been changed from "" to
1134 "target:". "remote:" is automatically converted to "target:" for
1135 backward compatibility.
1137 * The system root specified by "set sysroot" will be prepended to the
1138 filename of the main executable (if reported to GDB as absolute by
1139 the operating system) when starting processes remotely, and when
1140 attaching to already-running local or remote processes.
1142 * GDB now supports automatic location and retrieval of executable
1143 files from remote targets. Remote debugging can now be initiated
1144 using only a "target remote" or "target extended-remote" command
1145 (no "set sysroot" or "file" commands are required). See "New remote
1148 * The "dump" command now supports verilog hex format.
1150 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1152 * On GNU/Linux, GDB and gdbserver are now able to access executable
1153 and shared library files without a "set sysroot" command when
1154 attaching to processes running in different mount namespaces from
1155 the debugger. This makes it possible to attach to processes in
1156 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1157 See "New remote packets" below.
1159 * The "tui reg" command now provides completion for all of the
1160 available register groups, including target specific groups.
1162 * The HISTSIZE environment variable is no longer read when determining
1163 the size of GDB's command history. GDB now instead reads the dedicated
1164 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1165 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1170 ** Memory ports can now be unbuffered.
1174 ** gdb.Objfile objects have a new attribute "username",
1175 which is the name of the objfile as specified by the user,
1176 without, for example, resolving symlinks.
1177 ** You can now write frame unwinders in Python.
1178 ** gdb.Type objects have a new method "optimized_out",
1179 returning optimized out gdb.Value instance of this type.
1180 ** gdb.Value objects have new methods "reference_value" and
1181 "const_value" which return a reference to the value and a
1182 "const" version of the value respectively.
1186 maint print symbol-cache
1187 Print the contents of the symbol cache.
1189 maint print symbol-cache-statistics
1190 Print statistics of symbol cache usage.
1192 maint flush-symbol-cache
1193 Flush the contents of the symbol cache.
1197 Start branch trace recording using Branch Trace Store (BTS) format.
1200 Evaluate expression by using the compiler and print result.
1204 Explicit commands for enabling and disabling tui mode.
1207 set mpx bound on i386 and amd64
1208 Support for bound table investigation on Intel MPX enabled applications.
1212 Start branch trace recording using Intel Processor Trace format.
1215 Print information about branch tracing internals.
1217 maint btrace packet-history
1218 Print the raw branch tracing data.
1220 maint btrace clear-packet-history
1221 Discard the stored raw branch tracing data.
1224 Discard all branch tracing data. It will be fetched and processed
1225 anew by the next "record" command.
1230 Renamed from "set debug dwarf2-die".
1231 show debug dwarf-die
1232 Renamed from "show debug dwarf2-die".
1234 set debug dwarf-read
1235 Renamed from "set debug dwarf2-read".
1236 show debug dwarf-read
1237 Renamed from "show debug dwarf2-read".
1239 maint set dwarf always-disassemble
1240 Renamed from "maint set dwarf2 always-disassemble".
1241 maint show dwarf always-disassemble
1242 Renamed from "maint show dwarf2 always-disassemble".
1244 maint set dwarf max-cache-age
1245 Renamed from "maint set dwarf2 max-cache-age".
1246 maint show dwarf max-cache-age
1247 Renamed from "maint show dwarf2 max-cache-age".
1249 set debug dwarf-line
1250 show debug dwarf-line
1251 Control display of debugging info regarding DWARF line processing.
1254 show max-completions
1255 Set the maximum number of candidates to be considered during
1256 completion. The default value is 200. This limit allows GDB
1257 to avoid generating large completion lists, the computation of
1258 which can cause the debugger to become temporarily unresponsive.
1260 set history remove-duplicates
1261 show history remove-duplicates
1262 Control the removal of duplicate history entries.
1264 maint set symbol-cache-size
1265 maint show symbol-cache-size
1266 Control the size of the symbol cache.
1268 set|show record btrace bts buffer-size
1269 Set and show the size of the ring buffer used for branch tracing in
1271 The obtained size may differ from the requested size. Use "info
1272 record" to see the obtained buffer size.
1274 set debug linux-namespaces
1275 show debug linux-namespaces
1276 Control display of debugging info regarding Linux namespaces.
1278 set|show record btrace pt buffer-size
1279 Set and show the size of the ring buffer used for branch tracing in
1280 Intel Processor Trace format.
1281 The obtained size may differ from the requested size. Use "info
1282 record" to see the obtained buffer size.
1284 maint set|show btrace pt skip-pad
1285 Set and show whether PAD packets are skipped when computing the
1288 * The command 'thread apply all' can now support new option '-ascending'
1289 to call its specified command for all threads in ascending order.
1291 * Python/Guile scripting
1293 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1294 special section named `.debug_gdb_scripts'.
1296 * New remote packets
1298 qXfer:btrace-conf:read
1299 Return the branch trace configuration for the current thread.
1301 Qbtrace-conf:bts:size
1302 Set the requested ring buffer size for branch tracing in BTS format.
1305 Enable Intel Procesor Trace-based branch tracing for the current
1306 process. The remote stub reports support for this packet to GDB's
1309 Qbtrace-conf:pt:size
1310 Set the requested ring buffer size for branch tracing in Intel Processor
1314 Indicates a memory breakpoint instruction was executed, irrespective
1315 of whether it was GDB that planted the breakpoint or the breakpoint
1316 is hardcoded in the program. This is required for correct non-stop
1320 Indicates the target stopped for a hardware breakpoint. This is
1321 required for correct non-stop mode operation.
1324 Return information about files on the remote system.
1326 qXfer:exec-file:read
1327 Return the full absolute name of the file that was executed to
1328 create a process running on the remote system.
1331 Select the filesystem on which vFile: operations with filename
1332 arguments will operate. This is required for GDB to be able to
1333 access files on remote targets where the remote stub does not
1334 share a common filesystem with the inferior(s).
1337 Indicates that a fork system call was executed.
1340 Indicates that a vfork system call was executed.
1342 vforkdone stop reason
1343 Indicates that a vfork child of the specified process has executed
1344 an exec or exit, allowing the vfork parent to resume execution.
1346 fork-events and vfork-events features in qSupported
1347 The qSupported packet allows GDB to request support for fork and
1348 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1349 and the qSupported response can contain the corresponding
1350 'stubfeatures'. Set and show commands can be used to display
1351 whether these features are enabled.
1353 * Extended-remote fork events
1355 ** GDB now has support for fork events on extended-remote Linux
1356 targets. For targets with Linux kernels 2.5.60 and later, this
1357 enables follow-fork-mode and detach-on-fork for both fork and
1358 vfork, as well as fork and vfork catchpoints.
1360 * The info record command now shows the recording format and the
1361 branch tracing configuration for the current thread when using
1362 the btrace record target.
1363 For the BTS format, it shows the ring buffer size.
1365 * GDB now has support for DTrace USDT (Userland Static Defined
1366 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1368 * GDB now supports access to vector registers on S/390 GNU/Linux
1371 * Removed command line options
1373 -xdb HP-UX XDB compatibility mode.
1375 * Removed targets and native configurations
1377 HP/PA running HP-UX hppa*-*-hpux*
1378 Itanium running HP-UX ia64-*-hpux*
1380 * New configure options
1383 This configure option allows the user to build GDB with support for
1384 Intel Processor Trace (default: auto). This requires libipt.
1386 --with-libipt-prefix=PATH
1387 Specify the path to the version of libipt that GDB should use.
1388 $PATH/include should contain the intel-pt.h header and
1389 $PATH/lib should contain the libipt.so library.
1391 *** Changes in GDB 7.9.1
1395 ** Xmethods can now specify a result type.
1397 *** Changes in GDB 7.9
1399 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1403 ** You can now access frame registers from Python scripts.
1404 ** New attribute 'producer' for gdb.Symtab objects.
1405 ** gdb.Objfile objects have a new attribute "progspace",
1406 which is the gdb.Progspace object of the containing program space.
1407 ** gdb.Objfile objects have a new attribute "owner".
1408 ** gdb.Objfile objects have a new attribute "build_id",
1409 which is the build ID generated when the file was built.
1410 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1411 ** A new event "gdb.clear_objfiles" has been added, triggered when
1412 selecting a new file to debug.
1413 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1414 ** New function gdb.lookup_objfile.
1416 New events which are triggered when GDB modifies the state of the
1419 ** gdb.events.inferior_call_pre: Function call is about to be made.
1420 ** gdb.events.inferior_call_post: Function call has just been made.
1421 ** gdb.events.memory_changed: A memory location has been altered.
1422 ** gdb.events.register_changed: A register has been altered.
1424 * New Python-based convenience functions:
1426 ** $_caller_is(name [, number_of_frames])
1427 ** $_caller_matches(regexp [, number_of_frames])
1428 ** $_any_caller_is(name [, number_of_frames])
1429 ** $_any_caller_matches(regexp [, number_of_frames])
1431 * GDB now supports the compilation and injection of source code into
1432 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1433 to compile the source code to object code, and if successful, inject
1434 and execute that code within the current context of the inferior.
1435 Currently the C language is supported. The commands used to
1436 interface with this new feature are:
1438 compile code [-raw|-r] [--] [source code]
1439 compile file [-raw|-r] filename
1443 demangle [-l language] [--] name
1444 Demangle "name" in the specified language, or the current language
1445 if elided. This command is renamed from the "maint demangle" command.
1446 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1447 as "maint demangler-warning".
1449 queue-signal signal-name-or-number
1450 Queue a signal to be delivered to the thread when it is resumed.
1452 add-auto-load-scripts-directory directory
1453 Add entries to the list of directories from which to load auto-loaded
1456 maint print user-registers
1457 List all currently available "user" registers.
1459 compile code [-r|-raw] [--] [source code]
1460 Compile, inject, and execute in the inferior the executable object
1461 code produced by compiling the provided source code.
1463 compile file [-r|-raw] filename
1464 Compile and inject into the inferior the executable object code
1465 produced by compiling the source code stored in the filename
1468 * On resume, GDB now always passes the signal the program had stopped
1469 for to the thread the signal was sent to, even if the user changed
1470 threads before resuming. Previously GDB would often (but not
1471 always) deliver the signal to the thread that happens to be current
1474 * Conversely, the "signal" command now consistently delivers the
1475 requested signal to the current thread. GDB now asks for
1476 confirmation if the program had stopped for a signal and the user
1477 switched threads meanwhile.
1479 * "breakpoint always-inserted" modes "off" and "auto" merged.
1481 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1482 won't remove breakpoints from the target until all threads stop,
1483 even in non-stop mode. The "auto" mode has been removed, and "off"
1484 is now the default mode.
1488 set debug symbol-lookup
1489 show debug symbol-lookup
1490 Control display of debugging info regarding symbol lookup.
1494 ** The -list-thread-groups command outputs an exit-code field for
1495 inferiors that have exited.
1499 MIPS SDE mips*-sde*-elf*
1503 Support for these obsolete configurations has been removed.
1505 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1506 SGI Irix-5.x mips-*-irix5*
1507 SGI Irix-6.x mips-*-irix6*
1508 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1509 VAX running Ultrix vax-*-ultrix*
1511 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1512 and "assf"), have been removed. Use the "sharedlibrary" command, or
1513 its alias "share", instead.
1515 *** Changes in GDB 7.8
1517 * New command line options
1520 This is an alias for the --data-directory option.
1522 * GDB supports printing and modifying of variable length automatic arrays
1523 as specified in ISO C99.
1525 * The ARM simulator now supports instruction level tracing
1526 with or without disassembly.
1530 GDB now has support for scripting using Guile. Whether this is
1531 available is determined at configure time.
1532 Guile version 2.0 or greater is required.
1533 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1535 * New commands (for set/show, see "New options" below)
1539 Invoke CODE by passing it to the Guile interpreter.
1543 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1545 info auto-load guile-scripts [regexp]
1546 Print the list of automatically loaded Guile scripts.
1548 * The source command is now capable of sourcing Guile scripts.
1549 This feature is dependent on the debugger being built with Guile support.
1553 set print symbol-loading (off|brief|full)
1554 show print symbol-loading
1555 Control whether to print informational messages when loading symbol
1556 information for a file. The default is "full", but when debugging
1557 programs with large numbers of shared libraries the amount of output
1558 becomes less useful.
1560 set guile print-stack (none|message|full)
1561 show guile print-stack
1562 Show a stack trace when an error is encountered in a Guile script.
1564 set auto-load guile-scripts (on|off)
1565 show auto-load guile-scripts
1566 Control auto-loading of Guile script files.
1568 maint ada set ignore-descriptive-types (on|off)
1569 maint ada show ignore-descriptive-types
1570 Control whether the debugger should ignore descriptive types in Ada
1571 programs. The default is not to ignore the descriptive types. See
1572 the user manual for more details on descriptive types and the intended
1573 usage of this option.
1575 set auto-connect-native-target
1577 Control whether GDB is allowed to automatically connect to the
1578 native target for the run, attach, etc. commands when not connected
1579 to any target yet. See also "target native" below.
1581 set record btrace replay-memory-access (read-only|read-write)
1582 show record btrace replay-memory-access
1583 Control what memory accesses are allowed during replay.
1585 maint set target-async (on|off)
1586 maint show target-async
1587 This controls whether GDB targets operate in synchronous or
1588 asynchronous mode. Normally the default is asynchronous, if it is
1589 available; but this can be changed to more easily debug problems
1590 occurring only in synchronous mode.
1592 set mi-async (on|off)
1594 Control whether MI asynchronous mode is preferred. This supersedes
1595 "set target-async" of previous GDB versions.
1597 * "set target-async" is deprecated as a CLI option and is now an alias
1598 for "set mi-async" (only puts MI into async mode).
1600 * Background execution commands (e.g., "c&", "s&", etc.) are now
1601 possible ``out of the box'' if the target supports them. Previously
1602 the user would need to explicitly enable the possibility with the
1603 "set target-async on" command.
1605 * New features in the GDB remote stub, GDBserver
1607 ** New option --debug-format=option1[,option2,...] allows one to add
1608 additional text to each output. At present only timestamps
1609 are supported: --debug-format=timestamps.
1610 Timestamps can also be turned on with the
1611 "monitor set debug-format timestamps" command from GDB.
1613 * The 'record instruction-history' command now starts counting instructions
1614 at one. This also affects the instruction ranges reported by the
1615 'record function-call-history' command when given the /i modifier.
1617 * The command 'record function-call-history' supports a new modifier '/c' to
1618 indent the function names based on their call stack depth.
1619 The fields for the '/i' and '/l' modifier have been reordered.
1620 The source line range is now prefixed with 'at'.
1621 The instruction range is now prefixed with 'inst'.
1622 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1623 "record instruction-history" and "list" commands.
1625 * The ranges given as arguments to the 'record function-call-history' and
1626 'record instruction-history' commands are now inclusive.
1628 * The btrace record target now supports the 'record goto' command.
1629 For locations inside the execution trace, the back trace is computed
1630 based on the information stored in the execution trace.
1632 * The btrace record target supports limited reverse execution and replay.
1633 The target does not record data and therefore does not allow reading
1634 memory or registers.
1636 * The "catch syscall" command now works on s390*-linux* targets.
1638 * The "compare-sections" command is no longer specific to target
1639 remote. It now works with all targets.
1641 * All native targets are now consistently called "native".
1642 Consequently, the "target child", "target GNU", "target djgpp",
1643 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1644 commands have been replaced with "target native". The QNX/NTO port
1645 leaves the "procfs" target in place and adds a "native" target for
1646 consistency with other ports. The impact on users should be minimal
1647 as these commands previously either throwed an error, or were
1648 no-ops. The target's name is visible in the output of the following
1649 commands: "help target", "info target", "info files", "maint print
1652 * The "target native" command now connects to the native target. This
1653 can be used to launch native programs even when "set
1654 auto-connect-native-target" is set to off.
1656 * GDB now supports access to Intel MPX registers on GNU/Linux.
1658 * Support for Intel AVX-512 registers on GNU/Linux.
1659 Support displaying and modifying Intel AVX-512 registers
1660 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1662 * New remote packets
1664 qXfer:btrace:read's annex
1665 The qXfer:btrace:read packet supports a new annex 'delta' to read
1666 branch trace incrementally.
1670 ** Valid Python operations on gdb.Value objects representing
1671 structs/classes invoke the corresponding overloaded operators if
1673 ** New `Xmethods' feature in the Python API. Xmethods are
1674 additional methods or replacements for existing methods of a C++
1675 class. This feature is useful for those cases where a method
1676 defined in C++ source code could be inlined or optimized out by
1677 the compiler, making it unavailable to GDB.
1680 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1682 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1683 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1684 its alias "share", instead.
1686 * The commands "set remotebaud" and "show remotebaud" are no longer
1687 supported. Use "set serial baud" and "show serial baud" (respectively)
1692 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1693 target-async". The latter is left as a deprecated alias of the
1694 former for backward compatibility. If the target supports it,
1695 CLI background execution commands are now always possible by
1696 default, independently of whether the frontend stated a
1697 preference for asynchronous execution with "-gdb-set mi-async".
1698 Previously "-gdb-set target-async off" affected both MI execution
1699 commands and CLI execution commands.
1701 *** Changes in GDB 7.7
1703 * Improved support for process record-replay and reverse debugging on
1704 arm*-linux* targets. Support for thumb32 and syscall instruction
1705 recording has been added.
1707 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1709 * GDB now supports Fission DWP file format version 2.
1710 http://gcc.gnu.org/wiki/DebugFission
1712 * New convenience function "$_isvoid", to check whether an expression
1713 is void. A void expression is an expression where the type of the
1714 result is "void". For example, some convenience variables may be
1715 "void" when evaluated (e.g., "$_exitcode" before the execution of
1716 the program being debugged; or an undefined convenience variable).
1717 Another example, when calling a function whose return type is
1720 * The "maintenance print objfiles" command now takes an optional regexp.
1722 * The "catch syscall" command now works on arm*-linux* targets.
1724 * GDB now consistently shows "<not saved>" when printing values of
1725 registers the debug info indicates have not been saved in the frame
1726 and there's nowhere to retrieve them from
1727 (callee-saved/call-clobbered registers):
1732 (gdb) info registers rax
1735 Before, the former would print "<optimized out>", and the latter
1736 "*value not available*".
1738 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1743 ** Frame filters and frame decorators have been added.
1744 ** Temporary breakpoints are now supported.
1745 ** Line tables representation has been added.
1746 ** New attribute 'parent_type' for gdb.Field objects.
1747 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1748 ** New attribute 'name' for gdb.Type objects.
1752 Nios II ELF nios2*-*-elf
1753 Nios II GNU/Linux nios2*-*-linux
1754 Texas Instruments MSP430 msp430*-*-elf
1756 * Removed native configurations
1758 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1759 been removed. ELF variants of these configurations are kept supported.
1761 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1762 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1763 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1764 i[34567]86-*-openbsd3.[0-3]
1765 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1766 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1767 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1771 Like "catch throw", but catches a re-thrown exception.
1772 maint check-psymtabs
1773 Renamed from old "maint check-symtabs".
1775 Perform consistency checks on symtabs.
1776 maint expand-symtabs
1777 Expand symtabs matching an optional regexp.
1780 Display the details of GDB configure-time options.
1782 maint set|show per-command
1783 maint set|show per-command space
1784 maint set|show per-command time
1785 maint set|show per-command symtab
1786 Enable display of per-command gdb resource usage.
1788 remove-symbol-file FILENAME
1789 remove-symbol-file -a ADDRESS
1790 Remove a symbol file added via add-symbol-file. The file to remove
1791 can be identified by its filename or by an address that lies within
1792 the boundaries of this symbol file in memory.
1795 info exceptions REGEXP
1796 Display the list of Ada exceptions defined in the program being
1797 debugged. If provided, only the exceptions whose names match REGEXP
1802 set debug symfile off|on
1804 Control display of debugging info regarding reading symbol files and
1805 symbol tables within those files
1807 set print raw frame-arguments
1808 show print raw frame-arguments
1809 Set/show whether to print frame arguments in raw mode,
1810 disregarding any defined pretty-printers.
1812 set remote trace-status-packet
1813 show remote trace-status-packet
1814 Set/show the use of remote protocol qTStatus packet.
1818 Control display of debugging messages related to Nios II targets.
1822 Control whether target-assisted range stepping is enabled.
1824 set startup-with-shell
1825 show startup-with-shell
1826 Specifies whether Unix child processes are started via a shell or
1831 Use the target memory cache for accesses to the code segment. This
1832 improves performance of remote debugging (particularly disassembly).
1834 * You can now use a literal value 'unlimited' for options that
1835 interpret 0 or -1 as meaning "unlimited". E.g., "set
1836 trace-buffer-size unlimited" is now an alias for "set
1837 trace-buffer-size -1" and "set height unlimited" is now an alias for
1840 * The "set debug symtab-create" debugging option of GDB has been changed to
1841 accept a verbosity level. 0 means "off", 1 provides basic debugging
1842 output, and values of 2 or greater provides more verbose output.
1844 * New command-line options
1846 Display the details of GDB configure-time options.
1848 * The command 'tsave' can now support new option '-ctf' to save trace
1849 buffer in Common Trace Format.
1851 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1854 * GDB now implements the the C++ 'typeid' operator.
1856 * The new convenience variable $_exception holds the exception being
1857 thrown or caught at an exception-related catchpoint.
1859 * The exception-related catchpoints, like "catch throw", now accept a
1860 regular expression which can be used to filter exceptions by type.
1862 * The new convenience variable $_exitsignal is automatically set to
1863 the terminating signal number when the program being debugged dies
1864 due to an uncaught signal.
1868 ** All MI commands now accept an optional "--language" option.
1869 Support for this feature can be verified by using the "-list-features"
1870 command, which should contain "language-option".
1872 ** The new command -info-gdb-mi-command allows the user to determine
1873 whether a GDB/MI command is supported or not.
1875 ** The "^error" result record returned when trying to execute an undefined
1876 GDB/MI command now provides a variable named "code" whose content is the
1877 "undefined-command" error code. Support for this feature can be verified
1878 by using the "-list-features" command, which should contain
1879 "undefined-command-error-code".
1881 ** The -trace-save MI command can optionally save trace buffer in Common
1884 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1886 ** The command -data-list-register-values now accepts an optional
1887 "--skip-unavailable" option. When used, only the available registers
1890 ** The new command -trace-frame-collected dumps collected variables,
1891 computed expressions, tvars, memory and registers in a traceframe.
1893 ** The commands -stack-list-locals, -stack-list-arguments and
1894 -stack-list-variables now accept an option "--skip-unavailable".
1895 When used, only the available locals or arguments are displayed.
1897 ** The -exec-run command now accepts an optional "--start" option.
1898 When used, the command follows the same semantics as the "start"
1899 command, stopping the program's execution at the start of its
1900 main subprogram. Support for this feature can be verified using
1901 the "-list-features" command, which should contain
1902 "exec-run-start-option".
1904 ** The new commands -catch-assert and -catch-exceptions insert
1905 catchpoints stopping the program when Ada exceptions are raised.
1907 ** The new command -info-ada-exceptions provides the equivalent of
1908 the new "info exceptions" command.
1910 * New system-wide configuration scripts
1911 A GDB installation now provides scripts suitable for use as system-wide
1912 configuration scripts for the following systems:
1916 * GDB now supports target-assigned range stepping with remote targets.
1917 This improves the performance of stepping source lines by reducing
1918 the number of control packets from/to GDB. See "New remote packets"
1921 * GDB now understands the element 'tvar' in the XML traceframe info.
1922 It has the id of the collected trace state variables.
1924 * On S/390 targets that provide the transactional-execution feature,
1925 the program interruption transaction diagnostic block (TDB) is now
1926 represented as a number of additional "registers" in GDB.
1928 * New remote packets
1932 The vCont packet supports a new 'r' action, that tells the remote
1933 stub to step through an address range itself, without GDB
1934 involvemement at each single-step.
1936 qXfer:libraries-svr4:read's annex
1937 The previously unused annex of the qXfer:libraries-svr4:read packet
1938 is now used to support passing an argument list. The remote stub
1939 reports support for this argument list to GDB's qSupported query.
1940 The defined arguments are "start" and "prev", used to reduce work
1941 necessary for library list updating, resulting in significant
1944 * New features in the GDB remote stub, GDBserver
1946 ** GDBserver now supports target-assisted range stepping. Currently
1947 enabled on x86/x86_64 GNU/Linux targets.
1949 ** GDBserver now adds element 'tvar' in the XML in the reply to
1950 'qXfer:traceframe-info:read'. It has the id of the collected
1951 trace state variables.
1953 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1956 * New 'z' formatter for printing and examining memory, this displays the
1957 value as hexadecimal zero padded on the left to the size of the type.
1959 * GDB can now use Windows x64 unwinding data.
1961 * The "set remotebaud" command has been replaced by "set serial baud".
1962 Similarly, "show remotebaud" has been replaced by "show serial baud".
1963 The "set remotebaud" and "show remotebaud" commands are still available
1964 to provide backward compatibility with older versions of GDB.
1966 *** Changes in GDB 7.6
1968 * Target record has been renamed to record-full.
1969 Record/replay is now enabled with the "record full" command.
1970 This also affects settings that are associated with full record/replay
1971 that have been moved from "set/show record" to "set/show record full":
1973 set|show record full insn-number-max
1974 set|show record full stop-at-limit
1975 set|show record full memory-query
1977 * A new record target "record-btrace" has been added. The new target
1978 uses hardware support to record the control-flow of a process. It
1979 does not support replaying the execution, but it implements the
1980 below new commands for investigating the recorded execution log.
1981 This new recording method can be enabled using:
1985 The "record-btrace" target is only available on Intel Atom processors
1986 and requires a Linux kernel 2.6.32 or later.
1988 * Two new commands have been added for record/replay to give information
1989 about the recorded execution without having to replay the execution.
1990 The commands are only supported by "record btrace".
1992 record instruction-history prints the execution history at
1993 instruction granularity
1995 record function-call-history prints the execution history at
1996 function granularity
1998 * New native configurations
2000 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2001 FreeBSD/powerpc powerpc*-*-freebsd
2002 x86_64/Cygwin x86_64-*-cygwin*
2003 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2007 ARM AArch64 aarch64*-*-elf
2008 ARM AArch64 GNU/Linux aarch64*-*-linux
2009 Lynx 178 PowerPC powerpc-*-lynx*178
2010 x86_64/Cygwin x86_64-*-cygwin*
2011 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2013 * If the configured location of system.gdbinit file (as given by the
2014 --with-system-gdbinit option at configure time) is in the
2015 data-directory (as specified by --with-gdb-datadir at configure
2016 time) or in one of its subdirectories, then GDB will look for the
2017 system-wide init file in the directory specified by the
2018 --data-directory command-line option.
2020 * New command line options:
2022 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2023 other initialization files, unlike -nx which disables all of them.
2025 * Removed command line options
2027 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2030 * The 'ptype' and 'whatis' commands now accept an argument to control
2033 * 'info proc' now works on some core files.
2037 ** Vectors can be created with gdb.Type.vector.
2039 ** Python's atexit.register now works in GDB.
2041 ** Types can be pretty-printed via a Python API.
2043 ** Python 3 is now supported (in addition to Python 2.4 or later)
2045 ** New class gdb.Architecture exposes GDB's internal representation
2046 of architecture in the Python API.
2048 ** New method Frame.architecture returns the gdb.Architecture object
2049 corresponding to the frame's architecture.
2051 * New Python-based convenience functions:
2053 ** $_memeq(buf1, buf2, length)
2054 ** $_streq(str1, str2)
2056 ** $_regex(str, regex)
2058 * The 'cd' command now defaults to using '~' (the home directory) if not
2061 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2062 default for GCC since November 2000.
2064 * The command 'forward-search' can now be abbreviated as 'fo'.
2066 * The command 'info tracepoints' can now display 'installed on target'
2067 or 'not installed on target' for each non-pending location of tracepoint.
2069 * New configure options
2071 --enable-libmcheck/--disable-libmcheck
2072 By default, development versions are built with -lmcheck on hosts
2073 that support it, in order to help track memory corruption issues.
2074 Release versions, on the other hand, are built without -lmcheck
2075 by default. The --enable-libmcheck/--disable-libmcheck configure
2076 options allow the user to override that default.
2077 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2078 This configure option allows the user to build GDB with
2079 libbabeltrace using which GDB can read Common Trace Format data.
2081 * New commands (for set/show, see "New options" below)
2084 Catch signals. This is similar to "handle", but allows commands and
2085 conditions to be attached.
2088 List the BFDs known to GDB.
2090 python-interactive [command]
2092 Start a Python interactive prompt, or evaluate the optional command
2093 and print the result of expressions.
2096 "py" is a new alias for "python".
2098 enable type-printer [name]...
2099 disable type-printer [name]...
2100 Enable or disable type printers.
2104 ** For the Renesas Super-H architecture, the "regs" command has been removed
2105 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2110 set print type methods (on|off)
2111 show print type methods
2112 Control whether method declarations are displayed by "ptype".
2113 The default is to show them.
2115 set print type typedefs (on|off)
2116 show print type typedefs
2117 Control whether typedef definitions are displayed by "ptype".
2118 The default is to show them.
2120 set filename-display basename|relative|absolute
2121 show filename-display
2122 Control the way in which filenames is displayed.
2123 The default is "relative", which preserves previous behavior.
2125 set trace-buffer-size
2126 show trace-buffer-size
2127 Request target to change the size of trace buffer.
2129 set remote trace-buffer-size-packet auto|on|off
2130 show remote trace-buffer-size-packet
2131 Control the use of the remote protocol `QTBuffer:size' packet.
2135 Control display of debugging messages related to ARM AArch64.
2138 set debug coff-pe-read
2139 show debug coff-pe-read
2140 Control display of debugging messages related to reading of COFF/PE
2145 Control display of debugging messages related to Mach-O symbols
2148 set debug notification
2149 show debug notification
2150 Control display of debugging info for async remote notification.
2154 ** Command parameter changes are now notified using new async record
2155 "=cmd-param-changed".
2156 ** Trace frame changes caused by command "tfind" are now notified using
2157 new async record "=traceframe-changed".
2158 ** The creation, deletion and modification of trace state variables
2159 are now notified using new async records "=tsv-created",
2160 "=tsv-deleted" and "=tsv-modified".
2161 ** The start and stop of process record are now notified using new
2162 async record "=record-started" and "=record-stopped".
2163 ** Memory changes are now notified using new async record
2165 ** The data-disassemble command response will include a "fullname" field
2166 containing the absolute file name when source has been requested.
2167 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2168 command, to allow pattern filling of memory areas.
2169 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2170 library load/unload events.
2171 ** The response to breakpoint commands and breakpoint async records
2172 includes an "installed" field containing a boolean state about each
2173 non-pending tracepoint location is whether installed on target or not.
2174 ** Output of the "-trace-status" command includes a "trace-file" field
2175 containing the name of the trace file being examined. This field is
2176 optional, and only present when examining a trace file.
2177 ** The "fullname" field is now always present along with the "file" field,
2178 even if the file cannot be found by GDB.
2180 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2181 You must have the LZMA library available when configuring GDB for this
2182 feature to be enabled. For more information, see:
2183 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2185 * New remote packets
2188 Set the size of trace buffer. The remote stub reports support for this
2189 packet to gdb's qSupported query.
2192 Enable Branch Trace Store (BTS)-based branch tracing for the current
2193 thread. The remote stub reports support for this packet to gdb's
2197 Disable branch tracing for the current thread. The remote stub reports
2198 support for this packet to gdb's qSupported query.
2201 Read the traced branches for the current thread. The remote stub
2202 reports support for this packet to gdb's qSupported query.
2204 *** Changes in GDB 7.5
2206 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2207 for more x32 ABI info.
2209 * GDB now supports access to MIPS DSP registers on Linux targets.
2211 * GDB now supports debugging microMIPS binaries.
2213 * The "info os" command on GNU/Linux can now display information on
2214 several new classes of objects managed by the operating system:
2215 "info os procgroups" lists process groups
2216 "info os files" lists file descriptors
2217 "info os sockets" lists internet-domain sockets
2218 "info os shm" lists shared-memory regions
2219 "info os semaphores" lists semaphores
2220 "info os msg" lists message queues
2221 "info os modules" lists loaded kernel modules
2223 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2224 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2225 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2226 options and inspect the probe arguments using the new $_probe_arg family
2227 of convenience variables. You can obtain more information about SystemTap
2228 in <http://sourceware.org/systemtap/>.
2230 * GDB now supports reversible debugging on ARM, it allows you to
2231 debug basic ARM and THUMB instructions, and provides
2232 record/replay support.
2234 * The option "symbol-reloading" has been deleted as it is no longer used.
2238 ** GDB commands implemented in Python can now be put in command class
2241 ** The "maint set python print-stack on|off" is now deleted.
2243 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2244 apply "flag enum"-style pretty-printing to any enum.
2246 ** gdb.lookup_symbol can now work when there is no current frame.
2248 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2249 the source at which the symbol was defined.
2251 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2252 method 'value'. The former indicates whether the symbol needs a
2253 frame in order to compute its value, and the latter computes the
2256 ** A new method 'referenced_value' on gdb.Value objects which can
2257 dereference pointer as well as C++ reference values.
2259 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2260 which return the global and static blocks (as gdb.Block objects),
2261 of the underlying symbol table, respectively.
2263 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2264 object associated with a PC value.
2266 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2267 of the address range occupied by code for the current source line.
2269 * Go language support.
2270 GDB now supports debugging programs written in the Go programming
2273 * GDBserver now supports stdio connections.
2274 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2276 * The binary "gdbtui" can no longer be built or installed.
2277 Use "gdb -tui" instead.
2279 * GDB will now print "flag" enums specially. A flag enum is one where
2280 all the enumerator values have no bits in common when pairwise
2281 "and"ed. When printing a value whose type is a flag enum, GDB will
2282 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2283 (gdb) print (enum E) 3
2286 * The filename part of a linespec will now match trailing components
2287 of a source file name. For example, "break gcc/expr.c:1000" will
2288 now set a breakpoint in build/gcc/expr.c, but not
2289 build/libcpp/expr.c.
2291 * The "info proc" and "generate-core-file" commands will now also
2292 work on remote targets connected to GDBserver on Linux.
2294 * The command "info catch" has been removed. It has been disabled
2295 since December 2007.
2297 * The "catch exception" and "catch assert" commands now accept
2298 a condition at the end of the command, much like the "break"
2299 command does. For instance:
2301 (gdb) catch exception Constraint_Error if Barrier = True
2303 Previously, it was possible to add a condition to such catchpoints,
2304 but it had to be done as a second step, after the catchpoint had been
2305 created, using the "condition" command.
2307 * The "info static-tracepoint-marker" command will now also work on
2308 native Linux targets with in-process agent.
2310 * GDB can now set breakpoints on inlined functions.
2312 * The .gdb_index section has been updated to include symbols for
2313 inlined functions. GDB will ignore older .gdb_index sections by
2314 default, which could cause symbol files to be loaded more slowly
2315 until their .gdb_index sections can be recreated. The new command
2316 "set use-deprecated-index-sections on" will cause GDB to use any older
2317 .gdb_index sections it finds. This will restore performance, but the
2318 ability to set breakpoints on inlined functions will be lost in symbol
2319 files with older .gdb_index sections.
2321 The .gdb_index section has also been updated to record more information
2322 about each symbol. This speeds up the "info variables", "info functions"
2323 and "info types" commands when used with programs having the .gdb_index
2324 section, as well as speeding up debugging with shared libraries using
2325 the .gdb_index section.
2327 * Ada support for GDB/MI Variable Objects has been added.
2329 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2334 ** New command -info-os is the MI equivalent of "info os".
2336 ** Output logs ("set logging" and related) now include MI output.
2340 ** "set use-deprecated-index-sections on|off"
2341 "show use-deprecated-index-sections on|off"
2342 Controls the use of deprecated .gdb_index sections.
2344 ** "catch load" and "catch unload" can be used to stop when a shared
2345 library is loaded or unloaded, respectively.
2347 ** "enable count" can be used to auto-disable a breakpoint after
2350 ** "info vtbl" can be used to show the virtual method tables for
2351 C++ and Java objects.
2353 ** "explore" and its sub commands "explore value" and "explore type"
2354 can be used to recursively explore values and types of
2355 expressions. These commands are available only if GDB is
2356 configured with '--with-python'.
2358 ** "info auto-load" shows status of all kinds of auto-loaded files,
2359 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2360 sequences of commands files, "info auto-load python-scripts"
2361 shows status of auto-loading Python script files,
2362 "info auto-load local-gdbinit" shows status of loading init file
2363 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2364 status of inferior specific thread debugging shared library loading.
2366 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2367 and "show auto-load-scripts" commands have been deprecated, use their
2368 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2369 and "show auto-load python-scripts" counterparts instead.
2371 ** "dprintf location,format,args..." creates a dynamic printf, which
2372 is basically a breakpoint that does a printf and immediately
2373 resumes your program's execution, so it is like a printf that you
2374 can insert dynamically at runtime instead of at compiletime.
2376 ** "set print symbol"
2378 Controls whether GDB attempts to display the symbol, if any,
2379 corresponding to addresses it prints. This defaults to "on", but
2380 you can set it to "off" to restore GDB's previous behavior.
2382 * Deprecated commands
2384 ** For the Renesas Super-H architecture, the "regs" command has been
2385 deprecated, and "info all-registers" should be used instead.
2389 Renesas RL78 rl78-*-elf
2390 HP OpenVMS ia64 ia64-hp-openvms*
2392 * GDBserver supports evaluation of breakpoint conditions. When
2393 support is advertised by GDBserver, GDB may be told to send the
2394 breakpoint conditions in bytecode form to GDBserver. GDBserver
2395 will only report the breakpoint trigger to GDB when its condition
2400 set mips compression
2401 show mips compression
2402 Select the compressed ISA encoding used in functions that have no symbol
2403 information available. The encoding can be set to either of:
2406 and is updated automatically from ELF file flags if available.
2408 set breakpoint condition-evaluation
2409 show breakpoint condition-evaluation
2410 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2411 GDBserver ("target"). Default option "auto" chooses the most efficient
2413 This option can improve debugger efficiency depending on the speed of the
2417 Disable auto-loading globally.
2420 Show auto-loading setting of all kinds of auto-loaded files.
2422 set auto-load gdb-scripts on|off
2423 show auto-load gdb-scripts
2424 Control auto-loading of GDB canned sequences of commands files.
2426 set auto-load python-scripts on|off
2427 show auto-load python-scripts
2428 Control auto-loading of Python script files.
2430 set auto-load local-gdbinit on|off
2431 show auto-load local-gdbinit
2432 Control loading of init file (.gdbinit) from current directory.
2434 set auto-load libthread-db on|off
2435 show auto-load libthread-db
2436 Control auto-loading of inferior specific thread debugging shared library.
2438 set auto-load scripts-directory <dir1>[:<dir2>...]
2439 show auto-load scripts-directory
2440 Set a list of directories from which to load auto-loaded scripts.
2441 Automatically loaded Python scripts and GDB scripts are located in one
2442 of the directories listed by this option.
2443 The delimiter (':' above) may differ according to the host platform.
2445 set auto-load safe-path <dir1>[:<dir2>...]
2446 show auto-load safe-path
2447 Set a list of directories from which it is safe to auto-load files.
2448 The delimiter (':' above) may differ according to the host platform.
2450 set debug auto-load on|off
2451 show debug auto-load
2452 Control display of debugging info for auto-loading the files above.
2454 set dprintf-style gdb|call|agent
2456 Control the way in which a dynamic printf is performed; "gdb"
2457 requests a GDB printf command, while "call" causes dprintf to call a
2458 function in the inferior. "agent" requests that the target agent
2459 (such as GDBserver) do the printing.
2461 set dprintf-function <expr>
2462 show dprintf-function
2463 set dprintf-channel <expr>
2464 show dprintf-channel
2465 Set the function and optional first argument to the call when using
2466 the "call" style of dynamic printf.
2468 set disconnected-dprintf on|off
2469 show disconnected-dprintf
2470 Control whether agent-style dynamic printfs continue to be in effect
2471 after GDB disconnects.
2473 * New configure options
2475 --with-auto-load-dir
2476 Configure default value for the 'set auto-load scripts-directory'
2477 setting above. It defaults to '$debugdir:$datadir/auto-load',
2478 $debugdir representing global debugging info directories (available
2479 via 'show debug-file-directory') and $datadir representing GDB's data
2480 directory (available via 'show data-directory').
2482 --with-auto-load-safe-path
2483 Configure default value for the 'set auto-load safe-path' setting
2484 above. It defaults to the --with-auto-load-dir setting.
2486 --without-auto-load-safe-path
2487 Set 'set auto-load safe-path' to '/', effectively disabling this
2490 * New remote packets
2492 z0/z1 conditional breakpoints extension
2494 The z0/z1 breakpoint insertion packets have been extended to carry
2495 a list of conditional expressions over to the remote stub depending on the
2496 condition evaluation mode. The use of this extension can be controlled
2497 via the "set remote conditional-breakpoints-packet" command.
2501 Specify the signals which the remote stub may pass to the debugged
2502 program without GDB involvement.
2504 * New command line options
2506 --init-command=FILE, -ix Like --command, -x but execute it
2507 before loading inferior.
2508 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2509 execute it before loading inferior.
2511 *** Changes in GDB 7.4
2513 * GDB now handles ambiguous linespecs more consistently; the existing
2514 FILE:LINE support has been expanded to other types of linespecs. A
2515 breakpoint will now be set on all matching locations in all
2516 inferiors, and locations will be added or removed according to
2519 * GDB now allows you to skip uninteresting functions and files when
2520 stepping with the "skip function" and "skip file" commands.
2522 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2523 and "show remote hardware-watchpoint-length-limit". These allows to
2524 set or show the maximum length limit (in bytes) of a remote
2525 target hardware watchpoint.
2527 This allows e.g. to use "unlimited" hardware watchpoints with the
2528 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2529 watchpoints are slower than real hardware watchpoints but are
2530 significantly faster than gdb software watchpoints.
2534 ** The register_pretty_printer function in module gdb.printing now takes
2535 an optional `replace' argument. If True, the new printer replaces any
2538 ** The "maint set python print-stack on|off" command has been
2539 deprecated and will be deleted in GDB 7.5.
2540 A new command: "set python print-stack none|full|message" has
2541 replaced it. Additionally, the default for "print-stack" is
2542 now "message", which just prints the error message without
2545 ** A prompt substitution hook (prompt_hook) is now available to the
2548 ** A new Python module, gdb.prompt has been added to the GDB Python
2549 modules library. This module provides functionality for
2550 escape sequences in prompts (used by set/show
2551 extended-prompt). These escape sequences are replaced by their
2552 corresponding value.
2554 ** Python commands and convenience-functions located in
2555 'data-directory'/python/gdb/command and
2556 'data-directory'/python/gdb/function are now automatically loaded
2559 ** Blocks now provide four new attributes. global_block and
2560 static_block will return the global and static blocks
2561 respectively. is_static and is_global are boolean attributes
2562 that indicate if the block is one of those two types.
2564 ** Symbols now provide the "type" attribute, the type of the symbol.
2566 ** The "gdb.breakpoint" function has been deprecated in favor of
2569 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2570 of a function. This class is based on the "finish" command
2571 available in the CLI.
2573 ** Type objects for struct and union types now allow access to
2574 the fields using standard Python dictionary (mapping) methods.
2575 For example, "some_type['myfield']" now works, as does
2576 "some_type.items()".
2578 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2581 ** A new function, "deep_items" has been added to the gdb.types
2582 module in the GDB Python modules library. This function returns
2583 an iterator over the fields of a struct or union type. Unlike
2584 the standard Python "iteritems" method, it will recursively traverse
2585 any anonymous fields.
2589 ** "*stopped" events can report several new "reason"s, such as
2592 ** Breakpoint changes are now notified using new async records, like
2593 "=breakpoint-modified".
2595 ** New command -ada-task-info.
2597 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2598 $sdir specifies the default system locations of shared libraries.
2599 $pdir specifies the directory where the libpthread used by the application
2602 GDB no longer looks in $sdir and $pdir after it has searched the directories
2603 mentioned in libthread-db-search-path. If you want to search those
2604 directories, they must be specified in libthread-db-search-path.
2605 The default value of libthread-db-search-path on GNU/Linux and Solaris
2606 systems is now "$sdir:$pdir".
2608 $pdir is not supported by gdbserver, it is currently ignored.
2609 $sdir is supported by gdbserver.
2611 * New configure option --with-iconv-bin.
2612 When using the internationalization support like the one in the GNU C
2613 library, GDB will invoke the "iconv" program to get a list of supported
2614 character sets. If this program lives in a non-standard location, one can
2615 use this option to specify where to find it.
2617 * When natively debugging programs on PowerPC BookE processors running
2618 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2619 watchpoints, which specify a mask in addition to an address to watch.
2620 The mask specifies that some bits of an address (the bits which are
2621 reset in the mask) should be ignored when matching the address accessed
2622 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2623 section in the user manual for more details.
2625 * The new option --once causes GDBserver to stop listening for connections once
2626 the first connection is made. The listening port used by GDBserver will
2627 become available after that.
2629 * New commands "info macros" and "alias" have been added.
2631 * New function parameters suffix @entry specifies value of function parameter
2632 at the time the function got called. Entry values are available only since
2638 "!" is now an alias of the "shell" command.
2639 Note that no space is needed between "!" and SHELL COMMAND.
2643 watch EXPRESSION mask MASK_VALUE
2644 The watch command now supports the mask argument which allows creation
2645 of masked watchpoints, if the current architecture supports this feature.
2647 info auto-load-scripts [REGEXP]
2648 This command was formerly named "maintenance print section-scripts".
2649 It is now generally useful and is no longer a maintenance-only command.
2651 info macro [-all] [--] MACRO
2652 The info macro command has new options `-all' and `--'. The first for
2653 printing all definitions of a macro. The second for explicitly specifying
2654 the end of arguments and the beginning of the macro name in case the macro
2655 name starts with a hyphen.
2657 collect[/s] EXPRESSIONS
2658 The tracepoint collect command now takes an optional modifier "/s"
2659 that directs it to dereference pointer-to-character types and
2660 collect the bytes of memory up to a zero byte. The behavior is
2661 similar to what you see when you use the regular print command on a
2662 string. An optional integer following the "/s" sets a bound on the
2663 number of bytes that will be collected.
2666 The trace start command now interprets any supplied arguments as a
2667 note to be recorded with the trace run, with an effect similar to
2668 setting the variable trace-notes.
2671 The trace stop command now interprets any arguments as a note to be
2672 mentioned along with the tstatus report that the trace was stopped
2673 with a command. The effect is similar to setting the variable
2676 * Tracepoints can now be enabled and disabled at any time after a trace
2677 experiment has been started using the standard "enable" and "disable"
2678 commands. It is now possible to start a trace experiment with no enabled
2679 tracepoints; GDB will display a warning, but will allow the experiment to
2680 begin, assuming that tracepoints will be enabled as needed while the trace
2683 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2684 locations with 4-byte instructions, when they were previously
2685 limited to locations with instructions of 5 bytes or longer.
2689 set debug dwarf2-read
2690 show debug dwarf2-read
2691 Turns on or off display of debugging messages related to reading
2692 DWARF debug info. The default is off.
2694 set debug symtab-create
2695 show debug symtab-create
2696 Turns on or off display of debugging messages related to symbol table
2697 creation. The default is off.
2700 show extended-prompt
2701 Set the GDB prompt, and allow escape sequences to be inserted to
2702 display miscellaneous information (see 'help set extended-prompt'
2703 for the list of sequences). This prompt (and any information
2704 accessed through the escape sequences) is updated every time the
2705 prompt is displayed.
2707 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2708 show print entry-values
2709 Set printing of frame argument values at function entry. In some cases
2710 GDB can determine the value of function argument which was passed by the
2711 function caller, even if the value was modified inside the called function.
2713 set debug entry-values
2714 show debug entry-values
2715 Control display of debugging info for determining frame argument values at
2716 function entry and virtual tail call frames.
2718 set basenames-may-differ
2719 show basenames-may-differ
2720 Set whether a source file may have multiple base names.
2721 (A "base name" is the name of a file with the directory part removed.
2722 Example: The base name of "/home/user/hello.c" is "hello.c".)
2723 If set, GDB will canonicalize file names (e.g., expand symlinks)
2724 before comparing them. Canonicalization is an expensive operation,
2725 but it allows the same file be known by more than one base name.
2726 If not set (the default), all source files are assumed to have just
2727 one base name, and gdb will do file name comparisons more efficiently.
2733 Set a user name and notes for the current and any future trace runs.
2734 This is useful for long-running and/or disconnected traces, to
2735 inform others (or yourself) as to who is running the trace, supply
2736 contact information, or otherwise explain what is going on.
2738 set trace-stop-notes
2739 show trace-stop-notes
2740 Set a note attached to the trace run, that is displayed when the
2741 trace has been stopped by a tstop command. This is useful for
2742 instance as an explanation, if you are stopping a trace run that was
2743 started by someone else.
2745 * New remote packets
2749 Dynamically enable a tracepoint in a started trace experiment.
2753 Dynamically disable a tracepoint in a started trace experiment.
2757 Set the user and notes of the trace run.
2761 Query the current status of a tracepoint.
2765 Query the minimum length of instruction at which a fast tracepoint may
2768 * Dcache size (number of lines) and line-size are now runtime-configurable
2769 via "set dcache line" and "set dcache line-size" commands.
2773 Texas Instruments TMS320C6x tic6x-*-*
2777 Renesas RL78 rl78-*-elf
2779 *** Changes in GDB 7.3.1
2781 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2783 *** Changes in GDB 7.3
2785 * GDB has a new command: "thread find [REGEXP]".
2786 It finds the thread id whose name, target id, or thread extra info
2787 matches the given regular expression.
2789 * The "catch syscall" command now works on mips*-linux* targets.
2791 * The -data-disassemble MI command now supports modes 2 and 3 for
2792 dumping the instruction opcodes.
2794 * New command line options
2796 -data-directory DIR Specify DIR as the "data-directory".
2797 This is mostly for testing purposes.
2799 * The "maint set python auto-load on|off" command has been renamed to
2800 "set auto-load-scripts on|off".
2802 * GDB has a new command: "set directories".
2803 It is like the "dir" command except that it replaces the
2804 source path list instead of augmenting it.
2806 * GDB now understands thread names.
2808 On GNU/Linux, "info threads" will display the thread name as set by
2809 prctl or pthread_setname_np.
2811 There is also a new command, "thread name", which can be used to
2812 assign a name internally for GDB to display.
2815 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2816 has been integrated into GDB.
2820 ** The function gdb.Write now accepts an optional keyword 'stream'.
2821 This keyword, when provided, will direct the output to either
2822 stdout, stderr, or GDB's logging output.
2824 ** Parameters can now be be sub-classed in Python, and in particular
2825 you may implement the get_set_doc and get_show_doc functions.
2826 This improves how Parameter set/show documentation is processed
2827 and allows for more dynamic content.
2829 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2830 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2831 have an is_valid method.
2833 ** Breakpoints can now be sub-classed in Python, and in particular
2834 you may implement a 'stop' function that is executed each time
2835 the inferior reaches that breakpoint.
2837 ** New function gdb.lookup_global_symbol looks up a global symbol.
2839 ** GDB values in Python are now callable if the value represents a
2840 function. For example, if 'some_value' represents a function that
2841 takes two integer parameters and returns a value, you can call
2842 that function like so:
2844 result = some_value (10,20)
2846 ** Module gdb.types has been added.
2847 It contains a collection of utilities for working with gdb.Types objects:
2848 get_basic_type, has_field, make_enum_dict.
2850 ** Module gdb.printing has been added.
2851 It contains utilities for writing and registering pretty-printers.
2852 New classes: PrettyPrinter, SubPrettyPrinter,
2853 RegexpCollectionPrettyPrinter.
2854 New function: register_pretty_printer.
2856 ** New commands "info pretty-printers", "enable pretty-printer" and
2857 "disable pretty-printer" have been added.
2859 ** gdb.parameter("directories") is now available.
2861 ** New function gdb.newest_frame returns the newest frame in the
2864 ** The gdb.InferiorThread class has a new "name" attribute. This
2865 holds the thread's name.
2867 ** Python Support for Inferior events.
2868 Python scripts can add observers to be notified of events
2869 occurring in the process being debugged.
2870 The following events are currently supported:
2871 - gdb.events.cont Continue event.
2872 - gdb.events.exited Inferior exited event.
2873 - gdb.events.stop Signal received, and Breakpoint hit events.
2877 ** GDB now puts template parameters in scope when debugging in an
2878 instantiation. For example, if you have:
2880 template<int X> int func (void) { return X; }
2882 then if you step into func<5>, "print X" will show "5". This
2883 feature requires proper debuginfo support from the compiler; it
2884 was added to GCC 4.5.
2886 ** The motion commands "next", "finish", "until", and "advance" now
2887 work better when exceptions are thrown. In particular, GDB will
2888 no longer lose control of the inferior; instead, the GDB will
2889 stop the inferior at the point at which the exception is caught.
2890 This functionality requires a change in the exception handling
2891 code that was introduced in GCC 4.5.
2893 * GDB now follows GCC's rules on accessing volatile objects when
2894 reading or writing target state during expression evaluation.
2895 One notable difference to prior behavior is that "print x = 0"
2896 no longer generates a read of x; the value of the assignment is
2897 now always taken directly from the value being assigned.
2899 * GDB now has some support for using labels in the program's source in
2900 linespecs. For instance, you can use "advance label" to continue
2901 execution to a label.
2903 * GDB now has support for reading and writing a new .gdb_index
2904 section. This section holds a fast index of DWARF debugging
2905 information and can be used to greatly speed up GDB startup and
2906 operation. See the documentation for `save gdb-index' for details.
2908 * The "watch" command now accepts an optional "-location" argument.
2909 When used, this causes GDB to watch the memory referred to by the
2910 expression. Such a watchpoint is never deleted due to it going out
2913 * GDB now supports thread debugging of core dumps on GNU/Linux.
2915 GDB now activates thread debugging using the libthread_db library
2916 when debugging GNU/Linux core dumps, similarly to when debugging
2917 live processes. As a result, when debugging a core dump file, GDB
2918 is now able to display pthread_t ids of threads. For example, "info
2919 threads" shows the same output as when debugging the process when it
2920 was live. In earlier releases, you'd see something like this:
2923 * 1 LWP 6780 main () at main.c:10
2925 While now you see this:
2928 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2930 It is also now possible to inspect TLS variables when debugging core
2933 When debugging a core dump generated on a machine other than the one
2934 used to run GDB, you may need to point GDB at the correct
2935 libthread_db library with the "set libthread-db-search-path"
2936 command. See the user manual for more details on this command.
2938 * When natively debugging programs on PowerPC BookE processors running
2939 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2940 which stop execution of the inferior whenever it executes an instruction
2941 at any address within the specified range. See the "PowerPC Embedded"
2942 section in the user manual for more details.
2944 * New features in the GDB remote stub, GDBserver
2946 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2947 and i686 LynxOS (version 5.x).
2949 ** GDBserver is now supported on Blackfin Linux.
2951 * New native configurations
2953 ia64 HP-UX ia64-*-hpux*
2957 Analog Devices, Inc. Blackfin Processor bfin-*
2959 * Ada task switching is now supported on sparc-elf targets when
2960 debugging a program using the Ravenscar Profile. For more information,
2961 see the "Tasking Support when using the Ravenscar Profile" section
2962 in the GDB user manual.
2964 * Guile support was removed.
2966 * New features in the GNU simulator
2968 ** The --map-info flag lists all known core mappings.
2970 ** CFI flashes may be simulated via the "cfi" device.
2972 *** Changes in GDB 7.2
2974 * Shared library support for remote targets by default
2976 When GDB is configured for a generic, non-OS specific target, like
2977 for example, --target=arm-eabi or one of the many *-*-elf targets,
2978 GDB now queries remote stubs for loaded shared libraries using the
2979 `qXfer:libraries:read' packet. Previously, shared library support
2980 was always disabled for such configurations.
2984 ** Argument Dependent Lookup (ADL)
2986 In C++ ADL lookup directs function search to the namespaces of its
2987 arguments even if the namespace has not been imported.
2997 Here the compiler will search for `foo' in the namespace of 'b'
2998 and find A::foo. GDB now supports this. This construct is commonly
2999 used in the Standard Template Library for operators.
3001 ** Improved User Defined Operator Support
3003 In addition to member operators, GDB now supports lookup of operators
3004 defined in a namespace and imported with a `using' directive, operators
3005 defined in the global scope, operators imported implicitly from an
3006 anonymous namespace, and the ADL operators mentioned in the previous
3008 GDB now also supports proper overload resolution for all the previously
3009 mentioned flavors of operators.
3011 ** static const class members
3013 Printing of static const class members that are initialized in the
3014 class definition has been fixed.
3016 * Windows Thread Information Block access.
3018 On Windows targets, GDB now supports displaying the Windows Thread
3019 Information Block (TIB) structure. This structure is visible either
3020 by using the new command `info w32 thread-information-block' or, by
3021 dereferencing the new convenience variable named `$_tlb', a
3022 thread-specific pointer to the TIB. This feature is also supported
3023 when remote debugging using GDBserver.
3025 * Static tracepoints
3027 Static tracepoints are calls in the user program into a tracing
3028 library. One such library is a port of the LTTng kernel tracer to
3029 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3030 When debugging with GDBserver, GDB now supports combining the GDB
3031 tracepoint machinery with such libraries. For example: the user can
3032 use GDB to probe a static tracepoint marker (a call from the user
3033 program into the tracing library) with the new "strace" command (see
3034 "New commands" below). This creates a "static tracepoint" in the
3035 breakpoint list, that can be manipulated with the same feature set
3036 as fast and regular tracepoints. E.g., collect registers, local and
3037 global variables, collect trace state variables, and define
3038 tracepoint conditions. In addition, the user can collect extra
3039 static tracepoint marker specific data, by collecting the new
3040 $_sdata internal variable. When analyzing the trace buffer, you can
3041 inspect $_sdata like any other variable available to GDB. For more
3042 information, see the "Tracepoints" chapter in GDB user manual. New
3043 remote packets have been defined to support static tracepoints, see
3044 the "New remote packets" section below.
3046 * Better reconstruction of tracepoints after disconnected tracing
3048 GDB will attempt to download the original source form of tracepoint
3049 definitions when starting a trace run, and then will upload these
3050 upon reconnection to the target, resulting in a more accurate
3051 reconstruction of the tracepoints that are in use on the target.
3055 You can now exercise direct control over the ways that GDB can
3056 affect your program. For instance, you can disallow the setting of
3057 breakpoints, so that the program can run continuously (assuming
3058 non-stop mode). In addition, the "observer" variable is available
3059 to switch all of the different controls; in observer mode, GDB
3060 cannot affect the target's behavior at all, which is useful for
3061 tasks like diagnosing live systems in the field.
3063 * The new convenience variable $_thread holds the number of the
3066 * New remote packets
3070 Return the address of the Windows Thread Information Block of a given thread.
3074 In response to several of the tracepoint packets, the target may now
3075 also respond with a number of intermediate `qRelocInsn' request
3076 packets before the final result packet, to have GDB handle
3077 relocating an instruction to execute at a different address. This
3078 is particularly useful for stubs that support fast tracepoints. GDB
3079 reports support for this feature in the qSupported packet.
3083 List static tracepoint markers in the target program.
3087 List static tracepoint markers at a given address in the target
3090 qXfer:statictrace:read
3092 Read the static trace data collected (by a `collect $_sdata'
3093 tracepoint action). The remote stub reports support for this packet
3094 to gdb's qSupported query.
3098 Send the current settings of GDB's permission flags.
3102 Send part of the source (textual) form of a tracepoint definition,
3103 which includes location, conditional, and action list.
3105 * The source command now accepts a -s option to force searching for the
3106 script in the source search path even if the script name specifies
3109 * New features in the GDB remote stub, GDBserver
3111 - GDBserver now support tracepoints (including fast tracepoints, and
3112 static tracepoints). The feature is currently supported by the
3113 i386-linux and amd64-linux builds. See the "Tracepoints support
3114 in gdbserver" section in the manual for more information.
3116 GDBserver JIT compiles the tracepoint's conditional agent
3117 expression bytecode into native code whenever possible for low
3118 overhead dynamic tracepoints conditionals. For such tracepoints,
3119 an expression that examines program state is evaluated when the
3120 tracepoint is reached, in order to determine whether to capture
3121 trace data. If the condition is simple and false, processing the
3122 tracepoint finishes very quickly and no data is gathered.
3124 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3125 for static tracepoints support.
3127 - GDBserver now supports x86_64 Windows 64-bit debugging.
3129 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3130 it understands register description.
3132 * The --batch flag now disables pagination and queries.
3134 * X86 general purpose registers
3136 GDB now supports reading/writing byte, word and double-word x86
3137 general purpose registers directly. This means you can use, say,
3138 $ah or $ax to refer, respectively, to the byte register AH and
3139 16-bit word register AX that are actually portions of the 32-bit
3140 register EAX or 64-bit register RAX.
3142 * The `commands' command now accepts a range of breakpoints to modify.
3143 A plain `commands' following a command that creates multiple
3144 breakpoints affects all the breakpoints set by that command. This
3145 applies to breakpoints set by `rbreak', and also applies when a
3146 single `break' command creates multiple breakpoints (e.g.,
3147 breakpoints on overloaded c++ functions).
3149 * The `rbreak' command now accepts a filename specification as part of
3150 its argument, limiting the functions selected by the regex to those
3151 in the specified file.
3153 * Support for remote debugging Windows and SymbianOS shared libraries
3154 from Unix hosts has been improved. Non Windows GDB builds now can
3155 understand target reported file names that follow MS-DOS based file
3156 system semantics, such as file names that include drive letters and
3157 use the backslash character as directory separator. This makes it
3158 possible to transparently use the "set sysroot" and "set
3159 solib-search-path" on Unix hosts to point as host copies of the
3160 target's shared libraries. See the new command "set
3161 target-file-system-kind" described below, and the "Commands to
3162 specify files" section in the user manual for more information.
3166 eval template, expressions...
3167 Convert the values of one or more expressions under the control
3168 of the string template to a command line, and call it.
3170 set target-file-system-kind unix|dos-based|auto
3171 show target-file-system-kind
3172 Set or show the assumed file system kind for target reported file
3175 save breakpoints <filename>
3176 Save all current breakpoint definitions to a file suitable for use
3177 in a later debugging session. To read the saved breakpoint
3178 definitions, use the `source' command.
3180 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3183 info static-tracepoint-markers
3184 Display information about static tracepoint markers in the target.
3186 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3187 Define a static tracepoint by probing a marker at the given
3188 function, line, address, or marker ID.
3192 Enable and disable observer mode.
3194 set may-write-registers on|off
3195 set may-write-memory on|off
3196 set may-insert-breakpoints on|off
3197 set may-insert-tracepoints on|off
3198 set may-insert-fast-tracepoints on|off
3199 set may-interrupt on|off
3200 Set individual permissions for GDB effects on the target. Note that
3201 some of these settings can have undesirable or surprising
3202 consequences, particularly when changed in the middle of a session.
3203 For instance, disabling the writing of memory can prevent
3204 breakpoints from being inserted, cause single-stepping to fail, or
3205 even crash your program, if you disable after breakpoints have been
3206 inserted. However, GDB should not crash.
3208 set record memory-query on|off
3209 show record memory-query
3210 Control whether to stop the inferior if memory changes caused
3211 by an instruction cannot be recorded.
3216 The disassemble command now supports "start,+length" form of two arguments.
3220 ** GDB now provides a new directory location, called the python directory,
3221 where Python scripts written for GDB can be installed. The location
3222 of that directory is <data-directory>/python, where <data-directory>
3223 is the GDB data directory. For more details, see section `Scripting
3224 GDB using Python' in the manual.
3226 ** The GDB Python API now has access to breakpoints, symbols, symbol
3227 tables, program spaces, inferiors, threads and frame's code blocks.
3228 Additionally, GDB Parameters can now be created from the API, and
3229 manipulated via set/show in the CLI.
3231 ** New functions gdb.target_charset, gdb.target_wide_charset,
3232 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3234 ** New exception gdb.GdbError.
3236 ** Pretty-printers are now also looked up in the current program space.
3238 ** Pretty-printers can now be individually enabled and disabled.
3240 ** GDB now looks for names of Python scripts to auto-load in a
3241 special section named `.debug_gdb_scripts', in addition to looking
3242 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3244 * Tracepoint actions were unified with breakpoint commands. In particular,
3245 there are no longer differences in "info break" output for breakpoints and
3246 tracepoints and the "commands" command can be used for both tracepoints and
3247 regular breakpoints.
3251 ARM Symbian arm*-*-symbianelf*
3253 * D language support.
3254 GDB now supports debugging programs written in the D programming
3257 * GDB now supports the extended ptrace interface for PowerPC which is
3258 available since Linux kernel version 2.6.34. This automatically enables
3259 any hardware breakpoints and additional hardware watchpoints available in
3260 the processor. The old ptrace interface exposes just one hardware
3261 watchpoint and no hardware breakpoints.
3263 * GDB is now able to use the Data Value Compare (DVC) register available on
3264 embedded PowerPC processors to implement in hardware simple watchpoint
3265 conditions of the form:
3267 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3269 This works in native GDB running on Linux kernels with the extended ptrace
3270 interface mentioned above.
3272 *** Changes in GDB 7.1
3276 ** Namespace Support
3278 GDB now supports importing of namespaces in C++. This enables the
3279 user to inspect variables from imported namespaces. Support for
3280 namepace aliasing has also been added. So, if a namespace is
3281 aliased in the current scope (e.g. namepace C=A; ) the user can
3282 print variables using the alias (e.g. (gdb) print C::x).
3286 All known bugs relating to the printing of virtual base class were
3287 fixed. It is now possible to call overloaded static methods using a
3292 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3293 and reinterpret_cast<> are now handled by the C++ expression parser.
3297 Xilinx MicroBlaze microblaze-*-*
3302 Xilinx MicroBlaze microblaze
3305 * Multi-program debugging.
3307 GDB now has support for multi-program (a.k.a. multi-executable or
3308 multi-exec) debugging. This allows for debugging multiple inferiors
3309 simultaneously each running a different program under the same GDB
3310 session. See "Debugging Multiple Inferiors and Programs" in the
3311 manual for more information. This implied some user visible changes
3312 in the multi-inferior support. For example, "info inferiors" now
3313 lists inferiors that are not running yet or that have exited
3314 already. See also "New commands" and "New options" below.
3316 * New tracing features
3318 GDB's tracepoint facility now includes several new features:
3320 ** Trace state variables
3322 GDB tracepoints now include support for trace state variables, which
3323 are variables managed by the target agent during a tracing
3324 experiment. They are useful for tracepoints that trigger each
3325 other, so for instance one tracepoint can count hits in a variable,
3326 and then a second tracepoint has a condition that is true when the
3327 count reaches a particular value. Trace state variables share the
3328 $-syntax of GDB convenience variables, and can appear in both
3329 tracepoint actions and condition expressions. Use the "tvariable"
3330 command to create, and "info tvariables" to view; see "Trace State
3331 Variables" in the manual for more detail.
3335 GDB now includes an option for defining fast tracepoints, which
3336 targets may implement more efficiently, such as by installing a jump
3337 into the target agent rather than a trap instruction. The resulting
3338 speedup can be by two orders of magnitude or more, although the
3339 tradeoff is that some program locations on some target architectures
3340 might not allow fast tracepoint installation, for instance if the
3341 instruction to be replaced is shorter than the jump. To request a
3342 fast tracepoint, use the "ftrace" command, with syntax identical to
3343 the regular trace command.
3345 ** Disconnected tracing
3347 It is now possible to detach GDB from the target while it is running
3348 a trace experiment, then reconnect later to see how the experiment
3349 is going. In addition, a new variable disconnected-tracing lets you
3350 tell the target agent whether to continue running a trace if the
3351 connection is lost unexpectedly.
3355 GDB now has the ability to save the trace buffer into a file, and
3356 then use that file as a target, similarly to you can do with
3357 corefiles. You can select trace frames, print data that was
3358 collected in them, and use tstatus to display the state of the
3359 tracing run at the moment that it was saved. To create a trace
3360 file, use "tsave <filename>", and to use it, do "target tfile
3363 ** Circular trace buffer
3365 You can ask the target agent to handle the trace buffer as a
3366 circular buffer, discarding the oldest trace frames to make room for
3367 newer ones, by setting circular-trace-buffer to on. This feature may
3368 not be available for all target agents.
3373 The disassemble command, when invoked with two arguments, now requires
3374 the arguments to be comma-separated.
3377 The info variables command now displays variable definitions. Files
3378 which only declare a variable are not shown.
3381 The source command is now capable of sourcing Python scripts.
3382 This feature is dependent on the debugger being build with Python
3385 Related to this enhancement is also the introduction of a new command
3386 "set script-extension" (see below).
3388 * New commands (for set/show, see "New options" below)
3390 record save [<FILENAME>]
3391 Save a file (in core file format) containing the process record
3392 execution log for replay debugging at a later time.
3394 record restore <FILENAME>
3395 Restore the process record execution log that was saved at an
3396 earlier time, for replay debugging.
3398 add-inferior [-copies <N>] [-exec <FILENAME>]
3401 clone-inferior [-copies <N>] [ID]
3402 Make a new inferior ready to execute the same program another
3403 inferior has loaded.
3408 maint info program-spaces
3409 List the program spaces loaded into GDB.
3411 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3412 show remote interrupt-sequence
3413 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3414 as the sequence to the remote target in order to interrupt the execution.
3415 Ctrl-C is a default. Some system prefers BREAK which is high level of
3416 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3417 Magic SysRq g. It is BREAK signal and character 'g'.
3419 set remote interrupt-on-connect [on | off]
3420 show remote interrupt-on-connect
3421 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3422 remote target when gdb connects to it. This is needed when you debug
3425 set remotebreak [on | off]
3427 Deprecated. Use "set/show remote interrupt-sequence" instead.
3429 tvariable $NAME [ = EXP ]
3430 Create or modify a trace state variable.
3433 List trace state variables and their values.
3435 delete tvariable $NAME ...
3436 Delete one or more trace state variables.
3439 Evaluate the given expressions without collecting anything into the
3440 trace buffer. (Valid in tracepoint actions only.)
3442 ftrace FN / FILE:LINE / *ADDR
3443 Define a fast tracepoint at the given function, line, or address.
3445 * New expression syntax
3447 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3448 GDB now parses 0b101010 identically with 42.
3452 set follow-exec-mode new|same
3453 show follow-exec-mode
3454 Control whether GDB reuses the same inferior across an exec call or
3455 creates a new one. This is useful to be able to restart the old
3456 executable after the inferior having done an exec call.
3458 set default-collect EXPR, ...
3459 show default-collect
3460 Define a list of expressions to be collected at each tracepoint.
3461 This is a useful way to ensure essential items are not overlooked,
3462 such as registers or a critical global variable.
3464 set disconnected-tracing
3465 show disconnected-tracing
3466 If set to 1, the target is instructed to continue tracing if it
3467 loses its connection to GDB. If 0, the target is to stop tracing
3470 set circular-trace-buffer
3471 show circular-trace-buffer
3472 If set to on, the target is instructed to use a circular trace buffer
3473 and discard the oldest trace frames instead of stopping the trace due
3474 to a full trace buffer. If set to off, the trace stops when the buffer
3475 fills up. Some targets may not support this.
3477 set script-extension off|soft|strict
3478 show script-extension
3479 If set to "off", the debugger does not perform any script language
3480 recognition, and all sourced files are assumed to be GDB scripts.
3481 If set to "soft" (the default), files are sourced according to
3482 filename extension, falling back to GDB scripts if the first
3484 If set to "strict", files are sourced according to filename extension.
3486 set ada trust-PAD-over-XVS on|off
3487 show ada trust-PAD-over-XVS
3488 If off, activate a workaround against a bug in the debugging information
3489 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3490 the GCC sources for more information about the GNAT encoding and
3491 PAD types in particular). It is always safe to set this option to
3492 off, but this introduces a slight performance penalty. The default
3495 * Python API Improvements
3497 ** GDB provides the new class gdb.LazyString. This is useful in
3498 some pretty-printing cases. The new method gdb.Value.lazy_string
3499 provides a simple way to create objects of this type.
3501 ** The fields returned by gdb.Type.fields now have an
3502 `is_base_class' attribute.
3504 ** The new method gdb.Type.range returns the range of an array type.
3506 ** The new method gdb.parse_and_eval can be used to parse and
3507 evaluate an expression.
3509 * New remote packets
3512 Define a trace state variable.
3515 Get the current value of a trace state variable.
3518 Set desired tracing behavior upon disconnection.
3521 Set the trace buffer to be linear or circular.
3524 Get data about the tracepoints currently in use.
3528 Process record now works correctly with hardware watchpoints.
3530 Multiple bug fixes have been made to the mips-irix port, making it
3531 much more reliable. In particular:
3532 - Debugging threaded applications is now possible again. Previously,
3533 GDB would hang while starting the program, or while waiting for
3534 the program to stop at a breakpoint.
3535 - Attaching to a running process no longer hangs.
3536 - An error occurring while loading a core file has been fixed.
3537 - Changing the value of the PC register now works again. This fixes
3538 problems observed when using the "jump" command, or when calling
3539 a function from GDB, or even when assigning a new value to $pc.
3540 - With the "finish" and "return" commands, the return value for functions
3541 returning a small array is now correctly printed.
3542 - It is now possible to break on shared library code which gets executed
3543 during a shared library init phase (code executed while executing
3544 their .init section). Previously, the breakpoint would have no effect.
3545 - GDB is now able to backtrace through the signal handler for
3546 non-threaded programs.
3548 PIE (Position Independent Executable) programs debugging is now supported.
3549 This includes debugging execution of PIC (Position Independent Code) shared
3550 libraries although for that, it should be possible to run such libraries as an
3553 *** Changes in GDB 7.0
3555 * GDB now has an interface for JIT compilation. Applications that
3556 dynamically generate code can create symbol files in memory and register
3557 them with GDB. For users, the feature should work transparently, and
3558 for JIT developers, the interface is documented in the GDB manual in the
3559 "JIT Compilation Interface" chapter.
3561 * Tracepoints may now be conditional. The syntax is as for
3562 breakpoints; either an "if" clause appended to the "trace" command,
3563 or the "condition" command is available. GDB sends the condition to
3564 the target for evaluation using the same bytecode format as is used
3565 for tracepoint actions.
3567 * The disassemble command now supports: an optional /r modifier, print the
3568 raw instructions in hex as well as in symbolic form, and an optional /m
3569 modifier to print mixed source+assembly.
3571 * Process record and replay
3573 In a architecture environment that supports ``process record and
3574 replay'', ``process record and replay'' target can record a log of
3575 the process execution, and replay it with both forward and reverse
3578 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3579 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3580 set execution-direction {forward|reverse}, for targets that support
3583 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3584 feature is available with a native GDB running on kernel version
3587 * GDB now has support for multi-byte and wide character sets on the
3588 target. Strings whose character type is wchar_t, char16_t, or
3589 char32_t are now correctly printed. GDB supports wide- and unicode-
3590 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3591 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3592 `printf'. This feature requires iconv to work properly; if your
3593 system does not have a working iconv, GDB can use GNU libiconv. See
3594 the installation instructions for more information.
3596 * GDB now supports automatic retrieval of shared library files from
3597 remote targets. To use this feature, specify a system root that begins
3598 with the `remote:' prefix, either via the `set sysroot' command or via
3599 the `--with-sysroot' configure-time option.
3601 * "info sharedlibrary" now takes an optional regex of libraries to show,
3602 and it now reports if a shared library has no debugging information.
3604 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3605 now complete on file names.
3607 * When completing in expressions, gdb will attempt to limit
3608 completions to allowable structure or union fields, where appropriate.
3609 For instance, consider:
3611 # struct example { int f1; double f2; };
3612 # struct example variable;
3615 If the user types TAB at the end of this command line, the available
3616 completions will be "f1" and "f2".
3618 * Inlined functions are now supported. They show up in backtraces, and
3619 the "step", "next", and "finish" commands handle them automatically.
3621 * GDB now supports the token-splicing (##) and stringification (#)
3622 operators when expanding macros. It also supports variable-arity
3625 * GDB now supports inspecting extra signal information, exported by
3626 the new $_siginfo convenience variable. The feature is currently
3627 implemented on linux ARM, i386 and amd64.
3629 * GDB can now display the VFP floating point registers and NEON vector
3630 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3631 can provide these registers (requires Linux 2.6.30 or later). Remote
3632 and simulator targets may also provide them.
3634 * New remote packets
3637 Search memory for a sequence of bytes.
3640 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3641 operation over reliable transport links. Use of this packet is
3642 controlled by the `set remote noack-packet' command.
3645 Kill the process with the specified process ID. Use this in preference
3646 to `k' when multiprocess protocol extensions are supported.
3649 Obtains additional operating system information
3653 Read or write additional signal information.
3655 * Removed remote protocol undocumented extension
3657 An undocumented extension to the remote protocol's `S' stop reply
3658 packet that permited the stub to pass a process id was removed.
3659 Remote servers should use the `T' stop reply packet instead.
3661 * GDB now supports multiple function calling conventions according to the
3662 DWARF-2 DW_AT_calling_convention function attribute.
3664 * The SH target utilizes the aforementioned change to distinguish between gcc
3665 and Renesas calling convention. It also adds the new CLI commands
3666 `set/show sh calling-convention'.
3668 * GDB can now read compressed debug sections, as produced by GNU gold
3669 with the --compress-debug-sections=zlib flag.
3671 * 64-bit core files are now supported on AIX.
3673 * Thread switching is now supported on Tru64.
3675 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3676 which will be allocated using malloc later in program execution.
3678 * The qXfer:libraries:read remote procotol packet now allows passing a
3679 list of section offsets.
3681 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3682 conditions handling signals delivered during attach or thread creation
3683 have also been fixed.
3685 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3686 From the user's standpoint, all unqualified instances of True and False
3687 are treated as the standard definitions, regardless of context.
3689 * GDB now parses C++ symbol and type names more flexibly. For
3692 template<typename T> class C { };
3695 GDB will now correctly handle all of:
3697 ptype C<char const *>
3698 ptype C<char const*>
3699 ptype C<const char *>
3700 ptype C<const char*>
3702 * New features in the GDB remote stub, gdbserver
3704 - The "--wrapper" command-line argument tells gdbserver to use a
3705 wrapper program to launch programs for debugging.
3707 - On PowerPC and S/390 targets, it is now possible to use a single
3708 gdbserver executable to debug both 32-bit and 64-bit programs.
3709 (This requires gdbserver itself to be built as a 64-bit executable.)
3711 - gdbserver uses the new noack protocol mode for TCP connections to
3712 reduce communications latency, if also supported and enabled in GDB.
3714 - Support for the sparc64-linux-gnu target is now included in
3717 - The amd64-linux build of gdbserver now supports debugging both
3718 32-bit and 64-bit programs.
3720 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3721 now support hardware watchpoints, and will use them automatically
3726 GDB now has support for scripting using Python. Whether this is
3727 available is determined at configure time.
3729 New GDB commands can now be written in Python.
3731 * Ada tasking support
3733 Ada tasks can now be inspected in GDB. The following commands have
3737 Print the list of Ada tasks.
3739 Print detailed information about task number N.
3741 Print the task number of the current task.
3743 Switch the context of debugging to task number N.
3745 * Support for user-defined prefixed commands. The "define" command can
3746 add new commands to existing prefixes, e.g. "target".
3748 * Multi-inferior, multi-process debugging.
3750 GDB now has generalized support for multi-inferior debugging. See
3751 "Debugging Multiple Inferiors" in the manual for more information.
3752 Although availability still depends on target support, the command
3753 set is more uniform now. The GNU/Linux specific multi-forks support
3754 has been migrated to this new framework. This implied some user
3755 visible changes; see "New commands" and also "Removed commands"
3758 * Target descriptions can now describe the target OS ABI. See the
3759 "Target Description Format" section in the user manual for more
3762 * Target descriptions can now describe "compatible" architectures
3763 to indicate that the target can execute applications for a different
3764 architecture in addition to those for the main target architecture.
3765 See the "Target Description Format" section in the user manual for
3768 * Multi-architecture debugging.
3770 GDB now includes general supports for debugging applications on
3771 hybrid systems that use more than one single processor architecture
3772 at the same time. Each such hybrid architecture still requires
3773 specific support to be added. The only hybrid architecture supported
3774 in this version of GDB is the Cell Broadband Engine.
3776 * GDB now supports integrated debugging of Cell/B.E. applications that
3777 use both the PPU and SPU architectures. To enable support for hybrid
3778 Cell/B.E. debugging, you need to configure GDB to support both the
3779 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3780 --enable-targets configure option.
3782 * Non-stop mode debugging.
3784 For some targets, GDB now supports an optional mode of operation in
3785 which you can examine stopped threads while other threads continue
3786 to execute freely. This is referred to as non-stop mode, with the
3787 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3788 section in the user manual for more information.
3790 To be able to support remote non-stop debugging, a remote stub needs
3791 to implement the non-stop mode remote protocol extensions, as
3792 described in the "Remote Non-Stop" section of the user manual. The
3793 GDB remote stub, gdbserver, has been adjusted to support these
3794 extensions on linux targets.
3796 * New commands (for set/show, see "New options" below)
3798 catch syscall [NAME(S) | NUMBER(S)]
3799 Catch system calls. Arguments, which should be names of system
3800 calls or their numbers, mean catch only those syscalls. Without
3801 arguments, every syscall will be caught. When the inferior issues
3802 any of the specified syscalls, GDB will stop and announce the system
3803 call, both when it is called and when its call returns. This
3804 feature is currently available with a native GDB running on the
3805 Linux Kernel, under the following architectures: x86, x86_64,
3806 PowerPC and PowerPC64.
3808 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3810 Search memory for a sequence of bytes.
3812 maint set python print-stack
3813 maint show python print-stack
3814 Show a stack trace when an error is encountered in a Python script.
3817 Invoke CODE by passing it to the Python interpreter.
3822 These allow macros to be defined, undefined, and listed
3826 Show operating system information about processes.
3829 List the inferiors currently under GDB's control.
3832 Switch focus to inferior number NUM.
3835 Detach from inferior number NUM.
3838 Kill inferior number NUM.
3842 set spu stop-on-load
3843 show spu stop-on-load
3844 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3846 set spu auto-flush-cache
3847 show spu auto-flush-cache
3848 Control whether to automatically flush the software-managed cache
3849 during Cell/B.E. debugging.
3851 set sh calling-convention
3852 show sh calling-convention
3853 Control the calling convention used when calling SH target functions.
3856 show debug timestamp
3857 Control display of timestamps with GDB debugging output.
3859 set disassemble-next-line
3860 show disassemble-next-line
3861 Control display of disassembled source lines or instructions when
3864 set remote noack-packet
3865 show remote noack-packet
3866 Set/show the use of remote protocol QStartNoAckMode packet. See above
3867 under "New remote packets."
3869 set remote query-attached-packet
3870 show remote query-attached-packet
3871 Control use of remote protocol `qAttached' (query-attached) packet.
3873 set remote read-siginfo-object
3874 show remote read-siginfo-object
3875 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3878 set remote write-siginfo-object
3879 show remote write-siginfo-object
3880 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3883 set remote reverse-continue
3884 show remote reverse-continue
3885 Control use of remote protocol 'bc' (reverse-continue) packet.
3887 set remote reverse-step
3888 show remote reverse-step
3889 Control use of remote protocol 'bs' (reverse-step) packet.
3891 set displaced-stepping
3892 show displaced-stepping
3893 Control displaced stepping mode. Displaced stepping is a way to
3894 single-step over breakpoints without removing them from the debuggee.
3895 Also known as "out-of-line single-stepping".
3898 show debug displaced
3899 Control display of debugging info for displaced stepping.
3901 maint set internal-error
3902 maint show internal-error
3903 Control what GDB does when an internal error is detected.
3905 maint set internal-warning
3906 maint show internal-warning
3907 Control what GDB does when an internal warning is detected.
3912 Use a wrapper program to launch programs for debugging.
3914 set multiple-symbols (all|ask|cancel)
3915 show multiple-symbols
3916 The value of this variable can be changed to adjust the debugger behavior
3917 when an expression or a breakpoint location contains an ambiguous symbol
3918 name (an overloaded function name, for instance).
3920 set breakpoint always-inserted
3921 show breakpoint always-inserted
3922 Keep breakpoints always inserted in the target, as opposed to inserting
3923 them when resuming the target, and removing them when the target stops.
3924 This option can improve debugger performance on slow remote targets.
3926 set arm fallback-mode (arm|thumb|auto)
3927 show arm fallback-mode
3928 set arm force-mode (arm|thumb|auto)
3930 These commands control how ARM GDB determines whether instructions
3931 are ARM or Thumb. The default for both settings is auto, which uses
3932 the current CPSR value for instructions without symbols; previous
3933 versions of GDB behaved as if "set arm fallback-mode arm".
3935 set disable-randomization
3936 show disable-randomization
3937 Standalone programs run with the virtual address space randomization enabled
3938 by default on some platforms. This option keeps the addresses stable across
3939 multiple debugging sessions.
3943 Control whether other threads are stopped or not when some thread hits
3948 Requests that asynchronous execution is enabled in the target, if available.
3949 In this case, it's possible to resume target in the background, and interact
3950 with GDB while the target is running. "show target-async" displays the
3951 current state of asynchronous execution of the target.
3953 set target-wide-charset
3954 show target-wide-charset
3955 The target-wide-charset is the name of the character set that GDB
3956 uses when printing characters whose type is wchar_t.
3958 set tcp auto-retry (on|off)
3960 set tcp connect-timeout
3961 show tcp connect-timeout
3962 These commands allow GDB to retry failed TCP connections to a remote stub
3963 with a specified timeout period; this is useful if the stub is launched
3964 in parallel with GDB but may not be ready to accept connections immediately.
3966 set libthread-db-search-path
3967 show libthread-db-search-path
3968 Control list of directories which GDB will search for appropriate
3971 set schedule-multiple (on|off)
3972 show schedule-multiple
3973 Allow GDB to resume all threads of all processes or only threads of
3974 the current process.
3978 Use more aggressive caching for accesses to the stack. This improves
3979 performance of remote debugging (particularly backtraces) without
3980 affecting correctness.
3982 set interactive-mode (on|off|auto)
3983 show interactive-mode
3984 Control whether GDB runs in interactive mode (on) or not (off).
3985 When in interactive mode, GDB waits for the user to answer all
3986 queries. Otherwise, GDB does not wait and assumes the default
3987 answer. When set to auto (the default), GDB determines which
3988 mode to use based on the stdin settings.
3993 For program forks, this is replaced by the new more generic `info
3994 inferiors' command. To list checkpoints, you can still use the
3995 `info checkpoints' command, which was an alias for the `info forks'
3999 Replaced by the new `inferior' command. To switch between
4000 checkpoints, you can still use the `restart' command, which was an
4001 alias for the `fork' command.
4004 This is removed, since some targets don't have a notion of
4005 processes. To switch between processes, you can still use the
4006 `inferior' command using GDB's own inferior number.
4009 For program forks, this is replaced by the new more generic `kill
4010 inferior' command. To delete a checkpoint, you can still use the
4011 `delete checkpoint' command, which was an alias for the `delete
4015 For program forks, this is replaced by the new more generic `detach
4016 inferior' command. To detach a checkpoint, you can still use the
4017 `detach checkpoint' command, which was an alias for the `detach
4020 * New native configurations
4022 x86/x86_64 Darwin i[34567]86-*-darwin*
4024 x86_64 MinGW x86_64-*-mingw*
4028 Lattice Mico32 lm32-*
4029 x86 DICOS i[34567]86-*-dicos*
4030 x86_64 DICOS x86_64-*-dicos*
4033 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4034 (mingw32ce) debugging.
4040 These commands were actually not implemented on any target.
4042 *** Changes in GDB 6.8
4044 * New native configurations
4046 NetBSD/hppa hppa*-*netbsd*
4047 Xtensa GNU/Linux xtensa*-*-linux*
4051 NetBSD/hppa hppa*-*-netbsd*
4052 Xtensa GNU/Lunux xtensa*-*-linux*
4054 * Change in command line behavior -- corefiles vs. process ids.
4056 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4057 attaching to process NUMBER fails, GDB no longer attempts to open a
4058 core file named NUMBER. Attaching to a program using the -c option
4059 is no longer supported. Instead, use the '-p' or '--pid' options.
4061 * GDB can now be built as a native debugger for debugging Windows x86
4062 (mingw32) Portable Executable (PE) programs.
4064 * Pending breakpoints no longer change their number when their address
4067 * GDB now supports breakpoints with multiple locations,
4068 including breakpoints on C++ constructors, inside C++ templates,
4069 and in inlined functions.
4071 * GDB's ability to debug optimized code has been improved. GDB more
4072 accurately identifies function bodies and lexical blocks that occupy
4073 more than one contiguous range of addresses.
4075 * Target descriptions can now describe registers for PowerPC.
4077 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4078 registers on PowerPC targets.
4080 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4081 targets even when the libthread_db library is not available.
4083 * The GDB remote stub, gdbserver, now supports the new file transfer
4084 commands (remote put, remote get, and remote delete).
4086 * The GDB remote stub, gdbserver, now supports run and attach in
4087 extended-remote mode.
4089 * hppa*64*-*-hpux11* target broken
4090 The debugger is unable to start a program and fails with the following
4091 error: "Error trying to get information about dynamic linker".
4092 The gdb-6.7 release is also affected.
4094 * GDB now supports the --enable-targets= configure option to allow
4095 building a single GDB executable that supports multiple remote
4096 target architectures.
4098 * GDB now supports debugging C and C++ programs which use the
4099 Decimal Floating Point extension. In addition, the PowerPC target
4100 now has a set of pseudo-registers to inspect decimal float values
4101 stored in two consecutive float registers.
4103 * The -break-insert MI command can optionally create pending
4106 * Improved support for debugging Ada
4107 Many improvements to the Ada language support have been made. These
4109 - Better support for Ada2005 interface types
4110 - Improved handling of arrays and slices in general
4111 - Better support for Taft-amendment types
4112 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4114 - Improved command completion in Ada
4117 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4122 set print frame-arguments (all|scalars|none)
4123 show print frame-arguments
4124 The value of this variable can be changed to control which argument
4125 values should be printed by the debugger when displaying a frame.
4130 Transfer files to and from a remote target, and delete remote files.
4137 Transfer files to and from a remote target, and delete remote files.
4139 * New remote packets
4146 Open, close, read, write, and delete files on the remote system.
4149 Attach to an existing process on the remote system, in extended-remote
4153 Run a new process on the remote system, in extended-remote mode.
4155 *** Changes in GDB 6.7
4157 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4158 bfd, libiberty and opcodes, as revealed by static analysis donated by
4159 Coverity, Inc. (http://scan.coverity.com).
4161 * When looking up multiply-defined global symbols, GDB will now prefer the
4162 symbol definition in the current shared library if it was built using the
4163 -Bsymbolic linker option.
4165 * When the Text User Interface (TUI) is not configured, GDB will now
4166 recognize the -tui command-line option and print a message that the TUI
4169 * The GDB remote stub, gdbserver, now has lower overhead for high
4170 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4172 * GDB for MIPS targets now autodetects whether a remote target provides
4173 32-bit or 64-bit register values.
4175 * Support for C++ member pointers has been improved.
4177 * GDB now understands XML target descriptions, which specify the
4178 target's overall architecture. GDB can read a description from
4179 a local file or over the remote serial protocol.
4181 * Vectors of single-byte data use a new integer type which is not
4182 automatically displayed as character or string data.
4184 * The /s format now works with the print command. It displays
4185 arrays of single-byte integers and pointers to single-byte integers
4188 * Target descriptions can now describe target-specific registers,
4189 for architectures which have implemented the support (currently
4190 only ARM, M68K, and MIPS).
4192 * GDB and the GDB remote stub, gdbserver, now support the XScale
4195 * The GDB remote stub, gdbserver, has been updated to support
4196 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4197 has been rewritten to use the standard GDB remote protocol.
4199 * GDB can now step into C++ functions which are called through thunks.
4201 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4203 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4204 layout. It also supports a TextSeg= and DataSeg= response when only
4205 segment base addresses (rather than offsets) are available.
4207 * The /i format now outputs any trailing branch delay slot instructions
4208 immediately following the last instruction within the count specified.
4210 * The GDB remote protocol "T" stop reply packet now supports a
4211 "library" response. Combined with the new "qXfer:libraries:read"
4212 packet, this response allows GDB to debug shared libraries on targets
4213 where the operating system manages the list of loaded libraries (e.g.
4214 Windows and SymbianOS).
4216 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4217 (DLLs) on Windows and Windows CE targets.
4219 * GDB now supports a faster verification that a .debug file matches its binary
4220 according to its build-id signature, if the signature is present.
4226 Enable or disable hardware flow control (RTS/CTS) on the serial port
4227 when debugging using remote targets.
4229 set mem inaccessible-by-default
4230 show mem inaccessible-by-default
4231 If the target supplies a memory map, for instance via the remote
4232 protocol's "qXfer:memory-map:read" packet, setting this variable
4233 prevents GDB from accessing memory outside the memory map. This
4234 is useful for targets with memory mapped registers or which react
4235 badly to accesses of unmapped address space.
4237 set breakpoint auto-hw
4238 show breakpoint auto-hw
4239 If the target supplies a memory map, for instance via the remote
4240 protocol's "qXfer:memory-map:read" packet, setting this variable
4241 lets GDB use hardware breakpoints automatically for memory regions
4242 where it can not use software breakpoints. This covers both the
4243 "break" command and internal breakpoints used for other commands
4244 including "next" and "finish".
4247 catch exception unhandled
4248 Stop the program execution when Ada exceptions are raised.
4251 Stop the program execution when an Ada assertion failed.
4255 Set an alternate system root for target files. This is a more
4256 general version of "set solib-absolute-prefix", which is now
4257 an alias to "set sysroot".
4260 Provide extended SPU facility status information. This set of
4261 commands is available only when debugging the Cell/B.E. SPU
4264 * New native configurations
4266 OpenBSD/sh sh*-*openbsd*
4269 unset tdesc filename
4271 Use the specified local file as an XML target description, and do
4272 not query the target for its built-in description.
4276 OpenBSD/sh sh*-*-openbsd*
4277 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4278 Toshiba Media Processor mep-elf
4280 * New remote packets
4283 Ignore the specified signals; pass them directly to the debugged program
4284 without stopping other threads or reporting them to GDB.
4286 qXfer:features:read:
4287 Read an XML target description from the target, which describes its
4292 Read or write contents of an spufs file on the target system. These
4293 packets are available only on the Cell/B.E. SPU architecture.
4295 qXfer:libraries:read:
4296 Report the loaded shared libraries. Combined with new "T" packet
4297 response, this packet allows GDB to debug shared libraries on
4298 targets where the operating system manages the list of loaded
4299 libraries (e.g. Windows and SymbianOS).
4303 Support for these obsolete configurations has been removed.
4311 i[34567]86-*-lynxos*
4312 i[34567]86-*-netware*
4313 i[34567]86-*-sco3.2v5*
4314 i[34567]86-*-sco3.2v4*
4316 i[34567]86-*-sysv4.2*
4319 i[34567]86-*-unixware2*
4320 i[34567]86-*-unixware*
4329 * Other removed features
4336 Various m68k-only ROM monitors.
4343 Various Renesas ROM monitors and debugging interfaces for SH and
4348 Support for a Macraigor serial interface to on-chip debugging.
4349 GDB does not directly support the newer parallel or USB
4354 A debug information format. The predecessor to DWARF 2 and
4355 DWARF 3, which are still supported.
4357 Support for the HP aCC compiler on HP-UX/PA-RISC
4359 SOM-encapsulated symbolic debugging information, automatic
4360 invocation of pxdb, and the aCC custom C++ ABI. This does not
4361 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4362 with aCC can still be debugged on an assembly level.
4364 MIPS ".pdr" sections
4366 A MIPS-specific format used to describe stack frame layout
4367 in debugging information.
4371 GDB could work with an older version of Guile to debug
4372 the interpreter and Scheme programs running in it.
4374 set mips stack-arg-size
4375 set mips saved-gpreg-size
4377 Use "set mips abi" to control parameter passing for MIPS.
4379 *** Changes in GDB 6.6
4384 Cell Broadband Engine SPU spu-elf
4386 * GDB can now be configured as a cross-debugger targeting native Windows
4387 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4388 running on a Windows system over TCP/IP to debug Windows programs.
4390 * The GDB remote stub, gdbserver, has been updated to support Windows and
4391 Cygwin debugging. Both single-threaded and multi-threaded programs are
4394 * The "set trust-readonly-sections" command works again. This command was
4395 broken in GDB 6.3, 6.4, and 6.5.
4397 * The "load" command now supports writing to flash memory, if the remote
4398 stub provides the required support.
4400 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4401 longer requires symbolic debug information (e.g. DWARF-2).
4406 unset substitute-path
4407 show substitute-path
4408 Manage a list of substitution rules that GDB uses to rewrite the name
4409 of the directories where the sources are located. This can be useful
4410 for instance when the sources were moved to a different location
4411 between compilation and debugging.
4415 Print each CLI command as it is executed. Each command is prefixed with
4416 a number of `+' symbols representing the nesting depth.
4417 The source command now has a `-v' option to enable the same feature.
4421 The ARM Demon monitor support (RDP protocol, "target rdp").
4423 Kernel Object Display, an embedded debugging feature which only worked with
4424 an obsolete version of Cisco IOS.
4426 The 'set download-write-size' and 'show download-write-size' commands.
4428 * New remote packets
4431 Tell a stub about GDB client features, and request remote target features.
4432 The first feature implemented is PacketSize, which allows the target to
4433 specify the size of packets it can handle - to minimize the number of
4434 packets required and improve performance when connected to a remote
4438 Fetch an OS auxilliary vector from the remote stub. This packet is a
4439 more efficient replacement for qPart:auxv:read.
4441 qXfer:memory-map:read:
4442 Fetch a memory map from the remote stub, including information about
4443 RAM, ROM, and flash memory devices.
4448 Erase and program a flash memory device.
4450 * Removed remote packets
4453 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4454 used it, and only gdbserver implemented it.
4456 *** Changes in GDB 6.5
4460 Renesas M32C/M16C m32c-elf
4462 Morpho Technologies ms1 ms1-elf
4466 init-if-undefined Initialize a convenience variable, but
4467 only if it doesn't already have a value.
4469 The following commands are presently only implemented for native GNU/Linux:
4471 checkpoint Save a snapshot of the program state.
4473 restart <n> Return the program state to a
4474 previously saved state.
4476 info checkpoints List currently saved checkpoints.
4478 delete-checkpoint <n> Delete a previously saved checkpoint.
4480 set|show detach-on-fork Tell gdb whether to detach from a newly
4481 forked process, or to keep debugging it.
4483 info forks List forks of the user program that
4484 are available to be debugged.
4486 fork <n> Switch to debugging one of several
4487 forks of the user program that are
4488 available to be debugged.
4490 delete-fork <n> Delete a fork from the list of forks
4491 that are available to be debugged (and
4492 kill the forked process).
4494 detach-fork <n> Delete a fork from the list of forks
4495 that are available to be debugged (and
4496 allow the process to continue).
4500 Morpho Technologies ms2 ms1-elf
4502 * Improved Windows host support
4504 GDB now builds as a cross debugger hosted on i686-mingw32, including
4505 native console support, and remote communications using either
4506 network sockets or serial ports.
4508 * Improved Modula-2 language support
4510 GDB can now print most types in the Modula-2 syntax. This includes:
4511 basic types, set types, record types, enumerated types, range types,
4512 pointer types and ARRAY types. Procedure var parameters are correctly
4513 printed and hexadecimal addresses and character constants are also
4514 written in the Modula-2 syntax. Best results can be obtained by using
4515 GNU Modula-2 together with the -gdwarf-2 command line option.
4519 The ARM rdi-share module.
4521 The Netware NLM debug server.
4523 *** Changes in GDB 6.4
4525 * New native configurations
4527 OpenBSD/arm arm*-*-openbsd*
4528 OpenBSD/mips64 mips64-*-openbsd*
4532 Morpho Technologies ms1 ms1-elf
4534 * New command line options
4536 --batch-silent As for --batch, but totally silent.
4537 --return-child-result The debugger will exist with the same value
4538 the child (debugged) program exited with.
4539 --eval-command COMMAND, -ex COMMAND
4540 Execute a single GDB CLI command. This may be
4541 specified multiple times and in conjunction
4542 with the --command (-x) option.
4544 * Deprecated commands removed
4546 The following commands, that were deprecated in 2000, have been
4550 set|show arm disassembly-flavor set|show arm disassembler
4551 othernames set arm disassembler
4552 set|show remotedebug set|show debug remote
4553 set|show archdebug set|show debug arch
4554 set|show eventdebug set|show debug event
4557 * New BSD user-level threads support
4559 It is now possible to debug programs using the user-level threads
4560 library on OpenBSD and FreeBSD. Currently supported (target)
4563 FreeBSD/amd64 x86_64-*-freebsd*
4564 FreeBSD/i386 i386-*-freebsd*
4565 OpenBSD/i386 i386-*-openbsd*
4567 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4568 are not yet supported.
4570 * New support for Matsushita MN10300 w/sim added
4571 (Work in progress). mn10300-elf.
4573 * REMOVED configurations and files
4575 VxWorks and the XDR protocol *-*-vxworks
4576 Motorola MCORE mcore-*-*
4577 National Semiconductor NS32000 ns32k-*-*
4579 * New "set print array-indexes" command
4581 After turning this setting "on", GDB prints the index of each element
4582 when displaying arrays. The default is "off" to preserve the previous
4585 * VAX floating point support
4587 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4589 * User-defined command support
4591 In addition to using $arg0..$arg9 for argument passing, it is now possible
4592 to use $argc to determine now many arguments have been passed. See the
4593 section on user-defined commands in the user manual for more information.
4595 *** Changes in GDB 6.3:
4597 * New command line option
4599 GDB now accepts -l followed by a number to set the timeout for remote
4602 * GDB works with GCC -feliminate-dwarf2-dups
4604 GDB now supports a more compact representation of DWARF-2 debug
4605 information using DW_FORM_ref_addr references. These are produced
4606 by GCC with the option -feliminate-dwarf2-dups and also by some
4607 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4608 to use -feliminate-dwarf2-dups.
4610 * Internationalization
4612 When supported by the host system, GDB will be built with
4613 internationalization (libintl). The task of marking up the sources is
4614 continued, we're looking forward to our first translation.
4618 Initial support for debugging programs compiled with the GNAT
4619 implementation of the Ada programming language has been integrated
4620 into GDB. In this release, support is limited to expression evaluation.
4622 * New native configurations
4624 GNU/Linux/m32r m32r-*-linux-gnu
4628 GDB's remote protocol now includes support for the 'p' packet. This
4629 packet is used to fetch individual registers from a remote inferior.
4631 * END-OF-LIFE registers[] compatibility module
4633 GDB's internal register infrastructure has been completely rewritten.
4634 The new infrastructure making possible the implementation of key new
4635 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4638 GDB 6.3 will be the last release to include the the registers[]
4639 compatibility module that allowed out-of-date configurations to
4640 continue to work. This change directly impacts the following
4650 powerpc bdm protocol
4652 Unless there is activity to revive these configurations, they will be
4653 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4655 * OBSOLETE configurations and files
4657 Configurations that have been declared obsolete in this release have
4658 been commented out. Unless there is activity to revive these
4659 configurations, the next release of GDB will have their sources
4660 permanently REMOVED.
4669 *** Changes in GDB 6.2.1:
4671 * MIPS `break main; run' gave an heuristic-fence-post warning
4673 When attempting to run even a simple program, a warning about
4674 heuristic-fence-post being hit would be reported. This problem has
4677 * MIPS IRIX 'long double' crashed GDB
4679 When examining a long double variable, GDB would get a segmentation
4680 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4681 IRIX long double values).
4685 A bug in the VAX stack code was causing problems with the "next"
4686 command. This problem has been fixed.
4688 *** Changes in GDB 6.2:
4690 * Fix for ``many threads''
4692 On GNU/Linux systems that use the NPTL threads library, a program
4693 rapidly creating and deleting threads would confuse GDB leading to the
4696 ptrace: No such process.
4697 thread_db_get_info: cannot get thread info: generic error
4699 This problem has been fixed.
4701 * "-async" and "-noasync" options removed.
4703 Support for the broken "-noasync" option has been removed (it caused
4706 * New ``start'' command.
4708 This command runs the program until the begining of the main procedure.
4710 * New BSD Kernel Data Access Library (libkvm) interface
4712 Using ``target kvm'' it is now possible to debug kernel core dumps and
4713 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4714 platforms. Currently supported (native-only) configurations are:
4716 FreeBSD/amd64 x86_64-*-freebsd*
4717 FreeBSD/i386 i?86-*-freebsd*
4718 NetBSD/i386 i?86-*-netbsd*
4719 NetBSD/m68k m68*-*-netbsd*
4720 NetBSD/sparc sparc-*-netbsd*
4721 OpenBSD/amd64 x86_64-*-openbsd*
4722 OpenBSD/i386 i?86-*-openbsd*
4723 OpenBSD/m68k m68*-openbsd*
4724 OpenBSD/sparc sparc-*-openbsd*
4726 * Signal trampoline code overhauled
4728 Many generic problems with GDB's signal handling code have been fixed.
4729 These include: backtraces through non-contiguous stacks; recognition
4730 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4731 call; backtrace through a signal trampoline; step into and out of
4732 signal handlers; and single-stepping in the signal trampoline.
4734 Please note that kernel bugs are a limiting factor here. These
4735 features have been shown to work on an s390 GNU/Linux system that
4736 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4738 * Cygwin support for DWARF 2 added.
4740 * New native configurations
4742 GNU/Linux/hppa hppa*-*-linux*
4743 OpenBSD/hppa hppa*-*-openbsd*
4744 OpenBSD/m68k m68*-*-openbsd*
4745 OpenBSD/m88k m88*-*-openbsd*
4746 OpenBSD/powerpc powerpc-*-openbsd*
4747 NetBSD/vax vax-*-netbsd*
4748 OpenBSD/vax vax-*-openbsd*
4750 * END-OF-LIFE frame compatibility module
4752 GDB's internal frame infrastructure has been completely rewritten.
4753 The new infrastructure making it possible to support key new features
4754 including DWARF 2 Call Frame Information. To aid in the task of
4755 migrating old configurations to this new infrastructure, a
4756 compatibility module, that allowed old configurations to continue to
4757 work, was also included.
4759 GDB 6.2 will be the last release to include this frame compatibility
4760 module. This change directly impacts the following configurations:
4770 Unless there is activity to revive these configurations, they will be
4771 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4773 * REMOVED configurations and files
4775 Sun 3, running SunOS 3 m68*-*-sunos3*
4776 Sun 3, running SunOS 4 m68*-*-sunos4*
4777 Sun 2, running SunOS 3 m68000-*-sunos3*
4778 Sun 2, running SunOS 4 m68000-*-sunos4*
4779 Motorola 680x0 running LynxOS m68*-*-lynxos*
4780 AT&T 3b1/Unix pc m68*-att-*
4781 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4782 decstation mips-dec-* mips-little-*
4783 riscos mips-*-riscos* mips-*-sysv*
4784 sonymips mips-sony-*
4785 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4787 *** Changes in GDB 6.1.1:
4789 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4791 The TUI (Text-mode User Interface) is now built as part of a default
4792 GDB configuration. It is enabled by either selecting the TUI with the
4793 command line option "-i=tui" or by running the separate "gdbtui"
4794 program. For more information on the TUI, see the manual "Debugging
4797 * Pending breakpoint support (also included in GDB 6.1)
4799 Support has been added to allow you to specify breakpoints in shared
4800 libraries that have not yet been loaded. If a breakpoint location
4801 cannot be found, and the "breakpoint pending" option is set to auto,
4802 GDB queries you if you wish to make the breakpoint pending on a future
4803 shared-library load. If and when GDB resolves the breakpoint symbol,
4804 the pending breakpoint is removed as one or more regular breakpoints
4807 Pending breakpoints are very useful for GCJ Java debugging.
4809 * Fixed ISO-C build problems
4811 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4812 non ISO-C code that stopped them being built using a more strict ISO-C
4813 compiler (e.g., IBM's C compiler).
4815 * Fixed build problem on IRIX 5
4817 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4818 wasn't able to compile compile on an IRIX 5 system.
4820 * Added execute permission to gdb/gdbserver/configure
4822 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4823 permission. This bug would cause configure to fail on a number of
4824 systems (Solaris, IRIX). Ref: server/519.
4826 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4828 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4829 has been updated to use constant array sizes.
4831 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4833 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4834 its generated DWARF Call Frame Info. This encoding was causing GDB to
4835 panic, that panic has been fixed. Ref: gdb/1628.
4837 * Fixed a problem when examining parameters in shared library code.
4839 When examining parameters in optimized shared library code generated
4840 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4841 not available''. GDB now correctly displays the variable's value.
4843 *** Changes in GDB 6.1:
4845 * Removed --with-mmalloc
4847 Support for the mmalloc memory manager has been removed, as it
4848 conflicted with the internal gdb byte cache.
4850 * Changes in AMD64 configurations
4852 The AMD64 target now includes the %cs and %ss registers. As a result
4853 the AMD64 remote protocol has changed; this affects the floating-point
4854 and SSE registers. If you rely on those registers for your debugging,
4855 you should upgrade gdbserver on the remote side.
4857 * Revised SPARC target
4859 The SPARC target has been completely revised, incorporating the
4860 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4861 support for LynxOS and SunOS 4 has been dropped. Calling functions
4862 from within GDB on operating systems with a non-executable stack
4863 (Solaris, OpenBSD) now works.
4867 GDB has a new C++ demangler which does a better job on the mangled
4868 names generated by current versions of g++. It also runs faster, so
4869 with this and other changes gdb should now start faster on large C++
4872 * DWARF 2 Location Expressions
4874 GDB support for location expressions has been extended to support function
4875 arguments and frame bases. Older versions of GDB could crash when they
4878 * C++ nested types and namespaces
4880 GDB's support for nested types and namespaces in C++ has been
4881 improved, especially if you use the DWARF 2 debugging format. (This
4882 is the default for recent versions of GCC on most platforms.)
4883 Specifically, if you have a class "Inner" defined within a class or
4884 namespace "Outer", then GDB realizes that the class's name is
4885 "Outer::Inner", not simply "Inner". This should greatly reduce the
4886 frequency of complaints about not finding RTTI symbols. In addition,
4887 if you are stopped at inside of a function defined within a namespace,
4888 GDB modifies its name lookup accordingly.
4890 * New native configurations
4892 NetBSD/amd64 x86_64-*-netbsd*
4893 OpenBSD/amd64 x86_64-*-openbsd*
4894 OpenBSD/alpha alpha*-*-openbsd*
4895 OpenBSD/sparc sparc-*-openbsd*
4896 OpenBSD/sparc64 sparc64-*-openbsd*
4898 * New debugging protocols
4900 M32R with SDI protocol m32r-*-elf*
4902 * "set prompt-escape-char" command deleted.
4904 The command "set prompt-escape-char" has been deleted. This command,
4905 and its very obscure effet on GDB's prompt, was never documented,
4906 tested, nor mentioned in the NEWS file.
4908 * OBSOLETE configurations and files
4910 Configurations that have been declared obsolete in this release have
4911 been commented out. Unless there is activity to revive these
4912 configurations, the next release of GDB will have their sources
4913 permanently REMOVED.
4915 Sun 3, running SunOS 3 m68*-*-sunos3*
4916 Sun 3, running SunOS 4 m68*-*-sunos4*
4917 Sun 2, running SunOS 3 m68000-*-sunos3*
4918 Sun 2, running SunOS 4 m68000-*-sunos4*
4919 Motorola 680x0 running LynxOS m68*-*-lynxos*
4920 AT&T 3b1/Unix pc m68*-att-*
4921 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4922 decstation mips-dec-* mips-little-*
4923 riscos mips-*-riscos* mips-*-sysv*
4924 sonymips mips-sony-*
4925 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4927 * REMOVED configurations and files
4929 SGI Irix-4.x mips-sgi-irix4 or iris4
4930 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4931 Z8000 simulator z8k-zilog-none or z8ksim
4932 Matsushita MN10200 w/simulator mn10200-*-*
4933 H8/500 simulator h8500-hitachi-hms or h8500hms
4934 HP/PA running BSD hppa*-*-bsd*
4935 HP/PA running OSF/1 hppa*-*-osf*
4936 HP/PA Pro target hppa*-*-pro*
4937 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4938 386BSD i[3456]86-*-bsd*
4939 Sequent family i[3456]86-sequent-sysv4*
4940 i[3456]86-sequent-sysv*
4941 i[3456]86-sequent-bsd*
4942 SPARC running LynxOS sparc-*-lynxos*
4943 SPARC running SunOS 4 sparc-*-sunos4*
4944 Tsqware Sparclet sparclet-*-*
4945 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4947 *** Changes in GDB 6.0:
4951 Support for debugging the Objective-C programming language has been
4952 integrated into GDB.
4954 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4956 DWARF 2's Call Frame Information makes available compiler generated
4957 information that more exactly describes the program's run-time stack.
4958 By using this information, GDB is able to provide more robust stack
4961 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4962 have been updated to use a new backtrace mechanism which includes
4963 DWARF 2 CFI support.
4967 GDB's remote protocol has been extended to include support for hosted
4968 file I/O (where the remote target uses GDB's file system). See GDB's
4969 remote protocol documentation for details.
4971 * All targets using the new architecture framework.
4973 All of GDB's targets have been updated to use the new internal
4974 architecture framework. The way is now open for future GDB releases
4975 to include cross-architecture native debugging support (i386 on amd64,
4978 * GNU/Linux's Thread Local Storage (TLS)
4980 GDB now includes support for for the GNU/Linux implementation of
4981 per-thread variables.
4983 * GNU/Linux's Native POSIX Thread Library (NPTL)
4985 GDB's thread code has been updated to work with either the new
4986 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4988 * Separate debug info.
4990 GDB, in conjunction with BINUTILS, now supports a mechanism for
4991 automatically loading debug information from a separate file. Instead
4992 of shipping full debug and non-debug versions of system libraries,
4993 system integrators can now instead ship just the stripped libraries
4994 and optional debug files.
4996 * DWARF 2 Location Expressions
4998 DWARF 2 Location Expressions allow the compiler to more completely
4999 describe the location of variables (even in optimized code) to the
5002 GDB now includes preliminary support for location expressions (support
5003 for DW_OP_piece is still missing).
5007 A number of long standing bugs that caused GDB to die while starting a
5008 Java application have been fixed. GDB's Java support is now
5009 considered "useable".
5011 * GNU/Linux support for fork, vfork, and exec.
5013 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5014 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5017 * GDB supports logging output to a file
5019 There are two new commands, "set logging" and "show logging", which can be
5020 used to capture GDB's output to a file.
5022 * The meaning of "detach" has changed for gdbserver
5024 The "detach" command will now resume the application, as documented. To
5025 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5028 * d10v, m68hc11 `regs' command deprecated
5030 The `info registers' command has been updated so that it displays the
5031 registers using a format identical to the old `regs' command.
5035 A new command, "maint set profile on/off", has been added. This command can
5036 be used to enable or disable profiling while running GDB, to profile a
5037 session or a set of commands. In addition there is a new configure switch,
5038 "--enable-profiling", which will cause GDB to be compiled with profiling
5039 data, for more informative profiling results.
5041 * Default MI syntax changed to "mi2".
5043 The default MI (machine interface) syntax, enabled by the command line
5044 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5045 "mi1", can be enabled by specifying the option "-i=mi1".
5047 Support for the original "mi0" syntax (included in GDB 5.0) has been
5050 Fix for gdb/192: removed extraneous space when displaying frame level.
5051 Fix for gdb/672: update changelist is now output in mi list format.
5052 Fix for gdb/702: a -var-assign that updates the value now shows up
5053 in a subsequent -var-update.
5055 * New native configurations.
5057 FreeBSD/amd64 x86_64-*-freebsd*
5059 * Multi-arched targets.
5061 HP/PA HPUX11 hppa*-*-hpux*
5062 Renesas M32R/D w/simulator m32r-*-elf*
5064 * OBSOLETE configurations and files
5066 Configurations that have been declared obsolete in this release have
5067 been commented out. Unless there is activity to revive these
5068 configurations, the next release of GDB will have their sources
5069 permanently REMOVED.
5071 Z8000 simulator z8k-zilog-none or z8ksim
5072 Matsushita MN10200 w/simulator mn10200-*-*
5073 H8/500 simulator h8500-hitachi-hms or h8500hms
5074 HP/PA running BSD hppa*-*-bsd*
5075 HP/PA running OSF/1 hppa*-*-osf*
5076 HP/PA Pro target hppa*-*-pro*
5077 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5078 Sequent family i[3456]86-sequent-sysv4*
5079 i[3456]86-sequent-sysv*
5080 i[3456]86-sequent-bsd*
5081 Tsqware Sparclet sparclet-*-*
5082 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5084 * REMOVED configurations and files
5087 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5088 IBM AIX PS/2 i[3456]86-*-aix
5089 i386 running Mach 3.0 i[3456]86-*-mach3*
5090 i386 running Mach i[3456]86-*-mach*
5091 i386 running OSF/1 i[3456]86-*osf1mk*
5092 HP/Apollo 68k Family m68*-apollo*-sysv*,
5094 m68*-hp-bsd*, m68*-hp-hpux*
5095 Argonaut Risc Chip (ARC) arc-*-*
5096 Mitsubishi D30V d30v-*-*
5097 Fujitsu FR30 fr30-*-elf*
5098 OS/9000 i[34]86-*-os9k
5099 I960 with MON960 i960-*-coff
5101 * MIPS $fp behavior changed
5103 The convenience variable $fp, for the MIPS, now consistently returns
5104 the address of the current frame's base. Previously, depending on the
5105 context, $fp could refer to either $sp or the current frame's base
5106 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5107 The GNU Source-Level Debugger''.
5109 *** Changes in GDB 5.3:
5111 * GNU/Linux shared library multi-threaded performance improved.
5113 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5114 `/proc', in preference to `ptrace' for memory reads. This may result
5115 in an improvement in the start-up time of multi-threaded, shared
5116 library applications when run under GDB. One GDB user writes: ``loads
5117 shared libs like mad''.
5119 * ``gdbserver'' now supports multi-threaded applications on some targets
5121 Support for debugging multi-threaded applications which use
5122 the GNU/Linux LinuxThreads package has been added for
5123 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5124 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5126 * GDB now supports C/C++ preprocessor macros.
5128 GDB now expands preprocessor macro invocations in C/C++ expressions,
5129 and provides various commands for showing macro definitions and how
5132 The new command `macro expand EXPRESSION' expands any macro
5133 invocations in expression, and shows the result.
5135 The new command `show macro MACRO-NAME' shows the definition of the
5136 macro named MACRO-NAME, and where it was defined.
5138 Most compilers don't include information about macros in the debugging
5139 information by default. In GCC 3.1, for example, you need to compile
5140 your program with the options `-gdwarf-2 -g3'. If the macro
5141 information is present in the executable, GDB will read it.
5143 * Multi-arched targets.
5145 DEC Alpha (partial) alpha*-*-*
5146 DEC VAX (partial) vax-*-*
5148 National Semiconductor NS32000 (partial) ns32k-*-*
5149 Motorola 68000 (partial) m68k-*-*
5150 Motorola MCORE mcore-*-*
5154 Fujitsu FRV architecture added by Red Hat frv*-*-*
5157 * New native configurations
5159 Alpha NetBSD alpha*-*-netbsd*
5160 SH NetBSD sh*-*-netbsdelf*
5161 MIPS NetBSD mips*-*-netbsd*
5162 UltraSPARC NetBSD sparc64-*-netbsd*
5164 * OBSOLETE configurations and files
5166 Configurations that have been declared obsolete in this release have
5167 been commented out. Unless there is activity to revive these
5168 configurations, the next release of GDB will have their sources
5169 permanently REMOVED.
5171 Mitsubishi D30V d30v-*-*
5172 OS/9000 i[34]86-*-os9k
5173 IBM AIX PS/2 i[3456]86-*-aix
5174 Fujitsu FR30 fr30-*-elf*
5175 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5176 Argonaut Risc Chip (ARC) arc-*-*
5177 i386 running Mach 3.0 i[3456]86-*-mach3*
5178 i386 running Mach i[3456]86-*-mach*
5179 i386 running OSF/1 i[3456]86-*osf1mk*
5180 HP/Apollo 68k Family m68*-apollo*-sysv*,
5182 m68*-hp-bsd*, m68*-hp-hpux*
5183 I960 with MON960 i960-*-coff
5185 * OBSOLETE languages
5187 CHILL, a Pascal like language used by telecommunications companies.
5189 * REMOVED configurations and files
5191 AMD 29k family via UDI a29k-amd-udi, udi29k
5192 A29K VxWorks a29k-*-vxworks
5193 AMD 29000 embedded, using EBMON a29k-none-none
5194 AMD 29000 embedded with COFF a29k-none-coff
5195 AMD 29000 embedded with a.out a29k-none-aout
5197 testsuite/gdb.hp/gdb.threads-hp/ directory
5199 * New command "set max-user-call-depth <nnn>"
5201 This command allows the user to limit the call depth of user-defined
5202 commands. The default is 1024.
5204 * Changes in FreeBSD/i386 native debugging.
5206 Support for the "generate-core-file" has been added.
5208 * New commands "dump", "append", and "restore".
5210 These commands allow data to be copied from target memory
5211 to a bfd-format or binary file (dump and append), and back
5212 from a file into memory (restore).
5214 * Improved "next/step" support on multi-processor Alpha Tru64.
5216 The previous single-step mechanism could cause unpredictable problems,
5217 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5218 of a software single-step mechanism prevents this.
5220 *** Changes in GDB 5.2.1:
5228 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5229 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5230 Fix, by Joel Brobecker imported from mainline.
5232 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5233 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5234 Fix, by Fred Fish, imported from mainline.
5236 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5237 Surprisingly enough, it works now.
5238 By Michal Ludvig, imported from mainline.
5240 i386 hardware watchpoint support:
5241 avoid misses on second run for some targets.
5242 By Pierre Muller, imported from mainline.
5244 *** Changes in GDB 5.2:
5246 * New command "set trust-readonly-sections on[off]".
5248 This command is a hint that tells gdb that read-only sections
5249 really are read-only (ie. that their contents will not change).
5250 In this mode, gdb will go to the object file rather than the
5251 target to read memory from read-only sections (such as ".text").
5252 This can be a significant performance improvement on some
5253 (notably embedded) targets.
5255 * New command "generate-core-file" (or "gcore").
5257 This new gdb command allows the user to drop a core file of the child
5258 process state at any time. So far it's been implemented only for
5259 GNU/Linux and Solaris, but should be relatively easily ported to other
5260 hosts. Argument is core file name (defaults to core.<pid>).
5262 * New command line option
5264 GDB now accepts --pid or -p followed by a process id.
5266 * Change in command line behavior -- corefiles vs. process ids.
5268 There is a subtle behavior in the way in which GDB handles
5269 command line arguments. The first non-flag argument is always
5270 a program to debug, but the second non-flag argument may either
5271 be a corefile or a process id. Previously, GDB would attempt to
5272 open the second argument as a corefile, and if that failed, would
5273 issue a superfluous error message and then attempt to attach it as
5274 a process. Now, if the second argument begins with a non-digit,
5275 it will be treated as a corefile. If it begins with a digit,
5276 GDB will attempt to attach it as a process, and if no such process
5277 is found, will then attempt to open it as a corefile.
5279 * Changes in ARM configurations.
5281 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5282 configuration is fully multi-arch.
5284 * New native configurations
5286 ARM NetBSD arm*-*-netbsd*
5287 x86 OpenBSD i[3456]86-*-openbsd*
5288 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5289 Sparc64 running FreeBSD sparc64-*-freebsd*
5293 Sanyo XStormy16 xstormy16-elf
5295 * OBSOLETE configurations and files
5297 Configurations that have been declared obsolete in this release have
5298 been commented out. Unless there is activity to revive these
5299 configurations, the next release of GDB will have their sources
5300 permanently REMOVED.
5302 AMD 29k family via UDI a29k-amd-udi, udi29k
5303 A29K VxWorks a29k-*-vxworks
5304 AMD 29000 embedded, using EBMON a29k-none-none
5305 AMD 29000 embedded with COFF a29k-none-coff
5306 AMD 29000 embedded with a.out a29k-none-aout
5308 testsuite/gdb.hp/gdb.threads-hp/ directory
5310 * REMOVED configurations and files
5312 TI TMS320C80 tic80-*-*
5314 PowerPC Solaris powerpcle-*-solaris*
5315 PowerPC Windows NT powerpcle-*-cygwin32
5316 PowerPC Netware powerpc-*-netware*
5317 Harris/CXUX m88k m88*-harris-cxux*
5318 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5319 ns32k-utek-sysv* ns32k-utek-*
5320 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5321 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5322 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5323 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5324 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5326 * Changes to command line processing
5328 The new `--args' feature can be used to specify command-line arguments
5329 for the inferior from gdb's command line.
5331 * Changes to key bindings
5333 There is a new `operate-and-get-next' function bound to `C-o'.
5335 *** Changes in GDB 5.1.1
5337 Fix compile problem on DJGPP.
5339 Fix a problem with floating-point registers on the i386 being
5342 Fix to stop GDB crashing on .debug_str debug info.
5344 Numerous documentation fixes.
5346 Numerous testsuite fixes.
5348 *** Changes in GDB 5.1:
5350 * New native configurations
5352 Alpha FreeBSD alpha*-*-freebsd*
5353 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5354 MIPS GNU/Linux mips*-*-linux*
5355 MIPS SGI Irix 6.x mips*-sgi-irix6*
5356 ia64 AIX ia64-*-aix*
5357 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5361 Motorola 68HC11 and 68HC12 m68hc11-elf
5363 UltraSparc running GNU/Linux sparc64-*-linux*
5365 * OBSOLETE configurations and files
5367 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5368 Harris/CXUX m88k m88*-harris-cxux*
5369 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5370 ns32k-utek-sysv* ns32k-utek-*
5371 TI TMS320C80 tic80-*-*
5373 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5374 PowerPC Solaris powerpcle-*-solaris*
5375 PowerPC Windows NT powerpcle-*-cygwin32
5376 PowerPC Netware powerpc-*-netware*
5377 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5378 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5379 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5380 Apple Macintosh (MPW) host N/A
5382 stuff.c (Program to stuff files into a specially prepared space in kdb)
5383 kdb-start.c (Main loop for the standalone kernel debugger)
5385 Configurations that have been declared obsolete in this release have
5386 been commented out. Unless there is activity to revive these
5387 configurations, the next release of GDB will have their sources
5388 permanently REMOVED.
5390 * REMOVED configurations and files
5392 Altos 3068 m68*-altos-*
5393 Convex c1-*-*, c2-*-*
5395 ARM RISCix arm-*-* (as host)
5399 * GDB has been converted to ISO C.
5401 GDB's source code has been converted to ISO C. In particular, the
5402 sources are fully protoized, and rely on standard headers being
5407 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5409 * The MI enabled by default.
5411 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5412 revised and enabled by default. Packages which use GDB as a debugging
5413 engine behind a UI or another front end are encouraged to switch to
5414 using the GDB/MI interface, instead of the old annotations interface
5415 which is now deprecated.
5417 * Support for debugging Pascal programs.
5419 GDB now includes support for debugging Pascal programs. The following
5420 main features are supported:
5422 - Pascal-specific data types such as sets;
5424 - automatic recognition of Pascal sources based on file-name
5427 - Pascal-style display of data types, variables, and functions;
5429 - a Pascal expression parser.
5431 However, some important features are not yet supported.
5433 - Pascal string operations are not supported at all;
5435 - there are some problems with boolean types;
5437 - Pascal type hexadecimal constants are not supported
5438 because they conflict with the internal variables format;
5440 - support for Pascal objects and classes is not full yet;
5442 - unlike Pascal, GDB is case-sensitive for symbol names.
5444 * Changes in completion.
5446 Commands such as `shell', `run' and `set args', which pass arguments
5447 to inferior programs, now complete on file names, similar to what
5448 users expect at the shell prompt.
5450 Commands which accept locations, such as `disassemble', `print',
5451 `breakpoint', `until', etc. now complete on filenames as well as
5452 program symbols. Thus, if you type "break foob TAB", and the source
5453 files linked into the programs include `foobar.c', that file name will
5454 be one of the candidates for completion. However, file names are not
5455 considered for completion after you typed a colon that delimits a file
5456 name from a name of a function in that file, as in "break foo.c:bar".
5458 `set demangle-style' completes on available demangling styles.
5460 * New platform-independent commands:
5462 It is now possible to define a post-hook for a command as well as a
5463 hook that runs before the command. For more details, see the
5464 documentation of `hookpost' in the GDB manual.
5466 * Changes in GNU/Linux native debugging.
5468 Support for debugging multi-threaded programs has been completely
5469 revised for all platforms except m68k and sparc. You can now debug as
5470 many threads as your system allows you to have.
5472 Attach/detach is supported for multi-threaded programs.
5474 Support for SSE registers was added for x86. This doesn't work for
5475 multi-threaded programs though.
5477 * Changes in MIPS configurations.
5479 Multi-arch support is enabled for all MIPS configurations.
5481 GDB can now be built as native debugger on SGI Irix 6.x systems for
5482 debugging n32 executables. (Debugging 64-bit executables is not yet
5485 * Unified support for hardware watchpoints in all x86 configurations.
5487 Most (if not all) native x86 configurations support hardware-assisted
5488 breakpoints and watchpoints in a unified manner. This support
5489 implements debug register sharing between watchpoints, which allows to
5490 put a virtually infinite number of watchpoints on the same address,
5491 and also supports watching regions up to 16 bytes with several debug
5494 The new maintenance command `maintenance show-debug-regs' toggles
5495 debugging print-outs in functions that insert, remove, and test
5496 watchpoints and hardware breakpoints.
5498 * Changes in the DJGPP native configuration.
5500 New command ``info dos sysinfo'' displays assorted information about
5501 the CPU, OS, memory, and DPMI server.
5503 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5504 display information about segment descriptors stored in GDT, LDT, and
5507 New commands ``info dos pde'' and ``info dos pte'' display entries
5508 from Page Directory and Page Tables (for now works with CWSDPMI only).
5509 New command ``info dos address-pte'' displays the Page Table entry for
5510 a given linear address.
5512 GDB can now pass command lines longer than 126 characters to the
5513 program being debugged (requires an update to the libdbg.a library
5514 which is part of the DJGPP development kit).
5516 DWARF2 debug info is now supported.
5518 It is now possible to `step' and `next' through calls to `longjmp'.
5520 * Changes in documentation.
5522 All GDB documentation was converted to GFDL, the GNU Free
5523 Documentation License.
5525 Tracepoints-related commands are now fully documented in the GDB
5528 TUI, the Text-mode User Interface, is now documented in the manual.
5530 Tracepoints-related commands are now fully documented in the GDB
5533 The "GDB Internals" manual now has an index. It also includes
5534 documentation of `ui_out' functions, GDB coding standards, x86
5535 hardware watchpoints, and memory region attributes.
5537 * GDB's version number moved to ``version.in''
5539 The Makefile variable VERSION has been replaced by the file
5540 ``version.in''. People creating GDB distributions should update the
5541 contents of this file.
5545 GUD support is now a standard part of the EMACS distribution.
5547 *** Changes in GDB 5.0:
5549 * Improved support for debugging FP programs on x86 targets
5551 Unified and much-improved support for debugging floating-point
5552 programs on all x86 targets. In particular, ``info float'' now
5553 displays the FP registers in the same format on all x86 targets, with
5554 greater level of detail.
5556 * Improvements and bugfixes in hardware-assisted watchpoints
5558 It is now possible to watch array elements, struct members, and
5559 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5560 on x86 targets no longer erroneously trigger when the address is
5563 * Improvements in the native DJGPP version of GDB
5565 The distribution now includes all the scripts and auxiliary files
5566 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5567 machines ``out of the box''.
5569 The DJGPP version can now debug programs that use signals. It is
5570 possible to catch signals that happened in the debuggee, deliver
5571 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5572 would kill the program being debugged.) Programs that hook hardware
5573 interrupts (keyboard, timer, etc.) can also be debugged.
5575 It is now possible to debug DJGPP programs that redirect their
5576 standard handles or switch them to raw (as opposed to cooked) mode, or
5577 even close them. The command ``run < foo > bar'' works as expected,
5578 and ``info terminal'' reports useful information about the debuggee's
5579 terminal, including raw/cooked mode, redirection, etc.
5581 The DJGPP version now uses termios functions for console I/O, which
5582 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5585 DOS-style file names with drive letters are now fully supported by
5588 It is now possible to debug DJGPP programs that switch their working
5589 directory. It is also possible to rerun the debuggee any number of
5590 times without restarting GDB; thus, you can use the same setup,
5591 breakpoints, etc. for many debugging sessions.
5593 * New native configurations
5595 ARM GNU/Linux arm*-*-linux*
5596 PowerPC GNU/Linux powerpc-*-linux*
5600 Motorola MCore mcore-*-*
5601 x86 VxWorks i[3456]86-*-vxworks*
5602 PowerPC VxWorks powerpc-*-vxworks*
5603 TI TMS320C80 tic80-*-*
5605 * OBSOLETE configurations
5607 Altos 3068 m68*-altos-*
5608 Convex c1-*-*, c2-*-*
5610 ARM RISCix arm-*-* (as host)
5613 Configurations that have been declared obsolete will be commented out,
5614 but the code will be left in place. If there is no activity to revive
5615 these configurations before the next release of GDB, the sources will
5616 be permanently REMOVED.
5618 * Gould support removed
5620 Support for the Gould PowerNode and NP1 has been removed.
5622 * New features for SVR4
5624 On SVR4 native platforms (such as Solaris), if you attach to a process
5625 without first loading a symbol file, GDB will now attempt to locate and
5626 load symbols from the running process's executable file.
5628 * Many C++ enhancements
5630 C++ support has been greatly improved. Overload resolution now works properly
5631 in almost all cases. RTTI support is on the way.
5633 * Remote targets can connect to a sub-program
5635 A popen(3) style serial-device has been added. This device starts a
5636 sub-process (such as a stand-alone simulator) and then communicates
5637 with that. The sub-program to run is specified using the syntax
5638 ``|<program> <args>'' vis:
5640 (gdb) set remotedebug 1
5641 (gdb) target extended-remote |mn10300-elf-sim program-args
5643 * MIPS 64 remote protocol
5645 A long standing bug in the mips64 remote protocol where by GDB
5646 expected certain 32 bit registers (ex SR) to be transfered as 32
5647 instead of 64 bits has been fixed.
5649 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5650 added to provide backward compatibility with older versions of GDB.
5652 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5654 The command ``set remotebinarydownload'' command has been replaced by
5655 ``set remote X-packet''. Other commands in ``set remote'' family
5656 include ``set remote P-packet''.
5658 * Breakpoint commands accept ranges.
5660 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5661 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5662 ``tracepoint passcount'' also accepts a range of tracepoints.
5664 * ``apropos'' command added.
5666 The ``apropos'' command searches through command names and
5667 documentation strings, printing out matches, making it much easier to
5668 try to find a command that does what you are looking for.
5672 A new machine oriented interface (MI) has been added to GDB. This
5673 interface is designed for debug environments running GDB as a separate
5674 process. This is part of the long term libGDB project. See the
5675 "GDB/MI" chapter of the GDB manual for further information. It can be
5676 enabled by configuring with:
5678 .../configure --enable-gdbmi
5680 *** Changes in GDB-4.18:
5682 * New native configurations
5684 HP-UX 10.20 hppa*-*-hpux10.20
5685 HP-UX 11.x hppa*-*-hpux11.0*
5686 M68K GNU/Linux m68*-*-linux*
5690 Fujitsu FR30 fr30-*-elf*
5691 Intel StrongARM strongarm-*-*
5692 Mitsubishi D30V d30v-*-*
5694 * OBSOLETE configurations
5696 Gould PowerNode, NP1 np1-*-*, pn-*-*
5698 Configurations that have been declared obsolete will be commented out,
5699 but the code will be left in place. If there is no activity to revive
5700 these configurations before the next release of GDB, the sources will
5701 be permanently REMOVED.
5705 As a compatibility experiment, GDB's source files buildsym.h and
5706 buildsym.c have been converted to pure standard C, no longer
5707 containing any K&R compatibility code. We believe that all systems in
5708 use today either come with a standard C compiler, or have a GCC port
5709 available. If this is not true, please report the affected
5710 configuration to bug-gdb@gnu.org immediately. See the README file for
5711 information about getting a standard C compiler if you don't have one
5716 GDB now uses readline 2.2.
5718 * set extension-language
5720 You can now control the mapping between filename extensions and source
5721 languages by using the `set extension-language' command. For instance,
5722 you can ask GDB to treat .c files as C++ by saying
5723 set extension-language .c c++
5724 The command `info extensions' lists all of the recognized extensions
5725 and their associated languages.
5727 * Setting processor type for PowerPC and RS/6000
5729 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5730 you can use the `set processor' command to specify what variant of the
5731 PowerPC family you are debugging. The command
5735 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5736 following PowerPC and RS6000 variants:
5738 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5739 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5741 403GC IBM PowerPC 403GC
5742 505 Motorola PowerPC 505
5743 860 Motorola PowerPC 860 or 850
5744 601 Motorola PowerPC 601
5745 602 Motorola PowerPC 602
5746 603 Motorola/IBM PowerPC 603 or 603e
5747 604 Motorola PowerPC 604 or 604e
5748 750 Motorola/IBM PowerPC 750 or 750
5750 At the moment, this command just tells GDB what to name the
5751 special-purpose processor registers. Since almost all the affected
5752 registers are inaccessible to user-level programs, this command is
5753 only useful for remote debugging in its present form.
5757 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5758 more extensive support for HP-UX. Added features include shared
5759 library support, kernel threads and hardware watchpoints for 11.00,
5760 support for HP's ANSI C and C++ compilers, and a compatibility mode
5761 for xdb and dbx commands.
5765 HP's donation includes the new concept of catchpoints, which is a
5766 generalization of the old catch command. On HP-UX, it is now possible
5767 to catch exec, fork, and vfork, as well as library loading.
5769 This means that the existing catch command has changed; its first
5770 argument now specifies the type of catch to be set up. See the
5771 output of "help catch" for a list of catchpoint types.
5773 * Debugging across forks
5775 On HP-UX, you can choose which process to debug when a fork() happens
5780 HP has donated a curses-based terminal user interface (TUI). To get
5781 it, build with --enable-tui. Although this can be enabled for any
5782 configuration, at present it only works for native HP debugging.
5784 * GDB remote protocol additions
5786 A new protocol packet 'X' that writes binary data is now available.
5787 Default behavior is to try 'X', then drop back to 'M' if the stub
5788 fails to respond. The settable variable `remotebinarydownload'
5789 allows explicit control over the use of 'X'.
5791 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5792 full 64-bit address. The command
5794 set remoteaddresssize 32
5796 can be used to revert to the old behaviour. For existing remote stubs
5797 the change should not be noticed, as the additional address information
5800 In order to assist in debugging stubs, you may use the maintenance
5801 command `packet' to send any text string to the stub. For instance,
5803 maint packet heythere
5805 sends the packet "$heythere#<checksum>". Note that it is very easy to
5806 disrupt a debugging session by sending the wrong packet at the wrong
5809 The compare-sections command allows you to compare section data on the
5810 target to what is in the executable file without uploading or
5811 downloading, by comparing CRC checksums.
5813 * Tracing can collect general expressions
5815 You may now collect general expressions at tracepoints. This requires
5816 further additions to the target-side stub; see tracepoint.c and
5817 doc/agentexpr.texi for further details.
5819 * mask-address variable for Mips
5821 For Mips targets, you may control the zeroing of the upper 32 bits of
5822 a 64-bit address by entering `set mask-address on'. This is mainly
5823 of interest to users of embedded R4xxx and R5xxx processors.
5825 * Higher serial baud rates
5827 GDB's serial code now allows you to specify baud rates 57600, 115200,
5828 230400, and 460800 baud. (Note that your host system may not be able
5829 to achieve all of these rates.)
5833 The i960 configuration now includes an initial implementation of a
5834 builtin simulator, contributed by Jim Wilson.
5837 *** Changes in GDB-4.17:
5839 * New native configurations
5841 Alpha GNU/Linux alpha*-*-linux*
5842 Unixware 2.x i[3456]86-unixware2*
5843 Irix 6.x mips*-sgi-irix6*
5844 PowerPC GNU/Linux powerpc-*-linux*
5845 PowerPC Solaris powerpcle-*-solaris*
5846 Sparc GNU/Linux sparc-*-linux*
5847 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5851 Argonaut Risc Chip (ARC) arc-*-*
5852 Hitachi H8/300S h8300*-*-*
5853 Matsushita MN10200 w/simulator mn10200-*-*
5854 Matsushita MN10300 w/simulator mn10300-*-*
5855 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5856 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5857 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5858 Mitsubishi D10V w/simulator d10v-*-*
5859 Mitsubishi M32R/D w/simulator m32r-*-elf*
5860 Tsqware Sparclet sparclet-*-*
5861 NEC V850 w/simulator v850-*-*
5863 * New debugging protocols
5865 ARM with RDI protocol arm*-*-*
5866 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5867 DDB and LSI variants of PMON protocol mips*-*-*
5868 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5869 PowerPC with SDS protocol powerpc{,le}-*-eabi
5870 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5874 All configurations can now understand and use the DWARF 2 debugging
5875 format. The choice is automatic, if the symbol file contains DWARF 2
5880 GDB now includes basic Java language support. This support is
5881 only useful with Java compilers that produce native machine code.
5883 * solib-absolute-prefix and solib-search-path
5885 For SunOS and SVR4 shared libraries, you may now set the prefix for
5886 loading absolute shared library symbol files, and the search path for
5887 locating non-absolute shared library symbol files.
5889 * Live range splitting
5891 GDB can now effectively debug code for which GCC has performed live
5892 range splitting as part of its optimization. See gdb/doc/LRS for
5893 more details on the expected format of the stabs information.
5897 GDB's support for the GNU Hurd, including thread debugging, has been
5898 updated to work with current versions of the Hurd.
5902 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5903 instruction set. ARM GDB automatically detects when Thumb
5904 instructions are in use, and adjusts disassembly and backtracing
5909 GDB's MIPS target configurations now handle the MIP16 16-bit
5914 GDB now includes support for overlays; if an executable has been
5915 linked such that multiple sections are based at the same address, GDB
5916 will decide which section to use for symbolic info. You can choose to
5917 control the decision manually, using overlay commands, or implement
5918 additional target-side support and use "overlay load-target" to bring
5919 in the overlay mapping. Do "help overlay" for more detail.
5923 The command "info symbol <address>" displays information about
5924 the symbol at the specified address.
5928 The standard remote protocol now includes an extension that allows
5929 asynchronous collection and display of trace data. This requires
5930 extensive support in the target-side debugging stub. Tracing mode
5931 includes a new interaction mode in GDB and new commands: see the
5932 file tracepoint.c for more details.
5936 Configurations for embedded MIPS now include a simulator contributed
5937 by Cygnus Solutions. The simulator supports the instruction sets
5938 of most MIPS variants.
5942 Sparc configurations may now include the ERC32 simulator contributed
5943 by the European Space Agency. The simulator is not built into
5944 Sparc targets by default; configure with --enable-sim to include it.
5948 For target configurations that may include multiple variants of a
5949 basic architecture (such as MIPS and SH), you may now set the
5950 architecture explicitly. "set arch" sets, "info arch" lists
5951 the possible architectures.
5953 *** Changes in GDB-4.16:
5955 * New native configurations
5957 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5958 M68K NetBSD m68k-*-netbsd*
5959 PowerPC AIX 4.x powerpc-*-aix*
5960 PowerPC MacOS powerpc-*-macos*
5961 PowerPC Windows NT powerpcle-*-cygwin32
5962 RS/6000 AIX 4.x rs6000-*-aix4*
5966 ARM with RDP protocol arm-*-*
5967 I960 with MON960 i960-*-coff
5968 MIPS VxWorks mips*-*-vxworks*
5969 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5970 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5972 Matra Sparclet sparclet-*-*
5976 The powerpc-eabi configuration now includes the PSIM simulator,
5977 contributed by Andrew Cagney, with assistance from Mike Meissner.
5978 PSIM is a very elaborate model of the PowerPC, including not only
5979 basic instruction set execution, but also details of execution unit
5980 performance and I/O hardware. See sim/ppc/README for more details.
5984 GDB now works with Solaris 2.5.
5986 * Windows 95/NT native
5988 GDB will now work as a native debugger on Windows 95 and Windows NT.
5989 To build it from source, you must use the "gnu-win32" environment,
5990 which uses a DLL to emulate enough of Unix to run the GNU tools.
5991 Further information, binaries, and sources are available at
5992 ftp.cygnus.com, under pub/gnu-win32.
5994 * dont-repeat command
5996 If a user-defined command includes the command `dont-repeat', then the
5997 command will not be repeated if the user just types return. This is
5998 useful if the command is time-consuming to run, so that accidental
5999 extra keystrokes don't run the same command many times.
6001 * Send break instead of ^C
6003 The standard remote protocol now includes an option to send a break
6004 rather than a ^C to the target in order to interrupt it. By default,
6005 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6007 * Remote protocol timeout
6009 The standard remote protocol includes a new variable `remotetimeout'
6010 that allows you to set the number of seconds before GDB gives up trying
6011 to read from the target. The default value is 2.
6013 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6015 By default GDB will automatically keep track of objects as they are
6016 loaded and unloaded by the dynamic linker. By using the command `set
6017 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6018 when shared library events occur, thus allowing you to set breakpoints
6019 in shared libraries which are explicitly loaded by the inferior.
6021 Note this feature does not work on hpux8. On hpux9 you must link
6022 /usr/lib/end.o into your program. This feature should work
6023 automatically on hpux10.
6025 * Irix 5.x hardware watchpoint support
6027 Irix 5 configurations now support the use of hardware watchpoints.
6029 * Mips protocol "SYN garbage limit"
6031 When debugging a Mips target using the `target mips' protocol, you
6032 may set the number of characters that GDB will ignore by setting
6033 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6034 every character. The default value is 1050.
6036 * Recording and replaying remote debug sessions
6038 If you set `remotelogfile' to the name of a file, gdb will write to it
6039 a recording of a remote debug session. This recording may then be
6040 replayed back to gdb using "gdbreplay". See gdbserver/README for
6041 details. This is useful when you have a problem with GDB while doing
6042 remote debugging; you can make a recording of the session and send it
6043 to someone else, who can then recreate the problem.
6045 * Speedups for remote debugging
6047 GDB includes speedups for downloading and stepping MIPS systems using
6048 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6049 and more efficient S-record downloading.
6051 * Memory use reductions and statistics collection
6053 GDB now uses less memory and reports statistics about memory usage.
6054 Try the `maint print statistics' command, for example.
6056 *** Changes in GDB-4.15:
6058 * Psymtabs for XCOFF
6060 The symbol reader for AIX GDB now uses partial symbol tables. This
6061 can greatly improve startup time, especially for large executables.
6063 * Remote targets use caching
6065 Remote targets now use a data cache to speed up communication with the
6066 remote side. The data cache could lead to incorrect results because
6067 it doesn't know about volatile variables, thus making it impossible to
6068 debug targets which use memory mapped I/O devices. `set remotecache
6069 off' turns the the data cache off.
6071 * Remote targets may have threads
6073 The standard remote protocol now includes support for multiple threads
6074 in the target system, using new protocol commands 'H' and 'T'. See
6075 gdb/remote.c for details.
6079 If GDB is configured with `--enable-netrom', then it will include
6080 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6081 acts as though it is a bank of ROM on the target board, but you can
6082 write into it over the network. GDB's support consists only of
6083 support for fast loading into the emulated ROM; to debug, you must use
6084 another protocol, such as standard remote protocol. The usual
6085 sequence is something like
6087 target nrom <netrom-hostname>
6089 target remote <netrom-hostname>:1235
6093 GDB now includes support for the Apple Macintosh, as a host only. It
6094 may be run as either an MPW tool or as a standalone application, and
6095 it can debug through the serial port. All the usual GDB commands are
6096 available, but to the target command, you must supply "serial" as the
6097 device type instead of "/dev/ttyXX". See mpw-README in the main
6098 directory for more information on how to build. The MPW configuration
6099 scripts */mpw-config.in support only a few targets, and only the
6100 mips-idt-ecoff target has been tested.
6104 GDB configuration now uses autoconf. This is not user-visible,
6105 but does simplify configuration and building.
6109 GDB now supports hpux10.
6111 *** Changes in GDB-4.14:
6113 * New native configurations
6115 x86 FreeBSD i[345]86-*-freebsd
6116 x86 NetBSD i[345]86-*-netbsd
6117 NS32k NetBSD ns32k-*-netbsd
6118 Sparc NetBSD sparc-*-netbsd
6122 A29K VxWorks a29k-*-vxworks
6123 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6124 CPU32 EST-300 emulator m68*-*-est*
6125 PowerPC ELF powerpc-*-elf
6128 * Alpha OSF/1 support for procfs
6130 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6131 possible to attach to running processes. As the mounting of the /proc
6132 filesystem is optional on the Alpha, GDB automatically determines
6133 the availability of /proc during startup. This can lead to problems
6134 if /proc is unmounted after GDB has been started.
6136 * Arguments to user-defined commands
6138 User commands may accept up to 10 arguments separated by whitespace.
6139 Arguments are accessed within the user command via $arg0..$arg9. A
6142 print $arg0 + $arg1 + $arg2
6144 To execute the command use:
6147 Defines the command "adder" which prints the sum of its three arguments.
6148 Note the arguments are text substitutions, so they may reference variables,
6149 use complex expressions, or even perform inferior function calls.
6151 * New `if' and `while' commands
6153 This makes it possible to write more sophisticated user-defined
6154 commands. Both commands take a single argument, which is the
6155 expression to evaluate, and must be followed by the commands to
6156 execute, one per line, if the expression is nonzero, the list being
6157 terminated by the word `end'. The `if' command list may include an
6158 `else' word, which causes the following commands to be executed only
6159 if the expression is zero.
6161 * Fortran source language mode
6163 GDB now includes partial support for Fortran 77. It will recognize
6164 Fortran programs and can evaluate a subset of Fortran expressions, but
6165 variables and functions may not be handled correctly. GDB will work
6166 with G77, but does not yet know much about symbols emitted by other
6169 * Better HPUX support
6171 Most debugging facilities now work on dynamic executables for HPPAs
6172 running hpux9 or later. You can attach to running dynamically linked
6173 processes, but by default the dynamic libraries will be read-only, so
6174 for instance you won't be able to put breakpoints in them. To change
6175 that behavior do the following before running the program:
6181 This will cause the libraries to be mapped private and read-write.
6182 To revert to the normal behavior, do this:
6188 You cannot set breakpoints or examine data in the library until after
6189 the library is loaded if the function/data symbols do not have
6192 GDB can now also read debug symbols produced by the HP C compiler on
6193 HPPAs (sorry, no C++, Fortran or 68k support).
6195 * Target byte order now dynamically selectable
6197 You can choose which byte order to use with a target system, via the
6198 commands "set endian big" and "set endian little", and you can see the
6199 current setting by using "show endian". You can also give the command
6200 "set endian auto", in which case GDB will use the byte order
6201 associated with the executable. Currently, only embedded MIPS
6202 configurations support dynamic selection of target byte order.
6204 * New DOS host serial code
6206 This version uses DPMI interrupts to handle buffered I/O, so you
6207 no longer need to run asynctsr when debugging boards connected to
6210 *** Changes in GDB-4.13:
6212 * New "complete" command
6214 This lists all the possible completions for the rest of the line, if it
6215 were to be given as a command itself. This is intended for use by emacs.
6217 * Trailing space optional in prompt
6219 "set prompt" no longer adds a space for you after the prompt you set. This
6220 allows you to set a prompt which ends in a space or one that does not.
6222 * Breakpoint hit counts
6224 "info break" now displays a count of the number of times the breakpoint
6225 has been hit. This is especially useful in conjunction with "ignore"; you
6226 can ignore a large number of breakpoint hits, look at the breakpoint info
6227 to see how many times the breakpoint was hit, then run again, ignoring one
6228 less than that number, and this will get you quickly to the last hit of
6231 * Ability to stop printing at NULL character
6233 "set print null-stop" will cause GDB to stop printing the characters of
6234 an array when the first NULL is encountered. This is useful when large
6235 arrays actually contain only short strings.
6237 * Shared library breakpoints
6239 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6240 breakpoints in shared libraries before the executable is run.
6242 * Hardware watchpoints
6244 There is a new hardware breakpoint for the watch command for sparclite
6245 targets. See gdb/sparclite/hw_breakpoint.note.
6247 Hardware watchpoints are also now supported under GNU/Linux.
6251 Annotations have been added. These are for use with graphical interfaces,
6252 and are still experimental. Currently only gdba.el uses these.
6254 * Improved Irix 5 support
6256 GDB now works properly with Irix 5.2.
6258 * Improved HPPA support
6260 GDB now works properly with the latest GCC and GAS.
6262 * New native configurations
6264 Sequent PTX4 i[34]86-sequent-ptx4
6265 HPPA running OSF/1 hppa*-*-osf*
6266 Atari TT running SVR4 m68*-*-sysv4*
6267 RS/6000 LynxOS rs6000-*-lynxos*
6271 OS/9000 i[34]86-*-os9k
6272 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6275 * Hitachi SH7000 and E7000-PC ICE support
6277 There is now support for communicating with the Hitachi E7000-PC ICE.
6278 This is available automatically when GDB is configured for the SH.
6282 As usual, a variety of small fixes and improvements, both generic
6283 and configuration-specific. See the ChangeLog for more detail.
6285 *** Changes in GDB-4.12:
6287 * Irix 5 is now supported
6291 GDB-4.12 on the HPPA has a number of changes which make it unable
6292 to debug the output from the currently released versions of GCC and
6293 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6294 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6295 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6298 *** Changes in GDB-4.11:
6300 * User visible changes:
6304 The "set remotedebug" option is now consistent between the mips remote
6305 target, remote targets using the gdb-specific protocol, UDI (AMD's
6306 debug protocol for the 29k) and the 88k bug monitor. It is now an
6307 integer specifying a debug level (normally 0 or 1, but 2 means more
6308 debugging info for the mips target).
6310 * DEC Alpha native support
6312 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6313 debug info, but GDB works fairly well with the DEC compiler and should
6314 work with a future GCC release. See the README file for a few
6315 Alpha-specific notes.
6317 * Preliminary thread implementation
6319 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6321 * LynxOS native and target support for 386
6323 This release has been hosted on LynxOS 2.2, and also can be configured
6324 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6327 * Improvements in C++ mangling/demangling.
6329 This release has much better g++ debugging, specifically in name
6330 mangling/demangling, virtual function calls, print virtual table,
6331 call methods, ...etc.
6333 *** Changes in GDB-4.10:
6335 * User visible changes:
6337 Remote debugging using the GDB-specific (`target remote') protocol now
6338 supports the `load' command. This is only useful if you have some
6339 other way of getting the stub to the target system, and you can put it
6340 somewhere in memory where it won't get clobbered by the download.
6342 Filename completion now works.
6344 When run under emacs mode, the "info line" command now causes the
6345 arrow to point to the line specified. Also, "info line" prints
6346 addresses in symbolic form (as well as hex).
6348 All vxworks based targets now support a user settable option, called
6349 vxworks-timeout. This option represents the number of seconds gdb
6350 should wait for responses to rpc's. You might want to use this if
6351 your vxworks target is, perhaps, a slow software simulator or happens
6352 to be on the far side of a thin network line.
6356 This release contains support for using a DEC alpha as a GDB host for
6357 cross debugging. Native alpha debugging is not supported yet.
6360 *** Changes in GDB-4.9:
6364 This is the first GDB release which is accompanied by a matching testsuite.
6365 The testsuite requires installation of dejagnu, which should be available
6366 via ftp from most sites that carry GNU software.
6370 'Cfront' style demangling has had its name changed to 'ARM' style, to
6371 emphasize that it was written from the specifications in the C++ Annotated
6372 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6373 disclaimers, it still generated too much confusion with users attempting to
6374 use gdb with AT&T cfront.
6378 GDB now uses a standard remote interface to a simulator library.
6379 So far, the library contains simulators for the Zilog Z8001/2, the
6380 Hitachi H8/300, H8/500 and Super-H.
6382 * New targets supported
6384 H8/300 simulator h8300-hitachi-hms or h8300hms
6385 H8/500 simulator h8500-hitachi-hms or h8500hms
6386 SH simulator sh-hitachi-hms or sh
6387 Z8000 simulator z8k-zilog-none or z8ksim
6388 IDT MIPS board over serial line mips-idt-ecoff
6390 Cross-debugging to GO32 targets is supported. It requires a custom
6391 version of the i386-stub.c module which is integrated with the
6392 GO32 memory extender.
6394 * New remote protocols
6396 MIPS remote debugging protocol.
6398 * New source languages supported
6400 This version includes preliminary support for Chill, a Pascal like language
6401 used by telecommunications companies. Chill support is also being integrated
6402 into the GNU compiler, but we don't know when it will be publically available.
6405 *** Changes in GDB-4.8:
6407 * HP Precision Architecture supported
6409 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6410 version of this support was available as a set of patches from the
6411 University of Utah. GDB does not support debugging of programs
6412 compiled with the HP compiler, because HP will not document their file
6413 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6414 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6416 Many problems in the preliminary version have been fixed.
6418 * Faster and better demangling
6420 We have improved template demangling and fixed numerous bugs in the GNU style
6421 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6422 character types (wchar_t) are now supported. Demangling of each symbol is now
6423 only done once, and is cached when the symbol table for a file is read in.
6424 This results in a small increase in memory usage for C programs, a moderate
6425 increase in memory usage for C++ programs, and a fantastic speedup in
6428 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6429 from the specifications in the Annotated Reference Manual, which AT&T's
6430 compiler does not actually implement.
6432 * G++ multiple inheritance compiler problem
6434 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6435 inheritance lattices was reworked to properly discover ambiguities. We
6436 recently found an example which causes this new algorithm to fail in a
6437 very subtle way, producing bad debug information for those classes.
6438 The file 'gcc.patch' (in this directory) can be applied to gcc to
6439 circumvent the problem. A future GCC release will contain a complete
6442 The previous G++ debug info problem (mentioned below for the gdb-4.7
6443 release) is fixed in gcc version 2.3.2.
6445 * Improved configure script
6447 The `configure' script will now attempt to guess your system type if
6448 you don't supply a host system type. The old scheme of supplying a
6449 host system triplet is preferable over using this. All the magic is
6450 done in the new `config.guess' script. Examine it for details.
6452 We have also brought our configure script much more in line with the FSF's
6453 version. It now supports the --with-xxx options. In particular,
6454 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6455 The resulting GDB will not be able to read arbitrary object file formats --
6456 only the format ``expected'' to be used on the configured target system.
6457 We hope to make this the default in a future release.
6459 * Documentation improvements
6461 There's new internal documentation on how to modify GDB, and how to
6462 produce clean changes to the code. We implore people to read it
6463 before submitting changes.
6465 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6466 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6467 `info' files are also provided. To build `info' files from scratch,
6468 you will need the latest `makeinfo' release, which will be available in
6469 a future texinfo-X.Y release.
6471 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6472 We're not sure exactly which versions have this problem, but it has
6473 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6474 or better. If that isn't possible, there is a patch in
6475 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6476 around this problem.
6480 GDB now supports array constants that can be used in expressions typed in by
6481 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6482 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6485 The new directory `gdb/sparclite' contains a program that demonstrates
6486 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6488 * New native hosts supported
6490 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6491 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6493 * New targets supported
6495 AMD 29k family via UDI a29k-amd-udi or udi29k
6497 * New file formats supported
6499 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6500 HPUX core files, and SCO 3.2v2 core files.
6504 Attaching to processes now works again; thanks for the many bug reports.
6506 We have also stomped on a bunch of core dumps caused by
6507 printf_filtered("%s") problems.
6509 We eliminated a copyright problem on the rpc and ptrace header files
6510 for VxWorks, which was discovered at the last minute during the 4.7
6511 release. You should now be able to build a VxWorks GDB.
6513 You can now interrupt gdb while an attached process is running. This
6514 will cause the attached process to stop, and give control back to GDB.
6516 We fixed problems caused by using too many file descriptors
6517 for reading symbols from object files and libraries. This was
6518 especially a problem for programs that used many (~100) shared
6521 The `step' command now only enters a subroutine if there is line number
6522 information for the subroutine. Otherwise it acts like the `next'
6523 command. Previously, `step' would enter subroutines if there was
6524 any debugging information about the routine. This avoids problems
6525 when using `cc -g1' on MIPS machines.
6527 * Internal improvements
6529 GDB's internal interfaces have been improved to make it easier to support
6530 debugging of multiple languages in the future.
6532 GDB now uses a common structure for symbol information internally.
6533 Minimal symbols (derived from linkage symbols in object files), partial
6534 symbols (from a quick scan of debug information), and full symbols
6535 contain a common subset of information, making it easier to write
6536 shared code that handles any of them.
6538 * New command line options
6540 We now accept --silent as an alias for --quiet.
6544 The memory-mapped-malloc library is now licensed under the GNU Library
6545 General Public License.
6547 *** Changes in GDB-4.7:
6549 * Host/native/target split
6551 GDB has had some major internal surgery to untangle the support for
6552 hosts and remote targets. Now, when you configure GDB for a remote
6553 target, it will no longer load in all of the support for debugging
6554 local programs on the host. When fully completed and tested, this will
6555 ensure that arbitrary host/target combinations are possible.
6557 The primary conceptual shift is to separate the non-portable code in
6558 GDB into three categories. Host specific code is required any time GDB
6559 is compiled on that host, regardless of the target. Target specific
6560 code relates to the peculiarities of the target, but can be compiled on
6561 any host. Native specific code is everything else: it can only be
6562 built when the host and target are the same system. Child process
6563 handling and core file support are two common `native' examples.
6565 GDB's use of /proc for controlling Unix child processes is now cleaner.
6566 It has been split out into a single module under the `target_ops' vector,
6567 plus two native-dependent functions for each system that uses /proc.
6569 * New hosts supported
6571 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6572 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6573 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6575 * New targets supported
6577 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6578 68030 and CPU32 m68030-*-*, m68332-*-*
6580 * New native hosts supported
6582 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6583 (386bsd is not well tested yet)
6584 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6586 * New file formats supported
6588 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6589 supports reading of `a.out.adobe' object files, which are an a.out
6590 format extended with minimal information about multiple sections.
6594 `show copying' is the same as the old `info copying'.
6595 `show warranty' is the same as `info warrantee'.
6596 These were renamed for consistency. The old commands continue to work.
6598 `info handle' is a new alias for `info signals'.
6600 You can now define pre-command hooks, which attach arbitrary command
6601 scripts to any command. The commands in the hook will be executed
6602 prior to the user's command. You can also create a hook which will be
6603 executed whenever the program stops. See gdb.texinfo.
6607 We now deal with Cfront style name mangling, and can even extract type
6608 info from mangled symbols. GDB can automatically figure out which
6609 symbol mangling style your C++ compiler uses.
6611 Calling of methods and virtual functions has been improved as well.
6615 The crash that occured when debugging Sun Ansi-C compiled binaries is
6616 fixed. This was due to mishandling of the extra N_SO stabs output
6619 We also finally got Ultrix 4.2 running in house, and fixed core file
6620 support, with help from a dozen people on the net.
6622 John M. Farrell discovered that the reason that single-stepping was so
6623 slow on all of the Mips based platforms (primarily SGI and DEC) was
6624 that we were trying to demangle and lookup a symbol used for internal
6625 purposes on every instruction that was being stepped through. Changing
6626 the name of that symbol so that it couldn't be mistaken for a C++
6627 mangled symbol sped things up a great deal.
6629 Rich Pixley sped up symbol lookups in general by getting much smarter
6630 about when C++ symbol mangling is necessary. This should make symbol
6631 completion (TAB on the command line) much faster. It's not as fast as
6632 we'd like, but it's significantly faster than gdb-4.6.
6636 A new user controllable variable 'call_scratch_address' can
6637 specify the location of a scratch area to be used when GDB
6638 calls a function in the target. This is necessary because the
6639 usual method of putting the scratch area on the stack does not work
6640 in systems that have separate instruction and data spaces.
6642 We integrated changes to support the 29k UDI (Universal Debugger
6643 Interface), but discovered at the last minute that we didn't have all
6644 of the appropriate copyright paperwork. We are working with AMD to
6645 resolve this, and hope to have it available soon.
6649 We have sped up the remote serial line protocol, especially for targets
6650 with lots of registers. It now supports a new `expedited status' ('T')
6651 message which can be used in place of the existing 'S' status message.
6652 This allows the remote stub to send only the registers that GDB
6653 needs to make a quick decision about single-stepping or conditional
6654 breakpoints, eliminating the need to fetch the entire register set for
6655 each instruction being stepped through.
6657 The GDB remote serial protocol now implements a write-through cache for
6658 registers, only re-reading the registers if the target has run.
6660 There is also a new remote serial stub for SPARC processors. You can
6661 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6662 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6663 processor with a serial port.
6667 Configure.in files have become much easier to read and modify. A new
6668 `table driven' format makes it more obvious what configurations are
6669 supported, and what files each one uses.
6673 There is a new opcodes library which will eventually contain all of the
6674 disassembly routines and opcode tables. At present, it only contains
6675 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6676 disassembler (binutils/objdump) to share these routines.
6678 The libiberty library is now copylefted under the GNU Library General
6679 Public License. This allows more liberal use, and was done so libg++
6680 can use it. This makes no difference to GDB, since the Library License
6681 grants all the rights from the General Public License.
6685 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6686 reference to the stabs symbol info used by the debugger. It is (as far
6687 as we know) the only published document on this fascinating topic. We
6688 encourage you to read it, compare it to the stabs information on your
6689 system, and send improvements on the document in general (to
6690 bug-gdb@prep.ai.mit.edu).
6692 And, of course, many bugs have been fixed.
6695 *** Changes in GDB-4.6:
6697 * Better support for C++ function names
6699 GDB now accepts as input the "demangled form" of C++ overloaded function
6700 names and member function names, and can do command completion on such names
6701 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6702 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6703 Make use of command completion, it is your friend.
6705 GDB also now accepts a variety of C++ mangled symbol formats. They are
6706 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6707 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6708 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6709 for the list of formats.
6711 * G++ symbol mangling problem
6713 Recent versions of gcc have a bug in how they emit debugging information for
6714 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6715 directory) can be applied to gcc to fix the problem. Alternatively, if you
6716 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6717 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6718 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6721 * New 'maintenance' command
6723 All of the commands related to hacking GDB internals have been moved out of
6724 the main command set, and now live behind the 'maintenance' command. This
6725 can also be abbreviated as 'mt'. The following changes were made:
6727 dump-me -> maintenance dump-me
6728 info all-breakpoints -> maintenance info breakpoints
6729 printmsyms -> maintenance print msyms
6730 printobjfiles -> maintenance print objfiles
6731 printpsyms -> maintenance print psymbols
6732 printsyms -> maintenance print symbols
6734 The following commands are new:
6736 maintenance demangle Call internal GDB demangler routine to
6737 demangle a C++ link name and prints the result.
6738 maintenance print type Print a type chain for a given symbol
6740 * Change to .gdbinit file processing
6742 We now read the $HOME/.gdbinit file before processing the argv arguments
6743 (e.g. reading symbol files or core files). This allows global parameters to
6744 be set, which will apply during the symbol reading. The ./.gdbinit is still
6745 read after argv processing.
6747 * New hosts supported
6749 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6751 GNU/Linux support i386-unknown-linux or linux
6753 We are also including code to support the HP/PA running BSD and HPUX. This
6754 is almost guaranteed not to work, as we didn't have time to test or build it
6755 for this release. We are including it so that the more adventurous (or
6756 masochistic) of you can play with it. We also had major problems with the
6757 fact that the compiler that we got from HP doesn't support the -g option.
6760 * New targets supported
6762 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6764 * More smarts about finding #include files
6766 GDB now remembers the compilation directory for all include files, and for
6767 all files from which C is generated (like yacc and lex sources). This
6768 greatly improves GDB's ability to find yacc/lex sources, and include files,
6769 especially if you are debugging your program from a directory different from
6770 the one that contains your sources.
6772 We also fixed a bug which caused difficulty with listing and setting
6773 breakpoints in include files which contain C code. (In the past, you had to
6774 try twice in order to list an include file that you hadn't looked at before.)
6776 * Interesting infernals change
6778 GDB now deals with arbitrary numbers of sections, where the symbols for each
6779 section must be relocated relative to that section's landing place in the
6780 target's address space. This work was needed to support ELF with embedded
6781 stabs used by Solaris-2.0.
6783 * Bug fixes (of course!)
6785 There have been loads of fixes for the following things:
6786 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6787 i960, stabs, DOS(GO32), procfs, etc...
6789 See the ChangeLog for details.
6791 *** Changes in GDB-4.5:
6793 * New machines supported (host and target)
6795 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6797 SGI Irix-4.x mips-sgi-irix4 or iris4
6799 * New malloc package
6801 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6802 Mmalloc is capable of handling mutiple heaps of memory. It is also
6803 capable of saving a heap to a file, and then mapping it back in later.
6804 This can be used to greatly speedup the startup of GDB by using a
6805 pre-parsed symbol table which lives in a mmalloc managed heap. For
6806 more details, please read mmalloc/mmalloc.texi.
6810 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6811 'help info proc' for details.
6813 * MIPS ecoff symbol table format
6815 The code that reads MIPS symbol table format is now supported on all hosts.
6816 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6819 * File name changes for MS-DOS
6821 Many files in the config directories have been renamed to make it easier to
6822 support GDB on MS-DOSe systems (which have very restrictive file name
6823 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6824 environment) is close to working but has some remaining problems. Note
6825 that debugging of DOS programs is not supported, due to limitations
6826 in the ``operating system'', but it can be used to host cross-debugging.
6828 * Cross byte order fixes
6830 Many fixes have been made to support cross debugging of Sparc and MIPS
6831 targets from hosts whose byte order differs.
6833 * New -mapped and -readnow options
6835 If memory-mapped files are available on your system through the 'mmap'
6836 system call, you can use the -mapped option on the `file' or
6837 `symbol-file' commands to cause GDB to write the symbols from your
6838 program into a reusable file. If the program you are debugging is
6839 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6840 Future GDB debugging sessions will notice the presence of this file,
6841 and will quickly map in symbol information from it, rather than reading
6842 the symbol table from the executable program. Using the '-mapped'
6843 option in a GDB `file' or `symbol-file' command has the same effect as
6844 starting GDB with the '-mapped' command-line option.
6846 You can cause GDB to read the entire symbol table immediately by using
6847 the '-readnow' option with any of the commands that load symbol table
6848 information (or on the GDB command line). This makes the command
6849 slower, but makes future operations faster.
6851 The -mapped and -readnow options are typically combined in order to
6852 build a `fred.syms' file that contains complete symbol information.
6853 A simple GDB invocation to do nothing but build a `.syms' file for future
6856 gdb -batch -nx -mapped -readnow programname
6858 The `.syms' file is specific to the host machine on which GDB is run.
6859 It holds an exact image of GDB's internal symbol table. It cannot be
6860 shared across multiple host platforms.
6862 * longjmp() handling
6864 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6865 siglongjmp() without losing control. This feature has not yet been ported to
6866 all systems. It currently works on many 386 platforms, all MIPS-based
6867 platforms (SGI, DECstation, etc), and Sun3/4.
6871 Preliminary work has been put in to support the new Solaris OS from Sun. At
6872 this time, it can control and debug processes, but it is not capable of
6877 As always, many many bug fixes. The major areas were with g++, and mipsread.
6878 People using the MIPS-based platforms should experience fewer mysterious
6879 crashes and trashed symbol tables.
6881 *** Changes in GDB-4.4:
6883 * New machines supported (host and target)
6885 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6887 BSD Reno on Vax vax-dec-bsd
6888 Ultrix on Vax vax-dec-ultrix
6890 * New machines supported (target)
6892 AMD 29000 embedded, using EBMON a29k-none-none
6896 GDB continues to improve its handling of C++. `References' work better.
6897 The demangler has also been improved, and now deals with symbols mangled as
6898 per the Annotated C++ Reference Guide.
6900 GDB also now handles `stabs' symbol information embedded in MIPS
6901 `ecoff' symbol tables. Since the ecoff format was not easily
6902 extensible to handle new languages such as C++, this appeared to be a
6903 good way to put C++ debugging info into MIPS binaries. This option
6904 will be supported in the GNU C compiler, version 2, when it is
6907 * New features for SVR4
6909 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6910 shared libraries. Debugging dynamically linked programs should present
6911 only minor differences from debugging statically linked programs.
6913 The `info proc' command will print out information about any process
6914 on an SVR4 system (including the one you are debugging). At the moment,
6915 it prints the address mappings of the process.
6917 If you bring up GDB on another SVR4 system, please send mail to
6918 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6920 * Better dynamic linking support in SunOS
6922 Reading symbols from shared libraries which contain debugging symbols
6923 now works properly. However, there remain issues such as automatic
6924 skipping of `transfer vector' code during function calls, which
6925 make it harder to debug code in a shared library, than to debug the
6926 same code linked statically.
6930 GDB is now using the latest `getopt' routines from the FSF. This
6931 version accepts the -- prefix for options with long names. GDB will
6932 continue to accept the old forms (-option and +option) as well.
6933 Various single letter abbreviations for options have been explicity
6934 added to the option table so that they won't get overshadowed in the
6935 future by other options that begin with the same letter.
6939 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6940 Many assorted bugs have been handled. Many more remain to be handled.
6941 See the various ChangeLog files (primarily in gdb and bfd) for details.
6944 *** Changes in GDB-4.3:
6946 * New machines supported (host and target)
6948 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6949 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6950 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6952 * Almost SCO Unix support
6954 We had hoped to support:
6955 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6956 (except for core file support), but we discovered very late in the release
6957 that it has problems with process groups that render gdb unusable. Sorry
6958 about that. I encourage people to fix it and post the fixes.
6960 * Preliminary ELF and DWARF support
6962 GDB can read ELF object files on System V Release 4, and can handle
6963 debugging records for C, in DWARF format, in ELF files. This support
6964 is preliminary. If you bring up GDB on another SVR4 system, please
6965 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6970 GDB now uses the latest `readline' library. One user-visible change
6971 is that two tabs will list possible command completions, which previously
6972 required typing M-? (meta-question mark, or ESC ?).
6976 The `stepi' bug that many of you noticed has been squashed.
6977 Many bugs in C++ have been handled. Many more remain to be handled.
6978 See the various ChangeLog files (primarily in gdb and bfd) for details.
6980 * State of the MIPS world (in case you wondered):
6982 GDB can understand the symbol tables emitted by the compilers
6983 supplied by most vendors of MIPS-based machines, including DEC. These
6984 symbol tables are in a format that essentially nobody else uses.
6986 Some versions of gcc come with an assembler post-processor called
6987 mips-tfile. This program is required if you want to do source-level
6988 debugging of gcc-compiled programs. I believe FSF does not ship
6989 mips-tfile with gcc version 1, but it will eventually come with gcc
6992 Debugging of g++ output remains a problem. g++ version 1.xx does not
6993 really support it at all. (If you're lucky, you should be able to get
6994 line numbers and stack traces to work, but no parameters or local
6995 variables.) With some work it should be possible to improve the
6998 When gcc version 2 is released, you will have somewhat better luck.
6999 However, even then you will get confusing results for inheritance and
7002 We will eventually provide full debugging of g++ output on
7003 DECstations. This will probably involve some kind of stabs-in-ecoff
7004 encapulation, but the details have not been worked out yet.
7007 *** Changes in GDB-4.2:
7009 * Improved configuration
7011 Only one copy of `configure' exists now, and it is not self-modifying.
7012 Porting BFD is simpler.
7016 The `step' and `next' commands now only stop at the first instruction
7017 of a source line. This prevents the multiple stops that used to occur
7018 in switch statements, for-loops, etc. `Step' continues to stop if a
7019 function that has debugging information is called within the line.
7023 Lots of small bugs fixed. More remain.
7025 * New host supported (not target)
7027 Intel 386 PC clone running Mach i386-none-mach
7030 *** Changes in GDB-4.1:
7032 * Multiple source language support
7034 GDB now has internal scaffolding to handle several source languages.
7035 It determines the type of each source file from its filename extension,
7036 and will switch expression parsing and number formatting to match the
7037 language of the function in the currently selected stack frame.
7038 You can also specifically set the language to be used, with
7039 `set language c' or `set language modula-2'.
7043 GDB now has preliminary support for the GNU Modula-2 compiler,
7044 currently under development at the State University of New York at
7045 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7046 continue through the fall of 1991 and into 1992.
7048 Other Modula-2 compilers are currently not supported, and attempting to
7049 debug programs compiled with them will likely result in an error as the
7050 symbol table is read. Feel free to work on it, though!
7052 There are hooks in GDB for strict type checking and range checking,
7053 in the `Modula-2 philosophy', but they do not currently work.
7057 GDB can now write to executable and core files (e.g. patch
7058 a variable's value). You must turn this switch on, specify
7059 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7060 by assigning a new value to a variable. Modifications take
7063 * Automatic SunOS shared library reading
7065 When you run your program, GDB automatically determines where its
7066 shared libraries (if any) have been loaded, and reads their symbols.
7067 The `share' command is no longer needed. This also works when
7068 examining core files.
7072 You can specify the number of lines that the `list' command shows.
7075 * New machines supported (host and target)
7077 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7078 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7079 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7081 * New hosts supported (not targets)
7083 IBM RT/PC: romp-ibm-aix or rtpc
7085 * New targets supported (not hosts)
7087 AMD 29000 embedded with COFF a29k-none-coff
7088 AMD 29000 embedded with a.out a29k-none-aout
7089 Ultracomputer remote kernel debug a29k-nyu-kern
7091 * New remote interfaces
7097 *** Changes in GDB-4.0:
7101 Wide output is wrapped at good places to make the output more readable.
7103 Gdb now supports cross-debugging from a host machine of one type to a
7104 target machine of another type. Communication with the target system
7105 is over serial lines. The ``target'' command handles connecting to the
7106 remote system; the ``load'' command will download a program into the
7107 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7108 also supports debugging of realtime processes running under VxWorks,
7109 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7110 stub on the target system.
7112 New CPUs supported include the AMD 29000 and Intel 960.
7114 GDB now reads object files and symbol tables via a ``binary file''
7115 library, which allows a single copy of GDB to debug programs of multiple
7116 object file types such as a.out and coff.
7118 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7119 refcard.dvi and refcard.ps are available to format it).
7122 * Control-Variable user interface simplified
7124 All variables that control the operation of the debugger can be set
7125 by the ``set'' command, and displayed by the ``show'' command.
7127 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7128 ``Show prompt'' produces the response:
7129 Gdb's prompt is new-gdb=>.
7131 What follows are the NEW set commands. The command ``help set'' will
7132 print a complete list of old and new set commands. ``help set FOO''
7133 will give a longer description of the variable FOO. ``show'' will show
7134 all of the variable descriptions and their current settings.
7136 confirm on/off: Enables warning questions for operations that are
7137 hard to recover from, e.g. rerunning the program while
7138 it is already running. Default is ON.
7140 editing on/off: Enables EMACS style command line editing
7141 of input. Previous lines can be recalled with
7142 control-P, the current line can be edited with control-B,
7143 you can search for commands with control-R, etc.
7146 history filename NAME: NAME is where the gdb command history
7147 will be stored. The default is .gdb_history,
7148 or the value of the environment variable
7151 history size N: The size, in commands, of the command history. The
7152 default is 256, or the value of the environment variable
7155 history save on/off: If this value is set to ON, the history file will
7156 be saved after exiting gdb. If set to OFF, the
7157 file will not be saved. The default is OFF.
7159 history expansion on/off: If this value is set to ON, then csh-like
7160 history expansion will be performed on
7161 command line input. The default is OFF.
7163 radix N: Sets the default radix for input and output. It can be set
7164 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7165 in the current radix, so "set radix 10" is always a no-op.
7167 height N: This integer value is the number of lines on a page. Default
7168 is 24, the current `stty rows'' setting, or the ``li#''
7169 setting from the termcap entry matching the environment
7172 width N: This integer value is the number of characters on a line.
7173 Default is 80, the current `stty cols'' setting, or the ``co#''
7174 setting from the termcap entry matching the environment
7177 Note: ``set screensize'' is obsolete. Use ``set height'' and
7178 ``set width'' instead.
7180 print address on/off: Print memory addresses in various command displays,
7181 such as stack traces and structure values. Gdb looks
7182 more ``symbolic'' if you turn this off; it looks more
7183 ``machine level'' with it on. Default is ON.
7185 print array on/off: Prettyprint arrays. New convenient format! Default
7188 print demangle on/off: Print C++ symbols in "source" form if on,
7191 print asm-demangle on/off: Same, for assembler level printouts
7194 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7197 * Support for Epoch Environment.
7199 The epoch environment is a version of Emacs v18 with windowing. One
7200 new command, ``inspect'', is identical to ``print'', except that if you
7201 are running in the epoch environment, the value is printed in its own
7205 * Support for Shared Libraries
7207 GDB can now debug programs and core files that use SunOS shared libraries.
7208 Symbols from a shared library cannot be referenced
7209 before the shared library has been linked with the program (this
7210 happens after you type ``run'' and before the function main() is entered).
7211 At any time after this linking (including when examining core files
7212 from dynamically linked programs), gdb reads the symbols from each
7213 shared library when you type the ``sharedlibrary'' command.
7214 It can be abbreviated ``share''.
7216 sharedlibrary REGEXP: Load shared object library symbols for files
7217 matching a unix regular expression. No argument
7218 indicates to load symbols for all shared libraries.
7220 info sharedlibrary: Status of loaded shared libraries.
7225 A watchpoint stops execution of a program whenever the value of an
7226 expression changes. Checking for this slows down execution
7227 tremendously whenever you are in the scope of the expression, but is
7228 quite useful for catching tough ``bit-spreader'' or pointer misuse
7229 problems. Some machines such as the 386 have hardware for doing this
7230 more quickly, and future versions of gdb will use this hardware.
7232 watch EXP: Set a watchpoint (breakpoint) for an expression.
7234 info watchpoints: Information about your watchpoints.
7236 delete N: Deletes watchpoint number N (same as breakpoints).
7237 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7238 enable N: Re-enables watchpoint number N (same as breakpoints).
7241 * C++ multiple inheritance
7243 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7246 * C++ exception handling
7248 Gdb now supports limited C++ exception handling. Besides the existing
7249 ability to breakpoint on an exception handler, gdb can breakpoint on
7250 the raising of an exception (before the stack is peeled back to the
7253 catch FOO: If there is a FOO exception handler in the dynamic scope,
7254 set a breakpoint to catch exceptions which may be raised there.
7255 Multiple exceptions (``catch foo bar baz'') may be caught.
7257 info catch: Lists all exceptions which may be caught in the
7258 current stack frame.
7261 * Minor command changes
7263 The command ``call func (arg, arg, ...)'' now acts like the print
7264 command, except it does not print or save a value if the function's result
7265 is void. This is similar to dbx usage.
7267 The ``up'' and ``down'' commands now always print the frame they end up
7268 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7269 frames without printing.
7271 * New directory command
7273 'dir' now adds directories to the FRONT of the source search path.
7274 The path starts off empty. Source files that contain debug information
7275 about the directory in which they were compiled can be found even
7276 with an empty path; Sun CC and GCC include this information. If GDB can't
7277 find your source file in the current directory, type "dir .".
7279 * Configuring GDB for compilation
7281 For normal use, type ``./configure host''. See README or gdb.texinfo
7284 GDB now handles cross debugging. If you are remotely debugging between
7285 two different machines, type ``./configure host -target=targ''.
7286 Host is the machine where GDB will run; targ is the machine
7287 where the program that you are debugging will run.