gdb.texinfo

这个是LINUX下的GDB调度工具的源码

@cindex @code{--epoch}
The Epoch Emacs-@value{GDBN} interface sets this option when it runs
@value{GDBN} as a subprocess.  It tells @value{GDBN} to modify its print
routines so as to allow Epoch to display values of expressions in a
separate window.

@item -annotate @var{level}
@cindex @code{--annotate}
This option sets the @dfn{annotation level} inside @value{GDBN}.  Its
effect is identical to using @samp{set annotate @var{level}}
(@pxref{Annotations}).  The annotation @var{level} controls how much
information @value{GDBN} prints together with its prompt, values of
expressions, source lines, and other types of output.  Level 0 is the
normal, level 1 is for use when @value{GDBN} is run as a subprocess of
@sc{gnu} Emacs, level 3 is the maximum annotation suitable for programs
that control @value{GDBN}, and level 2 has been deprecated.

The annotation mechanism has largely been superseeded by @sc{gdb/mi}
(@pxref{GDB/MI}).

@item --args
@cindex @code{--args}
Change interpretation of command line so that arguments following the
executable file are passed as command line arguments to the inferior.
This option stops option processing.

@item -baud @var{bps}
@itemx -b @var{bps}
@cindex @code{--baud}
@cindex @code{-b}
Set the line speed (baud rate or bits per second) of any serial
interface used by @value{GDBN} for remote debugging.

@item -tty @var{device}
@itemx -t @var{device}
@cindex @code{--tty}
@cindex @code{-t}
Run using @var{device} for your program's standard input and output.
@c FIXME: kingdon thinks there is more to -tty.  Investigate.

@c resolve the situation of these eventually
@item -tui
@cindex @code{--tui}
Activate the @dfn{Text User Interface} when starting.  The Text User
Interface manages several text windows on the terminal, showing
source, assembly, registers and @value{GDBN} command outputs
(@pxref{TUI, ,@value{GDBN} Text User Interface}).  Alternatively, the
Text User Interface can be enabled by invoking the program
@samp{gdbtui}.  Do not use this option if you run @value{GDBN} from
Emacs (@pxref{Emacs, ,Using @value{GDBN} under @sc{gnu} Emacs}).

@c @item -xdb
@c @cindex @code{--xdb}
@c Run in XDB compatibility mode, allowing the use of certain XDB commands.
@c For information, see the file @file{xdb_trans.html}, which is usually
@c installed in the directory @code{/opt/langtools/wdb/doc} on HP-UX
@c systems.

@item -interpreter @var{interp}
@cindex @code{--interpreter}
Use the interpreter @var{interp} for interface with the controlling
program or device.  This option is meant to be set by programs which
communicate with @value{GDBN} using it as a back end.
@xref{Interpreters, , Command Interpreters}.

@samp{--interpreter=mi} (or @samp{--interpreter=mi2}) causes
@value{GDBN} to use the @dfn{@sc{gdb/mi} interface} (@pxref{GDB/MI, ,
The @sc{gdb/mi} Interface}) included since @var{GDBN} version 6.0.  The
previous @sc{gdb/mi} interface, included in @value{GDBN} version 5.3 and
selected with @samp{--interpreter=mi1}, is deprecated.  Earlier
@sc{gdb/mi} interfaces are no longer supported.

@item -write
@cindex @code{--write}
Open the executable and core files for both reading and writing.  This
is equivalent to the @samp{set write on} command inside @value{GDBN}
(@pxref{Patching}).

@item -statistics
@cindex @code{--statistics}
This option causes @value{GDBN} to print statistics about time and
memory usage after it completes each command and returns to the prompt.

@item -version
@cindex @code{--version}
This option causes @value{GDBN} to print its version number and
no-warranty blurb, and exit.

@end table

@node Quitting GDB
@section Quitting @value{GDBN}
@cindex exiting @value{GDBN}
@cindex leaving @value{GDBN}

@table @code
@kindex quit @r{[}@var{expression}@r{]}
@kindex q @r{(@code{quit})}
@item quit @r{[}@var{expression}@r{]}
@itemx q
To exit @value{GDBN}, use the @code{quit} command (abbreviated
@code{q}), or type an end-of-file character (usually @kbd{C-d}).  If you
do not supply @var{expression}, @value{GDBN} will terminate normally;
otherwise it will terminate using the result of @var{expression} as the
error code.
@end table

@cindex interrupt
An interrupt (often @kbd{C-c}) does not exit from @value{GDBN}, but rather
terminates the action of any @value{GDBN} command that is in progress and
returns to @value{GDBN} command level.  It is safe to type the interrupt
character at any time because @value{GDBN} does not allow it to take effect
until a time when it is safe.

If you have been using @value{GDBN} to control an attached process or
device, you can release it with the @code{detach} command
(@pxref{Attach, ,Debugging an already-running process}).

@node Shell Commands
@section Shell commands

If you need to execute occasional shell commands during your
debugging session, there is no need to leave or suspend @value{GDBN}; you can
just use the @code{shell} command.

@table @code
@kindex shell
@cindex shell escape
@item shell @var{command string}
Invoke a standard shell to execute @var{command string}.
If it exists, the environment variable @code{SHELL} determines which
shell to run.  Otherwise @value{GDBN} uses the default shell
(@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.).
@end table

The utility @code{make} is often needed in development environments.
You do not have to use the @code{shell} command for this purpose in
@value{GDBN}:

@table @code
@kindex make
@cindex calling make
@item make @var{make-args}
Execute the @code{make} program with the specified
arguments.  This is equivalent to @samp{shell make @var{make-args}}.
@end table

@node Logging output
@section Logging output
@cindex logging @value{GDBN} output

You may want to save the output of @value{GDBN} commands to a file.
There are several commands to control @value{GDBN}'s logging.

@table @code
@kindex set logging
@item set logging on
Enable logging.
@item set logging off
Disable logging.
@item set logging file @var{file}
Change the name of the current logfile.  The default logfile is @file{gdb.txt}.
@item set logging overwrite [on|off]
By default, @value{GDBN} will append to the logfile.  Set @code{overwrite} if
you want @code{set logging on} to overwrite the logfile instead.
@item set logging redirect [on|off]
By default, @value{GDBN} output will go to both the terminal and the logfile.
Set @code{redirect} if you want output to go only to the log file.
@kindex show logging
@item show logging
Show the current values of the logging settings.
@end table

@node Commands
@chapter @value{GDBN} Commands

You can abbreviate a @value{GDBN} command to the first few letters of the command
name, if that abbreviation is unambiguous; and you can repeat certain
@value{GDBN} commands by typing just @key{RET}.  You can also use the @key{TAB}
key to get @value{GDBN} to fill out the rest of a word in a command (or to
show you the alternatives available, if there is more than one possibility).

@menu
* Command Syntax::              How to give commands to @value{GDBN}
* Completion::                  Command completion
* Help::                        How to ask @value{GDBN} for help
@end menu

@node Command Syntax
@section Command syntax

A @value{GDBN} command is a single line of input.  There is no limit on
how long it can be.  It starts with a command name, which is followed by
arguments whose meaning depends on the command name.  For example, the
command @code{step} accepts an argument which is the number of times to
step, as in @samp{step 5}.  You can also use the @code{step} command
with no arguments.  Some commands do not allow any arguments.

@cindex abbreviation
@value{GDBN} command names may always be truncated if that abbreviation is
unambiguous.  Other possible command abbreviations are listed in the
documentation for individual commands.  In some cases, even ambiguous
abbreviations are allowed; for example, @code{s} is specially defined as
equivalent to @code{step} even though there are other commands whose
names start with @code{s}.  You can test abbreviations by using them as
arguments to the @code{help} command.

@cindex repeating commands
@kindex RET @r{(repeat last command)}
A blank line as input to @value{GDBN} (typing just @key{RET}) means to
repeat the previous command.  Certain commands (for example, @code{run})
will not repeat this way; these are commands whose unintentional
repetition might cause trouble and which you are unlikely to want to
repeat.

The @code{list} and @code{x} commands, when you repeat them with
@key{RET}, construct new arguments rather than repeating
exactly as typed.  This permits easy scanning of source or memory.

@value{GDBN} can also use @key{RET} in another way: to partition lengthy
output, in a way similar to the common utility @code{more}
(@pxref{Screen Size,,Screen size}).  Since it is easy to press one
@key{RET} too many in this situation, @value{GDBN} disables command
repetition after any command that generates this sort of display.

@kindex # @r{(a comment)}
@cindex comment
Any text from a @kbd{#} to the end of the line is a comment; it does
nothing.  This is useful mainly in command files (@pxref{Command
Files,,Command files}).

@cindex repeating command sequences
@kindex C-o @r{(operate-and-get-next)}
The @kbd{C-o} binding is useful for repeating a complex sequence of
commands.  This command accepts the current line, like @kbd{RET}, and
then fetches the next line relative to the current line from the history
for editing.

@node Completion
@section Command completion

@cindex completion
@cindex word completion
@value{GDBN} can fill in the rest of a word in a command for you, if there is
only one possibility; it can also show you what the valid possibilities
are for the next word in a command, at any time.  This works for @value{GDBN}
commands, @value{GDBN} subcommands, and the names of symbols in your program.

Press the @key{TAB} key whenever you want @value{GDBN} to fill out the rest
of a word.  If there is only one possibility, @value{GDBN} fills in the
word, and waits for you to finish the command (or press @key{RET} to
enter it).  For example, if you type

@c FIXME "@key" does not distinguish its argument sufficiently to permit
@c complete accuracy in these examples; space introduced for clarity.
@c If texinfo enhancements make it unnecessary, it would be nice to
@c replace " @key" by "@key" in the following...
@smallexample
(@value{GDBP}) info bre @key{TAB}
@end smallexample

@noindent
@value{GDBN} fills in the rest of the word @samp{breakpoints}, since that is
the only @code{info} subcommand beginning with @samp{bre}:

@smallexample
(@value{GDBP}) info breakpoints
@end smallexample

@noindent
You can either press @key{RET} at this point, to run the @code{info
breakpoints} command, or backspace and enter something else, if
@samp{breakpoints} does not look like the command you expected.  (If you
were sure you wanted @code{info breakpoints} in the first place, you
might as well just type @key{RET} immediately after @samp{info bre},
to exploit command abbreviations rather than command completion).

If there is more than one possibility for the next word when you press
@key{TAB}, @value{GDBN} sounds a bell.  You can either supply more
characters and try again, or just press @key{TAB} a second time;
@value{GDBN} displays all the possible completions for that word.  For
example, you might want to set a breakpoint on a subroutine whose name
begins with @samp{make_}, but when you type @kbd{b make_@key{TAB}} @value{GDBN}
just sounds the bell.  Typing @key{TAB} again displays all the
function names in your program that begin with those characters, for
example:

@smallexample
(@value{GDBP}) b make_ @key{TAB}
@exdent @value{GDBN} sounds bell; press @key{TAB} again, to see:
make_a_section_from_file     make_environ
make_abs_section             make_function_type
make_blockvector             make_pointer_type
make_cleanup                 make_reference_type
make_command                 make_symbol_completion_list
(@value{GDBP}) b make_
@end smallexample

@noindent
After displaying the available possibilities, @value{GDBN} copies your
partial input (@samp{b make_} in the example) so you can finish the
command.

If you just want to see the list of alternatives in the first place, you
can press @kbd{M-?} rather than pressing @key{TAB} twice.  @kbd{M-?}
means @kbd{@key{META} ?}.  You can type this either by holding down a
key designated as the @key{META} shift on your keyboard (if there is
one) while typing @kbd{?}, or as @key{ESC} followed by @kbd{?}.

@cindex quotes in commands
@cindex completion of quoted strings
Sometimes the string you need, while logically a ``word'', may contain
parentheses or other characters that @value{GDBN} normally excludes from
its notion of a word.  To permit word completion to work in this
situation, you may enclose words in @code{'} (single quote marks) in
@value{GDBN} commands.

The most likely situation where you might need this is in typing the
name of a C@t{++} function.  This is because C@t{++} allows function
overloading (multiple definitions of the same function, distinguished
by argument type).  For example, when you want to set a breakpoint you
may need to distinguish whether you mean the version of @code{name}
that takes an @code{int} parameter, @code{name(int)}, or the version
that takes a @code{float} parameter, @code{name(float)}.  To use the
word-completion facilities in this situation, type a single quote
@code{'} at the beginning of the function name.  This alerts
@value{GDBN} that it may need to consider more information than usual
when you press @key{TAB} or @kbd{M-?} to request word completion:

@smallexample
(@value{GDBP}) b 'bubble( @kbd{M-?}
bubble(double,double)    bubble(int,int)
(@value{GDBP}) b 'bubble(
@end smallexample

In some cases, @value{GDBN} can tell that completing a name requires using
quotes.  When this happens, @value{GDBN} inserts the quote for you (while
completing as much as it can) if you do not type the quote in the first
place:

@smallexample
(@value{GDBP}) b bub @key{TAB}
@exdent @value{GDBN} alters your input line to the following, and rings a bell:
(@value{GDBP}) b 'bubble(
@end smallexample

@noindent
In general, @value{GDBN} can tell that a quote is needed (and inserts it) if
you have not yet started typing the argument list when you ask for