-@c Copyright (c) 1999, 2000, 2001, 2002, 2003, 2004
+@c Copyright (c) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
@c Free Software Foundation, Inc.
@c This is part of the CPP and GCC manuals.
@c For copying conditions, see the file gcc.texi.
Predefine @var{name} as a macro, with definition @code{1}.
@item -D @var{name}=@var{definition}
-Predefine @var{name} as a macro, with definition @var{definition}.
-There are no restrictions on the contents of @var{definition}, but if
-you are invoking the preprocessor from a shell or shell-like program you
-may need to use the shell's quoting syntax to protect characters such as
-spaces that have a meaning in the shell syntax.
+The contents of @var{definition} are tokenized and processed as if
+they appeared during translation phase three in a @samp{#define}
+directive. In particular, the definition will be truncated by
+embedded newline characters.
+
+If you are invoking the preprocessor from a shell or shell-like
+program you may need to use the shell's quoting syntax to protect
+characters such as spaces that have a meaning in the shell syntax.
If you wish to define a function-like macro on the command line, write
its argument list with surrounding parentheses before the equals sign
(@pxref{System Headers})
@end ifset
.
+If @var{dir} begins with @code{=}, then the @code{=} will be replaced
+by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
@item -o @var{file}
@opindex o
@xref{Traditional Mode}.
@end ifset
-@item -Wimport
-@opindex Wimport
-Warn the first time @samp{#import} is used.
-
@item -Wundef
@opindex Wundef
Warn whenever an identifier which is not a macro is encountered in an
Built-in macros, macros defined on the command line, and macros
defined in include files are not warned about.
-@strong{Note:} If a macro is actually used, but only used in skipped
+@emph{Note:} If a macro is actually used, but only used in skipped
conditional blocks, then CPP will report it as unused. To avoid the
warning in such a case, you might improve the scope of the macro's
definition by, for example, moving it into the first skipped block.
@option{-imacros} command line options.
Unless specified explicitly (with @option{-MT} or @option{-MQ}), the
-object file name consists of the basename of the source file with any
-suffix replaced with object file suffix. If there are many included
-files then the rule is split into several lines using @samp{\}-newline.
-The rule has no commands.
+object file name consists of the name of the source file with any
+suffix replaced with object file suffix and with any leading directory
+parts removed. If there are many included files then the rule is
+split into several lines using @samp{\}-newline. The rule has no
+commands.
This option does not suppress the preprocessor's debug output, such as
@option{-dM}. To avoid mixing such debug output with the dependency
@opindex MT
Change the target of the rule emitted by dependency generation. By
-default CPP takes the name of the main input file, including any path,
-deletes any file suffix such as @samp{.c}, and appends the platform's
-usual object suffix. The result is the target.
+default CPP takes the name of the main input file, deletes any
+directory components and any file suffix such as @samp{.c}, and
+appends the platform's usual object suffix. The result is the target.
An @option{-MT} option will set the target to be exactly the string you
specify. If you want multiple targets, you can specify them as a single
@option{-MD} is equivalent to @option{-M -MF @var{file}}, except that
@option{-E} is not implied. The driver determines @var{file} based on
whether an @option{-o} option is given. If it is, the driver uses its
-argument but with a suffix of @file{.d}, otherwise it take the
-basename of the input file and applies a @file{.d} suffix.
+argument but with a suffix of @file{.d}, otherwise it takes the name
+of the input file, removes any directory components and suffix, and
+applies a @file{.d} suffix.
If @option{-MD} is used in conjunction with @option{-E}, any
@option{-o} switch is understood to specify the dependency output file
-(but @pxref{dashMF,,-MF}), but if used without @option{-E}, each @option{-o}
+(@pxref{dashMF,,-MF}), but if used without @option{-E}, each @option{-o}
is understood to specify a target object file.
Since @option{-E} is not implied, @option{-MD} can be used to generate
@item -MMD
@opindex MMD
Like @option{-MD} except mention only user header files, not system
--header files.
+header files.
@ifclear cppmanual
@item -fpch-deps
create it because those files are not consulted when a precompiled
header is used.
+@item -fpch-preprocess
+@opindex fpch-preprocess
+This option allows use of a precompiled header (@pxref{Precompiled
+Headers}) together with @option{-E}. It inserts a special @code{#pragma},
+@code{#pragma GCC pch_preprocess "<filename>"} in the output to mark
+the place where the precompiled header was found, and its filename. When
+@option{-fpreprocessed} is in use, GCC recognizes this @code{#pragma} and
+loads the PCH@.
+
+This option is off by default, because the resulting preprocessed output
+is only really suitable as input to GCC@. It is switched on by
+@option{-save-temps}.
+
+You should not write this @code{#pragma} in your own code, but it is
+safe to edit the filename if the PCH file is available in a different
+location. The filename may be absolute or it may be relative to GCC's
+current directory.
+
@end ifclear
@item -x c
@itemx -x c++
recognize the extension, it will treat the file as C; this is the most
generic mode.
-@strong{Note:} Previous versions of cpp accepted a @option{-lang} option
+@emph{Note:} Previous versions of cpp accepted a @option{-lang} option
which selected both the language and the standards conformance level.
This option has been removed, because it conflicts with the @option{-l}
option.
Search @var{dir} for header files, but do it @emph{after} all
directories specified with @option{-I} and the standard system directories
have been exhausted. @var{dir} is treated as a system include directory.
+If @var{dir} begins with @code{=}, then the @code{=} will be replaced
+by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
@item -iprefix @var{prefix}
@opindex iprefix
path. @option{-iwithprefixbefore} puts it in the same place @option{-I}
would; @option{-iwithprefix} puts it where @option{-idirafter} would.
+@item -isysroot @var{dir}
+@opindex isysroot
+This option is like the @option{--sysroot} option, but applies only to
+header files. See the @option{--sysroot} option for more information.
+
+@item -imultilib @var{dir}
+@opindex imultilib
+Use @var{dir} as a subdirectory of the directory containing
+target-specific C++ headers.
+
@item -isystem @var{dir}
@opindex isystem
Search @var{dir} for header files, after all directories specified by
@ifset cppmanual
@xref{System Headers}.
@end ifset
+If @var{dir} begins with @code{=}, then the @code{=} will be replaced
+by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
@item -iquote @var{dir}
@opindex iquote
@ifset cppmanual
@xref{Search Path}.
@end ifset
+If @var{dir} begins with @code{=}, then the @code{=} will be replaced
+by the sysroot prefix; see @option{--sysroot} and @option{-isysroot}.
+
+@item -fdirectives-only
+@opindex fdirectives-only
+When preprocessing, handle directives, but do not expand macros.
+
+The option's behavior depends on the @option{-E} and @option{-fpreprocessed}
+options.
+
+With @option{-E}, preprocessing is limited to the handling of directives
+such as @code{#define}, @code{#ifdef}, and @code{#error}. Other
+preprocessor operations, such as macro expansion and trigraph
+conversion are not performed. In addition, the @option{-dD} option is
+implicitly enabled.
+
+With @option{-fpreprocessed}, predefinition of command line and most
+builtin macros is disabled. Macros such as @code{__LINE__}, which are
+contextually dependent, are handled normally. This enables compilation of
+files previously preprocessed with @code{-E -fdirectives-only}.
+
+With both @option{-E} and @option{-fpreprocessed}, the rules for
+@option{-fpreprocessed} take precedence. This enables full preprocessing of
+files previously preprocessed with @code{-E -fdirectives-only}.
@item -fdollars-in-identifiers
@opindex fdollars-in-identifiers
@xref{Identifier characters}.
@end ifset
+@item -fextended-identifiers
+@opindex fextended-identifiers
+Accept universal character names in identifiers. This option is
+experimental; in a future version of GCC, it will be enabled by
+default for C99 and C++.
+
@item -fpreprocessed
@opindex fpreprocessed
Indicate to the preprocessor that the input file has already been
@item -fexec-charset=@var{charset}
@opindex fexec-charset
+@cindex character set, execution
Set the execution character set, used for string and character
constants. The default is UTF-8. @var{charset} can be any encoding
supported by the system's @code{iconv} library routine.
@item -fwide-exec-charset=@var{charset}
@opindex fwide-exec-charset
+@cindex character set, wide execution
Set the wide execution character set, used for wide string and
character constants. The default is UTF-32 or UTF-16, whichever
corresponds to the width of @code{wchar_t}. As with
@item -finput-charset=@var{charset}
@opindex finput-charset
+@cindex character set, input
Set the input character set, used for translation from the character
-set of the input file to the source character set used by GCC. If the
+set of the input file to the source character set used by GCC@. If the
locale does not specify, or GCC cannot get this information from the
-locale, the default is UTF-8. This can be overridden by either the locale
-or this command line option. Currently the command line option takes
-precedence if there's a conflict. @var{charset} can be any encoding
+locale, the default is UTF-8. This can be overridden by either the locale
+or this command line option. Currently the command line option takes
+precedence if there's a conflict. @var{charset} can be any encoding
supported by the system's @code{iconv} library routine.
@item -fworking-directory
@var{predicate}(@var{answer})}, which is still supported, because
it does not use shell special characters.
@ifset cppmanual
-@xref{Assertions}.
+@xref{Obsolete Features}.
@end ifset
@item -A -@var{predicate}=@var{answer}
@noindent
will show all the predefined macros.
+If you use @option{-dM} without the @option{-E} option, @option{-dM} is
+interpreted as a synonym for @option{-fdump-rtl-mach}.
+@xref{Debugging Options, , ,gcc}.
+
@item D
@opindex dD
Like @samp{M} except in two respects: it does @emph{not} include the
@opindex dI
Output @samp{#include} directives in addition to the result of
preprocessing.
+
+@item U
+@opindex dU
+Like @samp{D} except that only macros that are expanded, or whose
+definedness is tested in preprocessor directives, are output; the
+output is delayed until the use or test of the macro; and
+@samp{#undef} directives are also output for macros tested but
+undefined at the time.
@end table
@item -P
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