84 lines
3.2 KiB
Plaintext
84 lines
3.2 KiB
Plaintext
@c Copyright (c) 1999, 2000, 2001, 2002
|
|
@c Free Software Foundation, Inc.
|
|
@c This is part of the CPP and GCC manuals.
|
|
@c For copying conditions, see the file gcc.texi.
|
|
|
|
@c ---------------------------------------------------------------------
|
|
@c Environment variables affecting the preprocessor
|
|
@c ---------------------------------------------------------------------
|
|
|
|
@c If this file is included with the flag ``cppmanual'' set, it is
|
|
@c formatted for inclusion in the CPP manual; otherwise the main GCC manual.
|
|
|
|
@vtable @env
|
|
@item CPATH
|
|
@itemx C_INCLUDE_PATH
|
|
@itemx CPLUS_INCLUDE_PATH
|
|
@itemx OBJC_INCLUDE_PATH
|
|
@c Commented out until ObjC++ is part of GCC:
|
|
@c @itemx OBJCPLUS_INCLUDE_PATH
|
|
Each variable's value is a list of directories separated by a special
|
|
character, much like @env{PATH}, in which to look for header files.
|
|
The special character, @code{PATH_SEPARATOR}, is target-dependent and
|
|
determined at GCC build time. For Windows-based targets it is a
|
|
semicolon, and for almost all other targets it is a colon.
|
|
|
|
@env{CPATH} specifies a list of directories to be searched as if
|
|
specified with @option{-I}, but after any paths given with @option{-I}
|
|
options on the command line. This environment variable is used
|
|
regardless of which language is being preprocessed.
|
|
|
|
The remaining environment variables apply only when preprocessing the
|
|
particular language indicated. Each specifies a list of directories
|
|
to be searched as if specified with @option{-isystem}, but after any
|
|
paths given with @option{-isystem} options on the command line.
|
|
|
|
In all these variables, an empty element instructs the compiler to
|
|
search its current working directory. Empty elements can appear at the
|
|
beginning or end of a path. For instance, if the value of
|
|
@env{CPATH} is @code{:/special/include}, that has the same
|
|
effect as @samp{@w{-I. -I/special/include}}.
|
|
|
|
@c man end
|
|
@ifset cppmanual
|
|
See also @ref{Search Path}.
|
|
@end ifset
|
|
@c man begin ENVIRONMENT
|
|
|
|
@item DEPENDENCIES_OUTPUT
|
|
@cindex dependencies for make as output
|
|
If this variable is set, its value specifies how to output
|
|
dependencies for Make based on the non-system header files processed
|
|
by the compiler. System header files are ignored in the dependency
|
|
output.
|
|
|
|
The value of @env{DEPENDENCIES_OUTPUT} can be just a file name, in
|
|
which case the Make rules are written to that file, guessing the target
|
|
name from the source file name. Or the value can have the form
|
|
@samp{@var{file} @var{target}}, in which case the rules are written to
|
|
file @var{file} using @var{target} as the target name.
|
|
|
|
In other words, this environment variable is equivalent to combining
|
|
the options @option{-MM} and @option{-MF}
|
|
@ifset cppmanual
|
|
(@pxref{Invocation}),
|
|
@end ifset
|
|
@ifclear cppmanual
|
|
(@pxref{Preprocessor Options}),
|
|
@end ifclear
|
|
with an optional @option{-MT} switch too.
|
|
|
|
@item SUNPRO_DEPENDENCIES
|
|
@cindex dependencies for make as output
|
|
This variable is the same as @env{DEPENDENCIES_OUTPUT} (see above),
|
|
except that system header files are not ignored, so it implies
|
|
@option{-M} rather than @option{-MM}. However, the dependence on the
|
|
main input file is omitted.
|
|
@ifset cppmanual
|
|
@xref{Invocation}.
|
|
@end ifset
|
|
@ifclear cppmanual
|
|
@xref{Preprocessor Options}.
|
|
@end ifclear
|
|
@end vtable
|