This option forces the preprocessor to handle files with
extensions as if macros have already been substituted.
This option gives you the opportunity to use a different preprocessor.
Generate your preprocessed code and then give the preprocessed code
to the compiler in the form of a
--preprocessed to inform the compiler that
the file has already been preprocessed.
This option only applies to macros. Trigraphs, line concatenation, comments and all other preprocessor items are preprocessed by the preprocessor in the normal way.
If you use
is treated as a
.c file. The preprocessor behaves
as if no prior preprocessing has occurred.