f95 supports two source file preprocessors, fpp and cpp. Either can be invoked by the compiler to expand source code “macros” and symbolic definitions prior to compilation. The compiler will use fpp by default; the -xpp=cpp option changes the default from fpp to cpp. (See also the discussion of the -Dname option).
fpp is a Fortran-specific source preprocessor. See the fpp(1) man page and the fpp README for details. It is invoked by default on files with a .F, .F90, F95, or .F03 extension.
The source code for fpp is available from the Netlib web site at
See cpp(1) for information on the standard Unix C language preprocessor. Use of fpp over cpp is recommended on Fortran source files.