You do not usually preprocess Fortran source programs. If, however, you choose to preprocess your source programs, you must use the preprocessor fpp, or the preprocessing capability of a Fortran compiler. It is recommended to use fpp, which is the preprocessor supplied with the Intel® Fortran Compiler.
The compiler driver automatically invokes the preprocessor, depending on the source filename suffix and the option specified. For example, to preprocess a source file that contains standard Fortran preprocessor directives, then pass the preprocessed file to the compiler and linker, enter the following command:
IA-32 applications:
prompt>ifc source.fpp
Itanium(TM)-based applications:
prompt>efc source.fpp
Note
Using the preprocessor can make debugging difficult. To get around this,
you can save the preprocessed file (-P), and compile
it separately, so that the proper file information is recorded for the
debugger.
You can enable Preprocessor for any Fortran file by specifying the -fpp option. With -fpp, the compiler automatically invokes the fpp preprocessor to preprocess files with the .f, .for or .f90 suffix in the mode set by n:
n=0: disable CVF and #directives; equivalent to no fpp
n=1: enable CVF conditional compilation and #directives (-fpp1 is default)
n=2: enable only #directives
n=3: enable only CVF conditional compilation directives.
Note
Option -openmp automatically invokes the preprocessor.
Intel Fortran fpp conforms to cpp and accepts the cpp style directives. The cpp prohibits to use the string constant value in #if expression. So fpp won't support it either.