[CMake] CMake and Preprocessing

[Anastasia Shchupak]

Hello,
I'm porting multiplatform fortran project build system to CMake. Due to 
OpenMP code, I need to use FPP preprocessor always (before compiling by 
any compiler, because some fortran compilers use just CPP as 
preprocessor, that does not support OpenMP).
Is there a common solution using CMake to split preprocessing from 
compiling and set up a preprocessor that differs from that is 
incorporated into a compiler?
Thanks.
Anastasia.