Check if a language can be enabled
where <lang> is a language that may be passed to enable_language() such as “Fortran”. If CMAKE_<lang>_COMPILER is already defined the check does nothing. Otherwise it tries enabling the language in a test project. The result is cached in CMAKE_<lang>_COMPILER as the compiler that was found, or NOTFOUND if the language cannot be enabled.
check_language(Fortran) if(CMAKE_Fortran_COMPILER) enable_language(Fortran) else() message(STATUS "No Fortran support") endif()