Ancient Fortran code readability is impacted by the restrictions on variable length that could lead to inscrutable variable and procedure names. The Fortran 2003 standard raised many of these limits to lengths that might only be a factor for auto-generated code with internally used very long names. If going beyond the usual name lengths, it’s a good idea to test across the compilers of interest (including compiler versions) to ensure that the required compiler vendors and versions can support the proposed name lengths.
CMake Fortran name length checks
CMake is a natural for this type of checking. We provide code examples verifying that compilers can support 63 character syntax elements (names for modules, submodules, variables), which is the maximum set by Fortran 2003 standard.