#ifdef with gfortran 77

Question

I am using gfortran to compile FORTRAN 77 and would like to have DEBUG build options by using the preprocessor directive #ifdef. However, when I use them I get compile time warnings "Illegal preprocessor directive". Is it possible to have this functionality without deviating from the standard toolchain?

Answer 1

The c preprocessor can be used on the FORTRAN code for this purpose.

http://gcc.gnu.org/onlinedocs/gfortran/Preprocessing-Options.html