I am working on an Intel Visual Fortran solution provided to me by a third party. I am trying to gain a deeper understanding of how this solution is built. The .FOR files included within this solution, for several of them contain preprocessor directives such as #ifdef and #else. I understand vaguely what these preprocessors do (test for definition of a macro). I also understand that the tokens used must refer to a pre-existing macro generated using the directive #define. I cannot find this macro defined anywhere in my solution.
I also know that the definitions are somehow linked to the "Debug" and "Release" configuration set-up in Visual Studio, since the Macro names are such things as "Internal Debug" and "Internal Release".
Where does visual fortran define its preprocessing macros? If it uses a provided construct within Microsoft Visual Studio, where is this construct and how can I manipulate it?