1. A method for conditionally pre-processing a single code set to determine platform-specific portions of the code set to execute in a corresponding platform, the method comprising: determining, in a mainframe computing system, a host platform comprising the platform in which an application is to be executed; pre-processing a code set comprising the application to identify a plurality of platform-compatible portions of the code set which are compatible with execution on the host platform; and compiling the platform-compatible portions of the code set, wherein the code set comprises a single code set programmed under COBOL programming language, further wherein, the method is performed in a mainframe computing system operating a plurality of platforms in a plurality of logical partitions.