Hi Shaku,
PolySpace Code Prover generally starts the analysis from an entry point, usually the main function or a function specified as entry point. When you mark a file as ‘not called by generated main’, you are indicating that this file is not part of the execution path from the main function.
Hence, if the file marked as ‘not called by generated main’ is indeed not invoked from the path starting from main function, you will see no change in the analysis results.
As a best practice, only use this option when you are clear that your code is unreachable from the main or you want to focus the analysis on specific parts of the module.
PolySpace Code Prover provides various such analysis options, you can use the link below to read more about them:
Hope this helps!