You shouldn't take the `GCC_` as meaning "only affects GCC`: that's an Xcode Build Setting, and it has nothing to do with the actual compiler used. For what's worth, Apple could have named it `FROGBLAST_DEBUGGING_SYMBOLS` and that would have been the same. But yeah, I think Xcode is stuck using those `GCC_` names because of backward-compatibility and Xcode will do whatever is needed (hopefully ;-)) so that the specific compiler you're using gets it's needed flags