Invalid preprocessing directive for #elseifdef in Xcode
Is #elseifdef directive not supported by Xcode?
It is not. Use this instead:
#elif defined(SOME_ANOTHER_TARGET_FLAG)
Its not supported as indicated by the error message. See 'the C preprocessor' - https://developer.apple.com/library/mac/#documentation/DeveloperTools/gcc-4.2.1/cpp/index.html#//apple_ref/doc/uid/TP40007092 (conditional compilation).