Since Objective-C is a true superset of C (unlike C++) and there's also Objective-C++, you can just tell the compiler to compile all .c/.cpp as if they were .m/

Since Objective-C is a true superset of C (unlike C++) and there's also Objective-C++, you can just tell the compiler to compile all .c/.cpp as if they were .m/.mm. That is, if you can figure out how to coax your build system to pass the right flags.