I just implemented a fast small compiler rcc to compete against tcc, and these glibc header quirks were simply fixed in the same way clang does it. By defining all gcc predefines and implementing all gcc extensions. Needed a day. And my headers are clean compared to glibc. The others in this league are slimcc, kefir and cproc. No other compilers can parse glibc headers. tcc has this special exception.

Back in my youth I implemented a C compiler that was almost impressive.

Dealing with the preprocessor (essentially a different, crippled language) was too much headache at the start so I just used `cpp`, and at the end, I was just too lazy to implement it, so continued using `cpp`.

(BTW: Anyone else here ever used the Cosmic C Compiler for Motorola microcontrollers? Amongst other idiosyncrasies, it had only one datatype - `byte` - and I had to implement macros to do 16-bit arithmetic operations. That project was easily the worst development experience of my life.)

If the codebase is small, and the dependencies are minimal, you might look into trying to integrate your rcc in "bootstrapping" flows, which currently often rely on tcc as a stepping stone towards gcc. And perhaps even being able to skip gcc 4.7 in favor of your compiler, if it's capable of, say, compiling a modern gcc to work even suboptimally.