If you think it is so trivial, then why hasn't it been done yet? Rust macros can't do all the same things that C #define macros can. You can't insert inline C

If you think it is so trivial, then why hasn't it been done yet? Rust macros can't do all the same things that C #define macros can. You can't insert inline C code into Rust code without some serious work. And the fact is, as you pointed out, regardless of in the future, right now it doesn't work, and those features are absolutely necessary for writing something like a Linux Kernel module.