I hope that's not all you think of tools like Futhark. As I mention in the article I spent a week trying to get c2nim to work (with 8 hour workdays). I'm not keen on using a C preprocessor to throw away information, I'm keen on using a C compiler to read C code instead of having to essentially implement one myself.
And I don't want to rewrite my C code to make it pass through c2nim, because that introduces human error risks. I want to wrap the actual C code I'm given. And I especially don't want to have to remember all the tweaks and modifications I did for whenever the API updates and I have to do it all over again on new C files. The case with macros not being a typed entity is unfortunate, and it's not something that a tool like c2nim would even solve, it would just try its best to make sense of it.