[interpol_p]

While it's probably possible, I can't imagine it would be an simple task to generalise that level of code analysis across languages.

If you look at Xcode, it saw a significant improvement when it started using clang to build its indexes. That is purely a C, C++ and Objective-C front end to LLVM.

Xcode basically requires a significant portion of a compiler to provide a decent coding environment.

What you are suggesting is almost to create a compiler "protocol" that can handle all languages. I am not sure how much value you would get from such a protocol.