Is there any similar project like this where LLVM IR is used? I’ll start building a language just for fun during weekends and I plan to use LLVM but it is rather hard to understand clang on limited time, so a smaller scale project would be awesome.
When it comes to both parsing and emitting IR, keep it simple (stupid!) - the difficult bit (on a day to day basis) with the compiler is almost always the language semantics, the backend is more theory-dense but to just implement a language you can use LLVM as a black-box.
If you minimise mutable state and utilise lowering (you can implement foreach by lowering the AST to a for loop, for example) your compiler will be much easier to debug.