A compiler in Haskell for (a subset of) C

Because writing a compiler in C is just boring

(TODO: Turn this into a nice blog post)

Parsing (the nice part)

Let's talk about the good parts first. The parser is fairly straight-forward, using megaparsec, working with the C specification documents is bothersome though, so please don't expect that it works on more complicated files. Also, there's no preprocessor.

Semantic Analysis (the cool part)

For the type checking part we really wanted to be able to annotate our AST at specific places with type annotations. We had no idea how to achieve that in a 'nice' way, but #haskell to the rescue! Someone pointed us to the "Trees That Grow" paper, and it described exactly the problem we had encountered too.

So, a e :: Expr SynPhase (an expression after parsing) contains a SourcePos whereas a e :: Expr SemPhase, contains a Type. Nice!

Code Generation (the ugly part)

We used llvm-hs-pure to generate some LLVM code. The whole Codegen module is more of a last-minute result and utterly incorrect.