Extensible Interface Files

GHC tooling in general knows about two build artifacts when compiling haskell code this is object code contained in the .o files, as well as meta information contained in the .hi files. The information that’s contained in .hi files is primarily used to inlines code that was marked as INLINABLE, and for type information about exported symbols.

Extensible Interface Files allows us to embed arbitrary extra data encoded by a key into .hi files. We want this for plutus, where the plutus compiler needs the core (one of GHC internal representations) representation of the haskell functions to properly translate a plutus program. This is currently done by forcing GHC to include the represenations using a few specific compilier flags. Extensible Interface Files provides this with a solid foundation, and we are currently in the process of moving the plutus compiler to use the Extensible Interface Files.