Using jbuilder to run protoc

I’m starting on a new Ocaml project, and I wanted to use protobuffers as my serialization format. ocaml-protoc seems like a fairly well-adopted implementation of a protobuf compiler for ocaml, but figuring out how to get it to run automatically as part of a jbuilder build was not particularly well documented.

Jbuilder behaves somewhat like make (and ironically uses a lisp-ish configuration language). Given this, I made a rule whose output would be the generated .ml and .mli files, and required those resulting files to be installed (causing them to get generated at build time).

I added these two stanzas to my jbuild file:

(rule
 ((targets (messages_types.mli messages_types.ml
            messages_pb.mli messages_pb.ml))
  (deps (messages.proto))
  (action
       (run ocaml-protoc -binary -ml_out ./ ${<}))))

(install
  ((section etc)
   (files (messages_*.mli messages_*.ml))))

I’m still getting used to jbuilder, so I’m sure there’s less repetitive ways of getting this accomplished. If you have any suggestions, let me know!