A plugin for camlp4 syntax extension (pa openin)
If you just want to use a syntax extension included in an installed package, see Using ocamlfind with ocamlbuild.
Suppose you have some Camlp4 OCaml syntax extension and that you want to compile them with Ocamlbuild.
Let start by adding an Ocamlbuild plugin (required to be in a file
myocamlbuild.ml at the root of your project).
(* Open the ocamlbuild world... *) open Ocamlbuild_plugin (* We work with commands so often... *) open Command (* This dispatch call allows to control the execution order of your directives. *) let () = dispatch begin function (* Add our rules after the standard ones. *) | After_rules -> (* Add pa_openin.cmo to the ocaml pre-processor when use_opening is set *) flag ["ocaml"; "pp"; "use_openin"] (A"pa_openin.cmo"); (* Running ocamldep on ocaml code that is tagged with use_openin will require the cmo. Note that you only need this declaration when the syntax extension is part of the sources to be compiled with ocamlbuild. *) dep ["ocaml"; "ocamldep"; "use_openin"] ["pa_openin.cmo"]; | _ -> () end
Then one can tag our files that use pa_openin:
$ cat _tags "bar.ml": camlp4o, use_openin <foo/*.ml> or <baz/**/*.ml>: camlp4r, use_openin "pa_openin.ml": use_camlp4, camlp4of
Now we can compile:
$ ocamlbuild bar.byte
This will build the
pa_openin.cmo and use it.