open Ocamlbuild_plugin
open Command

let includes = Hashtbl.create 17
let register_include dir =
  if not (Hashtbl.mem includes dir) then begin
    Hashtbl.add includes dir ();
    dep [ "extension:ml" ]
      (List.map (fun s -> dir ^ "/" ^ s )
         (Array.to_list (Pathname.readdir dir)))
  end

let macro_flags = [
  "macro_include",
  (fun s -> register_include s; S [A"-ppopt"; A "-I"; A"-ppopt"; A s]);
  "macro_define", (fun s -> S [A"-ppopt"; A ("-D"^s)]);
]

let () = dispatch begin
  function
    | Before_rules ->
        List.iter (fun s ->
          List.iter (fun (fl, fu) ->
            pflag s fl fu) macro_flags
        )
          [["ocaml";"compile"];
           ["ocaml";"ocamldep"] ]
;
    | _ -> ()
end