refactor(melange): make modes field an Ordered_set_lang instance

Signed-off-by: Antonio Nuno Monteiro <[email protected]>

src/dune_rules/dune_file.ml

@@ -467,6 +467,15 @@ module Mode_conf = struct
 
     let to_dyn t = Dyn.variant (to_string t) []
 
+    let equal x y =
+      match (x, y) with
+      | Ocaml o1, Ocaml o2 -> (
+        match compare o1 o2 with
+        | Eq -> true
+        | _ -> false)
+      | Ocaml _, _ | _, Ocaml _ -> false
+      | Melange, Melange -> true
+
     module Map = struct
       type nonrec 'a t =
         { ocaml : 'a Map.t
@@ -609,9 +618,7 @@ module Library = struct
          Ordered_set_lang.Unexpanded.field "c_library_flags"
        and+ virtual_deps =
          field "virtual_deps" (repeat (located Lib_name.decode)) ~default:[]
-       and+ modes =
-         field "modes" Mode_conf.Lib.Set.decode
-           ~default:(Mode_conf.Lib.Set.default stanza_loc)
+       and+ modes = field_o "modes" Ordered_set_lang.decode
        and+ kind = field "kind" Lib_kind.decode ~default:Lib_kind.Normal
        and+ optional = field_b "optional"
        and+ no_dynlink = field_b "no_dynlink"
@@ -712,6 +719,25 @@ module Library = struct
                  (Package.Name.to_string (Package.name public.package))
              ]
        in
+       let modes =
+         match modes with
+         | None -> Mode_conf.Lib.Set.default stanza_loc
+         | Some modes ->
+           let modes =
+             Ordered_set_lang.eval modes
+               ~parse:(fun ~loc s ->
+                 let mode =
+                   Dune_lang.Decoder.parse Mode_conf.Lib.decode
+                     (Dune_project.parsing_context project)
+                     (Atom (loc, Dune_lang.Atom.of_string s))
+                 in
+                 (mode, Mode_conf.Kind.Requested loc))
+               ~eq:(fun (a, _) (b, _) -> Mode_conf.Lib.equal a b)
+               ~standard:[ (Ocaml Best, Mode_conf.Kind.Requested stanza_loc) ]
+           in
+           let modes = Mode_conf.Lib.Set.of_list modes in
+           modes
+       in
        Option.both virtual_modules implements
        |> Option.iter ~f:(fun (virtual_modules, (_, impl)) ->
               User_error.raise

test/blackbox-tests/test-cases/melange/promote-with-lib.t

@@ -8,7 +8,7 @@ Test melange.emit promotion
   $ mkdir lib
   $ cat > lib/dune <<EOF
   > (library
-  >  (modes melange)
+  >  (modes :standard melange)
   >  (name mylib))
   > EOF
 
@@ -34,6 +34,11 @@ Test melange.emit promotion
 
   $ dune build @dist
 
+Library has `(modes :standard)` so it also builds for bytecode / native
+
+  $ dune build lib/.mylib.objs/byte/mylib.cmo
+  $ dune build lib/.mylib.objs/native/mylib.cmx
+
 Targets are promoted to the source tree
 
   $ ls ./dist