Better signature for Artifacts.file_of_lib (#418)

src/artifacts.ml

@@ -100,12 +100,3 @@ let file_of_lib t ~from ~lib ~file =
                     : Findlib.package);
             assert false
         }
-
-let file_of_lib t ~loc ~from name =
-  let lib, file =
-    match String.lsplit2 name ~on:':' with
-    | None ->
-      Loc.fail loc "invalid ${lib:...} form: %s" name
-    | Some x -> x
-  in
-  (lib, file_of_lib t ~from ~lib ~file)

src/artifacts.mli

@@ -18,14 +18,11 @@ val binary
   -> string
   -> Action.Prog.t
 
-(** [file_of_lib t ~from name] a named artifact that is looked up in the given library.
-
-    [name] is expected to be of the form "<lib>:<file>". Raises immediately if it is not
-    the case. Returns "<lib>" as well as the resolved artifact.
-*)
+(** [file_of_lib t ~from ~lib ~file] returns the path to a file in the directory of the
+    given library. *)
 val file_of_lib
   :  t
-  -> loc:Loc.t
   -> from:Path.t
-  -> string
-  -> string * (Path.t, fail) result
+  -> lib:string
+  -> file:string
+  -> (Path.t, fail) result

src/js_of_ocaml_rules.ml

@@ -18,11 +18,10 @@ let in_build_dir ~ctx =
   List.fold_left ~init ~f:Path.relative
 
 let runtime_file ~sctx ~dir fname =
-  let _lib, file =
-    Artifacts.file_of_lib (SC.artifacts sctx) ~loc:Loc.none ~from:dir
-      (sprintf "js_of_ocaml-compiler:%s" fname)
-  in
-  match file with
+  match
+    Artifacts.file_of_lib (SC.artifacts sctx) ~from:dir
+      ~lib:"js_of_ocaml-compiler" ~file:fname
+  with
   | Error _ ->
     Arg_spec.Dyn (fun _ ->
       Utils.library_not_found ~context:(SC.context sctx).name ~hint:install_jsoo_hint

src/super_context.ml

@@ -534,6 +534,12 @@ module Action = struct
           Path.append host.context.build_dir exe
         | _ -> exe
 
+  let parse_lib_file ~loc s =
+    match String.lsplit2 s ~on:':' with
+    | None ->
+      Loc.fail loc "invalid ${lib:...} form: %s" s
+    | Some x -> x
+
   let expand_step1 sctx ~dir ~dep_kind ~scope ~targets_written_by_user ~map_exe t =
     let acc =
       { failures  = []
@@ -566,19 +572,23 @@ module Action = struct
         (* "findlib" for compatibility with Jane Street packages which are not yet updated
            to convert "findlib" to "lib" *)
         | Some (("lib"|"findlib"), s) -> begin
-            let lib_dep, res =
-              Artifacts.file_of_lib (artifacts sctx) ~loc ~from:dir s in
+            let lib_dep, file = parse_lib_file ~loc s in
             add_lib_dep acc lib_dep dep_kind;
-            match res with
+            match
+              Artifacts.file_of_lib (artifacts sctx) ~from:dir
+                ~lib:lib_dep ~file
+            with
             | Ok path -> static_dep_exp acc path
             | Error fail -> add_fail acc fail
           end
         | Some ("libexec" , s) -> begin
             let sctx = host_sctx sctx in
-            let lib_dep, res =
-              Artifacts.file_of_lib (artifacts sctx) ~loc ~from:dir s in
+            let lib_dep, file = parse_lib_file ~loc s in
             add_lib_dep acc lib_dep dep_kind;
-            match res with
+            match
+              Artifacts.file_of_lib (artifacts sctx) ~from:dir
+                ~lib:lib_dep ~file
+            with
             | Error fail -> add_fail acc fail
             | Ok path ->
               if not Sys.win32 || Filename.extension s = ".exe" then begin