Fix static dependencies

Signed-off-by: Rudi Grinberg <rudi.grinberg@gmail.com>

src/super_context.ml

@@ -845,24 +845,11 @@ module Action = struct
       match targets_written_by_user with
       | Infer -> Loc.fail loc "You cannot use %s with inferred rules." var
       | Alias -> Loc.fail loc "You cannot use %s in aliases." var
-      | Static l -> Some (Value.L.paths l)
+      | Static l -> Some (Value.L.dirs l) (* XXX hack to signal no dep *)
     in
-    let expand var syntax_version =
+    let expand_form s var syntax_version =
       let loc = String_with_vars.Var.loc var in
       let key = String_with_vars.Var.full_name var in
-      match String_with_vars.Var.destruct var with
-      | Single var_name ->
-        begin match expand_var_no_root sctx ~syntax_version ~var with
-        | None -> String.Map.find extra_vars key
-        | Some Targets -> targets loc var_name
-        | Some v ->
-          let exp = Var.Kind.to_value_no_deps_or_targets ~scope v in
-          Option.iter exp ~f:(fun v ->
-            acc.sdeps <- Path.Set.union
-                           (Path.Set.of_list (Value.L.deps_only v)) acc.sdeps);
-          exp
-        end
-      | Pair (_, s)->
       begin match expand_form sctx ~syntax_version ~var with
       | Some Var.Form.Exe -> Some (path_exp (map_exe (Path.relative dir s)))
       | Some Dep -> Some (path_exp (Path.relative dir s))
@@ -953,6 +940,25 @@ module Action = struct
         String_with_vars.Var.fail var ~f:(sprintf "Unknown form: %s")
       end
     in
+    let expand var syntax_version =
+      let loc = String_with_vars.Var.loc var in
+      let key = String_with_vars.Var.full_name var in
+      let res =
+        match String_with_vars.Var.destruct var with
+        | Single var_name ->
+          begin match expand_var_no_root sctx ~syntax_version ~var with
+          | None -> String.Map.find extra_vars key
+          | Some Targets -> targets loc var_name
+          | Some v -> Var.Kind.to_value_no_deps_or_targets v ~scope
+          end
+        | Pair (_, s) -> expand_form s var syntax_version
+      in
+      Option.iter res ~f:(fun v ->
+        acc.sdeps <- Path.Set.union
+                       (Path.Set.of_list (Value.L.deps_only v)) acc.sdeps
+      );
+      res
+    in
     let t = U.partial_expand t ~dir ~map_exe ~f:expand in
     (t, acc)
 

src/value.ml

@@ -35,4 +35,6 @@ module L = struct
   let strings = List.map ~f:(fun x -> String x)
 
   let paths = List.map ~f:(fun x -> Path x)
+
+  let dirs = List.map ~f:(fun x -> Dir x)
 end

src/value.mli

@@ -16,6 +16,8 @@ module L : sig
 
   val deps_only : t list -> Path.t list
 
+  val dirs : Path.t list -> t list
+
   val concat : t list -> dir:Path.t -> string
 
   val to_strings : t list -> dir:Path.t -> string list