[interpreter] Remove unused NullPat

Author: rossberg

interpreter/script/js.ml

@@ -435,7 +435,6 @@ let type_of_vec_pat = function
 let type_of_ref_pat = function
   | RefPat ref -> type_of_ref ref.it
   | RefTypePat ht -> (NoNull, ht)
-  | NullPat -> (Null, BotHT)
 
 let rec type_of_result res =
   match res.it with
@@ -555,10 +554,6 @@ let assert_return ress ts at =
       [ RefTest (NoNull, t) @@ at;
         Test (I32 I32Op.Eqz) @@ at;
         BrIf (0l @@ at) @@ at ]
-    | RefResult NullPat ->
-      [ RefIsNull @@ at;
-        Test (I32 I32Op.Eqz) @@ at;
-        BrIf (0l @@ at) @@ at ]
     | EitherResult ress ->
       let idx = Lib.List32.length !locals in
       locals := !locals @ [Local t @@ res.at];
@@ -733,7 +728,6 @@ let of_vec_pat = function
 let of_ref_pat = function
   | RefPat r -> of_ref r.it
   | RefTypePat t -> "\"ref." ^ string_of_heaptype t ^ "\""
-  | NullPat -> "\"ref.null\""
 
 let rec of_result res =
   match res.it with

interpreter/script/runner.ml

@@ -265,7 +265,6 @@ let string_of_ref_pat (p : ref_pat) =
   match p with
   | RefPat r -> Value.string_of_ref r.it
   | RefTypePat t -> Types.string_of_heaptype t
-  | NullPat -> "null"
 
 let rec string_of_result r =
   match r.it with
@@ -286,7 +285,6 @@ let rec type_of_result r =
   | VecResult (VecPat v) -> Types.VecT (Value.type_of_vec v)
   | RefResult (RefPat r) -> Types.RefT (Value.type_of_ref r.it)
   | RefResult (RefTypePat t) -> Types.(RefT (NoNull, t))  (* assume closed *)
-  | RefResult (NullPat) -> Types.(RefT (Null, ExternHT))
   | EitherResult rs ->
     let ts = List.map type_of_result rs in
     List.fold_left (fun t1 t2 ->
@@ -463,7 +461,6 @@ let assert_ref_pat r p =
   | RefTypePat Types.FuncHT, Instance.FuncRef _
   | RefTypePat Types.ExnHT, Exn.ExnRef _
   | RefTypePat Types.ExternHT, _ -> true
-  | NullPat, Value.NullRef -> true
   | _ -> false
 
 let rec assert_result v r =

interpreter/script/script.ml

@@ -30,7 +30,6 @@ type vec_pat =
 type ref_pat =
   | RefPat of ref_
   | RefTypePat of Types.heaptype
-  | NullPat
 
 type result = result' Source.phrase
 and result' =

interpreter/text/arrange.ml

@@ -851,7 +851,6 @@ let vec_pat mode = function
 let ref_pat = function
   | RefPat r -> ref_ r.it
   | RefTypePat t -> Node ("ref." ^ heaptype t, [])
-  | NullPat -> Node ("ref.null", [])
 
 let rec result mode res =
   match res.it with