Ban empty record definitions (#384)

* Ban empty record declarations

* Use definition instead of declaration

* Fix the failing test

src/aeso_ast_infer_types.erl

@@ -1018,6 +1018,9 @@ check_typedef_sccs(Env, TypeMap, [{acyclic, Name} | SCCs], Acc) ->
             Env1 = bind_type(Name, Ann, {Xs, Def}, Env),
             case Def of
                 {alias_t, _}  -> check_typedef_sccs(Env1, TypeMap, SCCs, Acc1);
+                {record_t, []} ->
+                    type_error({empty_record_definition, Ann, Name}),
+                    check_typedef_sccs(Env1, TypeMap, SCCs, Acc1);
                 {record_t, Fields} ->
                     %% check_type to get qualified name
                     RecTy = check_type(Env1, app_t(Ann, D, Xs)),
@@ -3279,6 +3282,9 @@ mk_error({using_undefined_namespace_parts, Ann, Namespace, Parts}) ->
 mk_error({unknown_warning, Warning}) ->
     Msg = io_lib:format("Trying to report unknown warning: ~p", [Warning]),
     mk_t_err(pos(0, 0), Msg);
+mk_error({empty_record_definition, Ann, Name}) ->
+    Msg = io_lib:format("Empty record definitions are not allowed. Cannot define the record `~s`", [Name]),
+    mk_t_err(pos(Ann), Msg);
 mk_error(Err) ->
     Msg = io_lib:format("Unknown error: ~p", [Err]),
     mk_t_err(pos(0, 0), Msg).