Index: pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/types.dart |
diff --git a/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/types.dart b/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/types.dart |
index abc476d54c70615a597a402851cb59b79606b444..e64daf7484bd035645af85ecc71bb9ccf3341383 100644 |
--- a/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/types.dart |
+++ b/pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/types.dart |
@@ -656,15 +656,9 @@ isFunctionSubtype(ft1, ft2, isCovariant) => JS( |
// Check return type last, so that arity mismatched functions can be |
// definitively rejected. |
- // We allow any type to subtype a void return type, but not vice versa |
- if (ret2 === $_void) return true; |
- // Dart allows void functions to subtype dynamic functions, but not |
- // other functions. |
- // TODO(jmesserly): this check does not match our compile time subtype |
- // implementation. Reconcile. |
- if (ret1 === $_void) { |
- return ret2 === $dynamic || ret2 === $FutureOr; |
- } |
+ // For `void` we will give the same answer as the VM, so don't return null. |
+ if (ret1 === $_void) return $_isTop(ret2); |
+ |
if (!$_isSubtype(ret1, ret2, $isCovariant)) return null; |
return true; |
})()'''); |
@@ -698,13 +692,14 @@ _subtypeMemo(f) => JS( |
final isSubtype = JS( |
'', '$_subtypeMemo((t1, t2) => (t1 === t2) || $_isSubtype(t1, t2, true))'); |
-_isBottom(type) => JS('bool', '# == #', type, bottom); |
+_isBottom(type) => JS('bool', '# == # || # == #', type, bottom, type, Null); |
_isTop(type) { |
if (JS('bool', '# === #', getGenericClass(type), getGenericClass(FutureOr))) { |
return _isTop(JS('', '#[0]', getGenericArgs(type))); |
} |
- return JS('bool', '# == # || # == #', type, Object, type, dynamic); |
+ return JS('bool', '# == # || # == # || # == #', |
+ type, Object, type, dynamic, type, _void); |
} |
_isSubtype(t1, t2, isCovariant) => JS( |