dart2js-kernel: handle top-level / static unresolved methods / getters / setters

pkg/compiler/lib/src/js_backend/backend_helpers.dart

Index: pkg/compiler/lib/src/js_backend/backend_helpers.dart
diff --git a/pkg/compiler/lib/src/js_backend/backend_helpers.dart b/pkg/compiler/lib/src/js_backend/backend_helpers.dart
index 3d7944e4b9a171e0cc97a200a7719c8099a9cf10..a4f814f654ef20ed5a8d9b2f40ae81a3b63677fd 100644
--- a/pkg/compiler/lib/src/js_backend/backend_helpers.dart
+++ b/pkg/compiler/lib/src/js_backend/backend_helpers.dart
@@ -638,17 +638,26 @@ class BackendHelpers {
     return _findHelper('throwNoSuchMethod');
   }
 
-  Element get genericNoSuchMethod =>
-      _genericNoSuchMethod ??= findCoreHelper('_genericNoSuchMethod');
-  MethodElement _genericNoSuchMethod;
-
-  Element get unresolvedConstructorError => _unresolvedConstructorError ??=
-      findCoreHelper('_unresolvedConstructorError');
-  MethodElement _unresolvedConstructorError;
-
-  Element get malformedTypeError =>
-      _malformedTypeError ??= findCoreHelper('_malformedTypeError');
-  MethodElement _malformedTypeError;
+  Element get malformedTypeError => _cachedCoreHelper('_malformedTypeError');
+  Element get genericNoSuchMethod => _cachedCoreHelper('_genericNoSuchMethod');
+  Element get unresolvedConstructorError =>
+      _cachedCoreHelper('_unresolvedConstructorError');
+  Element get unresolvedStaticGetterError =>
+      _cachedCoreHelper('_unresolvedStaticGetterError');
+  Element get unresolvedStaticSetterError =>
+      _cachedCoreHelper('_unresolvedStaticSetterError');
+  Element get unresolvedStaticMethodError =>
+      _cachedCoreHelper('_unresolvedStaticMethodError');
+  Element get unresolvedTopLevelGetterError =>
+      _cachedCoreHelper('_unresolvedTopLevelGetterError');
+  Element get unresolvedTopLevelSetterError =>
+      _cachedCoreHelper('_unresolvedTopLevelSetterError');
+  Element get unresolvedTopLevelMethodError =>
+      _cachedCoreHelper('_unresolvedTopLevelMethodError');
+
+  Map<String, Element> _cachedCoreHelpers = <String, Element>{};
+  Element _cachedCoreHelper(String name) =>
+      _cachedCoreHelpers[name] ??= findCoreHelper(name);

[Siggi Cherem (dart-lang), 2017/01/11 19:08:03]

Im ok with either, but any reason to prefer this or putIfAbsent?

[sra1, 2017/01/11 19:14:39]

putIfAbsent requires a closure argument (hence allocation) for each lookup.

 
   Element get createRuntimeType {
     return _findHelper('createRuntimeType');