Skip abstract forwarding stubs

Change-Id: If0c0967e55038d330fef48d97bc96a92b0f4b506
Reviewed-on: https://dart-review.googlesource.com/49860
Commit-Queue: Johnni Winther <[email protected]>
Reviewed-by: Sigmund Cherem <[email protected]>

pkg/compiler/lib/src/kernel/env.dart

@@ -317,6 +317,21 @@ class ClassEnvImpl implements ClassEnv {
 
     void addProcedures(ir.Class c, {bool includeStatic}) {
       for (ir.Procedure member in c.procedures) {
+        if (member.isForwardingStub && member.isAbstract) {
+          // Skip abstract forwarding stubs. These are never emitted but they
+          // might shadow the inclusion of a mixed in method in code like:
+          //
+          //     class Super {}
+          //     class Mixin<T> {
+          //       void method(T t) {}
+          //     }
+          //     class Class extends Super with Mixin<int> {}
+          //     main() => new Class().method();
+          //
+          // Here a stub is created for `Super&Mixin.method` hiding that
+          // `Mixin.method` is inherited by `Class`.
+          continue;
+        }
         if (!includeStatic && member.isStatic) continue;
         var name = member.name.name;
         assert(!name.contains('#'));

pkg/compiler/lib/src/universe/function_set.dart

@@ -242,6 +242,19 @@ class FunctionSetNode {
         : const EmptyFunctionSetQuery();
     return result;
   }
+
+  String toString() {
+    StringBuffer sb = new StringBuffer();
+    sb.write('FunctionSetNode(');
+    String comma = '';
+    cache.forEach((mask, query) {
+      sb.write(comma);
+      sb.write('$mask=$query');
+      comma = ',';
+    });
+    sb.write(')');
+    return sb.toString();
+  }
 }
 
 /// A set of functions that are the potential targets of all call sites sharing
@@ -265,6 +278,8 @@ class EmptyFunctionSetQuery implements FunctionSetQuery {
 
   @override
   Iterable<MemberEntity> get functions => const <MemberEntity>[];
+
+  String toString() => '<empty>';
 }
 
 class FullFunctionSetQuery implements FunctionSetQuery {
@@ -296,4 +311,6 @@ class FullFunctionSetQuery implements FunctionSetQuery {
         }),
         closedWorld);
   }
+
+  String toString() => '$_mask:$functions';
 }

tests/compiler/dart2js/model/forwarding_stub_test.dart

@@ -0,0 +1,44 @@
+// Copyright (c) 2018, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:async_helper/async_helper.dart';
+import 'package:compiler/src/commandline_options.dart';
+import 'package:compiler/src/common_elements.dart';
+import 'package:compiler/src/compiler.dart';
+import 'package:compiler/src/elements/entities.dart';
+import 'package:compiler/src/world.dart';
+import 'package:expect/expect.dart';
+import '../memory_compiler.dart';
+
+const String source = '''
+
+class Mixin<T> {
+  void method(T t) {}
+}
+class Super {}
+class Class extends Super with Mixin<int> {}
+
+main() {
+  new Class().method(0);
+}
+''';
+
+main() {
+  asyncTest(() async {
+    CompilationResult result = await (runCompiler(
+        memorySourceFiles: {'main.dart': source}, options: [Flags.strongMode]));
+    Expect.isTrue(result.isSuccess);
+    Compiler compiler = result.compiler;
+    ClosedWorld closedWorld = compiler.backendClosedWorldForTesting;
+    ElementEnvironment elementEnvironment = closedWorld.elementEnvironment;
+    ClassEntity cls =
+        elementEnvironment.lookupClass(elementEnvironment.mainLibrary, 'Class');
+    ClassEntity mixin =
+        elementEnvironment.lookupClass(elementEnvironment.mainLibrary, 'Mixin');
+    FunctionEntity method = elementEnvironment.lookupClassMember(cls, 'method');
+    Expect.isNotNull(method);
+    Expect.equals(mixin, method.enclosingClass);
+    Expect.isFalse(method.isAbstract);
+  });
+}

tests/corelib_2/corelib_2.status

@@ -234,7 +234,6 @@ list_unmodifiable_test: RuntimeError
 main_test: RuntimeError
 nan_infinity_test/01: RuntimeError
 regexp/pcre_test: RuntimeError
-string_fromcharcodes_test: RuntimeError
 string_split_test/checkedstore: RuntimeError # Issue 30548: does not check stores into List<String>
 symbol_reserved_word_test/03: RuntimeError # Issue 19972, new Symbol('void') should be allowed.
 uri_base_test: RuntimeError
@@ -266,7 +265,6 @@ main_test: RuntimeError
 nan_infinity_test/01: RuntimeError
 nsm_invocation_test: RuntimeError # Symbols don't match due to minifiaction.
 regexp/pcre_test: RuntimeError
-string_fromcharcodes_test: RuntimeError
 string_split_test/checkedstore: RuntimeError # Issue 30548: does not check stores into List<String>
 symbol_operator_test/03: RuntimeError
 symbol_operator_test/none: RuntimeError
@@ -275,9 +273,6 @@ uri_base_test: RuntimeError
 uri_parameters_all_test: RuntimeError
 uri_test: RuntimeError
 
-[ $compiler == dart2js && $fasta && $strong ]
-shuffle_test: RuntimeError
-
 [ $compiler == dart2js && $fasta && !$strong ]
 *: SkipByDesign
 

tests/language_2/language_2_dart2js.status

@@ -546,7 +546,6 @@ covariance_field_test/02: RuntimeError
 covariance_field_test/03: RuntimeError
 covariance_field_test/04: RuntimeError
 covariance_field_test/05: RuntimeError
-recursive_mixin_test: RuntimeError # no check without --checked
 
 [ $compiler == dart2js && !$checked && !$enable_asserts ]
 assertion_test: RuntimeError, OK
@@ -2324,8 +2323,6 @@ wrong_number_type_arguments_test/none: Pass
 [ $compiler == dart2js && $fasta && $strong ]
 const_constructor3_test/04: MissingCompileTimeError # OK - Subtype check uses JS number semantics.
 ct_const_test: RuntimeError
-mixin_type_parameter5_test: RuntimeError
-mixin_type_parameter6_test: RuntimeError
 
 [ $compiler == dart2js && $fasta && !$strong ]
 *: SkipByDesign