Compute NativeBasicData for KernelWorldBuilder

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

+// Copyright (c) 2017, 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.
+
+// TODO(johnniwinther): Make this a separate library.
+part of dart2js.kernel.world_builder;
+
+class KernelAnnotationProcessor implements AnnotationProcessor {
+  final KernelWorldBuilder worldBuilder;
+
+  KernelAnnotationProcessor(this.worldBuilder);
+
+  void extractNativeAnnotations(
+      LibraryEntity library, NativeBasicDataBuilder nativeBasicDataBuilder) {
+    ElementEnvironment elementEnvironment = worldBuilder.elementEnvironment;
+    CommonElements commonElements = worldBuilder.commonElements;
+
+    elementEnvironment.forEachClass(library, (ClassEntity cls) {
+      String annotationName;
+      // TODO(johnniwinther): Make [_getClassMetadata] public and at test to
+      // guard against misuse.
+      for (ConstantExpression annotation
+          in worldBuilder._getClassMetadata(cls)) {
+        ConstantValue value =
+            worldBuilder.constantEnvironment.getConstantValue(annotation);
+        String name = readAnnotationName(
+            cls, value, commonElements.nativeAnnotationClass);
+        if (annotationName == null) {
+          annotationName = name;
+        } else if (name != null) {
+          throw new SpannableAssertionFailure(
+              cls, 'Too many name annotations.');
+        }
+      }
+      if (annotationName != null) {
+        nativeBasicDataBuilder.setNativeClassTagInfo(cls, annotationName);
+      }
+    });
+  }
+
+  void extractJsInteropAnnotations(
+      LibraryEntity library, NativeBasicDataBuilder nativeBasicDataBuilder) {
+    throw new UnimplementedError(
+        'KernelAnnotationProcessor.extractJsInteropAnnotations');
+  }
+}