VM: [Kernel] Add toString() support for generated enum classes

R=vegorov@google.com

Review-Url: https://codereview.chromium.org/2625053003 .

pkg/kernel/lib/analyzer/ast_from_analyzer.dart

@@ -2557,35 +2557,55 @@ class ClassBodyBuilder extends GeneralizingAstVisitor<Null> {
   visitEnumDeclaration(EnumDeclaration node) {
     addAnnotations(node.metadata);
     ast.Class classNode = currentClass;
+
     var intType = scope.loader.getCoreClassReference('int').rawType;
     var indexFieldElement = element.fields.firstWhere(_isIndexField);
     ast.Field indexField = scope.getMemberReference(indexFieldElement);
     indexField.type = intType;
     classNode.addMember(indexField);
-    var parameter = new ast.VariableDeclaration('index', type: intType);
+
+    var stringType = scope.loader.getCoreClassReference('String').rawType;
+    ast.Field nameField = new ast.Field(
+        new ast.Name('_name', scope.currentLibrary),
+        type: stringType,
+        isFinal: true,
+        fileUri: classNode.fileUri);
+    classNode.addMember(nameField);
+
+    var indexParameter = new ast.VariableDeclaration('index', type: intType);
+    var nameParameter = new ast.VariableDeclaration('name', type: stringType);
     var function = new ast.FunctionNode(new ast.EmptyStatement(),
-        positionalParameters: [parameter]);
+        positionalParameters: [indexParameter, nameParameter]);
     var superConstructor = scope.loader.getRootClassConstructorReference();
     var constructor = new ast.Constructor(function,
         name: new ast.Name(''),
         isConst: true,
         initializers: [
-          new ast.FieldInitializer(indexField, new ast.VariableGet(parameter)),
+          new ast.FieldInitializer(
+              indexField, new ast.VariableGet(indexParameter)),
+          new ast.FieldInitializer(
+              nameField, new ast.VariableGet(nameParameter)),
           new ast.SuperInitializer(superConstructor, new ast.Arguments.empty())
         ])..fileOffset = element.nameOffset;
     classNode.addMember(constructor);
+
     int index = 0;
     var enumConstantFields = <ast.Field>[];
     for (var constant in node.constants) {
       ast.Field field = scope.getMemberReference(constant.element);
       field.initializer = new ast.ConstructorInvocation(
-          constructor, new ast.Arguments([new ast.IntLiteral(index)]),
+          constructor,
+          new ast.Arguments([
+            new ast.IntLiteral(index),
+            new ast.StringLiteral('${classNode.name}.${field.name.name}')
+          ]),
           isConst: true)..parent = field;
       field.type = classNode.rawType;
       classNode.addMember(field);
       ++index;
       enumConstantFields.add(field);
     }
+
     // Add the 'values' field.
     var valuesFieldElement = element.fields.firstWhere(_isValuesField);
     ast.Field valuesField = scope.getMemberReference(valuesFieldElement);
@@ -2597,7 +2617,15 @@ class ClassBodyBuilder extends GeneralizingAstVisitor<Null> {
         isConst: true,
         typeArgument: enumType)..parent = valuesField;
     classNode.addMember(valuesField);
-    // TODO: Add the toString method.
+
+    // Add the 'toString()' method.
+    var body = new ast.ReturnStatement(
+        new ast.DirectPropertyGet(new ast.ThisExpression(), nameField));
+    var toStringFunction = new ast.FunctionNode(body, returnType: stringType);
+    var toStringMethod = new ast.Procedure(
+        new ast.Name('toString'), ast.ProcedureKind.Method, toStringFunction,
+        fileUri: classNode.fileUri);
+    classNode.addMember(toStringMethod);
   }
 
   visitClassTypeAlias(ClassTypeAlias node) {

tests/co19/co19-kernel.status

@@ -126,7 +126,6 @@ Language/Classes/Constructors/Generative_Constructors/execution_of_a_superinitia
 Language/Classes/Constructors/Generative_Constructors/execution_of_an_initializer_t02: RuntimeError
 Language/Classes/Constructors/Generative_Constructors/initializing_formals_execution_t02: RuntimeError
 Language/Classes/definition_t23: CompileTimeError
-Language/Enums/declaration_equivalent_t01: RuntimeError
 Language/Expressions/Constants/string_length_t01: Crash
 Language/Expressions/Function_Invocation/Function_Expression_Invocation/not_a_function_expression_t01: RuntimeError
 Language/Expressions/Function_Invocation/Unqualified_Invocation/function_expr_invocation_t03: RuntimeError

tests/language/enum_test.dart

@@ -20,7 +20,7 @@ main() {
   Expect.equals('Enum2.A', Enum2.A.toString());
   Expect.equals(0, Enum2.A.index);
   Expect.listEquals([Enum2.A], Enum2.values);
-  Expect.identical(const [Enum2.A], Enum2.values);
+  Expect.identical(const <Enum2>[Enum2.A], Enum2.values);
   Enum2.values.forEach(test2);
 
   Expect.equals('Enum3.B', Enum3.B.toString());

tests/language/language.status

@@ -11,6 +11,7 @@ async_star_cancel_while_paused_test: RuntimeError
 async_star_pause_test: Fail, OK
 
 [ $compiler == none || $compiler == precompiler || $compiler == app_jit ]
+enum_test: RuntimeError # Issue 28341
 # Other issues:
 generic_methods_type_expression_test: RuntimeError # Issue 25869
 

tests/language/language_dart2js.status

@@ -3,6 +3,7 @@
 # BSD-style license that can be found in the LICENSE file.
 
 [ $compiler == dart2js ]
+enum_test: Fail # Issue 28340
 deferred_not_loaded_check_test: Fail # Issue 27577
 getter_setter_in_lib_test: Fail # Issue 23288
 method_name_test: Fail # issue 25574

tests/language/language_kernel.status

@@ -200,14 +200,6 @@ deferred_type_dependency_test/is: RuntimeError
 deferred_type_dependency_test/none: RuntimeError
 deferred_type_dependency_test/type_annotation: RuntimeError
 duplicate_export_negative_test: Fail
-enum_duplicate_test/01: RuntimeError
-enum_duplicate_test/02: RuntimeError
-enum_duplicate_test/none: RuntimeError
-enum_mirror_test: RuntimeError
-enum_private_test/01: RuntimeError
-enum_private_test/02: RuntimeError
-enum_private_test/none: RuntimeError
-enum_test: RuntimeError
 evaluation_redirecting_constructor_test: RuntimeError
 example_constructor_test: RuntimeError
 external_test/10: MissingRuntimeError