Fix completion value of class declarations.

BUG=v8:6022

Change-Id: I54205cb3ecc2dd31ed62e55726f0ec5fcd202c30
Reviewed-on: https://chromium-review.googlesource.com/446349
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43500}

src/objects-inl.h

@@ -8215,16 +8215,6 @@ static inline Handle<Object> MakeEntryPair(Isolate* isolate, Handle<Name> key,
                                                     FAST_ELEMENTS, 2);
 }
 
-JSIteratorResult* JSIteratorResult::cast(Object* object) {
-  SLOW_DCHECK(object->IsJSObject() &&
-              JSObject::cast(object)->map() ==
-                  JSObject::cast(object)
-                      ->GetIsolate()
-                      ->native_context()
-                      ->iterator_result_map());
-  return reinterpret_cast<JSIteratorResult*>(object);
-}
-
 ACCESSORS(JSIteratorResult, value, Object, kValueOffset)
 ACCESSORS(JSIteratorResult, done, Object, kDoneOffset)
 

src/objects.cc

@@ -20031,8 +20031,12 @@ MaybeHandle<Object> Module::Evaluate(Handle<Module> module) {
   ASSIGN_RETURN_ON_EXCEPTION(
       isolate, result, Execution::Call(isolate, resume, generator, 0, nullptr),
       Object);
-  DCHECK(Handle<JSIteratorResult>::cast(result)->done()->BooleanValue());
-  return handle(Handle<JSIteratorResult>::cast(result)->value(), isolate);
+  DCHECK(static_cast<JSIteratorResult*>(JSObject::cast(*result))
+             ->done()
+             ->BooleanValue());
+  return handle(
+      static_cast<JSIteratorResult*>(JSObject::cast(*result))->value(),
+      isolate);
 }
 
 namespace {

src/objects.h

@@ -2639,9 +2639,8 @@ class JSDataPropertyDescriptor: public JSObject {
 // as specified by ES6 section 25.1.1.3 The IteratorResult Interface
 class JSIteratorResult: public JSObject {
  public:
-  DECLARE_CAST(JSIteratorResult)
-
   DECL_ACCESSORS(value, Object)
+
   DECL_ACCESSORS(done, Object)
 
   // Offsets of object fields.

src/parsing/parser.cc

@@ -1508,12 +1508,14 @@ Statement* Parser::DeclareClass(const AstRawString* variable_name,
   Declaration* decl =
       DeclareVariable(variable_name, LET, class_token_pos, CHECK_OK);
   decl->proxy()->var()->set_initializer_position(end_pos);
+  if (names) names->Add(variable_name, zone());
+
   Assignment* assignment = factory()->NewAssignment(Token::INIT, decl->proxy(),
                                                     value, class_token_pos);
-  Statement* assignment_statement =
-      factory()->NewExpressionStatement(assignment, kNoSourcePosition);
-  if (names) names->Add(variable_name, zone());
-  return assignment_statement;
+  Block* block = factory()->NewBlock(nullptr, 1, true, kNoSourcePosition);
+  block->statements()->Add(
+      factory()->NewExpressionStatement(assignment, kNoSourcePosition), zone());
+  return block;
 }
 
 Statement* Parser::DeclareNative(const AstRawString* name, int pos, bool* ok) {

test/cctest/test-modules.cc

@@ -104,14 +104,21 @@ TEST(ModuleEvaluationCompletion1) {
   LocalContext env;
 
   const char* sources[] = {
-      "", "var a = 1", "import '42'", "export * from '42'",
-      "export {} from '42'", "export {}", "var a = 1; export {a}",
+      "",
+      "var a = 1",
+      "import '42'",
+      "export * from '42'",
+      "export {} from '42'",
+      "export {}",
+      "var a = 1; export {a}",
       "export function foo() {}",
-      // TODO(neis): v8:6022 "export class C extends null {}",
-      "export let a = 1", "export default 1",
-      "export default function foo() {}", "export default function () {}",
+      "export class C extends null {}",
+      "export let a = 1",
+      "export default 1",
+      "export default function foo() {}",
+      "export default function () {}",
       "export default (function () {})",
-      // TODO(neis): v8:6022 "export default class C extends null {}",
+      "export default class C extends null {}",
       "export default (class C extends null {})",
       "for (var i = 0; i < 5; ++i) {}",
   };
@@ -134,16 +141,21 @@ TEST(ModuleEvaluationCompletion2) {
   LocalContext env;
 
   const char* sources[] = {
-      "'gaga'; ", "'gaga'; var a = 1", "'gaga'; import '42'",
-      "'gaga'; export * from '42'", "'gaga'; export {} from '42'",
-      "'gaga'; export {}", "'gaga'; var a = 1; export {a}",
+      "'gaga'; ",
+      "'gaga'; var a = 1",
+      "'gaga'; import '42'",
+      "'gaga'; export * from '42'",
+      "'gaga'; export {} from '42'",
+      "'gaga'; export {}",
+      "'gaga'; var a = 1; export {a}",
       "'gaga'; export function foo() {}",
-      // TODO(neis): v8:6022 "'gaga'; export class C extends null {}",
-      "'gaga'; export let a = 1", "'gaga'; export default 1",
+      "'gaga'; export class C extends null {}",
+      "'gaga'; export let a = 1",
+      "'gaga'; export default 1",
       "'gaga'; export default function foo() {}",
       "'gaga'; export default function () {}",
       "'gaga'; export default (function () {})",
-      // TODO(neis): v8:6022 "'gaga'; export default class C extends null {}",
+      "'gaga'; export default class C extends null {}",
       "'gaga'; export default (class C extends null {})",
   };
 

test/mjsunit/es6/classes.js

@@ -628,7 +628,7 @@ function assertAccessorDescriptor(object, name) {
 (function TestConstructorCall(){
   var realmIndex = Realm.create();
   var otherTypeError = Realm.eval(realmIndex, "TypeError");
-  var A = Realm.eval(realmIndex, '"use strict"; class A {}');
+  var A = Realm.eval(realmIndex, '"use strict"; class A {}; A');
   var instance = new A();
   var constructor = instance.constructor;
   var otherTypeError = Realm.eval(realmIndex, 'TypeError');

test/mjsunit/es6/completion.js

@@ -8,6 +8,16 @@ function assertUndef(x) {
 }
 
 
+// ClassDeclaration
+
+assertUndef(eval('class C {}'));
+assertUndef(eval('class C {m() {}}'));
+assertUndef(eval('class C extends null {}'));
+assertEquals(42, eval('42; class C {}'));
+assertEquals(42, eval('42; class C {m() {}}'));
+assertEquals(42, eval('42; class C extends null {}'));
+
+
 // IfStatement [13.6.7]
 
 assertUndef(eval('42; if (true) ; else 0;'));  // ES5: 42