[builtins] Migrate Object.keys to C++.

Everything necessary to implement Object.keys efficiently is already
available in C++ land for quite some time now, and only the thin
JavaScript wrapper was left, so get rid of that as well and move the
whole builtin to C++ instead.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1567963002

Cr-Commit-Position: refs/heads/master@{#33167}

src/bootstrapper.cc

@@ -1105,6 +1105,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     Handle<JSFunction> object_is_sealed = SimpleInstallFunction(
         object_function, "isSealed", Builtins::kObjectIsSealed, 1, false);
     native_context()->set_object_is_sealed(*object_is_sealed);
+    Handle<JSFunction> object_keys = SimpleInstallFunction(
+        object_function, "keys", Builtins::kObjectKeys, 1, false);
+    native_context()->set_object_keys(*object_keys);
     SimpleInstallFunction(object_function, "preventExtensions",
                           Builtins::kObjectPreventExtensions, 1, false);
     SimpleInstallFunction(object_function, "seal", Builtins::kObjectSeal, 1,

src/builtins.cc

@@ -1602,6 +1602,22 @@ BUILTIN(ObjectIsSealed) {
 }
 
 
+// ES6 section 19.1.2.14 Object.keys ( O )
+BUILTIN(ObjectKeys) {
+  HandleScope scope(isolate);
+  Handle<Object> object = args.atOrUndefined(isolate, 1);
+  Handle<JSReceiver> receiver;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, receiver,
+                                     Execution::ToObject(isolate, object));
+  Handle<FixedArray> keys;
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+      isolate, keys,
+      JSReceiver::GetKeys(receiver, JSReceiver::OWN_ONLY, ENUMERABLE_STRINGS,
+                          CONVERT_TO_STRING));
+  return *isolate->factory()->NewJSArrayWithElements(keys);
+}
+
+
 // ES6 section 19.1.2.15 Object.preventExtensions ( O )
 BUILTIN(ObjectPreventExtensions) {
   HandleScope scope(isolate);

src/builtins.h

@@ -92,6 +92,7 @@ inline bool operator&(BuiltinExtraArguments lhs, BuiltinExtraArguments rhs) {
   V(ObjectIsExtensible, kNone)                                 \
   V(ObjectIsFrozen, kNone)                                     \
   V(ObjectIsSealed, kNone)                                     \
+  V(ObjectKeys, kNone)                                         \
   V(ObjectPreventExtensions, kNone)                            \
   V(ObjectSeal, kNone)                                         \
   V(ObjectProtoToString, kNone)                                \

src/contexts.h

@@ -87,6 +87,7 @@ enum BindingFlags {
   V(OBJECT_IS_EXTENSIBLE, JSFunction, object_is_extensible)               \
   V(OBJECT_IS_FROZEN, JSFunction, object_is_frozen)                       \
   V(OBJECT_IS_SEALED, JSFunction, object_is_sealed)                       \
+  V(OBJECT_KEYS, JSFunction, object_keys)                                 \
   V(REFLECT_APPLY_INDEX, JSFunction, reflect_apply)                       \
   V(REFLECT_CONSTRUCT_INDEX, JSFunction, reflect_construct)               \
   V(REFLECT_DEFINE_PROPERTY_INDEX, JSFunction, reflect_define_property)   \

src/execution.cc

@@ -421,13 +421,15 @@ void StackGuard::InitThread(const ExecutionAccess& lock) {
 // --- C a l l s   t o   n a t i v e s ---
 
 
-MaybeHandle<Object> Execution::ToObject(Isolate* isolate, Handle<Object> obj) {
+MaybeHandle<JSReceiver> Execution::ToObject(Isolate* isolate,
+                                            Handle<Object> obj) {
   Handle<JSReceiver> receiver;
   if (JSReceiver::ToObject(isolate, obj).ToHandle(&receiver)) {
     return receiver;
   }
-  THROW_NEW_ERROR(
-      isolate, NewTypeError(MessageTemplate::kUndefinedOrNullToObject), Object);
+  THROW_NEW_ERROR(isolate,
+                  NewTypeError(MessageTemplate::kUndefinedOrNullToObject),
+                  JSReceiver);
 }
 
 

src/execution.h

@@ -50,8 +50,8 @@ class Execution final : public AllStatic {
                                      MaybeHandle<Object>* exception_out = NULL);
 
   // ECMA-262 9.9
-  MUST_USE_RESULT static MaybeHandle<Object> ToObject(
-      Isolate* isolate, Handle<Object> obj);
+  MUST_USE_RESULT static MaybeHandle<JSReceiver> ToObject(Isolate* isolate,
+                                                          Handle<Object> obj);
 
   static Handle<String> GetStackTraceLine(Handle<Object> recv,
                                           Handle<JSFunction> fun,

src/js/json.js

@@ -18,7 +18,6 @@ var MakeTypeError;
 var MaxSimple;
 var MinSimple;
 var ObjectHasOwnProperty;
-var ObjectKeys;
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 utils.Import(function(from) {
@@ -26,7 +25,6 @@ utils.Import(function(from) {
   MaxSimple = from.MaxSimple;
   MinSimple = from.MinSimple;
   ObjectHasOwnProperty = from.ObjectHasOwnProperty;
-  ObjectKeys = from.ObjectKeys;
 });
 
 // -------------------------------------------------------------------
@@ -52,7 +50,7 @@ function InternalizeJSONProperty(holder, name, reviver) {
         }
       }
     } else {
-      for (var p of ObjectKeys(val)) {
+      for (var p of %object_keys(val)) {
         var newElement = InternalizeJSONProperty(val, p, reviver);
         if (IS_UNDEFINED(newElement)) {
           %reflect_delete_property(val, p);
@@ -123,7 +121,7 @@ function SerializeObject(value, replacer, stack, indent, gap) {
       }
     }
   } else {
-    for (var p of ObjectKeys(value)) {
+    for (var p of %object_keys(value)) {
       var strP = JSONSerialize(p, value, replacer, stack, indent, gap);
       if (!IS_UNDEFINED(strP)) {
         var member = %QuoteJSONString(p) + ":";

src/js/v8natives.js

@@ -211,13 +211,6 @@ function ObjectLookupSetter(name) {
 }
 
 
-function ObjectKeys(obj) {
-  obj = TO_OBJECT(obj);
-  var filter = PROPERTY_FILTER_ONLY_ENUMERABLE | PROPERTY_FILTER_SKIP_SYMBOLS;
-  return %GetOwnPropertyKeys(obj, filter);
-}
-
-
 // ES6 6.2.4.1
 function IsAccessorDescriptor(desc) {
   if (IS_UNDEFINED(desc)) return false;
@@ -892,7 +885,7 @@ utils.InstallGetterSetter(GlobalObject.prototype, "__proto__", ObjectGetProto,
 // Set up non-enumerable functions in the Object object.
 utils.InstallFunctions(GlobalObject, DONT_ENUM, [
   // assign is added in bootstrapper.cc.
-  "keys", ObjectKeys,
+  // keys is added in bootstrapper.cc.
   "defineProperty", ObjectDefineProperty,
   "defineProperties", ObjectDefineProperties,
   "getPrototypeOf", ObjectGetPrototypeOf,
@@ -1210,7 +1203,6 @@ utils.Export(function(to) {
   to.ObjectDefineProperties = ObjectDefineProperties;
   to.ObjectDefineProperty = ObjectDefineProperty;
   to.ObjectHasOwnProperty = ObjectHasOwnProperty;
-  to.ObjectKeys = ObjectKeys;
 });
 
 %InstallToContext([