[builtins] Properly optimize TypedArray/DataView accessors.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 5e6ff7a9f6b910716221a63f4295137072d74b6b..c70cd1d28bc1e77a65f14f5f1ebd9e6a273703b2 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -379,6 +379,16 @@ void InstallFunction(Handle<JSObject> target, Handle<JSFunction> function,
   InstallFunction(target, name, function, name_string, attributes);
 }
 
+Handle<JSFunction> InstallGetter(Handle<JSObject> target,
+                                 Handle<Name> property_name,
+                                 Handle<JSFunction> getter,
+                                 PropertyAttributes attributes = DONT_ENUM) {
+  Handle<Object> setter = target->GetIsolate()->factory()->undefined_value();
+  JSObject::DefineAccessor(target, property_name, getter, setter, attributes)
+      .Check();
+  return getter;
+}
+
 Handle<JSFunction> CreateFunction(Isolate* isolate, Handle<String> name,
                                   InstanceType type, int instance_size,
                                   MaybeHandle<JSObject> maybe_prototype,
@@ -456,6 +466,27 @@ Handle<JSFunction> SimpleInstallFunction(Handle<JSObject> base,
                                len, adapt);
 }
 
+Handle<JSFunction> SimpleInstallGetter(Handle<JSObject> base,
+                                       Handle<String> name, Builtins::Name call,
+                                       bool adapt) {
+  Isolate* const isolate = base->GetIsolate();
+  Handle<String> fun_name =
+      Name::ToFunctionName(name, isolate->factory()->get_string())
+          .ToHandleChecked();
+  Handle<JSFunction> fun =
+      SimpleCreateFunction(isolate, fun_name, call, 0, adapt);
+  InstallGetter(base, name, fun);
+  return fun;
+}
+
+Handle<JSFunction> SimpleInstallGetter(Handle<JSObject> base,
+                                       Handle<String> name, Builtins::Name call,
+                                       bool adapt, BuiltinFunctionId id) {
+  Handle<JSFunction> fun = SimpleInstallGetter(base, name, call, adapt);
+  fun->shared()->set_builtin_function_id(id);
+  return fun;
+}
+
 }  // namespace
 
 void Genesis::SetFunctionInstanceDescriptor(Handle<Map> map,
@@ -1654,6 +1685,32 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                                      Context::ARRAY_BUFFER_FUN_INDEX);
   }
 
+  {  // -- T y p e d A r r a y
+    Handle<JSObject> prototype =
+        factory->NewJSObject(isolate->object_function(), TENURED);
+    Handle<JSFunction> typed_array_fun =
+        InstallFunction(global, "TypedArray", JS_TYPED_ARRAY_TYPE,
+                        JSTypedArray::kSize, prototype, Builtins::kIllegal);
+
+    // Install the "constructor" property on the {prototype}.
+    JSObject::AddProperty(prototype, factory->constructor_string(),
+                          typed_array_fun, DONT_ENUM);
+
+    // Install the "buffer", "byteOffset", "byteLength" and "length"
+    // getters on the {prototype}.
+    SimpleInstallGetter(prototype, factory->buffer_string(),
+                        Builtins::kTypedArrayPrototypeBuffer, false);
+    SimpleInstallGetter(prototype, factory->byte_length_string(),
+                        Builtins::kTypedArrayPrototypeByteLength, true,
+                        kTypedArrayByteLength);
+    SimpleInstallGetter(prototype, factory->byte_offset_string(),
+                        Builtins::kTypedArrayPrototypeByteOffset, true,
+                        kTypedArrayByteOffset);
+    SimpleInstallGetter(prototype, factory->length_string(),
+                        Builtins::kTypedArrayPrototypeLength, true,
+                        kTypedArrayLength);
+  }
+
   {  // -- T y p e d A r r a y s
 #define INSTALL_TYPED_ARRAY(Type, type, TYPE, ctype, size)             \
   {                                                                    \
@@ -1664,17 +1721,43 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
   }
     TYPED_ARRAYS(INSTALL_TYPED_ARRAY)
 #undef INSTALL_TYPED_ARRAY
+  }
 
-    Handle<JSFunction> data_view_fun = InstallFunction(
-        global, "DataView", JS_DATA_VIEW_TYPE,
-        JSDataView::kSizeWithInternalFields,
-        isolate->initial_object_prototype(), Builtins::kDataViewConstructor);
+  {  // -- D a t a V i e w
+    Handle<JSObject> prototype =
+        factory->NewJSObject(isolate->object_function(), TENURED);
+    Handle<JSFunction> data_view_fun =
+        InstallFunction(global, "DataView", JS_DATA_VIEW_TYPE,
+                        JSDataView::kSizeWithInternalFields, prototype,
+                        Builtins::kDataViewConstructor);
     InstallWithIntrinsicDefaultProto(isolate, data_view_fun,
                                      Context::DATA_VIEW_FUN_INDEX);
     data_view_fun->shared()->set_construct_stub(
         *isolate->builtins()->DataViewConstructor_ConstructStub());
     data_view_fun->shared()->set_length(3);
     data_view_fun->shared()->DontAdaptArguments();
+
+    // Install the @@toStringTag property on the {prototype}.
+    JSObject::AddProperty(
+        prototype, factory->to_string_tag_symbol(),
+        factory->NewStringFromAsciiChecked("DataView"),
+        static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
+
+    // Install the "constructor" property on the {prototype}.
+    JSObject::AddProperty(prototype, factory->constructor_string(),
+                          data_view_fun, DONT_ENUM);
+
+    // Install the "buffer", "byteOffset" and "byteLength" getters
+    // on the {prototype}.
+    SimpleInstallGetter(prototype, factory->buffer_string(),
+                        Builtins::kDataViewPrototypeGetBuffer, false,
+                        kDataViewBuffer);
+    SimpleInstallGetter(prototype, factory->byte_length_string(),
+                        Builtins::kDataViewPrototypeGetByteLength, false,
+                        kDataViewByteLength);
+    SimpleInstallGetter(prototype, factory->byte_offset_string(),
+                        Builtins::kDataViewPrototypeGetByteOffset, false,
+                        kDataViewByteOffset);
   }
 
   {  // -- M a p