ES6: Add support for Map.prototype.forEach and Set.prototype.forEach

src/bootstrapper.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "bootstrapper.h"
 
 #include "accessors.h"
 #include "isolate-inl.h"
 #include "natives.h"
 #include "snapshot.h"
@@ skipping 1285 matching lines @@
     {  // -- M a p
       InstallFunction(global, "Map", JS_MAP_TYPE, JSMap::kSize,
                       isolate()->initial_object_prototype(),
                       Builtins::kIllegal, true, true);
     }
     {  // -- S e t
       InstallFunction(global, "Set", JS_SET_TYPE, JSSet::kSize,
                       isolate()->initial_object_prototype(),
                       Builtins::kIllegal, true, true);
     }
+    {   // -- S e t I t e r a t o r
+      Handle<Map> map = isolate()->factory()->NewMap(
+          JS_SET_ITERATOR_TYPE, JSSetIterator::kSize);
+      native_context()->set_set_iterator_map(*map);
+    }
+    {   // -- M a p I t e r a t o r
+      Handle<Map> map = isolate()->factory()->NewMap(
+          JS_MAP_ITERATOR_TYPE, JSMapIterator::kSize);
+      native_context()->set_map_iterator_map(*map);
+    }
   }
 
   if (FLAG_harmony_weak_collections) {
     {  // -- W e a k M a p
       InstallFunction(global, "WeakMap", JS_WEAK_MAP_TYPE, JSWeakMap::kSize,
                       isolate()->initial_object_prototype(),
                       Builtins::kIllegal, true, true);
     }
     {  // -- W e a k S e t
       InstallFunction(global, "WeakSet", JS_WEAK_SET_TYPE, JSWeakSet::kSize,
@@ skipping 34 matching lines @@
     native_context()->set_strict_generator_function_map(
         *strict_mode_generator_function_map);
 
     Handle<JSFunction> object_function(native_context()->object_function());
     Handle<Map> generator_object_prototype_map = Map::Create(
         object_function, 0);
     generator_object_prototype_map->set_prototype(
         *generator_object_prototype);
     native_context()->set_generator_object_prototype_map(
         *generator_object_prototype_map);
+    ASSERT(object_function->initial_map()->inobject_properties() == 0);

[Michael Starzinger, 2014/04/15 16:13:56]

nit: This assert belongs to the code creating the "iterator_result_map" I think.
It ensures that the "Object" map can be used as a base for result object map.
Can we move it down?

[arv (Not doing code reviews), 2014/04/15 17:07:23]

Done.

+  }
 
-    // Create a map for generator result objects.
-    ASSERT(object_function->initial_map()->inobject_properties() == 0);
+  if (FLAG_harmony_collections || FLAG_harmony_generators) {
+    // Collection forEach uses an iterator result object.
+    // Generators return iteraror result objects.
+
     STATIC_ASSERT(JSGeneratorObject::kResultPropertyCount == 2);
-    Handle<Map> generator_result_map = Map::Create(
+    Handle<JSFunction> object_function(native_context()->object_function());
+    Handle<Map> iterator_result_map = Map::Create(
         object_function, JSGeneratorObject::kResultPropertyCount);
-    ASSERT(generator_result_map->inobject_properties() ==
+    ASSERT(iterator_result_map->inobject_properties() ==
         JSGeneratorObject::kResultPropertyCount);
     Map::EnsureDescriptorSlack(
-        generator_result_map, JSGeneratorObject::kResultPropertyCount);
+        iterator_result_map, JSGeneratorObject::kResultPropertyCount);
 
     Handle<String> value_string = factory()->InternalizeOneByteString(
         STATIC_ASCII_VECTOR("value"));
     FieldDescriptor value_descr(value_string,
                                 JSGeneratorObject::kResultValuePropertyIndex,
                                 NONE,
                                 Representation::Tagged());
-    generator_result_map->AppendDescriptor(&value_descr);
+    iterator_result_map->AppendDescriptor(&value_descr);
 
     Handle<String> done_string = factory()->InternalizeOneByteString(
         STATIC_ASCII_VECTOR("done"));
     FieldDescriptor done_descr(done_string,
                                JSGeneratorObject::kResultDonePropertyIndex,
                                NONE,
                                Representation::Tagged());
-    generator_result_map->AppendDescriptor(&done_descr);
+    iterator_result_map->AppendDescriptor(&done_descr);
 
-    generator_result_map->set_unused_property_fields(0);
+    iterator_result_map->set_unused_property_fields(0);
     ASSERT_EQ(JSGeneratorObject::kResultSize,
-              generator_result_map->instance_size());
-    native_context()->set_generator_result_map(*generator_result_map);
+              iterator_result_map->instance_size());
+    native_context()->set_iterator_result_map(*iterator_result_map);
   }
 }
 
 
 bool Genesis::CompileBuiltin(Isolate* isolate, int index) {
   Vector<const char> name = Natives::GetScriptName(index);
   Handle<String> source_code =
       isolate->bootstrapper()->NativesSourceLookup(index);
   return CompileNative(isolate, name, source_code);
 }
@@ skipping 1287 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   ASSERT(!IsActive());
 }
 
 } }  // namespace v8::internal