Native construction of RegExp result objects, with in-object index and input.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 82a63f0ae60e1474d5c2a66ecc2c018cea6ea8ff..9796bb18258ac005f70e4bd017e8a4e88b96c3c1 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1237,6 +1237,62 @@ bool Genesis::InstallNatives() {
     apply->shared()->set_length(2);
   }
 
+  // Create a constructor for RegExp results (a variant of Array that
+  // predefines the two properties index and match).
+  {
+    // RegExpResult initial map.
+
+    // Find global.Array.prototype to inherit from.
+    Handle<JSFunction> array_constructor(global_context()->array_function());
+    Handle<JSObject> array_prototype(
+        JSObject::cast(array_constructor->instance_prototype()));
+
+    // Add initial map.
+    Handle<Map> initial_map =
+        Factory::NewMap(JS_ARRAY_TYPE, JSArray::kRegExpResultSize);
+    initial_map->set_constructor(*array_constructor);
+
+    // Set prototype on map.
+    initial_map->set_non_instance_prototype(false);
+    initial_map->set_prototype(*array_prototype);
+
+    // Update map with length accessor from Array and add "index" and "input".
+    Handle<Map> array_map(global_context()->js_array_map());
+    Handle<DescriptorArray> array_descriptors(
+        array_map->instance_descriptors());
+    ASSERT_EQ(1, array_descriptors->number_of_descriptors());
+
+    Handle<DescriptorArray> reresult_descriptors =
+        Factory::NewDescriptorArray(3);
+
+    reresult_descriptors->CopyFrom(0, *array_descriptors, 0);
+
+    int enum_index = 0;
+    {
+      FieldDescriptor index_field(Heap::index_symbol(),

[Søren Thygesen Gjesse, 2010/04/13 07:22:29]

Move the constant to JSRegExpResult (see comment in objects.h).

[Lasse Reichstein, 2010/04/13 09:50:56]

Done.

+                                  JSArray::kIndexIndex,
+                                  NONE,
+                                  enum_index++);
+      reresult_descriptors->Set(1, &index_field);
+    }
+
+    {
+      FieldDescriptor input_field(Heap::input_symbol(),

[Søren Thygesen Gjesse, 2010/04/13 07:22:29]

Ditto.

[Lasse Reichstein, 2010/04/13 09:50:56]

Done too.

+                                  JSArray::kInputIndex,
+                                  NONE,
+                                  enum_index++);
+      reresult_descriptors->Set(2, &input_field);
+    }
+    reresult_descriptors->Sort();
+
+    initial_map->set_inobject_properties(2);
+    initial_map->set_pre_allocated_property_fields(2);
+    initial_map->set_unused_property_fields(0);
+    initial_map->set_instance_descriptors(*reresult_descriptors);
+
+    global_context()->set_regexp_result_map(*initial_map);
+  }
+
 #ifdef DEBUG
   builtins->Verify();
 #endif