Pre-create properties on JSRegExp objects

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 8a9fa4bf69741185e0af36912d653822555ee6a3..717bb2544a8ceadc0d587d62d77d0c35546b3c07 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -723,8 +723,67 @@ void Genesis::InitializeGlobal(Handle<GlobalObject> inner_global,
         InstallFunction(global, "RegExp", JS_REGEXP_TYPE, JSRegExp::kSize,
                         Top::initial_object_prototype(), Builtins::Illegal,
                         true);
-
     global_context()->set_regexp_function(*regexp_fun);
+
+    ASSERT(regexp_fun->has_initial_map());
+    Handle<Map> initial_map(regexp_fun->initial_map());
+
+    ASSERT_EQ(0, initial_map->inobject_properties());
+
+    Handle<DescriptorArray> descriptors = Factory::NewDescriptorArray(5);
+    PropertyAttributes final =
+        static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
+    {
+      // ECMA-262, section 15.10.7.1.
+      FieldDescriptor field(Heap::source_symbol(),
+                            JSRegExp::kSourceFieldIndex,
+                            final,
+                            0);
+      descriptors->Set(0, &field);
+    }
+    {
+      // ECMA-262, section 15.10.7.2.
+      FieldDescriptor field(Heap::global_symbol(),
+                            JSRegExp::kGlobalFieldIndex,
+                            final,
+                            1);
+      descriptors->Set(1, &field);
+    }
+    {
+      // ECMA-262, section 15.10.7.3.
+      FieldDescriptor field(Heap::ignore_case_symbol(),
+                            JSRegExp::kIgnoreCaseFieldIndex,
+                            final,
+                            2);
+      descriptors->Set(2, &field);
+    }
+    {
+      // ECMA-262, section 15.10.7.4.
+      FieldDescriptor field(Heap::multiline_symbol(),
+                            JSRegExp::kMultilineFieldIndex,
+                            final,
+                            3);

[Erik Corry, 2010/03/26 13:51:34]

You already made a constant for this '3'.

[Lasse Reichstein, 2010/03/26 14:19:09]

Actually, not. This "3" is the enumeration index, not the field index. They just
happen to be the same value.

However, I'm not sure whether I need an index at all, since the value is not
enumerable.
I'll turn it into a counter. Easier to read that way, and the compiler should
constant fold it anyway.

+      descriptors->Set(3, &field);
+    }
+    {
+      // ECMA-262, section 15.10.7.5.
+      PropertyAttributes writable =
+          static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE);
+      FieldDescriptor field(Heap::last_index_symbol(),
+                            JSRegExp::kLastIndexFieldIndex,
+                            writable,
+                            4);
+      descriptors->Set(4, &field);
+    }
+    descriptors->SetNextEnumerationIndex(5);
+    descriptors->Sort();
+
+    initial_map->set_inobject_properties(5);
+    initial_map->set_pre_allocated_property_fields(5);
+    initial_map->set_unused_property_fields(0);
+    initial_map->set_instance_size(
+        initial_map->instance_size() + 5 * kPointerSize);
+    initial_map->set_instance_descriptors(*descriptors);
   }
 
   {  // -- J S O N