Pre-create properties on JSRegExp objects

src/bootstrapper.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 705 matching lines @@
     global_context()->set_date_function(*date_fun);
   }
 
 
   {  // -- R e g E x p
     // Builtin functions for RegExp.prototype.
     Handle<JSFunction> regexp_fun =
         InstallFunction(global, "RegExp", JS_REGEXP_TYPE, JSRegExp::kSize,
                         Top::initial_object_prototype(), Builtins::Illegal,
                         true);
+    global_context()->set_regexp_function(*regexp_fun);
 
-    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
     Handle<String> name = Factory::NewStringFromAscii(CStrVector("JSON"));
     Handle<JSFunction> cons = Factory::NewFunction(
         name,
         Factory::the_hole_value());
     cons->SetInstancePrototype(global_context()->initial_object_prototype());
     cons->SetInstanceClassName(*name);
     Handle<JSObject> json_object = Factory::NewJSObject(cons, TENURED);
@@ skipping 861 matching lines @@
 }
 
 
 // Restore statics that are thread local.
 char* BootstrapperActive::RestoreState(char* from) {
   nesting_ = *reinterpret_cast<int*>(from);
   return from + sizeof(nesting_);
 }
 
 } }  // namespace v8::internal