RegExp.prototype is an ordinary object.

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 "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/code-stubs.h"
@@ skipping 1080 matching lines @@
   // Set extension and global object.
   native_context()->set_extension(*global_object);
   native_context()->set_global_object(*global_object);
   // Security setup: Set the security token of the native context to the global
   // object. This makes the security check between two different contexts fail
   // by default even in case of global object reinitialization.
   native_context()->set_security_token(*global_object);
 
   Isolate* isolate = global_object->GetIsolate();
   Factory* factory = isolate->factory();
-  Heap* heap = isolate->heap();
 
   Handle<ScriptContextTable> script_context_table =
       factory->NewScriptContextTable();
   native_context()->set_script_context_table(*script_context_table);
   InstallGlobalThisBinding();
 
   Handle<String> object_name = factory->Object_string();
   JSObject::AddProperty(
       global_object, object_name, isolate->object_function(), DONT_ENUM);
 
@@ skipping 168 matching lines @@
                            JSRegExp::kLastIndexFieldIndex, writable,
                            Representation::Tagged());
       initial_map->AppendDescriptor(&field);
     }
 
     static const int num_fields = JSRegExp::kInObjectFieldCount;
     initial_map->SetInObjectProperties(num_fields);
     initial_map->set_unused_property_fields(0);
     initial_map->set_instance_size(initial_map->instance_size() +
                                    num_fields * kPointerSize);
-
-    // RegExp prototype object is itself a RegExp.
-    Handle<Map> proto_map = Map::Copy(initial_map, "RegExpPrototype");
-    DCHECK(proto_map->prototype() == *isolate->initial_object_prototype());
-    Handle<JSObject> proto = factory->NewJSObjectFromMap(proto_map);
-    proto->InObjectPropertyAtPut(JSRegExp::kSourceFieldIndex,
-                                 heap->query_colon_string());
-    proto->InObjectPropertyAtPut(JSRegExp::kGlobalFieldIndex,
-                                 heap->false_value());
-    proto->InObjectPropertyAtPut(JSRegExp::kIgnoreCaseFieldIndex,
-                                 heap->false_value());
-    proto->InObjectPropertyAtPut(JSRegExp::kMultilineFieldIndex,
-                                 heap->false_value());
-    proto->InObjectPropertyAtPut(JSRegExp::kLastIndexFieldIndex,
-                                 Smi::FromInt(0),
-                                 SKIP_WRITE_BARRIER);  // It's a Smi.
-    proto_map->set_is_prototype_map(true);
-    Map::SetPrototype(initial_map, proto);
-    factory->SetRegExpIrregexpData(Handle<JSRegExp>::cast(proto),
-                                   JSRegExp::IRREGEXP, factory->empty_string(),
-                                   JSRegExp::Flags(0), 0);
   }
 
   // Initialize the embedder data slot.
   Handle<FixedArray> embedder_data = factory->NewFixedArray(3);
   native_context()->set_embedder_data(*embedder_data);
 
   if (context_type == THIN_CONTEXT) return;
 
   {  // -- J S O N
     Handle<String> name = factory->InternalizeUtf8String("JSON");
@@ skipping 2001 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8