Remove separate maps for function instances

src/bootstrapper.cc

 // Copyright 2012 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 263 matching lines @@
                                   Handle<String> source,
                                   SourceCodeCache* cache,
                                   v8::Extension* extension,
                                   Handle<Context> top_context,
                                   bool use_runtime_context);
 
   Isolate* isolate_;
   Handle<Context> result_;
   Handle<Context> native_context_;
 
-  // Function instance maps. Function literal maps are created initially with
-  // a read only prototype for the processing of JS builtins. Later the function
-  // instance maps are replaced in order to make prototype writable.
-  // These are the final, writable prototype, maps.
-  Handle<Map> function_instance_map_writable_prototype_;
-  Handle<Map> strict_mode_function_instance_map_writable_prototype_;
+  // Function maps. Function maps are created initially with a read only
+  // prototype for the processing of JS builtins. Later the function maps are
+  // replaced in order to make prototype writable. These are the final, writable
+  // prototype, maps.
+  Handle<Map> function_map_writable_prototype_;
+  Handle<Map> strict_mode_function_map_writable_prototype_;
   Handle<JSFunction> throw_type_error_function;
 
   BootstrapperActive active_;
   friend class Bootstrapper;
 };
 
 
 void Bootstrapper::Iterate(ObjectVisitor* v) {
   extensions_cache_.Iterate(v);
   v->Synchronize(VisitorSynchronization::kExtensions);
@@ skipping 130 matching lines @@
   SetFunctionInstanceDescriptor(map, prototype_mode);
   map->set_function_with_prototype(prototype_mode != DONT_ADD_PROTOTYPE);
   return map;
 }
 
 
 Handle<JSFunction> Genesis::CreateEmptyFunction(Isolate* isolate) {
   // Allocate the map for function instances. Maps are allocated first and their
   // prototypes patched later, once empty function is created.
 
-  // Please note that the prototype property for function instances must be
-  // writable.
-  Handle<Map> function_instance_map =
-      CreateFunctionMap(ADD_WRITEABLE_PROTOTYPE);
-  native_context()->set_function_instance_map(*function_instance_map);
-
   // Functions with this map will not have a 'prototype' property, and
   // can not be used as constructors.
   Handle<Map> function_without_prototype_map =
       CreateFunctionMap(DONT_ADD_PROTOTYPE);
   native_context()->set_function_without_prototype_map(
       *function_without_prototype_map);
 
   // Allocate the function map. This map is temporary, used only for processing
   // of builtins.
   // Later the map is replaced with writable prototype map, allocated below.
   Handle<Map> function_map = CreateFunctionMap(ADD_READONLY_PROTOTYPE);
   native_context()->set_function_map(*function_map);
 
   // The final map for functions. Writeable prototype.
   // This map is installed in MakeFunctionInstancePrototypeWritable.
-  function_instance_map_writable_prototype_ =
-      CreateFunctionMap(ADD_WRITEABLE_PROTOTYPE);
+  function_map_writable_prototype_ = CreateFunctionMap(ADD_WRITEABLE_PROTOTYPE);
 
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
 
   Handle<String> object_name = Handle<String>(heap->Object_string());
 
   {  // --- O b j e c t ---
     Handle<JSFunction> object_fun =
         factory->NewFunction(object_name, factory->null_value());
     Handle<Map> object_function_map =
@@ skipping 29 matching lines @@
       factory->NewStringFromOneByte(STATIC_ASCII_VECTOR("() {}"));
   Handle<Script> script = factory->NewScript(source);
   script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
   empty_function->shared()->set_script(*script);
   empty_function->shared()->set_start_position(0);
   empty_function->shared()->set_end_position(source->length());
   empty_function->shared()->DontAdaptArguments();
 
   // Set prototypes for the function maps.
   native_context()->function_map()->set_prototype(*empty_function);
-  native_context()->function_instance_map()->set_prototype(*empty_function);
   native_context()->function_without_prototype_map()->
       set_prototype(*empty_function);
-  function_instance_map_writable_prototype_->set_prototype(*empty_function);
+  function_map_writable_prototype_->set_prototype(*empty_function);
 
   // Allocate the function map first and then patch the prototype later
   Handle<Map> empty_function_map = CreateFunctionMap(DONT_ADD_PROTOTYPE);
   empty_function_map->set_prototype(
       native_context()->object_function()->prototype());
   empty_function->set_map(*empty_function_map);
   return empty_function;
 }
 
 
@@ skipping 68 matching lines @@
     Handle<JSFunction> empty_function) {
   Handle<Map> map = factory()->NewMap(JS_FUNCTION_TYPE, JSFunction::kSize);
   SetStrictFunctionInstanceDescriptor(map, prototype_mode);
   map->set_function_with_prototype(prototype_mode != DONT_ADD_PROTOTYPE);
   map->set_prototype(*empty_function);
   return map;
 }
 
 
 void Genesis::CreateStrictModeFunctionMaps(Handle<JSFunction> empty) {
-  // Allocate map for the strict mode function instances.
-  Handle<Map> strict_mode_function_instance_map =
-      CreateStrictModeFunctionMap(ADD_WRITEABLE_PROTOTYPE, empty);
-  native_context()->set_strict_mode_function_instance_map(
-      *strict_mode_function_instance_map);
-
   // Allocate map for the prototype-less strict mode instances.
   Handle<Map> strict_mode_function_without_prototype_map =
       CreateStrictModeFunctionMap(DONT_ADD_PROTOTYPE, empty);
   native_context()->set_strict_mode_function_without_prototype_map(
       *strict_mode_function_without_prototype_map);
 
   // Allocate map for the strict mode functions. This map is temporary, used
   // only for processing of builtins.
   // Later the map is replaced with writable prototype map, allocated below.
   Handle<Map> strict_mode_function_map =
       CreateStrictModeFunctionMap(ADD_READONLY_PROTOTYPE, empty);
   native_context()->set_strict_mode_function_map(
       *strict_mode_function_map);
 
   // The final map for the strict mode functions. Writeable prototype.
   // This map is installed in MakeFunctionInstancePrototypeWritable.
-  strict_mode_function_instance_map_writable_prototype_ =
+  strict_mode_function_map_writable_prototype_ =
       CreateStrictModeFunctionMap(ADD_WRITEABLE_PROTOTYPE, empty);
 
   // Complete the callbacks.
-  PoisonArgumentsAndCaller(strict_mode_function_instance_map);
   PoisonArgumentsAndCaller(strict_mode_function_without_prototype_map);
   PoisonArgumentsAndCaller(strict_mode_function_map);
-  PoisonArgumentsAndCaller(
-      strict_mode_function_instance_map_writable_prototype_);
+  PoisonArgumentsAndCaller(strict_mode_function_map_writable_prototype_);
 }
 
 
 static void SetAccessors(Handle<Map> map,
                          Handle<String> name,
                          Handle<JSFunction> func) {
   DescriptorArray* descs = map->instance_descriptors();
   int number = descs->SearchWithCache(*name, *map);
   AccessorPair* accessors = AccessorPair::cast(descs->GetValue(number));
   accessors->set_getter(*func);
@@ skipping 1870 matching lines @@
   Handle<Map> new_to_map = factory->CopyMap(old_to_map);
   new_to_map->set_prototype(from->map()->prototype());
   to->set_map(*new_to_map);
 }
 
 
 void Genesis::MakeFunctionInstancePrototypeWritable() {
   // The maps with writable prototype are created in CreateEmptyFunction
   // and CreateStrictModeFunctionMaps respectively. Initially the maps are
   // created with read-only prototype for JS builtins processing.
-  ASSERT(!function_instance_map_writable_prototype_.is_null());
-  ASSERT(!strict_mode_function_instance_map_writable_prototype_.is_null());
+  ASSERT(!function_map_writable_prototype_.is_null());
+  ASSERT(!strict_mode_function_map_writable_prototype_.is_null());
 
   // Replace function instance maps to make prototype writable.
-  native_context()->set_function_map(
-    *function_instance_map_writable_prototype_);
+  native_context()->set_function_map(*function_map_writable_prototype_);
   native_context()->set_strict_mode_function_map(
-    *strict_mode_function_instance_map_writable_prototype_);
+      *strict_mode_function_map_writable_prototype_);
 }
 
 
 Genesis::Genesis(Isolate* isolate,
                  Handle<Object> global_object,
                  v8::Handle<v8::ObjectTemplate> global_template,
                  v8::ExtensionConfiguration* extensions)
     : isolate_(isolate),
       active_(isolate->bootstrapper()) {
   result_ = Handle<Context>::null();
@@ skipping 75 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   ASSERT(!IsActive());
 }
 
 } }  // namespace v8::internal