Introduce a PrototypeIterator template and use it all over the place

src/accessors.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/compiler.h"
 #include "src/contexts.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
 #include "src/factory.h"
 #include "src/frames-inl.h"
 #include "src/isolate.h"
 #include "src/list-inl.h"
 #include "src/property-details.h"
+#include "src/prototype-iterator.h"
 
 namespace v8 {
 namespace internal {
 
 
 // We have a slight impedance mismatch between the external API and the way we
 // use callbacks internally: Externally, callbacks can only be used with
 // v8::Object, but internally we even have callbacks on entities which are
 // higher in the hierarchy, so we can only return i::Object here, not
 // i::JSObject.
@@ skipping 32 matching lines @@
   info->set_expected_receiver_type(accessor->expected_receiver_type());
   info->set_getter(accessor->getter());
   info->set_setter(accessor->setter());
   info->set_data(accessor->data());
   return info;
 }
 
 
 template <class C>
 static C* FindInstanceOf(Isolate* isolate, Object* obj) {
-  for (Object* cur = obj; !cur->IsNull(); cur = cur->GetPrototype(isolate)) {
-    if (Is<C>(cur)) return C::cast(cur);
+  for (PrototypeIterator<STORE_AS_POINTER, TYPE_BASED_WALK, END_AT_NULL_VALUE>
+           iter(isolate, obj); !iter.IsAtEnd(); iter.Advance()) {
+    if (Is<C>(iter.GetCurrent())) return C::cast(iter.GetCurrent());
   }
   return NULL;
 }
 
 
 static V8_INLINE bool CheckForName(Handle<String> name,
                                    Handle<String> property_name,
                                    int offset,
                                    int* object_offset) {
   if (String::Equals(name, property_name)) {
@@ skipping 685 matching lines @@
 //
 
 static Handle<Object> GetFunctionPrototype(Isolate* isolate,
                                            Handle<Object> receiver) {
   Handle<JSFunction> function;
   {
     DisallowHeapAllocation no_allocation;
     JSFunction* function_raw = FindInstanceOf<JSFunction>(isolate, *receiver);
     if (function_raw == NULL) return isolate->factory()->undefined_value();
     while (!function_raw->should_have_prototype()) {
-      function_raw = FindInstanceOf<JSFunction>(isolate,
-                                                function_raw->GetPrototype());
+      function_raw = FindInstanceOf<JSFunction>(
+          isolate, SAFE_GET_PROTOTYPE_FAST(function_raw));
       // There has to be one because we hit the getter.
       ASSERT(function_raw != NULL);
     }
     function = Handle<JSFunction>(function_raw, isolate);
   }
 
   if (!function->has_prototype()) {
     Handle<Object> proto = isolate->factory()->NewFunctionPrototype(function);
     JSFunction::SetPrototype(function, proto);
   }
@@ skipping 563 matching lines @@
   info->set_data(Smi::FromInt(index));
   Handle<Object> getter = v8::FromCData(isolate, &ModuleGetExport);
   Handle<Object> setter = v8::FromCData(isolate, &ModuleSetExport);
   info->set_getter(*getter);
   if (!(attributes & ReadOnly)) info->set_setter(*setter);
   return info;
 }
 
 
 } }  // namespace v8::internal