Consistently order receiver and holder argument in ElementAccessor.

src/elements.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 87 matching lines @@
 //   }
 //
 // This is an example of the Curiously Recurring Template Pattern (see
 // http://en.wikipedia.org/wiki/Curiously_recurring_template_pattern).  We use
 // CRTP to guarantee aggressive compile time optimizations (i.e.  inlining and
 // specialization of SomeElementsAccessor methods).
 template <typename ElementsAccessorSubclass, typename BackingStoreClass>
 class ElementsAccessorBase : public ElementsAccessor {
  protected:
   explicit ElementsAccessorBase(const char* name) : ElementsAccessor(name) { }
-  virtual MaybeObject* Get(FixedArrayBase* backing_store,
-                           uint32_t key,
-                           JSObject* obj,
-                           Object* receiver) {
-    return ElementsAccessorSubclass::GetImpl(
-        BackingStoreClass::cast(backing_store), key, obj, receiver);
+
+  static bool HasElementImpl(Object* receiver,
+                             JSObject* holder,
+                             uint32_t key,
+                             BackingStoreClass* backing_store) {
+    MaybeObject* element =
+        ElementsAccessorSubclass::GetImpl(receiver, holder, key, backing_store);
+    return !element->IsTheHole();
   }
 
-  static MaybeObject* GetImpl(BackingStoreClass* backing_store,
+  virtual bool HasElement(Object* receiver,
+                          JSObject* holder,
+                          uint32_t key,
+                          FixedArrayBase* backing_store) {
+    if (backing_store == NULL) {
+      backing_store = holder->elements();
+    }
+    return ElementsAccessorSubclass::HasElementImpl(
+        receiver, holder, key, BackingStoreClass::cast(backing_store));
+  }
+
+  virtual MaybeObject* Get(Object* receiver,
+                           JSObject* holder,
+                           uint32_t key,
+                           FixedArrayBase* backing_store) {
+    if (backing_store == NULL) {
+      backing_store = holder->elements();
+    }
+    return ElementsAccessorSubclass::GetImpl(
+        receiver, holder, key, BackingStoreClass::cast(backing_store));
+  }
+
+  static MaybeObject* GetImpl(Object* receiver,
+                              JSObject* obj,
                               uint32_t key,
-                              JSObject* obj,
-                              Object* receiver) {
+                              BackingStoreClass* backing_store) {
     return (key < ElementsAccessorSubclass::GetCapacityImpl(backing_store))
            ? backing_store->get(key)
            : backing_store->GetHeap()->the_hole_value();
   }
 
-  virtual MaybeObject* SetLength(JSObject* obj,
+  virtual MaybeObject* SetLength(JSArray* array,
                                  Object* length) {
-    ASSERT(obj->IsJSArray());
     return ElementsAccessorSubclass::SetLengthImpl(
-        BackingStoreClass::cast(obj->elements()), obj, length);
+        array, length, BackingStoreClass::cast(array->elements()));
   }
 
-  static MaybeObject* SetLengthImpl(BackingStoreClass* backing_store,
-                                    JSObject* obj,
-                                    Object* length);
+  static MaybeObject* SetLengthImpl(JSObject* obj,
+                                    Object* length,
+                                    BackingStoreClass* backing_store);
 
   virtual MaybeObject* SetCapacityAndLength(JSArray* array,
                                             int capacity,
                                             int length) {
     return ElementsAccessorSubclass::SetFastElementsCapacityAndLength(
         array,
         capacity,
         length);
   }
 
   static MaybeObject* SetFastElementsCapacityAndLength(JSObject* obj,
                                                        int capacity,
                                                        int length) {
     UNIMPLEMENTED();
     return obj;
   }
 
   virtual MaybeObject* Delete(JSObject* obj,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) = 0;
 
-  virtual MaybeObject* AddElementsToFixedArray(FixedArrayBase* from,
+  virtual MaybeObject* AddElementsToFixedArray(Object* receiver,
+                                               JSObject* holder,
                                                FixedArray* to,
-                                               JSObject* holder,
-                                               Object* receiver) {
+                                               FixedArrayBase* from) {
     int len0 = to->length();
 #ifdef DEBUG
     if (FLAG_enable_slow_asserts) {
       for (int i = 0; i < len0; i++) {
         ASSERT(!to->get(i)->IsTheHole());
       }
     }
 #endif
+    if (from == NULL) {
+      from = holder->elements();
+    }
     BackingStoreClass* backing_store = BackingStoreClass::cast(from);
     uint32_t len1 = ElementsAccessorSubclass::GetCapacityImpl(backing_store);
 
     // Optimize if 'other' is empty.
     // We cannot optimize if 'this' is empty, as other may have holes.
     if (len1 == 0) return to;
 
     // Compute how many elements are not in other.
     uint32_t extra = 0;
     for (uint32_t y = 0; y < len1; y++) {
       uint32_t key =
           ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, y);
       if (ElementsAccessorSubclass::HasElementImpl(
-              backing_store, key, holder, receiver)) {
+              receiver, holder, key, backing_store)) {
         MaybeObject* maybe_value =
-            ElementsAccessorSubclass::GetImpl(backing_store, key,
-                                              holder, receiver);
+            ElementsAccessorSubclass::GetImpl(receiver, holder,
+                                              key, backing_store);
         Object* value;
         if (!maybe_value->ToObject(&value)) return maybe_value;
         ASSERT(!value->IsTheHole());
         if (!HasKey(to, value)) {
           extra++;
         }
       }
     }
 
     if (extra == 0) return to;
@@ skipping 13 matching lines @@
         ASSERT(e->IsString() || e->IsNumber());
         result->set(i, e, mode);
       }
     }
     // Fill in the extra values.
     uint32_t index = 0;
     for (uint32_t y = 0; y < len1; y++) {
       uint32_t key =
           ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, y);
       if (ElementsAccessorSubclass::HasElementImpl(
-          backing_store, key, holder, receiver)) {
+              receiver, holder, key, backing_store)) {
         MaybeObject* maybe_value =
-            ElementsAccessorSubclass::GetImpl(backing_store, key,
-                                              holder, receiver);
+            ElementsAccessorSubclass::GetImpl(receiver, holder,
+                                              key, backing_store);
         Object* value;
         if (!maybe_value->ToObject(&value)) return maybe_value;
         if (!value->IsTheHole() && !HasKey(to, value)) {
           result->set(len0 + index, value);
           index++;
         }
       }
     }
     ASSERT(extra == index);
     return result;
   }
 
  protected:
   static uint32_t GetCapacityImpl(BackingStoreClass* backing_store) {
     return backing_store->length();
   }
 
   virtual uint32_t GetCapacity(FixedArrayBase* backing_store) {
     return ElementsAccessorSubclass::GetCapacityImpl(
         BackingStoreClass::cast(backing_store));
   }
 
-  static bool HasElementImpl(BackingStoreClass* backing_store,
-                             uint32_t key,
-                             JSObject* holder,
-                             Object* receiver) {
-    MaybeObject* element =
-        ElementsAccessorSubclass::GetImpl(backing_store, key, holder, receiver);
-    return !element->IsTheHole();
-  }
-
-  virtual bool HasElement(FixedArrayBase* backing_store,
-                          uint32_t key,
-                          JSObject* holder,
-                          Object* receiver) {
-    return ElementsAccessorSubclass::HasElementImpl(
-        BackingStoreClass::cast(backing_store), key, holder, receiver);
-  }
-
   static uint32_t GetKeyForIndexImpl(BackingStoreClass* backing_store,
                                      uint32_t index) {
     return index;
   }
 
   virtual uint32_t GetKeyForIndex(FixedArrayBase* backing_store,
                                   uint32_t index) {
     return ElementsAccessorSubclass::GetKeyForIndexImpl(
         BackingStoreClass::cast(backing_store), index);
   }
@@ skipping 176 matching lines @@
                               JSReceiver::DeleteMode mode) {
     int length = obj->IsJSArray()
         ? Smi::cast(JSArray::cast(obj)->length())->value()
         : FixedDoubleArray::cast(obj->elements())->length();
     if (key < static_cast<uint32_t>(length)) {
       FixedDoubleArray::cast(obj->elements())->set_the_hole(key);
     }
     return obj->GetHeap()->true_value();
   }
 
-  static bool HasElementImpl(FixedDoubleArray* backing_store,
+  static bool HasElementImpl(Object* receiver,
+                             JSObject* holder,
                              uint32_t key,
-                             JSObject* holder,
-                             Object* receiver) {
+                             FixedDoubleArray* backing_store) {
     return !backing_store->is_the_hole(key);
   }
 };
 
 
 // Super class for all external element arrays.
 template<typename ExternalElementsAccessorSubclass,
          typename ExternalArray>
 class ExternalElementsAccessor
     : public ElementsAccessorBase<ExternalElementsAccessorSubclass,
                                   ExternalArray> {
  public:
   explicit ExternalElementsAccessor(const char* name)
       : ElementsAccessorBase<ExternalElementsAccessorSubclass,
                              ExternalArray>(name) {}
 
  protected:
   friend class ElementsAccessorBase<ExternalElementsAccessorSubclass,
                                     ExternalArray>;
 
-  static MaybeObject* GetImpl(ExternalArray* backing_store,
+  static MaybeObject* GetImpl(Object* receiver,
+                              JSObject* obj,
                               uint32_t key,
-                              JSObject* obj,
-                              Object* receiver) {
+                              ExternalArray* backing_store) {
     return
         key < ExternalElementsAccessorSubclass::GetCapacityImpl(backing_store)
         ? backing_store->get(key)
         : backing_store->GetHeap()->undefined_value();
   }
 
-  static MaybeObject* SetLengthImpl(ExternalArray* backing_store,
-                                    JSObject* obj,
-                                    Object* length) {
+  static MaybeObject* SetLengthImpl(JSObject* obj,
+                                    Object* length,
+                                    ExternalArray* backing_store) {
     // External arrays do not support changing their length.
     UNREACHABLE();
     return obj;
   }
 
   virtual MaybeObject* Delete(JSObject* obj,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) {
     // External arrays always ignore deletes.
     return obj->GetHeap()->true_value();
   }
 
-  static bool HasElementImpl(ExternalArray* backing_store,
+  static bool HasElementImpl(Object* receiver,
+                             JSObject* holder,
                              uint32_t key,
-                             JSObject* holder,
-                             Object* receiver) {
+                             ExternalArray* backing_store) {
     uint32_t capacity =
         ExternalElementsAccessorSubclass::GetCapacityImpl(backing_store);
     return key < capacity;
   }
 };
 
 
 class ExternalByteElementsAccessor
     : public ExternalElementsAccessor<ExternalByteElementsAccessor,
                                       ExternalByteArray> {
@@ skipping 197 matching lines @@
  protected:
   friend class ElementsAccessorBase<DictionaryElementsAccessor,
                                     SeededNumberDictionary>;
 
   virtual MaybeObject* Delete(JSObject* obj,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) {
     return DeleteCommon(obj, key, mode);
   }
 
-  static MaybeObject* GetImpl(SeededNumberDictionary* backing_store,
+  static MaybeObject* GetImpl(Object* receiver,
+                              JSObject* obj,
                               uint32_t key,
-                              JSObject* obj,
-                              Object* receiver) {
+                              SeededNumberDictionary* backing_store) {
     int entry = backing_store->FindEntry(key);
     if (entry != SeededNumberDictionary::kNotFound) {
       Object* element = backing_store->ValueAt(entry);
       PropertyDetails details = backing_store->DetailsAt(entry);
       if (details.type() == CALLBACKS) {
         return obj->GetElementWithCallback(receiver,
                                            element,
                                            key,
                                            obj);
       } else {
         return element;
       }
     }
     return obj->GetHeap()->the_hole_value();
   }
 
-  static bool HasElementImpl(SeededNumberDictionary* backing_store,
+  static bool HasElementImpl(Object* receiver,
+                             JSObject* holder,
                              uint32_t key,
-                             JSObject* holder,
-                             Object* receiver) {
+                             SeededNumberDictionary* backing_store) {
     return backing_store->FindEntry(key) !=
         SeededNumberDictionary::kNotFound;
   }
 
   static uint32_t GetKeyForIndexImpl(SeededNumberDictionary* dict,
                                      uint32_t index) {
     Object* key = dict->KeyAt(index);
     return Smi::cast(key)->value();
   }
 };
 
 
 class NonStrictArgumentsElementsAccessor
     : public ElementsAccessorBase<NonStrictArgumentsElementsAccessor,
                                   FixedArray> {
  public:
   explicit NonStrictArgumentsElementsAccessor(const char* name)
       : ElementsAccessorBase<NonStrictArgumentsElementsAccessor,
                              FixedArray>(name) {}
  protected:
   friend class ElementsAccessorBase<NonStrictArgumentsElementsAccessor,
                                     FixedArray>;
 
-  static MaybeObject* GetImpl(FixedArray* parameter_map,
+  static MaybeObject* GetImpl(Object* receiver,
+                              JSObject* obj,
                               uint32_t key,
-                              JSObject* obj,
-                              Object* receiver) {
+                              FixedArray* parameter_map) {
     Object* probe = GetParameterMapArg(obj, parameter_map, key);
     if (!probe->IsTheHole()) {
       Context* context = Context::cast(parameter_map->get(0));
       int context_index = Smi::cast(probe)->value();
       ASSERT(!context->get(context_index)->IsTheHole());
       return context->get(context_index);
     } else {
       // Object is not mapped, defer to the arguments.
       FixedArray* arguments = FixedArray::cast(parameter_map->get(1));
       MaybeObject* maybe_result = ElementsAccessor::ForArray(arguments)->Get(
-          arguments, key, obj, receiver);
+          receiver, obj, key, arguments);
       Object* result;
       if (!maybe_result->ToObject(&result)) return maybe_result;
       // Elements of the arguments object in slow mode might be slow aliases.
       if (result->IsAliasedArgumentsEntry()) {
         AliasedArgumentsEntry* entry = AliasedArgumentsEntry::cast(result);
         Context* context = Context::cast(parameter_map->get(0));
         int context_index = entry->aliased_context_slot();
         ASSERT(!context->get(context_index)->IsTheHole());
         return context->get(context_index);
       } else {
         return result;
       }
     }
   }
 
-  static MaybeObject* SetLengthImpl(FixedArray* parameter_map,
-                                    JSObject* obj,
-                                    Object* length) {
+  static MaybeObject* SetLengthImpl(JSObject* obj,
+                                    Object* length,
+                                    FixedArray* parameter_map) {
     // TODO(mstarzinger): This was never implemented but will be used once we
     // correctly implement [[DefineOwnProperty]] on arrays.
     UNIMPLEMENTED();
     return obj;
   }
 
   virtual MaybeObject* Delete(JSObject* obj,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) {
     FixedArray* parameter_map = FixedArray::cast(obj->elements());
@@ skipping 18 matching lines @@
     FixedArrayBase* arguments = FixedArrayBase::cast(parameter_map->get(1));
     return Max(static_cast<uint32_t>(parameter_map->length() - 2),
                ForArray(arguments)->GetCapacity(arguments));
   }
 
   static uint32_t GetKeyForIndexImpl(FixedArray* dict,
                                      uint32_t index) {
     return index;
   }
 
-  static bool HasElementImpl(FixedArray* parameter_map,
+  static bool HasElementImpl(Object* receiver,
+                             JSObject* holder,
                              uint32_t key,
-                             JSObject* holder,
-                             Object* receiver) {
+                             FixedArray* parameter_map) {
     Object* probe = GetParameterMapArg(holder, parameter_map, key);
     if (!probe->IsTheHole()) {
       return true;
     } else {
       FixedArrayBase* arguments = FixedArrayBase::cast(parameter_map->get(1));
       ElementsAccessor* accessor = ElementsAccessor::ForArray(arguments);
-      return !accessor->Get(arguments, key, holder, receiver)->IsTheHole();
+      return !accessor->Get(receiver, holder, key, arguments)->IsTheHole();
     }
   }
 
  private:
   static Object* GetParameterMapArg(JSObject* holder,
                                     FixedArray* parameter_map,
                                     uint32_t key) {
     uint32_t length = holder->IsJSArray()
         ? Smi::cast(JSArray::cast(holder)->length())->value()
         : parameter_map->length();
@@ skipping 79 matching lines @@
 
   STATIC_ASSERT((sizeof(accessor_array) / sizeof(*accessor_array)) ==
                 kElementsKindCount);
 
   elements_accessors_ = accessor_array;
 }
 
 
 template <typename ElementsAccessorSubclass, typename BackingStoreClass>
 MaybeObject* ElementsAccessorBase<ElementsAccessorSubclass, BackingStoreClass>::
-    SetLengthImpl(BackingStoreClass* backing_store,
-                  JSObject* obj,
-                  Object* length) {
+    SetLengthImpl(JSObject* obj,
+                  Object* length,
+                  BackingStoreClass* backing_store) {
   JSArray* array = JSArray::cast(obj);
 
   // Fast case: The new length fits into a Smi.
   MaybeObject* maybe_smi_length = length->ToSmi();
   Object* smi_length = Smi::FromInt(0);
   if (maybe_smi_length->ToObject(&smi_length) && smi_length->IsSmi()) {
     const int value = Smi::cast(smi_length)->value();
     if (value >= 0) {
       Object* new_length;
       MaybeObject* result = ElementsAccessorSubclass::
@@ skipping 36 matching lines @@
   if (!maybe_obj->To(&new_backing_store)) return maybe_obj;
   new_backing_store->set(0, length);
   { MaybeObject* result = array->SetContent(new_backing_store);
     if (result->IsFailure()) return result;
   }
   return array;
 }
 
 
 } }  // namespace v8::internal