new style of property/function callbacks

src/arguments.h

 // 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 64 matching lines @@
   int length() const { return length_; }
 
   Object** arguments() { return arguments_; }
 
  private:
   int length_;
   Object** arguments_;
 };
 
 
+#define FOR_EACH_CALLBACK_TABLE_MAPPING(F) \
+  F(AccessorGetter, AccessorGetterCallback) \
+  F(AccessorSetter, AccessorSetterCallback) \
+  F(InvocationCallback, FunctionCallback) \
+  F(NamedPropertySetter, NamedPropertySetterCallback) \
+  F(NamedPropertyQuery, NamedPropertyQueryCallback) \
+  F(NamedPropertyDeleter, NamedPropertyDeleterCallback) \
+  F(IndexedPropertyGetter, IndexedPropertyGetterCallback) \
+  F(IndexedPropertySetter, IndexedPropertySetterCallback) \
+  F(IndexedPropertyQuery, IndexedPropertyQueryCallback) \
+  F(IndexedPropertyDeleter, IndexedPropertyDeleterCallback) \
+  F(IndexedPropertyEnumerator, IndexedPropertyEnumeratorCallback) \
+
+// These aren't included in the list as they have duplicate signatures
+// F(NamedPropertyEnumerator, NamedPropertyEnumeratorCallback) \
+// F(NamedPropertyGetter, NamedPropertyGetterCallback) \
+
+// TODO(dcarney): Remove this class when old callbacks are gone.
+class CallbackTable {
+ public:
+  // TODO(dcarney): Flip this when it makes sense for performance.
+  static const bool kStoreVoidFunctions = true;
+  static inline bool ReturnsVoid(Isolate* isolate, void* function) {
+    CallbackTable* table = isolate->callback_table();
+    bool contains =
+        table != NULL &&
+        table->map_.occupancy() != 0 &&
+        table->Contains(function);
+    return contains == kStoreVoidFunctions;
+  }
+
+#define WRITE_REGISTER(OldFunction, NewFunction)                    \
+  static OldFunction Register(Isolate* isolate, NewFunction f) {    \
+    InsertCallback(isolate, reinterpret_cast<void*>(f), true);      \
+    return reinterpret_cast<OldFunction>(f);                        \
+  }                                                                 \
+                                                                    \
+  static OldFunction Register(Isolate* isolate, OldFunction f) {    \
+    InsertCallback(isolate, reinterpret_cast<void*>(f), false);     \
+    return f;                                                       \
+  }
+  FOR_EACH_CALLBACK_TABLE_MAPPING(WRITE_REGISTER)
+#undef WRITE_REGISTER
+
+ private:
+  CallbackTable(): map_(Match, 64) {}
+  typedef HashMap::Entry Entry;
+  static bool Match(void* a, void* b) {
+    return a == b;
+  }
+  static uint32_t Hash(void* function) {
+    uintptr_t as_int = reinterpret_cast<uintptr_t>(function);
+    if (sizeof(function) == 4) return static_cast<uint32_t>(as_int);
+    uint64_t as_64 = static_cast<uint64_t>(as_int);
+    return
+        static_cast<uint32_t>(as_64 >> 32) ^
+        static_cast<uint32_t>(as_64);
+  }
+  bool Contains(void* function) {
+    ASSERT(function != NULL);
+    return map_.Lookup(function, Hash(function), false) != NULL;
+  }
+  static void InsertCallback(Isolate* isolate,
+                             void* function,
+                             bool returns_void) {
+    if (function == NULL) return;
+    // Don't store for performance.
+    if (kStoreVoidFunctions != returns_void) return;
+    CallbackTable* table = isolate->callback_table();
+    if (table == NULL) {
+      table = new CallbackTable();
+      isolate->set_callback_table(table);
+    }
+    table->Insert(function);
+  }
+  void Insert(void* function) {
+    ASSERT(function != NULL);
+    Entry* entry = map_.Lookup(function, Hash(function), true);
+    ASSERT(entry != NULL);
+    ASSERT(entry->value == NULL || entry->value == function);
+    entry->value = function;
+  }
+  HashMap map_;
+  DISALLOW_COPY_AND_ASSIGN(CallbackTable);
+};
+
+
 // Custom arguments replicate a small segment of stack that can be
 // accessed through an Arguments object the same way the actual stack
 // can.
-class CustomArguments : public Relocatable {
- public:
-  inline CustomArguments(Isolate* isolate,
-                         Object* data,
-                         Object* self,
-                         JSObject* holder) : Relocatable(isolate) {
-    ASSERT(reinterpret_cast<Object*>(isolate)->IsSmi());
-    values_[3] = self;
-    values_[2] = holder;
-    values_[1] = data;
-    values_[0] = reinterpret_cast<Object*>(isolate);
-  }
-
-  inline explicit CustomArguments(Isolate* isolate) : Relocatable(isolate) {
-#ifdef DEBUG
-    for (size_t i = 0; i < ARRAY_SIZE(values_); i++) {
-      values_[i] = reinterpret_cast<Object*>(kZapValue);
+template<int kArrayLength>
+class CustomArgumentsBase : public Relocatable {
+ public:
+  virtual inline void IterateInstance(ObjectVisitor* v) {
+    v->VisitPointers(values_, values_ + kArrayLength);
+  }
+ protected:
+  inline Object** end() { return values_ + kArrayLength - 1; }
+  explicit inline CustomArgumentsBase(Isolate* isolate)
+      : Relocatable(isolate) {}
+  Object* values_[kArrayLength];
+};
+
+
+template<typename T>
+class CustomArguments : public CustomArgumentsBase<T::kArgsLength> {
+ public:
+  static const int kReturnValueOffset = T::kReturnValueIndex;
+
+  typedef CustomArgumentsBase<T::kArgsLength> Super;
+  ~CustomArguments() {
+    // TODO(dcarney): create a new zap value for this.
+    this->end()[kReturnValueOffset] =
+        reinterpret_cast<Object*>(kHandleZapValue);
+  }
+
+#define WRITE_CALLBACK_RESULT(OldFunction, NewFunction)               \
+  template<typename V>                                                \
+  inline v8::Handle<V> GetCallbackResult(Isolate* isolate,            \
+                                         OldFunction function,        \
+                                         v8::Handle<V> call_result) { \
+    return GetCallbackResult(isolate,                                 \
+                          reinterpret_cast<void*>(function),          \
+                          call_result);                               \
+  }
+  FOR_EACH_CALLBACK_TABLE_MAPPING(WRITE_CALLBACK_RESULT)
+#undef WRITE_CALLBACK_RESULT
+
+ protected:
+  template<typename V>
+  inline v8::Handle<V> GetCallbackResult(Isolate* isolate,
+                                         void* function,
+                                         v8::Handle<V> call_result) {
+    // For non-void calls, return the result only if call_result is set.
+    if (!CallbackTable::ReturnsVoid(isolate, function) &&
+        !call_result.IsEmpty()) {
+      return call_result;
     }
-#endif
-  }
-
-  void IterateInstance(ObjectVisitor* v);
-  Object** end() { return values_ + ARRAY_SIZE(values_) - 1; }
-
- private:
-  Object* values_[4];
-};
-
-
+    // Check the ReturnValue.
+    Object* object = this->end()[kReturnValueOffset];
+    // Nothing was set, return empty handle as per previous behaviour.
+    if (object->IsTheHole()) return v8::Handle<V>();
+    // We shouldn't need this, but play it safe for now.
+    // TODO(dcarney) Remove once all calls to this are verified as safe??
+    return v8::Local<V>::New(reinterpret_cast<v8::Isolate*>(isolate),
+                             v8::Handle<V>(reinterpret_cast<V*>(&object)));
+  }
+
+  explicit inline CustomArguments(Isolate* isolate) : Super(isolate) {}
+};
+
+
+class PropertyCallbackArguments
+    : public CustomArguments<PropertyCallbackInfo<Value> > {
+ public:
+  typedef PropertyCallbackInfo<Value> T;
+  typedef CustomArguments<T> Super;
+  static const int kArgsLength = T::kArgsLength;
+  static const int kThisIndex = T::kThisIndex;
+  static const int kHolderIndex = T::kHolderIndex;
+
+  PropertyCallbackArguments(Isolate* isolate,
+                            Object* data,
+                            Object* self,
+                            JSObject* holder)
+      : Super(isolate) {
+    Object** values = this->end();
+    values[T::kThisIndex] = self;
+    values[T::kHolderIndex] = holder;
+    values[T::kDataIndex] = data;
+    values[T::kIsolateIndex] = reinterpret_cast<Object*>(isolate);
+    values[T::kReturnValueIndex] = isolate->heap()->the_hole_value();
+    ASSERT(values[T::kHolderIndex]->IsHeapObject());
+    ASSERT(values[T::kIsolateIndex]->IsSmi());
+  }
+
+  inline v8::AccessorInfo NewInfo() {
+    return v8::AccessorInfo(end());
+  }
+};
+
+
+class FunctionCallbackArguments
+    : public CustomArguments<FunctionCallbackInfo<Value> > {
+ public:
+  typedef FunctionCallbackInfo<Value> T;
+  typedef CustomArguments<T> Super;
+  static const int kArgsLength = T::kArgsLength;
+
+  FunctionCallbackArguments(internal::Isolate* isolate,
+      internal::Object* data,
+      internal::JSFunction* callee,
+      internal::Object* holder)
+        : Super(isolate) {
+    Object** values = end();
+    values[T::kDataIndex] = data;
+    values[T::kCalleeIndex] = callee;
+    values[T::kHolderIndex] = holder;
+    values[T::kIsolateIndex] = reinterpret_cast<internal::Object*>(isolate);
+    values[T::kReturnValueIndex] = isolate->heap()->the_hole_value();
+    ASSERT(values[T::kCalleeIndex]->IsJSFunction());
+    ASSERT(values[T::kHolderIndex]->IsHeapObject());
+    ASSERT(values[T::kIsolateIndex]->IsSmi());
+  }
+
+  inline v8::Arguments NewArguments(internal::Object** argv,
+                                    int argc,
+                                    bool is_construct_call) {
+    return v8::Arguments(this->end(), argv, argc, is_construct_call);
+  }
+};
+
+
 #define DECLARE_RUNTIME_FUNCTION(Type, Name)    \
 Type Name(Arguments args, Isolate* isolate)
 
 
 #define RUNTIME_FUNCTION(Type, Name)            \
 Type Name(Arguments args, Isolate* isolate)
 
 
 #define RUNTIME_ARGUMENTS(isolate, args) args, isolate
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARGUMENTS_H_