LibJS: Make NativeProperty a plain Cell instead of an Object

This removes the need for NativeProperty objects to have a prototype,
which just made things confusing.

Libraries/LibJS/Forward.h

@@ -89,6 +89,7 @@ class HeapBlock;
 class Interpreter;
 class LexicalEnvironment;
 class MarkedValueList;
+class NativeProperty;
 class PrimitiveString;
 class Reference;
 class ScopeNode;

Libraries/LibJS/Runtime/NativeProperty.cpp

@@ -29,9 +29,8 @@
 
 namespace JS {
 
-NativeProperty::NativeProperty(GlobalObject& global_object, AK::Function<Value(Interpreter&, GlobalObject&)> getter, AK::Function<void(Interpreter&, GlobalObject&, Value)> setter)
-    : Object(Object::ConstructWithoutPrototypeTag::Tag, global_object)
-    , m_getter(move(getter))
+NativeProperty::NativeProperty(AK::Function<Value(Interpreter&, GlobalObject&)> getter, AK::Function<void(Interpreter&, GlobalObject&, Value)> setter)
+    : m_getter(move(getter))
     , m_setter(move(setter))
 {
 }

Libraries/LibJS/Runtime/NativeProperty.h

@@ -31,18 +31,16 @@
 
 namespace JS {
 
-class NativeProperty final : public Object {
-    JS_OBJECT(NativeProperty, Object);
-
+class NativeProperty final : public Cell {
 public:
-    NativeProperty(GlobalObject&, AK::Function<Value(Interpreter&, GlobalObject&)> getter, AK::Function<void(Interpreter&, GlobalObject&, Value)> setter);
+    NativeProperty(AK::Function<Value(Interpreter&, GlobalObject&)> getter, AK::Function<void(Interpreter&, GlobalObject&, Value)> setter);
     virtual ~NativeProperty() override;
 
     Value get(Interpreter&, GlobalObject&) const;
     void set(Interpreter&, GlobalObject&, Value);
 
 private:
-    virtual bool is_native_property() const override { return true; }
+    virtual const char* class_name() const override { return "NativeProperty"; }
 
     AK::Function<Value(Interpreter&, GlobalObject&)> m_getter;
     AK::Function<void(Interpreter&, GlobalObject&, Value)> m_setter;

Libraries/LibJS/Runtime/Object.cpp

@@ -171,7 +171,7 @@ Value Object::get_own_property(const Object& this_object, PropertyName property_
     if (value_here.is_accessor()) {
         return value_here.as_accessor().call_getter(Value(const_cast<Object*>(this)));
     }
-    if (value_here.is_object() && value_here.as_object().is_native_property())
+    if (value_here.is_native_property())
         return call_native_property_getter(const_cast<Object*>(&this_object), value_here);
     return value_here;
 }
@@ -282,7 +282,7 @@ Optional<PropertyDescriptor> Object::get_own_property_descriptor(PropertyName pr
     }
 
     PropertyDescriptor descriptor { attributes, {}, nullptr, nullptr };
-    if (value.is_object() && value.as_object().is_native_property()) {
+    if (value.is_native_property()) {
         auto result = call_native_property_getter(const_cast<Object*>(this), value);
         descriptor.value = result.value_or(js_undefined());
     } else if (value.is_accessor()) {
@@ -492,7 +492,7 @@ bool Object::put_own_property(Object& this_object, const FlyString& property_nam
     if (value.is_empty())
         return true;
 
-    if (value_here.is_object() && value_here.as_object().is_native_property()) {
+    if (value_here.is_native_property()) {
         call_native_property_setter(const_cast<Object*>(&this_object), value_here, value);
     } else {
         m_storage[metadata.value().offset] = value;
@@ -539,7 +539,7 @@ bool Object::put_own_property_by_index(Object& this_object, u32 property_index,
     if (value.is_empty())
         return true;
 
-    if (value_here.is_object() && value_here.as_object().is_native_property()) {
+    if (value_here.is_native_property()) {
         call_native_property_setter(const_cast<Object*>(&this_object), value_here, value);
     } else {
         m_indexed_properties.put(&this_object, property_index, value, attributes, mode == PutOwnPropertyMode::Put);
@@ -643,7 +643,7 @@ bool Object::put_by_index(u32 property_index, Value value)
                 value_here.value.as_accessor().call_setter(object, value);
                 return true;
             }
-            if (value_here.value.is_object() && value_here.value.as_object().is_native_property()) {
+            if (value_here.value.is_native_property()) {
                 call_native_property_setter(const_cast<Object*>(this), value_here.value, value);
                 return true;
             }
@@ -678,7 +678,7 @@ bool Object::put(PropertyName property_name, Value value)
                 value_here.as_accessor().call_setter(Value(this), value);
                 return true;
             }
-            if (value_here.is_object() && value_here.as_object().is_native_property()) {
+            if (value_here.is_native_property()) {
                 call_native_property_setter(const_cast<Object*>(this), value_here, value);
                 return true;
             }
@@ -704,7 +704,7 @@ bool Object::define_native_function(const FlyString& property_name, AK::Function
 
 bool Object::define_native_property(const FlyString& property_name, AK::Function<Value(Interpreter&, GlobalObject&)> getter, AK::Function<void(Interpreter&, GlobalObject&, Value)> setter, PropertyAttributes attribute)
 {
-    return define_property(property_name, heap().allocate<NativeProperty>(global_object(), global_object(), move(getter), move(setter)), attribute);
+    return define_property(property_name, heap().allocate<NativeProperty>(global_object(), move(getter), move(setter)), attribute);
 }
 
 void Object::visit_children(Cell::Visitor& visitor)
@@ -809,24 +809,20 @@ Value Object::invoke(const FlyString& property_name, Optional<MarkedValueList> a
 
 Value Object::call_native_property_getter(Object* this_object, Value property) const
 {
-    ASSERT(property.is_object());
-    ASSERT(property.as_object().is_native_property());
-    auto& native_property = static_cast<NativeProperty&>(property.as_object());
+    ASSERT(property.is_native_property());
     auto& call_frame = interpreter().push_call_frame();
     call_frame.this_value = this_object;
-    auto result = native_property.get(interpreter(), global_object());
+    auto result = property.as_native_property().get(interpreter(), global_object());
     interpreter().pop_call_frame();
     return result;
 }
 
 void Object::call_native_property_setter(Object* this_object, Value property, Value value) const
 {
-    ASSERT(property.is_object());
-    ASSERT(property.as_object().is_native_property());
-    auto& native_property = static_cast<NativeProperty&>(property.as_object());
+    ASSERT(property.is_native_property());
     auto& call_frame = interpreter().push_call_frame();
     call_frame.this_value = this_object;
-    native_property.set(interpreter(), global_object(), value);
+    property.as_native_property().set(interpreter(), global_object(), value);
     interpreter().pop_call_frame();
 }
 

Libraries/LibJS/Runtime/Object.h

@@ -110,7 +110,6 @@ public:
     virtual bool is_function() const { return false; }
     virtual bool is_native_function() const { return false; }
     virtual bool is_bound_function() const { return false; }
-    virtual bool is_native_property() const { return false; }
     virtual bool is_proxy_object() const { return false; }
     virtual bool is_regexp_object() const { return false; }
     virtual bool is_boolean_object() const { return false; }

Libraries/LibJS/Runtime/Value.h

@@ -51,6 +51,7 @@ public:
         Symbol,
         Accessor,
         BigInt,
+        NativeProperty,
     };
 
     enum class PreferredType {
@@ -69,7 +70,8 @@ public:
     bool is_symbol() const { return m_type == Type::Symbol; }
     bool is_accessor() const { return m_type == Type::Accessor; };
     bool is_bigint() const { return m_type == Type::BigInt; };
-    bool is_cell() const { return is_string() || is_accessor() || is_object() || is_bigint() || is_symbol(); }
+    bool is_native_property() const { return m_type == Type::NativeProperty; }
+    bool is_cell() const { return is_string() || is_accessor() || is_object() || is_bigint() || is_symbol() || is_native_property(); }
     bool is_array() const;
     bool is_function() const;
 
@@ -147,6 +149,12 @@ public:
         m_value.as_bigint = bigint;
     }
 
+    Value(NativeProperty* native_property)
+        : m_type(Type::NativeProperty)
+    {
+        m_value.as_native_property = native_property;
+    }
+
     explicit Value(Type type)
         : m_type(type)
     {
@@ -220,6 +228,12 @@ public:
         return *m_value.as_bigint;
     }
 
+    NativeProperty& as_native_property()
+    {
+        ASSERT(is_native_property());
+        return *m_value.as_native_property;
+    }
+
     Array& as_array();
     Function& as_function();
 
@@ -259,6 +273,7 @@ private:
         Cell* as_cell;
         Accessor* as_accessor;
         BigInt* as_bigint;
+        NativeProperty* as_native_property;
     } m_value;
 };