LibJS+LibWeb: Move native properties to separate getters/setters

This was a bit cumbersome now, but it gets us closer to a format suited
for code generation.

Libraries/LibJS/Runtime/Array.cpp

@@ -27,20 +27,14 @@
 #include <AK/Function.h>
 #include <LibJS/Interpreter.h>
 #include <LibJS/Runtime/Array.h>
+#include <LibJS/Runtime/Error.h>
 
 namespace JS {
 
 Array::Array()
 {
     set_prototype(interpreter().array_prototype());
-    put_native_property(
-        "length",
-        [this](Object*) {
-            return Value(length());
-        },
-        [](Object*, Value) {
-            ASSERT_NOT_REACHED();
-        });
+    put_native_property("length", length_getter, length_setter);
 }
 
 Array::~Array()
@@ -96,4 +90,20 @@ bool Array::put_own_property(Object& this_object, const FlyString& property_name
     }
     return Object::put_own_property(this_object, property_name, value);
 }
+
+Value Array::length_getter(Interpreter& interpreter)
+{
+    auto* this_object = interpreter.this_value().to_object(interpreter.heap());
+    if (!this_object)
+        return {};
+    if (!this_object->is_array())
+        return interpreter.throw_exception<Error>("TypeError", "Not an array");
+    return Value(static_cast<const Array*>(this_object)->length());
+}
+
+void Array::length_setter(Interpreter&, Value)
+{
+    ASSERT_NOT_REACHED();
+}
+
 }

Libraries/LibJS/Runtime/Array.h

@@ -50,6 +50,9 @@ private:
     virtual Optional<Value> get_own_property(const Object& this_object, const FlyString& property_name) const override;
     virtual bool put_own_property(Object& this_object, const FlyString& property_name, Value) override;
 
+    static Value length_getter(Interpreter&);
+    static void length_setter(Interpreter&, Value);
+
     Vector<Value> m_elements;
 };
 

Libraries/LibJS/Runtime/ErrorPrototype.cpp

@@ -36,25 +36,32 @@ namespace JS {
 
 ErrorPrototype::ErrorPrototype()
 {
-    put_native_property(
-        "name", [](Object* this_object) {
-            ASSERT(this_object);
-            ASSERT(this_object->is_error());
-            return js_string(this_object->heap(), static_cast<const Error*>(this_object)->name());
-        },
-        nullptr);
-
-    put_native_property(
-        "message", [](Object* this_object) {
-            ASSERT(this_object);
-            ASSERT(this_object->is_error());
-            return js_string(this_object->heap(), static_cast<const Error*>(this_object)->message());
-        },
-        nullptr);
+    put_native_property("name", name_getter, nullptr);
+    put_native_property("message", message_getter, nullptr);
 }
 
 ErrorPrototype::~ErrorPrototype()
 {
 }
 
+Value ErrorPrototype::name_getter(Interpreter& interpreter)
+{
+    auto* this_object = interpreter.this_value().to_object(interpreter.heap());
+    if (!this_object)
+        return {};
+    if (!this_object->is_error())
+        return interpreter.throw_exception<Error>("TypeError", "Not an Error object");
+    return js_string(interpreter.heap(), static_cast<const Error*>(this_object)->name());
+}
+
+Value ErrorPrototype::message_getter(Interpreter& interpreter)
+{
+    auto* this_object = interpreter.this_value().to_object(interpreter.heap());
+    if (!this_object)
+        return {};
+    if (!this_object->is_error())
+        return interpreter.throw_exception<Error>("TypeError", "Not an Error object");
+    return js_string(interpreter.heap(), static_cast<const Error*>(this_object)->message());
+}
+
 }

Libraries/LibJS/Runtime/ErrorPrototype.h

@@ -37,6 +37,9 @@ public:
 
 private:
     virtual const char* class_name() const override { return "ErrorPrototype"; }
+
+    static Value name_getter(Interpreter&);
+    static Value message_getter(Interpreter&);
 };
 
 }

Libraries/LibJS/Runtime/NativeProperty.cpp

@@ -29,7 +29,7 @@
 
 namespace JS {
 
-NativeProperty::NativeProperty(AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter)
+NativeProperty::NativeProperty(AK::Function<Value(Interpreter&)> getter, AK::Function<void(Interpreter&, Value)> setter)
     : m_getter(move(getter))
     , m_setter(move(setter))
 {
@@ -39,18 +39,18 @@ NativeProperty::~NativeProperty()
 {
 }
 
-Value NativeProperty::get(Object* object) const
+Value NativeProperty::get(Interpreter& interpreter) const
 {
     if (!m_getter)
         return js_undefined();
-    return m_getter(object);
+    return m_getter(interpreter);
 }
 
-void NativeProperty::set(Object* object, Value value)
+void NativeProperty::set(Interpreter& interpreter, Value value)
 {
     if (!m_setter)
         return;
-    m_setter(object, move(value));
+    m_setter(interpreter, move(value));
 }
 
 }

Libraries/LibJS/Runtime/NativeProperty.h

@@ -33,18 +33,18 @@ namespace JS {
 
 class NativeProperty final : public Object {
 public:
-    NativeProperty(AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter);
+    NativeProperty(AK::Function<Value(Interpreter&)> getter, AK::Function<void(Interpreter&, Value)> setter);
     virtual ~NativeProperty() override;
 
-    Value get(Object*) const;
-    void set(Object*, Value);
+    Value get(Interpreter&) const;
+    void set(Interpreter&, Value);
 
 private:
     virtual bool is_native_property() const override { return true; }
     virtual const char* class_name() const override { return "NativeProperty"; }
 
-    AK::Function<Value(Object*)> m_getter;
-    AK::Function<void(Object*, Value)> m_setter;
+    AK::Function<Value(Interpreter&)> m_getter;
+    AK::Function<void(Interpreter&, Value)> m_setter;
 };
 
 }

Libraries/LibJS/Runtime/Object.cpp

@@ -56,8 +56,15 @@ bool Object::has_prototype(const Object* prototype) const
 Optional<Value> Object::get_own_property(const Object& this_object, const FlyString& property_name) const
 {
     auto value_here = m_properties.get(property_name);
-    if (value_here.has_value() && value_here.value().is_object() && value_here.value().as_object()->is_native_property())
-        return static_cast<NativeProperty*>(value_here.value().as_object())->get(&const_cast<Object&>(this_object));
+    if (value_here.has_value() && value_here.value().is_object() && value_here.value().as_object()->is_native_property()) {
+        auto& native_property = static_cast<const NativeProperty&>(*value_here.value().as_object());
+        auto& interpreter = const_cast<Object*>(this)->interpreter();
+        auto& call_frame = interpreter.push_call_frame();
+        call_frame.this_value = const_cast<Object*>(&this_object);
+        auto result = native_property.get(interpreter);
+        interpreter.pop_call_frame();
+        return result;
+    }
     return value_here;
 }
 
@@ -65,7 +72,13 @@ bool Object::put_own_property(Object& this_object, const FlyString& property_nam
 {
     auto value_here = m_properties.get(property_name);
     if (value_here.has_value() && value_here.value().is_object() && value_here.value().as_object()->is_native_property()) {
-        static_cast<NativeProperty*>(value_here.value().as_object())->set(&this_object, value);
+        auto& native_property = static_cast<NativeProperty&>(*value_here.value().as_object());
+        auto& interpreter = const_cast<Object*>(this)->interpreter();
+        auto& call_frame = interpreter.push_call_frame();
+        call_frame.this_value = &this_object;
+        dbg() << "put_own_property: " << &this_object << " . " << property_name << " = " << value;
+        native_property.set(interpreter, value);
+        interpreter.pop_call_frame();
     } else {
         m_properties.set(property_name, value);
     }
@@ -91,7 +104,12 @@ void Object::put(const FlyString& property_name, Value value)
         auto value_here = object->m_properties.get(property_name);
         if (value_here.has_value()) {
             if (value_here.value().is_object() && value_here.value().as_object()->is_native_property()) {
-                static_cast<NativeProperty*>(value_here.value().as_object())->set(const_cast<Object*>(this), value);
+                auto& native_property = static_cast<NativeProperty&>(*value_here.value().as_object());
+                auto& interpreter = const_cast<Object*>(this)->interpreter();
+                auto& call_frame = interpreter.push_call_frame();
+                call_frame.this_value = this;
+                native_property.set(interpreter, value);
+                interpreter.pop_call_frame();
                 return;
             }
             if (object->put_own_property(*this, property_name, value))
@@ -107,7 +125,7 @@ void Object::put_native_function(const FlyString& property_name, AK::Function<Va
     put(property_name, heap().allocate<NativeFunction>(move(native_function)));
 }
 
-void Object::put_native_property(const FlyString& property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter)
+void Object::put_native_property(const FlyString& property_name, AK::Function<Value(Interpreter&)> getter, AK::Function<void(Interpreter&, Value)> setter)
 {
     put(property_name, heap().allocate<NativeProperty>(move(getter), move(setter)));
 }

Libraries/LibJS/Runtime/Object.h

@@ -47,7 +47,7 @@ public:
     virtual bool put_own_property(Object& this_object, const FlyString& property_name, Value);
 
     void put_native_function(const FlyString& property_name, AK::Function<Value(Interpreter&)>);
-    void put_native_property(const FlyString& property_name, AK::Function<Value(Object*)> getter, AK::Function<void(Object*, Value)> setter);
+    void put_native_property(const FlyString& property_name, AK::Function<Value(Interpreter&)> getter, AK::Function<void(Interpreter&, Value)> setter);
 
     virtual bool is_error() const { return false; }
     virtual bool is_array() const { return false; }

Libraries/LibJS/Runtime/StringPrototype.cpp

@@ -28,6 +28,7 @@
 #include <AK/StringBuilder.h>
 #include <LibJS/Heap/Heap.h>
 #include <LibJS/Interpreter.h>
+#include <LibJS/Runtime/Error.h>
 #include <LibJS/Runtime/PrimitiveString.h>
 #include <LibJS/Runtime/StringObject.h>
 #include <LibJS/Runtime/StringPrototype.h>
@@ -37,13 +38,7 @@ namespace JS {
 
 StringPrototype::StringPrototype()
 {
-    put_native_property(
-        "length", [](Object* this_object) {
-            ASSERT(this_object);
-            ASSERT(this_object->is_string_object());
-            return Value((i32) static_cast<const StringObject*>(this_object)->primitive_string()->string().length());
-        },
-        nullptr);
+    put_native_property("length", length_getter, nullptr);
     put_native_function("charAt", char_at);
     put_native_function("repeat", repeat);
 }
@@ -88,4 +83,14 @@ Value StringPrototype::repeat(Interpreter& interpreter)
     return js_string(interpreter.heap(), builder.to_string());
 }
 
+Value StringPrototype::length_getter(Interpreter& interpreter)
+{
+    auto* this_object = interpreter.this_value().to_object(interpreter.heap());
+    if (!this_object)
+        return {};
+    if (!this_object->is_string_object())
+        return interpreter.throw_exception<Error>("TypeError", "Not a String object");
+    return Value((i32) static_cast<const StringObject*>(this_object)->primitive_string()->string().length());
+}
+
 }

Libraries/LibJS/Runtime/StringPrototype.h

@@ -40,6 +40,8 @@ private:
 
     static Value char_at(Interpreter&);
     static Value repeat(Interpreter&);
+
+    static Value length_getter(Interpreter&);
 };
 
 }