ladybird/Userland/Libraries/LibJS/Runtime/Object.h

/*
 * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
 * Copyright (c) 2020-2021, Linus Groh <linusg@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/HashMap.h>
#include <AK/String.h>
#include <LibJS/Forward.h>
#include <LibJS/Heap/Cell.h>
#include <LibJS/Runtime/IndexedProperties.h>
#include <LibJS/Runtime/MarkedValueList.h>
#include <LibJS/Runtime/PrimitiveString.h>
#include <LibJS/Runtime/PropertyDescriptor.h>
#include <LibJS/Runtime/PropertyName.h>
#include <LibJS/Runtime/Shape.h>
#include <LibJS/Runtime/Value.h>

namespace JS {

#define JS_OBJECT(class_, base_class) \
public:                               \
    using Base = base_class;          \
    virtual const char* class_name() const override { return #class_; }

class Object : public Cell {
public:
    static Object* create(GlobalObject&, Object* prototype);

    explicit Object(Object& prototype);
    explicit Object(Shape&);
    virtual void initialize(GlobalObject&) override;
    virtual ~Object();

    enum class PropertyKind {
        Key,
        Value,
        KeyAndValue,
    };

    enum class PutOwnPropertyMode {
        Put,
        DefineProperty,
    };

    enum class IntegrityLevel {
        Sealed,
        Frozen,
    };

    // Please DO NOT make up your own non-standard methods unless you
    // have a very good reason to do so. If any object abstract
    // operation from the spec is missing, add it instead.
    // Functionality for implementation details like shapes and
    // property storage are obviously exempt from this rule :^)
    //
    // Methods named [[Foo]]() in the spec are named internal_foo()
    // here, as they are "The [[Foo]] internal method of a ... object".
    // They must be virtual and may be overridden. All other methods
    // follow the the regular PascalCase name converted to camel_case
    // naming convention and must not be virtual.

    // 7.1 Type Conversion, https://tc39.es/ecma262/#sec-type-conversion

    Value ordinary_to_primitive(Value::PreferredType preferred_type) const;

    // 7.2 Testing and Comparison Operations, https://tc39.es/ecma262/#sec-testing-and-comparison-operations

    bool is_extensible() const;

    // 7.3 Operations on Objects, https://tc39.es/ecma262/#sec-operations-on-objects

    Value get(PropertyName const&) const;
    bool set(PropertyName const&, Value, bool throw_exceptions);
    bool create_data_property(PropertyName const&, Value);
    bool create_method_property(PropertyName const&, Value);
    bool create_data_property_or_throw(PropertyName const&, Value);
    bool define_property_or_throw(PropertyName const&, PropertyDescriptor const&);
    bool delete_property_or_throw(PropertyName const&);
    bool has_property(PropertyName const&) const;
    bool has_own_property(PropertyName const&) const;
    bool set_integrity_level(IntegrityLevel);
    bool test_integrity_level(IntegrityLevel) const;
    MarkedValueList enumerable_own_property_names(PropertyKind kind) const;

    // 10.1 Ordinary Object Internal Methods and Internal Slots, https://tc39.es/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots

    virtual Object* internal_get_prototype_of() const;
    virtual bool internal_set_prototype_of(Object* prototype);
    virtual bool internal_is_extensible() const;
    virtual bool internal_prevent_extensions();
    virtual Optional<PropertyDescriptor> internal_get_own_property(PropertyName const&) const;
    virtual bool internal_define_own_property(PropertyName const&, PropertyDescriptor const&);
    virtual bool internal_has_property(PropertyName const&) const;
    virtual Value internal_get(PropertyName const&, Value receiver) const;
    virtual bool internal_set(PropertyName const&, Value value, Value receiver);
    virtual bool internal_delete(PropertyName const&);
    virtual MarkedValueList internal_own_property_keys() const;

    // 20.1 Object Objects, https://tc39.es/ecma262/#sec-object-objects

    Object* define_properties(Value properties);

    // Implementation-specific storage abstractions

    enum class CallNativeProperty {
        Yes,
        No,
    };

    Optional<ValueAndAttributes> storage_get(PropertyName const&, CallNativeProperty = CallNativeProperty::Yes) const;
    bool storage_has(PropertyName const&) const;
    void storage_set(PropertyName const&, ValueAndAttributes const&);
    void storage_delete(PropertyName const&);

    // Non-standard methods

    // - Helpers using old, non-standard names but wrapping the standard methods.
    //   FIXME: Update all the code relying on these and remove them.
    bool put(PropertyName const& property_name, Value value, Value receiver = {}) { return internal_set(property_name, value, receiver.value_or(this)); }
    Optional<PropertyDescriptor> get_own_property_descriptor(PropertyName const& property_name) const { return internal_get_own_property(property_name); }
    bool define_property(PropertyName const& property_name, Value value, PropertyAttributes attributes = default_attributes, bool = true)
    {
        return internal_define_own_property(property_name, { .value = value, .writable = attributes.is_writable(), .enumerable = attributes.is_enumerable(), .configurable = attributes.is_configurable() });
    };

    Value get_without_side_effects(const PropertyName&) const;

    bool define_property_without_transition(const PropertyName&, Value value, PropertyAttributes attributes = default_attributes, bool throw_exceptions = true);
    bool define_accessor(const PropertyName&, FunctionObject* getter, FunctionObject* setter, PropertyAttributes attributes = default_attributes, bool throw_exceptions = true);

    bool define_native_function(PropertyName const&, Function<Value(VM&, GlobalObject&)>, i32 length = 0, PropertyAttributes attributes = default_attributes);
    bool define_native_property(PropertyName const&, Function<Value(VM&, GlobalObject&)> getter, Function<void(VM&, GlobalObject&, Value)> setter, PropertyAttributes attributes = default_attributes);
    bool define_native_accessor(PropertyName const&, Function<Value(VM&, GlobalObject&)> getter, Function<Value(VM&, GlobalObject&)> setter, PropertyAttributes attributes = default_attributes);

    virtual bool is_array() const { return false; }
    virtual bool is_function() const { return false; }
    virtual bool is_typed_array() const { return false; }
    virtual bool is_string_object() const { return false; }
    virtual bool is_global_object() const { return false; }
    virtual bool is_proxy_object() const { return false; }
    virtual bool is_native_function() const { return false; }
    virtual bool is_ordinary_function_object() const { return false; }

    // B.3.7 The [[IsHTMLDDA]] Internal Slot, https://tc39.es/ecma262/#sec-IsHTMLDDA-internal-slot
    virtual bool is_htmldda() const { return false; }

    virtual const char* class_name() const override { return "Object"; }
    virtual void visit_edges(Cell::Visitor&) override;
    virtual Value value_of() const { return Value(const_cast<Object*>(this)); }

    Value get_direct(size_t index) const { return m_storage[index]; }

    const IndexedProperties& indexed_properties() const { return m_indexed_properties; }
    IndexedProperties& indexed_properties() { return m_indexed_properties; }
    void set_indexed_property_elements(Vector<Value>&& values) { m_indexed_properties = IndexedProperties(move(values)); }

    [[nodiscard]] Value invoke_internal(const StringOrSymbol& property_name, Optional<MarkedValueList> arguments);

    template<typename... Args>
    [[nodiscard]] ALWAYS_INLINE Value invoke(const StringOrSymbol& property_name, Args... args)
    {
        if constexpr (sizeof...(Args) > 0) {
            MarkedValueList arglist { heap() };
            (..., arglist.append(move(args)));
            return invoke(property_name, move(arglist));
        }

        return invoke(property_name);
    }

    Shape& shape() { return *m_shape; }
    Shape const& shape() const { return *m_shape; }

    GlobalObject& global_object() const { return *shape().global_object(); }

    void ensure_shape_is_unique();

    void enable_transitions() { m_transitions_enabled = true; }
    void disable_transitions() { m_transitions_enabled = false; }

    template<typename T>
    bool fast_is() const = delete;

protected:
    enum class GlobalObjectTag { Tag };
    enum class ConstructWithoutPrototypeTag { Tag };
    explicit Object(GlobalObjectTag);
    Object(ConstructWithoutPrototypeTag, GlobalObject&);

    bool m_is_extensible { true };

private:
    Value call_native_property_getter(NativeProperty& property, Value this_value) const;
    void call_native_property_setter(NativeProperty& property, Value this_value, Value) const;

    void set_shape(Shape&);

    Object* prototype() { return shape().prototype(); }
    Object const* prototype() const { return shape().prototype(); }

    bool m_transitions_enabled { true };
    Shape* m_shape { nullptr };
    Vector<Value> m_storage;
    IndexedProperties m_indexed_properties;
};

template<>
[[nodiscard]] ALWAYS_INLINE Value Object::invoke(const StringOrSymbol& property_name, MarkedValueList arguments) { return invoke_internal(property_name, move(arguments)); }

template<>
[[nodiscard]] ALWAYS_INLINE Value Object::invoke(const StringOrSymbol& property_name, Optional<MarkedValueList> arguments) { return invoke_internal(property_name, move(arguments)); }

template<>
[[nodiscard]] ALWAYS_INLINE Value Object::invoke(const StringOrSymbol& property_name) { return invoke(property_name, Optional<MarkedValueList> {}); }

}