LibJS: Add JS_CELL macro and use it in all JS::Cell subclasses

This is similar to what we already had with JS_OBJECT (and also
JS_ENVIRONMENT) but sits at the top of the Cell inheritance hierarchy.

Userland/Libraries/LibJS/Heap/Cell.h

@@ -14,6 +14,14 @@
 
 namespace JS {
 
+#define JS_CELL(class_, base_class)                \
+public:                                            \
+    using Base = base_class;                       \
+    virtual StringView class_name() const override \
+    {                                              \
+        return #class_##sv;                        \
+    }
+
 class Cell {
     AK_MAKE_NONCOPYABLE(Cell);
     AK_MAKE_NONMOVABLE(Cell);

Userland/Libraries/LibJS/Heap/HeapBlock.h

@@ -97,9 +97,9 @@ private:
     bool has_lazy_freelist() const { return m_next_lazy_freelist_index < cell_count(); }
 
     struct FreelistEntry final : public Cell {
-        FreelistEntry* next { nullptr };
+        JS_CELL(FreelistEntry, Cell);
 
-        virtual StringView class_name() const override { return "FreelistEntry"sv; }
+        FreelistEntry* next { nullptr };
     };
 
     Cell* cell(size_t index)

Userland/Libraries/LibJS/Runtime/Accessor.h

@@ -14,6 +14,8 @@
 namespace JS {
 
 class Accessor final : public Cell {
+    JS_CELL(Accessor, Cell);
+
 public:
     static Accessor* create(VM& vm, FunctionObject* getter, FunctionObject* setter)
     {
@@ -39,8 +41,6 @@ public:
     }
 
 private:
-    StringView class_name() const override { return "Accessor"sv; };
-
     FunctionObject* m_getter { nullptr };
     FunctionObject* m_setter { nullptr };
 };

Userland/Libraries/LibJS/Runtime/Array.h

@@ -35,7 +35,6 @@ public:
         return Array::create_from(realm, values);
     }
 
-    explicit Array(Object& prototype);
     virtual ~Array() override = default;
 
     virtual ThrowCompletionOr<Optional<PropertyDescriptor>> internal_get_own_property(PropertyKey const&) const override;

Userland/Libraries/LibJS/Runtime/BigInt.h

@@ -13,6 +13,8 @@
 namespace JS {
 
 class BigInt final : public Cell {
+    JS_CELL(BigInt, Cell);
+
 public:
     explicit BigInt(Crypto::SignedBigInteger);
     virtual ~BigInt() override = default;
@@ -21,8 +23,6 @@ public:
     const String to_string() const { return String::formatted("{}n", m_big_integer.to_base(10)); }
 
 private:
-    virtual StringView class_name() const override { return "BigInt"sv; }
-
     Crypto::SignedBigInteger m_big_integer;
 };
 

Userland/Libraries/LibJS/Runtime/Environment.h

@@ -23,6 +23,8 @@ public:                                    \
     virtual StringView class_name() const override { return #class_##sv; }
 
 class Environment : public Cell {
+    JS_CELL(Environment, Cell);
+
 public:
     virtual bool has_this_binding() const { return false; }
     virtual ThrowCompletionOr<Value> get_this_binding(VM&) const { return Value {}; }
@@ -48,8 +50,6 @@ public:
     template<typename T>
     bool fast_is() const = delete;
 
-    virtual StringView class_name() const override { return "Environment"sv; }
-
     // This flag is set on the entire variable environment chain when direct eval() is performed.
     // It is used to disable non-local variable access caching.
     bool is_permanently_screwed_by_eval() const { return m_permanently_screwed_by_eval; }

Userland/Libraries/LibJS/Runtime/Intrinsics.h

@@ -13,6 +13,8 @@
 namespace JS {
 
 class Intrinsics final : public Cell {
+    JS_CELL(Intrinsics, Cell);
+
 public:
     static Intrinsics* create(Realm&);
 
@@ -112,7 +114,6 @@ public:
 #undef __JS_ENUMERATE
 
 private:
-    virtual StringView class_name() const override { return "Intrinsics"sv; }
     virtual void visit_edges(Visitor&) override;
 
     void initialize_intrinsics(Realm&);

Userland/Libraries/LibJS/Runtime/Object.h

@@ -46,6 +46,8 @@ struct PrivateElement {
 };
 
 class Object : public Cell {
+    JS_CELL(Object, Cell);
+
 public:
     static Object* create(Realm&, Object* prototype);
 
@@ -174,7 +176,6 @@ public:
     bool has_parameter_map() const { return m_has_parameter_map; }
     void set_has_parameter_map() { m_has_parameter_map = true; }
 
-    virtual StringView class_name() const override { return "Object"sv; }
     virtual void visit_edges(Cell::Visitor&) override;
 
     Value get_direct(size_t index) const { return m_storage[index]; }

Userland/Libraries/LibJS/Runtime/PrimitiveString.h

@@ -16,6 +16,8 @@
 namespace JS {
 
 class PrimitiveString final : public Cell {
+    JS_CELL(PrimitiveString, Cell);
+
 public:
     explicit PrimitiveString(PrimitiveString&, PrimitiveString&);
     explicit PrimitiveString(String);
@@ -37,7 +39,6 @@ public:
     Optional<Value> get(VM&, PropertyKey const&) const;
 
 private:
-    virtual StringView class_name() const override { return "PrimitiveString"sv; }
     virtual void visit_edges(Cell::Visitor&) override;
 
     void resolve_rope_if_needed() const;

Userland/Libraries/LibJS/Runtime/PrivateEnvironment.h

@@ -28,6 +28,8 @@ struct PrivateName {
 };
 
 class PrivateEnvironment : public Cell {
+    JS_CELL(PrivateEnvironment, Cell);
+
 public:
     explicit PrivateEnvironment(PrivateEnvironment* parent);
 
@@ -36,7 +38,6 @@ public:
     void add_private_name(Badge<ClassExpression>, FlyString description);
 
 private:
-    virtual StringView class_name() const override { return "PrivateEnvironment"sv; }
     virtual void visit_edges(Visitor&) override;
 
     auto find_private_name(FlyString const& description) const

Userland/Libraries/LibJS/Runtime/PromiseReaction.h

@@ -65,6 +65,8 @@ ThrowCompletionOr<PromiseCapability> new_promise_capability(VM& vm, Value constr
 
 // 27.2.1.2 PromiseReaction Records, https://tc39.es/ecma262/#sec-promisereaction-records
 class PromiseReaction final : public Cell {
+    JS_CELL(PromiseReaction, Cell);
+
 public:
     enum class Type {
         Fulfill,
@@ -86,7 +88,6 @@ public:
     Optional<JobCallback> const& handler() const { return m_handler; }
 
 private:
-    virtual StringView class_name() const override { return "PromiseReaction"sv; }
     virtual void visit_edges(Visitor&) override;
 
     Type m_type;

Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.h

@@ -13,6 +13,8 @@
 namespace JS {
 
 struct RemainingElements final : public Cell {
+    JS_CELL(RemainingElements, Cell);
+
     RemainingElements() = default;
 
     explicit RemainingElements(u64 initial_value)
@@ -20,12 +22,12 @@ struct RemainingElements final : public Cell {
     {
     }
 
-    virtual StringView class_name() const override { return "RemainingElements"sv; }
-
     u64 value { 0 };
 };
 
 class PromiseValueList final : public Cell {
+    JS_CELL(PromiseValueList, Cell);
+
 public:
     PromiseValueList()
     {
@@ -35,7 +37,6 @@ public:
     Vector<Value> const& values() const { return m_values; }
 
 private:
-    virtual StringView class_name() const override { return "PromiseValueList"sv; }
     virtual void visit_edges(Visitor&) override;
 
     Vector<Value> m_values;

Userland/Libraries/LibJS/Runtime/PromiseResolvingFunction.h

@@ -12,9 +12,9 @@
 namespace JS {
 
 struct AlreadyResolved final : public Cell {
-    bool value { false };
+    JS_CELL(AlreadyResolved, Cell);
 
-    virtual StringView class_name() const override { return "AlreadyResolved"sv; }
+    bool value { false };
 
 protected:
     // Allocated cells must be >= sizeof(FreelistEntry), which is 24 bytes -

Userland/Libraries/LibJS/Runtime/Realm.h

@@ -20,6 +20,8 @@ namespace JS {
 class Realm final
     : public Cell
     , public Weakable<Realm> {
+    JS_CELL(Realm, Cell);
+
 public:
     struct HostDefined {
         virtual ~HostDefined() = default;
@@ -47,7 +49,6 @@ public:
     void set_host_defined(OwnPtr<HostDefined> host_defined) { m_host_defined = move(host_defined); }
 
 private:
-    virtual StringView class_name() const override { return "Realm"sv; }
     virtual void visit_edges(Visitor&) override;
 
     Intrinsics* m_intrinsics { nullptr };                // [[Intrinsics]]

Userland/Libraries/LibJS/Runtime/Shape.h

@@ -37,6 +37,8 @@ struct TransitionKey {
 class Shape final
     : public Cell
     , public Weakable<Shape> {
+    JS_CELL(Shape, Cell);
+
 public:
     virtual ~Shape() override = default;
 
@@ -84,7 +86,6 @@ public:
     void reconfigure_property_in_unique_shape(StringOrSymbol const& property_key, PropertyAttributes attributes);
 
 private:
-    virtual StringView class_name() const override { return "Shape"sv; }
     virtual void visit_edges(Visitor&) override;
 
     Shape* get_or_prune_cached_forward_transition(TransitionKey const&);

Userland/Libraries/LibJS/Runtime/Symbol.h

@@ -13,6 +13,7 @@
 namespace JS {
 
 class Symbol final : public Cell {
+    JS_CELL(Symbol, Cell);
     AK_MAKE_NONCOPYABLE(Symbol);
     AK_MAKE_NONMOVABLE(Symbol);
 
@@ -26,8 +27,6 @@ public:
     String to_string() const { return String::formatted("Symbol({})", description()); }
 
 private:
-    virtual StringView class_name() const override { return "Symbol"sv; }
-
     Optional<String> m_description;
     bool m_is_global;
 };