LibJS: Remove unnecessary FunctionObject::name() virtual

This allows us to remove the BoundFunction::m_name field, which we
were initializing with a formatted FlyString on every function binding,
despite never using it for anything.

Libraries/LibJS/AST.cpp

@@ -69,7 +69,7 @@ static void update_function_name(Value value, FlyString const& name)
     if (!value.is_function())
         return;
     auto& function = value.as_function();
-    if (is<ECMAScriptFunctionObject>(function) && function.name().is_empty())
+    if (is<ECMAScriptFunctionObject>(function) && static_cast<ECMAScriptFunctionObject const&>(function).name().is_empty())
         static_cast<ECMAScriptFunctionObject&>(function).set_name(name);
 }
 

Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -1212,14 +1212,14 @@ inline ThrowCompletionOr<void> put_by_property_key(VM& vm, Value base, Value thi
     switch (kind) {
     case Op::PropertyKind::Getter: {
         auto& function = value.as_function();
-        if (function.name().is_empty() && is<ECMAScriptFunctionObject>(function))
+        if (is<ECMAScriptFunctionObject>(function) && static_cast<ECMAScriptFunctionObject const&>(function).name().is_empty())
             static_cast<ECMAScriptFunctionObject*>(&function)->set_name(MUST(String::formatted("get {}", name)));
         object->define_direct_accessor(name, &function, nullptr, Attribute::Configurable | Attribute::Enumerable);
         break;
     }
     case Op::PropertyKind::Setter: {
         auto& function = value.as_function();
-        if (function.name().is_empty() && is<ECMAScriptFunctionObject>(function))
+        if (is<ECMAScriptFunctionObject>(function) && static_cast<ECMAScriptFunctionObject const&>(function).name().is_empty())
             static_cast<ECMAScriptFunctionObject*>(&function)->set_name(MUST(String::formatted("set {}", name)));
         object->define_direct_accessor(name, nullptr, &function, Attribute::Configurable | Attribute::Enumerable);
         break;

Libraries/LibJS/Runtime/BoundFunction.cpp

@@ -39,8 +39,6 @@ BoundFunction::BoundFunction(Realm& realm, FunctionObject& bound_target_function
     , m_bound_target_function(&bound_target_function)
     , m_bound_this(bound_this)
     , m_bound_arguments(move(bound_arguments))
-    // FIXME: Non-standard and redundant, remove.
-    , m_name(MUST(String::formatted("bound {}", bound_target_function.name())))
 {
 }
 

Libraries/LibJS/Runtime/BoundFunction.h

@@ -23,7 +23,6 @@ public:
     virtual ThrowCompletionOr<Value> internal_call(Value this_argument, ReadonlySpan<Value> arguments_list) override;
     virtual ThrowCompletionOr<GC::Ref<Object>> internal_construct(ReadonlySpan<Value> arguments_list, FunctionObject& new_target) override;
 
-    virtual FlyString const& name() const override { return m_name; }
     virtual bool is_strict_mode() const override { return m_bound_target_function->is_strict_mode(); }
     virtual bool has_constructor() const override { return m_bound_target_function->has_constructor(); }
 
@@ -39,8 +38,6 @@ private:
     GC::Ptr<FunctionObject> m_bound_target_function; // [[BoundTargetFunction]]
     Value m_bound_this;                              // [[BoundThis]]
     Vector<Value> m_bound_arguments;                 // [[BoundArguments]]
-
-    FlyString m_name;
 };
 
 }

Libraries/LibJS/Runtime/ECMAScriptFunctionObject.h

@@ -127,7 +127,7 @@ public:
     Statement const& ecmascript_code() const { return *shared_data().m_ecmascript_code; }
     [[nodiscard]] virtual FunctionParameters const& formal_parameters() const override { return *shared_data().m_formal_parameters; }
 
-    virtual FlyString const& name() const override { return shared_data().m_name; }
+    FlyString const& name() const { return shared_data().m_name; }
     void set_name(FlyString const& name);
 
     void set_is_class_constructor() { const_cast<SharedFunctionInstanceData&>(shared_data()).m_is_class_constructor = true; }

Libraries/LibJS/Runtime/FunctionObject.h

@@ -26,8 +26,6 @@ public:
     virtual ThrowCompletionOr<Value> internal_call(Value this_argument, ReadonlySpan<Value> arguments_list) = 0;
     virtual ThrowCompletionOr<GC::Ref<Object>> internal_construct([[maybe_unused]] ReadonlySpan<Value> arguments_list, [[maybe_unused]] FunctionObject& new_target) { VERIFY_NOT_REACHED(); }
 
-    virtual FlyString const& name() const = 0;
-
     void set_function_name(Variant<PropertyKey, PrivateName> const& name_arg, Optional<StringView> const& prefix = {});
     void set_function_length(double length);
 

Libraries/LibJS/Runtime/FunctionPrototype.h

@@ -19,7 +19,6 @@ public:
     virtual ~FunctionPrototype() override = default;
 
     virtual ThrowCompletionOr<Value> internal_call(Value this_argument, ReadonlySpan<Value> arguments_list) override;
-    virtual FlyString const& name() const override { return m_name; }
 
 private:
     explicit FunctionPrototype(Realm&);
@@ -29,9 +28,6 @@ private:
     JS_DECLARE_NATIVE_FUNCTION(call);
     JS_DECLARE_NATIVE_FUNCTION(to_string);
     JS_DECLARE_NATIVE_FUNCTION(symbol_has_instance);
-
-    // 20.2.3: The Function prototype object has a "name" property whose value is the empty String.
-    FlyString m_name;
 };
 
 }

Libraries/LibJS/Runtime/NativeFunction.h

@@ -34,7 +34,7 @@ public:
     virtual ThrowCompletionOr<Value> call();
     virtual ThrowCompletionOr<GC::Ref<Object>> construct(FunctionObject& new_target);
 
-    virtual FlyString const& name() const override { return m_name; }
+    FlyString const& name() const { return m_name; }
     virtual bool is_strict_mode() const override;
     virtual bool has_constructor() const override { return false; }
     virtual Realm* realm() const override { return m_realm; }

Libraries/LibJS/Runtime/ProxyObject.cpp

@@ -897,10 +897,4 @@ void ProxyObject::visit_edges(Cell::Visitor& visitor)
     visitor.visit(m_handler);
 }
 
-FlyString const& ProxyObject::name() const
-{
-    VERIFY(is_function());
-    return static_cast<FunctionObject&>(*m_target).name();
-}
-
 }

Libraries/LibJS/Runtime/ProxyObject.h

@@ -21,7 +21,6 @@ public:
 
     virtual ~ProxyObject() override = default;
 
-    virtual FlyString const& name() const override;
     virtual bool has_constructor() const override;
 
     Object const& target() const { return m_target; }

Libraries/LibJS/Runtime/WrappedFunction.h

@@ -22,9 +22,6 @@ public:
 
     virtual ThrowCompletionOr<Value> internal_call(Value this_argument, ReadonlySpan<Value> arguments_list) override;
 
-    // FIXME: Remove this (and stop inventing random internal slots that shouldn't exist, jeez)
-    virtual FlyString const& name() const override { return m_wrapped_target_function->name(); }
-
     virtual Realm* realm() const override { return m_realm; }
 
     FunctionObject const& wrapped_target_function() const { return m_wrapped_target_function; }