LibJS: Convert internal_get_prototype_of() to ThrowCompletionOr

Author: https://github.com/linusg
Commit: https://github.com/SerenityOS/serenity/commit/5148150e1cc
Pull-request: https://github.com/SerenityOS/serenity/pull/10266
Reviewed-by: https://github.com/IdanHo ✅

Meta/Lagom/Tools/CodeGenerators/LibWeb/WrapperGenerator.cpp

@@ -1654,9 +1654,7 @@ bool @class_name@::is_named_property_exposed_on_object(JS::PropertyName const& p
                 scoped_generator.append(R"~~~(
     // NOTE: Step 3 is not here as the interface doesn't have the LegacyOverrideBuiltIns extended attribute.
     // 4. Let prototype be O.[[GetPrototypeOf]]().
-    auto* prototype = internal_get_prototype_of();
-    if (vm.exception())
-        return {};
+    auto* prototype = TRY_OR_DISCARD(internal_get_prototype_of());
 
     // 5. While prototype is not null:
     while (prototype) {
@@ -1670,9 +1668,7 @@ bool @class_name@::is_named_property_exposed_on_object(JS::PropertyName const& p
             return false;
 
         // 2. Set prototype to prototype.[[GetPrototypeOf]]().
-        prototype = prototype->internal_get_prototype_of();
-        if (vm.exception())
-            return {};
+        prototype = TRY_OR_DISCARD(prototype->internal_get_prototype_of());
     }
 
     // 6. Return true.

Userland/Libraries/LibJS/AST.cpp

@@ -580,9 +580,7 @@ Value ForInStatement::execute(Interpreter& interpreter, GlobalObject& global_obj
                 }
             }
         }
-        object = object->internal_get_prototype_of();
-        if (interpreter.exception())
-            return {};
+        object = TRY_OR_DISCARD(object->internal_get_prototype_of());
     }
     return last_value;
 }

Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp

@@ -383,9 +383,18 @@ Environment& get_this_environment(VM& vm)
 // 13.3.7.2 GetSuperConstructor ( ), https://tc39.es/ecma262/#sec-getsuperconstructor
 Object* get_super_constructor(VM& vm)
 {
+    // 1. Let envRec be GetThisEnvironment().
     auto& env = get_this_environment(vm);
+
+    // 2. Assert: envRec is a function Environment Record.
+    // 3. Let activeFunction be envRec.[[FunctionObject]].
+    // 4. Assert: activeFunction is an ECMAScript function object.
     auto& active_function = verify_cast<FunctionEnvironment>(env).function_object();
-    auto* super_constructor = active_function.internal_get_prototype_of();
+
+    // 5. Let superConstructor be ! activeFunction.[[GetPrototypeOf]]().
+    auto* super_constructor = active_function.internal_get_prototype_of().release_value();
+
+    // 6. Return superConstructor.
     return super_constructor;
 }
 

Userland/Libraries/LibJS/Runtime/FunctionEnvironment.cpp

@@ -35,7 +35,7 @@ Value FunctionEnvironment::get_super_base() const
     auto home_object = m_function_object->home_object();
     if (!home_object)
         return js_undefined();
-    return home_object->internal_get_prototype_of();
+    return TRY_OR_DISCARD(home_object->internal_get_prototype_of());
 }
 
 // 9.1.1.3.2 HasThisBinding ( ), https://tc39.es/ecma262/#sec-function-environment-records-hasthisbinding

Userland/Libraries/LibJS/Runtime/Object.cpp

@@ -489,7 +489,7 @@ MarkedValueList Object::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
 
 // 10.1.1 [[GetPrototypeOf]] ( ), https://tc39.es/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots-getprototypeof
-Object* Object::internal_get_prototype_of() const
+ThrowCompletionOr<Object*> Object::internal_get_prototype_of() const
 {
     // 1. Return O.[[Prototype]].
     return const_cast<Object*>(prototype());
@@ -645,9 +645,7 @@ bool Object::internal_has_property(PropertyName const& property_name) const
         return true;
 
     // 4. Let parent be ? O.[[GetPrototypeOf]]().
-    auto parent = internal_get_prototype_of();
-    if (vm.exception())
-        return {};
+    auto* parent = TRY_OR_DISCARD(internal_get_prototype_of());
 
     // 5. If parent is not null, then
     if (parent) {
@@ -676,9 +674,7 @@ Value Object::internal_get(PropertyName const& property_name, Value receiver) co
     // 3. If desc is undefined, then
     if (!descriptor.has_value()) {
         // a. Let parent be ? O.[[GetPrototypeOf]]().
-        auto parent = internal_get_prototype_of();
-        if (vm.exception())
-            return {};
+        auto* parent = TRY_OR_DISCARD(internal_get_prototype_of());
 
         // b. If parent is null, return undefined.
         if (!parent)
@@ -736,9 +732,7 @@ bool Object::ordinary_set_with_own_descriptor(PropertyName const& property_name,
     // 2. If ownDesc is undefined, then
     if (!own_descriptor.has_value()) {
         // a. Let parent be ? O.[[GetPrototypeOf]]().
-        auto parent = internal_get_prototype_of();
-        if (vm.exception())
-            return {};
+        auto* parent = TRY_OR_DISCARD(internal_get_prototype_of());
 
         // b. If parent is not null, then
         if (parent) {
@@ -882,14 +876,10 @@ MarkedValueList Object::internal_own_property_keys() const
 // 10.4.7.2 SetImmutablePrototype ( O, V ), https://tc39.es/ecma262/#sec-set-immutable-prototype
 bool Object::set_immutable_prototype(Object* prototype)
 {
-    auto& vm = this->vm();
-
     // 1. Assert: Either Type(V) is Object or Type(V) is Null.
 
     // 2. Let current be ? O.[[GetPrototypeOf]]().
-    auto* current = internal_get_prototype_of();
-    if (vm.exception())
-        return {};
+    auto* current = TRY_OR_DISCARD(internal_get_prototype_of());
 
     // 3. If SameValue(V, current) is true, return true.
     if (prototype == current)

Userland/Libraries/LibJS/Runtime/Object.h

@@ -12,6 +12,7 @@
 #include <AK/String.h>
 #include <LibJS/Forward.h>
 #include <LibJS/Heap/Cell.h>
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/IndexedProperties.h>
 #include <LibJS/Runtime/MarkedValueList.h>
 #include <LibJS/Runtime/PrimitiveString.h>
@@ -90,7 +91,7 @@ public:
 
     // 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 ThrowCompletionOr<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();

Userland/Libraries/LibJS/Runtime/ObjectConstructor.cpp

@@ -140,7 +140,7 @@ JS_DEFINE_NATIVE_FUNCTION(ObjectConstructor::get_prototype_of)
         return {};
 
     // 2. Return ? obj.[[GetPrototypeOf]]().
-    return object->internal_get_prototype_of();
+    return TRY_OR_DISCARD(object->internal_get_prototype_of());
 }
 
 // 20.1.2.21 Object.setPrototypeOf ( O, proto ), https://tc39.es/ecma262/#sec-object.setprototypeof

Userland/Libraries/LibJS/Runtime/ObjectPrototype.cpp

@@ -187,7 +187,7 @@ JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::is_prototype_of)
         return {};
 
     for (;;) {
-        object = object->internal_get_prototype_of();
+        object = TRY_OR_DISCARD(object->internal_get_prototype_of());
         if (!object)
             return Value(false);
         if (same_value(this_object, object))
@@ -267,9 +267,7 @@ JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::lookup_getter)
                 return *desc->get ?: js_undefined();
             return js_undefined();
         }
-        object = object->internal_get_prototype_of();
-        if (vm.exception())
-            return {};
+        object = TRY_OR_DISCARD(object->internal_get_prototype_of());
     }
 
     return js_undefined();
@@ -295,9 +293,7 @@ JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::lookup_setter)
                 return *desc->set ?: js_undefined();
             return js_undefined();
         }
-        object = object->internal_get_prototype_of();
-        if (vm.exception())
-            return {};
+        object = TRY_OR_DISCARD(object->internal_get_prototype_of());
     }
 
     return js_undefined();
@@ -309,10 +305,7 @@ JS_DEFINE_NATIVE_FUNCTION(ObjectPrototype::proto_getter)
     auto object = vm.this_value(global_object).to_object(global_object);
     if (vm.exception())
         return {};
-    auto proto = object->internal_get_prototype_of();
-    if (vm.exception())
-        return {};
-    return proto;
+    return TRY_OR_DISCARD(object->internal_get_prototype_of());
 }
 
 // B.2.2.1.2 set Object.prototype.__proto__, https://tc39.es/ecma262/#sec-set-object.prototype.__proto__

Userland/Libraries/LibJS/Runtime/ProxyObject.cpp

@@ -45,7 +45,7 @@ static Value property_name_to_value(VM& vm, PropertyName const& name)
 }
 
 // 10.5.1 [[GetPrototypeOf]] ( ), https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-getprototypeof
-Object* ProxyObject::internal_get_prototype_of() const
+ThrowCompletionOr<Object*> ProxyObject::internal_get_prototype_of() const
 {
     auto& vm = this->vm();
     auto& global_object = this->global_object();
@@ -53,51 +53,43 @@ Object* ProxyObject::internal_get_prototype_of() const
     // 1. Let handler be O.[[ProxyHandler]].
 
     // 2. If handler is null, throw a TypeError exception.
-    if (m_is_revoked) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyRevoked);
-        return {};
-    }
+    if (m_is_revoked)
+        return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyRevoked);
 
     // 3. Assert: Type(handler) is Object.
     // 4. Let target be O.[[ProxyTarget]].
 
     // 5. Let trap be ? GetMethod(handler, "getPrototypeOf").
-    auto trap = TRY_OR_DISCARD(Value(&m_handler).get_method(global_object, vm.names.getPrototypeOf));
+    auto trap = TRY(Value(&m_handler).get_method(global_object, vm.names.getPrototypeOf));
 
     // 6. If trap is undefined, then
     if (!trap) {
         // a. Return ? target.[[GetPrototypeOf]]().
-        return m_target.internal_get_prototype_of();
+        return TRY(m_target.internal_get_prototype_of());
     }
 
     // 7. Let handlerProto be ? Call(trap, handler, « target »).
-    auto handler_proto = TRY_OR_DISCARD(vm.call(*trap, &m_handler, &m_target));
+    auto handler_proto = TRY(vm.call(*trap, &m_handler, &m_target));
 
     // 8. If Type(handlerProto) is neither Object nor Null, throw a TypeError exception.
-    if (!handler_proto.is_object() && !handler_proto.is_null()) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyGetPrototypeOfReturn);
-        return {};
-    }
+    if (!handler_proto.is_object() && !handler_proto.is_null())
+        return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyGetPrototypeOfReturn);
 
     // 9. Let extensibleTarget be ? IsExtensible(target).
     auto extensible_target = m_target.is_extensible();
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
 
     // 10. If extensibleTarget is true, return handlerProto.
     if (extensible_target)
         return handler_proto.is_null() ? nullptr : &handler_proto.as_object();
 
     // 11. Let targetProto be ? target.[[GetPrototypeOf]]().
-    auto target_proto = m_target.internal_get_prototype_of();
-    if (vm.exception())
-        return {};
+    auto* target_proto = TRY(m_target.internal_get_prototype_of());
 
     // 12. If SameValue(handlerProto, targetProto) is false, throw a TypeError exception.
-    if (!same_value(handler_proto, target_proto)) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyGetPrototypeOfNonExtensible);
-        return {};
-    }
+    if (!same_value(handler_proto, target_proto))
+        return vm.throw_completion<TypeError>(global_object, ErrorType::ProxyGetPrototypeOfNonExtensible);
 
     // 13. Return handlerProto.
     return handler_proto.is_null() ? nullptr : &handler_proto.as_object();
@@ -147,9 +139,7 @@ bool ProxyObject::internal_set_prototype_of(Object* prototype)
         return true;
 
     // 12. Let targetProto be ? target.[[GetPrototypeOf]]().
-    auto* target_proto = m_target.internal_get_prototype_of();
-    if (vm.exception())
-        return {};
+    auto* target_proto = TRY_OR_DISCARD(m_target.internal_get_prototype_of());
 
     // 13. If SameValue(V, targetProto) is false, throw a TypeError exception.
     if (!same_value(prototype, target_proto)) {

Userland/Libraries/LibJS/Runtime/ProxyObject.h

@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/FunctionObject.h>
 
 namespace JS {
@@ -34,7 +35,7 @@ public:
 
     // 10.5 Proxy Object Internal Methods and Internal Slots, https://tc39.es/ecma262/#sec-proxy-object-internal-methods-and-internal-slots
 
-    virtual Object* internal_get_prototype_of() const override;
+    virtual ThrowCompletionOr<Object*> internal_get_prototype_of() const override;
     virtual bool internal_set_prototype_of(Object* prototype) override;
     virtual bool internal_is_extensible() const override;
     virtual bool internal_prevent_extensions() override;

Userland/Libraries/LibJS/Runtime/ReflectObject.cpp

@@ -212,7 +212,7 @@ JS_DEFINE_NATIVE_FUNCTION(ReflectObject::get_prototype_of)
     }
 
     // 2. Return ? target.[[GetPrototypeOf]]().
-    return target.as_object().internal_get_prototype_of();
+    return TRY_OR_DISCARD(target.as_object().internal_get_prototype_of());
 }
 
 // 28.1.8 Reflect.has ( target, propertyKey ), https://tc39.es/ecma262/#sec-reflect.has

Userland/Libraries/LibJS/Runtime/Value.cpp

@@ -1334,9 +1334,7 @@ Value ordinary_has_instance(GlobalObject& global_object, Value lhs, Value rhs)
         return {};
     }
     while (true) {
-        lhs_object = lhs_object->internal_get_prototype_of();
-        if (vm.exception())
-            return {};
+        lhs_object = TRY_OR_DISCARD(lhs_object->internal_get_prototype_of());
         if (!lhs_object)
             return Value(false);
         if (same_value(rhs_prototype, lhs_object))

Userland/Services/WebContent/ConsoleGlobalObject.cpp

@@ -5,6 +5,7 @@
  */
 
 #include "ConsoleGlobalObject.h"
+#include <LibJS/Runtime/Completion.h>
 #include <LibWeb/Bindings/NodeWrapper.h>
 #include <LibWeb/Bindings/NodeWrapperFactory.h>
 #include <LibWeb/Bindings/WindowObject.h>
@@ -36,7 +37,7 @@ void ConsoleGlobalObject::visit_edges(Visitor& visitor)
     visitor.visit(m_window_object);
 }
 
-JS::Object* ConsoleGlobalObject::internal_get_prototype_of() const
+JS::ThrowCompletionOr<JS::Object*> ConsoleGlobalObject::internal_get_prototype_of() const
 {
     return m_window_object->internal_get_prototype_of();
 }

Userland/Services/WebContent/ConsoleGlobalObject.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <LibJS/Forward.h>
+#include <LibJS/Runtime/Completion.h>
 #include <LibJS/Runtime/GlobalObject.h>
 
 namespace Web::Bindings {
@@ -22,7 +23,7 @@ public:
     ConsoleGlobalObject(Web::Bindings::WindowObject&);
     virtual ~ConsoleGlobalObject() override;
 
-    virtual Object* internal_get_prototype_of() const override;
+    virtual JS::ThrowCompletionOr<Object*> internal_get_prototype_of() const override;
     virtual bool internal_set_prototype_of(Object* prototype) override;
     virtual bool internal_is_extensible() const override;
     virtual bool internal_prevent_extensions() override;