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LibJS: Let WrappedFunction inherit target name and length

This is a normative change in the ShadowRealm spec.

See: b73a1dc
This commit is contained in:
Linus Groh 2022-01-24 19:14:04 +00:00
parent 886d6c62f9
commit e20efaa083
6 changed files with 119 additions and 21 deletions

View file

@ -277,6 +277,7 @@
M(UnknownIdentifier, "'{}' is not defined") \
M(UnsupportedDeleteSuperProperty, "Can't delete a property on 'super'") \
M(WrappedFunctionCallThrowCompletion, "Call of wrapped target function did not complete normally") \
M(WrappedFunctionCopyNameAndLengthThrowCompletion, "Trying to copy target name and length did not complete normally") \
M(URIMalformed, "URI malformed") /* LibWeb bindings */ \
M(NotAByteString, "Argument to {}() must be a byte string") \
M(BadArgCountOne, "{}() needs one argument") \

View file

@ -31,7 +31,67 @@ void ShadowRealm::visit_edges(Visitor& visitor)
visitor.visit(&m_shadow_realm);
}
// 3.1.1 PerformShadowRealmEval ( sourceText, callerRealm, evalRealm ), https://tc39.es/proposal-shadowrealm/#sec-performshadowrealmeval
// 3.1.2 CopyNameAndLength ( F: a function object, Target: a function object, prefix: a String, optional argCount: a Number, ), https://tc39.es/proposal-shadowrealm/#sec-copynameandlength
ThrowCompletionOr<void> copy_name_and_length(GlobalObject& global_object, FunctionObject& function, FunctionObject& target, StringView prefix, Optional<unsigned> arg_count)
{
auto& vm = global_object.vm();
// 1. If argCount is undefined, then set argCount to 0.
if (!arg_count.has_value())
arg_count = 0;
// 2. Let L be 0.
double length = 0;
// 3. Let targetHasLength be ? HasOwnProperty(Target, "length").
auto target_has_length = TRY(target.has_own_property(vm.names.length));
// 4. If targetHasLength is true, then
if (target_has_length) {
// a. Let targetLen be ? Get(Target, "length").
auto target_length = TRY(target.get(vm.names.length));
// b. If Type(targetLen) is Number, then
if (target_length.is_number()) {
// i. If targetLen is +∞𝔽, set L to +∞.
if (target_length.is_positive_infinity()) {
length = target_length.as_double();
}
// ii. Else if targetLen is -∞𝔽, set L to 0.
else if (target_length.is_negative_infinity()) {
length = 0;
}
// iii. Else,
else {
// 1. Let targetLenAsInt be ! ToIntegerOrInfinity(targetLen).
auto target_length_as_int = MUST(target_length.to_integer_or_infinity(global_object));
// 2. Assert: targetLenAsInt is finite.
VERIFY(!isinf(target_length_as_int));
// 3. Set L to max(targetLenAsInt - argCount, 0).
length = max(target_length_as_int - *arg_count, 0);
}
}
}
// 5. Perform ! SetFunctionLength(F, L).
function.set_function_length(length);
// 6. Let targetName be ? Get(Target, "name").
auto target_name = TRY(target.get(vm.names.name));
// 7. If Type(targetName) is not String, set targetName to the empty String.
if (!target_name.is_string())
target_name = js_string(vm, String::empty());
// 8. Perform ! SetFunctionName(F, targetName, prefix).
function.set_function_name({ target_name.as_string().string() }, prefix);
return {};
}
// 3.1.3 PerformShadowRealmEval ( sourceText, callerRealm, evalRealm ), https://tc39.es/proposal-shadowrealm/#sec-performshadowrealmeval
ThrowCompletionOr<Value> perform_shadow_realm_eval(GlobalObject& global_object, StringView source_text, Realm& caller_realm, Realm& eval_realm)
{
auto& vm = global_object.vm();
@ -143,7 +203,7 @@ ThrowCompletionOr<Value> perform_shadow_realm_eval(GlobalObject& global_object,
// NOTE: Also see "Editor's Note" in the spec regarding the TypeError above.
}
// 3.1.2 ShadowRealmImportValue ( specifierString, exportNameString, callerRealm, evalRealm, evalContext ), https://tc39.es/proposal-shadowrealm/#sec-shadowrealmimportvalue
// 3.1.4 ShadowRealmImportValue ( specifierString, exportNameString, callerRealm, evalRealm, evalContext ), https://tc39.es/proposal-shadowrealm/#sec-shadowrealmimportvalue
ThrowCompletionOr<Value> shadow_realm_import_value(GlobalObject& global_object, String specifier_string, String export_name_string, Realm& caller_realm, Realm& eval_realm, ExecutionContext& eval_context)
{
auto& vm = global_object.vm();
@ -227,7 +287,7 @@ ThrowCompletionOr<Value> shadow_realm_import_value(GlobalObject& global_object,
return verify_cast<Promise>(inner_capability.promise)->perform_then(on_fulfilled, throw_type_error, promise_capability);
}
// 3.1.3 GetWrappedValue ( callerRealm, value ), https://tc39.es/proposal-shadowrealm/#sec-getwrappedvalue
// 3.1.5 GetWrappedValue ( callerRealm, value ), https://tc39.es/proposal-shadowrealm/#sec-getwrappedvalue
ThrowCompletionOr<Value> get_wrapped_value(GlobalObject& global_object, Realm& caller_realm, Value value)
{
auto& vm = global_object.vm();
@ -240,8 +300,8 @@ ThrowCompletionOr<Value> get_wrapped_value(GlobalObject& global_object, Realm& c
if (!value.is_function())
return vm.throw_completion<TypeError>(global_object, ErrorType::ShadowRealmWrappedValueNonFunctionObject, value);
// b. Return ! WrappedFunctionCreate(callerRealm, value).
return WrappedFunction::create(global_object, caller_realm, value.as_function());
// b. Return ? WrappedFunctionCreate(callerRealm, value).
return TRY(WrappedFunction::create(global_object, caller_realm, value.as_function()));
}
// 3. Return value.

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
* Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
@ -32,6 +32,7 @@ private:
ExecutionContext m_execution_context; // [[ExecutionContext]]
};
ThrowCompletionOr<void> copy_name_and_length(GlobalObject&, FunctionObject& function, FunctionObject& target, StringView prefix, Optional<unsigned> arg_count = {});
ThrowCompletionOr<Value> perform_shadow_realm_eval(GlobalObject&, StringView source_text, Realm& caller_realm, Realm& eval_realm);
ThrowCompletionOr<Value> shadow_realm_import_value(GlobalObject&, String specifier_string, String export_name_string, Realm& caller_realm, Realm& eval_realm, ExecutionContext& eval_context);
ThrowCompletionOr<Value> get_wrapped_value(GlobalObject&, Realm& caller_realm, Value);

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
* Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
@ -10,24 +10,29 @@
namespace JS {
// 2.2 WrappedFunctionCreate ( callerRealm, targetFunction ), https://tc39.es/proposal-shadowrealm/#sec-wrappedfunctioncreate
WrappedFunction* WrappedFunction::create(GlobalObject& global_object, Realm& caller_realm, FunctionObject& target_function)
// 3.1.1 WrappedFunctionCreate ( callerRealm: a Realm Record, Target: a function object, ), https://tc39.es/proposal-shadowrealm/#sec-wrappedfunctioncreate
ThrowCompletionOr<WrappedFunction*> WrappedFunction::create(GlobalObject& global_object, Realm& caller_realm, FunctionObject& target)
{
// 1. Assert: callerRealm is a Realm Record.
// 2. Assert: IsCallable(targetFunction) is true.
auto& vm = global_object.vm();
// 3. Let internalSlotsList be the internal slots listed in Table 2, plus [[Prototype]] and [[Extensible]].
// 4. Let obj be ! MakeBasicObject(internalSlotsList).
// 1. Let internalSlotsList be the internal slots listed in Table 2, plus [[Prototype]] and [[Extensible]].
// 2. Let wrapped be ! MakeBasicObject(internalSlotsList).
// 3. Set wrapped.[[Prototype]] to callerRealm.[[Intrinsics]].[[%Function.prototype%]].
// 4. Set wrapped.[[Call]] as described in 2.1.
// 5. Set wrapped.[[WrappedTargetFunction]] to Target.
// 6. Set wrapped.[[Realm]] to callerRealm.
auto& prototype = *caller_realm.global_object().function_prototype();
auto* object = global_object.heap().allocate<WrappedFunction>(global_object, caller_realm, target_function, prototype);
auto* wrapped = global_object.heap().allocate<WrappedFunction>(global_object, caller_realm, target, prototype);
// 5. Set obj.[[Prototype]] to callerRealm.[[Intrinsics]].[[%Function.prototype%]].
// 6. Set obj.[[Call]] as described in 2.1.
// 7. Set obj.[[WrappedTargetFunction]] to targetFunction.
// 8. Set obj.[[Realm]] to callerRealm.
// 7. Let result be CopyNameAndLength(wrapped, Target, "wrapped").
auto result = copy_name_and_length(global_object, *wrapped, target, "wrapped"sv);
// 9. Return obj.
return object;
// 8. If result is an Abrupt Completion, throw a TypeError exception.
if (result.is_throw_completion())
return vm.throw_completion<TypeError>(global_object, ErrorType::WrappedFunctionCopyNameAndLengthThrowCompletion);
// 9. Return wrapped.
return wrapped;
}
// 2 Wrapped Function Exotic Objects, https://tc39.es/proposal-shadowrealm/#sec-wrapped-function-exotic-objects

View file

@ -15,7 +15,7 @@ class WrappedFunction final : public FunctionObject {
JS_OBJECT(WrappedFunction, FunctionObject);
public:
static WrappedFunction* create(GlobalObject&, Realm& caller_realm, FunctionObject& target_function);
static ThrowCompletionOr<WrappedFunction*> create(GlobalObject&, Realm& caller_realm, FunctionObject& target_function);
WrappedFunction(Realm&, FunctionObject&, Object& prototype);
virtual ~WrappedFunction() = default;

View file

@ -46,6 +46,37 @@ describe("normal behavior", () => {
expect(typeof wrappedFunction).toBe("function");
expect(Object.getPrototypeOf(wrappedFunction)).toBe(Function.prototype);
expect(shadowRealm.evaluate("(function () {})").name).toBe("wrapped ");
expect(shadowRealm.evaluate("(function foo() {})").name).toBe("wrapped foo");
expect(shadowRealm.evaluate("(function () {})")).toHaveLength(0);
expect(shadowRealm.evaluate("(function (foo, bar) {})")).toHaveLength(2);
expect(
shadowRealm.evaluate(
"Object.defineProperty(function () {}, 'length', { get() { return -Infinity } })"
)
).toHaveLength(0);
expect(
shadowRealm.evaluate(
"Object.defineProperty(function () {}, 'length', { get() { return Infinity } })"
)
).toHaveLength(Infinity);
for (const property of ["name", "length"]) {
expect(() => {
shadowRealm.evaluate(
`
function foo() {}
Object.defineProperty(foo, "${property}", {
get() { throw Error(); }
});
`
);
}).toThrowWithMessage(
TypeError,
"Trying to copy target name and length did not complete normally"
);
}
expect(() => {
shadowRealm.evaluate("(function () { throw Error(); })")();
}).toThrowWithMessage(