summaryrefslogtreecommitdiff
path: root/Userland/Libraries/LibWeb/WebAssembly
diff options
context:
space:
mode:
authorIdan Horowitz <idan.horowitz@gmail.com>2021-10-31 16:53:51 +0200
committerIdan Horowitz <idan.horowitz@gmail.com>2021-10-31 18:20:37 +0200
commit3e8c76d5abc4f1f479b0aa108a3c92eda10a5e63 (patch)
treeb03bcfb8ab5c18b2e437797f2b5d619eea2172ac /Userland/Libraries/LibWeb/WebAssembly
parenta76cd669b1ec953728b9d8352cfb73321f84268a (diff)
downloadserenity-3e8c76d5abc4f1f479b0aa108a3c92eda10a5e63.zip
LibWeb: Convert WebAssemblyObject AOs to ThrowCompletionOr
Diffstat (limited to 'Userland/Libraries/LibWeb/WebAssembly')
-rw-r--r--Userland/Libraries/LibWeb/WebAssembly/WebAssemblyInstanceConstructor.cpp8
-rw-r--r--Userland/Libraries/LibWeb/WebAssembly/WebAssemblyModuleConstructor.cpp8
-rw-r--r--Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.cpp115
-rw-r--r--Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.h6
-rw-r--r--Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTableConstructor.cpp9
-rw-r--r--Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTablePrototype.cpp18
6 files changed, 62 insertions, 102 deletions
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyInstanceConstructor.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyInstanceConstructor.cpp
index d6d034ea82..9511079af4 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyInstanceConstructor.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyInstanceConstructor.cpp
@@ -36,12 +36,8 @@ JS::ThrowCompletionOr<JS::Object*> WebAssemblyInstanceConstructor::construct(Fun
if (!is<WebAssemblyModuleObject>(module_argument))
return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "WebAssembly.Module");
auto& module_object = static_cast<WebAssemblyModuleObject&>(*module_argument);
- auto result = WebAssemblyObject::instantiate_module(module_object.module(), vm, global_object);
- if (result.is_error()) {
- vm.throw_exception(global_object, result.error());
- return JS::throw_completion(result.error());
- }
- return heap().allocate<WebAssemblyInstanceObject>(global_object, global_object, result.value());
+ auto result = TRY(WebAssemblyObject::instantiate_module(module_object.module(), vm, global_object));
+ return heap().allocate<WebAssemblyInstanceObject>(global_object, global_object, result);
}
void WebAssemblyInstanceConstructor::initialize(JS::GlobalObject& global_object)
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyModuleConstructor.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyModuleConstructor.cpp
index da86d1d29d..62703f5e3e 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyModuleConstructor.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyModuleConstructor.cpp
@@ -34,13 +34,9 @@ JS::ThrowCompletionOr<JS::Object*> WebAssemblyModuleConstructor::construct(Funct
auto& global_object = this->global_object();
auto* buffer_object = TRY(vm.argument(0).to_object(global_object));
- auto result = parse_module(global_object, buffer_object);
- if (result.is_error()) {
- vm.throw_exception(global_object, result.error());
- return JS::throw_completion(result.error());
- }
+ auto result = TRY(parse_module(global_object, buffer_object));
- return heap().allocate<WebAssemblyModuleObject>(global_object, global_object, result.release_value());
+ return heap().allocate<WebAssemblyModuleObject>(global_object, global_object, result);
}
void WebAssemblyModuleConstructor::initialize(JS::GlobalObject& global_object)
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.cpp
index 995d1fc6b2..69d73dbf5d 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.cpp
@@ -94,8 +94,10 @@ JS_DEFINE_OLD_NATIVE_FUNCTION(WebAssemblyObject::validate)
return JS::Value { true };
}
-Result<size_t, JS::Value> parse_module(JS::GlobalObject& global_object, JS::Object* buffer_object)
+JS::ThrowCompletionOr<size_t> parse_module(JS::GlobalObject& global_object, JS::Object* buffer_object)
{
+ auto& vm = global_object.vm();
+
ReadonlyBytes data;
if (is<JS::ArrayBuffer>(buffer_object)) {
auto& buffer = static_cast<JS::ArrayBuffer&>(*buffer_object);
@@ -107,8 +109,7 @@ Result<size_t, JS::Value> parse_module(JS::GlobalObject& global_object, JS::Obje
auto& buffer = static_cast<JS::DataView&>(*buffer_object);
data = buffer.viewed_array_buffer()->buffer().span().slice(buffer.byte_offset(), buffer.byte_length());
} else {
- auto error = JS::TypeError::create(global_object, "Not a BufferSource");
- return JS::Value { error };
+ return vm.throw_completion<JS::TypeError>(global_object, "Not a BufferSource");
}
InputMemoryStream stream { data };
auto module_result = Wasm::Module::parse(stream);
@@ -119,8 +120,7 @@ Result<size_t, JS::Value> parse_module(JS::GlobalObject& global_object, JS::Obje
};
if (module_result.is_error()) {
// FIXME: Throw CompileError instead.
- auto error = JS::TypeError::create(global_object, Wasm::parse_error_to_string(module_result.error()));
- return JS::Value { error };
+ return vm.throw_completion<JS::TypeError>(global_object, Wasm::parse_error_to_string(module_result.error()));
}
WebAssemblyObject::s_compiled_modules.append(make<WebAssemblyObject::CompiledWebAssemblyModule>(module_result.release_value()));
@@ -145,26 +145,19 @@ JS_DEFINE_OLD_NATIVE_FUNCTION(WebAssemblyObject::compile)
auto* buffer = buffer_or_error.release_value();
auto result = parse_module(global_object, buffer);
if (result.is_error())
- promise->reject(result.error());
+ promise->reject(result.release_error().value());
else
- promise->fulfill(vm.heap().allocate<WebAssemblyModuleObject>(global_object, global_object, result.value()));
+ promise->fulfill(vm.heap().allocate<WebAssemblyModuleObject>(global_object, global_object, result.release_value()));
return promise;
}
-Result<size_t, JS::Value> WebAssemblyObject::instantiate_module(Wasm::Module const& module, JS::VM& vm, JS::GlobalObject& global_object)
+JS::ThrowCompletionOr<size_t> WebAssemblyObject::instantiate_module(Wasm::Module const& module, JS::VM& vm, JS::GlobalObject& global_object)
{
Wasm::Linker linker { module };
HashMap<Wasm::Linker::Name, Wasm::ExternValue> resolved_imports;
auto import_argument = vm.argument(1);
if (!import_argument.is_undefined()) {
- auto import_object_or_error = import_argument.to_object(global_object);
- if (import_object_or_error.is_error()) {
- vm.clear_exception();
- vm.stop_unwind();
- return import_object_or_error.throw_completion().value();
- }
- [[maybe_unused]] auto* import_object = import_object_or_error.release_value();
-
+ auto* import_object = TRY(import_argument.to_object(global_object));
dbgln("Trying to resolve stuff because import object was specified");
for (const Wasm::Linker::Name& import_name : linker.unresolved_imports()) {
dbgln("Trying to resolve {}::{}", import_name.module, import_name.name);
@@ -180,13 +173,13 @@ Result<size_t, JS::Value> WebAssemblyObject::instantiate_module(Wasm::Module con
if (import_or_error.is_error())
break;
auto import_ = import_or_error.release_value();
- import_name.type.visit(
- [&](Wasm::TypeIndex index) {
+ TRY(import_name.type.visit(
+ [&](Wasm::TypeIndex index) -> JS::ThrowCompletionOr<void> {
dbgln("Trying to resolve a function {}::{}, type index {}", import_name.module, import_name.name, index.value());
auto& type = module.type(index);
// FIXME: IsCallable()
if (!import_.is_function())
- return;
+ return {};
auto& function = import_.as_function();
// FIXME: If this is a function created by create_native_function(),
// just extract its address and resolve to that.
@@ -205,11 +198,11 @@ Result<size_t, JS::Value> WebAssemblyObject::instantiate_module(Wasm::Module con
return Wasm::Result { Vector<Wasm::Value> {} };
if (type.results().size() == 1) {
- auto value = to_webassembly_value(global_object, result_or_error.release_value(), type.results().first());
- if (!value.has_value())
+ auto value_or_error = to_webassembly_value(global_object, result_or_error.release_value(), type.results().first());
+ if (value_or_error.is_error())
return Wasm::Trap {};
- return Wasm::Result { Vector<Wasm::Value> { value.release_value() } };
+ return Wasm::Result { Vector<Wasm::Value> { value_or_error.release_value() } };
}
// FIXME: Multiple returns
@@ -223,67 +216,57 @@ Result<size_t, JS::Value> WebAssemblyObject::instantiate_module(Wasm::Module con
VERIFY(address.has_value());
resolved_imports.set(import_name, Wasm::ExternValue { Wasm::FunctionAddress { *address } });
+ return {};
},
- [&](Wasm::GlobalType const& type) {
+ [&](Wasm::GlobalType const& type) -> JS::ThrowCompletionOr<void> {
Optional<Wasm::GlobalAddress> address;
// https://webassembly.github.io/spec/js-api/#read-the-imports step 5.1
if (import_.is_number() || import_.is_bigint()) {
if (import_.is_number() && type.type().kind() == Wasm::ValueType::I64) {
// FIXME: Throw a LinkError instead.
- vm.throw_exception<JS::TypeError>(global_object, "LinkError: Import resolution attempted to cast a Number to a BigInteger");
- return;
+ return vm.throw_completion<JS::TypeError>(global_object, "LinkError: Import resolution attempted to cast a Number to a BigInteger");
}
if (import_.is_bigint() && type.type().kind() != Wasm::ValueType::I64) {
// FIXME: Throw a LinkError instead.
- vm.throw_exception<JS::TypeError>(global_object, "LinkError: Import resolution attempted to cast a BigInteger to a Number");
- return;
+ return vm.throw_completion<JS::TypeError>(global_object, "LinkError: Import resolution attempted to cast a BigInteger to a Number");
}
- auto cast_value = to_webassembly_value(global_object, import_, type.type());
- if (!cast_value.has_value())
- return;
- address = s_abstract_machine.store().allocate({ type.type(), false }, cast_value.release_value());
+ auto cast_value = TRY(to_webassembly_value(global_object, import_, type.type()));
+ address = s_abstract_machine.store().allocate({ type.type(), false }, cast_value);
} else {
// FIXME: https://webassembly.github.io/spec/js-api/#read-the-imports step 5.2
// if v implements Global
// let globaladdr be v.[[Global]]
// FIXME: Throw a LinkError instead
- vm.throw_exception<JS::TypeError>(global_object, "LinkError: Invalid value for global type");
- return;
+ return vm.throw_completion<JS::TypeError>(global_object, "LinkError: Invalid value for global type");
}
resolved_imports.set(import_name, Wasm::ExternValue { *address });
+ return {};
},
- [&](Wasm::MemoryType const&) {
+ [&](Wasm::MemoryType const&) -> JS::ThrowCompletionOr<void> {
if (!import_.is_object() || !is<WebAssemblyMemoryObject>(import_.as_object())) {
// FIXME: Throw a LinkError instead
- vm.throw_exception<JS::TypeError>(global_object, "LinkError: Expected an instance of WebAssembly.Memory for a memory import");
- return;
+ return vm.throw_completion<JS::TypeError>(global_object, "LinkError: Expected an instance of WebAssembly.Memory for a memory import");
}
auto address = static_cast<WebAssemblyMemoryObject const&>(import_.as_object()).address();
resolved_imports.set(import_name, Wasm::ExternValue { address });
+ return {};
},
- [&](Wasm::TableType const&) {
+ [&](Wasm::TableType const&) -> JS::ThrowCompletionOr<void> {
if (!import_.is_object() || !is<WebAssemblyTableObject>(import_.as_object())) {
// FIXME: Throw a LinkError instead
- vm.throw_exception<JS::TypeError>(global_object, "LinkError: Expected an instance of WebAssembly.Table for a table import");
- return;
+ return vm.throw_completion<JS::TypeError>(global_object, "LinkError: Expected an instance of WebAssembly.Table for a table import");
}
auto address = static_cast<WebAssemblyTableObject const&>(import_.as_object()).address();
resolved_imports.set(import_name, Wasm::ExternValue { address });
+ return {};
},
- [&](const auto&) {
+ [&](const auto&) -> JS::ThrowCompletionOr<void> {
// FIXME: Implement these.
dbgln("Unimplemented import of non-function attempted");
- vm.throw_exception<JS::TypeError>(global_object, "LinkError: Not Implemented");
- });
- if (vm.exception())
- break;
- }
-
- if (auto exception = vm.exception()) {
- vm.clear_exception();
- return exception->value();
+ return vm.throw_completion<JS::TypeError>(global_object, "LinkError: Not Implemented");
+ }));
}
}
@@ -294,13 +277,13 @@ Result<size_t, JS::Value> WebAssemblyObject::instantiate_module(Wasm::Module con
StringBuilder builder;
builder.append("LinkError: Missing ");
builder.join(' ', link_result.error().missing_imports);
- return JS::Value(JS::TypeError::create(global_object, builder.build()));
+ return vm.throw_completion<JS::TypeError>(global_object, builder.build());
}
auto instance_result = s_abstract_machine.instantiate(module, link_result.release_value());
if (instance_result.is_error()) {
// FIXME: Throw a LinkError instead.
- return JS::Value(JS::TypeError::create(global_object, instance_result.error().error));
+ return vm.throw_completion<JS::TypeError>(global_object, instance_result.error().error);
}
s_instantiated_modules.append(instance_result.release_value());
@@ -327,10 +310,10 @@ JS_DEFINE_OLD_NATIVE_FUNCTION(WebAssemblyObject::instantiate)
if (is<JS::ArrayBuffer>(buffer) || is<JS::TypedArrayBase>(buffer)) {
auto result = parse_module(global_object, buffer);
if (result.is_error()) {
- promise->reject(result.error());
+ promise->reject(result.release_error().value());
return promise;
}
- module = &WebAssemblyObject::s_compiled_modules.at(result.value()).module;
+ module = &WebAssemblyObject::s_compiled_modules.at(result.release_value()).module;
should_return_module = true;
} else if (is<WebAssemblyModuleObject>(buffer)) {
module = &static_cast<WebAssemblyModuleObject*>(buffer)->module();
@@ -343,9 +326,9 @@ JS_DEFINE_OLD_NATIVE_FUNCTION(WebAssemblyObject::instantiate)
auto result = instantiate_module(*module, vm, global_object);
if (result.is_error()) {
- promise->reject(result.release_error());
+ promise->reject(result.release_error().value());
} else {
- auto instance_object = vm.heap().allocate<WebAssemblyInstanceObject>(global_object, global_object, result.value());
+ auto instance_object = vm.heap().allocate<WebAssemblyInstanceObject>(global_object, global_object, result.release_value());
if (should_return_module) {
auto object = JS::Object::create(global_object, nullptr);
object->define_direct_property("module", vm.heap().allocate<WebAssemblyModuleObject>(global_object, global_object, s_compiled_modules.size() - 1), JS::default_attributes);
@@ -381,14 +364,14 @@ JS::Value to_js_value(JS::GlobalObject& global_object, Wasm::Value& wasm_value)
VERIFY_NOT_REACHED();
}
-Optional<Wasm::Value> to_webassembly_value(JS::GlobalObject& global_object, JS::Value value, const Wasm::ValueType& type)
+JS::ThrowCompletionOr<Wasm::Value> to_webassembly_value(JS::GlobalObject& global_object, JS::Value value, const Wasm::ValueType& type)
{
static ::Crypto::SignedBigInteger two_64 = "1"_sbigint.shift_left(64);
auto& vm = global_object.vm();
switch (type.kind()) {
case Wasm::ValueType::I64: {
- auto bigint = TRY_OR_DISCARD(value.to_bigint(global_object));
+ auto bigint = TRY(value.to_bigint(global_object));
auto value = bigint->big_integer().divided_by(two_64).remainder;
VERIFY(value.unsigned_value().trimmed_length() <= 2);
i64 integer = static_cast<i64>(value.unsigned_value().to_u64());
@@ -397,15 +380,15 @@ Optional<Wasm::Value> to_webassembly_value(JS::GlobalObject& global_object, JS::
return Wasm::Value { integer };
}
case Wasm::ValueType::I32: {
- auto _i32 = TRY_OR_DISCARD(value.to_i32(global_object));
+ auto _i32 = TRY(value.to_i32(global_object));
return Wasm::Value { static_cast<i32>(_i32) };
}
case Wasm::ValueType::F64: {
- auto number = TRY_OR_DISCARD(value.to_double(global_object));
+ auto number = TRY(value.to_double(global_object));
return Wasm::Value { static_cast<double>(number) };
}
case Wasm::ValueType::F32: {
- auto number = TRY_OR_DISCARD(value.to_double(global_object));
+ auto number = TRY(value.to_double(global_object));
return Wasm::Value { static_cast<float>(number) };
}
case Wasm::ValueType::FunctionReference:
@@ -421,8 +404,7 @@ Optional<Wasm::Value> to_webassembly_value(JS::GlobalObject& global_object, JS::
}
}
- vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Exported function");
- return {};
+ return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Exported function");
}
case Wasm::ValueType::ExternReference:
case Wasm::ValueType::NullExternReference:
@@ -448,13 +430,8 @@ JS::NativeFunction* create_native_function(JS::GlobalObject& global_object, Wasm
// Grab as many values as needed and convert them.
size_t index = 0;
- for (auto& type : type.parameters()) {
- auto result = to_webassembly_value(global_object, vm.argument(index++), type);
- if (result.has_value())
- values.append(result.release_value());
- else
- return JS::throw_completion(vm.exception()->value());
- }
+ for (auto& type : type.parameters())
+ values.append(TRY(to_webassembly_value(global_object, vm.argument(index++), type)));
auto result = WebAssemblyObject::s_abstract_machine.invoke(address, move(values));
// FIXME: Use the convoluted mapping of errors defined in the spec.
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.h b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.h
index 6f243da67b..a421643973 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.h
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.h
@@ -14,10 +14,10 @@
namespace Web::Bindings {
class WebAssemblyMemoryObject;
-Result<size_t, JS::Value> parse_module(JS::GlobalObject& global_object, JS::Object* buffer);
+JS::ThrowCompletionOr<size_t> parse_module(JS::GlobalObject& global_object, JS::Object* buffer);
JS::NativeFunction* create_native_function(JS::GlobalObject& global_object, Wasm::FunctionAddress address, String const& name);
JS::Value to_js_value(JS::GlobalObject& global_object, Wasm::Value& wasm_value);
-Optional<Wasm::Value> to_webassembly_value(JS::GlobalObject& global_object, JS::Value value, const Wasm::ValueType& type);
+JS::ThrowCompletionOr<Wasm::Value> to_webassembly_value(JS::GlobalObject& global_object, JS::Value value, const Wasm::ValueType& type);
class WebAssemblyObject final : public JS::Object {
JS_OBJECT(WebAssemblyObject, JS::Object);
@@ -29,7 +29,7 @@ public:
virtual void visit_edges(Cell::Visitor&) override;
- static Result<size_t, JS::Value> instantiate_module(Wasm::Module const&, JS::VM&, JS::GlobalObject&);
+ static JS::ThrowCompletionOr<size_t> instantiate_module(Wasm::Module const&, JS::VM&, JS::GlobalObject&);
struct CompiledWebAssemblyModule {
explicit CompiledWebAssemblyModule(Wasm::Module&& module)
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTableConstructor.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTableConstructor.cpp
index e5d09f8505..9a56853374 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTableConstructor.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTableConstructor.cpp
@@ -62,17 +62,14 @@ JS::ThrowCompletionOr<JS::Object*> WebAssemblyTableConstructor::construct(Functi
return vm.throw_completion<JS::RangeError>(global_object, "maximum should be larger than or equal to initial");
auto value_value = TRY(descriptor->get("value"));
- auto reference_value = [&]() -> Optional<Wasm::Value> {
+ auto reference_value = TRY([&]() -> JS::ThrowCompletionOr<Wasm::Value> {
if (value_value.is_undefined())
return Wasm::Value(*reference_type, 0ull);
return to_webassembly_value(global_object, value_value, *reference_type);
- }();
+ }());
- if (auto* exception = vm.exception())
- return JS::throw_completion(exception->value());
-
- auto& reference = reference_value->value().get<Wasm::Reference>();
+ auto& reference = reference_value.value().get<Wasm::Reference>();
auto address = WebAssemblyObject::s_abstract_machine.store().allocate(Wasm::TableType { *reference_type, Wasm::Limits { initial, maximum } });
if (!address.has_value())
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTablePrototype.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTablePrototype.cpp
index f5b66f8bf3..c65f959a62 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTablePrototype.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssemblyTablePrototype.cpp
@@ -36,17 +36,14 @@ JS_DEFINE_OLD_NATIVE_FUNCTION(WebAssemblyTablePrototype::grow)
auto initial_size = table->elements().size();
auto value_value = vm.argument(1);
- auto reference_value = [&]() -> Optional<Wasm::Value> {
+ auto reference_value = TRY_OR_DISCARD([&]() -> JS::ThrowCompletionOr<Wasm::Value> {
if (value_value.is_undefined())
return Wasm::Value(table->type().element_type(), 0ull);
return to_webassembly_value(global_object, value_value, table->type().element_type());
- }();
+ }());
- if (!reference_value.has_value())
- return {};
-
- auto& reference = reference_value->value().get<Wasm::Reference>();
+ auto& reference = reference_value.value().get<Wasm::Reference>();
if (!table->grow(delta, reference)) {
vm.throw_exception<JS::RangeError>(global_object, "Failed to grow table");
@@ -105,17 +102,14 @@ JS_DEFINE_OLD_NATIVE_FUNCTION(WebAssemblyTablePrototype::set)
}
auto value_value = vm.argument(1);
- auto reference_value = [&]() -> Optional<Wasm::Value> {
+ auto reference_value = TRY_OR_DISCARD([&]() -> JS::ThrowCompletionOr<Wasm::Value> {
if (value_value.is_undefined())
return Wasm::Value(table->type().element_type(), 0ull);
return to_webassembly_value(global_object, value_value, table->type().element_type());
- }();
-
- if (!reference_value.has_value())
- return {};
+ }());
- auto& reference = reference_value->value().get<Wasm::Reference>();
+ auto& reference = reference_value.value().get<Wasm::Reference>();
table->elements()[index] = reference;
return JS::js_undefined();