ladybird/Userland/Libraries/LibJS/Bytecode/CommonImplementations.cpp

312 lines
14 KiB
C++

/*
* Copyright (c) 2021-2023, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Bytecode/CommonImplementations.h>
#include <LibJS/Bytecode/Interpreter.h>
#include <LibJS/Bytecode/Op.h>
#include <LibJS/Runtime/DeclarativeEnvironment.h>
#include <LibJS/Runtime/ECMAScriptFunctionObject.h>
#include <LibJS/Runtime/GlobalEnvironment.h>
#include <LibJS/Runtime/ObjectEnvironment.h>
namespace JS::Bytecode {
ThrowCompletionOr<NonnullGCPtr<Object>> base_object_for_get(Bytecode::Interpreter& interpreter, Value base_value)
{
auto& vm = interpreter.vm();
if (base_value.is_object())
return base_value.as_object();
// OPTIMIZATION: For various primitives we can avoid actually creating a new object for them.
if (base_value.is_string())
return vm.current_realm()->intrinsics().string_prototype();
if (base_value.is_number())
return vm.current_realm()->intrinsics().number_prototype();
if (base_value.is_boolean())
return vm.current_realm()->intrinsics().boolean_prototype();
return base_value.to_object(vm);
}
ThrowCompletionOr<Value> get_by_id(Bytecode::Interpreter& interpreter, IdentifierTableIndex property, Value base_value, Value this_value, u32 cache_index)
{
auto& vm = interpreter.vm();
auto const& name = interpreter.current_executable().get_identifier(property);
auto& cache = interpreter.current_executable().property_lookup_caches[cache_index];
if (base_value.is_string()) {
auto string_value = TRY(base_value.as_string().get(vm, name));
if (string_value.has_value())
return *string_value;
}
auto base_obj = TRY(base_object_for_get(interpreter, base_value));
// OPTIMIZATION: If the shape of the object hasn't changed, we can use the cached property offset.
// NOTE: Unique shapes don't change identity, so we compare their serial numbers instead.
auto& shape = base_obj->shape();
if (&shape == cache.shape
&& (!shape.is_unique() || shape.unique_shape_serial_number() == cache.unique_shape_serial_number)) {
return base_obj->get_direct(cache.property_offset.value());
}
CacheablePropertyMetadata cacheable_metadata;
auto value = TRY(base_obj->internal_get(name, this_value, &cacheable_metadata));
if (cacheable_metadata.type == CacheablePropertyMetadata::Type::OwnProperty) {
cache.shape = shape;
cache.property_offset = cacheable_metadata.property_offset.value();
cache.unique_shape_serial_number = shape.unique_shape_serial_number();
}
return value;
}
ThrowCompletionOr<Value> get_by_value(Bytecode::Interpreter& interpreter, Value base_value, Value property_key_value)
{
auto& vm = interpreter.vm();
auto object = TRY(base_object_for_get(interpreter, base_value));
// OPTIMIZATION: Fast path for simple Int32 indexes in array-like objects.
if (property_key_value.is_int32()
&& property_key_value.as_i32() >= 0
&& !object->may_interfere_with_indexed_property_access()
&& object->indexed_properties().has_index(property_key_value.as_i32())) {
auto value = object->indexed_properties().get(property_key_value.as_i32())->value;
if (!value.is_accessor())
return value;
}
auto property_key = TRY(property_key_value.to_property_key(vm));
if (base_value.is_string()) {
auto string_value = TRY(base_value.as_string().get(vm, property_key));
if (string_value.has_value())
return *string_value;
}
return TRY(object->internal_get(property_key, base_value));
}
ThrowCompletionOr<Value> get_global(Bytecode::Interpreter& interpreter, IdentifierTableIndex identifier, u32 cache_index)
{
auto& vm = interpreter.vm();
auto& realm = *vm.current_realm();
auto& cache = interpreter.current_executable().global_variable_caches[cache_index];
auto& binding_object = realm.global_environment().object_record().binding_object();
auto& declarative_record = realm.global_environment().declarative_record();
// OPTIMIZATION: If the shape of the object hasn't changed, we can use the cached property offset.
// NOTE: Unique shapes don't change identity, so we compare their serial numbers instead.
auto& shape = binding_object.shape();
if (cache.environment_serial_number == declarative_record.environment_serial_number()
&& &shape == cache.shape
&& (!shape.is_unique() || shape.unique_shape_serial_number() == cache.unique_shape_serial_number)) {
return binding_object.get_direct(cache.property_offset.value());
}
cache.environment_serial_number = declarative_record.environment_serial_number();
auto const& name = interpreter.current_executable().get_identifier(identifier);
if (vm.running_execution_context().script_or_module.has<NonnullGCPtr<Module>>()) {
// NOTE: GetGlobal is used to access variables stored in the module environment and global environment.
// The module environment is checked first since it precedes the global environment in the environment chain.
auto& module_environment = *vm.running_execution_context().script_or_module.get<NonnullGCPtr<Module>>()->environment();
if (TRY(module_environment.has_binding(name))) {
// TODO: Cache offset of binding value
return TRY(module_environment.get_binding_value(vm, name, vm.in_strict_mode()));
}
}
if (TRY(declarative_record.has_binding(name))) {
// TODO: Cache offset of binding value
return TRY(declarative_record.get_binding_value(vm, name, vm.in_strict_mode()));
}
if (TRY(binding_object.has_property(name))) {
CacheablePropertyMetadata cacheable_metadata;
auto value = TRY(binding_object.internal_get(name, js_undefined(), &cacheable_metadata));
if (cacheable_metadata.type == CacheablePropertyMetadata::Type::OwnProperty) {
cache.shape = shape;
cache.property_offset = cacheable_metadata.property_offset.value();
cache.unique_shape_serial_number = shape.unique_shape_serial_number();
}
return value;
}
return vm.throw_completion<ReferenceError>(ErrorType::UnknownIdentifier, name);
}
ThrowCompletionOr<void> put_by_property_key(VM& vm, Value base, Value this_value, Value value, PropertyKey name, Op::PropertyKind kind)
{
auto object = TRY(base.to_object(vm));
if (kind == Op::PropertyKind::Getter || kind == Op::PropertyKind::Setter) {
// The generator should only pass us functions for getters and setters.
VERIFY(value.is_function());
}
switch (kind) {
case Op::PropertyKind::Getter: {
auto& function = value.as_function();
if (function.name().is_empty() && is<ECMAScriptFunctionObject>(function))
static_cast<ECMAScriptFunctionObject*>(&function)->set_name(DeprecatedString::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))
static_cast<ECMAScriptFunctionObject*>(&function)->set_name(DeprecatedString::formatted("set {}", name));
object->define_direct_accessor(name, nullptr, &function, Attribute::Configurable | Attribute::Enumerable);
break;
}
case Op::PropertyKind::KeyValue: {
bool succeeded = TRY(object->internal_set(name, value, this_value));
if (!succeeded && vm.in_strict_mode())
return vm.throw_completion<TypeError>(ErrorType::ReferenceNullishSetProperty, name, base.to_string_without_side_effects());
break;
}
case Op::PropertyKind::DirectKeyValue:
object->define_direct_property(name, value, Attribute::Enumerable | Attribute::Writable | Attribute::Configurable);
break;
case Op::PropertyKind::Spread:
TRY(object->copy_data_properties(vm, value, {}));
break;
case Op::PropertyKind::ProtoSetter:
if (value.is_object() || value.is_null())
MUST(object->internal_set_prototype_of(value.is_object() ? &value.as_object() : nullptr));
break;
}
return {};
}
ThrowCompletionOr<Value> perform_call(Interpreter& interpreter, Value this_value, Op::CallType call_type, Value callee, MarkedVector<Value> argument_values)
{
auto& vm = interpreter.vm();
auto& function = callee.as_function();
Value return_value;
if (call_type == Op::CallType::DirectEval) {
if (callee == interpreter.realm().intrinsics().eval_function())
return_value = TRY(perform_eval(vm, !argument_values.is_empty() ? argument_values[0].value_or(JS::js_undefined()) : js_undefined(), vm.in_strict_mode() ? CallerMode::Strict : CallerMode::NonStrict, EvalMode::Direct));
else
return_value = TRY(JS::call(vm, function, this_value, move(argument_values)));
} else if (call_type == Op::CallType::Call)
return_value = TRY(JS::call(vm, function, this_value, move(argument_values)));
else
return_value = TRY(construct(vm, function, move(argument_values)));
return return_value;
}
static Completion throw_type_error_for_callee(Bytecode::Interpreter& interpreter, auto& call, StringView callee_type)
{
auto& vm = interpreter.vm();
auto callee = interpreter.reg(call.callee());
if (call.expression_string().has_value())
return vm.throw_completion<TypeError>(ErrorType::IsNotAEvaluatedFrom, callee.to_string_without_side_effects(), callee_type, interpreter.current_executable().get_string(call.expression_string()->value()));
return vm.throw_completion<TypeError>(ErrorType::IsNotA, callee.to_string_without_side_effects(), callee_type);
}
template<typename InstructionType>
ThrowCompletionOr<void> throw_if_needed_for_call(Interpreter& interpreter, InstructionType const& call, Value callee)
{
if (call.call_type() == Op::CallType::Call && !callee.is_function())
return throw_type_error_for_callee(interpreter, call, "function"sv);
if (call.call_type() == Op::CallType::Construct && !callee.is_constructor())
return throw_type_error_for_callee(interpreter, call, "constructor"sv);
return {};
}
template ThrowCompletionOr<void> throw_if_needed_for_call(Interpreter&, Op::Call const&, Value);
template ThrowCompletionOr<void> throw_if_needed_for_call(Interpreter&, Op::CallWithArgumentArray const&, Value);
ThrowCompletionOr<Value> typeof_variable(VM& vm, DeprecatedFlyString const& string)
{
// 1. Let val be the result of evaluating UnaryExpression.
auto reference = TRY(vm.resolve_binding(string));
// 2. If val is a Reference Record, then
// a. If IsUnresolvableReference(val) is true, return "undefined".
if (reference.is_unresolvable())
return PrimitiveString::create(vm, "undefined"_string);
// 3. Set val to ? GetValue(val).
auto value = TRY(reference.get_value(vm));
// 4. NOTE: This step is replaced in section B.3.6.3.
// 5. Return a String according to Table 41.
return PrimitiveString::create(vm, value.typeof());
}
ThrowCompletionOr<void> set_variable(
VM& vm,
DeprecatedFlyString const& name,
Value value,
Op::EnvironmentMode mode,
Op::SetVariable::InitializationMode initialization_mode)
{
auto environment = mode == Op::EnvironmentMode::Lexical ? vm.running_execution_context().lexical_environment : vm.running_execution_context().variable_environment;
auto reference = TRY(vm.resolve_binding(name, environment));
switch (initialization_mode) {
case Op::SetVariable::InitializationMode::Initialize:
TRY(reference.initialize_referenced_binding(vm, value));
break;
case Op::SetVariable::InitializationMode::Set:
TRY(reference.put_value(vm, value));
break;
}
return {};
}
Value new_function(VM& vm, FunctionExpression const& function_node, Optional<IdentifierTableIndex> const& lhs_name, Optional<Register> const& home_object)
{
Value value;
if (!function_node.has_name()) {
DeprecatedFlyString name = {};
if (lhs_name.has_value())
name = vm.bytecode_interpreter().current_executable().get_identifier(lhs_name.value());
value = function_node.instantiate_ordinary_function_expression(vm, name);
} else {
value = ECMAScriptFunctionObject::create(*vm.current_realm(), function_node.name(), function_node.source_text(), function_node.body(), function_node.parameters(), function_node.function_length(), function_node.local_variables_names(), vm.lexical_environment(), vm.running_execution_context().private_environment, function_node.kind(), function_node.is_strict_mode(), function_node.might_need_arguments_object(), function_node.contains_direct_call_to_eval(), function_node.is_arrow_function());
}
if (home_object.has_value()) {
auto home_object_value = vm.bytecode_interpreter().reg(home_object.value());
static_cast<ECMAScriptFunctionObject&>(value.as_function()).set_home_object(&home_object_value.as_object());
}
return value;
}
ThrowCompletionOr<void> put_by_value(VM& vm, Value base, Value property_key_value, Value value, Op::PropertyKind kind)
{
// OPTIMIZATION: Fast path for simple Int32 indexes in array-like objects.
if (base.is_object() && property_key_value.is_int32() && property_key_value.as_i32() >= 0) {
auto& object = base.as_object();
auto* storage = object.indexed_properties().storage();
auto index = static_cast<u32>(property_key_value.as_i32());
if (storage
&& storage->is_simple_storage()
&& !object.may_interfere_with_indexed_property_access()
&& storage->has_index(index)) {
auto existing_value = storage->get(index)->value;
if (!existing_value.is_accessor()) {
storage->put(index, value);
return {};
}
}
}
auto property_key = kind != Op::PropertyKind::Spread ? TRY(property_key_value.to_property_key(vm)) : PropertyKey {};
TRY(put_by_property_key(vm, base, base, value, property_key, kind));
return {};
}
}