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/*
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/AST.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/Reference.h>
namespace JS {
// 6.2.4.6 PutValue ( V, W ), https://tc39.es/ecma262/#sec-putvalue
void Reference::put_value(GlobalObject& global_object, Value value)
{
auto& vm = global_object.vm();
if (is_unresolvable()) {
if (m_strict) {
throw_reference_error(global_object);
return;
}
global_object.put(m_name, value);
return;
}
if (is_property_reference()) {
// FIXME: This is an ad-hoc hack until we support proper variable bindings.
if (!m_base_value.is_object() && vm.in_strict_mode()) {
if (m_base_value.is_nullish())
vm.throw_exception<TypeError>(global_object, ErrorType::ReferenceNullishSetProperty, m_name.to_value(vm).to_string_without_side_effects(), m_base_value.to_string_without_side_effects());
else
vm.throw_exception<TypeError>(global_object, ErrorType::ReferencePrimitiveSetProperty, m_name.to_value(vm).to_string_without_side_effects(), m_base_value.typeof(), m_base_value.to_string_without_side_effects());
return;
}
auto* base_obj = m_base_value.to_object(global_object);
if (!base_obj)
return;
bool succeeded = base_obj->put(m_name, value);
if (!succeeded && m_strict) {
vm.throw_exception<TypeError>(global_object, ErrorType::ReferenceNullishSetProperty, m_name.to_value(vm).to_string_without_side_effects(), m_base_value.to_string_without_side_effects());
return;
}
return;
}
VERIFY(m_base_type == BaseType::Environment);
auto existing_variable = m_base_environment->get_from_environment(m_name.as_string());
Variable variable {
.value = value,
.declaration_kind = existing_variable.has_value() ? existing_variable->declaration_kind : DeclarationKind::Var
};
// FIXME: This is a hack until we support proper variable bindings.
if (variable.declaration_kind == DeclarationKind::Const) {
vm.throw_exception<TypeError>(global_object, ErrorType::InvalidAssignToConst);
return;
}
bool succeeded = m_base_environment->put_into_environment(m_name.as_string(), variable);
if (vm.exception())
return;
if (!succeeded && m_strict) {
// FIXME: This is a hack and will disappear when we support proper variable bindings.
vm.throw_exception<TypeError>(global_object, ErrorType::DescWriteNonWritable, m_name.to_value(vm).to_string_without_side_effects());
return;
}
}
void Reference::throw_reference_error(GlobalObject& global_object)
{
auto& vm = global_object.vm();
if (!m_name.is_valid())
vm.throw_exception<ReferenceError>(global_object, ErrorType::ReferenceUnresolvable);
else
vm.throw_exception<ReferenceError>(global_object, ErrorType::UnknownIdentifier, m_name.to_string_or_symbol().to_display_string());
}
// 6.2.4.5 GetValue ( V ), https://tc39.es/ecma262/#sec-getvalue
Value Reference::get_value(GlobalObject& global_object, bool throw_if_undefined)
{
if (is_unresolvable()) {
throw_reference_error(global_object);
return {};
}
if (is_property_reference()) {
auto* base_obj = m_base_value.to_object(global_object);
if (!base_obj)
return {};
return base_obj->get(m_name).value_or(js_undefined());
}
VERIFY(m_base_type == BaseType::Environment);
auto value = m_base_environment->get_from_environment(m_name.as_string());
if (!value.has_value()) {
if (!throw_if_undefined) {
// FIXME: This is an ad-hoc hack for the `typeof` operator until we support proper variable bindings.
return js_undefined();
}
throw_reference_error(global_object);
return {};
}
return value->value;
}
bool Reference::delete_(GlobalObject& global_object)
{
// 13.5.1.2 Runtime Semantics: Evaluation, https://tc39.es/ecma262/#sec-delete-operator-runtime-semantics-evaluation
// UnaryExpression : delete UnaryExpression
// NOTE: The following steps have already been evaluated by the time we get here:
// 1. Let ref be the result of evaluating UnaryExpression.
// 2. ReturnIfAbrupt(ref).
// 3. If ref is not a Reference Record, return true.
// 4. If IsUnresolvableReference(ref) is true, then
if (is_unresolvable()) {
// a. Assert: ref.[[Strict]] is false.
VERIFY(!m_strict);
// b. Return true.
return true;
}
auto& vm = global_object.vm();
// 5. If IsPropertyReference(ref) is true, then
if (is_property_reference()) {
// a. Assert: ! IsPrivateReference(ref) is false.
// FIXME: We don't have private references yet.
// b. If IsSuperReference(ref) is true, throw a ReferenceError exception.
if (is_super_reference()) {
vm.throw_exception<ReferenceError>(global_object, ErrorType::UnsupportedDeleteSuperProperty);
return false;
}
// c. Let baseObj be ! ToObject(ref.[[Base]]).
auto* base_obj = m_base_value.to_object(global_object);
if (!base_obj)
return false;
// d. Let deleteStatus be ? baseObj.[[Delete]](ref.[[ReferencedName]]).
bool delete_status = base_obj->delete_property(m_name);
// e. If deleteStatus is false and ref.[[Strict]] is true, throw a TypeError exception.
if (!delete_status && m_strict) {
vm.throw_exception<TypeError>(global_object, ErrorType::ReferenceNullishDeleteProperty, m_name.to_value(vm).to_string_without_side_effects(), m_base_value.to_string_without_side_effects());
return false;
}
// f. Return deleteStatus.
return delete_status;
}
// 6. Else,
// a. Let base be ref.[[Base]].
// b. Assert: base is an Environment Record.
VERIFY(m_base_type == BaseType::Environment);
// c. Return ? base.DeleteBinding(ref.[[ReferencedName]]).
// FIXME: This is ad-hoc, we should be calling DeleteBinding.
return m_base_environment->delete_from_environment(m_name.as_string());
}
String Reference::to_string() const
{
StringBuilder builder;
builder.append("Reference { Base=");
switch (m_base_type) {
case BaseType::Unresolvable:
builder.append("Unresolvable");
break;
case BaseType::Environment:
builder.appendff("{}", base_environment().class_name());
break;
case BaseType::Value:
if (m_base_value.is_empty())
builder.append("<empty>");
else
builder.appendff("{}", m_base_value.to_string_without_side_effects());
break;
}
builder.append(", ReferencedName=");
if (!m_name.is_valid())
builder.append("<invalid>");
else if (m_name.is_symbol())
builder.appendff("{}", m_name.as_symbol()->to_string());
else
builder.appendff("{}", m_name.to_string());
builder.appendff(", Strict={}", m_strict);
builder.appendff(", ThisValue=");
if (m_this_value.is_empty())
builder.append("<empty>");
else
builder.appendff("{}", m_this_value.to_string_without_side_effects());
builder.append(" }");
return builder.to_string();
}
}
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