RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 11:18:11 +00:00
Code Issues Activity Actions

LibJS/Bytecode: Use proper this for receiver in get/set for super expr

Browse source 
Summary:
    Diff Tests:
        +14 ✅    -2 ❌    -12 📝
This commit is contained in:
Luke Wilde 2023-07-02 19:26:31 +01:00 • committed by Andreas Kling
parent b7d23162cc
commit b271d9a6bf
6 changed files with 323 additions and 38 deletions
Download patch file Download diff file Expand all files Collapse all files

49
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
View file

@ -377,13 +377,30 @@ Bytecode::CodeGenerationErrorOr<void> AssignmentExpression::generate_bytecode(By
// b. ReturnIfAbrupt(lref).
Optional<Bytecode::Register> base_object_register;
Optional<Bytecode::Register> computed_property_register;
Optional<Bytecode::Register> this_value_register;
bool lhs_is_super_expression = false;
if (is<MemberExpression>(*lhs)) {
auto& expression = static_cast<MemberExpression const&>(*lhs);
TRY(expression.object().generate_bytecode(generator));
lhs_is_super_expression = is<SuperExpression>(expression.object());
base_object_register = generator.allocate_register();
generator.emit<Bytecode::Op::Store>(*base_object_register);
if (!lhs_is_super_expression) {
TRY(expression.object().generate_bytecode(generator));
generator.emit<Bytecode::Op::Store>(*base_object_register);
} else {
// https://tc39.es/ecma262/#sec-super-keyword-runtime-semantics-evaluation
// 1. Let env be GetThisEnvironment().
// 2. Let actualThis be ? env.GetThisBinding().
this_value_register = generator.allocate_register();
generator.emit<Bytecode::Op::ResolveThisBinding>();
generator.emit<Bytecode::Op::Store>(*this_value_register);
// SuperProperty : super [ Expression ]
// 3. Let propertyNameReference be ? Evaluation of Expression.
// 4. Let propertyNameValue be ? GetValue(propertyNameReference).
}
if (expression.is_computed()) {
TRY(expression.property().generate_bytecode(generator));
@ -401,6 +418,18 @@ Bytecode::CodeGenerationErrorOr<void> AssignmentExpression::generate_bytecode(By
"Unimplemented non-computed member expression"sv
};
}
if (lhs_is_super_expression) {
// 5/7. Return ? MakeSuperPropertyReference(actualThis, propertyKey, strict).
// https://tc39.es/ecma262/#sec-makesuperpropertyreference
// 1. Let env be GetThisEnvironment().
// 2. Assert: env.HasSuperBinding() is true.
// 3. Let baseValue be ? env.GetSuperBase().
// 4. Return the Reference Record { [[Base]]: baseValue, [[ReferencedName]]: propertyKey, [[Strict]]: strict, [[ThisValue]]: actualThis }.
generator.emit<Bytecode::Op::ResolveSuperBase>();
generator.emit<Bytecode::Op::Store>(*base_object_register);
}
} else if (is<Identifier>(*lhs)) {
// NOTE: For Identifiers, we cannot perform GetVariable and then write into the reference it retrieves, only SetVariable can do this.
// FIXME: However, this breaks spec as we are doing variable lookup after evaluating the RHS. This is observable in an object environment, where we visibly perform HasOwnProperty and Get(@@unscopables) on the binded object.
@ -428,10 +457,16 @@ Bytecode::CodeGenerationErrorOr<void> AssignmentExpression::generate_bytecode(By
auto& expression = static_cast<MemberExpression const&>(*lhs);
if (expression.is_computed()) {
generator.emit<Bytecode::Op::PutByValue>(*base_object_register, *computed_property_register);
if (!lhs_is_super_expression)
generator.emit<Bytecode::Op::PutByValue>(*base_object_register, *computed_property_register);
else
generator.emit<Bytecode::Op::PutByValueWithThis>(*base_object_register, *computed_property_register, *this_value_register);
} else if (expression.property().is_identifier()) {
auto identifier_table_ref = generator.intern_identifier(verify_cast<Identifier>(expression.property()).string());
generator.emit<Bytecode::Op::PutById>(*base_object_register, identifier_table_ref);
if (!lhs_is_super_expression)
generator.emit<Bytecode::Op::PutById>(*base_object_register, identifier_table_ref);
else
generator.emit<Bytecode::Op::PutByIdWithThis>(*base_object_register, *this_value_register, identifier_table_ref);
} else if (expression.property().is_private_identifier()) {
auto identifier_table_ref = generator.intern_identifier(verify_cast<PrivateIdentifier>(expression.property()).string());
generator.emit<Bytecode::Op::PutPrivateById>(*base_object_register, identifier_table_ref);
@ -1435,11 +1470,11 @@ static Bytecode::CodeGenerationErrorOr<void> get_base_and_value_from_member_expr
auto super_base_register = generator.allocate_register();
generator.emit<Bytecode::Op::Store>(super_base_register);
generator.emit<Bytecode::Op::Load>(*computed_property_value_register);
generator.emit<Bytecode::Op::GetByValue>(super_base_register);
generator.emit<Bytecode::Op::GetByValueWithThis>(super_base_register, this_reg);
} else {
// 3. Let propertyKey be StringValue of IdentifierName.
auto identifier_table_ref = generator.intern_identifier(verify_cast<Identifier>(member_expression.property()).string());
generator.emit<Bytecode::Op::GetById>(identifier_table_ref);
generator.emit<Bytecode::Op::GetByIdWithThis>(identifier_table_ref, this_reg);
}
} else {
TRY(member_expression.object().generate_bytecode(generator));