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LibJS: Handle argument spreading in the bytecode vm

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This commit is contained in:
Hendiadyoin1 2022-09-09 16:05:40 +02:00 • committed by Linus Groh
parent ae52ae8f9f
commit 89408d5f64
2 changed files with 67 additions and 31 deletions
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73
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
View file

@ -522,6 +522,48 @@ Bytecode::CodeGenerationErrorOr<void> Identifier::generate_bytecode(Bytecode::Ge
return {};
}
static Bytecode::CodeGenerationErrorOr<void> arguments_to_array_for_call(Bytecode::Generator& generator, Span<CallExpression::Argument const> arguments)
{
if (arguments.is_empty()) {
generator.emit<Bytecode::Op::NewArray>();
return {};
}
auto first_spread = find_if(arguments.begin(), arguments.end(), [](auto el) { return el.is_spread; });
Bytecode::Register args_start_reg { 0 };
for (auto it = arguments.begin(); it != first_spread; ++it) {
auto reg = generator.allocate_register();
if (args_start_reg.index() == 0)
args_start_reg = reg;
}
u32 i = 0;
for (auto it = arguments.begin(); it != first_spread; ++it, ++i) {
VERIFY(it->is_spread == false);
Bytecode::Register reg { args_start_reg.index() + i };
TRY(it->value->generate_bytecode(generator));
generator.emit<Bytecode::Op::Store>(reg);
}
if (first_spread.index() != 0)
generator.emit_with_extra_register_slots<Bytecode::Op::NewArray>(2u, AK::Array { args_start_reg, Bytecode::Register { args_start_reg.index() + static_cast<u32>(first_spread.index() - 1) } });
else
generator.emit<Bytecode::Op::NewArray>();
if (first_spread != arguments.end()) {
auto array_reg = generator.allocate_register();
generator.emit<Bytecode::Op::Store>(array_reg);
for (auto it = first_spread; it != arguments.end(); ++it) {
TRY(it->value->generate_bytecode(generator));
generator.emit<Bytecode::Op::Append>(array_reg, it->is_spread);
}
generator.emit<Bytecode::Op::Load>(array_reg);
}
return {};
}
Bytecode::CodeGenerationErrorOr<void> SuperCall::generate_bytecode(Bytecode::Generator& generator) const
{
if (m_is_synthetic == IsPartOfSyntheticConstructor::Yes) {
@ -533,21 +575,7 @@ Bytecode::CodeGenerationErrorOr<void> SuperCall::generate_bytecode(Bytecode::Gen
// This generates a single argument, which will be implicitly passed in accumulator
MUST(argument.value->generate_bytecode(generator));
} else {
Vector<Bytecode::Register> argument_registers;
argument_registers.ensure_capacity(m_arguments.size());
for (size_t i = 0; i < m_arguments.size(); ++i) {
auto arg_reg = generator.allocate_register();
argument_registers.unchecked_append(arg_reg);
}
for (size_t i = 0; i < m_arguments.size(); ++i) {
TRY(m_arguments[i].value->generate_bytecode(generator));
generator.emit<Bytecode::Op::Store>(argument_registers[i]);
}
if (!argument_registers.is_empty())
generator.emit_with_extra_register_slots<Bytecode::Op::NewArray>(2, AK::Array { argument_registers.first(), argument_registers.last() });
else
generator.emit<Bytecode::Op::NewArray>();
TRY(arguments_to_array_for_call(generator, m_arguments));
}
generator.emit<Bytecode::Op::SuperCall>(m_is_synthetic == IsPartOfSyntheticConstructor::Yes);
@ -1511,16 +1539,7 @@ Bytecode::CodeGenerationErrorOr<void> CallExpression::generate_bytecode(Bytecode
generator.emit<Bytecode::Op::Store>(callee_reg);
}
// FIXME: We only need to record the first and last register, due to packing everything in an array
Vector<Bytecode::Register> argument_registers;
for (size_t i = 0; i < m_arguments.size(); ++i) {
auto arg_reg = generator.allocate_register();
argument_registers.append(arg_reg);
}
for (size_t i = 0; i < m_arguments.size(); ++i) {
TRY(m_arguments[i].value->generate_bytecode(generator));
generator.emit<Bytecode::Op::Store>(argument_registers[i]);
}
TRY(arguments_to_array_for_call(generator, m_arguments));
Bytecode::Op::Call::CallType call_type;
if (is<NewExpression>(*this)) {
@ -1529,10 +1548,6 @@ Bytecode::CodeGenerationErrorOr<void> CallExpression::generate_bytecode(Bytecode
call_type = Bytecode::Op::Call::CallType::Call;
}
if (!argument_registers.is_empty())
generator.emit_with_extra_register_slots<Bytecode::Op::NewArray>(2, AK::Array { argument_registers.first(), argument_registers.last() });
else
generator.emit<Bytecode::Op::NewArray>();
generator.emit<Bytecode::Op::Call>(call_type, callee_reg, this_reg);
return {};
}

25
Userland/Libraries/LibJS/Bytecode/Op.cpp
View file

@ -184,10 +184,11 @@ ThrowCompletionOr<void> NewArray::execute_impl(Bytecode::Interpreter& interprete
ThrowCompletionOr<void> Append::execute_impl(Bytecode::Interpreter& interpreter) const
{
// Note: This OpCode is used to construct array literals containing at least one spread element,
// Note: This OpCode is used to construct array literals and argument arrays for calls,
// containing at least one spread element,
// Iterating over such a spread element to unpack it has to be visible by
// the user courtesy of
// https://tc39.es/ecma262/#sec-runtime-semantics-arrayaccumulation
// (1) https://tc39.es/ecma262/#sec-runtime-semantics-arrayaccumulation
// SpreadElement : ... AssignmentExpression
// 1. Let spreadRef be ? Evaluation of AssignmentExpression.
// 2. Let spreadObj be ? GetValue(spreadRef).
@ -198,6 +199,26 @@ ThrowCompletionOr<void> Append::execute_impl(Bytecode::Interpreter& interpreter)
// c. Let nextValue be ? IteratorValue(next).
// d. Perform ! CreateDataPropertyOrThrow(array, ! ToString(𝔽(nextIndex)), nextValue).
// e. Set nextIndex to nextIndex + 1.
// (2) https://tc39.es/ecma262/#sec-runtime-semantics-argumentlistevaluation
// ArgumentList : ... AssignmentExpression
// 1. Let list be a new empty List.
// 2. Let spreadRef be ? Evaluation of AssignmentExpression.
// 3. Let spreadObj be ? GetValue(spreadRef).
// 4. Let iteratorRecord be ? GetIterator(spreadObj).
// 5. Repeat,
// a. Let next be ? IteratorStep(iteratorRecord).
// b. If next is false, return list.
// c. Let nextArg be ? IteratorValue(next).
// d. Append nextArg to list.
// ArgumentList : ArgumentList , ... AssignmentExpression
// 1. Let precedingArgs be ? ArgumentListEvaluation of ArgumentList.
// 2. Let spreadRef be ? Evaluation of AssignmentExpression.
// 3. Let iteratorRecord be ? GetIterator(? GetValue(spreadRef)).
// 4. Repeat,
// a. Let next be ? IteratorStep(iteratorRecord).
// b. If next is false, return precedingArgs.
// c. Let nextArg be ? IteratorValue(next).
// d. Append nextArg to precedingArgs.
auto& vm = interpreter.vm();