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LibJS: Partially revert 12b283f

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This commit partially reverts "LibJS: Make accessing the current
function's arguments cheaper".
While the change passed all the currently passing test262 tests, it
seems to have _some_ flaw that silently breaks with some real-world
websites.
As the speedup with negligible at best, let's just revert it until we
can implement it more correctly.
This commit is contained in:
Ali Mohammad Pur 2021-10-08 19:56:02 +03:30
parent fa6c06ce8d
commit 13138811df
Notes: sideshowbarker 2024-07-18 02:55:35 +09:00
4 changed files with 0 additions and 107 deletions
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18
Userland/Libraries/LibJS/AST.cpp
View file

@ -1012,28 +1012,10 @@ Reference Identifier::to_reference(Interpreter& interpreter, GlobalObject&) cons
VERIFY(environment);
VERIFY(environment->is_declarative_environment());
if (!environment->is_permanently_screwed_by_eval()) {
if (m_lexically_bound_function_argument.has_value()) {
return Reference {
*environment,
string(),
*m_lexically_bound_function_argument,
interpreter.vm().in_strict_mode(),
m_cached_environment_coordinate,
&interpreter.vm().running_execution_context(),
};
}
return Reference { *environment, string(), interpreter.vm().in_strict_mode(), m_cached_environment_coordinate };
}
m_cached_environment_coordinate = {};
}
if (m_lexically_bound_function_argument.has_value()) {
return Reference {
string(),
*m_lexically_bound_function_argument,
interpreter.vm().in_strict_mode(),
&interpreter.vm().running_execution_context(),
};
}
auto reference = interpreter.vm().resolve_binding(string());
if (reference.environment_coordinate().has_value())

24
Userland/Libraries/LibJS/Parser.cpp
View file

@ -1534,30 +1534,6 @@ NonnullRefPtr<Expression> Parser::parse_expression(int min_precedence, Associati
if (identifier_instance->string() == "arguments"sv)
m_state.current_scope_pusher->set_contains_access_to_arguments_object();
}
if (function_scope && has_not_been_declared_as_variable) {
auto& parameters = function_scope->function_parameters();
Optional<size_t> argument_index;
size_t index = 0;
for (auto& parameter : parameters) {
auto current_index = index++;
if (parameter.is_rest)
break;
if (auto name_ptr = parameter.binding.get_pointer<FlyString>()) {
// Need VM assistance for this, so let's just pretend it's not there.
if (parameter.default_value)
break;
if (identifier_instance->string() == *name_ptr) {
argument_index = current_index;
if (m_state.strict_mode)
break;
}
}
}
if (argument_index.has_value())
m_state.current_scope_pusher->associate_identifier_with_argument_index(identifier_instance, *argument_index);
}
}
while (match(TokenType::TemplateLiteralStart)) {

41
Userland/Libraries/LibJS/Runtime/Reference.cpp
View file

@ -48,31 +48,6 @@ void Reference::put_value(GlobalObject& global_object, Value value)
}
VERIFY(m_base_type == BaseType::Environment);
// Note: Optimisation, not from the spec.
if (m_function_argument_index.has_value()) {
// Note: Modifying this binding requires us to sync with the environment.
if (!m_base_environment) {
auto real_reference = global_object.vm().resolve_binding(m_name.as_string(), m_referenced_function_context->lexical_environment);
m_base_environment = real_reference.m_base_environment;
}
if (!global_object.vm().execution_context_stack().is_empty() && m_referenced_function_context == &global_object.vm().running_execution_context()) {
auto& arguments = m_referenced_function_context->arguments;
auto index = m_function_argument_index.value();
if (arguments.size() > index) {
arguments[index] = value;
} else {
arguments.ensure_capacity(index + 1);
for (size_t i = arguments.size(); i < index; ++i)
arguments.append(js_undefined());
arguments.append(value);
}
m_base_environment->set_mutable_binding(global_object, name().as_string(), value, is_strict());
return;
}
}
VERIFY(m_base_environment);
if (m_environment_coordinate.has_value())
static_cast<DeclarativeEnvironment*>(m_base_environment)->set_mutable_binding_direct(global_object, m_environment_coordinate->index, value, m_strict);
@ -106,16 +81,6 @@ Value Reference::get_value(GlobalObject& global_object) const
VERIFY(m_base_type == BaseType::Environment);
// Note: Optimisation, not from the spec.
if (m_function_argument_index.has_value()) {
if (!global_object.vm().execution_context_stack().is_empty() && m_referenced_function_context == &global_object.vm().running_execution_context())
return global_object.vm().argument(m_function_argument_index.value());
if (!m_base_environment) {
auto real_reference = global_object.vm().resolve_binding(m_name.as_string(), m_referenced_function_context->lexical_environment);
m_base_environment = real_reference.m_base_environment;
}
}
VERIFY(m_base_environment);
if (m_environment_coordinate.has_value())
return static_cast<DeclarativeEnvironment*>(m_base_environment)->get_binding_value_direct(global_object, m_environment_coordinate->index, m_strict);
@ -177,12 +142,6 @@ bool Reference::delete_(GlobalObject& global_object)
VERIFY(m_base_type == BaseType::Environment);
// Note: Optimisation, not from the spec.
if (m_function_argument_index.has_value()) {
// This is a direct reference to a function argument.
return false;
}
// c. Return ? base.DeleteBinding(ref.[[ReferencedName]]).
return m_base_environment->delete_binding(global_object, m_name.as_string());
}

24
Userland/Libraries/LibJS/Runtime/Reference.h
View file

@ -55,28 +55,6 @@ public:
{
}
Reference(FlyString referenced_name, size_t function_argument_index, bool strict = false, ExecutionContext* function_context = nullptr)
: m_base_type(BaseType::Environment)
, m_base_environment(nullptr)
, m_name(move(referenced_name))
, m_strict(strict)
, m_environment_coordinate({})
, m_function_argument_index(function_argument_index)
, m_referenced_function_context(function_context)
{
}
Reference(Environment& base, FlyString referenced_name, size_t function_argument_index, bool strict = false, Optional<EnvironmentCoordinate> environment_coordinate = {}, ExecutionContext* function_context = nullptr)
: m_base_type(BaseType::Environment)
, m_base_environment(&base)
, m_name(move(referenced_name))
, m_strict(strict)
, m_environment_coordinate(move(environment_coordinate))
, m_function_argument_index(function_argument_index)
, m_referenced_function_context(function_context)
{
}
Value base() const
{
VERIFY(m_base_type == BaseType::Value);
@ -157,8 +135,6 @@ private:
Value m_this_value;
bool m_strict { false };
Optional<EnvironmentCoordinate> m_environment_coordinate;
Optional<size_t> m_function_argument_index;
ExecutionContext* m_referenced_function_context { nullptr };
};
}