mirrors/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity.git synced 2025-01-24 10:22:05 -05:00
Code Issues Projects Releases Packages Wiki Activity

LibJS: Convert resolve_binding() to ThrowCompletionOr

Browse source 
The spec has a note stating that resolve binding will always return a
reference whose [[ReferencedName]] field is name. However this is not
correct as the underlying method GetIdentifierReference may throw on
env.HasBinding(name) thus it can throw. However, there are some
scenarios where it cannot throw because the reference is known to exist
in that case we use MUST with a comment.
This commit is contained in:
davidot 2021-12-30 14:13:20 +01:00 • committed by Linus Groh
parent dfaa6c910c
commit 676554d3f8
8 changed files with 44 additions and 42 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
Tests/LibJS/test-js.cpp
View file

@ -63,7 +63,7 @@ TESTJS_GLOBAL_FUNCTION(mark_as_garbage, markAsGarbage)
if (!outer_environment.has_value())
return vm.throw_completion<JS::ReferenceError>(global_object, JS::ErrorType::UnknownIdentifier, variable_name.string());
auto reference = vm.resolve_binding(variable_name.string(), outer_environment.value()->lexical_environment);
auto reference = TRY(vm.resolve_binding(variable_name.string(), outer_environment.value()->lexical_environment));
auto value = TRY(reference.get_value(global_object));

6
Userland/Libraries/LibJS/AST.cpp
View file

@ -705,7 +705,7 @@ struct ForInOfHeadState {
if (!destructuring) {
VERIFY(for_declaration.declarations().first().target().has<NonnullRefPtr<Identifier>>());
lhs_reference = interpreter.vm().resolve_binding(for_declaration.declarations().first().target().get<NonnullRefPtr<Identifier>>()->string());
lhs_reference = MUST(interpreter.vm().resolve_binding(for_declaration.declarations().first().target().get<NonnullRefPtr<Identifier>>()->string()));
}
}
@ -764,7 +764,7 @@ static ThrowCompletionOr<ForInOfHeadState> for_in_of_head_execute(Interpreter& i
if (variable.init()) {
VERIFY(variable.target().has<NonnullRefPtr<Identifier>>());
auto& binding_id = variable.target().get<NonnullRefPtr<Identifier>>()->string();
auto reference = interpreter.vm().resolve_binding(binding_id);
auto reference = TRY(interpreter.vm().resolve_binding(binding_id));
if (auto* exception = interpreter.exception())
return throw_completion(exception->value());
@ -1142,7 +1142,7 @@ Reference Identifier::to_reference(Interpreter& interpreter, GlobalObject&) cons
m_cached_environment_coordinate = {};
}
auto reference = interpreter.vm().resolve_binding(string());
auto reference = TRY_OR_DISCARD(interpreter.vm().resolve_binding(string()));
if (reference.environment_coordinate().has_value())
m_cached_environment_coordinate = reference.environment_coordinate();
return reference;

15
Userland/Libraries/LibJS/Bytecode/Op.cpp
View file

@ -252,7 +252,13 @@ void GetVariable::execute_impl(Bytecode::Interpreter& interpreter) const
m_cached_environment_coordinate = {};
}
auto reference = interpreter.vm().resolve_binding(string);
auto reference_or_error = interpreter.vm().resolve_binding(string);
if (reference_or_error.is_throw_completion()) {
interpreter.vm().throw_exception(interpreter.global_object(), reference_or_error.release_error().value());
return Reference {};
}
auto reference = reference_or_error.release_value();
if (reference.environment_coordinate().has_value())
m_cached_environment_coordinate = reference.environment_coordinate();
return reference;
@ -270,10 +276,13 @@ void GetVariable::execute_impl(Bytecode::Interpreter& interpreter) const
void SetVariable::execute_impl(Bytecode::Interpreter& interpreter) const
{
auto& vm = interpreter.vm();
auto reference = vm.resolve_binding(interpreter.current_executable().get_identifier(m_identifier));
if (vm.exception())
auto reference_or_error = vm.resolve_binding(interpreter.current_executable().get_identifier(m_identifier));
if (reference_or_error.is_throw_completion()) {
interpreter.vm().throw_exception(interpreter.global_object(), reference_or_error.release_error().value());
return;
}
auto reference = reference_or_error.release_value();
// TODO: ThrowCompletionOr<void> return
(void)reference.put_value(interpreter.global_object(), interpreter.accumulator());
}

3
Userland/Libraries/LibJS/Runtime/AbstractOperations.cpp
View file

@ -215,7 +215,8 @@ ThrowCompletionOr<void> initialize_bound_name(GlobalObject& global_object, FlySt
// 2. Else,
else {
// a. Let lhs be ResolveBinding(name).
auto lhs = vm.resolve_binding(name);
// NOTE: Although the spec pretends resolve_binding cannot fail it can just not in this case.
auto lhs = MUST(vm.resolve_binding(name));
// b. Return ? PutValue(lhs, value).
return TRY(lhs.put_value(global_object, value));

4
Userland/Libraries/LibJS/Runtime/ECMAScriptFunctionObject.cpp
View file

@ -441,9 +441,7 @@ ThrowCompletionOr<void> ECMAScriptFunctionObject::function_declaration_instantia
Environment* used_environment = has_duplicates ? nullptr : environment;
if constexpr (IsSame<FlyString const&, decltype(param)>) {
Reference reference = vm.resolve_binding(param, used_environment);
if (auto* exception = vm.exception())
return throw_completion(exception->value());
Reference reference = TRY(vm.resolve_binding(param, used_environment));
// Here the difference from hasDuplicates is important
if (has_duplicates)
return reference.put_value(global_object(), argument_value);

50
Userland/Libraries/LibJS/Runtime/VM.cpp
View file

@ -237,7 +237,7 @@ ThrowCompletionOr<void> VM::property_binding_initialization(BindingPattern const
if (property.is_rest) {
Reference assignment_target;
if (auto identifier_ptr = property.name.get_pointer<NonnullRefPtr<Identifier>>()) {
assignment_target = resolve_binding((*identifier_ptr)->string(), environment);
assignment_target = TRY(resolve_binding((*identifier_ptr)->string(), environment));
} else if (auto member_ptr = property.alias.get_pointer<NonnullRefPtr<MemberExpression>>()) {
assignment_target = (*member_ptr)->to_reference(interpreter(), global_object);
} else {
@ -282,9 +282,7 @@ ThrowCompletionOr<void> VM::property_binding_initialization(BindingPattern const
if (property.name.has<NonnullRefPtr<Identifier>>() && property.alias.has<Empty>()) {
// FIXME: this branch and not taking this have a lot in common we might want to unify it more (like it was before).
auto& identifier = *property.name.get<NonnullRefPtr<Identifier>>();
auto reference = resolve_binding(identifier.string(), environment);
if (auto* thrown_exception = exception())
return JS::throw_completion(thrown_exception->value());
auto reference = TRY(resolve_binding(identifier.string(), environment));
auto value_to_assign = TRY(object->get(name));
if (property.initializer && value_to_assign.is_undefined()) {
@ -298,17 +296,15 @@ ThrowCompletionOr<void> VM::property_binding_initialization(BindingPattern const
continue;
}
Optional<Reference> reference_to_assign_to;
property.alias.visit(
[&](Empty) {},
[&](NonnullRefPtr<Identifier> const& identifier) {
reference_to_assign_to = resolve_binding(identifier->string(), environment);
auto reference_to_assign_to = TRY(property.alias.visit(
[&](Empty) -> ThrowCompletionOr<Optional<Reference>> { return Optional<Reference> {}; },
[&](NonnullRefPtr<Identifier> const& identifier) -> ThrowCompletionOr<Optional<Reference>> {
return TRY(resolve_binding(identifier->string(), environment));
},
[&](NonnullRefPtr<BindingPattern> const&) {},
[&](NonnullRefPtr<MemberExpression> const& member_expression) {
reference_to_assign_to = member_expression->to_reference(interpreter(), global_object);
});
[&](NonnullRefPtr<BindingPattern> const&) -> ThrowCompletionOr<Optional<Reference>> { return Optional<Reference> {}; },
[&](NonnullRefPtr<MemberExpression> const& member_expression) -> ThrowCompletionOr<Optional<Reference>> {
return member_expression->to_reference(interpreter(), global_object);
}));
if (auto* thrown_exception = exception())
return JS::throw_completion(thrown_exception->value());
@ -347,19 +343,15 @@ ThrowCompletionOr<void> VM::iterator_binding_initialization(BindingPattern const
auto& entry = binding.entries[i];
Value value;
Optional<Reference> assignment_target;
entry.alias.visit(
[&](Empty) {},
[&](NonnullRefPtr<Identifier> const& identifier) {
assignment_target = resolve_binding(identifier->string(), environment);
auto assignment_target = TRY(entry.alias.visit(
[&](Empty) -> ThrowCompletionOr<Optional<Reference>> { return Optional<Reference> {}; },
[&](NonnullRefPtr<Identifier> const& identifier) -> ThrowCompletionOr<Optional<Reference>> {
return TRY(resolve_binding(identifier->string(), environment));
},
[&](NonnullRefPtr<BindingPattern> const&) {},
[&](NonnullRefPtr<MemberExpression> const& member_expression) {
assignment_target = member_expression->to_reference(interpreter(), global_object);
});
if (auto* thrown_exception = exception())
return JS::throw_completion(thrown_exception->value());
[&](NonnullRefPtr<BindingPattern> const&) -> ThrowCompletionOr<Optional<Reference>> { return Optional<Reference> {}; },
[&](NonnullRefPtr<MemberExpression> const& member_expression) -> ThrowCompletionOr<Optional<Reference>> {
return member_expression->to_reference(interpreter(), global_object);
}));
if (entry.is_rest) {
VERIFY(i == binding.entries.size() - 1);
@ -456,7 +448,7 @@ Reference VM::get_identifier_reference(Environment* environment, FlyString name,
}
// 9.4.2 ResolveBinding ( name [ , env ] ), https://tc39.es/ecma262/#sec-resolvebinding
Reference VM::resolve_binding(FlyString const& name, Environment* environment)
ThrowCompletionOr<Reference> VM::resolve_binding(FlyString const& name, Environment* environment)
{
// 1. If env is not present or if env is undefined, then
if (!environment) {
@ -472,6 +464,10 @@ Reference VM::resolve_binding(FlyString const& name, Environment* environment)
// 4. Return ? GetIdentifierReference(env, name, strict).
return get_identifier_reference(environment, name, strict);
// NOTE: The spec says:
// Note: The result of ResolveBinding is always a Reference Record whose [[ReferencedName]] field is name.
// But this is not actually correct as GetIdentifierReference (or really the methods it calls) can throw.
}
// 7.3.33 InitializeInstanceElements ( O, constructor ), https://tc39.es/ecma262/#sec-initializeinstanceelements

2
Userland/Libraries/LibJS/Runtime/VM.h
View file

@ -192,7 +192,7 @@ public:
ScopeType unwind_until() const { return m_unwind_until; }
FlyString unwind_until_label() const { return m_unwind_until_label; }
Reference resolve_binding(FlyString const&, Environment* = nullptr);
ThrowCompletionOr<Reference> resolve_binding(FlyString const&, Environment* = nullptr);
Reference get_identifier_reference(Environment*, FlyString, bool strict, size_t hops = 0);
template<typename T, typename... Args>

4
Userland/Utilities/js.cpp
View file

@ -1427,9 +1427,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
switch (mode) {
case CompleteProperty: {
Optional<JS::Value> maybe_value;
auto maybe_variable = vm->resolve_binding(variable_name, &global_environment);
if (vm->exception())
break;
auto maybe_variable = TRY_OR_DISCARD(vm->resolve_binding(variable_name, &global_environment));
maybe_value = TRY_OR_DISCARD(maybe_variable.get_value(interpreter->global_object()));
VERIFY(!maybe_value->is_empty());