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https://github.com/RGBCube/serenity
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LibJS: Convert ScopeNode declaration functions to ThrowCompletionOr
This removes a number of vm.exception() checks which are now caught
directly by TRY. Make use of these checks in
{Global, Eval}DeclarationInstantiation and while we're here add spec
comments.
This commit is contained in:
davidot
Linus Groh
parent
cc7a117f0f
commit
4136cbdb09
6 changed files with 462 additions and 305 deletions
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@ -598,195 +598,310 @@ ThrowCompletionOr<Value> perform_eval(Value x, GlobalObject& caller_realm, Calle
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// 19.2.1.3 EvalDeclarationInstantiation ( body, varEnv, lexEnv, privateEnv, strict ), https://tc39.es/ecma262/#sec-evaldeclarationinstantiation
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ThrowCompletionOr<void> eval_declaration_instantiation(VM& vm, GlobalObject& global_object, Program const& program, Environment* variable_environment, Environment* lexical_environment, PrivateEnvironment* private_environment, bool strict)
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{
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// FIXME: I'm not sure if the global object is correct here. And this is quite a crucial spot!
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GlobalEnvironment* global_var_environment = variable_environment->is_global_environment() ? static_cast<GlobalEnvironment*>(variable_environment) : nullptr;
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// 1. Let varNames be the VarDeclaredNames of body.
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// 2. Let varDeclarations be the VarScopedDeclarations of body.
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// 3. If strict is false, then
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if (!strict) {
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// a. If varEnv is a global Environment Record, then
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if (global_var_environment) {
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program.for_each_var_declared_name([&](auto const& name) {
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if (global_var_environment->has_lexical_declaration(name)) {
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vm.throw_exception<SyntaxError>(global_object, ErrorType::TopLevelVariableAlreadyDeclared, name);
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return IterationDecision::Break;
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}
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return IterationDecision::Continue;
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});
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// i. For each element name of varNames, do
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TRY(program.for_each_var_declared_name([&](auto const& name) -> ThrowCompletionOr<void> {
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// 1. If varEnv.HasLexicalDeclaration(name) is true, throw a SyntaxError exception.
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if (global_var_environment->has_lexical_declaration(name))
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return vm.throw_completion<SyntaxError>(global_object, ErrorType::TopLevelVariableAlreadyDeclared, name);
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// 2. NOTE: eval will not create a global var declaration that would be shadowed by a global lexical declaration.
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return {};
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}));
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}
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// b. Let thisEnv be lexEnv.
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auto* this_environment = lexical_environment;
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// c. Assert: The following loop will terminate.
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// d. Repeat, while thisEnv is not the same as varEnv,
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while (this_environment != variable_environment) {
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// i. If thisEnv is not an object Environment Record, then
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if (!is<ObjectEnvironment>(*this_environment)) {
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program.for_each_var_declared_name([&](auto const& name) {
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// 1. NOTE: The environment of with statements cannot contain any lexical declaration so it doesn't need to be checked for var/let hoisting conflicts.
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// 2. For each element name of varNames, do
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TRY(program.for_each_var_declared_name([&](auto const& name) -> ThrowCompletionOr<void> {
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// a. If thisEnv.HasBinding(name) is true, then
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if (MUST(this_environment->has_binding(name))) {
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vm.throw_exception<SyntaxError>(global_object, ErrorType::TopLevelVariableAlreadyDeclared, name);
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return IterationDecision::Break;
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// i. Throw a SyntaxError exception.
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return vm.throw_completion<SyntaxError>(global_object, ErrorType::TopLevelVariableAlreadyDeclared, name);
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// FIXME: ii. NOTE: Annex B.3.4 defines alternate semantics for the above step.
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// In particular it only throw the syntax error if it is not an environment from a catchclause.
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}
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// FIXME: NOTE: Annex B.3.4 defines alternate semantics for the above step.
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// In particular it only throw the syntax error if it is not an environment from a catchclause.
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return IterationDecision::Continue;
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});
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if (auto* exception = vm.exception())
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return throw_completion(exception->value());
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// b. NOTE: A direct eval will not hoist var declaration over a like-named lexical declaration.
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return {};
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}));
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}
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// ii. Set thisEnv to thisEnv.[[OuterEnv]].
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this_environment = this_environment->outer_environment();
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VERIFY(this_environment);
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}
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}
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// 4. Let privateIdentifiers be a new empty List.
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// 5. Let pointer be privateEnv.
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// 6. Repeat, while pointer is not null,
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// a. For each Private Name binding of pointer.[[Names]], do
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// i. If privateIdentifiers does not contain binding.[[Description]], append binding.[[Description]] to privateIdentifiers.
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// b. Set pointer to pointer.[[OuterPrivateEnvironment]].
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// 7. If AllPrivateIdentifiersValid of body with argument privateIdentifiers is false, throw a SyntaxError exception.
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// FIXME: Add Private identifiers check here.
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HashTable<FlyString> declared_function_names;
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// 8. Let functionsToInitialize be a new empty List.
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Vector<FunctionDeclaration const&> functions_to_initialize;
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program.for_each_var_function_declaration_in_reverse_order([&](FunctionDeclaration const& function) {
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// 9. Let declaredFunctionNames be a new empty List.
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HashTable<FlyString> declared_function_names;
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// 10. For each element d of varDeclarations, in reverse List order, do
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TRY(program.for_each_var_function_declaration_in_reverse_order([&](FunctionDeclaration const& function) -> ThrowCompletionOr<void> {
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// a. If d is neither a VariableDeclaration nor a ForBinding nor a BindingIdentifier, then
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// i. Assert: d is either a FunctionDeclaration, a GeneratorDeclaration, an AsyncFunctionDeclaration, or an AsyncGeneratorDeclaration.
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// Note: This is done by for_each_var_function_declaration_in_reverse_order.
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// ii. NOTE: If there are multiple function declarations for the same name, the last declaration is used.
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// iii. Let fn be the sole element of the BoundNames of d.
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// iv. If fn is not an element of declaredFunctionNames, then
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if (declared_function_names.set(function.name()) != AK::HashSetResult::InsertedNewEntry)
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return IterationDecision::Continue;
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return {};
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// 1. If varEnv is a global Environment Record, then
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if (global_var_environment) {
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auto function_definable_or_error = global_var_environment->can_declare_global_function(function.name());
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if (function_definable_or_error.is_error())
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return IterationDecision::Break;
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auto function_definable = function_definable_or_error.release_value();
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// a. Let fnDefinable be ? varEnv.CanDeclareGlobalFunction(fn).
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if (!function_definable) {
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vm.throw_exception<TypeError>(global_object, ErrorType::CannotDeclareGlobalFunction, function.name());
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return IterationDecision::Break;
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}
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auto function_definable = TRY(global_var_environment->can_declare_global_function(function.name()));
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// b. If fnDefinable is false, throw a TypeError exception.
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if (!function_definable)
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return vm.throw_completion<TypeError>(global_object, ErrorType::CannotDeclareGlobalFunction, function.name());
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}
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// 2. Append fn to declaredFunctionNames.
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// Note: Already done in step iv.
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// 3. Insert d as the first element of functionsToInitialize.
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functions_to_initialize.append(function);
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return IterationDecision::Continue;
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});
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if (auto* exception = vm.exception())
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return throw_completion(exception->value());
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return {};
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}));
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// 11. NOTE: Annex B.3.2.3 adds additional steps at this point.
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// B.3.2.3 Changes to EvalDeclarationInstantiation, https://tc39.es/ecma262/#sec-web-compat-evaldeclarationinstantiation
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// 11. If strict is false, then
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if (!strict) {
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// a. Let declaredFunctionOrVarNames be the list-concatenation of declaredFunctionNames and declaredVarNames.
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// The spec here uses 'declaredVarNames' but that has not been declared yet.
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HashTable<FlyString> hoisted_functions;
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program.for_each_function_hoistable_with_annexB_extension([&](FunctionDeclaration& function_declaration) {
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// b. For each FunctionDeclaration f that is directly contained in the StatementList of a Block, CaseClause, or DefaultClause Contained within body, do
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TRY(program.for_each_function_hoistable_with_annexB_extension([&](FunctionDeclaration& function_declaration) -> ThrowCompletionOr<void> {
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// i. Let F be StringValue of the BindingIdentifier of f.
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auto& function_name = function_declaration.name();
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// ii. If replacing the FunctionDeclaration f with a VariableStatement that has F as a BindingIdentifier would not produce any Early Errors for body, then
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// Note: This is checked during parsing and for_each_function_hoistable_with_annexB_extension so it always passes here.
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// 1. Let bindingExists be false.
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// 2. Let thisEnv be lexEnv.
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auto* this_environment = lexical_environment;
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while (this_environment != variable_environment) {
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if (!is<ObjectEnvironment>(*this_environment) && MUST(this_environment->has_binding(function_name)))
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return IterationDecision::Continue;
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// 3. Assert: The following loop will terminate.
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// 4. Repeat, while thisEnv is not the same as varEnv,
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while (this_environment != variable_environment) {
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// a. If thisEnv is not an object Environment Record, then
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if (!is<ObjectEnvironment>(*this_environment)) {
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// i. If thisEnv.HasBinding(F) is true, then
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if (MUST(this_environment->has_binding(function_name))) {
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// i. Let bindingExists be true.
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// Note: When bindingExists is true we skip all the other steps.
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return {};
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}
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}
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// b. Set thisEnv to thisEnv.[[OuterEnv]].
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this_environment = this_environment->outer_environment();
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VERIFY(this_environment);
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}
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// Note: At this point bindingExists is false.
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// 5. If bindingExists is false and varEnv is a global Environment Record, then
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if (global_var_environment) {
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if (global_var_environment->has_lexical_declaration(function_name))
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return IterationDecision::Continue;
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auto var_definable_or_error = global_var_environment->can_declare_global_var(function_name);
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if (var_definable_or_error.is_error())
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return IterationDecision::Break;
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auto var_definable = var_definable_or_error.release_value();
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if (!var_definable)
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return IterationDecision::Continue;
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// a. If varEnv.HasLexicalDeclaration(F) is false, then
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if (!global_var_environment->has_lexical_declaration(function_name)) {
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// i. Let fnDefinable be ? varEnv.CanDeclareGlobalVar(F).
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if (!TRY(global_var_environment->can_declare_global_var(function_name)))
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return {};
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}
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// b. Else,
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else {
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// i. Let fnDefinable be false.
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return {};
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}
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}
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// 6. Else,
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// a. Let fnDefinable be true.
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// Note: At this point fnDefinable is true.
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// 7. If bindingExists is false and fnDefinable is true, then
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// a. If declaredFunctionOrVarNames does not contain F, then
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if (!declared_function_names.contains(function_name) && !hoisted_functions.contains(function_name)) {
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// i. If varEnv is a global Environment Record, then
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if (global_var_environment) {
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auto result = global_var_environment->create_global_var_binding(function_name, true);
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if (result.is_error())
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return IterationDecision::Break;
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} else {
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// i. Perform ? varEnv.CreateGlobalVarBinding(F, true).
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TRY(global_var_environment->create_global_var_binding(function_name, true));
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}
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// ii. Else,
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else {
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// i. Let bindingExists be varEnv.HasBinding(F).
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// ii. If bindingExists is false, then
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if (!MUST(variable_environment->has_binding(function_name))) {
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// i. Perform ! varEnv.CreateMutableBinding(F, true).
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// ii. Perform ! varEnv.InitializeBinding(F, undefined).
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MUST(variable_environment->create_mutable_binding(global_object, function_name, true));
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MUST(variable_environment->initialize_binding(global_object, function_name, js_undefined()));
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}
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}
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hoisted_functions.set(function_name);
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}
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// iii. Append F to declaredFunctionOrVarNames.
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hoisted_functions.set(function_name);
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// b. When the FunctionDeclaration f is evaluated, perform the following steps in place of the FunctionDeclaration Evaluation algorithm provided in 15.2.6:
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// i. Let genv be the running execution context's VariableEnvironment.
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// ii. Let benv be the running execution context's LexicalEnvironment.
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// iii. Let fobj be ! benv.GetBindingValue(F, false).
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// iv. Perform ? genv.SetMutableBinding(F, fobj, false).
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// v. Return NormalCompletion(empty).
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function_declaration.set_should_do_additional_annexB_steps();
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return IterationDecision::Continue;
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});
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if (auto* exception = vm.exception())
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return throw_completion(exception->value());
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return {};
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}));
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}
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// 12. Let declaredVarNames be a new empty List.
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HashTable<FlyString> declared_var_names;
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program.for_each_var_scoped_variable_declaration([&](VariableDeclaration const& declaration) {
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declaration.for_each_bound_name([&](auto const& name) {
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// 13. For each element d of varDeclarations, do
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TRY(program.for_each_var_scoped_variable_declaration([&](VariableDeclaration const& declaration) {
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// a. If d is a VariableDeclaration, a ForBinding, or a BindingIdentifier, then
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// Note: This is handled by for_each_var_scoped_variable_declaration.
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// i. For each String vn of the BoundNames of d, do
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return declaration.for_each_bound_name([&](auto const& name) -> ThrowCompletionOr<void> {
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// 1. If vn is not an element of declaredFunctionNames, then
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if (!declared_function_names.contains(name)) {
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// a. If varEnv is a global Environment Record, then
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if (global_var_environment) {
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auto variable_definable_or_error = global_var_environment->can_declare_global_var(name);
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if (variable_definable_or_error.is_error())
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return IterationDecision::Break;
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auto variable_definable = variable_definable_or_error.release_value();
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if (!variable_definable) {
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vm.throw_exception<TypeError>(global_object, ErrorType::CannotDeclareGlobalVariable, name);
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return IterationDecision::Break;
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}
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// i. Let vnDefinable be ? varEnv.CanDeclareGlobalVar(vn).
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auto variable_definable = TRY(global_var_environment->can_declare_global_var(name));
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// ii. If vnDefinable is false, throw a TypeError exception.
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if (!variable_definable)
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return vm.throw_completion<TypeError>(global_object, ErrorType::CannotDeclareGlobalVariable, name);
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}
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// b. If vn is not an element of declaredVarNames, then
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// i. Append vn to declaredVarNames.
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declared_var_names.set(name);
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}
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return IterationDecision::Continue;
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return {};
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});
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if (vm.exception())
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return IterationDecision::Break;
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return IterationDecision::Continue;
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});
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if (auto* exception = vm.exception())
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return throw_completion(exception->value());
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}));
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// 14. NOTE: No abnormal terminations occur after this algorithm step unless varEnv is a global Environment Record and the global object is a Proxy exotic object.
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program.for_each_lexically_scoped_declaration([&](Declaration const& declaration) {
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declaration.for_each_bound_name([&](auto const& name) {
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if (declaration.is_constant_declaration())
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(void)lexical_environment->create_immutable_binding(global_object, name, true);
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else
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(void)lexical_environment->create_mutable_binding(global_object, name, false);
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if (vm.exception())
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return IterationDecision::Break;
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return IterationDecision::Continue;
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// 15. Let lexDeclarations be the LexicallyScopedDeclarations of body.
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// 16. For each element d of lexDeclarations, do
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TRY(program.for_each_lexically_scoped_declaration([&](Declaration const& declaration) {
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// a. NOTE: Lexically declared names are only instantiated here but not initialized.
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// b. For each element dn of the BoundNames of d, do
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return declaration.for_each_bound_name([&](auto const& name) -> ThrowCompletionOr<void> {
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// i. If IsConstantDeclaration of d is true, then
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if (declaration.is_constant_declaration()) {
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// 1. Perform ? lexEnv.CreateImmutableBinding(dn, true).
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TRY(lexical_environment->create_immutable_binding(global_object, name, true));
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}
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// ii. Else,
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else {
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// 1. Perform ? lexEnv.CreateMutableBinding(dn, false).
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TRY(lexical_environment->create_mutable_binding(global_object, name, false));
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}
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return {};
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});
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if (vm.exception())
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return IterationDecision::Break;
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return IterationDecision::Continue;
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});
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if (auto* exception = vm.exception())
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return throw_completion(exception->value());
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}));
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// 17. For each Parse Node f of functionsToInitialize, do
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for (auto& declaration : functions_to_initialize) {
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// a. Let fn be the sole element of the BoundNames of f.
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// b. Let fo be InstantiateFunctionObject of f with arguments lexEnv and privateEnv.
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auto* function = ECMAScriptFunctionObject::create(global_object, declaration.name(), declaration.source_text(), declaration.body(), declaration.parameters(), declaration.function_length(), lexical_environment, private_environment, declaration.kind(), declaration.is_strict_mode(), declaration.might_need_arguments_object());
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// c. If varEnv is a global Environment Record, then
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if (global_var_environment) {
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// i. Perform ? varEnv.CreateGlobalFunctionBinding(fn, fo, true).
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TRY(global_var_environment->create_global_function_binding(declaration.name(), function, true));
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} else {
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}
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// d. Else,
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else {
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// i. Let bindingExists be varEnv.HasBinding(fn).
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auto binding_exists = MUST(variable_environment->has_binding(declaration.name()));
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// ii. If bindingExists is false, then
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if (!binding_exists) {
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TRY(variable_environment->create_mutable_binding(global_object, declaration.name(), true));
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TRY(variable_environment->initialize_binding(global_object, declaration.name(), function));
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} else {
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TRY(variable_environment->set_mutable_binding(global_object, declaration.name(), function, false));
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// 1. Let status be ! varEnv.CreateMutableBinding(fn, true).
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// 2. Assert: status is not an abrupt completion because of validation preceding step 14.
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MUST(variable_environment->create_mutable_binding(global_object, declaration.name(), true));
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// 3. Perform ! varEnv.InitializeBinding(fn, fo).
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MUST(variable_environment->initialize_binding(global_object, declaration.name(), function));
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}
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// iii. Else,
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else {
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// 1. Perform ! varEnv.SetMutableBinding(fn, fo, false).
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MUST(variable_environment->set_mutable_binding(global_object, declaration.name(), function, false));
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}
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}
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}
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// 18. For each String vn of declaredVarNames, do
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for (auto& var_name : declared_var_names) {
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// a. If varEnv is a global Environment Record, then
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if (global_var_environment) {
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// i. Perform ? varEnv.CreateGlobalVarBinding(vn, true).
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TRY(global_var_environment->create_global_var_binding(var_name, true));
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} else {
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}
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// b. Else,
|
||||
else {
|
||||
// i. Let bindingExists be varEnv.HasBinding(vn).
|
||||
auto binding_exists = MUST(variable_environment->has_binding(var_name));
|
||||
|
||||
// ii. If bindingExists is false, then
|
||||
if (!binding_exists) {
|
||||
TRY(variable_environment->create_mutable_binding(global_object, var_name, true));
|
||||
TRY(variable_environment->initialize_binding(global_object, var_name, js_undefined()));
|
||||
// 1. Let status be ! varEnv.CreateMutableBinding(vn, true).
|
||||
// 2. Assert: status is not an abrupt completion because of validation preceding step 14.
|
||||
MUST(variable_environment->create_mutable_binding(global_object, var_name, true));
|
||||
|
||||
// 3. Perform ! varEnv.InitializeBinding(vn, undefined).
|
||||
MUST(variable_environment->initialize_binding(global_object, var_name, js_undefined()));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// 19. Return NormalCompletion(empty).
|
||||
return {};
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue