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LibJS/Bytecode: Leave GlobalDeclarationInstantiation in C++

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Don't try to implement this AO in bytecode. Instead, the bytecode
Interpreter class now has a run() API with the same inputs as the AST
interpreter. It sets up the necessary environments etc, including
invoking the GlobalDeclarationInstantiation AO.
This commit is contained in:
Andreas Kling 2023-06-15 12:36:57 +02:00
parent 32d9c8e3ca
commit d063f35afd
Notes: sideshowbarker 2024-07-18 01:43:16 +09:00
12 changed files with 172 additions and 284 deletions
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177
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
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@ -70,182 +70,7 @@ Bytecode::CodeGenerationErrorOr<void> ScopeNode::generate_bytecode(Bytecode::Gen
return {};
} else if (is<Program>(*this)) {
// Perform the steps of GlobalDeclarationInstantiation.
generator.begin_variable_scope(Bytecode::Generator::BindingMode::Global, Bytecode::Generator::SurroundingScopeKind::Global);
pushed_scope_count++;
// 1. Let lexNames be the LexicallyDeclaredNames of script.
// 2. Let varNames be the VarDeclaredNames of script.
// 3. For each element name of lexNames, do
(void)for_each_lexically_declared_name([&](auto const& name) -> ThrowCompletionOr<void> {
auto identifier = generator.intern_identifier(name);
// a. If env.HasVarDeclaration(name) is true, throw a SyntaxError exception.
// b. If env.HasLexicalDeclaration(name) is true, throw a SyntaxError exception.
if (generator.has_binding(identifier)) {
// FIXME: Throw an actual SyntaxError instance.
generator.emit<Bytecode::Op::NewString>(generator.intern_string(DeprecatedString::formatted("SyntaxError: toplevel variable already declared: {}", name)));
generator.emit<Bytecode::Op::Throw>();
return {};
}
// FIXME: c. If hasRestrictedGlobalProperty is true, throw a SyntaxError exception.
// d. If hasRestrictedGlobal is true, throw a SyntaxError exception.
return {};
});
// 4. For each element name of varNames, do
(void)for_each_var_declared_name([&](auto const& name) -> ThrowCompletionOr<void> {
auto identifier = generator.intern_identifier(name);
// a. If env.HasLexicalDeclaration(name) is true, throw a SyntaxError exception.
if (generator.has_binding(identifier)) {
// FIXME: Throw an actual SyntaxError instance.
generator.emit<Bytecode::Op::NewString>(generator.intern_string(DeprecatedString::formatted("SyntaxError: toplevel variable already declared: {}", name)));
generator.emit<Bytecode::Op::Throw>();
}
return {};
});
// 5. Let varDeclarations be the VarScopedDeclarations of script.
// 6. Let functionsToInitialize be a new empty List.
Vector<FunctionDeclaration const&> functions_to_initialize;
// 7. Let declaredFunctionNames be a new empty List.
HashTable<DeprecatedFlyString> declared_function_names;
// 8. For each element d of varDeclarations, in reverse List order, do
(void)for_each_var_function_declaration_in_reverse_order([&](FunctionDeclaration const& function) -> ThrowCompletionOr<void> {
// a. If d is neither a VariableDeclaration nor a ForBinding nor a BindingIdentifier, then
// i. Assert: d is either a FunctionDeclaration, a GeneratorDeclaration, an AsyncFunctionDeclaration, or an AsyncGeneratorDeclaration.
// Note: This is checked in for_each_var_function_declaration_in_reverse_order.
// ii. NOTE: If there are multiple function declarations for the same name, the last declaration is used.
// iii. Let fn be the sole element of the BoundNames of d.
// iv. If fn is not an element of declaredFunctionNames, then
if (declared_function_names.set(function.name()) != AK::HashSetResult::InsertedNewEntry)
return {};
// FIXME: 1. Let fnDefinable be ? env.CanDeclareGlobalFunction(fn).
// FIXME: 2. If fnDefinable is false, throw a TypeError exception.
// 3. Append fn to declaredFunctionNames.
// Note: Already done in step iv. above.
// 4. Insert d as the first element of functionsToInitialize.
functions_to_initialize.prepend(function);
return {};
});
// 9. Let declaredVarNames be a new empty List.
HashTable<DeprecatedFlyString> declared_var_names;
// 10. For each element d of varDeclarations, do
(void)for_each_var_scoped_variable_declaration([&](Declaration const& declaration) {
// a. If d is a VariableDeclaration, a ForBinding, or a BindingIdentifier, then
// Note: This is done in for_each_var_scoped_variable_declaration.
// i. For each String vn of the BoundNames of d, do
return declaration.for_each_bound_name([&](auto const& name) -> ThrowCompletionOr<void> {
// 1. If vn is not an element of declaredFunctionNames, then
if (declared_function_names.contains(name))
return {};
// FIXME: a. Let vnDefinable be ? env.CanDeclareGlobalVar(vn).
// FIXME: b. If vnDefinable is false, throw a TypeError exception.
// c. If vn is not an element of declaredVarNames, then
// i. Append vn to declaredVarNames.
declared_var_names.set(name);
return {};
});
});
// 11. NOTE: No abnormal terminations occur after this algorithm step if the global object is an ordinary object. However, if the global object is a Proxy exotic object it may exhibit behaviours that cause abnormal terminations in some of the following steps.
// 12. NOTE: Annex B.3.2.2 adds additional steps at this point.
// 12. Let strict be IsStrict of script.
// 13. If strict is false, then
if (!verify_cast<Program>(*this).is_strict_mode()) {
// a. Let declaredFunctionOrVarNames be the list-concatenation of declaredFunctionNames and declaredVarNames.
// b. For each FunctionDeclaration f that is directly contained in the StatementList of a Block, CaseClause, or DefaultClause Contained within script, do
(void)for_each_function_hoistable_with_annexB_extension([&](FunctionDeclaration& function_declaration) {
// i. Let F be StringValue of the BindingIdentifier of f.
auto& function_name = function_declaration.name();
// ii. If replacing the FunctionDeclaration f with a VariableStatement that has F as a BindingIdentifier would not produce any Early Errors for script, then
// Note: This step is already performed during parsing and for_each_function_hoistable_with_annexB_extension so this always passes here.
// 1. If env.HasLexicalDeclaration(F) is false, then
auto index = generator.intern_identifier(function_name);
if (generator.has_binding(index, Bytecode::Generator::BindingMode::Lexical))
return;
// FIXME: a. Let fnDefinable be ? env.CanDeclareGlobalVar(F).
// b. If fnDefinable is true, then
// i. NOTE: A var binding for F is only instantiated here if it is neither a VarDeclaredName nor the name of another FunctionDeclaration.
// ii. If declaredFunctionOrVarNames does not contain F, then
if (!declared_function_names.contains(function_name) && !declared_var_names.contains(function_name)) {
// i. Perform ? env.CreateGlobalVarBinding(F, false).
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Var, false, true);
// ii. Append F to declaredFunctionOrVarNames.
declared_function_names.set(function_name);
}
// iii. When the FunctionDeclaration f is evaluated, perform the following steps in place of the FunctionDeclaration Evaluation algorithm provided in 15.2.6:
// i. Let genv be the running execution context's VariableEnvironment.
// ii. Let benv be the running execution context's LexicalEnvironment.
// iii. Let fobj be ! benv.GetBindingValue(F, false).
// iv. Perform ? genv.SetMutableBinding(F, fobj, false).
// v. Return unused.
function_declaration.set_should_do_additional_annexB_steps();
});
}
// 15. For each element d of lexDeclarations, do
(void)for_each_lexically_scoped_declaration([&](Declaration const& declaration) -> ThrowCompletionOr<void> {
// a. NOTE: Lexically declared names are only instantiated here but not initialized.
// b. For each element dn of the BoundNames of d, do
return declaration.for_each_bound_name([&](auto const& name) -> ThrowCompletionOr<void> {
auto identifier = generator.intern_identifier(name);
// i. If IsConstantDeclaration of d is true, then
generator.register_binding(identifier);
if (declaration.is_constant_declaration()) {
// 1. Perform ? env.CreateImmutableBinding(dn, true).
generator.emit<Bytecode::Op::CreateVariable>(identifier, Bytecode::Op::EnvironmentMode::Lexical, true);
} else {
// ii. Else,
// 1. Perform ? env.CreateMutableBinding(dn, false).
generator.emit<Bytecode::Op::CreateVariable>(identifier, Bytecode::Op::EnvironmentMode::Lexical, false);
}
return {};
});
});
// 16. For each Parse Node f of functionsToInitialize, do
for (auto& function_declaration : functions_to_initialize) {
// FIXME: Do this more correctly.
// a. Let fn be the sole element of the BoundNames of f.
// b. Let fo be InstantiateFunctionObject of f with arguments env and privateEnv.
generator.emit<Bytecode::Op::NewFunction>(function_declaration);
// c. Perform ? env.CreateGlobalFunctionBinding(fn, fo, false).
auto const& name = function_declaration.name();
auto index = generator.intern_identifier(name);
if (!generator.has_binding(index)) {
generator.register_binding(index, Bytecode::Generator::BindingMode::Var);
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Lexical, false);
}
generator.emit<Bytecode::Op::SetVariable>(index, Bytecode::Op::SetVariable::InitializationMode::Initialize);
}
// 17. For each String vn of declaredVarNames, do
for (auto& var_name : declared_var_names) {
// a. Perform ? env.CreateGlobalVarBinding(vn, false).
auto index = generator.intern_identifier(var_name);
generator.register_binding(index, Bytecode::Generator::BindingMode::Var);
generator.emit<Bytecode::Op::CreateVariable>(index, Bytecode::Op::EnvironmentMode::Var, false, true);
}
// GlobalDeclarationInstantiation is handled by the C++ AO.
} else {
// FunctionDeclarationInstantiation is handled by the C++ AO.
}