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LibJS: Implement generator functions (only in bytecode mode)

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This commit is contained in:
Ali Mohammad Pur 2021-06-11 01:38:30 +04:30 • committed by Andreas Kling
parent c53a86a3fe
commit 3234697eca
21 changed files with 407 additions and 34 deletions
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15
Userland/Libraries/LibJS/AST.cpp
View file

@ -259,6 +259,12 @@ Value CallExpression::execute(Interpreter& interpreter, GlobalObject& global_obj
return result;
}
Value YieldExpression::execute(Interpreter&, GlobalObject&) const
{
// This should be transformed to a return.
VERIFY_NOT_REACHED();
}
Value ReturnStatement::execute(Interpreter& interpreter, GlobalObject& global_object) const
{
InterpreterNodeScope node_scope { interpreter, *this };
@ -1151,7 +1157,7 @@ void BindingPattern::dump(int indent) const
void FunctionNode::dump(int indent, const String& class_name) const
{
print_indent(indent);
outln("{} '{}'", class_name, name());
outln("{}{} '{}'", class_name, m_is_generator ? "*" : "", name());
if (!m_parameters.is_empty()) {
print_indent(indent + 1);
outln("(Parameters)");
@ -1193,6 +1199,13 @@ void FunctionExpression::dump(int indent) const
FunctionNode::dump(indent, class_name());
}
void YieldExpression::dump(int indent) const
{
ASTNode::dump(indent);
if (argument())
argument()->dump(indent + 1);
}
void ReturnStatement::dump(int indent) const
{
ASTNode::dump(indent);

31
Userland/Libraries/LibJS/AST.h
View file

@ -227,14 +227,16 @@ public:
const Vector<Parameter>& parameters() const { return m_parameters; };
i32 function_length() const { return m_function_length; }
bool is_strict_mode() const { return m_is_strict_mode; }
bool is_generator() const { return m_is_generator; }
protected:
FunctionNode(const FlyString& name, NonnullRefPtr<Statement> body, Vector<Parameter> parameters, i32 function_length, NonnullRefPtrVector<VariableDeclaration> variables, bool is_strict_mode)
FunctionNode(const FlyString& name, NonnullRefPtr<Statement> body, Vector<Parameter> parameters, i32 function_length, NonnullRefPtrVector<VariableDeclaration> variables, bool is_generator, bool is_strict_mode)
: m_name(name)
, m_body(move(body))
, m_parameters(move(parameters))
, m_variables(move(variables))
, m_function_length(function_length)
, m_is_generator(is_generator)
, m_is_strict_mode(is_strict_mode)
{
}
@ -256,6 +258,7 @@ private:
const Vector<Parameter> m_parameters;
NonnullRefPtrVector<VariableDeclaration> m_variables;
const i32 m_function_length;
bool m_is_generator;
bool m_is_strict_mode;
};
@ -265,9 +268,9 @@ class FunctionDeclaration final
public:
static bool must_have_name() { return true; }
FunctionDeclaration(SourceRange source_range, const FlyString& name, NonnullRefPtr<Statement> body, Vector<Parameter> parameters, i32 function_length, NonnullRefPtrVector<VariableDeclaration> variables, bool is_strict_mode = false)
FunctionDeclaration(SourceRange source_range, const FlyString& name, NonnullRefPtr<Statement> body, Vector<Parameter> parameters, i32 function_length, NonnullRefPtrVector<VariableDeclaration> variables, bool is_generator, bool is_strict_mode = false)
: Declaration(move(source_range))
, FunctionNode(name, move(body), move(parameters), function_length, move(variables), is_strict_mode)
, FunctionNode(name, move(body), move(parameters), function_length, move(variables), is_generator, is_strict_mode)
{
}
@ -282,9 +285,9 @@ class FunctionExpression final
public:
static bool must_have_name() { return false; }
FunctionExpression(SourceRange source_range, const FlyString& name, NonnullRefPtr<Statement> body, Vector<Parameter> parameters, i32 function_length, NonnullRefPtrVector<VariableDeclaration> variables, bool is_strict_mode, bool is_arrow_function = false)
FunctionExpression(SourceRange source_range, const FlyString& name, NonnullRefPtr<Statement> body, Vector<Parameter> parameters, i32 function_length, NonnullRefPtrVector<VariableDeclaration> variables, bool is_generator, bool is_strict_mode, bool is_arrow_function = false)
: Expression(source_range)
, FunctionNode(name, move(body), move(parameters), function_length, move(variables), is_strict_mode)
, FunctionNode(name, move(body), move(parameters), function_length, move(variables), is_generator, is_strict_mode)
, m_is_arrow_function(is_arrow_function)
{
}
@ -318,6 +321,24 @@ public:
Value execute(Interpreter&, GlobalObject&) const override { return {}; }
};
class YieldExpression final : public Expression {
public:
explicit YieldExpression(SourceRange source_range, RefPtr<Expression> argument)
: Expression(move(source_range))
, m_argument(move(argument))
{
}
const Expression* argument() const { return m_argument; }
virtual Value execute(Interpreter&, GlobalObject&) const override;
virtual void dump(int indent) const override;
virtual void generate_bytecode(Bytecode::Generator&) const override;
private:
RefPtr<Expression> m_argument;
};
class ReturnStatement final : public Statement {
public:
explicit ReturnStatement(SourceRange source_range, RefPtr<Expression> argument)

16
Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp
View file

@ -668,9 +668,25 @@ void ReturnStatement::generate_bytecode(Bytecode::Generator& generator) const
{
if (m_argument)
m_argument->generate_bytecode(generator);
if (generator.is_in_generator_function())
generator.emit<Bytecode::Op::Yield>(nullptr);
else
generator.emit<Bytecode::Op::Return>();
}
void YieldExpression::generate_bytecode(Bytecode::Generator& generator) const
{
VERIFY(generator.is_in_generator_function());
if (m_argument)
m_argument->generate_bytecode(generator);
auto& continuation_block = generator.make_block();
generator.emit<Bytecode::Op::Yield>(Bytecode::Label { continuation_block });
generator.switch_to_basic_block(continuation_block);
}
void IfStatement::generate_bytecode(Bytecode::Generator& generator) const
{
// test

19
Userland/Libraries/LibJS/Bytecode/Generator.cpp
View file

@ -23,11 +23,28 @@ Generator::~Generator()
{
}
Executable Generator::generate(ASTNode const& node)
Executable Generator::generate(ASTNode const& node, bool is_in_generator_function)
{
Generator generator;
generator.switch_to_basic_block(generator.make_block());
if (is_in_generator_function) {
generator.enter_generator_context();
// Immediately yield with no value.
auto& start_block = generator.make_block();
generator.emit<Bytecode::Op::Yield>(Label { start_block });
generator.switch_to_basic_block(start_block);
}
node.generate_bytecode(generator);
if (is_in_generator_function) {
// Terminate all unterminated blocks with yield return
for (auto& block : generator.m_root_basic_blocks) {
if (block.is_terminated())
continue;
generator.switch_to_basic_block(block);
generator.emit<Bytecode::Op::LoadImmediate>(js_undefined());
generator.emit<Bytecode::Op::Yield>(nullptr);
}
}
return { move(generator.m_root_basic_blocks), move(generator.m_string_table), generator.m_next_register };
}

7
Userland/Libraries/LibJS/Bytecode/Generator.h
View file

@ -28,7 +28,7 @@ struct Executable {
class Generator {
public:
static Executable generate(ASTNode const&);
static Executable generate(ASTNode const&, bool is_in_generator_function = false);
Register allocate_register();
@ -109,6 +109,10 @@ public:
return m_string_table->insert(string);
}
bool is_in_generator_function() const { return m_is_in_generator_function; }
void enter_generator_context() { m_is_in_generator_function = true; }
void leave_generator_context() { m_is_in_generator_function = false; }
private:
Generator();
~Generator();
@ -122,6 +126,7 @@ private:
u32 m_next_register { 2 };
u32 m_next_block { 1 };
bool m_is_in_generator_function { false };
Vector<Label> m_continuable_scopes;
Vector<Label> m_breakable_scopes;
};

3
Userland/Libraries/LibJS/Bytecode/Instruction.h
View file

@ -61,7 +61,8 @@
O(PushLexicalEnvironment) \
O(EnterUnwindContext) \
O(LeaveUnwindContext) \
O(ContinuePendingUnwind)
O(ContinuePendingUnwind) \
O(Yield)
namespace JS::Bytecode {

9
Userland/Libraries/LibJS/Bytecode/Interpreter.cpp
View file

@ -35,7 +35,7 @@ Interpreter::~Interpreter()
s_current = nullptr;
}
Value Interpreter::run(Executable const& executable)
Value Interpreter::run(Executable const& executable, BasicBlock const* entry_point)
{
dbgln_if(JS_BYTECODE_DEBUG, "Bytecode::Interpreter will run unit {:p}", &executable);
@ -56,10 +56,14 @@ Value Interpreter::run(Executable const& executable)
VERIFY(!vm().exception());
}
auto block = &executable.basic_blocks.first();
auto block = entry_point ?: &executable.basic_blocks.first();
if (m_manually_entered_frames) {
VERIFY(registers().size() >= executable.number_of_registers);
} else {
m_register_windows.append(make<RegisterWindow>());
registers().resize(executable.number_of_registers);
registers()[Register::global_object_index] = Value(&global_object());
}
for (;;) {
Bytecode::InstructionStreamIterator pc(block->instruction_stream());
@ -124,6 +128,7 @@ Value Interpreter::run(Executable const& executable)
vm().set_last_value(Badge<Interpreter> {}, accumulator());
if (!m_manually_entered_frames)
m_register_windows.take_last();
auto return_value = m_return_value.value_or(js_undefined());

16
Userland/Libraries/LibJS/Bytecode/Interpreter.h
View file

@ -30,10 +30,23 @@ public:
GlobalObject& global_object() { return m_global_object; }
VM& vm() { return m_vm; }
Value run(Bytecode::Executable const&);
Value run(Bytecode::Executable const&, Bytecode::BasicBlock const* entry_point = nullptr);
ALWAYS_INLINE Value& accumulator() { return reg(Register::accumulator()); }
Value& reg(Register const& r) { return registers()[r.index()]; }
[[nodiscard]] RegisterWindow snapshot_frame() const { return m_register_windows.last(); }
void enter_frame(RegisterWindow const& frame)
{
++m_manually_entered_frames;
m_register_windows.append(make<RegisterWindow>(frame));
}
void leave_frame()
{
VERIFY(m_manually_entered_frames);
--m_manually_entered_frames;
m_register_windows.take_last();
}
void jump(Label const& label)
{
@ -55,6 +68,7 @@ private:
NonnullOwnPtrVector<RegisterWindow> m_register_windows;
Optional<BasicBlock const*> m_pending_jump;
Value m_return_value;
size_t m_manually_entered_frames { 0 };
Executable const* m_current_executable { nullptr };
Vector<UnwindInfo> m_unwind_contexts;
Handle<Exception> m_saved_exception;

22
Userland/Libraries/LibJS/Bytecode/Op.cpp
View file

@ -218,8 +218,7 @@ void Call::execute(Bytecode::Interpreter& interpreter) const
void NewFunction::execute(Bytecode::Interpreter& interpreter) const
{
auto& vm = interpreter.vm();
auto& global_object = interpreter.global_object();
interpreter.accumulator() = ScriptFunction::create(global_object, m_function_node.name(), m_function_node.body(), m_function_node.parameters(), m_function_node.function_length(), vm.current_scope(), m_function_node.is_strict_mode());
interpreter.accumulator() = ScriptFunction::create(interpreter.global_object(), m_function_node.name(), m_function_node.body(), m_function_node.parameters(), m_function_node.function_length(), vm.current_scope(), m_function_node.is_generator(), m_function_node.is_strict_mode());
}
void Return::execute(Bytecode::Interpreter& interpreter) const
@ -280,6 +279,18 @@ void PushLexicalEnvironment::execute(Bytecode::Interpreter& interpreter) const
interpreter.vm().call_frame().scope = block_lexical_environment;
}
void Yield::execute(Bytecode::Interpreter& interpreter) const
{
auto yielded_value = interpreter.accumulator().value_or(js_undefined());
auto object = JS::Object::create_empty(interpreter.global_object());
object->put("result", yielded_value);
if (m_continuation_label.has_value())
object->put("continuation", Value(static_cast<double>(reinterpret_cast<u64>(&m_continuation_label->block()))));
else
object->put("continuation", Value(0));
interpreter.do_return(object);
}
String Load::to_string(Bytecode::Executable const&) const
{
return String::formatted("Load {}", m_src);
@ -445,4 +456,11 @@ String PushLexicalEnvironment::to_string(const Bytecode::Executable& executable)
return builder.to_string();
}
String Yield::to_string(Bytecode::Executable const&) const
{
if (m_continuation_label.has_value())
return String::formatted("Yield continuation:@{}", m_continuation_label->block().name());
return String::formatted("Yield return");
}
}

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

@ -184,8 +184,6 @@ public:
void execute(Bytecode::Interpreter&) const;
String to_string(Bytecode::Executable const&) const;
size_t length() const { return sizeof(*this) + sizeof(Register) * m_element_count; }
private:
size_t m_element_count { 0 };
Register m_elements[];
@ -462,6 +460,28 @@ private:
Label m_resume_target;
};
class Yield final : public Instruction {
public:
constexpr static bool IsTerminator = true;
explicit Yield(Label continuation_label)
: Instruction(Type::Yield)
, m_continuation_label(continuation_label)
{
}
explicit Yield(std::nullptr_t)
: Instruction(Type::Yield)
{
}
void execute(Bytecode::Interpreter&) const;
String to_string(Bytecode::Executable const&) const;
private:
Optional<Label> m_continuation_label;
};
class PushLexicalEnvironment final : public Instruction {
public:
PushLexicalEnvironment(HashMap<u32, Variable> variables)
@ -472,6 +492,7 @@ public:
void execute(Bytecode::Interpreter&) const;
String to_string(Bytecode::Executable const&) const;
private:
HashMap<u32, Variable> m_variables;
};
}

1
Userland/Libraries/LibJS/CMakeLists.txt
View file

@ -45,6 +45,7 @@ set(SOURCES
Runtime/FunctionConstructor.cpp
Runtime/Function.cpp
Runtime/FunctionPrototype.cpp
Runtime/GeneratorObject.cpp
Runtime/GlobalObject.cpp
Runtime/IndexedProperties.cpp
Runtime/IteratorOperations.cpp

2
Userland/Libraries/LibJS/Interpreter.cpp
View file

@ -79,7 +79,7 @@ void Interpreter::enter_scope(const ScopeNode& scope_node, ScopeType scope_type,
{
ScopeGuard guard([&] {
for (auto& declaration : scope_node.functions()) {
auto* function = ScriptFunction::create(global_object, declaration.name(), declaration.body(), declaration.parameters(), declaration.function_length(), current_scope(), declaration.is_strict_mode());
auto* function = ScriptFunction::create(global_object, declaration.name(), declaration.body(), declaration.parameters(), declaration.function_length(), current_scope(), declaration.is_generator(), declaration.is_strict_mode());
vm().set_variable(declaration.name(), function, global_object);
}
});

29
Userland/Libraries/LibJS/Parser.cpp
View file

@ -590,9 +590,9 @@ NonnullRefPtr<ClassExpression> Parser::parse_class_expression(bool expect_class_
constructor_body->append(create_ast_node<ExpressionStatement>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, move(super_call)));
constructor_body->add_variables(m_parser_state.m_var_scopes.last());
constructor = create_ast_node<FunctionExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, class_name, move(constructor_body), Vector { FunctionNode::Parameter { FlyString { "args" }, nullptr, true } }, 0, NonnullRefPtrVector<VariableDeclaration>(), true);
constructor = create_ast_node<FunctionExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, class_name, move(constructor_body), Vector { FunctionNode::Parameter { FlyString { "args" }, nullptr, true } }, 0, NonnullRefPtrVector<VariableDeclaration>(), false, true);
} else {
constructor = create_ast_node<FunctionExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, class_name, move(constructor_body), Vector<FunctionNode::Parameter> {}, 0, NonnullRefPtrVector<VariableDeclaration>(), true);
constructor = create_ast_node<FunctionExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, class_name, move(constructor_body), Vector<FunctionNode::Parameter> {}, 0, NonnullRefPtrVector<VariableDeclaration>(), false, true);
}
}
@ -634,6 +634,7 @@ NonnullRefPtr<Expression> Parser::parse_primary_expression()
syntax_error("'super' keyword unexpected here");
return create_ast_node<SuperExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() });
case TokenType::Identifier: {
read_as_identifier:;
if (!try_parse_arrow_function_expression_failed_at_position(position())) {
auto arrow_function_result = try_parse_arrow_function_expression(false);
if (!arrow_function_result.is_null())
@ -674,6 +675,10 @@ NonnullRefPtr<Expression> Parser::parse_primary_expression()
}
return parse_new_expression();
}
case TokenType::Yield:
if (!m_parser_state.m_in_generator_function_context)
goto read_as_identifier;
return parse_yield_expression();
default:
expected("primary expression");
consume();
@ -1256,6 +1261,16 @@ NonnullRefPtr<NewExpression> Parser::parse_new_expression()
return create_ast_node<NewExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, move(callee), move(arguments));
}
NonnullRefPtr<YieldExpression> Parser::parse_yield_expression()
{
auto rule_start = push_start();
consume(TokenType::Yield);
RefPtr<Expression> argument;
if (match_expression())
argument = parse_expression(0);
return create_ast_node<YieldExpression>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, move(argument));
}
NonnullRefPtr<ReturnStatement> Parser::parse_return_statement()
{
auto rule_start = push_start();
@ -1336,9 +1351,14 @@ NonnullRefPtr<FunctionNodeType> Parser::parse_function_node(u8 parse_options)
ScopePusher scope(*this, ScopePusher::Var | ScopePusher::Function);
auto is_generator = false;
String name;
if (parse_options & FunctionNodeParseOptions::CheckForFunctionAndName) {
consume(TokenType::Function);
is_generator = match(TokenType::Asterisk);
if (is_generator)
consume(TokenType::Asterisk);
if (FunctionNodeType::must_have_name() || match(TokenType::Identifier))
name = consume(TokenType::Identifier).value();
}
@ -1351,6 +1371,7 @@ NonnullRefPtr<FunctionNodeType> Parser::parse_function_node(u8 parse_options)
function_length = parameters.size();
TemporaryChange change(m_parser_state.m_in_function_context, true);
TemporaryChange generator_change(m_parser_state.m_in_generator_function_context, m_parser_state.m_in_generator_function_context || is_generator);
auto old_labels_in_scope = move(m_parser_state.m_labels_in_scope);
ScopeGuard guard([&]() {
m_parser_state.m_labels_in_scope = move(old_labels_in_scope);
@ -1360,7 +1381,7 @@ NonnullRefPtr<FunctionNodeType> Parser::parse_function_node(u8 parse_options)
auto body = parse_block_statement(is_strict);
body->add_variables(m_parser_state.m_var_scopes.last());
body->add_functions(m_parser_state.m_function_scopes.last());
return create_ast_node<FunctionNodeType>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, name, move(body), move(parameters), function_length, NonnullRefPtrVector<VariableDeclaration>(), is_strict);
return create_ast_node<FunctionNodeType>({ m_parser_state.m_current_token.filename(), rule_start.position(), position() }, name, move(body), move(parameters), function_length, NonnullRefPtrVector<VariableDeclaration>(), is_generator, is_strict);
}
Vector<FunctionNode::Parameter> Parser::parse_formal_parameters(int& function_length, u8 parse_options)
@ -2009,6 +2030,7 @@ bool Parser::match_expression() const
|| type == TokenType::This
|| type == TokenType::Super
|| type == TokenType::RegexLiteral
|| type == TokenType::Yield
|| match_unary_prefixed_expression();
}
@ -2085,6 +2107,7 @@ bool Parser::match_statement() const
auto type = m_parser_state.m_current_token.type();
return match_expression()
|| type == TokenType::Return
|| type == TokenType::Yield
|| type == TokenType::Do
|| type == TokenType::If
|| type == TokenType::Throw

2
Userland/Libraries/LibJS/Parser.h
View file

@ -77,6 +77,7 @@ public:
NonnullRefPtr<NewExpression> parse_new_expression();
NonnullRefPtr<ClassDeclaration> parse_class_declaration();
NonnullRefPtr<ClassExpression> parse_class_expression(bool expect_class_name);
NonnullRefPtr<YieldExpression> parse_yield_expression();
NonnullRefPtr<Expression> parse_property_key();
NonnullRefPtr<AssignmentExpression> parse_assignment_expression(AssignmentOp, NonnullRefPtr<Expression> lhs, int min_precedence, Associativity);
@ -200,6 +201,7 @@ private:
bool m_allow_super_property_lookup { false };
bool m_allow_super_constructor_call { false };
bool m_in_function_context { false };
bool m_in_generator_function_context { false };
bool m_in_arrow_function_context { false };
bool m_in_break_context { false };
bool m_in_continue_context { false };

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

@ -293,6 +293,8 @@ struct CommonPropertyNames {
FlyString catch_ { "catch" };
FlyString delete_ { "delete" };
FlyString for_ { "for" };
FlyString return_ { "return" };
FlyString throw_ { "throw" };
#define __ENUMERATE(x) FlyString x { #x };
ENUMERATE_STANDARD_PROPERTY_NAMES(__ENUMERATE)
#undef __ENUMERATE

163
Userland/Libraries/LibJS/Runtime/GeneratorObject.cpp Normal file
View file

@ -0,0 +1,163 @@
/*
* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/TemporaryChange.h>
#include <LibJS/Bytecode/Generator.h>
#include <LibJS/Bytecode/Interpreter.h>
#include <LibJS/Runtime/GeneratorObject.h>
#include <LibJS/Runtime/GlobalObject.h>
namespace JS {
GeneratorObject* GeneratorObject::create(GlobalObject& global_object, Value initial_value, ScriptFunction* generating_function, ScopeObject* generating_scope, Bytecode::RegisterWindow frame)
{
auto object = global_object.heap().allocate<GeneratorObject>(global_object, global_object);
object->m_generating_function = generating_function;
object->m_scope = generating_scope;
object->m_frame = move(frame);
object->m_previous_value = initial_value;
return object;
}
GeneratorObject::GeneratorObject(GlobalObject& global_object)
: Object(*global_object.object_prototype())
{
}
void GeneratorObject::initialize(GlobalObject& global_object)
{
auto& vm = this->vm();
Object::initialize(global_object);
define_native_function(vm.names.next, next);
define_native_function(vm.names.return_, return_);
define_native_function(vm.names.throw_, throw_);
}
GeneratorObject::~GeneratorObject()
{
}
void GeneratorObject::visit_edges(Cell::Visitor& visitor)
{
Object::visit_edges(visitor);
visitor.visit(m_scope);
visitor.visit(m_generating_function);
if (m_previous_value.is_object())
visitor.visit(&m_previous_value.as_object());
}
GeneratorObject* GeneratorObject::typed_this(VM& vm, GlobalObject& global_object)
{
auto* this_object = vm.this_value(global_object).to_object(global_object);
if (!this_object)
return {};
if (!is<GeneratorObject>(this_object)) {
vm.throw_exception<TypeError>(global_object, ErrorType::NotA, "Generator");
return nullptr;
}
return static_cast<GeneratorObject*>(this_object);
}
Value GeneratorObject::next_impl(VM& vm, GlobalObject& global_object, Optional<Value> value_to_throw)
{
auto bytecode_interpreter = Bytecode::Interpreter::current();
VERIFY(bytecode_interpreter);
auto generated_value = [](Value value) {
if (value.is_object())
return value.as_object().get("result");
return value.is_empty() ? js_undefined() : value;
};
auto generated_continuation = [&](Value value) -> Bytecode::BasicBlock const* {
if (value.is_object())
return reinterpret_cast<Bytecode::BasicBlock const*>(static_cast<u64>(value.as_object().get("continuation").to_double(global_object)));
return nullptr;
};
Value previous_generated_value { generated_value(m_previous_value) };
if (vm.exception())
return {};
auto result = Object::create_empty(global_object);
result->put("value", previous_generated_value);
if (m_done) {
result->put("done", Value(true));
return result;
}
// Extract the continuation
auto next_block = generated_continuation(m_previous_value);
if (vm.exception())
return {};
if (!next_block) {
// The generator has terminated, now we can simply return done=true.
m_done = true;
result->put("done", Value(true));
return result;
}
// Make sure it's an actual block
VERIFY(!m_generating_function->bytecode_executable()->basic_blocks.find_if([next_block](auto& block) { return block == next_block; }).is_end());
// Restore the snapshot registers
bytecode_interpreter->enter_frame(m_frame);
// Pretend that 'yield' returned the passed value, or threw
if (value_to_throw.has_value()) {
vm.throw_exception(global_object, value_to_throw.release_value());
bytecode_interpreter->accumulator() = js_undefined();
} else {
bytecode_interpreter->accumulator() = vm.argument(0);
}
// Temporarily switch to the captured scope
TemporaryChange change { vm.call_frame().scope, m_scope };
m_previous_value = bytecode_interpreter->run(*m_generating_function->bytecode_executable(), next_block);
bytecode_interpreter->leave_frame();
m_done = generated_continuation(m_previous_value) == nullptr;
result->put("value", generated_value(m_previous_value));
result->put("done", Value(m_done));
if (vm.exception())
return {};
return result;
}
JS_DEFINE_NATIVE_FUNCTION(GeneratorObject::next)
{
auto object = typed_this(vm, global_object);
if (!object)
return {};
return object->next_impl(vm, global_object, {});
}
JS_DEFINE_NATIVE_FUNCTION(GeneratorObject::return_)
{
auto object = typed_this(vm, global_object);
if (!object)
return {};
object->m_done = true;
return object->next_impl(vm, global_object, {});
}
JS_DEFINE_NATIVE_FUNCTION(GeneratorObject::throw_)
{
auto object = typed_this(vm, global_object);
if (!object)
return {};
return object->next_impl(vm, global_object, vm.argument(0));
}
}

40
Userland/Libraries/LibJS/Runtime/GeneratorObject.h Normal file
View file

@ -0,0 +1,40 @@
/*
* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibJS/Runtime/Object.h>
#include <LibJS/Runtime/ScriptFunction.h>
namespace JS {
class GeneratorObject final : public Object {
JS_OBJECT(GeneratorObject, Object);
public:
static GeneratorObject* create(GlobalObject&, Value, ScriptFunction*, ScopeObject*, Bytecode::RegisterWindow);
explicit GeneratorObject(GlobalObject&);
virtual void initialize(GlobalObject&) override;
virtual ~GeneratorObject() override;
void visit_edges(Cell::Visitor&) override;
static GeneratorObject* typed_this(VM&, GlobalObject&);
private:
JS_DECLARE_NATIVE_FUNCTION(next);
JS_DECLARE_NATIVE_FUNCTION(return_);
JS_DECLARE_NATIVE_FUNCTION(throw_);
Value next_impl(VM&, GlobalObject&, Optional<Value> value_to_throw);
ScopeObject* m_scope { nullptr };
ScriptFunction* m_generating_function { nullptr };
Value m_previous_value;
Bytecode::RegisterWindow m_frame;
bool m_done { false };
};
}

18
Userland/Libraries/LibJS/Runtime/ScriptFunction.cpp
View file

@ -13,7 +13,9 @@
#include <LibJS/Interpreter.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/GeneratorObject.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/NativeFunction.h>
#include <LibJS/Runtime/ScriptFunction.h>
#include <LibJS/Runtime/Value.h>
@ -31,18 +33,19 @@ static ScriptFunction* typed_this(VM& vm, GlobalObject& global_object)
return static_cast<ScriptFunction*>(this_object);
}
ScriptFunction* ScriptFunction::create(GlobalObject& global_object, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, bool is_strict, bool is_arrow_function)
ScriptFunction* ScriptFunction::create(GlobalObject& global_object, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, bool is_generator, bool is_strict, bool is_arrow_function)
{
return global_object.heap().allocate<ScriptFunction>(global_object, global_object, name, body, move(parameters), m_function_length, parent_scope, *global_object.function_prototype(), is_strict, is_arrow_function);
return global_object.heap().allocate<ScriptFunction>(global_object, global_object, name, body, move(parameters), m_function_length, parent_scope, *global_object.function_prototype(), is_generator, is_strict, is_arrow_function);
}
ScriptFunction::ScriptFunction(GlobalObject& global_object, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, Object& prototype, bool is_strict, bool is_arrow_function)
ScriptFunction::ScriptFunction(GlobalObject& global_object, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, Object& prototype, bool is_generator, bool is_strict, bool is_arrow_function)
: Function(prototype, is_arrow_function ? vm().this_value(global_object) : Value(), {})
, m_name(name)
, m_body(body)
, m_parameters(move(parameters))
, m_parent_scope(parent_scope)
, m_function_length(m_function_length)
, m_is_generator(is_generator)
, m_is_strict(is_strict)
, m_is_arrow_function(is_arrow_function)
{
@ -152,15 +155,20 @@ Value ScriptFunction::execute_function_body()
if (bytecode_interpreter) {
prepare_arguments();
if (!m_bytecode_executable.has_value()) {
m_bytecode_executable = Bytecode::Generator::generate(m_body);
m_bytecode_executable = Bytecode::Generator::generate(m_body, m_is_generator);
if constexpr (JS_BYTECODE_DEBUG) {
dbgln("Compiled Bytecode::Block for function '{}':", m_name);
for (auto& block : m_bytecode_executable->basic_blocks)
block.dump(*m_bytecode_executable);
}
}
return bytecode_interpreter->run(*m_bytecode_executable);
auto result = bytecode_interpreter->run(*m_bytecode_executable);
if (!m_is_generator)
return result;
return GeneratorObject::create(global_object(), result, this, vm.call_frame().scope, bytecode_interpreter->snapshot_frame());
} else {
VERIFY(!m_is_generator);
OwnPtr<Interpreter> local_interpreter;
ast_interpreter = vm.interpreter_if_exists();

7
Userland/Libraries/LibJS/Runtime/ScriptFunction.h
View file

@ -16,9 +16,9 @@ class ScriptFunction final : public Function {
JS_OBJECT(ScriptFunction, Function);
public:
static ScriptFunction* create(GlobalObject&, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, bool is_strict, bool is_arrow_function = false);
static ScriptFunction* create(GlobalObject&, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, bool is_generator, bool is_strict, bool is_arrow_function = false);
ScriptFunction(GlobalObject&, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, Object& prototype, bool is_strict, bool is_arrow_function = false);
ScriptFunction(GlobalObject&, const FlyString& name, const Statement& body, Vector<FunctionNode::Parameter> parameters, i32 m_function_length, ScopeObject* parent_scope, Object& prototype, bool is_generator, bool is_strict, bool is_arrow_function = false);
virtual void initialize(GlobalObject&) override;
virtual ~ScriptFunction();
@ -33,6 +33,8 @@ public:
void set_is_class_constructor() { m_is_class_constructor = true; };
auto& bytecode_executable() const { return m_bytecode_executable; }
protected:
virtual bool is_strict_mode() const final { return m_is_strict; }
@ -51,6 +53,7 @@ private:
Optional<Bytecode::Executable> m_bytecode_executable;
ScopeObject* m_parent_scope { nullptr };
i32 m_function_length { 0 };
bool m_is_generator { false };
bool m_is_strict { false };
bool m_is_arrow_function { false };
bool m_is_class_constructor { false };

2
Userland/Libraries/LibWeb/HTML/GlobalEventHandlers.cpp
View file

@ -49,7 +49,7 @@ void GlobalEventHandlers::set_event_handler_attribute(const FlyString& name, HTM
dbgln("Failed to parse script in event handler attribute '{}'", name);
return;
}
auto* function = JS::ScriptFunction::create(self.script_execution_context()->interpreter().global_object(), name, program->body(), program->parameters(), program->function_length(), nullptr, false, false);
auto* function = JS::ScriptFunction::create(self.script_execution_context()->interpreter().global_object(), name, program->body(), program->parameters(), program->function_length(), nullptr, false, false, false);
VERIFY(function);
listener = adopt_ref(*new DOM::EventListener(JS::make_handle(static_cast<JS::Function*>(function))));
}

2
Userland/Libraries/LibWeb/HTML/WebSocket.cpp
View file

@ -246,7 +246,7 @@ void WebSocket::set_event_handler_attribute(const FlyString& name, HTML::EventHa
dbgln("Failed to parse script in event handler attribute '{}'", name);
return;
}
auto* function = JS::ScriptFunction::create(script_execution_context()->interpreter().global_object(), name, program->body(), program->parameters(), program->function_length(), nullptr, false, false);
auto* function = JS::ScriptFunction::create(script_execution_context()->interpreter().global_object(), name, program->body(), program->parameters(), program->function_length(), nullptr, false, false, false);
VERIFY(function);
listener = adopt_ref(*new DOM::EventListener(JS::make_handle(static_cast<JS::Function*>(function))));
}