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chromium / v8 / v8 / 78bb3c6ef99fb9149923056b1b25d2a8859e10b7 / . / src / parsing / parser.cc
blob: 6f92bb7c7ad2875e882717fa69777a1e43fb5b19 [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/parsing/parser.h"
#include "src/api.h"
#include "src/ast/ast.h"
#include "src/ast/ast-expression-rewriter.h"
#include "src/ast/ast-expression-visitor.h"
#include "src/ast/ast-literal-reindexer.h"
#include "src/ast/scopeinfo.h"
#include "src/bailout-reason.h"
#include "src/base/platform/platform.h"
#include "src/bootstrapper.h"
#include "src/char-predicates-inl.h"
#include "src/codegen.h"
#include "src/compiler.h"
#include "src/messages.h"
#include "src/parsing/parameter-initializer-rewriter.h"
#include "src/parsing/parser-base.h"
#include "src/parsing/rewriter.h"
#include "src/parsing/scanner-character-streams.h"
#include "src/runtime/runtime.h"
#include "src/string-stream.h"
#include "src/tracing/trace-event.h"
namespace v8 {
namespace internal {
ScriptData::ScriptData(const byte* data, int length)
: owns_data_(false), rejected_(false), data_(data), length_(length) {
if (!IsAligned(reinterpret_cast<intptr_t>(data), kPointerAlignment)) {
byte* copy = NewArray<byte>(length);
DCHECK(IsAligned(reinterpret_cast<intptr_t>(copy), kPointerAlignment));
CopyBytes(copy, data, length);
data_ = copy;
AcquireDataOwnership();
}
}
ParseInfo::ParseInfo(Zone* zone)
: zone_(zone),
flags_(0),
source_stream_(nullptr),
source_stream_encoding_(ScriptCompiler::StreamedSource::ONE_BYTE),
extension_(nullptr),
compile_options_(ScriptCompiler::kNoCompileOptions),
script_scope_(nullptr),
unicode_cache_(nullptr),
stack_limit_(0),
hash_seed_(0),
isolate_(nullptr),
cached_data_(nullptr),
ast_value_factory_(nullptr),
literal_(nullptr),
scope_(nullptr) {}
ParseInfo::ParseInfo(Zone* zone, Handle<JSFunction> function)
: ParseInfo(zone, Handle<SharedFunctionInfo>(function->shared())) {
set_context(Handle<Context>(function->context()));
}
ParseInfo::ParseInfo(Zone* zone, Handle<SharedFunctionInfo> shared)
: ParseInfo(zone) {
isolate_ = shared->GetIsolate();
set_lazy();
set_hash_seed(isolate_->heap()->HashSeed());
set_stack_limit(isolate_->stack_guard()->real_climit());
set_unicode_cache(isolate_->unicode_cache());
set_language_mode(shared->language_mode());
set_shared_info(shared);
Handle<Script> script(Script::cast(shared->script()));
set_script(script);
if (!script.is_null() && script->type() == Script::TYPE_NATIVE) {
set_native();
}
}
ParseInfo::ParseInfo(Zone* zone, Handle<Script> script) : ParseInfo(zone) {
isolate_ = script->GetIsolate();
set_hash_seed(isolate_->heap()->HashSeed());
set_stack_limit(isolate_->stack_guard()->real_climit());
set_unicode_cache(isolate_->unicode_cache());
set_script(script);
if (script->type() == Script::TYPE_NATIVE) {
set_native();
}
}
FunctionEntry ParseData::GetFunctionEntry(int start) {
// The current pre-data entry must be a FunctionEntry with the given
// start position.
if ((function_index_ + FunctionEntry::kSize <= Length()) &&
(static_cast<int>(Data()[function_index_]) == start)) {
int index = function_index_;
function_index_ += FunctionEntry::kSize;
Vector<unsigned> subvector(&(Data()[index]), FunctionEntry::kSize);
return FunctionEntry(subvector);
}
return FunctionEntry();
}
int ParseData::FunctionCount() {
int functions_size = FunctionsSize();
if (functions_size < 0) return 0;
if (functions_size % FunctionEntry::kSize != 0) return 0;
return functions_size / FunctionEntry::kSize;
}
bool ParseData::IsSane() {
if (!IsAligned(script_data_->length(), sizeof(unsigned))) return false;
// Check that the header data is valid and doesn't specify
// point to positions outside the store.
int data_length = Length();
if (data_length < PreparseDataConstants::kHeaderSize) return false;
if (Magic() != PreparseDataConstants::kMagicNumber) return false;
if (Version() != PreparseDataConstants::kCurrentVersion) return false;
if (HasError()) return false;
// Check that the space allocated for function entries is sane.
int functions_size = FunctionsSize();
if (functions_size < 0) return false;
if (functions_size % FunctionEntry::kSize != 0) return false;
// Check that the total size has room for header and function entries.
int minimum_size =
PreparseDataConstants::kHeaderSize + functions_size;
if (data_length < minimum_size) return false;
return true;
}
void ParseData::Initialize() {
// Prepares state for use.
int data_length = Length();
if (data_length >= PreparseDataConstants::kHeaderSize) {
function_index_ = PreparseDataConstants::kHeaderSize;
}
}
bool ParseData::HasError() {
return Data()[PreparseDataConstants::kHasErrorOffset];
}
unsigned ParseData::Magic() {
return Data()[PreparseDataConstants::kMagicOffset];
}
unsigned ParseData::Version() {
return Data()[PreparseDataConstants::kVersionOffset];
}
int ParseData::FunctionsSize() {
return static_cast<int>(Data()[PreparseDataConstants::kFunctionsSizeOffset]);
}
void Parser::SetCachedData(ParseInfo* info) {
if (compile_options_ == ScriptCompiler::kNoCompileOptions) {
cached_parse_data_ = NULL;
} else {
DCHECK(info->cached_data() != NULL);
if (compile_options_ == ScriptCompiler::kConsumeParserCache) {
cached_parse_data_ = ParseData::FromCachedData(*info->cached_data());
}
}
}
FunctionLiteral* Parser::DefaultConstructor(const AstRawString* name,
bool call_super, Scope* scope,
int pos, int end_pos,
LanguageMode language_mode) {
int materialized_literal_count = -1;
int expected_property_count = -1;
int parameter_count = 0;
if (name == nullptr) name = ast_value_factory()->empty_string();
FunctionKind kind = call_super ? FunctionKind::kDefaultSubclassConstructor
: FunctionKind::kDefaultBaseConstructor;
Scope* function_scope = NewScope(scope, FUNCTION_SCOPE, kind);
SetLanguageMode(function_scope,
static_cast<LanguageMode>(language_mode | STRICT));
// Set start and end position to the same value
function_scope->set_start_position(pos);
function_scope->set_end_position(pos);
ZoneList<Statement*>* body = NULL;
{
AstNodeFactory function_factory(ast_value_factory());
FunctionState function_state(&function_state_, &scope_, function_scope,
kind, &function_factory);
body = new (zone()) ZoneList<Statement*>(call_super ? 2 : 1, zone());
if (call_super) {
// $super_constructor = %_GetSuperConstructor(<this-function>)
// %reflect_construct(
// $super_constructor, InternalArray(...args), new.target)
auto constructor_args_name = ast_value_factory()->empty_string();
bool is_duplicate;
bool is_rest = true;
bool is_optional = false;
Variable* constructor_args =
function_scope->DeclareParameter(constructor_args_name, TEMPORARY,
is_optional, is_rest, &is_duplicate);
ZoneList<Expression*>* args =
new (zone()) ZoneList<Expression*>(2, zone());
VariableProxy* this_function_proxy = scope_->NewUnresolved(
factory(), ast_value_factory()->this_function_string(),
Variable::NORMAL, pos);
ZoneList<Expression*>* tmp =
new (zone()) ZoneList<Expression*>(1, zone());
tmp->Add(this_function_proxy, zone());
Expression* super_constructor = factory()->NewCallRuntime(
Runtime::kInlineGetSuperConstructor, tmp, pos);
args->Add(super_constructor, zone());
Spread* spread_args = factory()->NewSpread(
factory()->NewVariableProxy(constructor_args), pos, pos);
ZoneList<Expression*>* spread_args_expr =
new (zone()) ZoneList<Expression*>(1, zone());
spread_args_expr->Add(spread_args, zone());
args->AddAll(*PrepareSpreadArguments(spread_args_expr), zone());
VariableProxy* new_target_proxy = scope_->NewUnresolved(
factory(), ast_value_factory()->new_target_string(), Variable::NORMAL,
pos);
args->Add(new_target_proxy, zone());
CallRuntime* call = factory()->NewCallRuntime(
Context::REFLECT_CONSTRUCT_INDEX, args, pos);
body->Add(factory()->NewReturnStatement(call, pos), zone());
}
materialized_literal_count = function_state.materialized_literal_count();
expected_property_count = function_state.expected_property_count();
}
FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
name, function_scope, body, materialized_literal_count,
expected_property_count, parameter_count,
FunctionLiteral::kNoDuplicateParameters,
FunctionLiteral::kAnonymousExpression,
FunctionLiteral::kShouldLazyCompile, kind, pos);
return function_literal;
}
// ----------------------------------------------------------------------------
// Target is a support class to facilitate manipulation of the
// Parser's target_stack_ (the stack of potential 'break' and
// 'continue' statement targets). Upon construction, a new target is
// added; it is removed upon destruction.
class Target BASE_EMBEDDED {
public:
Target(Target** variable, BreakableStatement* statement)
: variable_(variable), statement_(statement), previous_(*variable) {
*variable = this;
}
~Target() {
*variable_ = previous_;
}
Target* previous() { return previous_; }
BreakableStatement* statement() { return statement_; }
private:
Target** variable_;
BreakableStatement* statement_;
Target* previous_;
};
class TargetScope BASE_EMBEDDED {
public:
explicit TargetScope(Target** variable)
: variable_(variable), previous_(*variable) {
*variable = NULL;
}
~TargetScope() {
*variable_ = previous_;
}
private:
Target** variable_;
Target* previous_;
};
// ----------------------------------------------------------------------------
// The CHECK_OK macro is a convenient macro to enforce error
// handling for functions that may fail (by returning !*ok).
//
// CAUTION: This macro appends extra statements after a call,
// thus it must never be used where only a single statement
// is correct (e.g. an if statement branch w/o braces)!
#define CHECK_OK ok); \
if (!*ok) return NULL; \
((void)0
#define DUMMY ) // to make indentation work
#undef DUMMY
#define CHECK_FAILED /**/); \
if (failed_) return NULL; \
((void)0
#define DUMMY ) // to make indentation work
#undef DUMMY
// ----------------------------------------------------------------------------
// Implementation of Parser
bool ParserTraits::IsEval(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->eval_string();
}
bool ParserTraits::IsArguments(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->arguments_string();
}
bool ParserTraits::IsEvalOrArguments(const AstRawString* identifier) const {
return IsEval(identifier) || IsArguments(identifier);
}
bool ParserTraits::IsUndefined(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->undefined_string();
}
bool ParserTraits::IsAwait(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->await_string();
}
bool ParserTraits::IsPrototype(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->prototype_string();
}
bool ParserTraits::IsConstructor(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->constructor_string();
}
bool ParserTraits::IsThisProperty(Expression* expression) {
DCHECK(expression != NULL);
Property* property = expression->AsProperty();
return property != NULL && property->obj()->IsVariableProxy() &&
property->obj()->AsVariableProxy()->is_this();
}
bool ParserTraits::IsIdentifier(Expression* expression) {
VariableProxy* operand = expression->AsVariableProxy();
return operand != NULL && !operand->is_this();
}
void ParserTraits::PushPropertyName(FuncNameInferrer* fni,
Expression* expression) {
if (expression->IsPropertyName()) {
fni->PushLiteralName(expression->AsLiteral()->AsRawPropertyName());
} else {
fni->PushLiteralName(
parser_->ast_value_factory()->anonymous_function_string());
}
}
void ParserTraits::CheckAssigningFunctionLiteralToProperty(Expression* left,
Expression* right) {
DCHECK(left != NULL);
if (left->IsProperty() && right->IsFunctionLiteral()) {
right->AsFunctionLiteral()->set_pretenure();
}
}
Expression* ParserTraits::MarkExpressionAsAssigned(Expression* expression) {
VariableProxy* proxy =
expression != NULL ? expression->AsVariableProxy() : NULL;
if (proxy != NULL) proxy->set_is_assigned();
return expression;
}
bool ParserTraits::ShortcutNumericLiteralBinaryExpression(
Expression** x, Expression* y, Token::Value op, int pos,
AstNodeFactory* factory) {
if ((*x)->AsLiteral() && (*x)->AsLiteral()->raw_value()->IsNumber() &&
y->AsLiteral() && y->AsLiteral()->raw_value()->IsNumber()) {
double x_val = (*x)->AsLiteral()->raw_value()->AsNumber();
double y_val = y->AsLiteral()->raw_value()->AsNumber();
bool x_has_dot = (*x)->AsLiteral()->raw_value()->ContainsDot();
bool y_has_dot = y->AsLiteral()->raw_value()->ContainsDot();
bool has_dot = x_has_dot || y_has_dot;
switch (op) {
case Token::ADD:
*x = factory->NewNumberLiteral(x_val + y_val, pos, has_dot);
return true;
case Token::SUB:
*x = factory->NewNumberLiteral(x_val - y_val, pos, has_dot);
return true;
case Token::MUL:
*x = factory->NewNumberLiteral(x_val * y_val, pos, has_dot);
return true;
case Token::DIV:
*x = factory->NewNumberLiteral(x_val / y_val, pos, has_dot);
return true;
case Token::BIT_OR: {
int value = DoubleToInt32(x_val) | DoubleToInt32(y_val);
*x = factory->NewNumberLiteral(value, pos, has_dot);
return true;
}
case Token::BIT_AND: {
int value = DoubleToInt32(x_val) & DoubleToInt32(y_val);
*x = factory->NewNumberLiteral(value, pos, has_dot);
return true;
}
case Token::BIT_XOR: {
int value = DoubleToInt32(x_val) ^ DoubleToInt32(y_val);
*x = factory->NewNumberLiteral(value, pos, has_dot);
return true;
}
case Token::SHL: {
int value = DoubleToInt32(x_val) << (DoubleToInt32(y_val) & 0x1f);
*x = factory->NewNumberLiteral(value, pos, has_dot);
return true;
}
case Token::SHR: {
uint32_t shift = DoubleToInt32(y_val) & 0x1f;
uint32_t value = DoubleToUint32(x_val) >> shift;
*x = factory->NewNumberLiteral(value, pos, has_dot);
return true;
}
case Token::SAR: {
uint32_t shift = DoubleToInt32(y_val) & 0x1f;
int value = ArithmeticShiftRight(DoubleToInt32(x_val), shift);
*x = factory->NewNumberLiteral(value, pos, has_dot);
return true;
}
case Token::EXP: {
double value = Pow(x_val, y_val);
int int_value = static_cast<int>(value);
*x = factory->NewNumberLiteral(
int_value == value && value != -0.0 ? int_value : value, pos,
has_dot);
return true;
}
default:
break;
}
}
return false;
}
Expression* ParserTraits::BuildUnaryExpression(Expression* expression,
Token::Value op, int pos,
AstNodeFactory* factory) {
DCHECK(expression != NULL);
if (expression->IsLiteral()) {
const AstValue* literal = expression->AsLiteral()->raw_value();
if (op == Token::NOT) {
// Convert the literal to a boolean condition and negate it.
bool condition = literal->BooleanValue();
return factory->NewBooleanLiteral(!condition, pos);
} else if (literal->IsNumber()) {
// Compute some expressions involving only number literals.
double value = literal->AsNumber();
bool has_dot = literal->ContainsDot();
switch (op) {
case Token::ADD:
return expression;
case Token::SUB:
return factory->NewNumberLiteral(-value, pos, has_dot);
case Token::BIT_NOT:
return factory->NewNumberLiteral(~DoubleToInt32(value), pos, has_dot);
default:
break;
}
}
}
// Desugar '+foo' => 'foo*1'
if (op == Token::ADD) {
return factory->NewBinaryOperation(
Token::MUL, expression, factory->NewNumberLiteral(1, pos, true), pos);
}
// The same idea for '-foo' => 'foo*(-1)'.
if (op == Token::SUB) {
return factory->NewBinaryOperation(
Token::MUL, expression, factory->NewNumberLiteral(-1, pos), pos);
}
// ...and one more time for '~foo' => 'foo^(~0)'.
if (op == Token::BIT_NOT) {
return factory->NewBinaryOperation(
Token::BIT_XOR, expression, factory->NewNumberLiteral(~0, pos), pos);
}
return factory->NewUnaryOperation(op, expression, pos);
}
Expression* ParserTraits::BuildIteratorResult(Expression* value, bool done) {
int pos = RelocInfo::kNoPosition;
AstNodeFactory* factory = parser_->factory();
Zone* zone = parser_->zone();
if (value == nullptr) value = factory->NewUndefinedLiteral(pos);
auto args = new (zone) ZoneList<Expression*>(2, zone);
args->Add(value, zone);
args->Add(factory->NewBooleanLiteral(done, pos), zone);
return factory->NewCallRuntime(Runtime::kInlineCreateIterResultObject, args,
pos);
}
Expression* ParserTraits::NewThrowReferenceError(
MessageTemplate::Template message, int pos) {
return NewThrowError(Runtime::kNewReferenceError, message,
parser_->ast_value_factory()->empty_string(), pos);
}
Expression* ParserTraits::NewThrowSyntaxError(MessageTemplate::Template message,
const AstRawString* arg,
int pos) {
return NewThrowError(Runtime::kNewSyntaxError, message, arg, pos);
}
Expression* ParserTraits::NewThrowTypeError(MessageTemplate::Template message,
const AstRawString* arg, int pos) {
return NewThrowError(Runtime::kNewTypeError, message, arg, pos);
}
Expression* ParserTraits::NewThrowError(Runtime::FunctionId id,
MessageTemplate::Template message,
const AstRawString* arg, int pos) {
Zone* zone = parser_->zone();
ZoneList<Expression*>* args = new (zone) ZoneList<Expression*>(2, zone);
args->Add(parser_->factory()->NewSmiLiteral(message, pos), zone);
args->Add(parser_->factory()->NewStringLiteral(arg, pos), zone);
CallRuntime* call_constructor =
parser_->factory()->NewCallRuntime(id, args, pos);
return parser_->factory()->NewThrow(call_constructor, pos);
}
void ParserTraits::ReportMessageAt(Scanner::Location source_location,
MessageTemplate::Template message,
const char* arg, ParseErrorType error_type) {
if (parser_->stack_overflow()) {
// Suppress the error message (syntax error or such) in the presence of a
// stack overflow. The isolate allows only one pending exception at at time
// and we want to report the stack overflow later.
return;
}
parser_->pending_error_handler_.ReportMessageAt(source_location.beg_pos,
source_location.end_pos,
message, arg, error_type);
}
void ParserTraits::ReportMessage(MessageTemplate::Template message,
const char* arg, ParseErrorType error_type) {
Scanner::Location source_location = parser_->scanner()->location();
ReportMessageAt(source_location, message, arg, error_type);
}
void ParserTraits::ReportMessage(MessageTemplate::Template message,
const AstRawString* arg,
ParseErrorType error_type) {
Scanner::Location source_location = parser_->scanner()->location();
ReportMessageAt(source_location, message, arg, error_type);
}
void ParserTraits::ReportMessageAt(Scanner::Location source_location,
MessageTemplate::Template message,
const AstRawString* arg,
ParseErrorType error_type) {
if (parser_->stack_overflow()) {
// Suppress the error message (syntax error or such) in the presence of a
// stack overflow. The isolate allows only one pending exception at at time
// and we want to report the stack overflow later.
return;
}
parser_->pending_error_handler_.ReportMessageAt(source_location.beg_pos,
source_location.end_pos,
message, arg, error_type);
}
const AstRawString* ParserTraits::GetSymbol(Scanner* scanner) {
const AstRawString* result =
parser_->scanner()->CurrentSymbol(parser_->ast_value_factory());
DCHECK(result != NULL);
return result;
}
const AstRawString* ParserTraits::GetNumberAsSymbol(Scanner* scanner) {
double double_value = parser_->scanner()->DoubleValue();
char array[100];
const char* string = DoubleToCString(double_value, ArrayVector(array));
return parser_->ast_value_factory()->GetOneByteString(string);
}
const AstRawString* ParserTraits::GetNextSymbol(Scanner* scanner) {
return parser_->scanner()->NextSymbol(parser_->ast_value_factory());
}
Expression* ParserTraits::ThisExpression(Scope* scope, AstNodeFactory* factory,
int pos) {
return scope->NewUnresolved(factory,
parser_->ast_value_factory()->this_string(),
Variable::THIS, pos, pos + 4);
}
Expression* ParserTraits::SuperPropertyReference(Scope* scope,
AstNodeFactory* factory,
int pos) {
// this_function[home_object_symbol]
VariableProxy* this_function_proxy = scope->NewUnresolved(
factory, parser_->ast_value_factory()->this_function_string(),
Variable::NORMAL, pos);
Expression* home_object_symbol_literal =
factory->NewSymbolLiteral("home_object_symbol", RelocInfo::kNoPosition);
Expression* home_object = factory->NewProperty(
this_function_proxy, home_object_symbol_literal, pos);
return factory->NewSuperPropertyReference(
ThisExpression(scope, factory, pos)->AsVariableProxy(), home_object, pos);
}
Expression* ParserTraits::SuperCallReference(Scope* scope,
AstNodeFactory* factory, int pos) {
VariableProxy* new_target_proxy = scope->NewUnresolved(
factory, parser_->ast_value_factory()->new_target_string(),
Variable::NORMAL, pos);
VariableProxy* this_function_proxy = scope->NewUnresolved(
factory, parser_->ast_value_factory()->this_function_string(),
Variable::NORMAL, pos);
return factory->NewSuperCallReference(
ThisExpression(scope, factory, pos)->AsVariableProxy(), new_target_proxy,
this_function_proxy, pos);
}
Expression* ParserTraits::NewTargetExpression(Scope* scope,
AstNodeFactory* factory,
int pos) {
static const int kNewTargetStringLength = 10;
auto proxy = scope->NewUnresolved(
factory, parser_->ast_value_factory()->new_target_string(),
Variable::NORMAL, pos, pos + kNewTargetStringLength);
proxy->set_is_new_target();
return proxy;
}
Expression* ParserTraits::FunctionSentExpression(Scope* scope,
AstNodeFactory* factory,
int pos) {
// We desugar function.sent into %_GeneratorGetInput(generator).
Zone* zone = parser_->zone();
ZoneList<Expression*>* args = new (zone) ZoneList<Expression*>(1, zone);
VariableProxy* generator = factory->NewVariableProxy(
parser_->function_state_->generator_object_variable());
args->Add(generator, zone);
return factory->NewCallRuntime(Runtime::kInlineGeneratorGetInput, args, pos);
}
Literal* ParserTraits::ExpressionFromLiteral(Token::Value token, int pos,
Scanner* scanner,
AstNodeFactory* factory) {
switch (token) {
case Token::NULL_LITERAL:
return factory->NewNullLiteral(pos);
case Token::TRUE_LITERAL:
return factory->NewBooleanLiteral(true, pos);
case Token::FALSE_LITERAL:
return factory->NewBooleanLiteral(false, pos);
case Token::SMI: {
int value = scanner->smi_value();
return factory->NewSmiLiteral(value, pos);
}
case Token::NUMBER: {
bool has_dot = scanner->ContainsDot();
double value = scanner->DoubleValue();
return factory->NewNumberLiteral(value, pos, has_dot);
}
default:
DCHECK(false);
}
return NULL;
}
Expression* ParserTraits::ExpressionFromIdentifier(const AstRawString* name,
int start_position,
int end_position,
Scope* scope,
AstNodeFactory* factory) {
if (parser_->fni_ != NULL) parser_->fni_->PushVariableName(name);
return scope->NewUnresolved(factory, name, Variable::NORMAL, start_position,
end_position);
}
Expression* ParserTraits::ExpressionFromString(int pos, Scanner* scanner,
AstNodeFactory* factory) {
const AstRawString* symbol = GetSymbol(scanner);
if (parser_->fni_ != NULL) parser_->fni_->PushLiteralName(symbol);
return factory->NewStringLiteral(symbol, pos);
}
Expression* ParserTraits::GetIterator(Expression* iterable,
AstNodeFactory* factory, int pos) {
Expression* iterator_symbol_literal =
factory->NewSymbolLiteral("iterator_symbol", RelocInfo::kNoPosition);
Expression* prop =
factory->NewProperty(iterable, iterator_symbol_literal, pos);
Zone* zone = parser_->zone();
ZoneList<Expression*>* args = new (zone) ZoneList<Expression*>(0, zone);
return factory->NewCall(prop, args, pos);
}
Literal* ParserTraits::GetLiteralTheHole(int position,
AstNodeFactory* factory) {
return factory->NewTheHoleLiteral(RelocInfo::kNoPosition);
}
Expression* ParserTraits::ParseV8Intrinsic(bool* ok) {
return parser_->ParseV8Intrinsic(ok);
}
FunctionLiteral* ParserTraits::ParseFunctionLiteral(
const AstRawString* name, Scanner::Location function_name_location,
FunctionNameValidity function_name_validity, FunctionKind kind,
int function_token_position, FunctionLiteral::FunctionType type,
LanguageMode language_mode, bool* ok) {
return parser_->ParseFunctionLiteral(
name, function_name_location, function_name_validity, kind,
function_token_position, type, language_mode, ok);
}
ClassLiteral* ParserTraits::ParseClassLiteral(
Type::ExpressionClassifier* classifier, const AstRawString* name,
Scanner::Location class_name_location, bool name_is_strict_reserved,
int pos, bool* ok) {
return parser_->ParseClassLiteral(classifier, name, class_name_location,
name_is_strict_reserved, pos, ok);
}
void ParserTraits::MarkTailPosition(Expression* expression) {
expression->MarkTail();
}
void ParserTraits::MarkCollectedTailCallExpressions() {
parser_->MarkCollectedTailCallExpressions();
}
Parser::Parser(ParseInfo* info)
: ParserBase<ParserTraits>(info->zone(), &scanner_, info->stack_limit(),
info->extension(), info->ast_value_factory(),
NULL, this),
scanner_(info->unicode_cache()),
reusable_preparser_(NULL),
original_scope_(NULL),
target_stack_(NULL),
compile_options_(info->compile_options()),
cached_parse_data_(NULL),
total_preparse_skipped_(0),
pre_parse_timer_(NULL),
parsing_on_main_thread_(true) {
// Even though we were passed ParseInfo, we should not store it in
// Parser - this makes sure that Isolate is not accidentally accessed via
// ParseInfo during background parsing.
DCHECK(!info->script().is_null() || info->source_stream() != NULL);
set_allow_lazy(info->allow_lazy_parsing());
set_allow_natives(FLAG_allow_natives_syntax || info->is_native());
set_allow_tailcalls(FLAG_harmony_tailcalls && !info->is_native() &&
info->isolate()->is_tail_call_elimination_enabled());
set_allow_harmony_do_expressions(FLAG_harmony_do_expressions);
set_allow_harmony_for_in(FLAG_harmony_for_in);
set_allow_harmony_function_name(FLAG_harmony_function_name);
set_allow_harmony_function_sent(FLAG_harmony_function_sent);
set_allow_harmony_restrictive_declarations(
FLAG_harmony_restrictive_declarations);
set_allow_harmony_exponentiation_operator(
FLAG_harmony_exponentiation_operator);
set_allow_harmony_async_await(FLAG_harmony_async_await);
set_allow_harmony_restrictive_generators(FLAG_harmony_restrictive_generators);
for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
++feature) {
use_counts_[feature] = 0;
}
if (info->ast_value_factory() == NULL) {
// info takes ownership of AstValueFactory.
info->set_ast_value_factory(new AstValueFactory(zone(), info->hash_seed()));
info->set_ast_value_factory_owned();
ast_value_factory_ = info->ast_value_factory();
}
}
FunctionLiteral* Parser::ParseProgram(Isolate* isolate, ParseInfo* info) {
// TODO(bmeurer): We temporarily need to pass allow_nesting = true here,
// see comment for HistogramTimerScope class.
// It's OK to use the Isolate & counters here, since this function is only
// called in the main thread.
DCHECK(parsing_on_main_thread_);
HistogramTimerScope timer_scope(isolate->counters()->parse(), true);
RuntimeCallTimerScope runtime_timer(isolate, &RuntimeCallStats::Parse);
TRACE_EVENT0("v8", "V8.Parse");
Handle<String> source(String::cast(info->script()->source()));
isolate->counters()->total_parse_size()->Increment(source->length());
base::ElapsedTimer timer;
if (FLAG_trace_parse) {
timer.Start();
}
fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
// Initialize parser state.
CompleteParserRecorder recorder;
if (produce_cached_parse_data()) {
log_ = &recorder;
} else if (consume_cached_parse_data()) {
cached_parse_data_->Initialize();
}
source = String::Flatten(source);
FunctionLiteral* result;
if (source->IsExternalTwoByteString()) {
// Notice that the stream is destroyed at the end of the branch block.
// The last line of the blocks can't be moved outside, even though they're
// identical calls.
ExternalTwoByteStringUtf16CharacterStream stream(
Handle<ExternalTwoByteString>::cast(source), 0, source->length());
scanner_.Initialize(&stream);
result = DoParseProgram(info);
} else {
GenericStringUtf16CharacterStream stream(source, 0, source->length());
scanner_.Initialize(&stream);
result = DoParseProgram(info);
}
if (result != NULL) {
DCHECK_EQ(scanner_.peek_location().beg_pos, source->length());
}
HandleSourceURLComments(isolate, info->script());
if (FLAG_trace_parse && result != NULL) {
double ms = timer.Elapsed().InMillisecondsF();
if (info->is_eval()) {
PrintF("[parsing eval");
} else if (info->script()->name()->IsString()) {
String* name = String::cast(info->script()->name());
base::SmartArrayPointer<char> name_chars = name->ToCString();
PrintF("[parsing script: %s", name_chars.get());
} else {
PrintF("[parsing script");
}
PrintF(" - took %0.3f ms]\n", ms);
}
if (produce_cached_parse_data()) {
if (result != NULL) *info->cached_data() = recorder.GetScriptData();
log_ = NULL;
}
return result;
}
FunctionLiteral* Parser::DoParseProgram(ParseInfo* info) {
// Note that this function can be called from the main thread or from a
// background thread. We should not access anything Isolate / heap dependent
// via ParseInfo, and also not pass it forward.
DCHECK(scope_ == NULL);
DCHECK(target_stack_ == NULL);
Mode parsing_mode = FLAG_lazy && allow_lazy() ? PARSE_LAZILY : PARSE_EAGERLY;
if (allow_natives() || extension_ != NULL) parsing_mode = PARSE_EAGERLY;
FunctionLiteral* result = NULL;
{
// TODO(wingo): Add an outer SCRIPT_SCOPE corresponding to the native
// context, which will have the "this" binding for script scopes.
Scope* scope = NewScope(scope_, SCRIPT_SCOPE);
info->set_script_scope(scope);
if (!info->context().is_null() && !info->context()->IsNativeContext()) {
scope = Scope::DeserializeScopeChain(info->isolate(), zone(),
*info->context(), scope);
// The Scope is backed up by ScopeInfo (which is in the V8 heap); this
// means the Parser cannot operate independent of the V8 heap. Tell the
// string table to internalize strings and values right after they're
// created. This kind of parsing can only be done in the main thread.
DCHECK(parsing_on_main_thread_);
ast_value_factory()->Internalize(info->isolate());
}
original_scope_ = scope;
if (info->is_eval()) {
if (!scope->is_script_scope() || is_strict(info->language_mode())) {
parsing_mode = PARSE_EAGERLY;
}
scope = NewScope(scope, EVAL_SCOPE);
} else if (info->is_module()) {
scope = NewScope(scope, MODULE_SCOPE);
}
scope->set_start_position(0);
// Enter 'scope' with the given parsing mode.
ParsingModeScope parsing_mode_scope(this, parsing_mode);
AstNodeFactory function_factory(ast_value_factory());
FunctionState function_state(&function_state_, &scope_, scope,
kNormalFunction, &function_factory);
ZoneList<Statement*>* body = new(zone()) ZoneList<Statement*>(16, zone());
bool ok = true;
int beg_pos = scanner()->location().beg_pos;
parsing_module_ = info->is_module();
if (parsing_module_) {
ParseModuleItemList(body, &ok);
} else {
// Don't count the mode in the use counters--give the program a chance
// to enable script-wide strict mode below.
scope_->SetLanguageMode(info->language_mode());
ParseStatementList(body, Token::EOS, &ok);
}
// The parser will peek but not consume EOS. Our scope logically goes all
// the way to the EOS, though.
scope->set_end_position(scanner()->peek_location().beg_pos);
if (ok && is_strict(language_mode())) {
CheckStrictOctalLiteral(beg_pos, scanner()->location().end_pos, &ok);
CheckDecimalLiteralWithLeadingZero(use_counts_, beg_pos,
scanner()->location().end_pos);
}
if (ok && is_sloppy(language_mode())) {
// TODO(littledan): Function bindings on the global object that modify
// pre-existing bindings should be made writable, enumerable and
// nonconfigurable if possible, whereas this code will leave attributes
// unchanged if the property already exists.
InsertSloppyBlockFunctionVarBindings(scope, &ok);
}
if (ok) {
CheckConflictingVarDeclarations(scope_, &ok);
}
if (ok && info->parse_restriction() == ONLY_SINGLE_FUNCTION_LITERAL) {
if (body->length() != 1 ||
!body->at(0)->IsExpressionStatement() ||
!body->at(0)->AsExpressionStatement()->
expression()->IsFunctionLiteral()) {
ReportMessage(MessageTemplate::kSingleFunctionLiteral);
ok = false;
}
}
if (ok) {
ParserTraits::RewriteDestructuringAssignments();
result = factory()->NewScriptOrEvalFunctionLiteral(
scope_, body, function_state.materialized_literal_count(),
function_state.expected_property_count());
}
}
// Make sure the target stack is empty.
DCHECK(target_stack_ == NULL);
return result;
}
FunctionLiteral* Parser::ParseLazy(Isolate* isolate, ParseInfo* info) {
// It's OK to use the Isolate & counters here, since this function is only
// called in the main thread.
DCHECK(parsing_on_main_thread_);
RuntimeCallTimerScope runtime_timer(isolate, &RuntimeCallStats::ParseLazy);
HistogramTimerScope timer_scope(isolate->counters()->parse_lazy());
TRACE_EVENT0("v8", "V8.ParseLazy");
Handle<String> source(String::cast(info->script()->source()));
isolate->counters()->total_parse_size()->Increment(source->length());
base::ElapsedTimer timer;
if (FLAG_trace_parse) {
timer.Start();
}
Handle<SharedFunctionInfo> shared_info = info->shared_info();
// Initialize parser state.
source = String::Flatten(source);
FunctionLiteral* result;
if (source->IsExternalTwoByteString()) {
ExternalTwoByteStringUtf16CharacterStream stream(
Handle<ExternalTwoByteString>::cast(source),
shared_info->start_position(),
shared_info->end_position());
result = ParseLazy(isolate, info, &stream);
} else {
GenericStringUtf16CharacterStream stream(source,
shared_info->start_position(),
shared_info->end_position());
result = ParseLazy(isolate, info, &stream);
}
if (FLAG_trace_parse && result != NULL) {
double ms = timer.Elapsed().InMillisecondsF();
base::SmartArrayPointer<char> name_chars =
result->debug_name()->ToCString();
PrintF("[parsing function: %s - took %0.3f ms]\n", name_chars.get(), ms);
}
return result;
}
static FunctionLiteral::FunctionType ComputeFunctionType(
Handle<SharedFunctionInfo> shared_info) {
if (shared_info->is_declaration()) {
return FunctionLiteral::kDeclaration;
} else if (shared_info->is_named_expression()) {
return FunctionLiteral::kNamedExpression;
} else if (IsConciseMethod(shared_info->kind()) ||
IsAccessorFunction(shared_info->kind())) {
return FunctionLiteral::kAccessorOrMethod;
}
return FunctionLiteral::kAnonymousExpression;
}
FunctionLiteral* Parser::ParseLazy(Isolate* isolate, ParseInfo* info,
Utf16CharacterStream* source) {
Handle<SharedFunctionInfo> shared_info = info->shared_info();
scanner_.Initialize(source);
DCHECK(scope_ == NULL);
DCHECK(target_stack_ == NULL);
Handle<String> name(String::cast(shared_info->name()));
DCHECK(ast_value_factory());
fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
const AstRawString* raw_name = ast_value_factory()->GetString(name);
fni_->PushEnclosingName(raw_name);
ParsingModeScope parsing_mode(this, PARSE_EAGERLY);
// Place holder for the result.
FunctionLiteral* result = NULL;
{
// Parse the function literal.
Scope* scope = NewScope(scope_, SCRIPT_SCOPE);
info->set_script_scope(scope);
if (!info->context().is_null()) {
// Ok to use Isolate here, since lazy function parsing is only done in the
// main thread.
DCHECK(parsing_on_main_thread_);
scope = Scope::DeserializeScopeChain(isolate, zone(), *info->context(),
scope);
}
original_scope_ = scope;
AstNodeFactory function_factory(ast_value_factory());
FunctionState function_state(&function_state_, &scope_, scope,
shared_info->kind(), &function_factory);
DCHECK(is_sloppy(scope->language_mode()) ||
is_strict(info->language_mode()));
DCHECK(info->language_mode() == shared_info->language_mode());
FunctionLiteral::FunctionType function_type =
ComputeFunctionType(shared_info);
bool ok = true;
if (shared_info->is_arrow()) {
bool is_async = allow_harmony_async_await() && shared_info->is_async();
if (is_async) {
DCHECK(!scanner()->HasAnyLineTerminatorAfterNext());
Consume(Token::ASYNC);
DCHECK(peek_any_identifier() || peek() == Token::LPAREN);
}
// TODO(adamk): We should construct this scope from the ScopeInfo.
Scope* scope =
NewScope(scope_, FUNCTION_SCOPE, FunctionKind::kArrowFunction);
// These two bits only need to be explicitly set because we're
// not passing the ScopeInfo to the Scope constructor.
// TODO(adamk): Remove these calls once the above NewScope call
// passes the ScopeInfo.
if (shared_info->scope_info()->CallsEval()) {
scope->RecordEvalCall();
}
SetLanguageMode(scope, shared_info->language_mode());
scope->set_start_position(shared_info->start_position());
ExpressionClassifier formals_classifier(this);
ParserFormalParameters formals(scope);
Checkpoint checkpoint(this);
{
// Parsing patterns as variable reference expression creates
// NewUnresolved references in current scope. Entrer arrow function
// scope for formal parameter parsing.
BlockState block_state(&scope_, scope);
if (Check(Token::LPAREN)) {
// '(' StrictFormalParameters ')'
ParseFormalParameterList(&formals, &formals_classifier, &ok);
if (ok) ok = Check(Token::RPAREN);
} else {
// BindingIdentifier
ParseFormalParameter(&formals, &formals_classifier, &ok);
if (ok) {
DeclareFormalParameter(formals.scope, formals.at(0),
&formals_classifier);
}
}
}
if (ok) {
checkpoint.Restore(&formals.materialized_literals_count);
// Pass `accept_IN=true` to ParseArrowFunctionLiteral --- This should
// not be observable, or else the preparser would have failed.
Expression* expression = ParseArrowFunctionLiteral(
true, formals, is_async, formals_classifier, &ok);
if (ok) {
// Scanning must end at the same position that was recorded
// previously. If not, parsing has been interrupted due to a stack
// overflow, at which point the partially parsed arrow function
// concise body happens to be a valid expression. This is a problem
// only for arrow functions with single expression bodies, since there
// is no end token such as "}" for normal functions.
if (scanner()->location().end_pos == shared_info->end_position()) {
// The pre-parser saw an arrow function here, so the full parser
// must produce a FunctionLiteral.
DCHECK(expression->IsFunctionLiteral());
result = expression->AsFunctionLiteral();
} else {
ok = false;
}
}
}
} else if (shared_info->is_default_constructor()) {
result = DefaultConstructor(
raw_name, IsSubclassConstructor(shared_info->kind()), scope,
shared_info->start_position(), shared_info->end_position(),
shared_info->language_mode());
} else {
result = ParseFunctionLiteral(raw_name, Scanner::Location::invalid(),
kSkipFunctionNameCheck, shared_info->kind(),
RelocInfo::kNoPosition, function_type,
shared_info->language_mode(), &ok);
}
// Make sure the results agree.
DCHECK(ok == (result != NULL));
}
// Make sure the target stack is empty.
DCHECK(target_stack_ == NULL);
if (result != NULL) {
Handle<String> inferred_name(shared_info->inferred_name());
result->set_inferred_name(inferred_name);
}
return result;
}
void* Parser::ParseStatementList(ZoneList<Statement*>* body, int end_token,
bool* ok) {
// StatementList ::
// (StatementListItem)* <end_token>
// Allocate a target stack to use for this set of source
// elements. This way, all scripts and functions get their own
// target stack thus avoiding illegal breaks and continues across
// functions.
TargetScope scope(&this->target_stack_);
DCHECK(body != NULL);
bool directive_prologue = true; // Parsing directive prologue.
while (peek() != end_token) {
if (directive_prologue && peek() != Token::STRING) {
directive_prologue = false;
}
Scanner::Location token_loc = scanner()->peek_location();
Statement* stat = ParseStatementListItem(CHECK_OK);
if (stat == NULL || stat->IsEmpty()) {
directive_prologue = false; // End of directive prologue.
continue;
}
if (directive_prologue) {
// A shot at a directive.
ExpressionStatement* e_stat;
Literal* literal;
// Still processing directive prologue?
if ((e_stat = stat->AsExpressionStatement()) != NULL &&
(literal = e_stat->expression()->AsLiteral()) != NULL &&
literal->raw_value()->IsString()) {
// Check "use strict" directive (ES5 14.1), "use asm" directive.
bool use_strict_found =
literal->raw_value()->AsString() ==
ast_value_factory()->use_strict_string() &&
token_loc.end_pos - token_loc.beg_pos ==
ast_value_factory()->use_strict_string()->length() + 2;
if (use_strict_found) {
if (is_sloppy(scope_->language_mode())) {
RaiseLanguageMode(STRICT);
}
if (!scope_->HasSimpleParameters()) {
// TC39 deemed "use strict" directives to be an error when occurring
// in the body of a function with non-simple parameter list, on
// 29/7/2015. https://goo.gl/ueA7Ln
const AstRawString* string = literal->raw_value()->AsString();
ParserTraits::ReportMessageAt(
token_loc, MessageTemplate::kIllegalLanguageModeDirective,
string);
*ok = false;
return nullptr;
}
// Because declarations in strict eval code don't leak into the scope
// of the eval call, it is likely that functions declared in strict
// eval code will be used within the eval code, so lazy parsing is
// probably not a win.
if (scope_->is_eval_scope()) mode_ = PARSE_EAGERLY;
} else if (literal->raw_value()->AsString() ==
ast_value_factory()->use_asm_string() &&
token_loc.end_pos - token_loc.beg_pos ==
ast_value_factory()->use_asm_string()->length() + 2) {
// Store the usage count; The actual use counter on the isolate is
// incremented after parsing is done.
++use_counts_[v8::Isolate::kUseAsm];
scope_->SetAsmModule();
} else {
// Should not change mode, but will increment UseCounter
// if appropriate. Ditto usages below.
RaiseLanguageMode(SLOPPY);
}
} else {
// End of the directive prologue.
directive_prologue = false;
RaiseLanguageMode(SLOPPY);
}
} else {
RaiseLanguageMode(SLOPPY);
}
body->Add(stat, zone());
}
return 0;
}
Statement* Parser::ParseStatementListItem(bool* ok) {
// (Ecma 262 6th Edition, 13.1):
// StatementListItem:
// Statement
// Declaration
const Token::Value peeked = peek();
switch (peeked) {
case Token::FUNCTION:
return ParseHoistableDeclaration(NULL, ok);
case Token::CLASS:
Consume(Token::CLASS);
return ParseClassDeclaration(NULL, ok);
case Token::CONST:
return ParseVariableStatement(kStatementListItem, NULL, ok);
case Token::VAR:
return ParseVariableStatement(kStatementListItem, NULL, ok);
case Token::LET:
if (IsNextLetKeyword()) {
return ParseVariableStatement(kStatementListItem, NULL, ok);
}
break;
case Token::ASYNC:
if (allow_harmony_async_await() && PeekAhead() == Token::FUNCTION &&
!scanner()->HasAnyLineTerminatorAfterNext()) {
Consume(Token::ASYNC);
return ParseAsyncFunctionDeclaration(NULL, ok);
}
/* falls through */
default:
break;
}
return ParseStatement(NULL, kAllowLabelledFunctionStatement, ok);
}
Statement* Parser::ParseModuleItem(bool* ok) {
// (Ecma 262 6th Edition, 15.2):
// ModuleItem :
// ImportDeclaration
// ExportDeclaration
// StatementListItem
switch (peek()) {
case Token::IMPORT:
return ParseImportDeclaration(ok);
case Token::EXPORT:
return ParseExportDeclaration(ok);
default:
return ParseStatementListItem(ok);
}
}
void* Parser::ParseModuleItemList(ZoneList<Statement*>* body, bool* ok) {
// (Ecma 262 6th Edition, 15.2):
// Module :
// ModuleBody?
//
// ModuleBody :
// ModuleItem*
DCHECK(scope_->is_module_scope());
while (peek() != Token::EOS) {
Statement* stat = ParseModuleItem(CHECK_OK);
if (stat && !stat->IsEmpty()) {
body->Add(stat, zone());
}
}
// Check that all exports are bound.
ModuleDescriptor* descriptor = scope_->module();
for (ModuleDescriptor::Iterator it = descriptor->iterator(); !it.done();
it.Advance()) {
if (scope_->LookupLocal(it.local_name()) == NULL) {
// TODO(adamk): Pass both local_name and export_name once ParserTraits
// supports multiple arg error messages.
// Also try to report this at a better location.
ParserTraits::ReportMessage(MessageTemplate::kModuleExportUndefined,
it.local_name());
*ok = false;
return NULL;
}
}
return NULL;
}
const AstRawString* Parser::ParseModuleSpecifier(bool* ok) {
// ModuleSpecifier :
// StringLiteral
Expect(Token::STRING, CHECK_OK);
return GetSymbol(scanner());
}
void* Parser::ParseExportClause(ZoneList<const AstRawString*>* export_names,
ZoneList<Scanner::Location>* export_locations,
ZoneList<const AstRawString*>* local_names,
Scanner::Location* reserved_loc, bool* ok) {
// ExportClause :
// '{' '}'
// '{' ExportsList '}'
// '{' ExportsList ',' '}'
//
// ExportsList :
// ExportSpecifier
// ExportsList ',' ExportSpecifier
//
// ExportSpecifier :
// IdentifierName
// IdentifierName 'as' IdentifierName
Expect(Token::LBRACE, CHECK_OK);
Token::Value name_tok;
while ((name_tok = peek()) != Token::RBRACE) {
// Keep track of the first reserved word encountered in case our
// caller needs to report an error.
if (!reserved_loc->IsValid() &&
!Token::IsIdentifier(name_tok, STRICT, false, parsing_module_)) {
*reserved_loc = scanner()->location();
}
const AstRawString* local_name = ParseIdentifierName(CHECK_OK);
const AstRawString* export_name = NULL;
if (CheckContextualKeyword(CStrVector("as"))) {
export_name = ParseIdentifierName(CHECK_OK);
}
if (export_name == NULL) {
export_name = local_name;
}
export_names->Add(export_name, zone());
local_names->Add(local_name, zone());
export_locations->Add(scanner()->location(), zone());
if (peek() == Token::RBRACE) break;
Expect(Token::COMMA, CHECK_OK);
}
Expect(Token::RBRACE, CHECK_OK);
return 0;
}
ZoneList<ImportDeclaration*>* Parser::ParseNamedImports(int pos, bool* ok) {
// NamedImports :
// '{' '}'
// '{' ImportsList '}'
// '{' ImportsList ',' '}'
//
// ImportsList :
// ImportSpecifier
// ImportsList ',' ImportSpecifier
//
// ImportSpecifier :
// BindingIdentifier
// IdentifierName 'as' BindingIdentifier
Expect(Token::LBRACE, CHECK_OK);
ZoneList<ImportDeclaration*>* result =
new (zone()) ZoneList<ImportDeclaration*>(1, zone());
while (peek() != Token::RBRACE) {
const AstRawString* import_name = ParseIdentifierName(CHECK_OK);
const AstRawString* local_name = import_name;
// In the presence of 'as', the left-side of the 'as' can
// be any IdentifierName. But without 'as', it must be a valid
// BindingIdentifier.
if (CheckContextualKeyword(CStrVector("as"))) {
local_name = ParseIdentifierName(CHECK_OK);
}
if (!Token::IsIdentifier(scanner()->current_token(), STRICT, false,
parsing_module_)) {
*ok = false;
ReportMessage(MessageTemplate::kUnexpectedReserved);
return NULL;
} else if (IsEvalOrArguments(local_name)) {
*ok = false;
ReportMessage(MessageTemplate::kStrictEvalArguments);
return NULL;
}
VariableProxy* proxy = NewUnresolved(local_name, CONST);
ImportDeclaration* declaration =
factory()->NewImportDeclaration(proxy, import_name, NULL, scope_, pos);
Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
result->Add(declaration, zone());
if (peek() == Token::RBRACE) break;
Expect(Token::COMMA, CHECK_OK);
}
Expect(Token::RBRACE, CHECK_OK);
return result;
}
Statement* Parser::ParseImportDeclaration(bool* ok) {
// ImportDeclaration :
// 'import' ImportClause 'from' ModuleSpecifier ';'
// 'import' ModuleSpecifier ';'
//
// ImportClause :
// NameSpaceImport
// NamedImports
// ImportedDefaultBinding
// ImportedDefaultBinding ',' NameSpaceImport
// ImportedDefaultBinding ',' NamedImports
//
// NameSpaceImport :
// '*' 'as' ImportedBinding
int pos = peek_position();
Expect(Token::IMPORT, CHECK_OK);
Token::Value tok = peek();
// 'import' ModuleSpecifier ';'
if (tok == Token::STRING) {
const AstRawString* module_specifier = ParseModuleSpecifier(CHECK_OK);
scope_->module()->AddModuleRequest(module_specifier, zone());
ExpectSemicolon(CHECK_OK);
return factory()->NewEmptyStatement(pos);
}
// Parse ImportedDefaultBinding if present.
ImportDeclaration* import_default_declaration = NULL;
if (tok != Token::MUL && tok != Token::LBRACE) {
const AstRawString* local_name =
ParseIdentifier(kDontAllowRestrictedIdentifiers, CHECK_OK);
VariableProxy* proxy = NewUnresolved(local_name, CONST);
import_default_declaration = factory()->NewImportDeclaration(
proxy, ast_value_factory()->default_string(), NULL, scope_, pos);
Declare(import_default_declaration, DeclarationDescriptor::NORMAL, true,
CHECK_OK);
}
const AstRawString* module_instance_binding = NULL;
ZoneList<ImportDeclaration*>* named_declarations = NULL;
if (import_default_declaration == NULL || Check(Token::COMMA)) {
switch (peek()) {
case Token::MUL: {
Consume(Token::MUL);
ExpectContextualKeyword(CStrVector("as"), CHECK_OK);
module_instance_binding =
ParseIdentifier(kDontAllowRestrictedIdentifiers, CHECK_OK);
// TODO(ES6): Add an appropriate declaration.
break;
}
case Token::LBRACE:
named_declarations = ParseNamedImports(pos, CHECK_OK);
break;
default:
*ok = false;
ReportUnexpectedToken(scanner()->current_token());
return NULL;
}
}
ExpectContextualKeyword(CStrVector("from"), CHECK_OK);
const AstRawString* module_specifier = ParseModuleSpecifier(CHECK_OK);
scope_->module()->AddModuleRequest(module_specifier, zone());
if (module_instance_binding != NULL) {
// TODO(ES6): Set the module specifier for the module namespace binding.
}
if (import_default_declaration != NULL) {
import_default_declaration->set_module_specifier(module_specifier);
}
if (named_declarations != NULL) {
for (int i = 0; i < named_declarations->length(); ++i) {
named_declarations->at(i)->set_module_specifier(module_specifier);
}
}
ExpectSemicolon(CHECK_OK);
return factory()->NewEmptyStatement(pos);
}
Statement* Parser::ParseExportDefault(bool* ok) {
// Supports the following productions, starting after the 'default' token:
// 'export' 'default' FunctionDeclaration
// 'export' 'default' ClassDeclaration
// 'export' 'default' AssignmentExpression[In] ';'
Expect(Token::DEFAULT, CHECK_OK);
Scanner::Location default_loc = scanner()->location();
const AstRawString* default_string = ast_value_factory()->default_string();
ZoneList<const AstRawString*> names(1, zone());
Statement* result = nullptr;
Expression* default_export = nullptr;
switch (peek()) {
case Token::FUNCTION: {
Consume(Token::FUNCTION);
int pos = position();
bool is_generator = Check(Token::MUL);
if (peek() == Token::LPAREN) {
// FunctionDeclaration[+Default] ::
// 'function' '(' FormalParameters ')' '{' FunctionBody '}'
//
// GeneratorDeclaration[+Default] ::
// 'function' '*' '(' FormalParameters ')' '{' FunctionBody '}'
default_export = ParseFunctionLiteral(
default_string, Scanner::Location::invalid(),
kSkipFunctionNameCheck,
is_generator ? FunctionKind::kGeneratorFunction
: FunctionKind::kNormalFunction,
pos, FunctionLiteral::kDeclaration, language_mode(), CHECK_OK);
result = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
} else {
result = ParseHoistableDeclaration(
pos, is_generator ? ParseFunctionFlags::kIsGenerator
: ParseFunctionFlags::kIsNormal,
&names, CHECK_OK);
}
break;
}
case Token::CLASS:
Consume(Token::CLASS);
if (peek() == Token::EXTENDS || peek() == Token::LBRACE) {
// ClassDeclaration[+Default] ::
// 'class' ('extends' LeftHandExpression)? '{' ClassBody '}'
default_export = ParseClassLiteral(nullptr, default_string,
Scanner::Location::invalid(), false,
position(), CHECK_OK);
result = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
} else {
result = ParseClassDeclaration(&names, CHECK_OK);
}
break;
case Token::ASYNC:
if (allow_harmony_async_await() && PeekAhead() == Token::FUNCTION &&
!scanner()->HasAnyLineTerminatorAfterNext()) {
Consume(Token::ASYNC);
Consume(Token::FUNCTION);
int pos = position();
if (peek() == Token::LPAREN) {
// AsyncFunctionDeclaration[+Default] ::
// async [no LineTerminator here] function ( FormalParameters ) {
// AsyncFunctionBody
// }
default_export = ParseFunctionLiteral(
default_string, Scanner::Location::invalid(),
kSkipFunctionNameCheck, FunctionKind::kAsyncFunction, pos,
FunctionLiteral::kDeclaration, language_mode(), CHECK_OK);
result = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
} else {
result = ParseHoistableDeclaration(pos, ParseFunctionFlags::kIsAsync,
&names, CHECK_OK);
}
break;
}
/* falls through */
default: {
int pos = peek_position();
ExpressionClassifier classifier(this);
Expression* expr = ParseAssignmentExpression(true, &classifier, CHECK_OK);
RewriteNonPattern(&classifier, CHECK_OK);
ExpectSemicolon(CHECK_OK);
result = factory()->NewExpressionStatement(expr, pos);
break;
}
}
DCHECK_LE(names.length(), 1);
if (names.length() == 1) {
scope_->module()->AddLocalExport(default_string, names.first(), zone(), ok);
if (!*ok) {
ParserTraits::ReportMessageAt(
default_loc, MessageTemplate::kDuplicateExport, default_string);
return nullptr;
}
} else {
// TODO(ES6): Assign result to a const binding with the name "*default*"
// and add an export entry with "*default*" as the local name.
USE(default_export);
}
return result;
}
Statement* Parser::ParseExportDeclaration(bool* ok) {
// ExportDeclaration:
// 'export' '*' 'from' ModuleSpecifier ';'
// 'export' ExportClause ('from' ModuleSpecifier)? ';'
// 'export' VariableStatement
// 'export' Declaration
// 'export' 'default' ... (handled in ParseExportDefault)
int pos = peek_position();
Expect(Token::EXPORT, CHECK_OK);
Statement* result = NULL;
ZoneList<const AstRawString*> names(1, zone());
switch (peek()) {
case Token::DEFAULT:
return ParseExportDefault(ok);
case Token::MUL: {
Consume(Token::MUL);
ExpectContextualKeyword(CStrVector("from"), CHECK_OK);
const AstRawString* module_specifier = ParseModuleSpecifier(CHECK_OK);
scope_->module()->AddModuleRequest(module_specifier, zone());
// TODO(ES6): scope_->module()->AddStarExport(...)
ExpectSemicolon(CHECK_OK);
return factory()->NewEmptyStatement(pos);
}
case Token::LBRACE: {
// There are two cases here:
//
// 'export' ExportClause ';'
// and
// 'export' ExportClause FromClause ';'
//
// In the first case, the exported identifiers in ExportClause must
// not be reserved words, while in the latter they may be. We
// pass in a location that gets filled with the first reserved word
// encountered, and then throw a SyntaxError if we are in the
// non-FromClause case.
Scanner::Location reserved_loc = Scanner::Location::invalid();
ZoneList<const AstRawString*> export_names(1, zone());
ZoneList<Scanner::Location> export_locations(1, zone());
ZoneList<const AstRawString*> local_names(1, zone());
ParseExportClause(&export_names, &export_locations, &local_names,
&reserved_loc, CHECK_OK);
const AstRawString* indirect_export_module_specifier = NULL;
if (CheckContextualKeyword(CStrVector("from"))) {
indirect_export_module_specifier = ParseModuleSpecifier(CHECK_OK);
} else if (reserved_loc.IsValid()) {
// No FromClause, so reserved words are invalid in ExportClause.
*ok = false;
ReportMessageAt(reserved_loc, MessageTemplate::kUnexpectedReserved);
return NULL;
}
ExpectSemicolon(CHECK_OK);
const int length = export_names.length();
DCHECK_EQ(length, local_names.length());
DCHECK_EQ(length, export_locations.length());
if (indirect_export_module_specifier == NULL) {
for (int i = 0; i < length; ++i) {
scope_->module()->AddLocalExport(export_names[i], local_names[i],
zone(), ok);
if (!*ok) {
ParserTraits::ReportMessageAt(export_locations[i],
MessageTemplate::kDuplicateExport,
export_names[i]);
return NULL;
}
}
} else {
scope_->module()->AddModuleRequest(indirect_export_module_specifier,
zone());
for (int i = 0; i < length; ++i) {
// TODO(ES6): scope_->module()->AddIndirectExport(...);(
}
}
return factory()->NewEmptyStatement(pos);
}
case Token::FUNCTION:
result = ParseHoistableDeclaration(&names, CHECK_OK);
break;
case Token::CLASS:
Consume(Token::CLASS);
result = ParseClassDeclaration(&names, CHECK_OK);
break;
case Token::VAR:
case Token::LET:
case Token::CONST:
result = ParseVariableStatement(kStatementListItem, &names, CHECK_OK);
break;
case Token::ASYNC:
if (allow_harmony_async_await()) {
Consume(Token::ASYNC);
result = ParseAsyncFunctionDeclaration(&names, CHECK_OK);
break;
}
/* falls through */
default:
*ok = false;
ReportUnexpectedToken(scanner()->current_token());
return NULL;
}
// Extract declared names into export declarations.
ModuleDescriptor* descriptor = scope_->module();
for (int i = 0; i < names.length(); ++i) {
descriptor->AddLocalExport(names[i], names[i], zone(), ok);
if (!*ok) {
// TODO(adamk): Possibly report this error at the right place.
ParserTraits::ReportMessage(MessageTemplate::kDuplicateExport, names[i]);
return NULL;
}
}
DCHECK_NOT_NULL(result);
return result;
}
Statement* Parser::ParseStatement(ZoneList<const AstRawString*>* labels,
AllowLabelledFunctionStatement allow_function,
bool* ok) {
// Statement ::
// EmptyStatement
// ...
if (peek() == Token::SEMICOLON) {
Next();
return factory()->NewEmptyStatement(RelocInfo::kNoPosition);
}
return ParseSubStatement(labels, allow_function, ok);
}
Statement* Parser::ParseSubStatement(
ZoneList<const AstRawString*>* labels,
AllowLabelledFunctionStatement allow_function, bool* ok) {
// Statement ::
// Block
// VariableStatement
// EmptyStatement
// ExpressionStatement
// IfStatement
// IterationStatement
// ContinueStatement
// BreakStatement
// ReturnStatement
// WithStatement
// LabelledStatement
// SwitchStatement
// ThrowStatement
// TryStatement
// DebuggerStatement
// Note: Since labels can only be used by 'break' and 'continue'
// statements, which themselves are only valid within blocks,
// iterations or 'switch' statements (i.e., BreakableStatements),
// labels can be simply ignored in all other cases; except for
// trivial labeled break statements 'label: break label' which is
// parsed into an empty statement.
switch (peek()) {
case Token::LBRACE:
return ParseBlock(labels, ok);
case Token::SEMICOLON:
Next();
return factory()->NewEmptyStatement(RelocInfo::kNoPosition);
case Token::IF:
return ParseIfStatement(labels, ok);
case Token::DO:
return ParseDoWhileStatement(labels, ok);
case Token::WHILE:
return ParseWhileStatement(labels, ok);
case Token::FOR:
return ParseForStatement(labels, ok);
case Token::CONTINUE:
case Token::BREAK:
case Token::RETURN:
case Token::THROW:
case Token::TRY: {
// These statements must have their labels preserved in an enclosing
// block
if (labels == NULL) {
return ParseStatementAsUnlabelled(labels, ok);
} else {
Block* result =
factory()->NewBlock(labels, 1, false, RelocInfo::kNoPosition);
Target target(&this->target_stack_, result);
Statement* statement = ParseStatementAsUnlabelled(labels, CHECK_OK);
if (result) result->statements()->Add(statement, zone());
return result;
}
}
case Token::WITH:
return ParseWithStatement(labels, ok);
case Token::SWITCH:
return ParseSwitchStatement(labels, ok);
case Token::FUNCTION:
// FunctionDeclaration only allowed as a StatementListItem, not in
// an arbitrary Statement position. Exceptions such as
// ES#sec-functiondeclarations-in-ifstatement-statement-clauses
// are handled by calling ParseScopedStatement rather than
// ParseSubStatement directly.
ReportMessageAt(scanner()->peek_location(),
is_strict(language_mode())
? MessageTemplate::kStrictFunction
: MessageTemplate::kSloppyFunction);
*ok = false;
return nullptr;
case Token::DEBUGGER:
return ParseDebuggerStatement(ok);
case Token::VAR:
return ParseVariableStatement(kStatement, NULL, ok);
default:
return ParseExpressionOrLabelledStatement(labels, allow_function, ok);
}
}
Statement* Parser::ParseStatementAsUnlabelled(
ZoneList<const AstRawString*>* labels, bool* ok) {
switch (peek()) {
case Token::CONTINUE:
return ParseContinueStatement(ok);
case Token::BREAK:
return ParseBreakStatement(labels, ok);
case Token::RETURN:
return ParseReturnStatement(ok);
case Token::THROW:
return ParseThrowStatement(ok);
case Token::TRY:
return ParseTryStatement(ok);
default:
UNREACHABLE();
return NULL;
}
}
VariableProxy* Parser::NewUnresolved(const AstRawString* name,
VariableMode mode) {
// If we are inside a function, a declaration of a var/const variable is a
// truly local variable, and the scope of the variable is always the function
// scope.
// Let/const variables in harmony mode are always added to the immediately
// enclosing scope.
Scope* scope =
IsLexicalVariableMode(mode) ? scope_ : scope_->DeclarationScope();
return scope->NewUnresolved(factory(), name, Variable::NORMAL,
scanner()->location().beg_pos,
scanner()->location().end_pos);
}
Variable* Parser::Declare(Declaration* declaration,
DeclarationDescriptor::Kind declaration_kind,
bool resolve, bool* ok, Scope* scope) {
VariableProxy* proxy = declaration->proxy();
DCHECK(proxy->raw_name() != NULL);
const AstRawString* name = proxy->raw_name();
VariableMode mode = declaration->mode();
DCHECK(IsDeclaredVariableMode(mode) && mode != CONST_LEGACY);
bool is_function_declaration = declaration->IsFunctionDeclaration();
if (scope == nullptr) scope = scope_;
Scope* declaration_scope =
IsLexicalVariableMode(mode) ? scope : scope->DeclarationScope();
Variable* var = NULL;
// If a suitable scope exists, then we can statically declare this
// variable and also set its mode. In any case, a Declaration node
// will be added to the scope so that the declaration can be added
// to the corresponding activation frame at runtime if necessary.
// For instance, var declarations inside a sloppy eval scope need
// to be added to the calling function context. Similarly, strict
// mode eval scope and lexical eval bindings do not leak variable
// declarations to the caller's scope so we declare all locals, too.
if (declaration_scope->is_function_scope() ||
declaration_scope->is_block_scope() ||
declaration_scope->is_module_scope() ||
declaration_scope->is_script_scope() ||
(declaration_scope->is_eval_scope() &&
(is_strict(declaration_scope->language_mode()) ||
IsLexicalVariableMode(mode)))) {
// Declare the variable in the declaration scope.
var = declaration_scope->LookupLocal(name);
if (var == NULL) {
// Declare the name.
Variable::Kind kind = Variable::NORMAL;
if (is_function_declaration) {
kind = Variable::FUNCTION;
}
var = declaration_scope->DeclareLocal(
name, mode, declaration->initialization(), kind, kNotAssigned);
} else if (IsLexicalVariableMode(mode) ||
IsLexicalVariableMode(var->mode())) {
// Allow duplicate function decls for web compat, see bug 4693.
bool duplicate_allowed = false;
if (is_sloppy(language_mode()) && is_function_declaration &&
var->is_function()) {
DCHECK(IsLexicalVariableMode(mode) &&
IsLexicalVariableMode(var->mode()));
// If the duplication is allowed, then the var will show up
// in the SloppyBlockFunctionMap and the new FunctionKind
// will be a permitted duplicate.
FunctionKind function_kind =
declaration->AsFunctionDeclaration()->fun()->kind();
duplicate_allowed =
scope->DeclarationScope()->sloppy_block_function_map()->Lookup(
const_cast<AstRawString*>(name), name->hash()) != nullptr &&
!IsAsyncFunction(function_kind) &&
!(allow_harmony_restrictive_generators() &&
IsGeneratorFunction(function_kind));
}
if (duplicate_allowed) {
++use_counts_[v8::Isolate::kSloppyModeBlockScopedFunctionRedefinition];
} else {
// The name was declared in this scope before; check for conflicting
// re-declarations. We have a conflict if either of the declarations
// is not a var (in script scope, we also have to ignore legacy const
// for compatibility). There is similar code in runtime.cc in the
// Declare functions. The function CheckConflictingVarDeclarations
// checks for var and let bindings from different scopes whereas this
// is a check for conflicting declarations within the same scope. This
// check also covers the special case
//
// function () { let x; { var x; } }
//
// because the var declaration is hoisted to the function scope where
// 'x' is already bound.
DCHECK(IsDeclaredVariableMode(var->mode()));
// In harmony we treat re-declarations as early errors. See
// ES5 16 for a definition of early errors.
if (declaration_kind == DeclarationDescriptor::NORMAL) {
ParserTraits::ReportMessage(MessageTemplate::kVarRedeclaration, name);
} else {
ParserTraits::ReportMessage(MessageTemplate::kParamDupe);
}
*ok = false;
return nullptr;
}
} else if (mode == VAR) {
var->set_maybe_assigned();
}
} else if (declaration_scope->is_eval_scope() &&
is_sloppy(declaration_scope->language_mode()) &&
!IsLexicalVariableMode(mode)) {
// In a var binding in a sloppy direct eval, pollute the enclosing scope
// with this new binding by doing the following:
// The proxy is bound to a lookup variable to force a dynamic declaration
// using the DeclareLookupSlot runtime function.
Variable::Kind kind = Variable::NORMAL;
// TODO(sigurds) figure out if kNotAssigned is OK here
var = new (zone()) Variable(declaration_scope, name, mode, kind,
declaration->initialization(), kNotAssigned);
var->AllocateTo(VariableLocation::LOOKUP, -1);
var->SetFromEval();
resolve = true;
}
// We add a declaration node for every declaration. The compiler
// will only generate code if necessary. In particular, declarations
// for inner local variables that do not represent functions won't
// result in any generated code.
//
// Note that we always add an unresolved proxy even if it's not
// used, simply because we don't know in this method (w/o extra
// parameters) if the proxy is needed or not. The proxy will be
// bound during variable resolution time unless it was pre-bound
// below.
//
// WARNING: This will lead to multiple declaration nodes for the
// same variable if it is declared several times. This is not a
// semantic issue as long as we keep the source order, but it may be
// a performance issue since it may lead to repeated
// RuntimeHidden_DeclareLookupSlot calls.
declaration_scope->AddDeclaration(declaration);
// If requested and we have a local variable, bind the proxy to the variable
// at parse-time. This is used for functions (and consts) declared inside
// statements: the corresponding function (or const) variable must be in the
// function scope and not a statement-local scope, e.g. as provided with a
// 'with' statement:
//
// with (obj) {
// function f() {}
// }
//
// which is translated into:
//
// with (obj) {
// // in this case this is not: 'var f; f = function () {};'
// var f = function () {};
// }
//
// Note that if 'f' is accessed from inside the 'with' statement, it
// will be allocated in the context (because we must be able to look
// it up dynamically) but it will also be accessed statically, i.e.,
// with a context slot index and a context chain length for this
// initialization code. Thus, inside the 'with' statement, we need
// both access to the static and the dynamic context chain; the
// runtime needs to provide both.
if (resolve && var != NULL) {
proxy->BindTo(var);
}
return var;
}
// Language extension which is only enabled for source files loaded
// through the API's extension mechanism. A native function
// declaration is resolved by looking up the function through a
// callback provided by the extension.
Statement* Parser::ParseNativeDeclaration(bool* ok) {
int pos = peek_position();
Expect(Token::FUNCTION, CHECK_OK);
// Allow "eval" or "arguments" for backward compatibility.
const AstRawString* name =
ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
bool done = (peek() == Token::RPAREN);
while (!done) {
ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
done = (peek() == Token::RPAREN);
if (!done) {
Expect(Token::COMMA, CHECK_OK);
}
}
Expect(Token::RPAREN, CHECK_OK);
Expect(Token::SEMICOLON, CHECK_OK);
// Make sure that the function containing the native declaration
// isn't lazily compiled. The extension structures are only
// accessible while parsing the first time not when reparsing
// because of lazy compilation.
// TODO(adamk): Should this be ClosureScope()?
scope_->DeclarationScope()->ForceEagerCompilation();
// TODO(1240846): It's weird that native function declarations are
// introduced dynamically when we meet their declarations, whereas
// other functions are set up when entering the surrounding scope.
VariableProxy* proxy = NewUnresolved(name, VAR);
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, VAR, scope_, pos);
Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
NativeFunctionLiteral* lit = factory()->NewNativeFunctionLiteral(
name, extension_, RelocInfo::kNoPosition);
return factory()->NewExpressionStatement(
factory()->NewAssignment(Token::INIT, proxy, lit, RelocInfo::kNoPosition),
pos);
}
Statement* Parser::ParseHoistableDeclaration(
ZoneList<const AstRawString*>* names, bool* ok) {
Expect(Token::FUNCTION, CHECK_OK);
int pos = position();
ParseFunctionFlags flags = ParseFunctionFlags::kIsNormal;
if (Check(Token::MUL)) {
flags |= ParseFunctionFlags::kIsGenerator;
}
return ParseHoistableDeclaration(pos, flags, names, ok);
}
Statement* Parser::ParseAsyncFunctionDeclaration(
ZoneList<const AstRawString*>* names, bool* ok) {
DCHECK_EQ(scanner()->current_token(), Token::ASYNC);
int pos = position();
if (scanner()->HasAnyLineTerminatorBeforeNext()) {
*ok = false;
ReportUnexpectedToken(scanner()->current_token());
return nullptr;
}
Expect(Token::FUNCTION, CHECK_OK);
ParseFunctionFlags flags = ParseFunctionFlags::kIsAsync;
return ParseHoistableDeclaration(pos, flags, names, ok);
}
Statement* Parser::ParseHoistableDeclaration(
int pos, ParseFunctionFlags flags, ZoneList<const AstRawString*>* names,
bool* ok) {
// FunctionDeclaration ::
// 'function' Identifier '(' FormalParameters ')' '{' FunctionBody '}'
// GeneratorDeclaration ::
// 'function' '*' Identifier '(' FormalParameters ')' '{' FunctionBody '}'
//
// 'function' and '*' (if present) have been consumed by the caller.
const bool is_generator = flags & ParseFunctionFlags::kIsGenerator;
const bool is_async = flags & ParseFunctionFlags::kIsAsync;
DCHECK(!is_generator || !is_async);
bool is_strict_reserved = false;
const AstRawString* name = ParseIdentifierOrStrictReservedWord(
&is_strict_reserved, CHECK_OK);
if (V8_UNLIKELY(is_async_function() && this->IsAwait(name))) {
ReportMessageAt(scanner()->location(),
MessageTemplate::kAwaitBindingIdentifier);
*ok = false;
return nullptr;
}
FuncNameInferrer::State fni_state(fni_);
if (fni_ != NULL) fni_->PushEnclosingName(name);
FunctionLiteral* fun = ParseFunctionLiteral(
name, scanner()->location(),
is_strict_reserved ? kFunctionNameIsStrictReserved
: kFunctionNameValidityUnknown,
is_generator ? FunctionKind::kGeneratorFunction
: is_async ? FunctionKind::kAsyncFunction
: FunctionKind::kNormalFunction,
pos, FunctionLiteral::kDeclaration, language_mode(), CHECK_OK);
// Even if we're not at the top-level of the global or a function
// scope, we treat it as such and introduce the function with its
// initial value upon entering the corresponding scope.
// In ES6, a function behaves as a lexical binding, except in
// a script scope, or the initial scope of eval or another function.
VariableMode mode =
(!scope_->is_declaration_scope() || scope_->is_module_scope()) ? LET
: VAR;
VariableProxy* proxy = NewUnresolved(name, mode);
Declaration* declaration =
factory()->NewFunctionDeclaration(proxy, mode, fun, scope_, pos);
Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
if (names) names->Add(name, zone());
EmptyStatement* empty = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
// Async functions don't undergo sloppy mode block scoped hoisting, and don't
// allow duplicates in a block. Both are represented by the
// sloppy_block_function_map. Don't add them to the map for async functions.
// Generators are also supposed to be prohibited; currently doing this behind
// a flag and UseCounting violations to assess web compatibility.
if (is_sloppy(language_mode()) && !scope_->is_declaration_scope() &&
!is_async && !(allow_harmony_restrictive_generators() && is_generator)) {
SloppyBlockFunctionStatement* delegate =
factory()->NewSloppyBlockFunctionStatement(empty, scope_);
scope_->DeclarationScope()->sloppy_block_function_map()->Declare(name,
delegate);
return delegate;
}
return empty;
}
Statement* Parser::ParseClassDeclaration(ZoneList<const AstRawString*>* names,
bool* ok) {
// ClassDeclaration ::
// 'class' Identifier ('extends' LeftHandExpression)? '{' ClassBody '}'
//
// 'class' is expected to be consumed by the caller.
//
// A ClassDeclaration
//
// class C { ... }
//
// has the same semantics as:
//
// let C = class C { ... };
//
// so rewrite it as such.
int pos = position();
bool is_strict_reserved = false;
const AstRawString* name =
ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
ClassLiteral* value = ParseClassLiteral(nullptr, name, scanner()->location(),
is_strict_reserved, pos, CHECK_OK);
VariableProxy* proxy = NewUnresolved(name, LET);
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, LET, scope_, pos);
Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
proxy->var()->set_initializer_position(position());
Assignment* assignment =
factory()->NewAssignment(Token::INIT, proxy, value, pos);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition);
if (names) names->Add(name, zone());
return assignment_statement;
}
Block* Parser::ParseBlock(ZoneList<const AstRawString*>* labels,
bool finalize_block_scope, bool* ok) {
// The harmony mode uses block elements instead of statements.
//
// Block ::
// '{' StatementList '}'
// Construct block expecting 16 statements.
Block* body =
factory()->NewBlock(labels, 16, false, RelocInfo::kNoPosition);
Scope* block_scope = NewScope(scope_, BLOCK_SCOPE);
// Parse the statements and collect escaping labels.
Expect(Token::LBRACE, CHECK_OK);
block_scope->set_start_position(scanner()->location().beg_pos);
{ BlockState block_state(&scope_, block_scope);
Target target(&this->target_stack_, body);
while (peek() != Token::RBRACE) {
Statement* stat = ParseStatementListItem(CHECK_OK);
if (stat && !stat->IsEmpty()) {
body->statements()->Add(stat, zone());
}
}
}
Expect(Token::RBRACE, CHECK_OK);
block_scope->set_end_position(scanner()->location().end_pos);
if (finalize_block_scope) {
block_scope = block_scope->FinalizeBlockScope();
}
body->set_scope(block_scope);
return body;
}
Block* Parser::ParseBlock(ZoneList<const AstRawString*>* labels, bool* ok) {
return ParseBlock(labels, true, ok);
}
Block* Parser::DeclarationParsingResult::BuildInitializationBlock(
ZoneList<const AstRawString*>* names, bool* ok) {
Block* result = descriptor.parser->factory()->NewBlock(
NULL, 1, true, descriptor.declaration_pos);
for (auto declaration : declarations) {
PatternRewriter::DeclareAndInitializeVariables(
result, &descriptor, &declaration, names, CHECK_OK);
}
return result;
}
Block* Parser::ParseVariableStatement(VariableDeclarationContext var_context,
ZoneList<const AstRawString*>* names,
bool* ok) {
// VariableStatement ::
// VariableDeclarations ';'
// The scope of a var/const declared variable anywhere inside a function
// is the entire function (ECMA-262, 3rd, 10.1.3, and 12.2). Thus we can
// transform a source-level var/const declaration into a (Function)
// Scope declaration, and rewrite the source-level initialization into an
// assignment statement. We use a block to collect multiple assignments.
//
// We mark the block as initializer block because we don't want the
// rewriter to add a '.result' assignment to such a block (to get compliant
// behavior for code such as print(eval('var x = 7')), and for cosmetic
// reasons when pretty-printing. Also, unless an assignment (initialization)
// is inside an initializer block, it is ignored.
DeclarationParsingResult parsing_result;
Block* result =
ParseVariableDeclarations(var_context, &parsing_result, names, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return result;
}
Block* Parser::ParseVariableDeclarations(
VariableDeclarationContext var_context,
DeclarationParsingResult* parsing_result,
ZoneList<const AstRawString*>* names, bool* ok) {
// VariableDeclarations ::
// ('var' | 'const' | 'let') (Identifier ('=' AssignmentExpression)?)+[',']
//
// The ES6 Draft Rev3 specifies the following grammar for const declarations
//
// ConstDeclaration ::
// const ConstBinding (',' ConstBinding)* ';'
// ConstBinding ::
// Identifier '=' AssignmentExpression
//
// TODO(ES6):
// ConstBinding ::
// BindingPattern '=' AssignmentExpression
parsing_result->descriptor.parser = this;
parsing_result->descriptor.declaration_kind = DeclarationDescriptor::NORMAL;
parsing_result->descriptor.declaration_pos = peek_position();
parsing_result->descriptor.initialization_pos = peek_position();
parsing_result->descriptor.mode = VAR;
Block* init_block = nullptr;
if (var_context != kForStatement) {
init_block = factory()->NewBlock(
NULL, 1, true, parsing_result->descriptor.declaration_pos);
}
if (peek() == Token::VAR) {
Consume(Token::VAR);
} else if (peek() == Token::CONST) {
Consume(Token::CONST);
DCHECK(var_context != kStatement);
parsing_result->descriptor.mode = CONST;
} else if (peek() == Token::LET) {
Consume(Token::LET);
DCHECK(var_context != kStatement);
parsing_result->descriptor.mode = LET;
} else {
UNREACHABLE(); // by current callers
}
parsing_result->descriptor.scope = scope_;
parsing_result->descriptor.hoist_scope = nullptr;
bool first_declaration = true;
int bindings_start = peek_position();
do {
FuncNameInferrer::State fni_state(fni_);
// Parse name.
if (!first_declaration) Consume(Token::COMMA);
Expression* pattern;
int decl_pos = peek_position();
{
ExpressionClassifier pattern_classifier(this);
pattern = ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
ValidateBindingPattern(&pattern_classifier, CHECK_OK);
if (IsLexicalVariableMode(parsing_result->descriptor.mode)) {
ValidateLetPattern(&pattern_classifier, CHECK_OK);
}
}
Scanner::Location variable_loc = scanner()->location();
const AstRawString* single_name =
pattern->IsVariableProxy() ? pattern->AsVariableProxy()->raw_name()
: nullptr;
if (single_name != nullptr) {
if (fni_ != NULL) fni_->PushVariableName(single_name);
}
Expression* value = NULL;
int initializer_position = RelocInfo::kNoPosition;
if (Check(Token::ASSIGN)) {
ExpressionClassifier classifier(this);
value = ParseAssignmentExpression(var_context != kForStatement,
&classifier, CHECK_OK);
RewriteNonPattern(&classifier, CHECK_OK);
variable_loc.end_pos = scanner()->location().end_pos;
if (!parsing_result->first_initializer_loc.IsValid()) {
parsing_result->first_initializer_loc = variable_loc;
}
// Don't infer if it is "a = function(){...}();"-like expression.
if (single_name) {
if (fni_ != NULL && value->AsCall() == NULL &&
value->AsCallNew() == NULL) {
fni_->Infer();
} else {
fni_->RemoveLastFunction();
}
}
if (allow_harmony_function_name()) {
ParserTraits::SetFunctionNameFromIdentifierRef(value, pattern);
}
// End position of the initializer is after the assignment expression.
initializer_position = scanner()->location().end_pos;
} else {
// Initializers may be either required or implied unless this is a
// for-in/of iteration variable.
if (var_context != kForStatement || !PeekInOrOf()) {
// ES6 'const' and binding patterns require initializers.
if (parsing_result->descriptor.mode == CONST ||
!pattern->IsVariableProxy()) {
ParserTraits::ReportMessageAt(
Scanner::Location(decl_pos, scanner()->location().end_pos),
MessageTemplate::kDeclarationMissingInitializer,
!pattern->IsVariableProxy() ? "destructuring" : "const");
*ok = false;
return nullptr;
}
// 'let x' initializes 'x' to undefined.
if (parsing_result->descriptor.mode == LET) {
value = GetLiteralUndefined(position());
}
}
// End position of the initializer is after the variable.
initializer_position = position();
}
DeclarationParsingResult::Declaration decl(pattern, initializer_position,
value);
if (var_context == kForStatement) {
// Save the declaration for further handling in ParseForStatement.
parsing_result->declarations.Add(decl);
} else {
// Immediately declare the variable otherwise. This avoids O(N^2)
// behavior (where N is the number of variables in a single
// declaration) in the PatternRewriter having to do with removing
// and adding VariableProxies to the Scope (see bug 4699).
DCHECK_NOT_NULL(init_block);
PatternRewriter::DeclareAndInitializeVariables(
init_block, &parsing_result->descriptor, &decl, names, CHECK_OK);
}
first_declaration = false;
} while (peek() == Token::COMMA);
parsing_result->bindings_loc =
Scanner::Location(bindings_start, scanner()->location().end_pos);
DCHECK(*ok);
return init_block;
}
static bool ContainsLabel(ZoneList<const AstRawString*>* labels,
const AstRawString* label) {
DCHECK(label != NULL);
if (labels != NULL) {
for (int i = labels->length(); i-- > 0; ) {
if (labels->at(i) == label) {
return true;
}
}
}
return false;
}
Statement* Parser::ParseFunctionDeclaration(bool* ok) {
Consume(Token::FUNCTION);
int pos = position();
ParseFunctionFlags flags = ParseFunctionFlags::kIsNormal;
if (Check(Token::MUL)) {
flags |= ParseFunctionFlags::kIsGenerator;
if (allow_harmony_restrictive_declarations()) {
ParserTraits::ReportMessageAt(scanner()->location(),
MessageTemplate::kGeneratorInLegacyContext);
*ok = false;
return nullptr;
}
}
return ParseHoistableDeclaration(pos, flags, nullptr, CHECK_OK);
}
Statement* Parser::ParseExpressionOrLabelledStatement(
ZoneList<const AstRawString*>* labels,
AllowLabelledFunctionStatement allow_function, bool* ok) {
// ExpressionStatement | LabelledStatement ::
// Expression ';'
// Identifier ':' Statement
//
// ExpressionStatement[Yield] :
// [lookahead ∉ {{, function, class, let [}] Expression[In, ?Yield] ;
int pos = peek_position();
switch (peek()) {
case Token::FUNCTION:
case Token::LBRACE:
UNREACHABLE(); // Always handled by the callers.
case Token::CLASS:
ReportUnexpectedToken(Next());
*ok = false;
return nullptr;
default:
break;
}
bool starts_with_idenfifier = peek_any_identifier();
Expression* expr = ParseExpression(true, CHECK_OK);
if (peek() == Token::COLON && starts_with_idenfifier && expr != NULL &&
expr->AsVariableProxy() != NULL &&
!expr->AsVariableProxy()->is_this()) {
// Expression is a single identifier, and not, e.g., a parenthesized
// identifier.
VariableProxy* var = expr->AsVariableProxy();
const AstRawString* label = var->raw_name();
// TODO(1240780): We don't check for redeclaration of labels
// during preparsing since keeping track of the set of active
// labels requires nontrivial changes to the way scopes are
// structured. However, these are probably changes we want to
// make later anyway so we should go back and fix this then.
if (ContainsLabel(labels, label) || TargetStackContainsLabel(label)) {
ParserTraits::ReportMessage(MessageTemplate::kLabelRedeclaration, label);
*ok = false;
return NULL;
}
if (labels == NULL) {
labels = new(zone()) ZoneList<const AstRawString*>(4, zone());
}
labels->Add(label, zone());
// Remove the "ghost" variable that turned out to be a label
// from the top scope. This way, we don't try to resolve it
// during the scope processing.
scope_->RemoveUnresolved(var);
Expect(Token::COLON, CHECK_OK);
// ES#sec-labelled-function-declarations Labelled Function Declarations
if (peek() == Token::FUNCTION && is_sloppy(language_mode())) {
if (allow_function == kAllowLabelledFunctionStatement) {
return ParseFunctionDeclaration(ok);
} else {
return ParseScopedStatement(labels, true, ok);
}
}
return ParseStatement(labels, kDisallowLabelledFunctionStatement, ok);
}
// If we have an extension, we allow a native function declaration.
// A native function declaration starts with "native function" with
// no line-terminator between the two words.
if (extension_ != NULL && peek() == Token::FUNCTION &&
!scanner()->HasAnyLineTerminatorBeforeNext() && expr != NULL &&
expr->AsVariableProxy() != NULL &&
expr->AsVariableProxy()->raw_name() ==
ast_value_factory()->native_string() &&
!scanner()->literal_contains_escapes()) {
return ParseNativeDeclaration(ok);
}
// Parsed expression statement, followed by semicolon.
ExpectSemicolon(CHECK_OK);
return factory()->NewExpressionStatement(expr, pos);
}
IfStatement* Parser::ParseIfStatement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// IfStatement ::
// 'if' '(' Expression ')' Statement ('else' Statement)?
int pos = peek_position();
Expect(Token::IF, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* condition = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* then_statement = ParseScopedStatement(labels, false, CHECK_OK);
Statement* else_statement = NULL;
if (peek() == Token::ELSE) {
Next();
else_statement = ParseScopedStatement(labels, false, CHECK_OK);
} else {
else_statement = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
}
return factory()->NewIfStatement(
condition, then_statement, else_statement, pos);
}
Statement* Parser::ParseContinueStatement(bool* ok) {
// ContinueStatement ::
// 'continue' Identifier? ';'
int pos = peek_position();
Expect(Token::CONTINUE, CHECK_OK);
const AstRawString* label = NULL;
Token::Value tok = peek();
if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
tok != Token::SEMICOLON && tok != Token::RBRACE && tok != Token::EOS) {
// ECMA allows "eval" or "arguments" as labels even in strict mode.
label = ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
}
IterationStatement* target = LookupContinueTarget(label, CHECK_OK);
if (target == NULL) {
// Illegal continue statement.
MessageTemplate::Template message = MessageTemplate::kIllegalContinue;
if (label != NULL) {
message = MessageTemplate::kUnknownLabel;
}
ParserTraits::ReportMessage(message, label);
*ok = false;
return NULL;
}
ExpectSemicolon(CHECK_OK);
return factory()->NewContinueStatement(target, pos);
}
Statement* Parser::ParseBreakStatement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// BreakStatement ::
// 'break' Identifier? ';'
int pos = peek_position();
Expect(Token::BREAK, CHECK_OK);
const AstRawString* label = NULL;
Token::Value tok = peek();
if (!scanner()->HasAnyLineTerminatorBeforeNext() &&
tok != Token::SEMICOLON && tok != Token::RBRACE && tok != Token::EOS) {
// ECMA allows "eval" or "arguments" as labels even in strict mode.
label = ParseIdentifier(kAllowRestrictedIdentifiers, CHECK_OK);
}
// Parse labeled break statements that target themselves into
// empty statements, e.g. 'l1: l2: l3: break l2;'
if (label != NULL && ContainsLabel(labels, label)) {
ExpectSemicolon(CHECK_OK);
return factory()->NewEmptyStatement(pos);
}
BreakableStatement* target = NULL;
target = LookupBreakTarget(label, CHECK_OK);
if (target == NULL) {
// Illegal break statement.
MessageTemplate::Template message = MessageTemplate::kIllegalBreak;
if (label != NULL) {
message = MessageTemplate::kUnknownLabel;
}
ParserTraits::ReportMessage(message, label);
*ok = false;
return NULL;
}
ExpectSemicolon(CHECK_OK);
return factory()->NewBreakStatement(target, pos);
}
Statement* Parser::ParseReturnStatement(bool* ok) {
// ReturnStatement ::
// 'return' Expression? ';'
// Consume the return token. It is necessary to do that before
// reporting any errors on it, because of the way errors are
// reported (underlining).
Expect(Token::RETURN, CHECK_OK);
Scanner::Location loc = scanner()->location();
function_state_->set_return_location(loc);
Token::Value tok = peek();
Statement* result;
Expression* return_value;
if (scanner()->HasAnyLineTerminatorBeforeNext() ||
tok == Token::SEMICOLON ||
tok == Token::RBRACE ||
tok == Token::EOS) {
if (IsSubclassConstructor(function_state_->kind())) {
return_value = ThisExpression(scope_, factory(), loc.beg_pos);
} else {
return_value = GetLiteralUndefined(position());
}
} else {
int pos = peek_position();
if (IsSubclassConstructor(function_state_->kind())) {
// Because of the return code rewriting that happens in case of a subclass
// constructor we don't want to accept tail calls, therefore we don't set
// ReturnExprScope to kInsideValidReturnStatement here.
return_value = ParseExpression(true, CHECK_OK);
// For subclass constructors we need to return this in case of undefined
// return a Smi (transformed into an exception in the ConstructStub)
// for a non object.
//
// return expr;
//
// Is rewritten as:
//
// return (temp = expr) === undefined ? this :
// %_IsJSReceiver(temp) ? temp : 1;
// temp = expr
Variable* temp = scope_->NewTemporary(
ast_value_factory()->empty_string());
Assignment* assign = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(temp), return_value, pos);
// %_IsJSReceiver(temp)
ZoneList<Expression*>* is_spec_object_args =
new (zone()) ZoneList<Expression*>(1, zone());
is_spec_object_args->Add(factory()->NewVariableProxy(temp), zone());
Expression* is_spec_object_call = factory()->NewCallRuntime(
Runtime::kInlineIsJSReceiver, is_spec_object_args, pos);
// %_IsJSReceiver(temp) ? temp : 1;
Expression* is_object_conditional = factory()->NewConditional(
is_spec_object_call, factory()->NewVariableProxy(temp),
factory()->NewSmiLiteral(1, pos), pos);
// temp === undefined
Expression* is_undefined = factory()->NewCompareOperation(
Token::EQ_STRICT, assign,
factory()->NewUndefinedLiteral(RelocInfo::kNoPosition), pos);
// is_undefined ? this : is_object_conditional
return_value = factory()->NewConditional(
is_undefined, ThisExpression(scope_, factory(), pos),
is_object_conditional, pos);
} else {
ReturnExprScope maybe_allow_tail_calls(
function_state_, ReturnExprContext::kInsideValidReturnStatement);
return_value = ParseExpression(true, CHECK_OK);
if (allow_tailcalls() && !is_sloppy(language_mode())) {
// ES6 14.6.1 Static Semantics: IsInTailPosition
function_state_->AddImplicitTailCallExpression(return_value);
}
}
}
ExpectSemicolon(CHECK_OK);
if (is_generator()) {
return_value = BuildIteratorResult(return_value, true);
} else if (is_async_function()) {
return_value = BuildPromiseResolve(return_value, return_value->position());
}
result = factory()->NewReturnStatement(return_value, loc.beg_pos);
Scope* decl_scope = scope_->DeclarationScope();
if (decl_scope->is_script_scope() || decl_scope->is_eval_scope()) {
ReportMessageAt(loc, MessageTemplate::kIllegalReturn);
*ok = false;
return NULL;
}
return result;
}
Statement* Parser::ParseWithStatement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// WithStatement ::
// 'with' '(' Expression ')' Statement
Expect(Token::WITH, CHECK_OK);
int pos = position();
if (is_strict(language_mode())) {
ReportMessage(MessageTemplate::kStrictWith);
*ok = false;
return NULL;
}
Expect(Token::LPAREN, CHECK_OK);
Expression* expr = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Scope* with_scope = NewScope(scope_, WITH_SCOPE);
Statement* body;
{ BlockState block_state(&scope_, with_scope);
with_scope->set_start_position(scanner()->peek_location().beg_pos);
body = ParseScopedStatement(labels, true, CHECK_OK);
with_scope->set_end_position(scanner()->location().end_pos);
}
return factory()->NewWithStatement(with_scope, expr, body, pos);
}
CaseClause* Parser::ParseCaseClause(bool* default_seen_ptr, bool* ok) {
// CaseClause ::
// 'case' Expression ':' StatementList
// 'default' ':' StatementList
Expression* label = NULL; // NULL expression indicates default case
if (peek() == Token::CASE) {
Expect(Token::CASE, CHECK_OK);
label = ParseExpression(true, CHECK_OK);
} else {
Expect(Token::DEFAULT, CHECK_OK);
if (*default_seen_ptr) {
ReportMessage(MessageTemplate::kMultipleDefaultsInSwitch);
*ok = false;
return NULL;
}
*default_seen_ptr = true;
}
Expect(Token::COLON, CHECK_OK);
int pos = position();
ZoneList<Statement*>* statements =
new(zone()) ZoneList<Statement*>(5, zone());
Statement* stat = NULL;
while (peek() != Token::CASE &&
peek() != Token::DEFAULT &&
peek() != Token::RBRACE) {
stat = ParseStatementListItem(CHECK_OK);
statements->Add(stat, zone());
}
return factory()->NewCaseClause(label, statements, pos);
}
Statement* Parser::ParseSwitchStatement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// SwitchStatement ::
// 'switch' '(' Expression ')' '{' CaseClause* '}'
// In order to get the CaseClauses to execute in their own lexical scope,
// but without requiring downstream code to have special scope handling
// code for switch statements, desugar into blocks as follows:
// { // To group the statements--harmless to evaluate Expression in scope
// .tag_variable = Expression;
// { // To give CaseClauses a scope
// switch (.tag_variable) { CaseClause* }
// }
// }
Block* switch_block =
factory()->NewBlock(NULL, 2, false, RelocInfo::kNoPosition);
int switch_pos = peek_position();
Expect(Token::SWITCH, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* tag = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Variable* tag_variable =
scope_->NewTemporary(ast_value_factory()->dot_switch_tag_string());
Assignment* tag_assign = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(tag_variable), tag,
tag->position());
Statement* tag_statement =
factory()->NewExpressionStatement(tag_assign, RelocInfo::kNoPosition);
switch_block->statements()->Add(tag_statement, zone());
// make statement: undefined;
// This is needed so the tag isn't returned as the value, in case the switch
// statements don't have a value.
switch_block->statements()->Add(
factory()->NewExpressionStatement(
factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
zone());
Block* cases_block =
factory()->NewBlock(NULL, 1, false, RelocInfo::kNoPosition);
Scope* cases_scope = NewScope(scope_, BLOCK_SCOPE);
cases_scope->SetNonlinear();
SwitchStatement* switch_statement =
factory()->NewSwitchStatement(labels, switch_pos);
cases_scope->set_start_position(scanner()->location().beg_pos);
{
BlockState cases_block_state(&scope_, cases_scope);
Target target(&this->target_stack_, switch_statement);
Expression* tag_read = factory()->NewVariableProxy(tag_variable);
bool default_seen = false;
ZoneList<CaseClause*>* cases =
new (zone()) ZoneList<CaseClause*>(4, zone());
Expect(Token::LBRACE, CHECK_OK);
while (peek() != Token::RBRACE) {
CaseClause* clause = ParseCaseClause(&default_seen, CHECK_OK);
cases->Add(clause, zone());
}
switch_statement->Initialize(tag_read, cases);
cases_block->statements()->Add(switch_statement, zone());
}
Expect(Token::RBRACE, CHECK_OK);
cases_scope->set_end_position(scanner()->location().end_pos);
cases_scope = cases_scope->FinalizeBlockScope();
cases_block->set_scope(cases_scope);
switch_block->statements()->Add(cases_block, zone());
return switch_block;
}
Statement* Parser::ParseThrowStatement(bool* ok) {
// ThrowStatement ::
// 'throw' Expression ';'
Expect(Token::THROW, CHECK_OK);
int pos = position();
if (scanner()->HasAnyLineTerminatorBeforeNext()) {
ReportMessage(MessageTemplate::kNewlineAfterThrow);
*ok = false;
return NULL;
}
Expression* exception = ParseExpression(true, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return factory()->NewExpressionStatement(
factory()->NewThrow(exception, pos), pos);
}
TryStatement* Parser::ParseTryStatement(bool* ok) {
// TryStatement ::
// 'try' Block Catch
// 'try' Block Finally
// 'try' Block Catch Finally
//
// Catch ::
// 'catch' '(' Identifier ')' Block
//
// Finally ::
// 'finally' Block
Expect(Token::TRY, CHECK_OK);
int pos = position();
Block* try_block;
{
ReturnExprScope no_tail_calls(function_state_,
ReturnExprContext::kInsideTryBlock);
try_block = ParseBlock(NULL, CHECK_OK);
}
Token::Value tok = peek();
if (tok != Token::CATCH && tok != Token::FINALLY) {
ReportMessage(MessageTemplate::kNoCatchOrFinally);
*ok = false;
return NULL;
}
Scope* catch_scope = NULL;
Variable* catch_variable = NULL;
Block* catch_block = NULL;
TailCallExpressionList tail_call_expressions_in_catch_block(zone());
if (tok == Token::CATCH) {
Consume(Token::CATCH);
Expect(Token::LPAREN, CHECK_OK);
catch_scope = NewScope(scope_, CATCH_SCOPE);
catch_scope->set_start_position(scanner()->location().beg_pos);
ExpressionClassifier pattern_classifier(this);
Expression* pattern = ParsePrimaryExpression(&pattern_classifier, CHECK_OK);
ValidateBindingPattern(&pattern_classifier, CHECK_OK);
const AstRawString* name = ast_value_factory()->dot_catch_string();
bool is_simple = pattern->IsVariableProxy();
if (is_simple) {
auto proxy = pattern->AsVariableProxy();
scope_->RemoveUnresolved(proxy);
name = proxy->raw_name();
}
catch_variable = catch_scope->DeclareLocal(name, VAR, kCreatedInitialized,
Variable::NORMAL);
Expect(Token::RPAREN, CHECK_OK);
{
CollectExpressionsInTailPositionToListScope
collect_tail_call_expressions_scope(
function_state_, &tail_call_expressions_in_catch_block);
BlockState block_state(&scope_, catch_scope);
// TODO(adamk): Make a version of ParseBlock that takes a scope and
// a block.
catch_block =
factory()->NewBlock(nullptr, 16, false, RelocInfo::kNoPosition);
Scope* block_scope = NewScope(scope_, BLOCK_SCOPE);
block_scope->set_start_position(scanner()->location().beg_pos);
{
BlockState block_state(&scope_, block_scope);
Target target(&this->target_stack_, catch_block);
if (!is_simple) {
DeclarationDescriptor descriptor;
descriptor.declaration_kind = DeclarationDescriptor::NORMAL;
descriptor.parser = this;
descriptor.scope = scope_;
descriptor.hoist_scope = nullptr;
descriptor.mode = LET;
descriptor.declaration_pos = pattern->position();
descriptor.initialization_pos = pattern->position();
DeclarationParsingResult::Declaration decl(
pattern, pattern->position(),
factory()->NewVariableProxy(catch_variable));
Block* init_block =
factory()->NewBlock(nullptr, 8, true, RelocInfo::kNoPosition);
PatternRewriter::DeclareAndInitializeVariables(
init_block, &descriptor, &decl, nullptr, CHECK_OK);
catch_block->statements()->Add(init_block, zone());
}
Expect(Token::LBRACE, CHECK_OK);
while (peek() != Token::RBRACE) {
Statement* stat = ParseStatementListItem(CHECK_OK);
if (stat && !stat->IsEmpty()) {
catch_block->statements()->Add(stat, zone());
}
}
Consume(Token::RBRACE);
}
block_scope->set_end_position(scanner()->location().end_pos);
block_scope = block_scope->FinalizeBlockScope();
catch_block->set_scope(block_scope);
}
catch_scope->set_end_position(scanner()->location().end_pos);
tok = peek();
}
Block* finally_block = NULL;
DCHECK(tok == Token::FINALLY || catch_block != NULL);
if (tok == Token::FINALLY) {
Consume(Token::FINALLY);
finally_block = ParseBlock(NULL, CHECK_OK);
}
// Simplify the AST nodes by converting:
// 'try B0 catch B1 finally B2'
// to:
// 'try { try B0 catch B1 } finally B2'
if (catch_block != NULL && finally_block != NULL) {
// If we have both, create an inner try/catch.
DCHECK(catch_scope != NULL && catch_variable != NULL);
TryCatchStatement* statement =
factory()->NewTryCatchStatement(try_block, catch_scope, catch_variable,
catch_block, RelocInfo::kNoPosition);
try_block = factory()->NewBlock(NULL, 1, false, RelocInfo::kNoPosition);
try_block->statements()->Add(statement, zone());
catch_block = NULL; // Clear to indicate it's been handled.
}
TryStatement* result = NULL;
if (catch_block != NULL) {
// For a try-catch construct append return expressions from the catch block
// to the list of return expressions.
function_state_->tail_call_expressions().Append(
tail_call_expressions_in_catch_block);
DCHECK(finally_block == NULL);
DCHECK(catch_scope != NULL && catch_variable != NULL);
result = factory()->NewTryCatchStatement(try_block, catch_scope,
catch_variable, catch_block, pos);
} else {
if (FLAG_harmony_explicit_tailcalls &&
tail_call_expressions_in_catch_block.has_explicit_tail_calls()) {
// TODO(ishell): update chapter number.
// ES8 XX.YY.ZZ
ReportMessageAt(tail_call_expressions_in_catch_block.location(),
MessageTemplate::kUnexpectedTailCallInCatchBlock);
*ok = false;
return NULL;
}
DCHECK(finally_block != NULL);
result = factory()->NewTryFinallyStatement(try_block, finally_block, pos);
}
return result;
}
DoWhileStatement* Parser::ParseDoWhileStatement(
ZoneList<const AstRawString*>* labels, bool* ok) {
// DoStatement ::
// 'do' Statement 'while' '(' Expression ')' ';'
DoWhileStatement* loop =
factory()->NewDoWhileStatement(labels, peek_position());
Target target(&this->target_stack_, loop);
Expect(Token::DO, CHECK_OK);
Statement* body = ParseScopedStatement(NULL, true, CHECK_OK);
Expect(Token::WHILE, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* cond = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
// Allow do-statements to be terminated with and without
// semi-colons. This allows code such as 'do;while(0)return' to
// parse, which would not be the case if we had used the
// ExpectSemicolon() functionality here.
if (peek() == Token::SEMICOLON) Consume(Token::SEMICOLON);
if (loop != NULL) loop->Initialize(cond, body);
return loop;
}
WhileStatement* Parser::ParseWhileStatement(
ZoneList<const AstRawString*>* labels, bool* ok) {
// WhileStatement ::
// 'while' '(' Expression ')' Statement
WhileStatement* loop = factory()->NewWhileStatement(labels, peek_position());
Target target(&this->target_stack_, loop);
Expect(Token::WHILE, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* cond = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseScopedStatement(NULL, true, CHECK_OK);
if (loop != NULL) loop->Initialize(cond, body);
return loop;
}
// !%_IsJSReceiver(result = iterator.next()) &&
// %ThrowIteratorResultNotAnObject(result)
Expression* Parser::BuildIteratorNextResult(Expression* iterator,
Variable* result, int pos) {
Expression* next_literal = factory()->NewStringLiteral(
ast_value_factory()->next_string(), RelocInfo::kNoPosition);
Expression* next_property =
factory()->NewProperty(iterator, next_literal, RelocInfo::kNoPosition);
ZoneList<Expression*>* next_arguments =
new (zone()) ZoneList<Expression*>(0, zone());
Expression* next_call =
factory()->NewCall(next_property, next_arguments, pos);
Expression* result_proxy = factory()->NewVariableProxy(result);
Expression* left =
factory()->NewAssignment(Token::ASSIGN, result_proxy, next_call, pos);
// %_IsJSReceiver(...)
ZoneList<Expression*>* is_spec_object_args =
new (zone()) ZoneList<Expression*>(1, zone());
is_spec_object_args->Add(left, zone());
Expression* is_spec_object_call = factory()->NewCallRuntime(
Runtime::kInlineIsJSReceiver, is_spec_object_args, pos);
// %ThrowIteratorResultNotAnObject(result)
Expression* result_proxy_again = factory()->NewVariableProxy(result);
ZoneList<Expression*>* throw_arguments =
new (zone()) ZoneList<Expression*>(1, zone());
throw_arguments->Add(result_proxy_again, zone());
Expression* throw_call = factory()->NewCallRuntime(
Runtime::kThrowIteratorResultNotAnObject, throw_arguments, pos);
return factory()->NewBinaryOperation(
Token::AND,
factory()->NewUnaryOperation(Token::NOT, is_spec_object_call, pos),
throw_call, pos);
}
void Parser::InitializeForEachStatement(ForEachStatement* stmt,
Expression* each, Expression* subject,
Statement* body, int each_keyword_pos) {
ForOfStatement* for_of = stmt->AsForOfStatement();
if (for_of != NULL) {
InitializeForOfStatement(for_of, each, subject, body, each_keyword_pos);
} else {
if (each->IsArrayLiteral() || each->IsObjectLiteral()) {
Variable* temp =
scope_->NewTemporary(ast_value_factory()->empty_string());
VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);
Expression* assign_each = PatternRewriter::RewriteDestructuringAssignment(
this, factory()->NewAssignment(Token::ASSIGN, each, temp_proxy,
RelocInfo::kNoPosition),
scope_);
auto block =
factory()->NewBlock(nullptr, 2, false, RelocInfo::kNoPosition);
block->statements()->Add(factory()->NewExpressionStatement(
assign_each, RelocInfo::kNoPosition),
zone());
block->statements()->Add(body, zone());
body = block;
each = factory()->NewVariableProxy(temp);
}
stmt->AsForInStatement()->Initialize(each, subject, body);
}
}
void Parser::InitializeForOfStatement(ForOfStatement* for_of, Expression* each,
Expression* iterable, Statement* body,
int next_result_pos) {
Variable* iterator =
scope_->NewTemporary(ast_value_factory()->dot_iterator_string());
Variable* result =
scope_->NewTemporary(ast_value_factory()->dot_result_string());
Expression* assign_iterator;
Expression* next_result;
Expression* result_done;
Expression* assign_each;
int get_iterator_pos = iterable->position();
// iterator = iterable[Symbol.iterator]()
assign_iterator = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(iterator),
GetIterator(iterable, factory(), get_iterator_pos), iterable->position());
// !%_IsJSReceiver(result = iterator.next()) &&
// %ThrowIteratorResultNotAnObject(result)
{
// result = iterator.next()
Expression* iterator_proxy = factory()->NewVariableProxy(iterator);
next_result =
BuildIteratorNextResult(iterator_proxy, result, next_result_pos);
}
// result.done
{
Expression* done_literal = factory()->NewStringLiteral(
ast_value_factory()->done_string(), RelocInfo::kNoPosition);
Expression* result_proxy = factory()->NewVariableProxy(result);
result_done = factory()->NewProperty(result_proxy, done_literal,
RelocInfo::kNoPosition);
}
// each = result.value
{
Expression* value_literal = factory()->NewStringLiteral(
ast_value_factory()->value_string(), RelocInfo::kNoPosition);
Expression* result_proxy = factory()->NewVariableProxy(result);
Expression* result_value = factory()->NewProperty(
result_proxy, value_literal, RelocInfo::kNoPosition);
assign_each = factory()->NewAssignment(Token::ASSIGN, each, result_value,
RelocInfo::kNoPosition);
if (each->IsArrayLiteral() || each->IsObjectLiteral()) {
assign_each = PatternRewriter::RewriteDestructuringAssignment(
this, assign_each->AsAssignment(), scope_);
}
}
for_of->Initialize(body, iterator, assign_iterator, next_result, result_done,
assign_each);
}
Statement* Parser::DesugarLexicalBindingsInForStatement(
Scope* inner_scope, VariableMode mode, ZoneList<const AstRawString*>* names,
ForStatement* loop, Statement* init, Expression* cond, Statement* next,
Statement* body, bool* ok) {
// ES6 13.7.4.8 specifies that on each loop iteration the let variables are
// copied into a new environment. Moreover, the "next" statement must be
// evaluated not in the environment of the just completed iteration but in
// that of the upcoming one. We achieve this with the following desugaring.
// Extra care is needed to preserve the completion value of the original loop.
//
// We are given a for statement of the form
//
// labels: for (let/const x = i; cond; next) body
//
// and rewrite it as follows. Here we write {{ ... }} for init-blocks, ie.,
// blocks whose ignore_completion_value_ flag is set.
//
// {
// let/const x = i;
// temp_x = x;
// first = 1;
// undefined;
// outer: for (;;) {
// let/const x = temp_x;
// {{ if (first == 1) {
// first = 0;
// } else {
// next;
// }
// flag = 1;
// if (!cond) break;
// }}
// labels: for (; flag == 1; flag = 0, temp_x = x) {
// body
// }
// {{ if (flag == 1) // Body used break.
// break;
// }}
// }
// }
DCHECK(names->length() > 0);
ZoneList<Variable*> temps(names->length(), zone());
Block* outer_block = factory()->NewBlock(NULL, names->length() + 4, false,
RelocInfo::kNoPosition);
// Add statement: let/const x = i.
outer_block->statements()->Add(init, zone());
const AstRawString* temp_name = ast_value_factory()->dot_for_string();
// For each lexical variable x:
// make statement: temp_x = x.
for (int i = 0; i < names->length(); i++) {
VariableProxy* proxy = NewUnresolved(names->at(i), LET);
Variable* temp = scope_->NewTemporary(temp_name);
VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, temp_proxy, proxy, RelocInfo::kNoPosition);
Statement* assignment_statement = factory()->NewExpressionStatement(
assignment, RelocInfo::kNoPosition);
outer_block->statements()->Add(assignment_statement, zone());
temps.Add(temp, zone());
}
Variable* first = NULL;
// Make statement: first = 1.
if (next) {
first = scope_->NewTemporary(temp_name);
VariableProxy* first_proxy = factory()->NewVariableProxy(first);
Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, first_proxy, const1, RelocInfo::kNoPosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition);
outer_block->statements()->Add(assignment_statement, zone());
}
// make statement: undefined;
outer_block->statements()->Add(
factory()->NewExpressionStatement(
factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
zone());
// Make statement: outer: for (;;)
// Note that we don't actually create the label, or set this loop up as an
// explicit break target, instead handing it directly to those nodes that
// need to know about it. This should be safe because we don't run any code
// in this function that looks up break targets.
ForStatement* outer_loop =
factory()->NewForStatement(NULL, RelocInfo::kNoPosition);
outer_block->statements()->Add(outer_loop, zone());
outer_block->set_scope(scope_);
Block* inner_block =
factory()->NewBlock(NULL, 3, false, RelocInfo::kNoPosition);
{
BlockState block_state(&scope_, inner_scope);
Block* ignore_completion_block = factory()->NewBlock(
NULL, names->length() + 3, true, RelocInfo::kNoPosition);
ZoneList<Variable*> inner_vars(names->length(), zone());
// For each let variable x:
// make statement: let/const x = temp_x.
for (int i = 0; i < names->length(); i++) {
VariableProxy* proxy = NewUnresolved(names->at(i), mode);
Declaration* declaration = factory()->NewVariableDeclaration(
proxy, mode, scope_, RelocInfo::kNoPosition);
Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
inner_vars.Add(declaration->proxy()->var(), zone());
VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i));
Assignment* assignment = factory()->NewAssignment(
Token::INIT, proxy, temp_proxy, RelocInfo::kNoPosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition);
DCHECK(init->position() != RelocInfo::kNoPosition);
proxy->var()->set_initializer_position(init->position());
ignore_completion_block->statements()->Add(assignment_statement, zone());
}
// Make statement: if (first == 1) { first = 0; } else { next; }
if (next) {
DCHECK(first);
Expression* compare = NULL;
// Make compare expression: first == 1.
{
Expression* const1 =
factory()->NewSmiLiteral(1, RelocInfo::kNoPosition);
VariableProxy* first_proxy = factory()->NewVariableProxy(first);
compare = factory()->NewCompareOperation(Token::EQ, first_proxy, const1,
RelocInfo::kNoPosition);
}
Statement* clear_first = NULL;
// Make statement: first = 0.
{
VariableProxy* first_proxy = factory()->NewVariableProxy(first);
Expression* const0 =
factory()->NewSmiLiteral(0, RelocInfo::kNoPosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, first_proxy, const0, RelocInfo::kNoPosition);
clear_first = factory()->NewExpressionStatement(assignment,
RelocInfo::kNoPosition);
}
Statement* clear_first_or_next = factory()->NewIfStatement(
compare, clear_first, next, RelocInfo::kNoPosition);
ignore_completion_block->statements()->Add(clear_first_or_next, zone());
}
Variable* flag = scope_->NewTemporary(temp_name);
// Make statement: flag = 1.
{
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, flag_proxy, const1, RelocInfo::kNoPosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition);
ignore_completion_block->statements()->Add(assignment_statement, zone());
}
// Make statement: if (!cond) break.
if (cond) {
Statement* stop =
factory()->NewBreakStatement(outer_loop, RelocInfo::kNoPosition);
Statement* noop = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
ignore_completion_block->statements()->Add(
factory()->NewIfStatement(cond, noop, stop, cond->position()),
zone());
}
inner_block->statements()->Add(ignore_completion_block, zone());
// Make cond expression for main loop: flag == 1.
Expression* flag_cond = NULL;
{
Expression* const1 = factory()->NewSmiLiteral(1, RelocInfo::kNoPosition);
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
flag_cond = factory()->NewCompareOperation(Token::EQ, flag_proxy, const1,
RelocInfo::kNoPosition);
}
// Create chain of expressions "flag = 0, temp_x = x, ..."
Statement* compound_next_statement = NULL;
{
Expression* compound_next = NULL;
// Make expression: flag = 0.
{
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
Expression* const0 =
factory()->NewSmiLiteral(0, RelocInfo::kNoPosition);
compound_next = factory()->NewAssignment(
Token::ASSIGN, flag_proxy, const0, RelocInfo::kNoPosition);
}
// Make the comma-separated list of temp_x = x assignments.
int inner_var_proxy_pos = scanner()->location().beg_pos;
for (int i = 0; i < names->length(); i++) {
VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i));
VariableProxy* proxy =
factory()->NewVariableProxy(inner_vars.at(i), inner_var_proxy_pos);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, temp_proxy, proxy, RelocInfo::kNoPosition);
compound_next = factory()->NewBinaryOperation(
Token::COMMA, compound_next, assignment, RelocInfo::kNoPosition);
}
compound_next_statement = factory()->NewExpressionStatement(
compound_next, RelocInfo::kNoPosition);
}
// Make statement: labels: for (; flag == 1; flag = 0, temp_x = x)
// Note that we re-use the original loop node, which retains its labels
// and ensures that any break or continue statements in body point to
// the right place.
loop->Initialize(NULL, flag_cond, compound_next_statement, body);
inner_block->statements()->Add(loop, zone());
// Make statement: {{if (flag == 1) break;}}
{
Expression* compare = NULL;
// Make compare expresion: flag == 1.
{
Expression* const1 =
factory()->NewSmiLiteral(1, RelocInfo::kNoPosition);
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
compare = factory()->NewCompareOperation(Token::EQ, flag_proxy, const1,
RelocInfo::kNoPosition);
}
Statement* stop =
factory()->NewBreakStatement(outer_loop, RelocInfo::kNoPosition);
Statement* empty = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
Statement* if_flag_break = factory()->NewIfStatement(
compare, stop, empty, RelocInfo::kNoPosition);
Block* ignore_completion_block =
factory()->NewBlock(NULL, 1, true, RelocInfo::kNoPosition);
ignore_completion_block->statements()->Add(if_flag_break, zone());
inner_block->statements()->Add(ignore_completion_block, zone());
}
inner_scope->set_end_position(scanner()->location().end_pos);
inner_block->set_scope(inner_scope);
}
outer_loop->Initialize(NULL, NULL, NULL, inner_block);
return outer_block;
}
Statement* Parser::ParseScopedStatement(ZoneList<const AstRawString*>* labels,
bool legacy, bool* ok) {
if (is_strict(language_mode()) || peek() != Token::FUNCTION ||
(legacy && allow_harmony_restrictive_declarations())) {
return ParseSubStatement(labels, kDisallowLabelledFunctionStatement, ok);
} else {
if (legacy) {
++use_counts_[v8::Isolate::kLegacyFunctionDeclaration];
}
// Make a block around the statement for a lexical binding
// is introduced by a FunctionDeclaration.
Scope* body_scope = NewScope(scope_, BLOCK_SCOPE);
body_scope->set_start_position(scanner()->location().beg_pos);
BlockState block_state(&scope_, body_scope);
Block* block = factory()->NewBlock(NULL, 1, false, RelocInfo::kNoPosition);
Statement* body = ParseFunctionDeclaration(CHECK_OK);
block->statements()->Add(body, zone());
body_scope->set_end_position(scanner()->location().end_pos);
body_scope = body_scope->FinalizeBlockScope();
block->set_scope(body_scope);
return block;
}
}
Statement* Parser::ParseForStatement(ZoneList<const AstRawString*>* labels,
bool* ok) {
int stmt_pos = peek_position();
Statement* init = NULL;
ZoneList<const AstRawString*> lexical_bindings(1, zone());
// Create an in-between scope for let-bound iteration variables.
Scope* for_scope = NewScope(scope_, BLOCK_SCOPE);
BlockState block_state(&scope_, for_scope);
Expect(Token::FOR, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
for_scope->set_start_position(scanner()->location().beg_pos);
for_scope->set_is_hidden();
DeclarationParsingResult parsing_result;
if (peek() != Token::SEMICOLON) {
if (peek() == Token::VAR || peek() == Token::CONST ||
(peek() == Token::LET && IsNextLetKeyword())) {
ParseVariableDeclarations(kForStatement, &parsing_result, nullptr,
CHECK_OK);
ForEachStatement::VisitMode mode = ForEachStatement::ENUMERATE;
int each_beg_pos = scanner()->location().beg_pos;
int each_end_pos = scanner()->location().end_pos;
if (CheckInOrOf(&mode, ok)) {
if (!*ok) return nullptr;
if (parsing_result.declarations.length() != 1) {
ParserTraits::ReportMessageAt(
parsing_result.bindings_loc,
MessageTemplate::kForInOfLoopMultiBindings,
ForEachStatement::VisitModeString(mode));
*ok = false;
return nullptr;
}
DeclarationParsingResult::Declaration& decl =
parsing_result.declarations[0];
if (parsing_result.first_initializer_loc.IsValid() &&
(is_strict(language_mode()) || mode == ForEachStatement::ITERATE ||
IsLexicalVariableMode(parsing_result.descriptor.mode) ||
!decl.pattern->IsVariableProxy() || allow_harmony_for_in())) {
// Only increment the use count if we would have let this through
// without the flag.
if (allow_harmony_for_in()) {
++use_counts_[v8::Isolate::kForInInitializer];
}
ParserTraits::ReportMessageAt(
parsing_result.first_initializer_loc,
MessageTemplate::kForInOfLoopInitializer,
ForEachStatement::VisitModeString(mode));
*ok = false;
return nullptr;
}
Block* init_block = nullptr;
// special case for legacy for (var/const x =.... in)
if (!IsLexicalVariableMode(parsing_result.descriptor.mode) &&
decl.pattern->IsVariableProxy() && decl.initializer != nullptr) {
DCHECK(!allow_harmony_for_in());
++use_counts_[v8::Isolate::kForInInitializer];
const AstRawString* name =
decl.pattern->AsVariableProxy()->raw_name();
VariableProxy* single_var = scope_->NewUnresolved(
factory(), name, Variable::NORMAL, each_beg_pos, each_end_pos);
init_block = factory()->NewBlock(
nullptr, 2, true, parsing_result.descriptor.declaration_pos);
init_block->statements()->Add(
factory()->NewExpressionStatement(
factory()->NewAssignment(Token::ASSIGN, single_var,
decl.initializer,
RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
zone());
}
// Rewrite a for-in/of statement of the form
//
// for (let/const/var x in/of e) b
//
// into
//
// {
// <let x' be a temporary variable>
// for (x' in/of e) {
// let/const/var x;
// x = x';
// b;
// }
// let x; // for TDZ
// }
Variable* temp =
scope_->NewTemporary(ast_value_factory()->dot_for_string());
ForEachStatement* loop =
factory()->NewForEachStatement(mode, labels, stmt_pos);
Target target(&this->target_stack_, loop);
int each_keyword_position = scanner()->location().beg_pos;
Expression* enumerable;
if (mode == ForEachStatement::ITERATE) {
ExpressionClassifier classifier(this);
enumerable = ParseAssignmentExpression(true, &classifier, CHECK_OK);
RewriteNonPattern(&classifier, CHECK_OK);
} else {
enumerable = ParseExpression(true, CHECK_OK);
}
Expect(Token::RPAREN, CHECK_OK);
Scope* body_scope = NewScope(scope_, BLOCK_SCOPE);
body_scope->set_start_position(scanner()->location().beg_pos);
Block* body_block =
factory()->NewBlock(NULL, 3, false, RelocInfo::kNoPosition);
{
ReturnExprScope no_tail_calls(function_state_,
ReturnExprContext::kInsideForInOfBody);
BlockState block_state(&scope_, body_scope);
Statement* body = ParseScopedStatement(NULL, true, CHECK_OK);
auto each_initialization_block =
factory()->NewBlock(nullptr, 1, true, RelocInfo::kNoPosition);
{
auto descriptor = parsing_result.descriptor;
descriptor.declaration_pos = RelocInfo::kNoPosition;
descriptor.initialization_pos = RelocInfo::kNoPosition;
decl.initializer = factory()->NewVariableProxy(temp);
PatternRewriter::DeclareAndInitializeVariables(
each_initialization_block, &descriptor, &decl,
IsLexicalVariableMode(descriptor.mode) ? &lexical_bindings
: nullptr,
CHECK_OK);
}
body_block->statements()->Add(each_initialization_block, zone());
body_block->statements()->Add(body, zone());
VariableProxy* temp_proxy =
factory()->NewVariableProxy(temp, each_beg_pos, each_end_pos);
InitializeForEachStatement(loop, temp_proxy, enumerable, body_block,
each_keyword_position);
}
body_scope->set_end_position(scanner()->location().end_pos);
body_scope = body_scope->FinalizeBlockScope();
body_block->set_scope(body_scope);
// Create a TDZ for any lexically-bound names.
if (IsLexicalVariableMode(parsing_result.descriptor.mode)) {
DCHECK_NULL(init_block);
init_block =
factory()->NewBlock(nullptr, 1, false, RelocInfo::kNoPosition);
for (int i = 0; i < lexical_bindings.length(); ++i) {
// TODO(adamk): This needs to be some sort of special
// INTERNAL variable that's invisible to the debugger
// but visible to everything else.
VariableProxy* tdz_proxy =
NewUnresolved(lexical_bindings[i], LET);
Declaration* tdz_decl = factory()->NewVariableDeclaration(
tdz_proxy, LET, scope_, RelocInfo::kNoPosition);
Variable* tdz_var = Declare(
tdz_decl, DeclarationDescriptor::NORMAL, true, CHECK_OK);
tdz_var->set_initializer_position(position());
}
}
Statement* final_loop = loop->IsForOfStatement()
? FinalizeForOfStatement(
loop->AsForOfStatement(), RelocInfo::kNoPosition)
: loop;
for_scope->set_end_position(scanner()->location().end_pos);
for_scope = for_scope->FinalizeBlockScope();
// Parsed for-in loop w/ variable declarations.
if (init_block != nullptr) {
init_block->statements()->Add(final_loop, zone());
init_block->set_scope(for_scope);
return init_block;
} else {
DCHECK_NULL(for_scope);
return final_loop;
}
} else {
init = parsing_result.BuildInitializationBlock(
IsLexicalVariableMode(parsing_result.descriptor.mode)
? &lexical_bindings
: nullptr,
CHECK_OK);
}
} else {
int lhs_beg_pos = peek_position();
ExpressionClassifier classifier(this);
Expression* expression = ParseExpression(false, &classifier, CHECK_OK);
int lhs_end_pos = scanner()->location().end_pos;
ForEachStatement::VisitMode mode = ForEachStatement::ENUMERATE;
bool is_for_each = CheckInOrOf(&mode, ok);
if (!*ok) return nullptr;
bool is_destructuring = is_for_each && (expression->IsArrayLiteral() ||
expression->IsObjectLiteral());
if (is_destructuring) {
ValidateAssignmentPattern(&classifier, CHECK_OK);
} else {
RewriteNonPattern(&classifier, CHECK_OK);
}
if (is_for_each) {
if (!is_destructuring) {
expression = this->CheckAndRewriteReferenceExpression(
expression, lhs_beg_pos, lhs_end_pos,
MessageTemplate::kInvalidLhsInFor, kSyntaxError, CHECK_OK);
}
ForEachStatement* loop =
factory()->NewForEachStatement(mode, labels, stmt_pos);
Target target(&this->target_stack_, loop);
int each_keyword_position = scanner()->location().beg_pos;
Expression* enumerable;
if (mode == ForEachStatement::ITERATE) {
ExpressionClassifier classifier(this);
enumerable = ParseAssignmentExpression(true, &classifier, CHECK_OK);
RewriteNonPattern(&classifier, CHECK_OK);
} else {
enumerable = ParseExpression(true, CHECK_OK);
}
Expect(Token::RPAREN, CHECK_OK);
// For legacy compat reasons, give for loops similar treatment to
// if statements in allowing a function declaration for a body
Statement* body = ParseScopedStatement(NULL, true, CHECK_OK);
InitializeForEachStatement(loop, expression, enumerable, body,
each_keyword_position);
Statement* final_loop = loop->IsForOfStatement()
? FinalizeForOfStatement(
loop->AsForOfStatement(), RelocInfo::kNoPosition)
: loop;
for_scope->set_end_position(scanner()->location().end_pos);
for_scope = for_scope->FinalizeBlockScope();
DCHECK(for_scope == nullptr);
return final_loop;
} else {
init = factory()->NewExpressionStatement(expression, lhs_beg_pos);
}
}
}
// Standard 'for' loop
ForStatement* loop = factory()->NewForStatement(labels, stmt_pos);
Target target(&this->target_stack_, loop);
// Parsed initializer at this point.
Expect(Token::SEMICOLON, CHECK_OK);
Expression* cond = NULL;
Statement* next = NULL;
Statement* body = NULL;
// If there are let bindings, then condition and the next statement of the
// for loop must be parsed in a new scope.
Scope* inner_scope = scope_;
if (lexical_bindings.length() > 0) {
inner_scope = NewScope(for_scope, BLOCK_SCOPE);
inner_scope->set_start_position(scanner()->location().beg_pos);
}
{
BlockState block_state(&scope_, inner_scope);
if (peek() != Token::SEMICOLON) {
cond = ParseExpression(true, CHECK_OK);
}
Expect(Token::SEMICOLON, CHECK_OK);
if (peek() != Token::RPAREN) {
Expression* exp = ParseExpression(true, CHECK_OK);
next = factory()->NewExpressionStatement(exp, exp->position());
}
Expect(Token::RPAREN, CHECK_OK);
body = ParseScopedStatement(NULL, true, CHECK_OK);
}
Statement* result = NULL;
if (lexical_bindings.length() > 0) {
BlockState block_state(&scope_, for_scope);
result = DesugarLexicalBindingsInForStatement(
inner_scope, parsing_result.descriptor.mode, &lexical_bindings, loop,
init, cond, next, body, CHECK_OK);
for_scope->set_end_position(scanner()->location().end_pos);
} else {
for_scope->set_end_position(scanner()->location().end_pos);
for_scope = for_scope->FinalizeBlockScope();
if (for_scope) {
// Rewrite a for statement of the form
// for (const x = i; c; n) b
//
// into
//
// {
// const x = i;
// for (; c; n) b
// }
//
// or, desugar
// for (; c; n) b
// into
// {
// for (; c; n) b
// }
// just in case b introduces a lexical binding some other way, e.g., if b
// is a FunctionDeclaration.
Block* block =
factory()->NewBlock(NULL, 2, false, RelocInfo::kNoPosition);
if (init != nullptr) {
block->statements()->Add(init, zone());
}
block->statements()->Add(loop, zone());
block->set_scope(for_scope);
loop->Initialize(NULL, cond, next, body);
result = block;
} else {
loop->Initialize(init, cond, next, body);
result = loop;
}
}
return result;
}
DebuggerStatement* Parser::ParseDebuggerStatement(bool* ok) {
// In ECMA-262 'debugger' is defined as a reserved keyword. In some browser
// contexts this is used as a statement which invokes the debugger as i a
// break point is present.
// DebuggerStatement ::
// 'debugger' ';'
int pos = peek_position();
Expect(Token::DEBUGGER, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return factory()->NewDebuggerStatement(pos);
}
bool CompileTimeValue::IsCompileTimeValue(Expression* expression) {
if (expression->IsLiteral()) return true;
MaterializedLiteral* lit = expression->AsMaterializedLiteral();
return lit != NULL && lit->is_simple();
}
Handle<FixedArray> CompileTimeValue::GetValue(Isolate* isolate,
Expression* expression) {
Factory* factory = isolate->factory();
DCHECK(IsCompileTimeValue(expression));
Handle<FixedArray> result = factory->NewFixedArray(2, TENURED);
ObjectLiteral* object_literal = expression->AsObjectLiteral();
if (object_literal != NULL) {
DCHECK(object_literal->is_simple());
if (object_literal->fast_elements()) {
result->set(kLiteralTypeSlot, Smi::FromInt(OBJECT_LITERAL_FAST_ELEMENTS));
} else {
result->set(kLiteralTypeSlot, Smi::FromInt(OBJECT_LITERAL_SLOW_ELEMENTS));
}
result->set(kElementsSlot, *object_literal->constant_properties());
} else {
ArrayLiteral* array_literal = expression->AsArrayLiteral();
DCHECK(array_literal != NULL && array_literal->is_simple());
result->set(kLiteralTypeSlot, Smi::FromInt(ARRAY_LITERAL));
result->set(kElementsSlot, *array_literal->constant_elements());
}
return result;
}
CompileTimeValue::LiteralType CompileTimeValue::GetLiteralType(
Handle<FixedArray> value) {
Smi* literal_type = Smi::cast(value->get(kLiteralTypeSlot));
return static_cast<LiteralType>(literal_type->value());
}
Handle<FixedArray> CompileTimeValue::GetElements(Handle<FixedArray> value) {
return Handle<FixedArray>(FixedArray::cast(value->get(kElementsSlot)));
}
void ParserTraits::ParseArrowFunctionFormalParameters(
ParserFormalParameters* parameters, Expression* expr, int end_pos,
bool* ok) {
// ArrowFunctionFormals ::
// Binary(Token::COMMA, NonTailArrowFunctionFormals, Tail)
// Tail
// NonTailArrowFunctionFormals ::
// Binary(Token::COMMA, NonTailArrowFunctionFormals, VariableProxy)
// VariableProxy
// Tail ::
// VariableProxy
// Spread(VariableProxy)
//
// As we need to visit the parameters in left-to-right order, we recurse on
// the left-hand side of comma expressions.
//
if (expr->IsBinaryOperation()) {
BinaryOperation* binop = expr->AsBinaryOperation();
// The classifier has already run, so we know that the expression is a valid
// arrow function formals production.
DCHECK_EQ(binop->op(), Token::COMMA);
Expression* left = binop->left();
Expression* right = binop->right();
int comma_pos = binop->position();
ParseArrowFunctionFormalParameters(parameters, left, comma_pos, ok);
if (!*ok) return;
// LHS of comma expression should be unparenthesized.
expr = right;
}
// Only the right-most expression may be a rest parameter.
DCHECK(!parameters->has_rest);
bool is_rest = expr->IsSpread();
if (is_rest) {
expr = expr->AsSpread()->expression();
parameters->has_rest = true;
}
if (parameters->is_simple) {
parameters->is_simple = !is_rest && expr->IsVariableProxy();
}
Expression* initializer = nullptr;
if (expr->IsVariableProxy()) {
// When the formal parameter was originally seen, it was parsed as a
// VariableProxy and recorded as unresolved in the scope. Here we undo that
// parse-time side-effect for parameters that are single-names (not
// patterns; for patterns that happens uniformly in
// PatternRewriter::VisitVariableProxy).
parser_->scope_->RemoveUnresolved(expr->AsVariableProxy());
} else if (expr->IsAssignment()) {
Assignment* assignment = expr->AsAssignment();
DCHECK(!assignment->is_compound());
initializer = assignment->value();
expr = assignment->target();
// TODO(adamk): Only call this if necessary.
RewriteParameterInitializerScope(parser_->stack_limit(), initializer,
parser_->scope_, parameters->scope);
}
AddFormalParameter(parameters, expr, initializer, end_pos, is_rest);
}
void ParserTraits::ParseAsyncArrowSingleExpressionBody(
ZoneList<Statement*>* body, bool accept_IN,
Type::ExpressionClassifier* classifier, int pos, bool* ok) {
parser_->DesugarAsyncFunctionBody(
parser_->ast_value_factory()->empty_string(), parser_->scope_, body,
classifier, kAsyncArrowFunction, FunctionBody::SingleExpression,
accept_IN, pos, ok);
}
void Parser::DesugarAsyncFunctionBody(const AstRawString* function_name,
Scope* scope, ZoneList<Statement*>* body,
ExpressionClassifier* classifier,
FunctionKind kind, FunctionBody body_type,
bool accept_IN, int pos, bool* ok) {
// function async_function() {
// try {
// .generator_object = %CreateGeneratorObject();
// ... function body ...
// } catch (e) {
// return Promise.reject(e);
// }
// }
scope->ForceContextAllocation();
Variable* temp =
scope_->NewTemporary(ast_value_factory()->dot_generator_object_string());
function_state_->set_generator_object_variable(temp);
Expression* init_generator_variable = factory()->NewAssignment(
Token::INIT, factory()->NewVariableProxy(temp),
BuildCreateJSGeneratorObject(pos, kind), RelocInfo::kNoPosition);
body->Add(factory()->NewExpressionStatement(init_generator_variable,
RelocInfo::kNoPosition),
zone());
Block* try_block = factory()->NewBlock(NULL, 8, true, RelocInfo::kNoPosition);
ZoneList<Statement*>* inner_body = try_block->statements();
Expression* return_value = nullptr;
if (body_type == FunctionBody::Normal) {
ParseStatementList(inner_body, Token::RBRACE, ok);
if (!*ok) return;
return_value = factory()->NewUndefinedLiteral(RelocInfo::kNoPosition);
} else {
return_value = ParseAssignmentExpression(accept_IN, classifier, ok);
if (!*ok) return;
ParserTraits::RewriteNonPattern(classifier, ok);
if (!*ok) return;
}
return_value = BuildPromiseResolve(return_value, return_value->position());
inner_body->Add(
factory()->NewReturnStatement(return_value, return_value->position()),
zone());
body->Add(BuildRejectPromiseOnException(try_block), zone());
scope->set_end_position(scanner()->location().end_pos);
}
DoExpression* Parser::ParseDoExpression(bool* ok) {
// AssignmentExpression ::
// do '{' StatementList '}'
int pos = peek_position();
Expect(Token::DO, CHECK_OK);
Variable* result =
scope_->NewTemporary(ast_value_factory()->dot_result_string());
Block* block = ParseBlock(nullptr, false, CHECK_OK);
DoExpression* expr = factory()->NewDoExpression(block, result, pos);
if (!Rewriter::Rewrite(this, expr, ast_value_factory())) {
*ok = false;
return nullptr;
}
block->set_scope(block->scope()->FinalizeBlockScope());
return expr;
}
void ParserTraits::ParseArrowFunctionFormalParameterList(
ParserFormalParameters* parameters, Expression* expr,
const Scanner::Location& params_loc,
Scanner::Location* duplicate_loc, bool* ok) {
if (expr->IsEmptyParentheses()) return;
ParseArrowFunctionFormalParameters(parameters, expr, params_loc.end_pos, ok);
if (!*ok) return;
if (parameters->Arity() > Code::kMaxArguments) {
ReportMessageAt(params_loc, MessageTemplate::kMalformedArrowFunParamList);
*ok = false;
return;
}
Type::ExpressionClassifier classifier(parser_);
if (!parameters->is_simple) {
classifier.RecordNonSimpleParameter();
}
for (int i = 0; i < parameters->Arity(); ++i) {
auto parameter = parameters->at(i);
DeclareFormalParameter(parameters->scope, parameter, &classifier);
if (!duplicate_loc->IsValid()) {
*duplicate_loc = classifier.duplicate_formal_parameter_error().location;
}
}
DCHECK_EQ(parameters->is_simple, parameters->scope->has_simple_parameters());
}
void ParserTraits::ReindexLiterals(const ParserFormalParameters& parameters) {
if (parser_->function_state_->materialized_literal_count() > 0) {
AstLiteralReindexer reindexer;
for (const auto p : parameters.params) {
if (p.pattern != nullptr) reindexer.Reindex(p.pattern);
if (p.initializer != nullptr) reindexer.Reindex(p.initializer);
}
DCHECK(reindexer.count() <=
parser_->function_state_->materialized_literal_count());
}
}
FunctionLiteral* Parser::ParseFunctionLiteral(
const AstRawString* function_name, Scanner::Location function_name_location,
FunctionNameValidity function_name_validity, FunctionKind kind,
int function_token_pos, FunctionLiteral::FunctionType function_type,
LanguageMode language_mode, bool* ok) {
// Function ::
// '(' FormalParameterList? ')' '{' FunctionBody '}'
//
// Getter ::
// '(' ')' '{' FunctionBody '}'
//
// Setter ::
// '(' PropertySetParameterList ')' '{' FunctionBody '}'
int pos = function_token_pos == RelocInfo::kNoPosition
? peek_position() : function_token_pos;
bool is_generator = IsGeneratorFunction(kind);
// Anonymous functions were passed either the empty symbol or a null
// handle as the function name. Remember if we were passed a non-empty
// handle to decide whether to invoke function name inference.
bool should_infer_name = function_name == NULL;
// We want a non-null handle as the function name.
if (should_infer_name) {
function_name = ast_value_factory()->empty_string();
}
Scope* scope = NewScope(scope_, FUNCTION_SCOPE, kind);
SetLanguageMode(scope, language_mode);
ZoneList<Statement*>* body = NULL;
int arity = -1;
int materialized_literal_count = -1;
int expected_property_count = -1;
DuplicateFinder duplicate_finder(scanner()->unicode_cache());
bool should_be_used_once_hint = false;
bool has_duplicate_parameters;
FunctionLiteral::EagerCompileHint eager_compile_hint;
// Parse function.
{
AstNodeFactory function_factory(ast_value_factory());
FunctionState function_state(&function_state_, &scope_, scope, kind,
&function_factory);
scope_->SetScopeName(function_name);
ExpressionClassifier formals_classifier(this, &duplicate_finder);
eager_compile_hint = function_state_->this_function_is_parenthesized()
? FunctionLiteral::kShouldEagerCompile
: FunctionLiteral::kShouldLazyCompile;
if (is_generator) {
// For generators, allocating variables in contexts is currently a win
// because it minimizes the work needed to suspend and resume an
// activation. The machine code produced for generators (by full-codegen)
// relies on this forced context allocation, but not in an essential way.
scope_->ForceContextAllocation();
// Calling a generator returns a generator object. That object is stored
// in a temporary variable, a definition that is used by "yield"
// expressions. This also marks the FunctionState as a generator.
Variable* temp = scope_->NewTemporary(
ast_value_factory()->dot_generator_object_string());
function_state.set_generator_object_variable(temp);
}
Expect(Token::LPAREN, CHECK_OK);
int start_position = scanner()->location().beg_pos;
scope_->set_start_position(start_position);
ParserFormalParameters formals(scope);
ParseFormalParameterList(&formals, &formals_classifier, CHECK_OK);
arity = formals.Arity();
Expect(Token::RPAREN, CHECK_OK);
int formals_end_position = scanner()->location().end_pos;
CheckArityRestrictions(arity, kind, formals.has_rest, start_position,
formals_end_position, CHECK_OK);
Expect(Token::LBRACE, CHECK_OK);
// Don't include the rest parameter into the function's formal parameter
// count (esp. the SharedFunctionInfo::internal_formal_parameter_count,
// which says whether we need to create an arguments adaptor frame).
if (formals.has_rest) arity--;
// Determine if the function can be parsed lazily. Lazy parsing is different
// from lazy compilation; we need to parse more eagerly than we compile.
// We can only parse lazily if we also compile lazily. The heuristics for
// lazy compilation are:
// - It must not have been prohibited by the caller to Parse (some callers
// need a full AST).
// - The outer scope must allow lazy compilation of inner functions.
// - The function mustn't be a function expression with an open parenthesis
// before; we consider that a hint that the function will be called
// immediately, and it would be a waste of time to make it lazily
// compiled.
// These are all things we can know at this point, without looking at the
// function itself.
// In addition, we need to distinguish between these cases:
// (function foo() {
// bar = function() { return 1; }
// })();
// and
// (function foo() {
// var a = 1;
// bar = function() { return a; }
// })();
// Now foo will be parsed eagerly and compiled eagerly (optimization: assume
// parenthesis before the function means that it will be called
// immediately). The inner function *must* be parsed eagerly to resolve the
// possible reference to the variable in foo's scope. However, it's possible
// that it will be compiled lazily.
// To make this additional case work, both Parser and PreParser implement a
// logic where only top-level functions will be parsed lazily.
bool is_lazily_parsed = mode() == PARSE_LAZILY &&
scope_->AllowsLazyParsing() &&
!function_state_->this_function_is_parenthesized();
// Eager or lazy parse?
// If is_lazily_parsed, we'll parse lazy. If we can set a bookmark, we'll
// pass it to SkipLazyFunctionBody, which may use it to abort lazy
// parsing if it suspect that wasn't a good idea. If so, or if we didn't
// try to lazy parse in the first place, we'll have to parse eagerly.
Scanner::BookmarkScope bookmark(scanner());
if (is_lazily_parsed) {
Scanner::BookmarkScope* maybe_bookmark =
bookmark.Set() ? &bookmark : nullptr;
SkipLazyFunctionBody(&materialized_literal_count,
&expected_property_count, /*CHECK_OK*/ ok,
maybe_bookmark);
materialized_literal_count += formals.materialized_literals_count +
function_state.materialized_literal_count();
if (bookmark.HasBeenReset()) {
// Trigger eager (re-)parsing, just below this block.
is_lazily_parsed = false;
// This is probably an initialization function. Inform the compiler it
// should also eager-compile this function, and that we expect it to be
// used once.
eager_compile_hint = FunctionLiteral::kShouldEagerCompile;
should_be_used_once_hint = true;
}
}
if (!is_lazily_parsed) {
// Determine whether the function body can be discarded after parsing.
// The preconditions are:
// - Lazy compilation has to be enabled.
// - Neither V8 natives nor native function declarations can be allowed,
// since parsing one would retroactively force the function to be
// eagerly compiled.
// - The invoker of this parser can't depend on the AST being eagerly
// built (either because the function is about to be compiled, or
// because the AST is going to be inspected for some reason).
// - Because of the above, we can't be attempting to parse a
// FunctionExpression; even without enclosing parentheses it might be
// immediately invoked.
// - The function literal shouldn't be hinted to eagerly compile.
// - For asm.js functions the body needs to be available when module
// validation is active, because we examine the entire module at once.
bool use_temp_zone =
FLAG_lazy && !allow_natives() && extension_ == NULL && allow_lazy() &&
function_type == FunctionLiteral::kDeclaration &&
eager_compile_hint != FunctionLiteral::kShouldEagerCompile &&
!(FLAG_validate_asm && scope->asm_function());
// Open a new BodyScope, which sets our AstNodeFactory to allocate in the
// new temporary zone if the preconditions are satisfied, and ensures that
// the previous zone is always restored after parsing the body.
// For the purpose of scope analysis, some ZoneObjects allocated by the
// factory must persist after the function body is thrown away and
// temp_zone is deallocated. These objects are instead allocated in a
// parser-persistent zone (see parser_zone_ in AstNodeFactory).
{
Zone temp_zone(zone()->allocator());
AstNodeFactory::BodyScope inner(factory(), &temp_zone, use_temp_zone);
body = ParseEagerFunctionBody(function_name, pos, formals, kind,
function_type, CHECK_OK);
}
materialized_literal_count = function_state.materialized_literal_count();
expected_property_count = function_state.expected_property_count();
if (use_temp_zone) {
// If the preconditions are correct the function body should never be
// accessed, but do this anyway for better behaviour if they're wrong.
body = NULL;
}
}
// Parsing the body may change the language mode in our scope.
language_mode = scope->language_mode();
// Validate name and parameter names. We can do this only after parsing the
// function, since the function can declare itself strict.
CheckFunctionName(language_mode, function_name, function_name_validity,
function_name_location, CHECK_OK);
const bool allow_duplicate_parameters =
is_sloppy(language_mode) && formals.is_simple && !IsConciseMethod(kind);
ValidateFormalParameters(&formals_classifier, language_mode,
allow_duplicate_parameters, CHECK_OK);
if (is_strict(language_mode)) {
CheckStrictOctalLiteral(scope->start_position(), scope->end_position(),
CHECK_OK);
CheckDecimalLiteralWithLeadingZero(use_counts_, scope->start_position(),
scope->end_position());
}
if (is_sloppy(language_mode)) {
InsertSloppyBlockFunctionVarBindings(scope, CHECK_OK);
}
CheckConflictingVarDeclarations(scope, CHECK_OK);
if (body) {
// If body can be inspected, rewrite queued destructuring assignments
ParserTraits::RewriteDestructuringAssignments();
}
has_duplicate_parameters =
!formals_classifier.is_valid_formal_parameter_list_without_duplicates();
}
FunctionLiteral::ParameterFlag duplicate_parameters =
has_duplicate_parameters ? FunctionLiteral::kHasDuplicateParameters
: FunctionLiteral::kNoDuplicateParameters;
FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
function_name, scope, body, materialized_literal_count,
expected_property_count, arity, duplicate_parameters, function_type,
eager_compile_hint, kind, pos);
function_literal->set_function_token_position(function_token_pos);
if (should_be_used_once_hint)
function_literal->set_should_be_used_once_hint();
if (fni_ != NULL && should_infer_name) fni_->AddFunction(function_literal);
return function_literal;
}
Expression* Parser::ParseAsyncFunctionExpression(bool* ok) {
// AsyncFunctionDeclaration ::
// async [no LineTerminator here] function ( FormalParameters[Await] )
// { AsyncFunctionBody }
//
// async [no LineTerminator here] function BindingIdentifier[Await]
// ( FormalParameters[Await] ) { AsyncFunctionBody }
DCHECK_EQ(scanner()->current_token(), Token::ASYNC);
int pos = position();
Expect(Token::FUNCTION, CHECK_OK);
bool is_strict_reserved = false;
const AstRawString* name = nullptr;
FunctionLiteral::FunctionType type = FunctionLiteral::kAnonymousExpression;
if (peek_any_identifier()) {
type = FunctionLiteral::kNamedExpression;
name = ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
if (this->IsAwait(name)) {
ReportMessageAt(scanner()->location(),
MessageTemplate::kAwaitBindingIdentifier);
*ok = false;
return nullptr;
}
}
return ParseFunctionLiteral(name, scanner()->location(),
is_strict_reserved ? kFunctionNameIsStrictReserved
: kFunctionNameValidityUnknown,
FunctionKind::kAsyncFunction, pos, type,
language_mode(), CHECK_OK);
}
void Parser::SkipLazyFunctionBody(int* materialized_literal_count,
int* expected_property_count, bool* ok,
Scanner::BookmarkScope* bookmark) {
DCHECK_IMPLIES(bookmark, bookmark->HasBeenSet());
if (produce_cached_parse_data()) CHECK(log_);
int function_block_pos = position();
if (consume_cached_parse_data() && !cached_parse_data_->rejected()) {
// If we have cached data, we use it to skip parsing the function body. The
// data contains the information we need to construct the lazy function.
FunctionEntry entry =
cached_parse_data_->GetFunctionEntry(function_block_pos);
// Check that cached data is valid. If not, mark it as invalid (the embedder
// handles it). Note that end position greater than end of stream is safe,
// and hard to check.
if (entry.is_valid() && entry.end_pos() > function_block_pos) {
scanner()->SeekForward(entry.end_pos() - 1);
scope_->set_end_position(entry.end_pos());
Expect(Token::RBRACE, ok);
if (!*ok) {
return;
}
total_preparse_skipped_ += scope_->end_position() - function_block_pos;
*materialized_literal_count = entry.literal_count();
*expected_property_count = entry.property_count();
SetLanguageMode(scope_, entry.language_mode());
if (entry.uses_super_property()) scope_->RecordSuperPropertyUsage();
if (entry.calls_eval()) scope_->RecordEvalCall();
return;
}
cached_parse_data_->Reject();
}
// With no cached data, we partially parse the function, without building an
// AST. This gathers the data needed to build a lazy function.
SingletonLogger logger;
PreParser::PreParseResult result =
ParseLazyFunctionBodyWithPreParser(&logger, bookmark);
if (bookmark && bookmark->HasBeenReset()) {
return; // Return immediately if pre-parser devided to abort parsing.
}
if (result == PreParser::kPreParseStackOverflow) {
// Propagate stack overflow.
set_stack_overflow();
*ok = false;
return;
}
if (logger.has_error()) {
ParserTraits::ReportMessageAt(
Scanner::Location(logger.start(), logger.end()), logger.message(),
logger.argument_opt(), logger.error_type());
*ok = false;
return;
}
scope_->set_end_position(logger.end());
Expect(Token::RBRACE, ok);
if (!*ok) {
return;
}
total_preparse_skipped_ += scope_->end_position() - function_block_pos;
*materialized_literal_count = logger.literals();
*expected_property_count = logger.properties();
SetLanguageMode(scope_, logger.language_mode());
if (logger.uses_super_property()) {
scope_->RecordSuperPropertyUsage();
}
if (logger.calls_eval()) {
scope_->RecordEvalCall();
}
if (produce_cached_parse_data()) {
DCHECK(log_);
// Position right after terminal '}'.
int body_end = scanner()->location().end_pos;
log_->LogFunction(function_block_pos, body_end, *materialized_literal_count,
*expected_property_count, scope_->language_mode(),
scope_->uses_super_property(), scope_->calls_eval());
}
}
Statement* Parser::BuildAssertIsCoercible(Variable* var) {
// if (var === null || var === undefined)
// throw /* type error kNonCoercible) */;
Expression* condition = factory()->NewBinaryOperation(
Token::OR, factory()->NewCompareOperation(
Token::EQ_STRICT, factory()->NewVariableProxy(var),
factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
factory()->NewCompareOperation(
Token::EQ_STRICT, factory()->NewVariableProxy(var),
factory()->NewNullLiteral(RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
RelocInfo::kNoPosition);
Expression* throw_type_error = this->NewThrowTypeError(
MessageTemplate::kNonCoercible, ast_value_factory()->empty_string(),
RelocInfo::kNoPosition);
IfStatement* if_statement = factory()->NewIfStatement(
condition, factory()->NewExpressionStatement(throw_type_error,
RelocInfo::kNoPosition),
factory()->NewEmptyStatement(RelocInfo::kNoPosition),
RelocInfo::kNoPosition);
return if_statement;
}
class InitializerRewriter : public AstExpressionVisitor {
public:
InitializerRewriter(uintptr_t stack_limit, Expression* root, Parser* parser,
Scope* scope)
: AstExpressionVisitor(stack_limit, root),
parser_(parser),
scope_(scope) {}
private:
void VisitExpression(Expression* expr) override {
RewritableExpression* to_rewrite = expr->AsRewritableExpression();
if (to_rewrite == nullptr || to_rewrite->is_rewritten()) return;
Parser::PatternRewriter::RewriteDestructuringAssignment(parser_, to_rewrite,
scope_);
}
// Code in function literals does not need to be eagerly rewritten, it will be
// rewritten when scheduled.
void VisitFunctionLiteral(FunctionLiteral* expr) override {}
private:
Parser* parser_;
Scope* scope_;
};
void Parser::RewriteParameterInitializer(Expression* expr, Scope* scope) {
InitializerRewriter rewriter(stack_limit_, expr, this, scope);
rewriter.Run();
}
Block* Parser::BuildParameterInitializationBlock(
const ParserFormalParameters& parameters, bool* ok) {
DCHECK(!parameters.is_simple);
DCHECK(scope_->is_function_scope());
Block* init_block =
factory()->NewBlock(NULL, 1, true, RelocInfo::kNoPosition);
for (int i = 0; i < parameters.params.length(); ++i) {
auto parameter = parameters.params[i];
if (parameter.is_rest && parameter.pattern->IsVariableProxy()) break;
DeclarationDescriptor descriptor;
descriptor.declaration_kind = DeclarationDescriptor::PARAMETER;
descriptor.parser = this;
descriptor.scope = scope_;
descriptor.hoist_scope = nullptr;
descriptor.mode = LET;
descriptor.declaration_pos = parameter.pattern->position();
// The position that will be used by the AssignmentExpression
// which copies from the temp parameter to the pattern.
//
// TODO(adamk): Should this be RelocInfo::kNoPosition, since
// it's just copying from a temp var to the real param var?
descriptor.initialization_pos = parameter.pattern->position();
// The initializer position which will end up in,
// Variable::initializer_position(), used for hole check elimination.
int initializer_position = parameter.pattern->position();
Expression* initial_value =
factory()->NewVariableProxy(parameters.scope->parameter(i));
if (parameter.initializer != nullptr) {
// IS_UNDEFINED($param) ? initializer : $param
// Ensure initializer is rewritten
RewriteParameterInitializer(parameter.initializer, scope_);
auto condition = factory()->NewCompareOperation(
Token::EQ_STRICT,
factory()->NewVariableProxy(parameters.scope->parameter(i)),
factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
RelocInfo::kNoPosition);
initial_value = factory()->NewConditional(
condition, parameter.initializer, initial_value,
RelocInfo::kNoPosition);
descriptor.initialization_pos = parameter.initializer->position();
initializer_position = parameter.initializer_end_position;
}
Scope* param_scope = scope_;
Block* param_block = init_block;
if (!parameter.is_simple() && scope_->calls_sloppy_eval()) {
param_scope = NewScope(scope_, BLOCK_SCOPE);
param_scope->set_is_declaration_scope();
param_scope->set_start_position(descriptor.initialization_pos);
param_scope->set_end_position(parameter.initializer_end_position);
param_scope->RecordEvalCall();
param_block = factory()->NewBlock(NULL, 8, true, RelocInfo::kNoPosition);
param_block->set_scope(param_scope);
descriptor.hoist_scope = scope_;
}
{
BlockState block_state(&scope_, param_scope);
DeclarationParsingResult::Declaration decl(
parameter.pattern, initializer_position, initial_value);
PatternRewriter::DeclareAndInitializeVariables(param_block, &descriptor,
&decl, nullptr, CHECK_OK);
}
if (!parameter.is_simple() && scope_->calls_sloppy_eval()) {
param_scope = param_scope->FinalizeBlockScope();
if (param_scope != nullptr) {
CheckConflictingVarDeclarations(param_scope, CHECK_OK);
}
init_block->statements()->Add(param_block, zone());
}
}
return init_block;
}
Block* Parser::BuildRejectPromiseOnException(Block* block) {
// try { <block> } catch (error) { return Promise.reject(error); }
Block* try_block = block;
Scope* catch_scope = NewScope(scope_, CATCH_SCOPE);
catch_scope->set_is_hidden();
Variable* catch_variable =
catch_scope->DeclareLocal(ast_value_factory()->dot_catch_string(), VAR,
kCreatedInitialized, Variable::NORMAL);
Block* catch_block =
factory()->NewBlock(nullptr, 1, true, RelocInfo::kNoPosition);
Expression* promise_reject = BuildPromiseReject(
factory()->NewVariableProxy(catch_variable), RelocInfo::kNoPosition);
ReturnStatement* return_promise_reject =
factory()->NewReturnStatement(promise_reject, RelocInfo::kNoPosition);
catch_block->statements()->Add(return_promise_reject, zone());
TryStatement* try_catch_statement =
factory()->NewTryCatchStatement(try_block, catch_scope, catch_variable,
catch_block, RelocInfo::kNoPosition);
block = factory()->NewBlock(nullptr, 1, true, RelocInfo::kNoPosition);
block->statements()->Add(try_catch_statement, zone());
return block;
}
Expression* Parser::BuildCreateJSGeneratorObject(int pos, FunctionKind kind) {
DCHECK_NOT_NULL(function_state_->generator_object_variable());
ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(2, zone());
args->Add(factory()->NewThisFunction(pos), zone());
args->Add(IsArrowFunction(kind)
? GetLiteralUndefined(pos)
: ThisExpression(scope_, factory(), RelocInfo::kNoPosition),
zone());
return factory()->NewCallRuntime(Runtime::kCreateJSGeneratorObject, args,
pos);
}
Expression* Parser::BuildPromiseResolve(Expression* value, int pos) {
ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(1, zone());
args->Add(value, zone());
return factory()->NewCallRuntime(Context::PROMISE_CREATE_RESOLVED_INDEX, args,
pos);
}
Expression* Parser::BuildPromiseReject(Expression* value, int pos) {
ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(1, zone());
args->Add(value, zone());
return factory()->NewCallRuntime(Context::PROMISE_CREATE_REJECTED_INDEX, args,
pos);
}
ZoneList<Statement*>* Parser::ParseEagerFunctionBody(
const AstRawString* function_name, int pos,
const ParserFormalParameters& parameters, FunctionKind kind,
FunctionLiteral::FunctionType function_type, bool* ok) {
// Everything inside an eagerly parsed function will be parsed eagerly
// (see comment above).
ParsingModeScope parsing_mode(this, PARSE_EAGERLY);
ZoneList<Statement*>* result = new(zone()) ZoneList<Statement*>(8, zone());
static const int kFunctionNameAssignmentIndex = 0;
if (function_type == FunctionLiteral::kNamedExpression) {
DCHECK(function_name != NULL);
// If we have a named function expression, we add a local variable
// declaration to the body of the function with the name of the
// function and let it refer to the function itself (closure).
// Not having parsed the function body, the language mode may still change,
// so we reserve a spot and create the actual const assignment later.
DCHECK_EQ(kFunctionNameAssignmentIndex, result->length());
result->Add(NULL, zone());
}
ZoneList<Statement*>* body = result;
Scope* inner_scope = scope_;
Block* inner_block = nullptr;
if (!parameters.is_simple) {
inner_scope = NewScope(scope_, BLOCK_SCOPE);
inner_scope->set_is_declaration_scope();
inner_scope->set_start_position(scanner()->location().beg_pos);
inner_block = factory()->NewBlock(NULL, 8, true, RelocInfo::kNoPosition);
inner_block->set_scope(inner_scope);
body = inner_block->statements();
}
{
BlockState block_state(&scope_, inner_scope);
if (IsGeneratorFunction(kind)) {
// We produce:
//
// try { InitialYield; ...body...; return {value: undefined, done: true} }
// finally { %_GeneratorClose(generator) }
//
// - InitialYield yields the actual generator object.
// - Any return statement inside the body will have its argument wrapped
// in a "done" iterator result object.
// - If the generator terminates for whatever reason, we must close it.
// Hence the finally clause.
Block* try_block =
factory()->NewBlock(nullptr, 3, false, RelocInfo::kNoPosition);
{
Expression* allocation = BuildCreateJSGeneratorObject(pos, kind);
VariableProxy* init_proxy = factory()->NewVariableProxy(
function_state_->generator_object_variable());
Assignment* assignment = factory()->NewAssignment(
Token::INIT, init_proxy, allocation, RelocInfo::kNoPosition);
VariableProxy* get_proxy = factory()->NewVariableProxy(
function_state_->generator_object_variable());
// The position of the yield is important for reporting the exception
// caused by calling the .throw method on a generator suspended at the
// initial yield (i.e. right after generator instantiation).
Yield* yield = factory()->NewYield(get_proxy, assignment,
scope_->start_position());
try_block->statements()->Add(
factory()->NewExpressionStatement(yield, RelocInfo::kNoPosition),
zone());
}
ParseStatementList(try_block->statements(), Token::RBRACE, CHECK_OK);
Statement* final_return = factory()->NewReturnStatement(
BuildIteratorResult(nullptr, true), RelocInfo::kNoPosition);
try_block->statements()->Add(final_return, zone());
Block* finally_block =
factory()->NewBlock(nullptr, 1, false, RelocInfo::kNoPosition);
ZoneList<Expression*>* args =
new (zone()) ZoneList<Expression*>(1, zone());
VariableProxy* call_proxy = factory()->NewVariableProxy(
function_state_->generator_object_variable());
args->Add(call_proxy, zone());
Expression* call = factory()->NewCallRuntime(
Runtime::kInlineGeneratorClose, args, RelocInfo::kNoPosition);
finally_block->statements()->Add(
factory()->NewExpressionStatement(call, RelocInfo::kNoPosition),
zone());
body->Add(factory()->NewTryFinallyStatement(try_block, finally_block,
RelocInfo::kNoPosition),
zone());
} else if (IsAsyncFunction(kind)) {
const bool accept_IN = true;
DesugarAsyncFunctionBody(function_name, inner_scope, body, nullptr, kind,
FunctionBody::Normal, accept_IN, pos, CHECK_OK);
} else {
ParseStatementList(body, Token::RBRACE, CHECK_OK);
}
if (IsSubclassConstructor(kind)) {
body->Add(
factory()->NewReturnStatement(
this->ThisExpression(scope_, factory(), RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
zone());
}
}
Expect(Token::RBRACE, CHECK_OK);
scope_->set_end_position(scanner()->location().end_pos);
if (!parameters.is_simple) {
DCHECK_NOT_NULL(inner_scope);
DCHECK_EQ(body, inner_block->statements());
SetLanguageMode(scope_, inner_scope->language_mode());
Block* init_block = BuildParameterInitializationBlock(parameters, CHECK_OK);
if (IsAsyncFunction(kind)) {
init_block = BuildRejectPromiseOnException(init_block);
}
DCHECK_NOT_NULL(init_block);
inner_scope->set_end_position(scanner()->location().end_pos);
inner_scope = inner_scope->FinalizeBlockScope();
if (inner_scope != nullptr) {
CheckConflictingVarDeclarations(inner_scope, CHECK_OK);
InsertShadowingVarBindingInitializers(inner_block);
}
result->Add(init_block, zone());
result->Add(inner_block, zone());
}
if (function_type == FunctionLiteral::kNamedExpression) {
// Now that we know the language mode, we can create the const assignment
// in the previously reserved spot.
// NOTE: We create a proxy and resolve it here so that in the
// future we can change the AST to only refer to VariableProxies
// instead of Variables and Proxies as is the case now.
VariableMode fvar_mode = is_strict(language_mode()) ? CONST : CONST_LEGACY;
Variable* fvar = new (zone())
Variable(scope_, function_name, fvar_mode, Variable::NORMAL,
kCreatedInitialized, kNotAssigned);
VariableProxy* proxy = factory()->NewVariableProxy(fvar);
VariableDeclaration* fvar_declaration = factory()->NewVariableDeclaration(
proxy, fvar_mode, scope_, RelocInfo::kNoPosition);
scope_->DeclareFunctionVar(fvar_declaration);
VariableProxy* fproxy = factory()->NewVariableProxy(fvar);
result->Set(kFunctionNameAssignmentIndex,
factory()->NewExpressionStatement(
factory()->NewAssignment(Token::INIT, fproxy,
factory()->NewThisFunction(pos),
RelocInfo::kNoPosition),
RelocInfo::kNoPosition));
}
MarkCollectedTailCallExpressions();
return result;
}
PreParser::PreParseResult Parser::ParseLazyFunctionBodyWithPreParser(
SingletonLogger* logger, Scanner::BookmarkScope* bookmark) {
// This function may be called on a background thread too; record only the
// main thread preparse times.
if (pre_parse_timer_ != NULL) {
pre_parse_timer_->Start();
}
TRACE_EVENT0("v8", "V8.PreParse");
DCHECK_EQ(Token::LBRACE, scanner()->current_token());
if (reusable_preparser_ == NULL) {
reusable_preparser_ = new PreParser(zone(), &scanner_, ast_value_factory(),
NULL, stack_limit_);
reusable_preparser_->set_allow_lazy(true);
#define SET_ALLOW(name) reusable_preparser_->set_allow_##name(allow_##name());
SET_ALLOW(natives);
SET_ALLOW(harmony_do_expressions);
SET_ALLOW(harmony_for_in);
SET_ALLOW(harmony_function_name);
SET_ALLOW(harmony_function_sent);
SET_ALLOW(harmony_exponentiation_operator);
SET_ALLOW(harmony_restrictive_declarations);
SET_ALLOW(harmony_async_await);
#undef SET_ALLOW
}
PreParser::PreParseResult result = reusable_preparser_->PreParseLazyFunction(
language_mode(), function_state_->kind(), scope_->has_simple_parameters(),
parsing_module_, logger, bookmark, use_counts_);
if (pre_parse_timer_ != NULL) {
pre_parse_timer_->Stop();
}
return result;
}
ClassLiteral* Parser::ParseClassLiteral(ExpressionClassifier* classifier,
const AstRawString* name,
Scanner::Location class_name_location,
bool name_is_strict_reserved, int pos,
bool* ok) {
// All parts of a ClassDeclaration and ClassExpression are strict code.
if (name_is_strict_reserved) {
ReportMessageAt(class_name_location,
MessageTemplate::kUnexpectedStrictReserved);
*ok = false;
return NULL;
}
if (IsEvalOrArguments(name)) {
ReportMessageAt(class_name_location, MessageTemplate::kStrictEvalArguments);
*ok = false;
return NULL;
}
Scope* block_scope = NewScope(scope_, BLOCK_SCOPE);
BlockState block_state(&scope_, block_scope);
RaiseLanguageMode(STRICT);
scope_->SetScopeName(name);
VariableProxy* proxy = NULL;
if (name != NULL) {
proxy = NewUnresolved(name, CONST);
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, CONST, block_scope, pos);
Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
}
Expression* extends = NULL;
if (Check(Token::EXTENDS)) {
block_scope->set_start_position(scanner()->location().end_pos);
ExpressionClassifier extends_classifier(this);
extends = ParseLeftHandSideExpression(&extends_classifier, CHECK_OK);
CheckNoTailCallExpressions(&extends_classifier, CHECK_OK);
RewriteNonPattern(&extends_classifier, CHECK_OK);
if (classifier != nullptr) {
classifier->Accumulate(&extends_classifier,
ExpressionClassifier::ExpressionProductions);
}
} else {
block_scope->set_start_position(scanner()->location().end_pos);
}
ClassLiteralChecker checker(this);
ZoneList<ObjectLiteral::Property*>* properties = NewPropertyList(4, zone());
FunctionLiteral* constructor = NULL;
bool has_seen_constructor = false;
Expect(Token::LBRACE, CHECK_OK);
const bool has_extends = extends != nullptr;
while (peek() != Token::RBRACE) {
if (Check(Token::SEMICOLON)) continue;
FuncNameInferrer::State fni_state(fni_);
const bool in_class = true;
bool is_computed_name = false; // Classes do not care about computed
// property names here.
ExpressionClassifier property_classifier(this);
const AstRawString* property_name = nullptr;
ObjectLiteral::Property* property = ParsePropertyDefinition(
&checker, in_class, has_extends, MethodKind::Normal, &is_computed_name,
&has_seen_constructor, &property_classifier, &property_name, CHECK_OK);
RewriteNonPattern(&property_classifier, CHECK_OK);
if (classifier != nullptr) {
classifier->Accumulate(&property_classifier,
ExpressionClassifier::ExpressionProductions);
}
if (has_seen_constructor && constructor == NULL) {
constructor = GetPropertyValue(property)->AsFunctionLiteral();
DCHECK_NOT_NULL(constructor);
constructor->set_raw_name(
name != nullptr ? name : ast_value_factory()->empty_string());
} else {
properties->Add(property, zone());
}
if (fni_ != NULL) fni_->Infer();
if (allow_harmony_function_name() &&
property_name != ast_value_factory()->constructor_string()) {
SetFunctionNameFromPropertyName(property, property_name);
}
}
Expect(Token::RBRACE, CHECK_OK);
int end_pos = scanner()->location().end_pos;
if (constructor == NULL) {
constructor = DefaultConstructor(name, has_extends, block_scope, pos,
end_pos, block_scope->language_mode());
}
// Note that we do not finalize this block scope because it is
// used as a sentinel value indicating an anonymous class.
block_scope->set_end_position(end_pos);
if (name != NULL) {
DCHECK_NOT_NULL(proxy);
proxy->var()->set_initializer_position(end_pos);
}
return factory()->NewClassLiteral(block_scope, proxy, extends, constructor,
properties, pos, end_pos);
}
Expression* Parser::ParseV8Intrinsic(bool* ok) {
// CallRuntime ::
// '%' Identifier Arguments
int pos = peek_position();
Expect(Token::MOD, CHECK_OK);
// Allow "eval" or "arguments" for backward compatibility.
const AstRawString* name = ParseIdentifier(kAllowRestrictedIdentifiers,
CHECK_OK);
Scanner::Location spread_pos;
ExpressionClassifier classifier(this);
ZoneList<Expression*>* args =
ParseArguments(&spread_pos, &classifier, CHECK_OK);
DCHECK(!spread_pos.IsValid());
if (extension_ != NULL) {
// The extension structures are only accessible while parsing the
// very first time not when reparsing because of lazy compilation.
scope_->DeclarationScope()->ForceEagerCompilation();
}
const Runtime::Function* function = Runtime::FunctionForName(name->string());
if (function != NULL) {
// Check for possible name clash.
DCHECK_EQ(Context::kNotFound,
Context::IntrinsicIndexForName(name->string()));
// Check for built-in IS_VAR macro.
if (function->function_id == Runtime::kIS_VAR) {
DCHECK_EQ(Runtime::RUNTIME, function->intrinsic_type);
// %IS_VAR(x) evaluates to x if x is a variable,
// leads to a parse error otherwise. Could be implemented as an
// inline function %_IS_VAR(x) to eliminate this special case.
if (args->length() == 1 && args->at(0)->AsVariableProxy() != NULL) {
return args->at(0);
} else {
ReportMessage(MessageTemplate::kNotIsvar);
*ok = false;
return NULL;
}
}
// Check that the expected number of arguments are being passed.
if (function->nargs != -1 && function->nargs != args->length()) {
ReportMessage(MessageTemplate::kRuntimeWrongNumArgs);
*ok = false;
return NULL;
}
return factory()->NewCallRuntime(function, args, pos);
}
int context_index = Context::IntrinsicIndexForName(name->string());
// Check that the function is defined.
if (context_index == Context::kNotFound) {
ParserTraits::ReportMessage(MessageTemplate::kNotDefined, name);
*ok = false;
return NULL;
}
return factory()->NewCallRuntime(context_index, args, pos);
}
Literal* Parser::GetLiteralUndefined(int position) {
return factory()->NewUndefinedLiteral(position);
}
void Parser::CheckConflictingVarDeclarations(Scope* scope, bool* ok) {
Declaration* decl = scope->CheckConflictingVarDeclarations();
if (decl != NULL) {
// In ES6, conflicting variable bindings are early errors.
const AstRawString* name = decl->proxy()->raw_name();
int position = decl->proxy()->position();
Scanner::Location location = position == RelocInfo::kNoPosition
? Scanner::Location::invalid()
: Scanner::Location(position, position + 1);
ParserTraits::ReportMessageAt(location, MessageTemplate::kVarRedeclaration,
name);
*ok = false;
}
}
void Parser::InsertShadowingVarBindingInitializers(Block* inner_block) {
// For each var-binding that shadows a parameter, insert an assignment
// initializing the variable with the parameter.
Scope* inner_scope = inner_block->scope();
DCHECK(inner_scope->is_declaration_scope());
Scope* function_scope = inner_scope->outer_scope();
DCHECK(function_scope->is_function_scope());
ZoneList<Declaration*>* decls = inner_scope->declarations();
for (int i = 0; i < decls->length(); ++i) {
Declaration* decl = decls->at(i);
if (decl->mode() != VAR || !decl->IsVariableDeclaration()) continue;
const AstRawString* name = decl->proxy()->raw_name();
Variable* parameter = function_scope->LookupLocal(name);
if (parameter == nullptr) continue;
VariableProxy* to = inner_scope->NewUnresolved(factory(), name);
VariableProxy* from = factory()->NewVariableProxy(parameter);
Expression* assignment = factory()->NewAssignment(
Token::ASSIGN, to, from, RelocInfo::kNoPosition);
Statement* statement = factory()->NewExpressionStatement(
assignment, RelocInfo::kNoPosition);
inner_block->statements()->InsertAt(0, statement, zone());
}
}
void Parser::InsertSloppyBlockFunctionVarBindings(Scope* scope, bool* ok) {
// For each variable which is used as a function declaration in a sloppy
// block,
DCHECK(scope->is_declaration_scope());
SloppyBlockFunctionMap* map = scope->sloppy_block_function_map();
for (ZoneHashMap::Entry* p = map->Start(); p != nullptr; p = map->Next(p)) {
AstRawString* name = static_cast<AstRawString*>(p->key);
// If the variable wouldn't conflict with a lexical declaration,
Variable* var = scope->LookupLocal(name);
if (var == nullptr || !IsLexicalVariableMode(var->mode())) {
// Declare a var-style binding for the function in the outer scope
VariableProxy* proxy = scope->NewUnresolved(factory(), name);
Declaration* declaration = factory()->NewVariableDeclaration(
proxy, VAR, scope, RelocInfo::kNoPosition);
Declare(declaration, DeclarationDescriptor::NORMAL, true, ok, scope);
DCHECK(ok); // Based on the preceding check, this should not fail
if (!ok) return;
// Write in assignments to var for each block-scoped function declaration
auto delegates = static_cast<SloppyBlockFunctionMap::Vector*>(p->value);
for (SloppyBlockFunctionStatement* delegate : *delegates) {
// Read from the local lexical scope and write to the function scope
VariableProxy* to = scope->NewUnresolved(factory(), name);
VariableProxy* from = delegate->scope()->NewUnresolved(factory(), name);
Expression* assignment = factory()->NewAssignment(
Token::ASSIGN, to, from, RelocInfo::kNoPosition);
Statement* statement = factory()->NewExpressionStatement(
assignment, RelocInfo::kNoPosition);
delegate->set_statement(statement);
}
}
}
}
// ----------------------------------------------------------------------------
// Parser support
bool Parser::TargetStackContainsLabel(const AstRawString* label) {
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
if (ContainsLabel(t->statement()->labels(), label)) return true;
}
return false;
}
BreakableStatement* Parser::LookupBreakTarget(const AstRawString* label,
bool* ok) {
bool anonymous = label == NULL;
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
BreakableStatement* stat = t->statement();
if ((anonymous && stat->is_target_for_anonymous()) ||
(!anonymous && ContainsLabel(stat->labels(), label))) {
return stat;
}
}
return NULL;
}
IterationStatement* Parser::LookupContinueTarget(const AstRawString* label,
bool* ok) {
bool anonymous = label == NULL;
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
IterationStatement* stat = t->statement()->AsIterationStatement();
if (stat == NULL) continue;
DCHECK(stat->is_target_for_anonymous());
if (anonymous || ContainsLabel(stat->labels(), label)) {
return stat;
}
}
return NULL;
}
void Parser::HandleSourceURLComments(Isolate* isolate, Handle<Script> script) {
if (scanner_.source_url()->length() > 0) {
Handle<String> source_url = scanner_.source_url()->Internalize(isolate);
script->set_source_url(*source_url);
}
if (scanner_.source_mapping_url()->length() > 0) {
Handle<String> source_mapping_url =
scanner_.source_mapping_url()->Internalize(isolate);
script->set_source_mapping_url(*source_mapping_url);
}
}
void Parser::Internalize(Isolate* isolate, Handle<Script> script, bool error) {
// Internalize strings.
ast_value_factory()->Internalize(isolate);
// Error processing.
if (error) {
if (stack_overflow()) {
isolate->StackOverflow();
} else {
DCHECK(pending_error_handler_.has_pending_error());
pending_error_handler_.ThrowPendingError(isolate, script);
}
}
// Move statistics to Isolate.
for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
++feature) {
for (int i = 0; i < use_counts_[feature]; ++i) {
isolate->CountUsage(v8::Isolate::UseCounterFeature(feature));
}
}
if (scanner_.FoundHtmlComment()) {
isolate->CountUsage(v8::Isolate::kHtmlComment);
if (script->line_offset() == 0 && script->column_offset() == 0) {
isolate->CountUsage(v8::Isolate::kHtmlCommentInExternalScript);
}
}
isolate->counters()->total_preparse_skipped()->Increment(
total_preparse_skipped_);
}
// ----------------------------------------------------------------------------
// The Parser interface.
bool Parser::ParseStatic(ParseInfo* info) {
Parser parser(info);
if (parser.Parse(info)) {
info->set_language_mode(info->literal()->language_mode());
return true;
}
return false;
}
bool Parser::Parse(ParseInfo* info) {
DCHECK(info->literal() == NULL);
FunctionLiteral* result = NULL;
// Ok to use Isolate here; this function is only called in the main thread.
DCHECK(parsing_on_main_thread_);
Isolate* isolate = info->isolate();
pre_parse_timer_ = isolate->counters()->pre_parse();
if (FLAG_trace_parse || allow_natives() || extension_ != NULL) {
// If intrinsics are allowed, the Parser cannot operate independent of the
// V8 heap because of Runtime. Tell the string table to internalize strings
// and values right after they're created.
ast_value_factory()->Internalize(isolate);
}
if (info->is_lazy()) {
DCHECK(!info->is_eval());
if (info->shared_info()->is_function()) {
result = ParseLazy(isolate, info);
} else {
result = ParseProgram(isolate, info);
}
} else {
SetCachedData(info);
result = ParseProgram(isolate, info);
}
info->set_literal(result);
Internalize(isolate, info->script(), result == NULL);
DCHECK(ast_value_factory()->IsInternalized());
return (result != NULL);
}
void Parser::ParseOnBackground(ParseInfo* info) {
parsing_on_main_thread_ = false;
DCHECK(info->literal() == NULL);
FunctionLiteral* result = NULL;
fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
CompleteParserRecorder recorder;
if (produce_cached_parse_data()) log_ = &recorder;
DCHECK(info->source_stream() != NULL);
ExternalStreamingStream stream(info->source_stream(),
info->source_stream_encoding());
scanner_.Initialize(&stream);
DCHECK(info->context().is_null() || info->context()->IsNativeContext());
// When streaming, we don't know the length of the source until we have parsed
// it. The raw data can be UTF-8, so we wouldn't know the source length until
// we have decoded it anyway even if we knew the raw data length (which we
// don't). We work around this by storing all the scopes which need their end
// position set at the end of the script (the top scope and possible eval
// scopes) and set their end position after we know the script length.
result = DoParseProgram(info);
info->set_literal(result);
// We cannot internalize on a background thread; a foreground task will take
// care of calling Parser::Internalize just before compilation.
if (produce_cached_parse_data()) {
if (result != NULL) *info->cached_data() = recorder.GetScriptData();
log_ = NULL;
}
}
ParserTraits::TemplateLiteralState Parser::OpenTemplateLiteral(int pos) {
return new (zone()) ParserTraits::TemplateLiteral(zone(), pos);
}
void Parser::AddTemplateSpan(TemplateLiteralState* state, bool tail) {
int pos = scanner()->location().beg_pos;
int end = scanner()->location().end_pos - (tail ? 1 : 2);
const AstRawString* tv = scanner()->CurrentSymbol(ast_value_factory());
const AstRawString* trv = scanner()->CurrentRawSymbol(ast_value_factory());
Literal* cooked = factory()->NewStringLiteral(tv, pos);
Literal* raw = factory()->NewStringLiteral(trv, pos);
(*state)->AddTemplateSpan(cooked, raw, end, zone());
}
void Parser::AddTemplateExpression(TemplateLiteralState* state,
Expression* expression) {
(*state)->AddExpression(expression, zone());
}
Expression* Parser::CloseTemplateLiteral(TemplateLiteralState* state, int start,
Expression* tag) {
TemplateLiteral* lit = *state;
int pos = lit->position();
const ZoneList<Expression*>* cooked_strings = lit->cooked();
const ZoneList<Expression*>* raw_strings = lit->raw();
const ZoneList<Expression*>* expressions = lit->expressions();
DCHECK_EQ(cooked_strings->length(), raw_strings->length());
DCHECK_EQ(cooked_strings->length(), expressions->length() + 1);
if (!tag) {
// Build tree of BinaryOps to simplify code-generation
Expression* expr = cooked_strings->at(0);
int i = 0;
while (i < expressions->length()) {
Expression* sub = expressions->at(i++);
Expression* cooked_str = cooked_strings->at(i);
// Let middle be ToString(sub).
ZoneList<Expression*>* args =
new (zone()) ZoneList<Expression*>(1, zone());
args->Add(sub, zone());
Expression* middle = factory()->NewCallRuntime(Runtime::kInlineToString,
args, sub->position());
expr = factory()->NewBinaryOperation(
Token::ADD, factory()->NewBinaryOperation(
Token::ADD, expr, middle, expr->position()),
cooked_str, sub->position());
}
return expr;
} else {
uint32_t hash = ComputeTemplateLiteralHash(lit);
int cooked_idx = function_state_->NextMaterializedLiteralIndex();
int raw_idx = function_state_->NextMaterializedLiteralIndex();
// $getTemplateCallSite
ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(4, zone());
args->Add(factory()->NewArrayLiteral(
const_cast<ZoneList<Expression*>*>(cooked_strings),
cooked_idx, pos),
zone());
args->Add(
factory()->NewArrayLiteral(
const_cast<ZoneList<Expression*>*>(raw_strings), raw_idx, pos),
zone());
// Ensure hash is suitable as a Smi value
Smi* hash_obj = Smi::cast(Internals::IntToSmi(static_cast<int>(hash)));
args->Add(factory()->NewSmiLiteral(hash_obj->value(), pos), zone());
Expression* call_site = factory()->NewCallRuntime(
Context::GET_TEMPLATE_CALL_SITE_INDEX, args, start);
// Call TagFn
ZoneList<Expression*>* call_args =
new (zone()) ZoneList<Expression*>(expressions->length() + 1, zone());
call_args->Add(call_site, zone());
call_args->AddAll(*expressions, zone());
return factory()->NewCall(tag, call_args, pos);
}
}
uint32_t Parser::ComputeTemplateLiteralHash(const TemplateLiteral* lit) {
const ZoneList<Expression*>* raw_strings = lit->raw();
int total = raw_strings->length();
DCHECK(total);
uint32_t running_hash = 0;
for (int index = 0; index < total; ++index) {
if (index) {
running_hash = StringHasher::ComputeRunningHashOneByte(
running_hash, "${}", 3);
}
const AstRawString* raw_string =
raw_strings->at(index)->AsLiteral()->raw_value()->AsString();
if (raw_string->is_one_byte()) {
const char* data = reinterpret_cast<const char*>(raw_string->raw_data());
running_hash = StringHasher::ComputeRunningHashOneByte(
running_hash, data, raw_string->length());
} else {
const uc16* data = reinterpret_cast<const uc16*>(raw_string->raw_data());
running_hash = StringHasher::ComputeRunningHash(running_hash, data,
raw_string->length());
}
}
return running_hash;
}
ZoneList<v8::internal::Expression*>* Parser::PrepareSpreadArguments(
ZoneList<v8::internal::Expression*>* list) {
ZoneList<v8::internal::Expression*>* args =
new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
if (list->length() == 1) {
// Spread-call with single spread argument produces an InternalArray
// containing the values from the array.
//
// Function is called or constructed with the produced array of arguments
//
// EG: Apply(Func, Spread(spread0))
ZoneList<Expression*>* spread_list =
new (zone()) ZoneList<Expression*>(0, zone());
spread_list->Add(list->at(0)->AsSpread()->expression(), zone());
args->Add(factory()->NewCallRuntime(Context::SPREAD_ITERABLE_INDEX,
spread_list, RelocInfo::kNoPosition),
zone());
return args;
} else {
// Spread-call with multiple arguments produces array literals for each
// sequences of unspread arguments, and converts each spread iterable to
// an Internal array. Finally, all of these produced arrays are flattened
// into a single InternalArray, containing the arguments for the call.
//
// EG: Apply(Func, Flatten([unspread0, unspread1], Spread(spread0),
// Spread(spread1), [unspread2, unspread3]))
int i = 0;
int n = list->length();
while (i < n) {
if (!list->at(i)->IsSpread()) {
ZoneList<v8::internal::Expression*>* unspread =
new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
// Push array of unspread parameters
while (i < n && !list->at(i)->IsSpread()) {
unspread->Add(list->at(i++), zone());
}
int literal_index = function_state_->NextMaterializedLiteralIndex();
args->Add(factory()->NewArrayLiteral(unspread, literal_index,
RelocInfo::kNoPosition),
zone());
if (i == n) break;
}
// Push eagerly spread argument
ZoneList<v8::internal::Expression*>* spread_list =
new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
spread_list->Add(list->at(i++)->AsSpread()->expression(), zone());
args->Add(factory()->NewCallRuntime(Context::SPREAD_ITERABLE_INDEX,
spread_list, RelocInfo::kNoPosition),
zone());
}
list = new (zone()) ZoneList<v8::internal::Expression*>(1, zone());
list->Add(factory()->NewCallRuntime(Context::SPREAD_ARGUMENTS_INDEX, args,
RelocInfo::kNoPosition),
zone());
return list;
}
UNREACHABLE();
}
Expression* Parser::SpreadCall(Expression* function,
ZoneList<v8::internal::Expression*>* args,
int pos) {
if (function->IsSuperCallReference()) {
// Super calls
// $super_constructor = %_GetSuperConstructor(<this-function>)
// %reflect_construct($super_constructor, args, new.target)
ZoneList<Expression*>* tmp = new (zone()) ZoneList<Expression*>(1, zone());
tmp->Add(function->AsSuperCallReference()->this_function_var(), zone());
Expression* super_constructor = factory()->NewCallRuntime(
Runtime::kInlineGetSuperConstructor, tmp, pos);
args->InsertAt(0, super_constructor, zone());
args->Add(function->AsSuperCallReference()->new_target_var(), zone());
return factory()->NewCallRuntime(Context::REFLECT_CONSTRUCT_INDEX, args,
pos);
} else {
if (function->IsProperty()) {
// Method calls
if (function->AsProperty()->IsSuperAccess()) {
Expression* home =
ThisExpression(scope_, factory(), RelocInfo::kNoPosition);
args->InsertAt(0, function, zone());
args->InsertAt(1, home, zone());
} else {
Variable* temp =
scope_->NewTemporary(ast_value_factory()->empty_string());
VariableProxy* obj = factory()->NewVariableProxy(temp);
Assignment* assign_obj = factory()->NewAssignment(
Token::ASSIGN, obj, function->AsProperty()->obj(),
RelocInfo::kNoPosition);
function = factory()->NewProperty(
assign_obj, function->AsProperty()->key(), RelocInfo::kNoPosition);
args->InsertAt(0, function, zone());
obj = factory()->NewVariableProxy(temp);
args->InsertAt(1, obj, zone());
}
} else {
// Non-method calls
args->InsertAt(0, function, zone());
args->InsertAt(1, factory()->NewUndefinedLiteral(RelocInfo::kNoPosition),
zone());
}
return factory()->NewCallRuntime(Context::REFLECT_APPLY_INDEX, args, pos);
}
}
Expression* Parser::SpreadCallNew(Expression* function,
ZoneList<v8::internal::Expression*>* args,
int pos) {
args->InsertAt(0, function, zone());
return factory()->NewCallRuntime(Context::REFLECT_CONSTRUCT_INDEX, args, pos);
}
void Parser::SetLanguageMode(Scope* scope, LanguageMode mode) {
v8::Isolate::UseCounterFeature feature;
if (is_sloppy(mode))
feature = v8::Isolate::kSloppyMode;
else if (is_strict(mode))
feature = v8::Isolate::kStrictMode;
else
UNREACHABLE();
++use_counts_[feature];
scope->SetLanguageMode(mode);
}
void Parser::RaiseLanguageMode(LanguageMode mode) {
LanguageMode old = scope_->language_mode();
SetLanguageMode(scope_, old > mode ? old : mode);
}
void Parser::MarkCollectedTailCallExpressions() {
const ZoneList<Expression*>& tail_call_expressions =
function_state_->tail_call_expressions().expressions();
for (int i = 0; i < tail_call_expressions.length(); ++i) {
Expression* expression = tail_call_expressions[i];
// If only FLAG_harmony_explicit_tailcalls is enabled then expression
// must be a Call expression.
DCHECK(FLAG_harmony_tailcalls || !FLAG_harmony_explicit_tailcalls ||
expression->IsCall());
MarkTailPosition(expression);
}
}
Expression* ParserTraits::ExpressionListToExpression(
ZoneList<Expression*>* args) {
AstNodeFactory* factory = parser_->factory();
Expression* expr = args->at(0);
for (int i = 1; i < args->length(); ++i) {
expr = factory->NewBinaryOperation(Token::COMMA, expr, args->at(i),
expr->position());
}
return expr;
}
void ParserTraits::RewriteDestructuringAssignments() {
parser_->RewriteDestructuringAssignments();
}
Expression* ParserTraits::RewriteExponentiation(Expression* left,
Expression* right, int pos) {
return parser_->RewriteExponentiation(left, right, pos);
}
Expression* ParserTraits::RewriteAssignExponentiation(Expression* left,
Expression* right,
int pos) {
return parser_->RewriteAssignExponentiation(left, right, pos);
}
void ParserTraits::RewriteNonPattern(Type::ExpressionClassifier* classifier,
bool* ok) {
parser_->RewriteNonPattern(classifier, ok);
}
Expression* ParserTraits::RewriteAwaitExpression(Expression* value,
int await_pos) {
// yield %AsyncFunctionAwait(.generator_object, <operand>)
Variable* generator_object_variable =
parser_->function_state_->generator_object_variable();
// If generator_object_variable is null,
if (!generator_object_variable) return value;
auto factory = parser_->factory();
const int nopos = RelocInfo::kNoPosition;
Variable* temp_var = parser_->scope_->NewTemporary(
parser_->ast_value_factory()->empty_string());
VariableProxy* temp_proxy = factory->NewVariableProxy(temp_var);
Block* do_block = factory->NewBlock(nullptr, 2, false, nopos);
// Wrap value evaluation to provide a break location.
Expression* value_assignment =
factory->NewAssignment(Token::ASSIGN, temp_proxy, value, nopos);
do_block->statements()->Add(
factory->NewExpressionStatement(value_assignment, value->position()),
zone());
ZoneList<Expression*>* async_function_await_args =
new (zone()) ZoneList<Expression*>(2, zone());
Expression* generator_object =
factory->NewVariableProxy(generator_object_variable);
async_function_await_args->Add(generator_object, zone());
async_function_await_args->Add(temp_proxy, zone());
Expression* async_function_await = parser_->factory()->NewCallRuntime(
Context::ASYNC_FUNCTION_AWAIT_INDEX, async_function_await_args, nopos);
// Wrap await to provide a break location between value evaluation and yield.
Expression* await_assignment = factory->NewAssignment(
Token::ASSIGN, temp_proxy, async_function_await, nopos);
do_block->statements()->Add(
factory->NewExpressionStatement(await_assignment, await_pos), zone());
Expression* do_expr = factory->NewDoExpression(do_block, temp_var, nopos);
generator_object = factory->NewVariableProxy(generator_object_variable);
return factory->NewYield(generator_object, do_expr, nopos);
}
ZoneList<Expression*>* ParserTraits::GetNonPatternList() const {
return parser_->function_state_->non_patterns_to_rewrite();
}
ZoneList<typename ParserTraits::Type::ExpressionClassifier::Error>*
ParserTraits::GetReportedErrorList() const {
return parser_->function_state_->GetReportedErrorList();
}
Zone* ParserTraits::zone() const {
return parser_->function_state_->scope()->zone();
}
class NonPatternRewriter : public AstExpressionRewriter {
public:
NonPatternRewriter(uintptr_t stack_limit, Parser* parser)
: AstExpressionRewriter(stack_limit), parser_(parser) {}
~NonPatternRewriter() override {}
private:
bool RewriteExpression(Expression* expr) override {
if (expr->IsRewritableExpression()) return true;
// Rewrite only what could have been a pattern but is not.
if (expr->IsArrayLiteral()) {
// Spread rewriting in array literals.
ArrayLiteral* lit = expr->AsArrayLiteral();
VisitExpressions(lit->values());
replacement_ = parser_->RewriteSpreads(lit);
return false;
}
if (expr->IsObjectLiteral()) {
return true;
}
if (expr->IsBinaryOperation() &&
expr->AsBinaryOperation()->op() == Token::COMMA) {
return true;
}
// Everything else does not need rewriting.
return false;
}
void VisitObjectLiteralProperty(ObjectLiteralProperty* property) override {
if (property == nullptr) return;
// Do not rewrite (computed) key expressions
AST_REWRITE_PROPERTY(Expression, property, value);
}
Parser* parser_;
};
void Parser::RewriteNonPattern(ExpressionClassifier* classifier, bool* ok) {
ValidateExpression(classifier, ok);
if (!*ok) return;
auto non_patterns_to_rewrite = function_state_->non_patterns_to_rewrite();
int begin = classifier->GetNonPatternBegin();
int end = non_patterns_to_rewrite->length();
if (begin < end) {
NonPatternRewriter rewriter(stack_limit_, this);
for (int i = begin; i < end; i++) {
DCHECK(non_patterns_to_rewrite->at(i)->IsRewritableExpression());
rewriter.Rewrite(non_patterns_to_rewrite->at(i));
}
non_patterns_to_rewrite->Rewind(begin);
}
}
void Parser::RewriteDestructuringAssignments() {
const auto& assignments =
function_state_->destructuring_assignments_to_rewrite();
for (int i = assignments.length() - 1; i >= 0; --i) {
// Rewrite list in reverse, so that nested assignment patterns are rewritten
// correctly.
const DestructuringAssignment& pair = assignments.at(i);
RewritableExpression* to_rewrite =
pair.assignment->AsRewritableExpression();
DCHECK_NOT_NULL(to_rewrite);
if (!to_rewrite->is_rewritten()) {
PatternRewriter::RewriteDestructuringAssignment(this, to_rewrite,
pair.scope);
}
}
}
Expression* Parser::RewriteExponentiation(Expression* left, Expression* right,
int pos) {
ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(2, zone());
args->Add(left, zone());
args->Add(right, zone());
return factory()->NewCallRuntime(Context::MATH_POW_METHOD_INDEX, args, pos);
}
Expression* Parser::RewriteAssignExponentiation(Expression* left,
Expression* right, int pos) {
ZoneList<Expression*>* args = new (zone()) ZoneList<Expression*>(2, zone());
if (left->IsVariableProxy()) {
VariableProxy* lhs = left->AsVariableProxy();
Expression* result;
DCHECK_NOT_NULL(lhs->raw_name());
result =
this->ExpressionFromIdentifier(lhs->raw_name(), lhs->position(),
lhs->end_position(), scope_, factory());
args->Add(left, zone());
args->Add(right, zone());
Expression* call =
factory()->NewCallRuntime(Context::MATH_POW_METHOD_INDEX, args, pos);
return factory()->NewAssignment(Token::ASSIGN, result, call, pos);
} else if (left->IsProperty()) {
Property* prop = left->AsProperty();
auto temp_obj = scope_->NewTemporary(ast_value_factory()->empty_string());
auto temp_key = scope_->NewTemporary(ast_value_factory()->empty_string());
Expression* assign_obj = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(temp_obj), prop->obj(),
RelocInfo::kNoPosition);
Expression* assign_key = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(temp_key), prop->key(),
RelocInfo::kNoPosition);
args->Add(factory()->NewProperty(factory()->NewVariableProxy(temp_obj),
factory()->NewVariableProxy(temp_key),
left->position()),
zone());
args->Add(right, zone());
Expression* call =
factory()->NewCallRuntime(Context::MATH_POW_METHOD_INDEX, args, pos);
Expression* target = factory()->NewProperty(
factory()->NewVariableProxy(temp_obj),
factory()->NewVariableProxy(temp_key), RelocInfo::kNoPosition);
Expression* assign =
factory()->NewAssignment(Token::ASSIGN, target, call, pos);
return factory()->NewBinaryOperation(
Token::COMMA, assign_obj,
factory()->NewBinaryOperation(Token::COMMA, assign_key, assign, pos),
pos);
}
UNREACHABLE();
return nullptr;
}
Expression* Parser::RewriteSpreads(ArrayLiteral* lit) {
// Array literals containing spreads are rewritten using do expressions, e.g.
// [1, 2, 3, ...x, 4, ...y, 5]
// is roughly rewritten as:
// do {
// $R = [1, 2, 3];
// for ($i of x) %AppendElement($R, $i);
// %AppendElement($R, 4);
// for ($j of y) %AppendElement($R, $j);
// %AppendElement($R, 5);
// $R
// }
// where $R, $i and $j are fresh temporary variables.
ZoneList<Expression*>::iterator s = lit->FirstSpread();
if (s == lit->EndValue()) return nullptr; // no spread, no rewriting...
Variable* result =
scope_->NewTemporary(ast_value_factory()->dot_result_string());
// NOTE: The value assigned to R is the whole original array literal,
// spreads included. This will be fixed before the rewritten AST is returned.
// $R = lit
Expression* init_result =
factory()->NewAssignment(Token::INIT, factory()->NewVariableProxy(result),
lit, RelocInfo::kNoPosition);
Block* do_block =
factory()->NewBlock(nullptr, 16, false, RelocInfo::kNoPosition);
do_block->statements()->Add(
factory()->NewExpressionStatement(init_result, RelocInfo::kNoPosition),
zone());
// Traverse the array literal starting from the first spread.
while (s != lit->EndValue()) {
Expression* value = *s++;
Spread* spread = value->AsSpread();
if (spread == nullptr) {
// If the element is not a spread, we're adding a single:
// %AppendElement($R, value)
ZoneList<Expression*>* append_element_args = NewExpressionList(2, zone());
append_element_args->Add(factory()->NewVariableProxy(result), zone());
append_element_args->Add(value, zone());
do_block->statements()->Add(
factory()->NewExpressionStatement(
factory()->NewCallRuntime(Runtime::kAppendElement,
append_element_args,
RelocInfo::kNoPosition),
RelocInfo::kNoPosition),
zone());
} else {
// If it's a spread, we're adding a for/of loop iterating through it.
Variable* each =
scope_->NewTemporary(ast_value_factory()->dot_for_string());
Expression* subject = spread->expression();
// %AppendElement($R, each)
Statement* append_body;
{
ZoneList<Expression*>* append_element_args =
NewExpressionList(2, zone());
append_element_args->Add(factory()->NewVariableProxy(result), zone());
append_element_args->Add(factory()->NewVariableProxy(each), zone());
append_body = factory()->NewExpressionStatement(
factory()->NewCallRuntime(Runtime::kAppendElement,
append_element_args,
RelocInfo::kNoPosition),
RelocInfo::kNoPosition);
}
// for (each of spread) %AppendElement($R, each)
ForEachStatement* loop = factory()->NewForEachStatement(
ForEachStatement::ITERATE, nullptr, RelocInfo::kNoPosition);
InitializeForOfStatement(loop->AsForOfStatement(),
factory()->NewVariableProxy(each), subject,
append_body);
do_block->statements()->Add(loop, zone());
}
}
// Now, rewind the original array literal to truncate everything from the
// first spread (included) until the end. This fixes $R's initialization.
lit->RewindSpreads();
return factory()->NewDoExpression(do_block, result, lit->position());
}
void ParserTraits::QueueDestructuringAssignmentForRewriting(Expression* expr) {
DCHECK(expr->IsRewritableExpression());
parser_->function_state_->AddDestructuringAssignment(
Parser::DestructuringAssignment(expr, parser_->scope_));
}
void ParserTraits::QueueNonPatternForRewriting(Expression* expr, bool* ok) {
DCHECK(expr->IsRewritableExpression());
parser_->function_state_->AddNonPatternForRewriting(expr, ok);
}
void ParserTraits::SetFunctionNameFromPropertyName(
ObjectLiteralProperty* property, const AstRawString* name) {
Expression* value = property->value();
// Computed name setting must happen at runtime.
if (property->is_computed_name()) return;
// Getter and setter names are handled here because their names
// change in ES2015, even though they are not anonymous.
auto function = value->AsFunctionLiteral();
if (function != nullptr) {
bool is_getter = property->kind() == ObjectLiteralProperty::GETTER;
bool is_setter = property->kind() == ObjectLiteralProperty::SETTER;
if (is_getter || is_setter) {
DCHECK_NOT_NULL(name);
const AstRawString* prefix =
is_getter ? parser_->ast_value_factory()->get_space_string()
: parser_->ast_value_factory()->set_space_string();
function->set_raw_name(
parser_->ast_value_factory()->NewConsString(prefix, name));
return;
}
}
if (!value->IsAnonymousFunctionDefinition()) return;
DCHECK_NOT_NULL(name);
// Ignore "__proto__" as a name when it's being used to set the [[Prototype]]
// of an object literal.
if (property->kind() == ObjectLiteralProperty::PROTOTYPE) return;
if (function != nullptr) {
function->set_raw_name(name);
DCHECK_EQ(ObjectLiteralProperty::COMPUTED, property->kind());
} else {
DCHECK(value->IsClassLiteral());
DCHECK_EQ(ObjectLiteralProperty::COMPUTED, property->kind());
value->AsClassLiteral()->constructor()->set_raw_name(name);
}
}
void ParserTraits::SetFunctionNameFromIdentifierRef(Expression* value,
Expression* identifier) {
if (!value->IsAnonymousFunctionDefinition()) return;
if (!identifier->IsVariableProxy()) return;
auto name = identifier->AsVariableProxy()->raw_name();
DCHECK_NOT_NULL(name);
auto function = value->AsFunctionLiteral();
if (function != nullptr) {
function->set_raw_name(name);
} else {
DCHECK(value->IsClassLiteral());
value->AsClassLiteral()->constructor()->set_raw_name(name);
}
}
// Desugaring of yield*
// ====================
//
// With the help of do-expressions and function.sent, we desugar yield* into a
// loop containing a "raw" yield (a yield that doesn't wrap an iterator result
// object around its argument). Concretely, "yield* iterable" turns into
// roughly the following code:
//
// do {
// const kNext = 0;
// const kReturn = 1;
// const kThrow = 2;
//
// let input = function.sent;
// let mode = kNext;
// let output = undefined;
//
// let iterator = iterable[Symbol.iterator]();
// if (!IS_RECEIVER(iterator)) throw MakeTypeError(kSymbolIteratorInvalid);
//
// while (true) {
// // From the generator to the iterator:
// // Forward input according to resume mode and obtain output.
// switch (mode) {
// case kNext:
// output = iterator.next(input);
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
// break;
// case kReturn:
// IteratorClose(iterator, input, output); // See below.
// break;
// case kThrow:
// let iteratorThrow = iterator.throw;
// if (IS_NULL_OR_UNDEFINED(iteratorThrow)) {
// IteratorClose(iterator); // See below.
// throw MakeTypeError(kThrowMethodMissing);
// }
// output = %_Call(iteratorThrow, iterator, input);
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
// break;
// }
// if (output.done) break;
//
// // From the generator to its user:
// // Forward output, receive new input, and determine resume mode.
// mode = kReturn;
// try {
// try {
// RawYield(output); // See explanation above.
// mode = kNext;
// } catch (error) {
// mode = kThrow;
// }
// } finally {
// input = function.sent;
// continue;
// }
// }
//
// output.value;
// }
//
// IteratorClose(iterator) expands to the following:
//
// let iteratorReturn = iterator.return;
// if (IS_NULL_OR_UNDEFINED(iteratorReturn)) return;
// let output = %_Call(iteratorReturn, iterator);
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
//
// IteratorClose(iterator, input, output) expands to the following:
//
// let iteratorReturn = iterator.return;
// if (IS_NULL_OR_UNDEFINED(iteratorReturn)) return input;
// output = %_Call(iteratorReturn, iterator, input);
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
Expression* ParserTraits::RewriteYieldStar(
Expression* generator, Expression* iterable, int pos) {
const int nopos = RelocInfo::kNoPosition;
auto factory = parser_->factory();
auto avfactory = parser_->ast_value_factory();
auto scope = parser_->scope_;
auto zone = parser_->zone();
// Forward definition for break/continue statements.
WhileStatement* loop = factory->NewWhileStatement(nullptr, nopos);
// let input = undefined;
Variable* var_input = scope->NewTemporary(avfactory->empty_string());
Statement* initialize_input;
{
Expression* input_proxy = factory->NewVariableProxy(var_input);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, input_proxy, factory->NewUndefinedLiteral(nopos), nopos);
initialize_input = factory->NewExpressionStatement(assignment, nopos);
}
// let mode = kNext;
Variable* var_mode = scope->NewTemporary(avfactory->empty_string());
Statement* initialize_mode;
{
Expression* mode_proxy = factory->NewVariableProxy(var_mode);
Expression* knext = factory->NewSmiLiteral(JSGeneratorObject::kNext, nopos);
Expression* assignment =
factory->NewAssignment(Token::ASSIGN, mode_proxy, knext, nopos);
initialize_mode = factory->NewExpressionStatement(assignment, nopos);
}
// let output = undefined;
Variable* var_output = scope->NewTemporary(avfactory->empty_string());
Statement* initialize_output;
{
Expression* output_proxy = factory->NewVariableProxy(var_output);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, output_proxy, factory->NewUndefinedLiteral(nopos),
nopos);
initialize_output = factory->NewExpressionStatement(assignment, nopos);
}
// let iterator = iterable[Symbol.iterator];
Variable* var_iterator = scope->NewTemporary(avfactory->empty_string());
Statement* get_iterator;
{
Expression* iterator = GetIterator(iterable, factory, nopos);
Expression* iterator_proxy = factory->NewVariableProxy(var_iterator);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, iterator_proxy, iterator, nopos);
get_iterator = factory->NewExpressionStatement(assignment, nopos);
}
// if (!IS_RECEIVER(iterator)) throw MakeTypeError(kSymbolIteratorInvalid);
Statement* validate_iterator;
{
Expression* is_receiver_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_iterator), zone);
is_receiver_call =
factory->NewCallRuntime(Runtime::kInlineIsJSReceiver, args, nopos);
}
Statement* throw_call;
{
Expression* call = NewThrowTypeError(
MessageTemplate::kSymbolIteratorInvalid, avfactory->empty_string(),
nopos);
throw_call = factory->NewExpressionStatement(call, nopos);
}
validate_iterator = factory->NewIfStatement(
is_receiver_call, factory->NewEmptyStatement(nopos), throw_call, nopos);
}
// output = iterator.next(input);
Statement* call_next;
{
Expression* iterator_proxy = factory->NewVariableProxy(var_iterator);
Expression* literal =
factory->NewStringLiteral(avfactory->next_string(), nopos);
Expression* next_property =
factory->NewProperty(iterator_proxy, literal, nopos);
Expression* input_proxy = factory->NewVariableProxy(var_input);
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(input_proxy, zone);
Expression* call = factory->NewCall(next_property, args, nopos);
Expression* output_proxy = factory->NewVariableProxy(var_output);
Expression* assignment =
factory->NewAssignment(Token::ASSIGN, output_proxy, call, nopos);
call_next = factory->NewExpressionStatement(assignment, nopos);
}
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
Statement* validate_next_output;
{
Expression* is_receiver_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
is_receiver_call =
factory->NewCallRuntime(Runtime::kInlineIsJSReceiver, args, nopos);
}
Statement* throw_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
Expression* call = factory->NewCallRuntime(
Runtime::kThrowIteratorResultNotAnObject, args, nopos);
throw_call = factory->NewExpressionStatement(call, nopos);
}
validate_next_output = factory->NewIfStatement(
is_receiver_call, factory->NewEmptyStatement(nopos), throw_call, nopos);
}
// let iteratorThrow = iterator.throw;
Variable* var_throw = scope->NewTemporary(avfactory->empty_string());
Statement* get_throw;
{
Expression* iterator_proxy = factory->NewVariableProxy(var_iterator);
Expression* literal =
factory->NewStringLiteral(avfactory->throw_string(), nopos);
Expression* property =
factory->NewProperty(iterator_proxy, literal, nopos);
Expression* throw_proxy = factory->NewVariableProxy(var_throw);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, throw_proxy, property, nopos);
get_throw = factory->NewExpressionStatement(assignment, nopos);
}
// if (IS_NULL_OR_UNDEFINED(iteratorThrow) {
// IteratorClose(iterator);
// throw MakeTypeError(kThrowMethodMissing);
// }
Statement* check_throw;
{
Expression* condition = factory->NewCompareOperation(
Token::EQ, factory->NewVariableProxy(var_throw),
factory->NewNullLiteral(nopos), nopos);
Expression* call = NewThrowTypeError(
MessageTemplate::kThrowMethodMissing,
avfactory->empty_string(), nopos);
Statement* throw_call = factory->NewExpressionStatement(call, nopos);
Block* then = factory->NewBlock(nullptr, 4+1, false, nopos);
Variable* var_tmp = scope->NewTemporary(avfactory->empty_string());
BuildIteratorClose(then->statements(), var_iterator, Nothing<Variable*>(),
var_tmp);
then->statements()->Add(throw_call, zone);
check_throw = factory->NewIfStatement(
condition, then, factory->NewEmptyStatement(nopos), nopos);
}
// output = %_Call(iteratorThrow, iterator, input);
Statement* call_throw;
{
auto args = new (zone) ZoneList<Expression*>(3, zone);
args->Add(factory->NewVariableProxy(var_throw), zone);
args->Add(factory->NewVariableProxy(var_iterator), zone);
args->Add(factory->NewVariableProxy(var_input), zone);
Expression* call =
factory->NewCallRuntime(Runtime::kInlineCall, args, nopos);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, factory->NewVariableProxy(var_output), call, nopos);
call_throw = factory->NewExpressionStatement(assignment, nopos);
}
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
Statement* validate_throw_output;
{
Expression* is_receiver_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
is_receiver_call =
factory->NewCallRuntime(Runtime::kInlineIsJSReceiver, args, nopos);
}
Statement* throw_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
Expression* call = factory->NewCallRuntime(
Runtime::kThrowIteratorResultNotAnObject, args, nopos);
throw_call = factory->NewExpressionStatement(call, nopos);
}
validate_throw_output = factory->NewIfStatement(
is_receiver_call, factory->NewEmptyStatement(nopos), throw_call, nopos);
}
// if (output.done) break;
Statement* if_done;
{
Expression* output_proxy = factory->NewVariableProxy(var_output);
Expression* literal =
factory->NewStringLiteral(avfactory->done_string(), nopos);
Expression* property = factory->NewProperty(output_proxy, literal, nopos);
BreakStatement* break_loop = factory->NewBreakStatement(loop, nopos);
if_done = factory->NewIfStatement(
property, break_loop, factory->NewEmptyStatement(nopos), nopos);
}
// mode = kReturn;
Statement* set_mode_return;
{
Expression* mode_proxy = factory->NewVariableProxy(var_mode);
Expression* kreturn =
factory->NewSmiLiteral(JSGeneratorObject::kReturn, nopos);
Expression* assignment =
factory->NewAssignment(Token::ASSIGN, mode_proxy, kreturn, nopos);
set_mode_return = factory->NewExpressionStatement(assignment, nopos);
}
// Yield(output);
Statement* yield_output;
{
Expression* output_proxy = factory->NewVariableProxy(var_output);
Yield* yield = factory->NewYield(generator, output_proxy, nopos);
yield_output = factory->NewExpressionStatement(yield, nopos);
}
// mode = kNext;
Statement* set_mode_next;
{
Expression* mode_proxy = factory->NewVariableProxy(var_mode);
Expression* knext = factory->NewSmiLiteral(JSGeneratorObject::kNext, nopos);
Expression* assignment =
factory->NewAssignment(Token::ASSIGN, mode_proxy, knext, nopos);
set_mode_next = factory->NewExpressionStatement(assignment, nopos);
}
// mode = kThrow;
Statement* set_mode_throw;
{
Expression* mode_proxy = factory->NewVariableProxy(var_mode);
Expression* kthrow =
factory->NewSmiLiteral(JSGeneratorObject::kThrow, nopos);
Expression* assignment =
factory->NewAssignment(Token::ASSIGN, mode_proxy, kthrow, nopos);
set_mode_throw = factory->NewExpressionStatement(assignment, nopos);
}
// input = function.sent;
Statement* get_input;
{
Expression* function_sent = FunctionSentExpression(scope, factory, nopos);
Expression* input_proxy = factory->NewVariableProxy(var_input);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, input_proxy, function_sent, nopos);
get_input = factory->NewExpressionStatement(assignment, nopos);
}
// output.value;
Statement* get_value;
{
Expression* output_proxy = factory->NewVariableProxy(var_output);
Expression* literal =
factory->NewStringLiteral(avfactory->value_string(), nopos);
Expression* property = factory->NewProperty(output_proxy, literal, nopos);
get_value = factory->NewExpressionStatement(property, nopos);
}
// Now put things together.
// try { ... } catch(e) { ... }
Statement* try_catch;
{
Block* try_block = factory->NewBlock(nullptr, 2, false, nopos);
try_block->statements()->Add(yield_output, zone);
try_block->statements()->Add(set_mode_next, zone);
Block* catch_block = factory->NewBlock(nullptr, 1, false, nopos);
catch_block->statements()->Add(set_mode_throw, zone);
Scope* catch_scope = NewScope(scope, CATCH_SCOPE);
catch_scope->set_is_hidden();
const AstRawString* name = avfactory->dot_catch_string();
Variable* catch_variable =
catch_scope->DeclareLocal(name, VAR, kCreatedInitialized,
Variable::NORMAL);
try_catch = factory->NewTryCatchStatement(
try_block, catch_scope, catch_variable, catch_block, nopos);
}
// try { ... } finally { ... }
Statement* try_finally;
{
Block* try_block = factory->NewBlock(nullptr, 1, false, nopos);
try_block->statements()->Add(try_catch, zone);
Block* finally = factory->NewBlock(nullptr, 2, false, nopos);
finally->statements()->Add(get_input, zone);
finally->statements()->Add(
factory->NewContinueStatement(loop, nopos), zone);
try_finally = factory->NewTryFinallyStatement(try_block, finally, nopos);
}
// switch (mode) { ... }
SwitchStatement* switch_mode = factory->NewSwitchStatement(nullptr, nopos);
{
auto case_next = new (zone) ZoneList<Statement*>(3, zone);
case_next->Add(call_next, zone);
case_next->Add(validate_next_output, zone);
case_next->Add(factory->NewBreakStatement(switch_mode, nopos), zone);
auto case_return = new (zone) ZoneList<Statement*>(5, zone);
BuildIteratorClose(case_return, var_iterator, Just(var_input), var_output);
case_return->Add(factory->NewBreakStatement(switch_mode, nopos), zone);
auto case_throw = new (zone) ZoneList<Statement*>(5, zone);
case_throw->Add(get_throw, zone);
case_throw->Add(check_throw, zone);
case_throw->Add(call_throw, zone);
case_throw->Add(validate_throw_output, zone);
case_throw->Add(factory->NewBreakStatement(switch_mode, nopos), zone);
auto cases = new (zone) ZoneList<CaseClause*>(3, zone);
Expression* knext = factory->NewSmiLiteral(JSGeneratorObject::kNext, nopos);
Expression* kreturn =
factory->NewSmiLiteral(JSGeneratorObject::kReturn, nopos);
Expression* kthrow =
factory->NewSmiLiteral(JSGeneratorObject::kThrow, nopos);
cases->Add(factory->NewCaseClause(knext, case_next, nopos), zone);
cases->Add(factory->NewCaseClause(kreturn, case_return, nopos), zone);
cases->Add(factory->NewCaseClause(kthrow, case_throw, nopos), zone);
switch_mode->Initialize(factory->NewVariableProxy(var_mode), cases);
}
// while (true) { ... }
// Already defined earlier: WhileStatement* loop = ...
{
Block* loop_body = factory->NewBlock(nullptr, 4, false, nopos);
loop_body->statements()->Add(switch_mode, zone);
loop_body->statements()->Add(if_done, zone);
loop_body->statements()->Add(set_mode_return, zone);
loop_body->statements()->Add(try_finally, zone);
loop->Initialize(factory->NewBooleanLiteral(true, nopos), loop_body);
}
// do { ... }
DoExpression* yield_star;
{
// The rewriter needs to process the get_value statement only, hence we
// put the preceding statements into an init block.
Block* do_block_ = factory->NewBlock(nullptr, 6, true, nopos);
do_block_->statements()->Add(initialize_input, zone);
do_block_->statements()->Add(initialize_mode, zone);
do_block_->statements()->Add(initialize_output, zone);
do_block_->statements()->Add(get_iterator, zone);
do_block_->statements()->Add(validate_iterator, zone);
do_block_->statements()->Add(loop, zone);
Block* do_block = factory->NewBlock(nullptr, 2, false, nopos);
do_block->statements()->Add(do_block_, zone);
do_block->statements()->Add(get_value, zone);
Variable* dot_result = scope->NewTemporary(avfactory->dot_result_string());
yield_star = factory->NewDoExpression(do_block, dot_result, nopos);
Rewriter::Rewrite(parser_, yield_star, avfactory);
}
return yield_star;
}
Statement* ParserTraits::CheckCallable(Variable* var, Expression* error,
int pos) {
auto factory = parser_->factory();
auto avfactory = parser_->ast_value_factory();
const int nopos = RelocInfo::kNoPosition;
Statement* validate_var;
{
Expression* type_of = factory->NewUnaryOperation(
Token::TYPEOF, factory->NewVariableProxy(var), nopos);
Expression* function_literal =
factory->NewStringLiteral(avfactory->function_string(), nopos);
Expression* condition = factory->NewCompareOperation(
Token::EQ_STRICT, type_of, function_literal, nopos);
Statement* throw_call = factory->NewExpressionStatement(error, pos);
validate_var = factory->NewIfStatement(
condition, factory->NewEmptyStatement(nopos), throw_call, nopos);
}
return validate_var;
}
void ParserTraits::BuildIteratorClose(ZoneList<Statement*>* statements,
Variable* iterator,
Maybe<Variable*> input,
Variable* var_output) {
//
// This function adds four statements to [statements], corresponding to the
// following code:
//
// let iteratorReturn = iterator.return;
// if (IS_NULL_OR_UNDEFINED(iteratorReturn) {
// return {value: input, done: true};
// }
// output = %_Call(iteratorReturn, iterator, input);
// if (!IS_RECEIVER(output)) %ThrowIterResultNotAnObject(output);
//
// When the input variable is not given, the return statement becomes
// return {value: undefined, done: true};
// and %_Call has only two arguments:
// output = %_Call(iteratorReturn, iterator);
//
// The reason for allowing input is that BuildIteratorClose
// can then be reused to handle the return case in yield*.
//
const int nopos = RelocInfo::kNoPosition;
auto factory = parser_->factory();
auto avfactory = parser_->ast_value_factory();
auto zone = parser_->zone();
// let iteratorReturn = iterator.return;
Variable* var_return = var_output; // Reusing the output variable.
Statement* get_return;
{
Expression* iterator_proxy = factory->NewVariableProxy(iterator);
Expression* literal =
factory->NewStringLiteral(avfactory->return_string(), nopos);
Expression* property =
factory->NewProperty(iterator_proxy, literal, nopos);
Expression* return_proxy = factory->NewVariableProxy(var_return);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, return_proxy, property, nopos);
get_return = factory->NewExpressionStatement(assignment, nopos);
}
// if (IS_NULL_OR_UNDEFINED(iteratorReturn) {
// return {value: input, done: true};
// }
Statement* check_return;
{
Expression* condition = factory->NewCompareOperation(
Token::EQ, factory->NewVariableProxy(var_return),
factory->NewNullLiteral(nopos), nopos);
Expression* value = input.IsJust()
? static_cast<Expression*>(
factory->NewVariableProxy(input.FromJust()))
: factory->NewUndefinedLiteral(nopos);
Statement* return_input =
factory->NewReturnStatement(BuildIteratorResult(value, true), nopos);
check_return = factory->NewIfStatement(
condition, return_input, factory->NewEmptyStatement(nopos), nopos);
}
// output = %_Call(iteratorReturn, iterator, input);
Statement* call_return;
{
auto args = new (zone) ZoneList<Expression*>(3, zone);
args->Add(factory->NewVariableProxy(var_return), zone);
args->Add(factory->NewVariableProxy(iterator), zone);
if (input.IsJust()) {
args->Add(factory->NewVariableProxy(input.FromJust()), zone);
}
Expression* call =
factory->NewCallRuntime(Runtime::kInlineCall, args, nopos);
Expression* output_proxy = factory->NewVariableProxy(var_output);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, output_proxy, call, nopos);
call_return = factory->NewExpressionStatement(assignment, nopos);
}
// if (!IS_RECEIVER(output)) %ThrowIteratorResultNotAnObject(output);
Statement* validate_output;
{
Expression* is_receiver_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
is_receiver_call =
factory->NewCallRuntime(Runtime::kInlineIsJSReceiver, args, nopos);
}
Statement* throw_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
Expression* call = factory->NewCallRuntime(
Runtime::kThrowIteratorResultNotAnObject, args, nopos);
throw_call = factory->NewExpressionStatement(call, nopos);
}
validate_output = factory->NewIfStatement(
is_receiver_call, factory->NewEmptyStatement(nopos), throw_call, nopos);
}
statements->Add(get_return, zone);
statements->Add(check_return, zone);
statements->Add(call_return, zone);
statements->Add(validate_output, zone);
}
void ParserTraits::FinalizeIteratorUse(Variable* completion,
Expression* condition, Variable* iter,
Block* iterator_use, Block* target) {
if (!FLAG_harmony_iterator_close) return;
//
// This function adds two statements to [target], corresponding to the
// following code:
//
// completion = kNormalCompletion;
// try {
// try {
// iterator_use
// } catch(e) {
// if (completion === kAbruptCompletion) completion = kThrowCompletion;
// %ReThrow(e);
// }
// } finally {
// if (condition) {
// #BuildIteratorCloseForCompletion(iter, completion)
// }
// }
//
const int nopos = RelocInfo::kNoPosition;
auto factory = parser_->factory();
auto avfactory = parser_->ast_value_factory();
auto scope = parser_->scope_;
auto zone = parser_->zone();
// completion = kNormalCompletion;
Statement* initialize_completion;
{
Expression* proxy = factory->NewVariableProxy(completion);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, proxy,
factory->NewSmiLiteral(Parser::kNormalCompletion, nopos), nopos);
initialize_completion = factory->NewExpressionStatement(assignment, nopos);
}
// if (completion === kAbruptCompletion) completion = kThrowCompletion;
Statement* set_completion_throw;
{
Expression* condition = factory->NewCompareOperation(
Token::EQ_STRICT, factory->NewVariableProxy(completion),
factory->NewSmiLiteral(Parser::kAbruptCompletion, nopos), nopos);
Expression* proxy = factory->NewVariableProxy(completion);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, proxy,
factory->NewSmiLiteral(Parser::kThrowCompletion, nopos), nopos);
Statement* statement = factory->NewExpressionStatement(assignment, nopos);
set_completion_throw = factory->NewIfStatement(
condition, statement, factory->NewEmptyStatement(nopos), nopos);
}
// if (condition) {
// #BuildIteratorCloseForCompletion(iter, completion)
// }
Block* maybe_close;
{
Block* block = factory->NewBlock(nullptr, 2, true, nopos);
parser_->BuildIteratorCloseForCompletion(block->statements(), iter,
completion);
DCHECK(block->statements()->length() == 2);
maybe_close = factory->NewBlock(nullptr, 1, true, nopos);
maybe_close->statements()->Add(
factory->NewIfStatement(condition, block,
factory->NewEmptyStatement(nopos), nopos),
zone);
}
// try { #try_block }
// catch(e) {
// #set_completion_throw;
// %ReThrow(e);
// }
Statement* try_catch;
{
Scope* catch_scope = parser_->NewScope(scope, CATCH_SCOPE);
Variable* catch_variable =
catch_scope->DeclareLocal(avfactory->dot_catch_string(), VAR,
kCreatedInitialized, Variable::NORMAL);
catch_scope->set_is_hidden();
Statement* rethrow;
// We use %ReThrow rather than the ordinary throw because we want to
// preserve the original exception message. This is also why we create a
// TryCatchStatementForReThrow below (which does not clear the pending
// message), rather than a TryCatchStatement.
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(catch_variable), zone);
rethrow = factory->NewExpressionStatement(
factory->NewCallRuntime(Runtime::kReThrow, args, nopos), nopos);
}
Block* catch_block = factory->NewBlock(nullptr, 2, false, nopos);
catch_block->statements()->Add(set_completion_throw, zone);
catch_block->statements()->Add(rethrow, zone);
try_catch = factory->NewTryCatchStatementForReThrow(
iterator_use, catch_scope, catch_variable, catch_block, nopos);
}
// try { #try_catch } finally { #maybe_close }
Statement* try_finally;
{
Block* try_block = factory->NewBlock(nullptr, 1, false, nopos);
try_block->statements()->Add(try_catch, zone);
try_finally =
factory->NewTryFinallyStatement(try_block, maybe_close, nopos);
}
target->statements()->Add(initialize_completion, zone);
target->statements()->Add(try_finally, zone);
}
void ParserTraits::BuildIteratorCloseForCompletion(
ZoneList<Statement*>* statements, Variable* iterator,
Variable* completion) {
//
// This function adds two statements to [statements], corresponding to the
// following code:
//
// let iteratorReturn = iterator.return;
// if (!IS_NULL_OR_UNDEFINED(iteratorReturn)) {
// if (completion === kThrowCompletion) {
// if (!IS_CALLABLE(iteratorReturn)) {
// throw MakeTypeError(kReturnMethodNotCallable);
// }
// try { %_Call(iteratorReturn, iterator) } catch (_) { }
// } else {
// let output = %_Call(iteratorReturn, iterator);
// if (!IS_RECEIVER(output)) {
// %ThrowIterResultNotAnObject(output);
// }
// }
// }
//
const int nopos = RelocInfo::kNoPosition;
auto factory = parser_->factory();
auto avfactory = parser_->ast_value_factory();
auto scope = parser_->scope_;
auto zone = parser_->zone();
// let iteratorReturn = iterator.return;
Variable* var_return = scope->NewTemporary(avfactory->empty_string());
Statement* get_return;
{
Expression* iterator_proxy = factory->NewVariableProxy(iterator);
Expression* literal =
factory->NewStringLiteral(avfactory->return_string(), nopos);
Expression* property =
factory->NewProperty(iterator_proxy, literal, nopos);
Expression* return_proxy = factory->NewVariableProxy(var_return);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, return_proxy, property, nopos);
get_return = factory->NewExpressionStatement(assignment, nopos);
}
// if (!IS_CALLABLE(iteratorReturn)) {
// throw MakeTypeError(kReturnMethodNotCallable);
// }
Statement* check_return_callable;
{
Expression* throw_expr = NewThrowTypeError(
MessageTemplate::kReturnMethodNotCallable,
avfactory->empty_string(), nopos);
check_return_callable = CheckCallable(var_return, throw_expr, nopos);
}
// try { %_Call(iteratorReturn, iterator) } catch (_) { }
Statement* try_call_return;
{
auto args = new (zone) ZoneList<Expression*>(2, zone);
args->Add(factory->NewVariableProxy(var_return), zone);
args->Add(factory->NewVariableProxy(iterator), zone);
Expression* call =
factory->NewCallRuntime(Runtime::kInlineCall, args, nopos);
Block* try_block = factory->NewBlock(nullptr, 1, false, nopos);
try_block->statements()->Add(factory->NewExpressionStatement(call, nopos),
zone);
Block* catch_block = factory->NewBlock(nullptr, 0, false, nopos);
Scope* catch_scope = NewScope(scope, CATCH_SCOPE);
Variable* catch_variable = catch_scope->DeclareLocal(
avfactory->dot_catch_string(), VAR, kCreatedInitialized,
Variable::NORMAL);
catch_scope->set_is_hidden();
try_call_return = factory->NewTryCatchStatement(
try_block, catch_scope, catch_variable, catch_block, nopos);
}
// let output = %_Call(iteratorReturn, iterator);
// if (!IS_RECEIVER(output)) {
// %ThrowIteratorResultNotAnObject(output);
// }
Block* validate_return;
{
Variable* var_output = scope->NewTemporary(avfactory->empty_string());
Statement* call_return;
{
auto args = new (zone) ZoneList<Expression*>(2, zone);
args->Add(factory->NewVariableProxy(var_return), zone);
args->Add(factory->NewVariableProxy(iterator), zone);
Expression* call =
factory->NewCallRuntime(Runtime::kInlineCall, args, nopos);
Expression* output_proxy = factory->NewVariableProxy(var_output);
Expression* assignment =
factory->NewAssignment(Token::ASSIGN, output_proxy, call, nopos);
call_return = factory->NewExpressionStatement(assignment, nopos);
}
Expression* is_receiver_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
is_receiver_call =
factory->NewCallRuntime(Runtime::kInlineIsJSReceiver, args, nopos);
}
Statement* throw_call;
{
auto args = new (zone) ZoneList<Expression*>(1, zone);
args->Add(factory->NewVariableProxy(var_output), zone);
Expression* call = factory->NewCallRuntime(
Runtime::kThrowIteratorResultNotAnObject, args, nopos);
throw_call = factory->NewExpressionStatement(call, nopos);
}
Statement* check_return = factory->NewIfStatement(
is_receiver_call, factory->NewEmptyStatement(nopos), throw_call, nopos);
validate_return = factory->NewBlock(nullptr, 2, false, nopos);
validate_return->statements()->Add(call_return, zone);
validate_return->statements()->Add(check_return, zone);
}
// if (completion === kThrowCompletion) {
// #check_return_callable;
// #try_call_return;
// } else {
// #validate_return;
// }
Statement* call_return_carefully;
{
Expression* condition = factory->NewCompareOperation(
Token::EQ_STRICT, factory->NewVariableProxy(completion),
factory->NewSmiLiteral(Parser::kThrowCompletion, nopos), nopos);
Block* then_block = factory->NewBlock(nullptr, 2, false, nopos);
then_block->statements()->Add(check_return_callable, zone);
then_block->statements()->Add(try_call_return, zone);
call_return_carefully =
factory->NewIfStatement(condition, then_block, validate_return, nopos);
}
// if (!IS_NULL_OR_UNDEFINED(iteratorReturn)) { ... }
Statement* maybe_call_return;
{
Expression* condition = factory->NewCompareOperation(
Token::EQ, factory->NewVariableProxy(var_return),
factory->NewNullLiteral(nopos), nopos);
maybe_call_return =
factory->NewIfStatement(condition, factory->NewEmptyStatement(nopos),
call_return_carefully, nopos);
}
statements->Add(get_return, zone);
statements->Add(maybe_call_return, zone);
}
Statement* ParserTraits::FinalizeForOfStatement(ForOfStatement* loop, int pos) {
if (!FLAG_harmony_iterator_close) return loop;
//
// This function replaces the loop with the following wrapping:
//
// let each;
// let completion = kNormalCompletion;
// try {
// try {
// #loop;
// } catch(e) {
// if (completion === kAbruptCompletion) completion = kThrowCompletion;
// %ReThrow(e);
// }
// } finally {
// if (!(completion === kNormalCompletion || IS_UNDEFINED(#iterator))) {
// #BuildIteratorCloseForCompletion(#iterator, completion)
// }
// }
//
// where the loop's body is wrapped as follows:
//
// {
// #loop-body
// {{completion = kNormalCompletion;}}
// }
//
// and the loop's assign_each is wrapped as follows
//
// do {
// {{completion = kAbruptCompletion;}}
// #assign-each
// }
//
const int nopos = RelocInfo::kNoPosition;
auto factory = parser_->factory();
auto avfactory = parser_->ast_value_factory();
auto scope = parser_->scope_;
auto zone = parser_->zone();
Variable* var_completion = scope->NewTemporary(avfactory->empty_string());
// let each;
Variable* var_each = scope->NewTemporary(avfactory->empty_string());
Statement* initialize_each;
{
Expression* proxy = factory->NewVariableProxy(var_each);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, proxy,
factory->NewUndefinedLiteral(nopos), nopos);
initialize_each =
factory->NewExpressionStatement(assignment, nopos);
}
// !(completion === kNormalCompletion || IS_UNDEFINED(#iterator))
Expression* closing_condition;
{
Expression* lhs = factory->NewCompareOperation(
Token::EQ_STRICT, factory->NewVariableProxy(var_completion),
factory->NewSmiLiteral(Parser::kNormalCompletion, nopos), nopos);
Expression* rhs = factory->NewCompareOperation(
Token::EQ_STRICT, factory->NewVariableProxy(loop->iterator()),
factory->NewUndefinedLiteral(nopos), nopos);
closing_condition = factory->NewUnaryOperation(
Token::NOT, factory->NewBinaryOperation(Token::OR, lhs, rhs, nopos),
nopos);
}
// {{completion = kNormalCompletion;}}
Statement* set_completion_normal;
{
Expression* proxy = factory->NewVariableProxy(var_completion);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, proxy,
factory->NewSmiLiteral(Parser::kNormalCompletion, nopos), nopos);
Block* block = factory->NewBlock(nullptr, 1, true, nopos);
block->statements()->Add(
factory->NewExpressionStatement(assignment, nopos), zone);
set_completion_normal = block;
}
// {{completion = kAbruptCompletion;}}
Statement* set_completion_abrupt;
{
Expression* proxy = factory->NewVariableProxy(var_completion);
Expression* assignment = factory->NewAssignment(
Token::ASSIGN, proxy,
factory->NewSmiLiteral(Parser::kAbruptCompletion, nopos), nopos);
Block* block = factory->NewBlock(nullptr, 1, true, nopos);
block->statements()->Add(factory->NewExpressionStatement(assignment, nopos),
zone);
set_completion_abrupt = block;
}
// { #loop-body; #set_completion_normal }
Block* new_body = factory->NewBlock(nullptr, 2, false, nopos);
{
new_body->statements()->Add(loop->body(), zone);
new_body->statements()->Add(set_completion_normal, zone);
}
// { #set_completion_abrupt; #assign-each }
Block* new_assign_each = factory->NewBlock(nullptr, 2, false, nopos);
{
new_assign_each->statements()->Add(set_completion_abrupt, zone);
new_assign_each->statements()->Add(
factory->NewExpressionStatement(loop->assign_each(), nopos), zone);
}
// Now put things together.
loop->set_body(new_body);
loop->set_assign_each(
factory->NewDoExpression(new_assign_each, var_each, nopos));
Statement* final_loop;
{
Block* target = factory->NewBlock(nullptr, 3, false, nopos);
target->statements()->Add(initialize_each, zone);
Block* try_block = factory->NewBlock(nullptr, 1, false, nopos);
try_block->statements()->Add(loop, zone);
FinalizeIteratorUse(var_completion, closing_condition, loop->iterator(),
try_block, target);
final_loop = target;
}
return final_loop;
}
} // namespace internal
} // namespace v8