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android / platform / external / chromium_org / v8 / 8bf7b0b7f00a210fa038990eade174de75702a1f / . / src / parser.cc
blob: c5bf0d977708df914299099f36f197a0e5b55eca [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/v8.h"
#include "src/api.h"
#include "src/ast.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/parser.h"
#include "src/preparser.h"
#include "src/runtime/runtime.h"
#include "src/scanner-character-streams.h"
#include "src/scopeinfo.h"
#include "src/string-stream.h"
namespace v8 {
namespace internal {
RegExpBuilder::RegExpBuilder(Zone* zone)
: zone_(zone),
pending_empty_(false),
characters_(NULL),
terms_(),
alternatives_()
#ifdef DEBUG
, last_added_(ADD_NONE)
#endif
{}
void RegExpBuilder::FlushCharacters() {
pending_empty_ = false;
if (characters_ != NULL) {
RegExpTree* atom = new(zone()) RegExpAtom(characters_->ToConstVector());
characters_ = NULL;
text_.Add(atom, zone());
LAST(ADD_ATOM);
}
}
void RegExpBuilder::FlushText() {
FlushCharacters();
int num_text = text_.length();
if (num_text == 0) {
return;
} else if (num_text == 1) {
terms_.Add(text_.last(), zone());
} else {
RegExpText* text = new(zone()) RegExpText(zone());
for (int i = 0; i < num_text; i++)
text_.Get(i)->AppendToText(text, zone());
terms_.Add(text, zone());
}
text_.Clear();
}
void RegExpBuilder::AddCharacter(uc16 c) {
pending_empty_ = false;
if (characters_ == NULL) {
characters_ = new(zone()) ZoneList<uc16>(4, zone());
}
characters_->Add(c, zone());
LAST(ADD_CHAR);
}
void RegExpBuilder::AddEmpty() {
pending_empty_ = true;
}
void RegExpBuilder::AddAtom(RegExpTree* term) {
if (term->IsEmpty()) {
AddEmpty();
return;
}
if (term->IsTextElement()) {
FlushCharacters();
text_.Add(term, zone());
} else {
FlushText();
terms_.Add(term, zone());
}
LAST(ADD_ATOM);
}
void RegExpBuilder::AddAssertion(RegExpTree* assert) {
FlushText();
terms_.Add(assert, zone());
LAST(ADD_ASSERT);
}
void RegExpBuilder::NewAlternative() {
FlushTerms();
}
void RegExpBuilder::FlushTerms() {
FlushText();
int num_terms = terms_.length();
RegExpTree* alternative;
if (num_terms == 0) {
alternative = RegExpEmpty::GetInstance();
} else if (num_terms == 1) {
alternative = terms_.last();
} else {
alternative = new(zone()) RegExpAlternative(terms_.GetList(zone()));
}
alternatives_.Add(alternative, zone());
terms_.Clear();
LAST(ADD_NONE);
}
RegExpTree* RegExpBuilder::ToRegExp() {
FlushTerms();
int num_alternatives = alternatives_.length();
if (num_alternatives == 0) {
return RegExpEmpty::GetInstance();
}
if (num_alternatives == 1) {
return alternatives_.last();
}
return new(zone()) RegExpDisjunction(alternatives_.GetList(zone()));
}
void RegExpBuilder::AddQuantifierToAtom(
int min, int max, RegExpQuantifier::QuantifierType quantifier_type) {
if (pending_empty_) {
pending_empty_ = false;
return;
}
RegExpTree* atom;
if (characters_ != NULL) {
DCHECK(last_added_ == ADD_CHAR);
// Last atom was character.
Vector<const uc16> char_vector = characters_->ToConstVector();
int num_chars = char_vector.length();
if (num_chars > 1) {
Vector<const uc16> prefix = char_vector.SubVector(0, num_chars - 1);
text_.Add(new(zone()) RegExpAtom(prefix), zone());
char_vector = char_vector.SubVector(num_chars - 1, num_chars);
}
characters_ = NULL;
atom = new(zone()) RegExpAtom(char_vector);
FlushText();
} else if (text_.length() > 0) {
DCHECK(last_added_ == ADD_ATOM);
atom = text_.RemoveLast();
FlushText();
} else if (terms_.length() > 0) {
DCHECK(last_added_ == ADD_ATOM);
atom = terms_.RemoveLast();
if (atom->max_match() == 0) {
// Guaranteed to only match an empty string.
LAST(ADD_TERM);
if (min == 0) {
return;
}
terms_.Add(atom, zone());
return;
}
} else {
// Only call immediately after adding an atom or character!
UNREACHABLE();
return;
}
terms_.Add(
new(zone()) RegExpQuantifier(min, max, quantifier_type, atom), zone());
LAST(ADD_TERM);
}
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() {
// 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() {
if (compile_options() == ScriptCompiler::kNoCompileOptions) {
cached_parse_data_ = NULL;
} else {
DCHECK(info_->cached_data() != NULL);
if (compile_options() == ScriptCompiler::kConsumeParserCache) {
cached_parse_data_ = new ParseData(*info_->cached_data());
}
}
}
Scope* Parser::NewScope(Scope* parent, ScopeType scope_type) {
DCHECK(ast_value_factory());
Scope* result =
new (zone()) Scope(parent, scope_type, ast_value_factory(), zone());
result->Initialize();
return result;
}
// ----------------------------------------------------------------------------
// 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, AstNode* node)
: variable_(variable), node_(node), previous_(*variable) {
*variable = this;
}
~Target() {
*variable_ = previous_;
}
Target* previous() { return previous_; }
AstNode* node() { return node_; }
private:
Target** variable_;
AstNode* node_;
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::IsEvalOrArguments(const AstRawString* identifier) const {
return identifier == parser_->ast_value_factory()->eval_string() ||
identifier == parser_->ast_value_factory()->arguments_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()->AsVariableProxy() != NULL &&
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->AsProperty() != NULL &&
right->AsFunctionLiteral() != NULL) {
right->AsFunctionLiteral()->set_pretenure();
}
}
void ParserTraits::CheckPossibleEvalCall(Expression* expression,
Scope* scope) {
VariableProxy* callee = expression->AsVariableProxy();
if (callee != NULL &&
callee->raw_name() == parser_->ast_value_factory()->eval_string()) {
scope->DeclarationScope()->RecordEvalCall();
}
}
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<AstConstructionVisitor>* 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();
switch (op) {
case Token::ADD:
*x = factory->NewNumberLiteral(x_val + y_val, pos);
return true;
case Token::SUB:
*x = factory->NewNumberLiteral(x_val - y_val, pos);
return true;
case Token::MUL:
*x = factory->NewNumberLiteral(x_val * y_val, pos);
return true;
case Token::DIV:
*x = factory->NewNumberLiteral(x_val / y_val, pos);
return true;
case Token::BIT_OR: {
int value = DoubleToInt32(x_val) | DoubleToInt32(y_val);
*x = factory->NewNumberLiteral(value, pos);
return true;
}
case Token::BIT_AND: {
int value = DoubleToInt32(x_val) & DoubleToInt32(y_val);
*x = factory->NewNumberLiteral(value, pos);
return true;
}
case Token::BIT_XOR: {
int value = DoubleToInt32(x_val) ^ DoubleToInt32(y_val);
*x = factory->NewNumberLiteral(value, pos);
return true;
}
case Token::SHL: {
int value = DoubleToInt32(x_val) << (DoubleToInt32(y_val) & 0x1f);
*x = factory->NewNumberLiteral(value, pos);
return true;
}
case Token::SHR: {
uint32_t shift = DoubleToInt32(y_val) & 0x1f;
uint32_t value = DoubleToUint32(x_val) >> shift;
*x = factory->NewNumberLiteral(value, pos);
return true;
}
case Token::SAR: {
uint32_t shift = DoubleToInt32(y_val) & 0x1f;
int value = ArithmeticShiftRight(DoubleToInt32(x_val), shift);
*x = factory->NewNumberLiteral(value, pos);
return true;
}
default:
break;
}
}
return false;
}
Expression* ParserTraits::BuildUnaryExpression(
Expression* expression, Token::Value op, int pos,
AstNodeFactory<AstConstructionVisitor>* 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();
switch (op) {
case Token::ADD:
return expression;
case Token::SUB:
return factory->NewNumberLiteral(-value, pos);
case Token::BIT_NOT:
return factory->NewNumberLiteral(~DoubleToInt32(value), pos);
default:
break;
}
}
}
// Desugar '+foo' => 'foo*1'
if (op == Token::ADD) {
return factory->NewBinaryOperation(
Token::MUL, expression, factory->NewNumberLiteral(1, pos), 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::NewThrowReferenceError(const char* message, int pos) {
return NewThrowError(
parser_->ast_value_factory()->make_reference_error_string(), message,
parser_->ast_value_factory()->empty_string(), pos);
}
Expression* ParserTraits::NewThrowSyntaxError(
const char* message, const AstRawString* arg, int pos) {
return NewThrowError(parser_->ast_value_factory()->make_syntax_error_string(),
message, arg, pos);
}
Expression* ParserTraits::NewThrowTypeError(
const char* message, const AstRawString* arg, int pos) {
return NewThrowError(parser_->ast_value_factory()->make_type_error_string(),
message, arg, pos);
}
Expression* ParserTraits::NewThrowError(
const AstRawString* constructor, const char* message,
const AstRawString* arg, int pos) {
Zone* zone = parser_->zone();
const AstRawString* type =
parser_->ast_value_factory()->GetOneByteString(message);
ZoneList<Expression*>* args = new (zone) ZoneList<Expression*>(2, zone);
args->Add(parser_->factory()->NewStringLiteral(type, pos), zone);
args->Add(parser_->factory()->NewStringLiteral(arg, pos), zone);
CallRuntime* call_constructor =
parser_->factory()->NewCallRuntime(constructor, NULL, args, pos);
return parser_->factory()->NewThrow(call_constructor, pos);
}
void ParserTraits::ReportMessageAt(Scanner::Location source_location,
const char* message,
const char* arg,
bool is_reference_error) {
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_->has_pending_error_ = true;
parser_->pending_error_location_ = source_location;
parser_->pending_error_message_ = message;
parser_->pending_error_char_arg_ = arg;
parser_->pending_error_arg_ = NULL;
parser_->pending_error_is_reference_error_ = is_reference_error;
}
void ParserTraits::ReportMessage(const char* message,
const char* arg,
bool is_reference_error) {
Scanner::Location source_location = parser_->scanner()->location();
ReportMessageAt(source_location, message, arg, is_reference_error);
}
void ParserTraits::ReportMessage(const char* message,
const AstRawString* arg,
bool is_reference_error) {
Scanner::Location source_location = parser_->scanner()->location();
ReportMessageAt(source_location, message, arg, is_reference_error);
}
void ParserTraits::ReportMessageAt(Scanner::Location source_location,
const char* message,
const AstRawString* arg,
bool is_reference_error) {
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_->has_pending_error_ = true;
parser_->pending_error_location_ = source_location;
parser_->pending_error_message_ = message;
parser_->pending_error_char_arg_ = NULL;
parser_->pending_error_arg_ = arg;
parser_->pending_error_is_reference_error_ = is_reference_error;
}
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, Vector<char>(array, arraysize(array)));
return 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<AstConstructionVisitor>* factory, int pos) {
return factory->NewVariableProxy(scope->receiver(), pos);
}
Expression* ParserTraits::SuperReference(
Scope* scope, AstNodeFactory<AstConstructionVisitor>* factory, int pos) {
return factory->NewSuperReference(
ThisExpression(scope, factory, pos)->AsVariableProxy(),
pos);
}
Expression* ParserTraits::ClassExpression(
const AstRawString* name, Expression* extends, Expression* constructor,
ZoneList<ObjectLiteral::Property*>* properties, int start_position,
int end_position, AstNodeFactory<AstConstructionVisitor>* factory) {
return factory->NewClassLiteral(name, extends, constructor, properties,
start_position, end_position);
}
Literal* ParserTraits::ExpressionFromLiteral(
Token::Value token, int pos,
Scanner* scanner,
AstNodeFactory<AstConstructionVisitor>* 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::NUMBER: {
double value = scanner->DoubleValue();
return factory->NewNumberLiteral(value, pos);
}
default:
DCHECK(false);
}
return NULL;
}
Expression* ParserTraits::ExpressionFromIdentifier(
const AstRawString* name, int pos, Scope* scope,
AstNodeFactory<AstConstructionVisitor>* factory) {
if (parser_->fni_ != NULL) parser_->fni_->PushVariableName(name);
// The name may refer to a module instance object, so its type is unknown.
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Variable %.*s ", name->length(), name->raw_data());
#endif
Interface* interface = Interface::NewUnknown(parser_->zone());
return scope->NewUnresolved(factory, name, interface, pos);
}
Expression* ParserTraits::ExpressionFromString(
int pos, Scanner* scanner,
AstNodeFactory<AstConstructionVisitor>* 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<AstConstructionVisitor>* factory) {
Expression* iterator_symbol_literal =
factory->NewSymbolLiteral("symbolIterator", RelocInfo::kNoPosition);
int pos = iterable->position();
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<AstConstructionVisitor>* 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,
bool name_is_strict_reserved, FunctionKind kind,
int function_token_position, FunctionLiteral::FunctionType type,
FunctionLiteral::ArityRestriction arity_restriction, bool* ok) {
return parser_->ParseFunctionLiteral(
name, function_name_location, name_is_strict_reserved, kind,
function_token_position, type, arity_restriction, ok);
}
Parser::Parser(CompilationInfo* info, ParseInfo* parse_info)
: ParserBase<ParserTraits>(&scanner_, parse_info->stack_limit,
info->extension(), NULL, info->zone(), this),
scanner_(parse_info->unicode_cache),
reusable_preparser_(NULL),
original_scope_(NULL),
target_stack_(NULL),
cached_parse_data_(NULL),
info_(info),
has_pending_error_(false),
pending_error_message_(NULL),
pending_error_arg_(NULL),
pending_error_char_arg_(NULL),
total_preparse_skipped_(0),
pre_parse_timer_(NULL) {
DCHECK(!script().is_null() || info->source_stream() != NULL);
set_allow_harmony_scoping(!info->is_native() && FLAG_harmony_scoping);
set_allow_modules(!info->is_native() && FLAG_harmony_modules);
set_allow_natives_syntax(FLAG_allow_natives_syntax || info->is_native());
set_allow_lazy(false); // Must be explicitly enabled.
set_allow_arrow_functions(FLAG_harmony_arrow_functions);
set_allow_harmony_numeric_literals(FLAG_harmony_numeric_literals);
set_allow_classes(FLAG_harmony_classes);
set_allow_harmony_object_literals(FLAG_harmony_object_literals);
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->SetAstValueFactory(
new AstValueFactory(zone(), parse_info->hash_seed));
}
}
FunctionLiteral* Parser::ParseProgram() {
// TODO(bmeurer): We temporarily need to pass allow_nesting = true here,
// see comment for HistogramTimerScope class.
// It's OK to use the counters here, since this function is only called in
// the main thread.
HistogramTimerScope timer_scope(isolate()->counters()->parse(), true);
Handle<String> source(String::cast(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;
debug_saved_compile_options_ = compile_options();
if (compile_options() == ScriptCompiler::kProduceParserCache) {
log_ = &recorder;
} else if (compile_options() == ScriptCompiler::kConsumeParserCache) {
cached_parse_data_->Initialize();
}
source = String::Flatten(source);
FunctionLiteral* result;
Scope* top_scope = NULL;
Scope* eval_scope = NULL;
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(), &top_scope, &eval_scope);
} else {
GenericStringUtf16CharacterStream stream(source, 0, source->length());
scanner_.Initialize(&stream);
result = DoParseProgram(info(), &top_scope, &eval_scope);
}
top_scope->set_end_position(source->length());
if (eval_scope != NULL) {
eval_scope->set_end_position(source->length());
}
HandleSourceURLComments();
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());
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 (compile_options() == ScriptCompiler::kProduceParserCache) {
if (result != NULL) *info_->cached_data() = recorder.GetScriptData();
log_ = NULL;
}
return result;
}
FunctionLiteral* Parser::DoParseProgram(CompilationInfo* info, Scope** scope,
Scope** eval_scope) {
DCHECK(scope_ == NULL);
DCHECK(target_stack_ == NULL);
FunctionLiteral* result = NULL;
{
*scope = NewScope(scope_, GLOBAL_SCOPE);
info->SetGlobalScope(*scope);
if (!info->context().is_null() && !info->context()->IsNativeContext()) {
*scope = Scope::DeserializeScopeChain(*info->context(), *scope, zone());
// 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.
ast_value_factory()->Internalize(isolate());
}
original_scope_ = *scope;
if (info->is_eval()) {
if (!(*scope)->is_global_scope() || info->strict_mode() == STRICT) {
*scope = NewScope(*scope, EVAL_SCOPE);
}
} else if (info->is_global()) {
*scope = NewScope(*scope, GLOBAL_SCOPE);
}
(*scope)->set_start_position(0);
// End position will be set by the caller.
// Compute the parsing mode.
Mode mode = (FLAG_lazy && allow_lazy()) ? PARSE_LAZILY : PARSE_EAGERLY;
if (allow_natives_syntax() || extension_ != NULL ||
(*scope)->is_eval_scope()) {
mode = PARSE_EAGERLY;
}
ParsingModeScope parsing_mode(this, mode);
// Enters 'scope'.
AstNodeFactory<AstConstructionVisitor> function_factory(
ast_value_factory());
FunctionState function_state(&function_state_, &scope_, *scope,
&function_factory);
scope_->SetStrictMode(info->strict_mode());
ZoneList<Statement*>* body = new(zone()) ZoneList<Statement*>(16, zone());
bool ok = true;
int beg_pos = scanner()->location().beg_pos;
ParseSourceElements(body, Token::EOS, info->is_eval(), true, eval_scope,
&ok);
if (ok && strict_mode() == STRICT) {
CheckOctalLiteral(beg_pos, scanner()->location().end_pos, &ok);
}
if (ok && allow_harmony_scoping() && strict_mode() == STRICT) {
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("single_function_literal");
ok = false;
}
}
if (ok) {
result = factory()->NewFunctionLiteral(
ast_value_factory()->empty_string(), ast_value_factory(), scope_,
body, function_state.materialized_literal_count(),
function_state.expected_property_count(),
function_state.handler_count(), 0,
FunctionLiteral::kNoDuplicateParameters,
FunctionLiteral::ANONYMOUS_EXPRESSION, FunctionLiteral::kGlobalOrEval,
FunctionLiteral::kNotParenthesized, FunctionKind::kNormalFunction, 0);
result->set_ast_properties(factory()->visitor()->ast_properties());
result->set_dont_optimize_reason(
factory()->visitor()->dont_optimize_reason());
}
}
// Make sure the target stack is empty.
DCHECK(target_stack_ == NULL);
return result;
}
FunctionLiteral* Parser::ParseLazy() {
// It's OK to use the counters here, since this function is only called in
// the main thread.
HistogramTimerScope timer_scope(isolate()->counters()->parse_lazy());
Handle<String> source(String::cast(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(&stream);
} else {
GenericStringUtf16CharacterStream stream(source,
shared_info->start_position(),
shared_info->end_position());
result = ParseLazy(&stream);
}
if (FLAG_trace_parse && result != NULL) {
double ms = timer.Elapsed().InMillisecondsF();
SmartArrayPointer<char> name_chars = result->debug_name()->ToCString();
PrintF("[parsing function: %s - took %0.3f ms]\n", name_chars.get(), ms);
}
return result;
}
FunctionLiteral* Parser::ParseLazy(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_, GLOBAL_SCOPE);
info()->SetGlobalScope(scope);
if (!info()->closure().is_null()) {
scope = Scope::DeserializeScopeChain(info()->closure()->context(), scope,
zone());
}
original_scope_ = scope;
AstNodeFactory<AstConstructionVisitor> function_factory(
ast_value_factory());
FunctionState function_state(&function_state_, &scope_, scope,
&function_factory);
DCHECK(scope->strict_mode() == SLOPPY || info()->strict_mode() == STRICT);
DCHECK(info()->strict_mode() == shared_info->strict_mode());
scope->SetStrictMode(shared_info->strict_mode());
FunctionLiteral::FunctionType function_type = shared_info->is_expression()
? (shared_info->is_anonymous()
? FunctionLiteral::ANONYMOUS_EXPRESSION
: FunctionLiteral::NAMED_EXPRESSION)
: FunctionLiteral::DECLARATION;
bool ok = true;
if (shared_info->is_arrow()) {
Expression* expression = ParseExpression(false, &ok);
DCHECK(expression->IsFunctionLiteral());
result = expression->AsFunctionLiteral();
} else {
result = ParseFunctionLiteral(raw_name, Scanner::Location::invalid(),
false, // Strict mode name already checked.
shared_info->kind(), RelocInfo::kNoPosition,
function_type,
FunctionLiteral::NORMAL_ARITY, &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::ParseSourceElements(ZoneList<Statement*>* processor,
int end_token, bool is_eval, bool is_global,
Scope** eval_scope, bool* ok) {
// SourceElements ::
// (ModuleElement)* <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(processor != 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;
if (is_global && !is_eval) {
stat = ParseModuleElement(NULL, CHECK_OK);
} else {
stat = ParseBlockElement(NULL, 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) and "use asm" directive. Only
// one can be present.
if (strict_mode() == SLOPPY &&
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) {
// TODO(mstarzinger): Global strict eval calls, need their own scope
// as specified in ES5 10.4.2(3). The correct fix would be to always
// add this scope in DoParseProgram(), but that requires adaptations
// all over the code base, so we go with a quick-fix for now.
// In the same manner, we have to patch the parsing mode.
if (is_eval && !scope_->is_eval_scope()) {
DCHECK(scope_->is_global_scope());
Scope* scope = NewScope(scope_, EVAL_SCOPE);
scope->set_start_position(scope_->start_position());
scope->set_end_position(scope_->end_position());
scope_ = scope;
if (eval_scope != NULL) {
// Caller will correct the positions of the ad hoc eval scope.
*eval_scope = scope;
}
mode_ = PARSE_EAGERLY;
}
scope_->SetStrictMode(STRICT);
// "use strict" is the only directive for now.
directive_prologue = false;
} 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 {
// End of the directive prologue.
directive_prologue = false;
}
}
processor->Add(stat, zone());
}
return 0;
}
Statement* Parser::ParseModuleElement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// (Ecma 262 5th Edition, clause 14):
// SourceElement:
// Statement
// FunctionDeclaration
//
// In harmony mode we allow additionally the following productions
// ModuleElement:
// LetDeclaration
// ConstDeclaration
// ModuleDeclaration
// ImportDeclaration
// ExportDeclaration
// GeneratorDeclaration
switch (peek()) {
case Token::FUNCTION:
return ParseFunctionDeclaration(NULL, ok);
case Token::CLASS:
return ParseClassDeclaration(NULL, ok);
case Token::IMPORT:
return ParseImportDeclaration(ok);
case Token::EXPORT:
return ParseExportDeclaration(ok);
case Token::CONST:
return ParseVariableStatement(kModuleElement, NULL, ok);
case Token::LET:
DCHECK(allow_harmony_scoping());
if (strict_mode() == STRICT) {
return ParseVariableStatement(kModuleElement, NULL, ok);
}
// Fall through.
default: {
Statement* stmt = ParseStatement(labels, CHECK_OK);
// Handle 'module' as a context-sensitive keyword.
if (FLAG_harmony_modules &&
peek() == Token::IDENTIFIER &&
!scanner()->HasAnyLineTerminatorBeforeNext() &&
stmt != NULL) {
ExpressionStatement* estmt = stmt->AsExpressionStatement();
if (estmt != NULL && estmt->expression()->AsVariableProxy() != NULL &&
estmt->expression()->AsVariableProxy()->raw_name() ==
ast_value_factory()->module_string() &&
!scanner()->literal_contains_escapes()) {
return ParseModuleDeclaration(NULL, ok);
}
}
return stmt;
}
}
}
Statement* Parser::ParseModuleDeclaration(ZoneList<const AstRawString*>* names,
bool* ok) {
// ModuleDeclaration:
// 'module' Identifier Module
int pos = peek_position();
const AstRawString* name =
ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Module %.*s ", name->length(), name->raw_data());
#endif
Module* module = ParseModule(CHECK_OK);
VariableProxy* proxy = NewUnresolved(name, MODULE, module->interface());
Declaration* declaration =
factory()->NewModuleDeclaration(proxy, module, scope_, pos);
Declare(declaration, true, CHECK_OK);
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Module %.*s ", name->length(), name->raw_data());
if (FLAG_print_interfaces) {
PrintF("module %.*s: ", name->length(), name->raw_data());
module->interface()->Print();
}
#endif
if (names) names->Add(name, zone());
if (module->body() == NULL)
return factory()->NewEmptyStatement(pos);
else
return factory()->NewModuleStatement(proxy, module->body(), pos);
}
Module* Parser::ParseModule(bool* ok) {
// Module:
// '{' ModuleElement '}'
// '=' ModulePath ';'
// 'at' String ';'
switch (peek()) {
case Token::LBRACE:
return ParseModuleLiteral(ok);
case Token::ASSIGN: {
Expect(Token::ASSIGN, CHECK_OK);
Module* result = ParseModulePath(CHECK_OK);
ExpectSemicolon(CHECK_OK);
return result;
}
default: {
ExpectContextualKeyword(CStrVector("at"), CHECK_OK);
Module* result = ParseModuleUrl(CHECK_OK);
ExpectSemicolon(CHECK_OK);
return result;
}
}
}
Module* Parser::ParseModuleLiteral(bool* ok) {
// Module:
// '{' ModuleElement '}'
int pos = peek_position();
// Construct block expecting 16 statements.
Block* body = factory()->NewBlock(NULL, 16, false, RelocInfo::kNoPosition);
#ifdef DEBUG
if (FLAG_print_interface_details) PrintF("# Literal ");
#endif
Scope* scope = NewScope(scope_, MODULE_SCOPE);
Expect(Token::LBRACE, CHECK_OK);
scope->set_start_position(scanner()->location().beg_pos);
scope->SetStrictMode(STRICT);
{
BlockState block_state(&scope_, scope);
TargetCollector collector(zone());
Target target(&this->target_stack_, &collector);
Target target_body(&this->target_stack_, body);
while (peek() != Token::RBRACE) {
Statement* stat = ParseModuleElement(NULL, CHECK_OK);
if (stat && !stat->IsEmpty()) {
body->AddStatement(stat, zone());
}
}
}
Expect(Token::RBRACE, CHECK_OK);
scope->set_end_position(scanner()->location().end_pos);
body->set_scope(scope);
// Check that all exports are bound.
Interface* interface = scope->interface();
for (Interface::Iterator it = interface->iterator();
!it.done(); it.Advance()) {
if (scope->LookupLocal(it.name()) == NULL) {
ParserTraits::ReportMessage("module_export_undefined", it.name());
*ok = false;
return NULL;
}
}
interface->MakeModule(ok);
DCHECK(*ok);
interface->Freeze(ok);
DCHECK(*ok);
return factory()->NewModuleLiteral(body, interface, pos);
}
Module* Parser::ParseModulePath(bool* ok) {
// ModulePath:
// Identifier
// ModulePath '.' Identifier
int pos = peek_position();
Module* result = ParseModuleVariable(CHECK_OK);
while (Check(Token::PERIOD)) {
const AstRawString* name = ParseIdentifierName(CHECK_OK);
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Path .%.*s ", name->length(), name->raw_data());
#endif
Module* member = factory()->NewModulePath(result, name, pos);
result->interface()->Add(name, member->interface(), zone(), ok);
if (!*ok) {
#ifdef DEBUG
if (FLAG_print_interfaces) {
PrintF("PATH TYPE ERROR at '%.*s'\n", name->length(), name->raw_data());
PrintF("result: ");
result->interface()->Print();
PrintF("member: ");
member->interface()->Print();
}
#endif
ParserTraits::ReportMessage("invalid_module_path", name);
return NULL;
}
result = member;
}
return result;
}
Module* Parser::ParseModuleVariable(bool* ok) {
// ModulePath:
// Identifier
int pos = peek_position();
const AstRawString* name =
ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Module variable %.*s ", name->length(), name->raw_data());
#endif
VariableProxy* proxy = scope_->NewUnresolved(
factory(), name, Interface::NewModule(zone()),
scanner()->location().beg_pos);
return factory()->NewModuleVariable(proxy, pos);
}
Module* Parser::ParseModuleUrl(bool* ok) {
// Module:
// String
int pos = peek_position();
Expect(Token::STRING, CHECK_OK);
const AstRawString* symbol = GetSymbol(scanner());
// TODO(ES6): Request JS resource from environment...
#ifdef DEBUG
if (FLAG_print_interface_details) PrintF("# Url ");
#endif
// Create an empty literal as long as the feature isn't finished.
USE(symbol);
Scope* scope = NewScope(scope_, MODULE_SCOPE);
Block* body = factory()->NewBlock(NULL, 1, false, RelocInfo::kNoPosition);
body->set_scope(scope);
Interface* interface = scope->interface();
Module* result = factory()->NewModuleLiteral(body, interface, pos);
interface->Freeze(ok);
DCHECK(*ok);
interface->Unify(scope->interface(), zone(), ok);
DCHECK(*ok);
return result;
}
Module* Parser::ParseModuleSpecifier(bool* ok) {
// ModuleSpecifier:
// String
// ModulePath
if (peek() == Token::STRING) {
return ParseModuleUrl(ok);
} else {
return ParseModulePath(ok);
}
}
Block* Parser::ParseImportDeclaration(bool* ok) {
// ImportDeclaration:
// 'import' IdentifierName (',' IdentifierName)* 'from' ModuleSpecifier ';'
//
// TODO(ES6): implement destructuring ImportSpecifiers
int pos = peek_position();
Expect(Token::IMPORT, CHECK_OK);
ZoneList<const AstRawString*> names(1, zone());
const AstRawString* name = ParseIdentifierName(CHECK_OK);
names.Add(name, zone());
while (peek() == Token::COMMA) {
Consume(Token::COMMA);
name = ParseIdentifierName(CHECK_OK);
names.Add(name, zone());
}
ExpectContextualKeyword(CStrVector("from"), CHECK_OK);
Module* module = ParseModuleSpecifier(CHECK_OK);
ExpectSemicolon(CHECK_OK);
// Generate a separate declaration for each identifier.
// TODO(ES6): once we implement destructuring, make that one declaration.
Block* block = factory()->NewBlock(NULL, 1, true, RelocInfo::kNoPosition);
for (int i = 0; i < names.length(); ++i) {
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Import %.*s ", name->length(), name->raw_data());
#endif
Interface* interface = Interface::NewUnknown(zone());
module->interface()->Add(names[i], interface, zone(), ok);
if (!*ok) {
#ifdef DEBUG
if (FLAG_print_interfaces) {
PrintF("IMPORT TYPE ERROR at '%.*s'\n", name->length(),
name->raw_data());
PrintF("module: ");
module->interface()->Print();
}
#endif
ParserTraits::ReportMessage("invalid_module_path", name);
return NULL;
}
VariableProxy* proxy = NewUnresolved(names[i], LET, interface);
Declaration* declaration =
factory()->NewImportDeclaration(proxy, module, scope_, pos);
Declare(declaration, true, CHECK_OK);
}
return block;
}
Statement* Parser::ParseExportDeclaration(bool* ok) {
// ExportDeclaration:
// 'export' Identifier (',' Identifier)* ';'
// 'export' VariableDeclaration
// 'export' FunctionDeclaration
// 'export' GeneratorDeclaration
// 'export' ModuleDeclaration
//
// TODO(ES6): implement structuring ExportSpecifiers
Expect(Token::EXPORT, CHECK_OK);
Statement* result = NULL;
ZoneList<const AstRawString*> names(1, zone());
switch (peek()) {
case Token::IDENTIFIER: {
int pos = position();
const AstRawString* name =
ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
// Handle 'module' as a context-sensitive keyword.
if (name != ast_value_factory()->module_string()) {
names.Add(name, zone());
while (peek() == Token::COMMA) {
Consume(Token::COMMA);
name = ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
names.Add(name, zone());
}
ExpectSemicolon(CHECK_OK);
result = factory()->NewEmptyStatement(pos);
} else {
result = ParseModuleDeclaration(&names, CHECK_OK);
}
break;
}
case Token::FUNCTION:
result = ParseFunctionDeclaration(&names, CHECK_OK);
break;
case Token::CLASS:
result = ParseClassDeclaration(&names, CHECK_OK);
break;
case Token::VAR:
case Token::LET:
case Token::CONST:
result = ParseVariableStatement(kModuleElement, &names, CHECK_OK);
break;
default:
*ok = false;
ReportUnexpectedToken(scanner()->current_token());
return NULL;
}
// Every export of a module may be assigned.
for (int i = 0; i < names.length(); ++i) {
Variable* var = scope_->Lookup(names[i]);
if (var == NULL) {
// TODO(sigurds) This is an export that has no definition yet,
// not clear what to do in this case.
continue;
}
if (!IsImmutableVariableMode(var->mode())) {
var->set_maybe_assigned();
}
}
// Extract declared names into export declarations and interface.
Interface* interface = scope_->interface();
for (int i = 0; i < names.length(); ++i) {
#ifdef DEBUG
if (FLAG_print_interface_details)
PrintF("# Export %.*s ", names[i]->length(), names[i]->raw_data());
#endif
Interface* inner = Interface::NewUnknown(zone());
interface->Add(names[i], inner, zone(), CHECK_OK);
if (!*ok)
return NULL;
VariableProxy* proxy = NewUnresolved(names[i], LET, inner);
USE(proxy);
// TODO(rossberg): Rethink whether we actually need to store export
// declarations (for compilation?).
// ExportDeclaration* declaration =
// factory()->NewExportDeclaration(proxy, scope_, position);
// scope_->AddDeclaration(declaration);
}
DCHECK(result != NULL);
return result;
}
Statement* Parser::ParseBlockElement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// (Ecma 262 5th Edition, clause 14):
// SourceElement:
// Statement
// FunctionDeclaration
//
// In harmony mode we allow additionally the following productions
// BlockElement (aka SourceElement):
// LetDeclaration
// ConstDeclaration
// GeneratorDeclaration
// ClassDeclaration
switch (peek()) {
case Token::FUNCTION:
return ParseFunctionDeclaration(NULL, ok);
case Token::CLASS:
return ParseClassDeclaration(NULL, ok);
case Token::CONST:
return ParseVariableStatement(kModuleElement, NULL, ok);
case Token::LET:
DCHECK(allow_harmony_scoping());
if (strict_mode() == STRICT) {
return ParseVariableStatement(kModuleElement, NULL, ok);
}
// Fall through.
default:
return ParseStatement(labels, ok);
}
}
Statement* Parser::ParseStatement(ZoneList<const AstRawString*>* labels,
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:
return ParseContinueStatement(ok);
case Token::BREAK:
return ParseBreakStatement(labels, ok);
case Token::RETURN:
return ParseReturnStatement(ok);
case Token::WITH:
return ParseWithStatement(labels, ok);
case Token::SWITCH:
return ParseSwitchStatement(labels, ok);
case Token::THROW:
return ParseThrowStatement(ok);
case Token::TRY: {
// NOTE: It is somewhat complicated to have labels on
// try-statements. When breaking out of a try-finally statement,
// one must take great care not to treat it as a
// fall-through. It is much easier just to wrap the entire
// try-statement in a statement block and put the labels there
Block* result =
factory()->NewBlock(labels, 1, false, RelocInfo::kNoPosition);
Target target(&this->target_stack_, result);
TryStatement* statement = ParseTryStatement(CHECK_OK);
if (result) result->AddStatement(statement, zone());
return result;
}
case Token::FUNCTION: {
// FunctionDeclaration is only allowed in the context of SourceElements
// (Ecma 262 5th Edition, clause 14):
// SourceElement:
// Statement
// FunctionDeclaration
// Common language extension is to allow function declaration in place
// of any statement. This language extension is disabled in strict mode.
//
// In Harmony mode, this case also handles the extension:
// Statement:
// GeneratorDeclaration
if (strict_mode() == STRICT) {
ReportMessageAt(scanner()->peek_location(), "strict_function");
*ok = false;
return NULL;
}
return ParseFunctionDeclaration(NULL, ok);
}
case Token::CLASS:
return ParseClassDeclaration(NULL, ok);
case Token::DEBUGGER:
return ParseDebuggerStatement(ok);
case Token::VAR:
case Token::CONST:
return ParseVariableStatement(kStatement, NULL, ok);
case Token::LET:
DCHECK(allow_harmony_scoping());
if (strict_mode() == STRICT) {
return ParseVariableStatement(kStatement, NULL, ok);
}
// Fall through.
default:
return ParseExpressionOrLabelledStatement(labels, ok);
}
}
VariableProxy* Parser::NewUnresolved(const AstRawString* name,
VariableMode mode, Interface* interface) {
// 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.
return DeclarationScope(mode)->NewUnresolved(
factory(), name, interface, position());
}
void Parser::Declare(Declaration* declaration, bool resolve, bool* ok) {
VariableProxy* proxy = declaration->proxy();
DCHECK(proxy->raw_name() != NULL);
const AstRawString* name = proxy->raw_name();
VariableMode mode = declaration->mode();
Scope* declaration_scope = DeclarationScope(mode);
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 declarations inside an eval scope need to be added
// to the calling function context.
// Similarly, strict mode eval scope does not leak variable declarations to
// the caller's scope so we declare all locals, too.
if (declaration_scope->is_function_scope() ||
declaration_scope->is_strict_eval_scope() ||
declaration_scope->is_block_scope() ||
declaration_scope->is_module_scope() ||
declaration_scope->is_global_scope()) {
// Declare the variable in the declaration scope.
// For the global scope, we have to check for collisions with earlier
// (i.e., enclosing) global scopes, to maintain the illusion of a single
// global scope.
var = declaration_scope->is_global_scope()
? declaration_scope->Lookup(name)
: declaration_scope->LookupLocal(name);
if (var == NULL) {
// Declare the name.
var = declaration_scope->DeclareLocal(name, mode,
declaration->initialization(),
kNotAssigned, proxy->interface());
} else if (IsLexicalVariableMode(mode) || IsLexicalVariableMode(var->mode())
|| ((mode == CONST_LEGACY || var->mode() == CONST_LEGACY) &&
!declaration_scope->is_global_scope())) {
// 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 the global 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()));
if (allow_harmony_scoping() && strict_mode() == STRICT) {
// In harmony we treat re-declarations as early errors. See
// ES5 16 for a definition of early errors.
ParserTraits::ReportMessage("var_redeclaration", name);
*ok = false;
return;
}
Expression* expression = NewThrowTypeError(
"var_redeclaration", name, declaration->position());
declaration_scope->SetIllegalRedeclaration(expression);
} else if (mode == VAR) {
var->set_maybe_assigned();
}
}
// 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 (mode == CONST_LEGACY && declaration_scope->is_global_scope()) {
// For global const variables we bind the proxy to a variable.
DCHECK(resolve); // should be set by all callers
Variable::Kind kind = Variable::NORMAL;
var = new (zone())
Variable(declaration_scope, name, mode, true, kind,
kNeedsInitialization, kNotAssigned, proxy->interface());
} else if (declaration_scope->is_eval_scope() &&
declaration_scope->strict_mode() == SLOPPY) {
// For variable declarations in a sloppy eval scope 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, true, kind,
declaration->initialization(), kNotAssigned,
proxy->interface());
var->AllocateTo(Variable::LOOKUP, -1);
resolve = true;
}
// 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);
if (FLAG_harmony_modules) {
bool ok;
#ifdef DEBUG
if (FLAG_print_interface_details) {
PrintF("# Declare %.*s ", var->raw_name()->length(),
var->raw_name()->raw_data());
}
#endif
proxy->interface()->Unify(var->interface(), zone(), &ok);
if (!ok) {
#ifdef DEBUG
if (FLAG_print_interfaces) {
PrintF("DECLARE TYPE ERROR\n");
PrintF("proxy: ");
proxy->interface()->Print();
PrintF("var: ");
var->interface()->Print();
}
#endif
ParserTraits::ReportMessage("module_type_error", name);
}
}
}
}
// 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(kAllowEvalOrArguments, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
bool done = (peek() == Token::RPAREN);
while (!done) {
ParseIdentifier(kAllowEvalOrArguments, 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.
DeclarationScope(VAR)->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, Interface::NewValue());
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, VAR, scope_, pos);
Declare(declaration, true, CHECK_OK);
NativeFunctionLiteral* lit = factory()->NewNativeFunctionLiteral(
name, extension_, RelocInfo::kNoPosition);
return factory()->NewExpressionStatement(
factory()->NewAssignment(
Token::INIT_VAR, proxy, lit, RelocInfo::kNoPosition),
pos);
}
Statement* Parser::ParseFunctionDeclaration(
ZoneList<const AstRawString*>* names, bool* ok) {
// FunctionDeclaration ::
// 'function' Identifier '(' FormalParameterListopt ')' '{' FunctionBody '}'
// GeneratorDeclaration ::
// 'function' '*' Identifier '(' FormalParameterListopt ')'
// '{' FunctionBody '}'
Expect(Token::FUNCTION, CHECK_OK);
int pos = position();
bool is_generator = Check(Token::MUL);
bool is_strict_reserved = false;
const AstRawString* name = ParseIdentifierOrStrictReservedWord(
&is_strict_reserved, CHECK_OK);
FunctionLiteral* fun =
ParseFunctionLiteral(name, scanner()->location(), is_strict_reserved,
is_generator ? FunctionKind::kGeneratorFunction
: FunctionKind::kNormalFunction,
pos, FunctionLiteral::DECLARATION,
FunctionLiteral::NORMAL_ARITY, 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 the
// global scope, or the initial scope of eval or another function.
VariableMode mode =
allow_harmony_scoping() && strict_mode() == STRICT &&
!(scope_->is_global_scope() || scope_->is_eval_scope() ||
scope_->is_function_scope()) ? LET : VAR;
VariableProxy* proxy = NewUnresolved(name, mode, Interface::NewValue());
Declaration* declaration =
factory()->NewFunctionDeclaration(proxy, mode, fun, scope_, pos);
Declare(declaration, true, CHECK_OK);
if (names) names->Add(name, zone());
return factory()->NewEmptyStatement(RelocInfo::kNoPosition);
}
Statement* Parser::ParseClassDeclaration(ZoneList<const AstRawString*>* names,
bool* ok) {
// ClassDeclaration ::
// 'class' Identifier ('extends' LeftHandExpression)? '{' ClassBody '}'
//
// A ClassDeclaration
//
// class C { ... }
//
// has the same semantics as:
//
// let C = class C { ... };
//
// so rewrite it as such.
Expect(Token::CLASS, CHECK_OK);
int pos = position();
bool is_strict_reserved = false;
const AstRawString* name =
ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
Expression* value = ParseClassLiteral(name, scanner()->location(),
is_strict_reserved, pos, CHECK_OK);
VariableProxy* proxy = NewUnresolved(name, LET, Interface::NewValue());
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, LET, scope_, pos);
Declare(declaration, true, CHECK_OK);
proxy->var()->set_initializer_position(pos);
Token::Value init_op = Token::INIT_LET;
Assignment* assignment = factory()->NewAssignment(init_op, 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* ok) {
if (allow_harmony_scoping() && strict_mode() == STRICT) {
return ParseScopedBlock(labels, ok);
}
// Block ::
// '{' Statement* '}'
// Note that a Block does not introduce a new execution scope!
// (ECMA-262, 3rd, 12.2)
//
// Construct block expecting 16 statements.
Block* result =
factory()->NewBlock(labels, 16, false, RelocInfo::kNoPosition);
Target target(&this->target_stack_, result);
Expect(Token::LBRACE, CHECK_OK);
while (peek() != Token::RBRACE) {
Statement* stat = ParseStatement(NULL, CHECK_OK);
if (stat && !stat->IsEmpty()) {
result->AddStatement(stat, zone());
}
}
Expect(Token::RBRACE, CHECK_OK);
return result;
}
Block* Parser::ParseScopedBlock(ZoneList<const AstRawString*>* labels,
bool* ok) {
// The harmony mode uses block elements instead of statements.
//
// Block ::
// '{' BlockElement* '}'
// 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);
TargetCollector collector(zone());
Target target(&this->target_stack_, &collector);
Target target_body(&this->target_stack_, body);
while (peek() != Token::RBRACE) {
Statement* stat = ParseBlockElement(NULL, CHECK_OK);
if (stat && !stat->IsEmpty()) {
body->AddStatement(stat, zone());
}
}
}
Expect(Token::RBRACE, CHECK_OK);
block_scope->set_end_position(scanner()->location().end_pos);
block_scope = block_scope->FinalizeBlockScope();
body->set_scope(block_scope);
return body;
}
Block* Parser::ParseVariableStatement(VariableDeclarationContext var_context,
ZoneList<const AstRawString*>* names,
bool* ok) {
// VariableStatement ::
// VariableDeclarations ';'
const AstRawString* ignore;
Block* result =
ParseVariableDeclarations(var_context, NULL, names, &ignore, CHECK_OK);
ExpectSemicolon(CHECK_OK);
return result;
}
// If the variable declaration declares exactly one non-const
// variable, then *out is set to that variable. In all other cases,
// *out is untouched; in particular, it is the caller's responsibility
// to initialize it properly. This mechanism is used for the parsing
// of 'for-in' loops.
Block* Parser::ParseVariableDeclarations(
VariableDeclarationContext var_context,
VariableDeclarationProperties* decl_props,
ZoneList<const AstRawString*>* names,
const AstRawString** out,
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
int pos = peek_position();
VariableMode mode = VAR;
// True if the binding needs initialization. 'let' and 'const' declared
// bindings are created uninitialized by their declaration nodes and
// need initialization. 'var' declared bindings are always initialized
// immediately by their declaration nodes.
bool needs_init = false;
bool is_const = false;
Token::Value init_op = Token::INIT_VAR;
if (peek() == Token::VAR) {
Consume(Token::VAR);
} else if (peek() == Token::CONST) {
// TODO(ES6): The ES6 Draft Rev4 section 12.2.2 reads:
//
// ConstDeclaration : const ConstBinding (',' ConstBinding)* ';'
//
// * It is a Syntax Error if the code that matches this production is not
// contained in extended code.
//
// However disallowing const in sloppy mode will break compatibility with
// existing pages. Therefore we keep allowing const with the old
// non-harmony semantics in sloppy mode.
Consume(Token::CONST);
switch (strict_mode()) {
case SLOPPY:
mode = CONST_LEGACY;
init_op = Token::INIT_CONST_LEGACY;
break;
case STRICT:
if (allow_harmony_scoping()) {
if (var_context == kStatement) {
// In strict mode 'const' declarations are only allowed in source
// element positions.
ReportMessage("unprotected_const");
*ok = false;
return NULL;
}
mode = CONST;
init_op = Token::INIT_CONST;
} else {
ReportMessage("strict_const");
*ok = false;
return NULL;
}
}
is_const = true;
needs_init = true;
} else if (peek() == Token::LET && strict_mode() == STRICT) {
DCHECK(allow_harmony_scoping());
Consume(Token::LET);
if (var_context == kStatement) {
// Let declarations are only allowed in source element positions.
ReportMessage("unprotected_let");
*ok = false;
return NULL;
}
mode = LET;
needs_init = true;
init_op = Token::INIT_LET;
} else {
UNREACHABLE(); // by current callers
}
Scope* declaration_scope = DeclarationScope(mode);
// 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.
//
// Create new block with one expected declaration.
Block* block = factory()->NewBlock(NULL, 1, true, pos);
int nvars = 0; // the number of variables declared
const AstRawString* name = NULL;
bool is_for_iteration_variable;
do {
if (fni_ != NULL) fni_->Enter();
// Parse variable name.
if (nvars > 0) Consume(Token::COMMA);
name = ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
if (fni_ != NULL) fni_->PushVariableName(name);
// Declare variable.
// Note that we *always* must treat the initial value via a separate init
// assignment for variables and constants because the value must be assigned
// when the variable is encountered in the source. But the variable/constant
// is declared (and set to 'undefined') upon entering the function within
// which the variable or constant is declared. Only function variables have
// an initial value in the declaration (because they are initialized upon
// entering the function).
//
// If we have a const declaration, in an inner scope, the proxy is always
// bound to the declared variable (independent of possibly surrounding with
// statements).
// For let/const declarations in harmony mode, we can also immediately
// pre-resolve the proxy because it resides in the same scope as the
// declaration.
is_for_iteration_variable =
var_context == kForStatement &&
(peek() == Token::IN || PeekContextualKeyword(CStrVector("of")));
if (is_for_iteration_variable && mode == CONST) {
needs_init = false;
}
Interface* interface =
is_const ? Interface::NewConst() : Interface::NewValue();
VariableProxy* proxy = NewUnresolved(name, mode, interface);
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, mode, scope_, pos);
Declare(declaration, mode != VAR, CHECK_OK);
nvars++;
if (declaration_scope->num_var_or_const() > kMaxNumFunctionLocals) {
ReportMessage("too_many_variables");
*ok = false;
return NULL;
}
if (names) names->Add(name, zone());
// Parse initialization expression if present and/or needed. A
// declaration of the form:
//
// var v = x;
//
// is syntactic sugar for:
//
// var v; v = x;
//
// In particular, we need to re-lookup 'v' (in scope_, not
// declaration_scope) as it may be a different 'v' than the 'v' in the
// declaration (e.g., if we are inside a 'with' statement or 'catch'
// block).
//
// However, note that const declarations are different! A const
// declaration of the form:
//
// const c = x;
//
// is *not* syntactic sugar for:
//
// const c; c = x;
//
// The "variable" c initialized to x is the same as the declared
// one - there is no re-lookup (see the last parameter of the
// Declare() call above).
Scope* initialization_scope = is_const ? declaration_scope : scope_;
Expression* value = NULL;
int pos = -1;
// Harmony consts have non-optional initializers.
if (peek() == Token::ASSIGN ||
(mode == CONST && !is_for_iteration_variable)) {
Expect(Token::ASSIGN, CHECK_OK);
pos = position();
value = ParseAssignmentExpression(var_context != kForStatement, CHECK_OK);
// Don't infer if it is "a = function(){...}();"-like expression.
if (fni_ != NULL &&
value->AsCall() == NULL &&
value->AsCallNew() == NULL) {
fni_->Infer();
} else {
fni_->RemoveLastFunction();
}
if (decl_props != NULL) *decl_props = kHasInitializers;
}
// Record the end position of the initializer.
if (proxy->is_resolved()) {
proxy->var()->set_initializer_position(position());
}
// Make sure that 'const x' and 'let x' initialize 'x' to undefined.
if (value == NULL && needs_init) {
value = GetLiteralUndefined(position());
}
// Global variable declarations must be compiled in a specific
// way. When the script containing the global variable declaration
// is entered, the global variable must be declared, so that if it
// doesn't exist (on the global object itself, see ES5 errata) it
// gets created with an initial undefined value. This is handled
// by the declarations part of the function representing the
// top-level global code; see Runtime::DeclareGlobalVariable. If
// it already exists (in the object or in a prototype), it is
// *not* touched until the variable declaration statement is
// executed.
//
// Executing the variable declaration statement will always
// guarantee to give the global object an own property.
// This way, global variable declarations can shadow
// properties in the prototype chain, but only after the variable
// declaration statement has been executed. This is important in
// browsers where the global object (window) has lots of
// properties defined in prototype objects.
if (initialization_scope->is_global_scope() &&
!IsLexicalVariableMode(mode)) {
// Compute the arguments for the runtime call.
ZoneList<Expression*>* arguments =
new(zone()) ZoneList<Expression*>(3, zone());
// We have at least 1 parameter.
arguments->Add(factory()->NewStringLiteral(name, pos), zone());
CallRuntime* initialize;
if (is_const) {
arguments->Add(value, zone());
value = NULL; // zap the value to avoid the unnecessary assignment
// Construct the call to Runtime_InitializeConstGlobal
// and add it to the initialization statement block.
// Note that the function does different things depending on
// the number of arguments (1 or 2).
initialize = factory()->NewCallRuntime(
ast_value_factory()->initialize_const_global_string(),
Runtime::FunctionForId(Runtime::kInitializeConstGlobal), arguments,
pos);
} else {
// Add strict mode.
// We may want to pass singleton to avoid Literal allocations.
StrictMode strict_mode = initialization_scope->strict_mode();
arguments->Add(factory()->NewNumberLiteral(strict_mode, pos), zone());
// Be careful not to assign a value to the global variable if
// we're in a with. The initialization value should not
// necessarily be stored in the global object in that case,
// which is why we need to generate a separate assignment node.
if (value != NULL && !inside_with()) {
arguments->Add(value, zone());
value = NULL; // zap the value to avoid the unnecessary assignment
// Construct the call to Runtime_InitializeVarGlobal
// and add it to the initialization statement block.
initialize = factory()->NewCallRuntime(
ast_value_factory()->initialize_var_global_string(),
Runtime::FunctionForId(Runtime::kInitializeVarGlobal), arguments,
pos);
} else {
initialize = NULL;
}
}
if (initialize != NULL) {
block->AddStatement(factory()->NewExpressionStatement(
initialize, RelocInfo::kNoPosition),
zone());
}
} else if (needs_init) {
// Constant initializations always assign to the declared constant which
// is always at the function scope level. This is only relevant for
// dynamically looked-up variables and constants (the start context for
// constant lookups is always the function context, while it is the top
// context for var declared variables). Sigh...
// For 'let' and 'const' declared variables in harmony mode the
// initialization also always assigns to the declared variable.
DCHECK(proxy != NULL);
DCHECK(proxy->var() != NULL);
DCHECK(value != NULL);
Assignment* assignment =
factory()->NewAssignment(init_op, proxy, value, pos);
block->AddStatement(
factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition),
zone());
value = NULL;
}
// Add an assignment node to the initialization statement block if we still
// have a pending initialization value.
if (value != NULL) {
DCHECK(mode == VAR);
// 'var' initializations are simply assignments (with all the consequences
// if they are inside a 'with' statement - they may change a 'with' object
// property).
VariableProxy* proxy =
initialization_scope->NewUnresolved(factory(), name, interface);
Assignment* assignment =
factory()->NewAssignment(init_op, proxy, value, pos);
block->AddStatement(
factory()->NewExpressionStatement(assignment, RelocInfo::kNoPosition),
zone());
}
if (fni_ != NULL) fni_->Leave();
} while (peek() == Token::COMMA);
// If there was a single non-const declaration, return it in the output
// parameter for possible use by for/in.
if (nvars == 1 && (!is_const || is_for_iteration_variable)) {
*out = name;
}
return 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::ParseExpressionOrLabelledStatement(
ZoneList<const AstRawString*>* labels, bool* ok) {
// ExpressionStatement | LabelledStatement ::
// Expression ';'
// Identifier ':' Statement
int pos = peek_position();
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("label_redeclaration", 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);
return ParseStatement(labels, 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, or the context-sensitive 'module' keyword.
// Only expect semicolon in the former case.
if (!FLAG_harmony_modules || peek() != Token::IDENTIFIER ||
scanner()->HasAnyLineTerminatorBeforeNext() ||
expr->AsVariableProxy() == NULL ||
expr->AsVariableProxy()->raw_name() !=
ast_value_factory()->module_string() ||
scanner()->literal_contains_escapes()) {
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 = ParseStatement(labels, CHECK_OK);
Statement* else_statement = NULL;
if (peek() == Token::ELSE) {
Next();
else_statement = ParseStatement(labels, 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(kAllowEvalOrArguments, CHECK_OK);
}
IterationStatement* target = LookupContinueTarget(label, CHECK_OK);
if (target == NULL) {
// Illegal continue statement.
const char* message = "illegal_continue";
if (label != NULL) {
message = "unknown_label";
}
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(kAllowEvalOrArguments, 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.
const char* message = "illegal_break";
if (label != NULL) {
message = "unknown_label";
}
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();
Token::Value tok = peek();
Statement* result;
Expression* return_value;
if (scanner()->HasAnyLineTerminatorBeforeNext() ||
tok == Token::SEMICOLON ||
tok == Token::RBRACE ||
tok == Token::EOS) {
return_value = GetLiteralUndefined(position());
} else {
return_value = ParseExpression(true, CHECK_OK);
}
ExpectSemicolon(CHECK_OK);
if (is_generator()) {
Expression* generator = factory()->NewVariableProxy(
function_state_->generator_object_variable());
Expression* yield = factory()->NewYield(
generator, return_value, Yield::kFinal, loc.beg_pos);
result = factory()->NewExpressionStatement(yield, loc.beg_pos);
} else {
result = factory()->NewReturnStatement(return_value, loc.beg_pos);
}
Scope* decl_scope = scope_->DeclarationScope();
if (decl_scope->is_global_scope() || decl_scope->is_eval_scope()) {
ReportMessageAt(loc, "illegal_return");
*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 (strict_mode() == STRICT) {
ReportMessage("strict_mode_with");
*ok = false;
return NULL;
}
Expect(Token::LPAREN, CHECK_OK);
Expression* expr = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
scope_->DeclarationScope()->RecordWithStatement();
Scope* with_scope = NewScope(scope_, WITH_SCOPE);
Statement* stmt;
{ BlockState block_state(&scope_, with_scope);
with_scope->set_start_position(scanner()->peek_location().beg_pos);
stmt = ParseStatement(labels, CHECK_OK);
with_scope->set_end_position(scanner()->location().end_pos);
}
return factory()->NewWithStatement(with_scope, expr, stmt, pos);
}
CaseClause* Parser::ParseCaseClause(bool* default_seen_ptr, bool* ok) {
// CaseClause ::
// 'case' Expression ':' Statement*
// 'default' ':' Statement*
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("multiple_defaults_in_switch");
*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());
while (peek() != Token::CASE &&
peek() != Token::DEFAULT &&
peek() != Token::RBRACE) {
Statement* stat = ParseStatement(NULL, CHECK_OK);
statements->Add(stat, zone());
}
return factory()->NewCaseClause(label, statements, pos);
}
SwitchStatement* Parser::ParseSwitchStatement(
ZoneList<const AstRawString*>* labels, bool* ok) {
// SwitchStatement ::
// 'switch' '(' Expression ')' '{' CaseClause* '}'
SwitchStatement* statement =
factory()->NewSwitchStatement(labels, peek_position());
Target target(&this->target_stack_, statement);
Expect(Token::SWITCH, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
Expression* tag = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
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());
}
Expect(Token::RBRACE, CHECK_OK);
if (statement) statement->Initialize(tag, cases);
return statement;
}
Statement* Parser::ParseThrowStatement(bool* ok) {
// ThrowStatement ::
// 'throw' Expression ';'
Expect(Token::THROW, CHECK_OK);
int pos = position();
if (scanner()->HasAnyLineTerminatorBeforeNext()) {
ReportMessage("newline_after_throw");
*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();
TargetCollector try_collector(zone());
Block* try_block;
{ Target target(&this->target_stack_, &try_collector);
try_block = ParseBlock(NULL, CHECK_OK);
}
Token::Value tok = peek();
if (tok != Token::CATCH && tok != Token::FINALLY) {
ReportMessage("no_catch_or_finally");
*ok = false;
return NULL;
}
// If we can break out from the catch block and there is a finally block,
// then we will need to collect escaping targets from the catch
// block. Since we don't know yet if there will be a finally block, we
// always collect the targets.
TargetCollector catch_collector(zone());
Scope* catch_scope = NULL;
Variable* catch_variable = NULL;
Block* catch_block = NULL;
const AstRawString* name = NULL;
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);
name = ParseIdentifier(kDontAllowEvalOrArguments, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Target target(&this->target_stack_, &catch_collector);
VariableMode mode =
allow_harmony_scoping() && strict_mode() == STRICT ? LET : VAR;
catch_variable = catch_scope->DeclareLocal(name, mode, kCreatedInitialized);
BlockState block_state(&scope_, catch_scope);
catch_block = ParseBlock(NULL, CHECK_OK);
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);
int index = function_state_->NextHandlerIndex();
TryCatchStatement* statement = factory()->NewTryCatchStatement(
index, try_block, catch_scope, catch_variable, catch_block,
RelocInfo::kNoPosition);
statement->set_escaping_targets(try_collector.targets());
try_block = factory()->NewBlock(NULL, 1, false, RelocInfo::kNoPosition);
try_block->AddStatement(statement, zone());
catch_block = NULL; // Clear to indicate it's been handled.
}
TryStatement* result = NULL;
if (catch_block != NULL) {
DCHECK(finally_block == NULL);
DCHECK(catch_scope != NULL && catch_variable != NULL);
int index = function_state_->NextHandlerIndex();
result = factory()->NewTryCatchStatement(
index, try_block, catch_scope, catch_variable, catch_block, pos);
} else {
DCHECK(finally_block != NULL);
int index = function_state_->NextHandlerIndex();
result = factory()->NewTryFinallyStatement(
index, try_block, finally_block, pos);
// Combine the jump targets of the try block and the possible catch block.
try_collector.targets()->AddAll(*catch_collector.targets(), zone());
}
result->set_escaping_targets(try_collector.targets());
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 = ParseStatement(NULL, 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 = ParseStatement(NULL, CHECK_OK);
if (loop != NULL) loop->Initialize(cond, body);
return loop;
}
bool Parser::CheckInOrOf(bool accept_OF,
ForEachStatement::VisitMode* visit_mode) {
if (Check(Token::IN)) {
*visit_mode = ForEachStatement::ENUMERATE;
return true;
} else if (accept_OF && CheckContextualKeyword(CStrVector("of"))) {
*visit_mode = ForEachStatement::ITERATE;
return true;
}
return false;
}
void Parser::InitializeForEachStatement(ForEachStatement* stmt,
Expression* each,
Expression* subject,
Statement* body) {
ForOfStatement* for_of = stmt->AsForOfStatement();
if (for_of != NULL) {
Variable* iterator = scope_->DeclarationScope()->NewTemporary(
ast_value_factory()->dot_iterator_string());
Variable* result = scope_->DeclarationScope()->NewTemporary(
ast_value_factory()->dot_result_string());
Expression* assign_iterator;
Expression* next_result;
Expression* result_done;
Expression* assign_each;
// var iterator = subject[Symbol.iterator]();
assign_iterator = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(iterator),
GetIterator(subject, factory()), RelocInfo::kNoPosition);
// var result = iterator.next();
{
Expression* iterator_proxy = factory()->NewVariableProxy(iterator);
Expression* next_literal = factory()->NewStringLiteral(
ast_value_factory()->next_string(), RelocInfo::kNoPosition);
Expression* next_property = factory()->NewProperty(
iterator_proxy, next_literal, RelocInfo::kNoPosition);
ZoneList<Expression*>* next_arguments =
new(zone()) ZoneList<Expression*>(0, zone());
Expression* next_call = factory()->NewCall(
next_property, next_arguments, RelocInfo::kNoPosition);
Expression* result_proxy = factory()->NewVariableProxy(result);
next_result = factory()->NewAssignment(
Token::ASSIGN, result_proxy, next_call, RelocInfo::kNoPosition);
}
// 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);
}
for_of->Initialize(each, subject, body,
assign_iterator,
next_result,
result_done,
assign_each);
} else {
stmt->Initialize(each, subject, body);
}
}
Statement* Parser::DesugarLetBindingsInForStatement(
Scope* inner_scope, ZoneList<const AstRawString*>* names,
ForStatement* loop, Statement* init, Expression* cond, Statement* next,
Statement* body, bool* ok) {
// ES6 13.6.3.4 specifies that on each loop iteration the let variables are
// copied into a new environment. After copying, the "next" statement of the
// loop is executed to update the loop variables. The loop condition is
// checked and the loop body is executed.
//
// We rewrite a for statement of the form
//
// for (let x = i; cond; next) body
//
// into
//
// {
// let x = i;
// temp_x = x;
// flag = 1;
// for (;;) {
// let x = temp_x;
// if (flag == 1) {
// flag = 0;
// } else {
// next;
// }
// if (cond) {
// <empty>
// } else {
// break;
// }
// b
// temp_x = x;
// }
// }
DCHECK(names->length() > 0);
Scope* for_scope = scope_;
ZoneList<Variable*> temps(names->length(), zone());
Block* outer_block = factory()->NewBlock(NULL, names->length() + 3, false,
RelocInfo::kNoPosition);
outer_block->AddStatement(init, zone());
const AstRawString* temp_name = ast_value_factory()->dot_for_string();
// For each let variable x:
// make statement: temp_x = x.
for (int i = 0; i < names->length(); i++) {
VariableProxy* proxy =
NewUnresolved(names->at(i), LET, Interface::NewValue());
Variable* temp = scope_->DeclarationScope()->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->AddStatement(assignment_statement, zone());
temps.Add(temp, zone());
}
Variable* flag = scope_->DeclarationScope()->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);
outer_block->AddStatement(assignment_statement, zone());
}
outer_block->AddStatement(loop, zone());
outer_block->set_scope(for_scope);
scope_ = inner_scope;
Block* inner_block = factory()->NewBlock(NULL, 2 * names->length() + 3,
false, RelocInfo::kNoPosition);
int pos = scanner()->location().beg_pos;
ZoneList<Variable*> inner_vars(names->length(), zone());
// For each let variable x:
// make statement: let x = temp_x.
for (int i = 0; i < names->length(); i++) {
VariableProxy* proxy =
NewUnresolved(names->at(i), LET, Interface::NewValue());
Declaration* declaration =
factory()->NewVariableDeclaration(proxy, LET, scope_, pos);
Declare(declaration, true, CHECK_OK);
inner_vars.Add(declaration->proxy()->var(), zone());
VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i));
Assignment* assignment = factory()->NewAssignment(
Token::INIT_LET, proxy, temp_proxy, pos);
Statement* assignment_statement = factory()->NewExpressionStatement(
assignment, pos);
proxy->var()->set_initializer_position(pos);
inner_block->AddStatement(assignment_statement, zone());
}
// Make statement: if (flag == 1) { flag = 0; } else { next; }.
if (next) {
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, pos);
}
Statement* clear_flag = NULL;
// Make statement: flag = 0.
{
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
Expression* const0 = factory()->NewSmiLiteral(0, RelocInfo::kNoPosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, flag_proxy, const0, RelocInfo::kNoPosition);
clear_flag = factory()->NewExpressionStatement(assignment, pos);
}
Statement* clear_flag_or_next = factory()->NewIfStatement(
compare, clear_flag, next, RelocInfo::kNoPosition);
inner_block->AddStatement(clear_flag_or_next, zone());
}
// Make statement: if (cond) { } else { break; }.
if (cond) {
Statement* empty = factory()->NewEmptyStatement(RelocInfo::kNoPosition);
BreakableStatement* t = LookupBreakTarget(NULL, CHECK_OK);
Statement* stop = factory()->NewBreakStatement(t, RelocInfo::kNoPosition);
Statement* if_not_cond_break = factory()->NewIfStatement(
cond, empty, stop, cond->position());
inner_block->AddStatement(if_not_cond_break, zone());
}
inner_block->AddStatement(body, zone());
// For each let variable x:
// make statement: temp_x = x;
for (int i = 0; i < names->length(); i++) {
VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i));
int pos = scanner()->location().end_pos;
VariableProxy* proxy = factory()->NewVariableProxy(inner_vars.at(i), pos);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, temp_proxy, proxy, RelocInfo::kNoPosition);
Statement* assignment_statement = factory()->NewExpressionStatement(
assignment, RelocInfo::kNoPosition);
inner_block->AddStatement(assignment_statement, zone());
}
inner_scope->set_end_position(scanner()->location().end_pos);
inner_block->set_scope(inner_scope);
scope_ = for_scope;
loop->Initialize(NULL, NULL, NULL, inner_block);
return outer_block;
}
Statement* Parser::ParseForStatement(ZoneList<const AstRawString*>* labels,
bool* ok) {
// ForStatement ::
// 'for' '(' Expression? ';' Expression? ';' Expression? ')' Statement
int pos = peek_position();
Statement* init = NULL;
ZoneList<const AstRawString*> let_bindings(1, zone());
// Create an in-between scope for let-bound iteration variables.
Scope* saved_scope = scope_;
Scope* for_scope = NewScope(scope_, BLOCK_SCOPE);
scope_ = for_scope;
Expect(Token::FOR, CHECK_OK);
Expect(Token::LPAREN, CHECK_OK);
for_scope->set_start_position(scanner()->location().beg_pos);
if (peek() != Token::SEMICOLON) {
if (peek() == Token::VAR ||
(peek() == Token::CONST && strict_mode() == SLOPPY)) {
bool is_const = peek() == Token::CONST;
const AstRawString* name = NULL;
VariableDeclarationProperties decl_props = kHasNoInitializers;
Block* variable_statement =
ParseVariableDeclarations(kForStatement, &decl_props, NULL, &name,
CHECK_OK);
bool accept_OF = decl_props == kHasNoInitializers;
ForEachStatement::VisitMode mode;
if (name != NULL && CheckInOrOf(accept_OF, &mode)) {
Interface* interface =
is_const ? Interface::NewConst() : Interface::NewValue();
ForEachStatement* loop =
factory()->NewForEachStatement(mode, labels, pos);
Target target(&this->target_stack_, loop);
Expression* enumerable = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
VariableProxy* each =
scope_->NewUnresolved(factory(), name, interface);
Statement* body = ParseStatement(NULL, CHECK_OK);
InitializeForEachStatement(loop, each, enumerable, body);
Block* result =
factory()->NewBlock(NULL, 2, false, RelocInfo::kNoPosition);
result->AddStatement(variable_statement, zone());
result->AddStatement(loop, zone());
scope_ = saved_scope;
for_scope->set_end_position(scanner()->location().end_pos);
for_scope = for_scope->FinalizeBlockScope();
DCHECK(for_scope == NULL);
// Parsed for-in loop w/ variable/const declaration.
return result;
} else {
init = variable_statement;
}
} else if ((peek() == Token::LET || peek() == Token::CONST) &&
strict_mode() == STRICT) {
bool is_const = peek() == Token::CONST;
const AstRawString* name = NULL;
VariableDeclarationProperties decl_props = kHasNoInitializers;
Block* variable_statement =
ParseVariableDeclarations(kForStatement, &decl_props, &let_bindings,
&name, CHECK_OK);
bool accept_IN = name != NULL && decl_props != kHasInitializers;
bool accept_OF = decl_props == kHasNoInitializers;
ForEachStatement::VisitMode mode;
if (accept_IN && CheckInOrOf(accept_OF, &mode)) {
// Rewrite a for-in statement of the form
//
// for (let/const x in e) b
//
// into
//
// <let x' be a temporary variable>
// for (x' in e) {
// let/const x;
// x = x';
// b;
// }
// TODO(keuchel): Move the temporary variable to the block scope, after
// implementing stack allocated block scoped variables.
Variable* temp = scope_->DeclarationScope()->NewTemporary(
ast_value_factory()->dot_for_string());
VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);
ForEachStatement* loop =
factory()->NewForEachStatement(mode, labels, pos);
Target target(&this->target_stack_, loop);
// The expression does not see the loop variable.
scope_ = saved_scope;
Expression* enumerable = ParseExpression(true, CHECK_OK);
scope_ = for_scope;
Expect(Token::RPAREN, CHECK_OK);
VariableProxy* each = scope_->NewUnresolved(factory(), name);
Statement* body = ParseStatement(NULL, CHECK_OK);
Block* body_block =
factory()->NewBlock(NULL, 3, false, RelocInfo::kNoPosition);
Token::Value init_op = is_const ? Token::INIT_CONST : Token::ASSIGN;
Assignment* assignment = factory()->NewAssignment(
init_op, each, temp_proxy, RelocInfo::kNoPosition);
Statement* assignment_statement = factory()->NewExpressionStatement(
assignment, RelocInfo::kNoPosition);
body_block->AddStatement(variable_statement, zone());
body_block->AddStatement(assignment_statement, zone());
body_block->AddStatement(body, zone());
InitializeForEachStatement(loop, temp_proxy, enumerable, body_block);
scope_ = saved_scope;
for_scope->set_end_position(scanner()->location().end_pos);
for_scope = for_scope->FinalizeBlockScope();
body_block->set_scope(for_scope);
// Parsed for-in loop w/ let declaration.
return loop;
} else {
init = variable_statement;
}
} else {
Scanner::Location lhs_location = scanner()->peek_location();
Expression* expression = ParseExpression(false, CHECK_OK);
ForEachStatement::VisitMode mode;
bool accept_OF = expression->IsVariableProxy();
if (CheckInOrOf(accept_OF, &mode)) {
expression = this->CheckAndRewriteReferenceExpression(
expression, lhs_location, "invalid_lhs_in_for", CHECK_OK);
ForEachStatement* loop =
factory()->NewForEachStatement(mode, labels, pos);
Target target(&this->target_stack_, loop);
Expression* enumerable = ParseExpression(true, CHECK_OK);
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
InitializeForEachStatement(loop, expression, enumerable, body);
scope_ = saved_scope;
for_scope->set_end_position(scanner()->location().end_pos);
for_scope = for_scope->FinalizeBlockScope();
DCHECK(for_scope == NULL);
// Parsed for-in loop.
return loop;
} else {
init = factory()->NewExpressionStatement(
expression, RelocInfo::kNoPosition);
}
}
}
// Standard 'for' loop
ForStatement* loop = factory()->NewForStatement(labels, pos);
Target target(&this->target_stack_, loop);
// Parsed initializer at this point.
Expect(Token::SEMICOLON, CHECK_OK);
// 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 = NULL;
if (let_bindings.length() > 0) {
inner_scope = NewScope(for_scope, BLOCK_SCOPE);
inner_scope->set_start_position(scanner()->location().beg_pos);
scope_ = inner_scope;
}
Expression* cond = NULL;
if (peek() != Token::SEMICOLON) {
cond = ParseExpression(true, CHECK_OK);
}
Expect(Token::SEMICOLON, CHECK_OK);
Statement* next = NULL;
if (peek() != Token::RPAREN) {
Expression* exp = ParseExpression(true, CHECK_OK);
next = factory()->NewExpressionStatement(exp, RelocInfo::kNoPosition);
}
Expect(Token::RPAREN, CHECK_OK);
Statement* body = ParseStatement(NULL, CHECK_OK);
Statement* result = NULL;
if (let_bindings.length() > 0) {
scope_ = for_scope;
result = DesugarLetBindingsInForStatement(inner_scope, &let_bindings, loop,
init, cond, next, body, CHECK_OK);
scope_ = saved_scope;
for_scope->set_end_position(scanner()->location().end_pos);
} else {
scope_ = saved_scope;
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
// }
DCHECK(init != NULL);
Block* block =
factory()->NewBlock(NULL, 2, false, RelocInfo::kNoPosition);
block->AddStatement(init, zone());
block->AddStatement(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)));
}
bool CheckAndDeclareArrowParameter(ParserTraits* traits, Expression* expression,
Scope* scope, int* num_params,
Scanner::Location* dupe_loc) {
// Case for empty parameter lists:
// () => ...
if (expression == NULL) return true;
// Too many parentheses around expression:
// (( ... )) => ...
if (expression->is_multi_parenthesized()) return false;
// Case for a single parameter:
// (foo) => ...
// foo => ...
if (expression->IsVariableProxy()) {
if (expression->AsVariableProxy()->is_this()) return false;
const AstRawString* raw_name = expression->AsVariableProxy()->raw_name();
if (traits->IsEvalOrArguments(raw_name) ||
traits->IsFutureStrictReserved(raw_name))
return false;
if (scope->IsDeclared(raw_name)) {
*dupe_loc = Scanner::Location(
expression->position(), expression->position() + raw_name->length());
return false;
}
scope->DeclareParameter(raw_name, VAR);
++(*num_params);
return true;
}
// Case for more than one parameter:
// (foo, bar [, ...]) => ...
if (expression->IsBinaryOperation()) {
BinaryOperation* binop = expression->AsBinaryOperation();
if (binop->op() != Token::COMMA || binop->left()->is_parenthesized() ||
binop->right()->is_parenthesized())
return false;
return CheckAndDeclareArrowParameter(traits, binop->left(), scope,
num_params, dupe_loc) &&
CheckAndDeclareArrowParameter(traits, binop->right(), scope,
num_params, dupe_loc);
}
// Any other kind of expression is not a valid parameter list.
return false;
}
int ParserTraits::DeclareArrowParametersFromExpression(
Expression* expression, Scope* scope, Scanner::Location* dupe_loc,
bool* ok) {
int num_params = 0;
*ok = CheckAndDeclareArrowParameter(this, expression, scope, &num_params,
dupe_loc);
return num_params;
}
FunctionLiteral* Parser::ParseFunctionLiteral(
const AstRawString* function_name, Scanner::Location function_name_location,
bool name_is_strict_reserved, FunctionKind kind, int function_token_pos,
FunctionLiteral::FunctionType function_type,
FunctionLiteral::ArityRestriction arity_restriction, 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();
}
int num_parameters = 0;
// Function declarations are function scoped in normal mode, so they are
// hoisted. In harmony block scoping mode they are block scoped, so they
// are not hoisted.
//
// One tricky case are function declarations in a local sloppy-mode eval:
// their declaration is hoisted, but they still see the local scope. E.g.,
//
// function() {
// var x = 0
// try { throw 1 } catch (x) { eval("function g() { return x }") }
// return g()
// }
//
// needs to return 1. To distinguish such cases, we need to detect
// (1) whether a function stems from a sloppy eval, and
// (2) whether it actually hoists across the eval.
// Unfortunately, we do not represent sloppy eval scopes, so we do not have
// either information available directly, especially not when lazily compiling
// a function like 'g'. We hence rely on the following invariants:
// - (1) is the case iff the innermost scope of the deserialized scope chain
// under which we compile is _not_ a declaration scope. This holds because
// in all normal cases, function declarations are fully hoisted to a
// declaration scope and compiled relative to that.
// - (2) is the case iff the current declaration scope is still the original
// one relative to the deserialized scope chain. Otherwise we must be
// compiling a function in an inner declaration scope in the eval, e.g. a
// nested function, and hoisting works normally relative to that.
Scope* declaration_scope = scope_->DeclarationScope();
Scope* original_declaration_scope = original_scope_->DeclarationScope();
Scope* scope =
function_type == FunctionLiteral::DECLARATION &&
(!allow_harmony_scoping() || strict_mode() == SLOPPY) &&
(original_scope_ == original_declaration_scope ||
declaration_scope != original_declaration_scope)
? NewScope(declaration_scope, FUNCTION_SCOPE)
: NewScope(scope_, FUNCTION_SCOPE);
ZoneList<Statement*>* body = NULL;
int materialized_literal_count = -1;
int expected_property_count = -1;
int handler_count = 0;
FunctionLiteral::ParameterFlag duplicate_parameters =
FunctionLiteral::kNoDuplicateParameters;
FunctionLiteral::IsParenthesizedFlag parenthesized = parenthesized_function_
? FunctionLiteral::kIsParenthesized
: FunctionLiteral::kNotParenthesized;
AstProperties ast_properties;
BailoutReason dont_optimize_reason = kNoReason;
// Parse function body.
{
AstNodeFactory<AstConstructionVisitor> function_factory(
ast_value_factory());
FunctionState function_state(&function_state_, &scope_, scope,
&function_factory);
scope_->SetScopeName(function_name);
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.
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_->DeclarationScope()->NewTemporary(
ast_value_factory()->dot_generator_object_string());
function_state.set_generator_object_variable(temp);
}
// FormalParameterList ::
// '(' (Identifier)*[','] ')'
Expect(Token::LPAREN, CHECK_OK);
scope->set_start_position(scanner()->location().beg_pos);
// We don't yet know if the function will be strict, so we cannot yet
// produce errors for parameter names or duplicates. However, we remember
// the locations of these errors if they occur and produce the errors later.
Scanner::Location eval_args_error_log = Scanner::Location::invalid();
Scanner::Location dupe_error_loc = Scanner::Location::invalid();
Scanner::Location reserved_loc = Scanner::Location::invalid();
bool done = arity_restriction == FunctionLiteral::GETTER_ARITY ||
(peek() == Token::RPAREN &&
arity_restriction != FunctionLiteral::SETTER_ARITY);
while (!done) {
bool is_strict_reserved = false;
const AstRawString* param_name =
ParseIdentifierOrStrictReservedWord(&is_strict_reserved, CHECK_OK);
// Store locations for possible future error reports.
if (!eval_args_error_log.IsValid() && IsEvalOrArguments(param_name)) {
eval_args_error_log = scanner()->location();
}
if (!reserved_loc.IsValid() && is_strict_reserved) {
reserved_loc = scanner()->location();
}
if (!dupe_error_loc.IsValid() && scope_->IsDeclared(param_name)) {
duplicate_parameters = FunctionLiteral::kHasDuplicateParameters;
dupe_error_loc = scanner()->location();
}
Variable* var = scope_->DeclareParameter(param_name, VAR);
if (scope->strict_mode() == SLOPPY) {
// TODO(sigurds) Mark every parameter as maybe assigned. This is a
// conservative approximation necessary to account for parameters
// that are assigned via the arguments array.
var->set_maybe_assigned();
}
num_parameters++;
if (num_parameters > Code::kMaxArguments) {
ReportMessage("too_many_parameters");
*ok = false;
return NULL;
}
if (arity_restriction == FunctionLiteral::SETTER_ARITY) break;
done = (peek() == Token::RPAREN);
if (!done) Expect(Token::COMMA, CHECK_OK);
}
Expect(Token::RPAREN, CHECK_OK);
Expect(Token::LBRACE, CHECK_OK);
// 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).
// 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 Proxis as is the case now.
Variable* fvar = NULL;
Token::Value fvar_init_op = Token::INIT_CONST_LEGACY;
if (function_type == FunctionLiteral::NAMED_EXPRESSION) {
if (allow_harmony_scoping() && strict_mode() == STRICT) {
fvar_init_op = Token::INIT_CONST;
}
VariableMode fvar_mode =
allow_harmony_scoping() && strict_mode() == STRICT
? CONST : CONST_LEGACY;
DCHECK(function_name != NULL);
fvar = new (zone())
Variable(scope_, function_name, fvar_mode, true /* is valid LHS */,
Variable::NORMAL, kCreatedInitialized, kNotAssigned,
Interface::NewConst());
VariableProxy* proxy = factory()->NewVariableProxy(fvar);
VariableDeclaration* fvar_declaration = factory()->NewVariableDeclaration(
proxy, fvar_mode, scope_, RelocInfo::kNoPosition);
scope_->DeclareFunctionVar(fvar_declaration);
}
// 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_->AllowsLazyCompilation() &&
!parenthesized_function_);
parenthesized_function_ = false; // The bit was set for this function only.
if (is_lazily_parsed) {
SkipLazyFunctionBody(function_name, &materialized_literal_count,
&expected_property_count, CHECK_OK);
} else {
body = ParseEagerFunctionBody(function_name, pos, fvar, fvar_init_op,
is_generator, CHECK_OK);
materialized_literal_count = function_state.materialized_literal_count();
expected_property_count = function_state.expected_property_count();
handler_count = function_state.handler_count();
}
// Validate strict mode.
// Concise methods use StrictFormalParameters.
if (strict_mode() == STRICT || IsConciseMethod(kind)) {
CheckStrictFunctionNameAndParameters(function_name,
name_is_strict_reserved,
function_name_location,
eval_args_error_log,
dupe_error_loc,
reserved_loc,
CHECK_OK);
}
if (strict_mode() == STRICT) {
CheckOctalLiteral(scope->start_position(),
scope->end_position(),
CHECK_OK);
}
ast_properties = *factory()->visitor()->ast_properties();
dont_optimize_reason = factory()->visitor()->dont_optimize_reason();
if (allow_harmony_scoping() && strict_mode() == STRICT) {
CheckConflictingVarDeclarations(scope, CHECK_OK);
}
}
FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
function_name, ast_value_factory(), scope, body,
materialized_literal_count, expected_property_count, handler_count,
num_parameters, duplicate_parameters, function_type,
FunctionLiteral::kIsFunction, parenthesized, kind, pos);
function_literal->set_function_token_position(function_token_pos);
function_literal->set_ast_properties(&ast_properties);
function_literal->set_dont_optimize_reason(dont_optimize_reason);
if (fni_ != NULL && should_infer_name) fni_->AddFunction(function_literal);
return function_literal;
}
void Parser::SkipLazyFunctionBody(const AstRawString* function_name,
int* materialized_literal_count,
int* expected_property_count,
bool* ok) {
// Temporary debugging code for tracking down a mystery crash which should
// never happen. The crash happens on the line where we log the function in
// the preparse data: log_->LogFunction(...). TODO(marja): remove this once
// done.
CHECK(materialized_literal_count);
CHECK(expected_property_count);
CHECK(debug_saved_compile_options_ == compile_options());
if (compile_options() == ScriptCompiler::kProduceParserCache) {
CHECK(log_);
}
int function_block_pos = position();
if (compile_options() == ScriptCompiler::kConsumeParserCache) {
// 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.
CHECK(entry.is_valid());
// End position greater than end of stream is safe, and hard to check.
CHECK(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();
scope_->SetStrictMode(entry.strict_mode());
} else {
// 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);
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.is_reference_error());
*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();
scope_->SetStrictMode(logger.strict_mode());
if (compile_options() == ScriptCompiler::kProduceParserCache) {
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_->strict_mode());
}
}
}
ZoneList<Statement*>* Parser::ParseEagerFunctionBody(
const AstRawString* function_name, int pos, Variable* fvar,
Token::Value fvar_init_op, bool is_generator, bool* ok) {
// Everything inside an eagerly parsed function will be parsed eagerly
// (see comment above).
ParsingModeScope parsing_mode(this, PARSE_EAGERLY);
ZoneList<Statement*>* body = new(zone()) ZoneList<Statement*>(8, zone());
if (fvar != NULL) {
VariableProxy* fproxy = scope_->NewUnresolved(
factory(), function_name, Interface::NewConst());
fproxy->BindTo(fvar);
body->Add(factory()->NewExpressionStatement(
factory()->NewAssignment(fvar_init_op,
fproxy,
factory()->NewThisFunction(pos),
RelocInfo::kNoPosition),
RelocInfo::kNoPosition), zone());
}
// For generators, allocate and yield an iterator on function entry.
if (is_generator) {
ZoneList<Expression*>* arguments =
new(zone()) ZoneList<Expression*>(0, zone());
CallRuntime* allocation = factory()->NewCallRuntime(
ast_value_factory()->empty_string(),
Runtime::FunctionForId(Runtime::kCreateJSGeneratorObject), arguments,
pos);
VariableProxy* init_proxy = factory()->NewVariableProxy(
function_state_->generator_object_variable());
Assignment* assignment = factory()->NewAssignment(
Token::INIT_VAR, init_proxy, allocation, RelocInfo::kNoPosition);
VariableProxy* get_proxy = factory()->NewVariableProxy(
function_state_->generator_object_variable());
Yield* yield = factory()->NewYield(
get_proxy, assignment, Yield::kInitial, RelocInfo::kNoPosition);
body->Add(factory()->NewExpressionStatement(
yield, RelocInfo::kNoPosition), zone());
}
ParseSourceElements(body, Token::RBRACE, false, false, NULL, CHECK_OK);
if (is_generator) {
VariableProxy* get_proxy = factory()->NewVariableProxy(
function_state_->generator_object_variable());
Expression* undefined =
factory()->NewUndefinedLiteral(RelocInfo::kNoPosition);
Yield* yield = factory()->NewYield(get_proxy, undefined, Yield::kFinal,
RelocInfo::kNoPosition);
body->Add(factory()->NewExpressionStatement(
yield, RelocInfo::kNoPosition), zone());
}
Expect(Token::RBRACE, CHECK_OK);
scope_->set_end_position(scanner()->location().end_pos);
return body;
}
PreParser::PreParseResult Parser::ParseLazyFunctionBodyWithPreParser(
SingletonLogger* logger) {
// 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();
}
DCHECK_EQ(Token::LBRACE, scanner()->current_token());
if (reusable_preparser_ == NULL) {
reusable_preparser_ = new PreParser(&scanner_, NULL, stack_limit_);
reusable_preparser_->set_allow_harmony_scoping(allow_harmony_scoping());
reusable_preparser_->set_allow_modules(allow_modules());
reusable_preparser_->set_allow_natives_syntax(allow_natives_syntax());
reusable_preparser_->set_allow_lazy(true);
reusable_preparser_->set_allow_arrow_functions(allow_arrow_functions());
reusable_preparser_->set_allow_harmony_numeric_literals(
allow_harmony_numeric_literals());
reusable_preparser_->set_allow_classes(allow_classes());
reusable_preparser_->set_allow_harmony_object_literals(
allow_harmony_object_literals());
}
PreParser::PreParseResult result =
reusable_preparser_->PreParseLazyFunction(strict_mode(),
is_generator(),
logger);
if (pre_parse_timer_ != NULL) {
pre_parse_timer_->Stop();
}
return result;
}
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(kAllowEvalOrArguments, CHECK_OK);
ZoneList<Expression*>* args = ParseArguments(CHECK_OK);
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());
// Check for built-in IS_VAR macro.
if (function != NULL &&
function->intrinsic_type == Runtime::RUNTIME &&
function->function_id == Runtime::kIS_VAR) {
// %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("not_isvar");
*ok = false;
return NULL;
}
}
// Check that the expected number of arguments are being passed.
if (function != NULL &&
function->nargs != -1 &&
function->nargs != args->length()) {
ReportMessage("illegal_access");
*ok = false;
return NULL;
}
// Check that the function is defined if it's an inline runtime call.
if (function == NULL && name->FirstCharacter() == '_') {
ParserTraits::ReportMessage("not_defined", name);
*ok = false;
return NULL;
}
// We have a valid intrinsics call or a call to a builtin.
return factory()->NewCallRuntime(name, function, 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 harmony mode we treat conflicting variable bindinds as early
// errors. See ES5 16 for a definition of 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, "var_redeclaration", name);
*ok = false;
}
}
// ----------------------------------------------------------------------------
// Parser support
bool Parser::TargetStackContainsLabel(const AstRawString* label) {
for (Target* t = target_stack_; t != NULL; t = t->previous()) {
BreakableStatement* stat = t->node()->AsBreakableStatement();
if (stat != NULL && ContainsLabel(stat->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->node()->AsBreakableStatement();
if (stat == NULL) continue;
if ((anonymous && stat->is_target_for_anonymous()) ||
(!anonymous && ContainsLabel(stat->labels(), label))) {
RegisterTargetUse(stat->break_target(), t->previous());
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->node()->AsIterationStatement();
if (stat == NULL) continue;
DCHECK(stat->is_target_for_anonymous());
if (anonymous || ContainsLabel(stat->labels(), label)) {
RegisterTargetUse(stat->continue_target(), t->previous());
return stat;
}
}
return NULL;
}
void Parser::RegisterTargetUse(Label* target, Target* stop) {
// Register that a break target found at the given stop in the
// target stack has been used from the top of the target stack. Add
// the break target to any TargetCollectors passed on the stack.
for (Target* t = target_stack_; t != stop; t = t->previous()) {
TargetCollector* collector = t->node()->AsTargetCollector();
if (collector != NULL) collector->AddTarget(target, zone());
}
}
void Parser::HandleSourceURLComments() {
if (scanner_.source_url()->length() > 0) {
Handle<String> source_url = scanner_.source_url()->Internalize(isolate());
info_->script()->set_source_url(*source_url);
}
if (scanner_.source_mapping_url()->length() > 0) {
Handle<String> source_mapping_url =
scanner_.source_mapping_url()->Internalize(isolate());
info_->script()->set_source_mapping_url(*source_mapping_url);
}
}
void Parser::ThrowPendingError() {
DCHECK(ast_value_factory()->IsInternalized());
if (has_pending_error_) {
MessageLocation location(script(), pending_error_location_.beg_pos,
pending_error_location_.end_pos);
Factory* factory = isolate()->factory();
bool has_arg =
pending_error_arg_ != NULL || pending_error_char_arg_ != NULL;
Handle<FixedArray> elements = factory->NewFixedArray(has_arg ? 1 : 0);
if (pending_error_arg_ != NULL) {
Handle<String> arg_string = pending_error_arg_->string();
elements->set(0, *arg_string);
} else if (pending_error_char_arg_ != NULL) {
Handle<String> arg_string =
factory->NewStringFromUtf8(CStrVector(pending_error_char_arg_))
.ToHandleChecked();
elements->set(0, *arg_string);
}
isolate()->debug()->OnCompileError(script());
Handle<JSArray> array = factory->NewJSArrayWithElements(elements);
Handle<Object> error;
MaybeHandle<Object> maybe_error =
pending_error_is_reference_error_
? factory->NewReferenceError(pending_error_message_, array)
: factory->NewSyntaxError(pending_error_message_, array);
if (maybe_error.ToHandle(&error)) isolate()->Throw(*error, &location);
}
}
void Parser::Internalize() {
// Internalize strings.
ast_value_factory()->Internalize(isolate());
// Error processing.
if (info()->function() == NULL) {
if (stack_overflow()) {
isolate()->StackOverflow();
} else {
ThrowPendingError();
}
}
// 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));
}
}
isolate()->counters()->total_preparse_skipped()->Increment(
total_preparse_skipped_);
}
// ----------------------------------------------------------------------------
// Regular expressions
RegExpParser::RegExpParser(FlatStringReader* in,
Handle<String>* error,
bool multiline,
Zone* zone)
: isolate_(zone->isolate()),
zone_(zone),
error_(error),
captures_(NULL),
in_(in),
current_(kEndMarker),
next_pos_(0),
capture_count_(0),
has_more_(true),
multiline_(multiline),
simple_(false),
contains_anchor_(false),
is_scanned_for_captures_(false),
failed_(false) {
Advance();
}
uc32 RegExpParser::Next() {
if (has_next()) {
return in()->Get(next_pos_);
} else {
return kEndMarker;
}
}
void RegExpParser::Advance() {
if (next_pos_ < in()->length()) {
StackLimitCheck check(isolate());
if (check.HasOverflowed()) {
ReportError(CStrVector(Isolate::kStackOverflowMessage));
} else if (zone()->excess_allocation()) {
ReportError(CStrVector("Regular expression too large"));
} else {
current_ = in()->Get(next_pos_);
next_pos_++;
}
} else {
current_ = kEndMarker;
has_more_ = false;
}
}
void RegExpParser::Reset(int pos) {
next_pos_ = pos;
has_more_ = (pos < in()->length());
Advance();
}
void RegExpParser::Advance(int dist) {
next_pos_ += dist - 1;
Advance();
}
bool RegExpParser::simple() {
return simple_;
}
RegExpTree* RegExpParser::ReportError(Vector<const char> message) {
failed_ = true;
*error_ = isolate()->factory()->NewStringFromAscii(message).ToHandleChecked();
// Zip to the end to make sure the no more input is read.
current_ = kEndMarker;
next_pos_ = in()->length();
return NULL;
}
// Pattern ::
// Disjunction
RegExpTree* RegExpParser::ParsePattern() {
RegExpTree* result = ParseDisjunction(CHECK_FAILED);
DCHECK(!has_more());
// If the result of parsing is a literal string atom, and it has the
// same length as the input, then the atom is identical to the input.
if (result->IsAtom() && result->AsAtom()->length() == in()->length()) {
simple_ = true;
}
return result;
}
// Disjunction ::
// Alternative
// Alternative | Disjunction
// Alternative ::
// [empty]
// Term Alternative
// Term ::
// Assertion
// Atom
// Atom Quantifier
RegExpTree* RegExpParser::ParseDisjunction() {
// Used to store current state while parsing subexpressions.
RegExpParserState initial_state(NULL, INITIAL, 0, zone());
RegExpParserState* stored_state = &initial_state;
// Cache the builder in a local variable for quick access.
RegExpBuilder* builder = initial_state.builder();
while (true) {
switch (current()) {
case kEndMarker:
if (stored_state->IsSubexpression()) {
// Inside a parenthesized group when hitting end of input.
ReportError(CStrVector("Unterminated group") CHECK_FAILED);
}
DCHECK_EQ(INITIAL, stored_state->group_type());
// Parsing completed successfully.
return builder->ToRegExp();
case ')': {
if (!stored_state->IsSubexpression()) {
ReportError(CStrVector("Unmatched ')'") CHECK_FAILED);
}
DCHECK_NE(INITIAL, stored_state->group_type());
Advance();
// End disjunction parsing and convert builder content to new single
// regexp atom.
RegExpTree* body = builder->ToRegExp();
int end_capture_index = captures_started();
int capture_index = stored_state->capture_index();
SubexpressionType group_type = stored_state->group_type();
// Restore previous state.
stored_state = stored_state->previous_state();
builder = stored_state->builder();
// Build result of subexpression.
if (group_type == CAPTURE) {
RegExpCapture* capture = new(zone()) RegExpCapture(body, capture_index);
captures_->at(capture_index - 1) = capture;
body = capture;
} else if (group_type != GROUPING) {
DCHECK(group_type == POSITIVE_LOOKAHEAD ||
group_type == NEGATIVE_LOOKAHEAD);
bool is_positive = (group_type == POSITIVE_LOOKAHEAD);
body = new(zone()) RegExpLookahead(body,
is_positive,
end_capture_index - capture_index,
capture_index);
}
builder->AddAtom(body);
// For compatability with JSC and ES3, we allow quantifiers after
// lookaheads, and break in all cases.
break;
}
case '|': {
Advance();
builder->NewAlternative();
continue;
}
case '*':
case '+':
case '?':
return ReportError(CStrVector("Nothing to repeat"));
case '^': {
Advance();
if (multiline_) {
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::START_OF_LINE));
} else {
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::START_OF_INPUT));
set_contains_anchor();
}
continue;
}
case '$': {
Advance();
RegExpAssertion::AssertionType assertion_type =
multiline_ ? RegExpAssertion::END_OF_LINE :
RegExpAssertion::END_OF_INPUT;
builder->AddAssertion(new(zone()) RegExpAssertion(assertion_type));
continue;
}
case '.': {
Advance();
// everything except \x0a, \x0d, \u2028 and \u2029
ZoneList<CharacterRange>* ranges =
new(zone()) ZoneList<CharacterRange>(2, zone());
CharacterRange::AddClassEscape('.', ranges, zone());
RegExpTree* atom = new(zone()) RegExpCharacterClass(ranges, false);
builder->AddAtom(atom);
break;
}
case '(': {
SubexpressionType subexpr_type = CAPTURE;
Advance();
if (current() == '?') {
switch (Next()) {
case ':':
subexpr_type = GROUPING;
break;
case '=':
subexpr_type = POSITIVE_LOOKAHEAD;
break;
case '!':
subexpr_type = NEGATIVE_LOOKAHEAD;
break;
default:
ReportError(CStrVector("Invalid group") CHECK_FAILED);
break;
}
Advance(2);
} else {
if (captures_ == NULL) {
captures_ = new(zone()) ZoneList<RegExpCapture*>(2, zone());
}
if (captures_started() >= kMaxCaptures) {
ReportError(CStrVector("Too many captures") CHECK_FAILED);
}
captures_->Add(NULL, zone());
}
// Store current state and begin new disjunction parsing.
stored_state = new(zone()) RegExpParserState(stored_state, subexpr_type,
captures_started(), zone());
builder = stored_state->builder();
continue;
}
case '[': {
RegExpTree* atom = ParseCharacterClass(CHECK_FAILED);
builder->AddAtom(atom);
break;
}
// Atom ::
// \ AtomEscape
case '\\':
switch (Next()) {
case kEndMarker:
return ReportError(CStrVector("\\ at end of pattern"));
case 'b':
Advance(2);
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::BOUNDARY));
continue;
case 'B':
Advance(2);
builder->AddAssertion(
new(zone()) RegExpAssertion(RegExpAssertion::NON_BOUNDARY));
continue;
// AtomEscape ::
// CharacterClassEscape
//
// CharacterClassEscape :: one of
// d D s S w W
case 'd': case 'D': case 's': case 'S': case 'w': case 'W': {
uc32 c = Next();
Advance(2);
ZoneList<CharacterRange>* ranges =
new(zone()) ZoneList<CharacterRange>(2, zone());
CharacterRange::AddClassEscape(c, ranges, zone());
RegExpTree* atom = new(zone()) RegExpCharacterClass(ranges, false);
builder->AddAtom(atom);
break;
}
case '1': case '2': case '3': case '4': case '5': case '6':
case '7': case '8': case '9': {
int index = 0;
if (ParseBackReferenceIndex(&index)) {
RegExpCapture* capture = NULL;
if (captures_ != NULL && index <= captures_->length()) {
capture = captures_->at(index - 1);
}
if (capture == NULL) {
builder->AddEmpty();
break;
}
RegExpTree* atom = new(zone()) RegExpBackReference(capture);
builder->AddAtom(atom);
break;
}
uc32 first_digit = Next();
if (first_digit == '8' || first_digit == '9') {
// Treat as identity escape
builder->AddCharacter(first_digit);
Advance(2);
break;
}
}
// FALLTHROUGH
case '0': {
Advance();
uc32 octal = ParseOctalLiteral();
builder->AddCharacter(octal);
break;
}
// ControlEscape :: one of
// f n r t v
case 'f':
Advance(2);
builder->AddCharacter('\f');
break;
case 'n':
Advance(2);
builder->AddCharacter('\n');
break;
case 'r':
Advance(2);
builder->AddCharacter('\r');
break;
case 't':
Advance(2);
builder->AddCharacter('\t');
break;
case 'v':
Advance(2);
builder->AddCharacter('\v');
break;
case 'c': {
Advance();
uc32 controlLetter = Next();
// Special case if it is an ASCII letter.
// Convert lower case letters to uppercase.
uc32 letter = controlLetter & ~('a' ^ 'A');
if (letter < 'A' || 'Z' < letter) {
// controlLetter is not in range 'A'-'Z' or 'a'-'z'.
// This is outside the specification. We match JSC in
// reading the backslash as a literal character instead
// of as starting an escape.
builder->AddCharacter('\\');
} else {
Advance(2);
builder->AddCharacter(controlLetter & 0x1f);
}
break;
}
case 'x': {
Advance(2);
uc32 value;
if (ParseHexEscape(2, &value)) {
builder->AddCharacter(value);
} else {
builder->AddCharacter('x');
}
break;
}
case 'u': {
Advance(2);
uc32 value;
if (ParseHexEscape(4, &value)) {
builder->AddCharacter(value);
} else {
builder->AddCharacter('u');
}
break;
}
default:
// Identity escape.
builder->AddCharacter(Next());
Advance(2);
break;
}
break;
case '{': {
int dummy;
if (ParseIntervalQuantifier(&dummy, &dummy)) {
ReportError(CStrVector("Nothing to repeat") CHECK_FAILED);
}
// fallthrough
}
default:
builder->AddCharacter(current());
Advance();
break;
} // end switch(current())
int min;
int max;
switch (current()) {
// QuantifierPrefix ::
// *
// +
// ?
// {
case '*':
min = 0;
max = RegExpTree::kInfinity;
Advance();
break;
case '+':
min = 1;
max = RegExpTree::kInfinity;
Advance();
break;
case '?':
min = 0;
max = 1;
Advance();
break;
case '{':
if (ParseIntervalQuantifier(&min, &max)) {
if (max < min) {
ReportError(CStrVector("numbers out of order in {} quantifier.")
CHECK_FAILED);
}
break;
} else {
continue;
}
default:
continue;
}
RegExpQuantifier::QuantifierType quantifier_type = RegExpQuantifier::GREEDY;
if (current() == '?') {
quantifier_type = RegExpQuantifier::NON_GREEDY;
Advance();
} else if (FLAG_regexp_possessive_quantifier && current() == '+') {
// FLAG_regexp_possessive_quantifier is a debug-only flag.
quantifier_type = RegExpQuantifier::POSSESSIVE;
Advance();
}
builder->AddQuantifierToAtom(min, max, quantifier_type);
}
}
#ifdef DEBUG
// Currently only used in an DCHECK.
static bool IsSpecialClassEscape(uc32 c) {
switch (c) {
case 'd': case 'D':
case 's': case 'S':
case 'w': case 'W':
return true;
default:
return false;
}
}
#endif
// In order to know whether an escape is a backreference or not we have to scan
// the entire regexp and find the number of capturing parentheses. However we
// don't want to scan the regexp twice unless it is necessary. This mini-parser
// is called when needed. It can see the difference between capturing and
// noncapturing parentheses and can skip character classes and backslash-escaped
// characters.
void RegExpParser::ScanForCaptures() {
// Start with captures started previous to current position
int capture_count = captures_started();
// Add count of captures after this position.
int n;
while ((n = current()) != kEndMarker) {
Advance();
switch (n) {
case '\\':
Advance();
break;
case '[': {
int c;
while ((c = current()) != kEndMarker) {
Advance();
if (c == '\\') {
Advance();
} else {
if (c == ']') break;
}
}
break;
}
case '(':
if (current() != '?') capture_count++;
break;
}
}
capture_count_ = capture_count;
is_scanned_for_captures_ = true;
}
bool RegExpParser::ParseBackReferenceIndex(int* index_out) {
DCHECK_EQ('\\', current());
DCHECK('1' <= Next() && Next() <= '9');
// Try to parse a decimal literal that is no greater than the total number
// of left capturing parentheses in the input.
int start = position();
int value = Next() - '0';
Advance(2);
while (true) {
uc32 c = current();
if (IsDecimalDigit(c)) {
value = 10 * value + (c - '0');
if (value > kMaxCaptures) {
Reset(start);
return false;
}
Advance();
} else {
break;
}
}
if (value > captures_started()) {
if (!is_scanned_for_captures_) {
int saved_position = position();
ScanForCaptures();
Reset(saved_position);
}
if (value > capture_count_) {
Reset(start);
return false;
}
}
*index_out = value;
return true;
}
// QuantifierPrefix ::
// { DecimalDigits }
// { DecimalDigits , }
// { DecimalDigits , DecimalDigits }
//
// Returns true if parsing succeeds, and set the min_out and max_out
// values. Values are truncated to RegExpTree::kInfinity if they overflow.
bool RegExpParser::ParseIntervalQuantifier(int* min_out, int* max_out) {
DCHECK_EQ(current(), '{');
int start = position();
Advance();
int min = 0;
if (!IsDecimalDigit(current())) {
Reset(start);
return false;
}
while (IsDecimalDigit(current())) {
int next = current() - '0';
if (min > (RegExpTree::kInfinity - next) / 10) {
// Overflow. Skip past remaining decimal digits and return -1.
do {
Advance();
} while (IsDecimalDigit(current()));
min = RegExpTree::kInfinity;
break;
}
min = 10 * min + next;
Advance();
}
int max = 0;
if (current() == '}') {
max = min;
Advance();
} else if (current() == ',') {
Advance();
if (current() == '}') {
max = RegExpTree::kInfinity;
Advance();
} else {
while (IsDecimalDigit(current())) {
int next = current() - '0';
if (max > (RegExpTree::kInfinity - next) / 10) {
do {
Advance();
} while (IsDecimalDigit(current()));
max = RegExpTree::kInfinity;
break;
}
max = 10 * max + next;
Advance();
}
if (current() != '}') {
Reset(start);
return false;
}
Advance();
}
} else {
Reset(start);
return false;
}
*min_out = min;
*max_out = max;
return true;
}
uc32 RegExpParser::ParseOctalLiteral() {
DCHECK(('0' <= current() && current() <= '7') || current() == kEndMarker);
// For compatibility with some other browsers (not all), we parse
// up to three octal digits with a value below 256.
uc32 value = current() - '0';
Advance();
if ('0' <= current() && current() <= '7') {
value = value * 8 + current() - '0';
Advance();
if (value < 32 && '0' <= current() && current() <= '7') {
value = value * 8 + current() - '0';
Advance();
}
}
return value;
}
bool RegExpParser::ParseHexEscape(int length, uc32 *value) {
int start = position();
uc32 val = 0;
bool done = false;
for (int i = 0; !done; i++) {
uc32 c = current();
int d = HexValue(c);
if (d < 0) {
Reset(start);
return false;
}
val = val * 16 + d;
Advance();
if (i == length - 1) {
done = true;
}
}
*value = val;
return true;
}
uc32 RegExpParser::ParseClassCharacterEscape() {
DCHECK(current() == '\\');
DCHECK(has_next() && !IsSpecialClassEscape(Next()));
Advance();
switch (current()) {
case 'b':
Advance();
return '\b';
// ControlEscape :: one of
// f n r t v
case 'f':
Advance();
return '\f';
case 'n':
Advance();
return '\n';
case 'r':
Advance();
return '\r';
case 't':
Advance();
return '\t';
case 'v':
Advance();
return '\v';
case 'c': {
uc32 controlLetter = Next();
uc32 letter = controlLetter & ~('A' ^ 'a');
// For compatibility with JSC, inside a character class
// we also accept digits and underscore as control characters.
if ((controlLetter >= '0' && controlLetter <= '9') ||
controlLetter == '_' ||
(letter >= 'A' && letter <= 'Z')) {
Advance(2);
// Control letters mapped to ASCII control characters in the range
// 0x00-0x1f.
return controlLetter & 0x1f;
}
// We match JSC in reading the backslash as a literal
// character instead of as starting an escape.
return '\\';
}
case '0': case '1': case '2': case '3': case '4': case '5':
case '6': case '7':
// For compatibility, we interpret a decimal escape that isn't
// a back reference (and therefore either \0 or not valid according
// to the specification) as a 1..3 digit octal character code.
return ParseOctalLiteral();
case 'x': {
Advance();
uc32 value;
if (ParseHexEscape(2, &value)) {
return value;
}
// If \x is not followed by a two-digit hexadecimal, treat it
// as an identity escape.
return 'x';
}
case 'u': {
Advance();
uc32 value;
if (ParseHexEscape(4, &value)) {
return value;
}
// If \u is not followed by a four-digit hexadecimal, treat it
// as an identity escape.
return 'u';
}
default: {
// Extended identity escape. We accept any character that hasn't
// been matched by a more specific case, not just the subset required
// by the ECMAScript specification.
uc32 result = current();
Advance();
return result;
}
}
return 0;
}
CharacterRange RegExpParser::ParseClassAtom(uc16* char_class) {
DCHECK_EQ(0, *char_class);
uc32 first = current();
if (first == '\\') {
switch (Next()) {
case 'w': case 'W': case 'd': case 'D': case 's': case 'S': {
*char_class = Next();
Advance(2);
return CharacterRange::Singleton(0); // Return dummy value.
}
case kEndMarker:
return ReportError(CStrVector("\\ at end of pattern"));
default:
uc32 c = ParseClassCharacterEscape(CHECK_FAILED);
return CharacterRange::Singleton(c);
}
} else {
Advance();
return CharacterRange::Singleton(first);
}
}
static const uc16 kNoCharClass = 0;
// Adds range or pre-defined character class to character ranges.
// If char_class is not kInvalidClass, it's interpreted as a class
// escape (i.e., 's' means whitespace, from '\s').
static inline void AddRangeOrEscape(ZoneList<CharacterRange>* ranges,
uc16 char_class,
CharacterRange range,
Zone* zone) {
if (char_class != kNoCharClass) {
CharacterRange::AddClassEscape(char_class, ranges, zone);
} else {
ranges->Add(range, zone);
}
}
RegExpTree* RegExpParser::ParseCharacterClass() {
static const char* kUnterminated = "Unterminated character class";
static const char* kRangeOutOfOrder = "Range out of order in character class";
DCHECK_EQ(current(), '[');
Advance();
bool is_negated = false;
if (current() == '^') {
is_negated = true;
Advance();
}
ZoneList<CharacterRange>* ranges =
new(zone()) ZoneList<CharacterRange>(2, zone());
while (has_more() && current() != ']') {
uc16 char_class = kNoCharClass;
CharacterRange first = ParseClassAtom(&char_class CHECK_FAILED);
if (current() == '-') {
Advance();
if (current() == kEndMarker) {
// If we reach the end we break out of the loop and let the
// following code report an error.
break;
} else if (current() == ']') {
AddRangeOrEscape(ranges, char_class, first, zone());
ranges->Add(CharacterRange::Singleton('-'), zone());
break;
}
uc16 char_class_2 = kNoCharClass;
CharacterRange next = ParseClassAtom(&char_class_2 CHECK_FAILED);
if (char_class != kNoCharClass || char_class_2 != kNoCharClass) {
// Either end is an escaped character class. Treat the '-' verbatim.
AddRangeOrEscape(ranges, char_class, first, zone());
ranges->Add(CharacterRange::Singleton('-'), zone());
AddRangeOrEscape(ranges, char_class_2, next, zone());
continue;
}
if (first.from() > next.to()) {
return ReportError(CStrVector(kRangeOutOfOrder) CHECK_FAILED);
}
ranges->Add(CharacterRange::Range(first.from(), next.to()), zone());
} else {
AddRangeOrEscape(ranges, char_class, first, zone());
}
}
if (!has_more()) {
return ReportError(CStrVector(kUnterminated) CHECK_FAILED);
}
Advance();
if (ranges->length() == 0) {
ranges->Add(CharacterRange::Everything(), zone());
is_negated = !is_negated;
}
return new(zone()) RegExpCharacterClass(ranges, is_negated);
}
// ----------------------------------------------------------------------------
// The Parser interface.
bool RegExpParser::ParseRegExp(FlatStringReader* input,
bool multiline,
RegExpCompileData* result,
Zone* zone) {
DCHECK(result != NULL);
RegExpParser parser(input, &result->error, multiline, zone);
RegExpTree* tree = parser.ParsePattern();
if (parser.failed()) {
DCHECK(tree == NULL);
DCHECK(!result->error.is_null());
} else {
DCHECK(tree != NULL);
DCHECK(result->error.is_null());
result->tree = tree;
int capture_count = parser.captures_started();
result->simple = tree->IsAtom() && parser.simple() && capture_count == 0;
result->contains_anchor = parser.contains_anchor();
result->capture_count = capture_count;
}
return !parser.failed();
}
bool Parser::Parse() {
DCHECK(info()->function() == NULL);
FunctionLiteral* result = NULL;
pre_parse_timer_ = isolate()->counters()->pre_parse();
if (FLAG_trace_parse || allow_natives_syntax() || 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();
} else {
result = ParseProgram();
}
} else {
SetCachedData();
result = ParseProgram();
}
info()->SetFunction(result);
Internalize();
DCHECK(ast_value_factory()->IsInternalized());
return (result != NULL);
}
void Parser::ParseOnBackground() {
DCHECK(info()->function() == NULL);
FunctionLiteral* result = NULL;
fni_ = new (zone()) FuncNameInferrer(ast_value_factory(), zone());
CompleteParserRecorder recorder;
debug_saved_compile_options_ = compile_options();
if (compile_options() == ScriptCompiler::kProduceParserCache) {
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.
Scope* top_scope = NULL;
Scope* eval_scope = NULL;
result = DoParseProgram(info(), &top_scope, &eval_scope);
top_scope->set_end_position(scanner()->location().end_pos);
if (eval_scope != NULL) {
eval_scope->set_end_position(scanner()->location().end_pos);
}
info()->SetFunction(result);
// We cannot internalize on a background thread; a foreground task will take
// care of calling Parser::Internalize just before compilation.
if (compile_options() == ScriptCompiler::kProduceParserCache) {
if (result != NULL) *info_->cached_data() = recorder.GetScriptData();
log_ = NULL;
}
}
} } // namespace v8::internal