blob: fffc3311027f44bc706b0ab23dd4df097a74e5a4 [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/parsing/parser.h"
#include <algorithm>
#include <memory>
#include "src/ast/ast-function-literal-id-reindexer.h"
#include "src/ast/ast-traversal-visitor.h"
#include "src/ast/ast.h"
#include "src/ast/source-range-ast-visitor.h"
#include "src/bailout-reason.h"
#include "src/base/overflowing-math.h"
#include "src/base/platform/platform.h"
#include "src/char-predicates-inl.h"
#include "src/compiler-dispatcher/compiler-dispatcher.h"
#include "src/conversions-inl.h"
#include "src/log.h"
#include "src/message-template.h"
#include "src/objects/scope-info.h"
#include "src/parsing/expression-scope-reparenter.h"
#include "src/parsing/parse-info.h"
#include "src/parsing/rewriter.h"
#include "src/runtime/runtime.h"
#include "src/string-stream.h"
#include "src/tracing/trace-event.h"
namespace v8 {
namespace internal {
FunctionLiteral* Parser::DefaultConstructor(const AstRawString* name,
bool call_super, int pos,
int end_pos) {
int expected_property_count = -1;
const int parameter_count = 0;
FunctionKind kind = call_super ? FunctionKind::kDefaultDerivedConstructor
: FunctionKind::kDefaultBaseConstructor;
DeclarationScope* function_scope = NewFunctionScope(kind);
SetLanguageMode(function_scope, LanguageMode::kStrict);
// Set start and end position to the same value
function_scope->set_start_position(pos);
function_scope->set_end_position(pos);
ScopedPtrList<Statement> body(pointer_buffer());
{
FunctionState function_state(&function_state_, &scope_, function_scope);
if (call_super) {
// Create a SuperCallReference and handle in BytecodeGenerator.
auto constructor_args_name = ast_value_factory()->empty_string();
bool is_rest = true;
bool is_optional = false;
Variable* constructor_args = function_scope->DeclareParameter(
constructor_args_name, VariableMode::kTemporary, is_optional, is_rest,
ast_value_factory(), pos);
Expression* call;
{
ScopedPtrList<Expression> args(pointer_buffer());
Spread* spread_args = factory()->NewSpread(
factory()->NewVariableProxy(constructor_args), pos, pos);
args.Add(spread_args);
Expression* super_call_ref = NewSuperCallReference(pos);
call = factory()->NewCall(super_call_ref, args, pos);
}
body.Add(factory()->NewReturnStatement(call, pos));
}
expected_property_count = function_state.expected_property_count();
}
FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
name, function_scope, body, expected_property_count, parameter_count,
parameter_count, FunctionLiteral::kNoDuplicateParameters,
FunctionLiteral::kAnonymousExpression, default_eager_compile_hint(), pos,
true, GetNextFunctionLiteralId());
return function_literal;
}
void Parser::ReportUnexpectedTokenAt(Scanner::Location location,
Token::Value token,
MessageTemplate message) {
const char* arg = nullptr;
switch (token) {
case Token::EOS:
message = MessageTemplate::kUnexpectedEOS;
break;
case Token::SMI:
case Token::NUMBER:
case Token::BIGINT:
message = MessageTemplate::kUnexpectedTokenNumber;
break;
case Token::STRING:
message = MessageTemplate::kUnexpectedTokenString;
break;
case Token::PRIVATE_NAME:
case Token::IDENTIFIER:
message = MessageTemplate::kUnexpectedTokenIdentifier;
break;
case Token::AWAIT:
case Token::ENUM:
message = MessageTemplate::kUnexpectedReserved;
break;
case Token::LET:
case Token::STATIC:
case Token::YIELD:
case Token::FUTURE_STRICT_RESERVED_WORD:
message = is_strict(language_mode())
? MessageTemplate::kUnexpectedStrictReserved
: MessageTemplate::kUnexpectedTokenIdentifier;
break;
case Token::TEMPLATE_SPAN:
case Token::TEMPLATE_TAIL:
message = MessageTemplate::kUnexpectedTemplateString;
break;
case Token::ESCAPED_STRICT_RESERVED_WORD:
case Token::ESCAPED_KEYWORD:
message = MessageTemplate::kInvalidEscapedReservedWord;
break;
case Token::ILLEGAL:
if (scanner()->has_error()) {
message = scanner()->error();
location = scanner()->error_location();
} else {
message = MessageTemplate::kInvalidOrUnexpectedToken;
}
break;
case Token::REGEXP_LITERAL:
message = MessageTemplate::kUnexpectedTokenRegExp;
break;
default:
const char* name = Token::String(token);
DCHECK_NOT_NULL(name);
arg = name;
break;
}
ReportMessageAt(location, message, arg);
}
// ----------------------------------------------------------------------------
// Implementation of Parser
bool Parser::ShortcutNumericLiteralBinaryExpression(Expression** x,
Expression* y,
Token::Value op, int pos) {
if ((*x)->IsNumberLiteral() && y->IsNumberLiteral()) {
double x_val = (*x)->AsLiteral()->AsNumber();
double y_val = y->AsLiteral()->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(base::Divide(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 =
base::ShlWithWraparound(DoubleToInt32(x_val), DoubleToInt32(y_val));
*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;
}
case Token::EXP: {
*x = factory()->NewNumberLiteral(Pow(x_val, y_val), pos);
return true;
}
default:
break;
}
}
return false;
}
bool Parser::CollapseNaryExpression(Expression** x, Expression* y,
Token::Value op, int pos,
const SourceRange& range) {
// Filter out unsupported ops.
if (!Token::IsBinaryOp(op) || op == Token::EXP) return false;
// Convert *x into an nary operation with the given op, returning false if
// this is not possible.
NaryOperation* nary = nullptr;
if ((*x)->IsBinaryOperation()) {
BinaryOperation* binop = (*x)->AsBinaryOperation();
if (binop->op() != op) return false;
nary = factory()->NewNaryOperation(op, binop->left(), 2);
nary->AddSubsequent(binop->right(), binop->position());
ConvertBinaryToNaryOperationSourceRange(binop, nary);
*x = nary;
} else if ((*x)->IsNaryOperation()) {
nary = (*x)->AsNaryOperation();
if (nary->op() != op) return false;
} else {
return false;
}
// Append our current expression to the nary operation.
// TODO(leszeks): Do some literal collapsing here if we're appending Smi or
// String literals.
nary->AddSubsequent(y, pos);
nary->clear_parenthesized();
AppendNaryOperationSourceRange(nary, range);
return true;
}
Expression* Parser::BuildUnaryExpression(Expression* expression,
Token::Value op, int pos) {
DCHECK_NOT_NULL(expression);
const Literal* literal = expression->AsLiteral();
if (literal != nullptr) {
if (op == Token::NOT) {
// Convert the literal to a boolean condition and negate it.
return factory()->NewBooleanLiteral(literal->ToBooleanIsFalse(), pos);
} else if (literal->IsNumberLiteral()) {
// 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;
}
}
}
return factory()->NewUnaryOperation(op, expression, pos);
}
Expression* Parser::NewThrowError(Runtime::FunctionId id,
MessageTemplate message,
const AstRawString* arg, int pos) {
ScopedPtrList<Expression> args(pointer_buffer());
args.Add(factory()->NewSmiLiteral(static_cast<int>(message), pos));
args.Add(factory()->NewStringLiteral(arg, pos));
CallRuntime* call_constructor = factory()->NewCallRuntime(id, args, pos);
return factory()->NewThrow(call_constructor, pos);
}
Expression* Parser::NewSuperPropertyReference(int pos) {
// this_function[home_object_symbol]
VariableProxy* this_function_proxy =
NewUnresolved(ast_value_factory()->this_function_string(), pos);
Expression* home_object_symbol_literal = factory()->NewSymbolLiteral(
AstSymbol::kHomeObjectSymbol, kNoSourcePosition);
Expression* home_object = factory()->NewProperty(
this_function_proxy, home_object_symbol_literal, pos);
return factory()->NewSuperPropertyReference(
ThisExpression(pos)->AsVariableProxy(), home_object, pos);
}
Expression* Parser::NewSuperCallReference(int pos) {
VariableProxy* new_target_proxy =
NewUnresolved(ast_value_factory()->new_target_string(), pos);
VariableProxy* this_function_proxy =
NewUnresolved(ast_value_factory()->this_function_string(), pos);
return factory()->NewSuperCallReference(
ThisExpression(pos)->AsVariableProxy(), new_target_proxy,
this_function_proxy, pos);
}
Expression* Parser::NewTargetExpression(int pos) {
auto proxy = NewUnresolved(ast_value_factory()->new_target_string(), pos);
proxy->set_is_new_target();
return proxy;
}
Expression* Parser::ImportMetaExpression(int pos) {
ScopedPtrList<Expression> args(pointer_buffer());
return factory()->NewCallRuntime(Runtime::kInlineGetImportMetaObject, args,
pos);
}
Expression* Parser::ExpressionFromLiteral(Token::Value token, int pos) {
switch (token) {
case Token::NULL_LITERAL:
return factory()->NewNullLiteral(pos);
case Token::TRUE_LITERAL:
return factory()->NewBooleanLiteral(true, pos);
case Token::FALSE_LITERAL:
return factory()->NewBooleanLiteral(false, pos);
case Token::SMI: {
uint32_t value = scanner()->smi_value();
return factory()->NewSmiLiteral(value, pos);
}
case Token::NUMBER: {
double value = scanner()->DoubleValue();
return factory()->NewNumberLiteral(value, pos);
}
case Token::BIGINT:
return factory()->NewBigIntLiteral(
AstBigInt(scanner()->CurrentLiteralAsCString(zone())), pos);
case Token::STRING: {
return factory()->NewStringLiteral(GetSymbol(), pos);
}
default:
DCHECK(false);
}
return FailureExpression();
}
Expression* Parser::NewV8Intrinsic(const AstRawString* name,
const ScopedPtrList<Expression>& args,
int pos) {
if (extension_ != nullptr) {
// The extension structures are only accessible while parsing the
// very first time, not when reparsing because of lazy compilation.
GetClosureScope()->ForceEagerCompilation();
}
DCHECK(name->is_one_byte());
const Runtime::Function* function =
Runtime::FunctionForName(name->raw_data(), name->length());
if (function != nullptr) {
// Check for possible name clash.
DCHECK_EQ(Context::kNotFound,
Context::IntrinsicIndexForName(name->raw_data(), name->length()));
// Check that the expected number of arguments are being passed.
if (function->nargs != -1 && function->nargs != args.length()) {
ReportMessage(MessageTemplate::kRuntimeWrongNumArgs);
return FailureExpression();
}
return factory()->NewCallRuntime(function, args, pos);
}
int context_index =
Context::IntrinsicIndexForName(name->raw_data(), name->length());
// Check that the function is defined.
if (context_index == Context::kNotFound) {
ReportMessage(MessageTemplate::kNotDefined, name);
return FailureExpression();
}
return factory()->NewCallRuntime(context_index, args, pos);
}
Parser::Parser(ParseInfo* info)
: ParserBase<Parser>(info->zone(), &scanner_, info->stack_limit(),
info->extension(), info->GetOrCreateAstValueFactory(),
info->pending_error_handler(),
info->runtime_call_stats(), info->logger(),
info->script().is_null() ? -1 : info->script()->id(),
info->is_module(), true),
info_(info),
scanner_(info->character_stream(), info->is_module()),
preparser_zone_(info->zone()->allocator(), ZONE_NAME),
reusable_preparser_(nullptr),
mode_(PARSE_EAGERLY), // Lazy mode must be set explicitly.
source_range_map_(info->source_range_map()),
target_stack_(nullptr),
total_preparse_skipped_(0),
consumed_preparse_data_(info->consumed_preparse_data()),
preparse_data_buffer_(),
parameters_end_pos_(info->parameters_end_pos()) {
// Even though we were passed ParseInfo, we should not store it in
// Parser - this makes sure that Isolate is not accidentally accessed via
// ParseInfo during background parsing.
DCHECK_NOT_NULL(info->character_stream());
// Determine if functions can be lazily compiled. This is necessary to
// allow some of our builtin JS files to be lazily compiled. These
// builtins cannot be handled lazily by the parser, since we have to know
// if a function uses the special natives syntax, which is something the
// parser records.
// If the debugger requests compilation for break points, we cannot be
// aggressive about lazy compilation, because it might trigger compilation
// of functions without an outer context when setting a breakpoint through
// Debug::FindSharedFunctionInfoInScript
// We also compile eagerly for kProduceExhaustiveCodeCache.
bool can_compile_lazily = info->allow_lazy_compile() && !info->is_eager();
set_default_eager_compile_hint(can_compile_lazily
? FunctionLiteral::kShouldLazyCompile
: FunctionLiteral::kShouldEagerCompile);
allow_lazy_ = info->allow_lazy_compile() && info->allow_lazy_parsing() &&
!info->is_native() && info->extension() == nullptr &&
can_compile_lazily;
set_allow_natives(info->allow_natives_syntax() || info->is_native());
set_allow_harmony_public_fields(info->allow_harmony_public_fields());
set_allow_harmony_static_fields(info->allow_harmony_static_fields());
set_allow_harmony_dynamic_import(info->allow_harmony_dynamic_import());
set_allow_harmony_import_meta(info->allow_harmony_import_meta());
set_allow_harmony_numeric_separator(info->allow_harmony_numeric_separator());
set_allow_harmony_private_fields(info->allow_harmony_private_fields());
set_allow_harmony_private_methods(info->allow_harmony_private_methods());
for (int feature = 0; feature < v8::Isolate::kUseCounterFeatureCount;
++feature) {
use_counts_[feature] = 0;
}
}
void Parser::InitializeEmptyScopeChain(ParseInfo* info) {
DCHECK_NULL(original_scope_);
DCHECK_NULL(info->script_scope());
DeclarationScope* script_scope = NewScriptScope();
info->set_script_scope(script_scope);
original_scope_ = script_scope;
}
void Parser::DeserializeScopeChain(
Isolate* isolate, ParseInfo* info,
MaybeHandle<ScopeInfo> maybe_outer_scope_info,
Scope::DeserializationMode mode) {
InitializeEmptyScopeChain(info);
Handle<ScopeInfo> outer_scope_info;
if (maybe_outer_scope_info.ToHandle(&outer_scope_info)) {
DCHECK(ThreadId::Current().Equals(isolate->thread_id()));
original_scope_ = Scope::DeserializeScopeChain(
isolate, zone(), *outer_scope_info, info->script_scope(),
ast_value_factory(), mode);
}
}
namespace {
void MaybeResetCharacterStream(ParseInfo* info, FunctionLiteral* literal) {
// Don't reset the character stream if there is an asm.js module since it will
// be used again by the asm-parser.
if (info->contains_asm_module()) {
if (FLAG_stress_validate_asm) return;
if (literal != nullptr && literal->scope()->ContainsAsmModule()) return;
}
info->ResetCharacterStream();
}
void MaybeProcessSourceRanges(ParseInfo* parse_info, Expression* root,
uintptr_t stack_limit_) {
if (root != nullptr && parse_info->source_range_map() != nullptr) {
SourceRangeAstVisitor visitor(stack_limit_, root,
parse_info->source_range_map());
visitor.Run();
}
}
} // namespace
FunctionLiteral* Parser::ParseProgram(Isolate* isolate, ParseInfo* info) {
// TODO(bmeurer): We temporarily need to pass allow_nesting = true here,
// see comment for HistogramTimerScope class.
// It's OK to use the Isolate & counters here, since this function is only
// called in the main thread.
DCHECK(parsing_on_main_thread_);
RuntimeCallTimerScope runtime_timer(
runtime_call_stats_, info->is_eval()
? RuntimeCallCounterId::kParseEval
: RuntimeCallCounterId::kParseProgram);
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.ParseProgram");
base::ElapsedTimer timer;
if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
// Initialize parser state.
DeserializeScopeChain(isolate, info, info->maybe_outer_scope_info(),
Scope::DeserializationMode::kIncludingVariables);
scanner_.Initialize();
if (FLAG_harmony_hashbang && !info->is_eval()) {
scanner_.SkipHashBang();
}
FunctionLiteral* result = DoParseProgram(isolate, info);
MaybeResetCharacterStream(info, result);
MaybeProcessSourceRanges(info, result, stack_limit_);
HandleSourceURLComments(isolate, info->script());
if (V8_UNLIKELY(FLAG_log_function_events) && result != nullptr) {
double ms = timer.Elapsed().InMillisecondsF();
const char* event_name = "parse-eval";
Script script = *info->script();
int start = -1;
int end = -1;
if (!info->is_eval()) {
event_name = "parse-script";
start = 0;
end = String::cast(script->source())->length();
}
LOG(isolate,
FunctionEvent(event_name, script->id(), ms, start, end, "", 0));
}
return result;
}
FunctionLiteral* Parser::DoParseProgram(Isolate* isolate, ParseInfo* info) {
// Note that this function can be called from the main thread or from a
// background thread. We should not access anything Isolate / heap dependent
// via ParseInfo, and also not pass it forward. If not on the main thread
// isolate will be nullptr.
DCHECK_EQ(parsing_on_main_thread_, isolate != nullptr);
DCHECK_NULL(scope_);
DCHECK_NULL(target_stack_);
ParsingModeScope mode(this, allow_lazy_ ? PARSE_LAZILY : PARSE_EAGERLY);
ResetFunctionLiteralId();
DCHECK(info->function_literal_id() == FunctionLiteral::kIdTypeTopLevel ||
info->function_literal_id() == FunctionLiteral::kIdTypeInvalid);
FunctionLiteral* result = nullptr;
{
Scope* outer = original_scope_;
DCHECK_NOT_NULL(outer);
if (info->is_eval()) {
outer = NewEvalScope(outer);
} else if (parsing_module_) {
DCHECK_EQ(outer, info->script_scope());
outer = NewModuleScope(info->script_scope());
}
DeclarationScope* scope = outer->AsDeclarationScope();
scope->set_start_position(0);
FunctionState function_state(&function_state_, &scope_, scope);
ScopedPtrList<Statement> body(pointer_buffer());
int beg_pos = scanner()->location().beg_pos;
if (parsing_module_) {
DCHECK(info->is_module());
// Declare the special module parameter.
auto name = ast_value_factory()->empty_string();
bool is_rest = false;
bool is_optional = false;
VariableMode mode = VariableMode::kVar;
bool was_added;
scope->DeclareLocal(name, mode, PARAMETER_VARIABLE, &was_added,
Variable::DefaultInitializationFlag(mode));
DCHECK(was_added);
auto var = scope->DeclareParameter(name, VariableMode::kVar, is_optional,
is_rest, ast_value_factory(), beg_pos);
var->AllocateTo(VariableLocation::PARAMETER, 0);
PrepareGeneratorVariables();
Expression* initial_yield =
BuildInitialYield(kNoSourcePosition, kGeneratorFunction);
body.Add(
factory()->NewExpressionStatement(initial_yield, kNoSourcePosition));
ParseModuleItemList(&body);
if (!has_error() &&
!module()->Validate(this->scope()->AsModuleScope(),
pending_error_handler(), zone())) {
scanner()->set_parser_error();
}
} else if (info->is_wrapped_as_function()) {
ParseWrapped(isolate, info, &body, scope, zone());
} else {
// Don't count the mode in the use counters--give the program a chance
// to enable script-wide strict mode below.
this->scope()->SetLanguageMode(info->language_mode());
ParseStatementList(&body, Token::EOS);
}
// The parser will peek but not consume EOS. Our scope logically goes all
// the way to the EOS, though.
scope->set_end_position(peek_position());
if (is_strict(language_mode())) {
CheckStrictOctalLiteral(beg_pos, end_position());
}
if (is_sloppy(language_mode())) {
// TODO(littledan): Function bindings on the global object that modify
// pre-existing bindings should be made writable, enumerable and
// nonconfigurable if possible, whereas this code will leave attributes
// unchanged if the property already exists.
InsertSloppyBlockFunctionVarBindings(scope);
}
// Internalize the ast strings in the case of eval so we can check for
// conflicting var declarations with outer scope-info-backed scopes.
if (info->is_eval()) {
DCHECK(parsing_on_main_thread_);
info->ast_value_factory()->Internalize(isolate);
}
CheckConflictingVarDeclarations(scope);
if (info->parse_restriction() == ONLY_SINGLE_FUNCTION_LITERAL) {
if (body.length() != 1 || !body.at(0)->IsExpressionStatement() ||
!body.at(0)
->AsExpressionStatement()
->expression()
->IsFunctionLiteral()) {
ReportMessage(MessageTemplate::kSingleFunctionLiteral);
}
}
int parameter_count = parsing_module_ ? 1 : 0;
result = factory()->NewScriptOrEvalFunctionLiteral(
scope, body, function_state.expected_property_count(), parameter_count);
result->set_suspend_count(function_state.suspend_count());
}
info->set_max_function_literal_id(GetLastFunctionLiteralId());
// Make sure the target stack is empty.
DCHECK_NULL(target_stack_);
if (has_error()) return nullptr;
return result;
}
ZonePtrList<const AstRawString>* Parser::PrepareWrappedArguments(
Isolate* isolate, ParseInfo* info, Zone* zone) {
DCHECK(parsing_on_main_thread_);
DCHECK_NOT_NULL(isolate);
Handle<FixedArray> arguments(info->script()->wrapped_arguments(), isolate);
int arguments_length = arguments->length();
ZonePtrList<const AstRawString>* arguments_for_wrapped_function =
new (zone) ZonePtrList<const AstRawString>(arguments_length, zone);
for (int i = 0; i < arguments_length; i++) {
const AstRawString* argument_string = ast_value_factory()->GetString(
Handle<String>(String::cast(arguments->get(i)), isolate));
arguments_for_wrapped_function->Add(argument_string, zone);
}
return arguments_for_wrapped_function;
}
void Parser::ParseWrapped(Isolate* isolate, ParseInfo* info,
ScopedPtrList<Statement>* body,
DeclarationScope* outer_scope, Zone* zone) {
DCHECK_EQ(parsing_on_main_thread_, isolate != nullptr);
DCHECK(info->is_wrapped_as_function());
ParsingModeScope parsing_mode(this, PARSE_EAGERLY);
// Set function and block state for the outer eval scope.
DCHECK(outer_scope->is_eval_scope());
FunctionState function_state(&function_state_, &scope_, outer_scope);
const AstRawString* function_name = nullptr;
Scanner::Location location(0, 0);
ZonePtrList<const AstRawString>* arguments_for_wrapped_function =
PrepareWrappedArguments(isolate, info, zone);
FunctionLiteral* function_literal = ParseFunctionLiteral(
function_name, location, kSkipFunctionNameCheck, kNormalFunction,
kNoSourcePosition, FunctionLiteral::kWrapped, LanguageMode::kSloppy,
arguments_for_wrapped_function);
Statement* return_statement = factory()->NewReturnStatement(
function_literal, kNoSourcePosition, kNoSourcePosition);
body->Add(return_statement);
}
FunctionLiteral* Parser::ParseFunction(Isolate* isolate, ParseInfo* info,
Handle<SharedFunctionInfo> shared_info) {
// It's OK to use the Isolate & counters here, since this function is only
// called in the main thread.
DCHECK(parsing_on_main_thread_);
RuntimeCallTimerScope runtime_timer(runtime_call_stats_,
RuntimeCallCounterId::kParseFunction);
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.ParseFunction");
base::ElapsedTimer timer;
if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
DeserializeScopeChain(isolate, info, info->maybe_outer_scope_info(),
Scope::DeserializationMode::kIncludingVariables);
DCHECK_EQ(factory()->zone(), info->zone());
// Initialize parser state.
Handle<String> name(shared_info->Name(), isolate);
info->set_function_name(ast_value_factory()->GetString(name));
scanner_.Initialize();
FunctionLiteral* result =
DoParseFunction(isolate, info, info->function_name());
MaybeResetCharacterStream(info, result);
MaybeProcessSourceRanges(info, result, stack_limit_);
if (result != nullptr) {
Handle<String> inferred_name(shared_info->inferred_name(), isolate);
result->set_inferred_name(inferred_name);
}
if (V8_UNLIKELY(FLAG_log_function_events) && result != nullptr) {
double ms = timer.Elapsed().InMillisecondsF();
// We need to make sure that the debug-name is available.
ast_value_factory()->Internalize(isolate);
DeclarationScope* function_scope = result->scope();
std::unique_ptr<char[]> function_name = result->GetDebugName();
LOG(isolate,
FunctionEvent("parse-function", info->script()->id(), ms,
function_scope->start_position(),
function_scope->end_position(), function_name.get(),
strlen(function_name.get())));
}
return result;
}
static FunctionLiteral::FunctionType ComputeFunctionType(ParseInfo* info) {
if (info->is_wrapped_as_function()) {
return FunctionLiteral::kWrapped;
} else if (info->is_declaration()) {
return FunctionLiteral::kDeclaration;
} else if (info->is_named_expression()) {
return FunctionLiteral::kNamedExpression;
} else if (IsConciseMethod(info->function_kind()) ||
IsAccessorFunction(info->function_kind())) {
return FunctionLiteral::kAccessorOrMethod;
}
return FunctionLiteral::kAnonymousExpression;
}
FunctionLiteral* Parser::DoParseFunction(Isolate* isolate, ParseInfo* info,
const AstRawString* raw_name) {
DCHECK_EQ(parsing_on_main_thread_, isolate != nullptr);
DCHECK_NOT_NULL(raw_name);
DCHECK_NULL(scope_);
DCHECK_NULL(target_stack_);
DCHECK(ast_value_factory());
fni_.PushEnclosingName(raw_name);
ResetFunctionLiteralId();
DCHECK_LT(0, info->function_literal_id());
SkipFunctionLiterals(info->function_literal_id() - 1);
ParsingModeScope parsing_mode(this, PARSE_EAGERLY);
// Place holder for the result.
FunctionLiteral* result = nullptr;
{
// Parse the function literal.
Scope* outer = original_scope_;
DeclarationScope* outer_function = outer->GetClosureScope();
DCHECK(outer);
FunctionState function_state(&function_state_, &scope_, outer_function);
BlockState block_state(&scope_, outer);
DCHECK(is_sloppy(outer->language_mode()) ||
is_strict(info->language_mode()));
FunctionLiteral::FunctionType function_type = ComputeFunctionType(info);
FunctionKind kind = info->function_kind();
if (IsArrowFunction(kind)) {
if (IsAsyncFunction(kind)) {
DCHECK(!scanner()->HasLineTerminatorAfterNext());
if (!Check(Token::ASYNC)) {
CHECK(stack_overflow());
return nullptr;
}
if (!(peek_any_identifier() || peek() == Token::LPAREN)) {
CHECK(stack_overflow());
return nullptr;
}
}
// TODO(adamk): We should construct this scope from the ScopeInfo.
DeclarationScope* scope = NewFunctionScope(kind);
scope->set_has_checked_syntax(true);
// This bit only needs to be explicitly set because we're
// not passing the ScopeInfo to the Scope constructor.
SetLanguageMode(scope, info->language_mode());
scope->set_start_position(info->start_position());
ParserFormalParameters formals(scope);
{
ParameterDeclarationParsingScope formals_scope(this);
// Parsing patterns as variable reference expression creates
// NewUnresolved references in current scope. Enter arrow function
// scope for formal parameter parsing.
BlockState block_state(&scope_, scope);
if (Check(Token::LPAREN)) {
// '(' StrictFormalParameters ')'
ParseFormalParameterList(&formals);
Expect(Token::RPAREN);
} else {
// BindingIdentifier
ParameterParsingScope scope(impl(), &formals);
ParseFormalParameter(&formals);
DeclareFormalParameters(&formals);
}
formals.duplicate_loc = formals_scope.duplicate_location();
}
if (GetLastFunctionLiteralId() != info->function_literal_id() - 1) {
if (has_error()) return nullptr;
// If there were FunctionLiterals in the parameters, we need to
// renumber them to shift down so the next function literal id for
// the arrow function is the one requested.
AstFunctionLiteralIdReindexer reindexer(
stack_limit_,
(info->function_literal_id() - 1) - GetLastFunctionLiteralId());
for (auto p : formals.params) {
if (p->pattern != nullptr) reindexer.Reindex(p->pattern);
if (p->initializer() != nullptr) {
reindexer.Reindex(p->initializer());
}
}
ResetFunctionLiteralId();
SkipFunctionLiterals(info->function_literal_id() - 1);
}
Expression* expression = ParseArrowFunctionLiteral(formals);
// Scanning must end at the same position that was recorded
// previously. If not, parsing has been interrupted due to a stack
// overflow, at which point the partially parsed arrow function
// concise body happens to be a valid expression. This is a problem
// only for arrow functions with single expression bodies, since there
// is no end token such as "}" for normal functions.
if (scanner()->location().end_pos == info->end_position()) {
// The pre-parser saw an arrow function here, so the full parser
// must produce a FunctionLiteral.
DCHECK(expression->IsFunctionLiteral());
result = expression->AsFunctionLiteral();
}
} else if (IsDefaultConstructor(kind)) {
DCHECK_EQ(scope(), outer);
result = DefaultConstructor(raw_name, IsDerivedConstructor(kind),
info->start_position(), info->end_position());
} else {
ZonePtrList<const AstRawString>* arguments_for_wrapped_function =
info->is_wrapped_as_function()
? PrepareWrappedArguments(isolate, info, zone())
: nullptr;
result = ParseFunctionLiteral(
raw_name, Scanner::Location::invalid(), kSkipFunctionNameCheck, kind,
kNoSourcePosition, function_type, info->language_mode(),
arguments_for_wrapped_function);
}
if (has_error()) return nullptr;
result->set_requires_instance_members_initializer(
info->requires_instance_members_initializer());
if (info->is_oneshot_iife()) {
result->mark_as_oneshot_iife();
}
}
// Make sure the target stack is empty.
DCHECK_NULL(target_stack_);
DCHECK_IMPLIES(result,
info->function_literal_id() == result->function_literal_id());
return result;
}
Statement* Parser::ParseModuleItem() {
// ecma262/#prod-ModuleItem
// ModuleItem :
// ImportDeclaration
// ExportDeclaration
// StatementListItem
Token::Value next = peek();
if (next == Token::EXPORT) {
return ParseExportDeclaration();
}
if (next == Token::IMPORT) {
// We must be careful not to parse a dynamic import expression as an import
// declaration. Same for import.meta expressions.
Token::Value peek_ahead = PeekAhead();
if ((!allow_harmony_dynamic_import() || peek_ahead != Token::LPAREN) &&
(!allow_harmony_import_meta() || peek_ahead != Token::PERIOD)) {
ParseImportDeclaration();
return factory()->EmptyStatement();
}
}
return ParseStatementListItem();
}
void Parser::ParseModuleItemList(ScopedPtrList<Statement>* body) {
// ecma262/#prod-Module
// Module :
// ModuleBody?
//
// ecma262/#prod-ModuleItemList
// ModuleBody :
// ModuleItem*
DCHECK(scope()->is_module_scope());
while (peek() != Token::EOS) {
Statement* stat = ParseModuleItem();
if (stat == nullptr) return;
if (stat->IsEmptyStatement()) continue;
body->Add(stat);
}
}
const AstRawString* Parser::ParseModuleSpecifier() {
// ModuleSpecifier :
// StringLiteral
Expect(Token::STRING);
return GetSymbol();
}
ZoneChunkList<Parser::ExportClauseData>* Parser::ParseExportClause(
Scanner::Location* reserved_loc) {
// ExportClause :
// '{' '}'
// '{' ExportsList '}'
// '{' ExportsList ',' '}'
//
// ExportsList :
// ExportSpecifier
// ExportsList ',' ExportSpecifier
//
// ExportSpecifier :
// IdentifierName
// IdentifierName 'as' IdentifierName
ZoneChunkList<ExportClauseData>* export_data =
new (zone()) ZoneChunkList<ExportClauseData>(zone());
Expect(Token::LBRACE);
Token::Value name_tok;
while ((name_tok = peek()) != Token::RBRACE) {
// Keep track of the first reserved word encountered in case our
// caller needs to report an error.
if (!reserved_loc->IsValid() &&
!Token::IsValidIdentifier(name_tok, LanguageMode::kStrict, false,
parsing_module_)) {
*reserved_loc = scanner()->location();
}
const AstRawString* local_name = ParsePropertyName();
const AstRawString* export_name = nullptr;
Scanner::Location location = scanner()->location();
if (CheckContextualKeyword(ast_value_factory()->as_string())) {
export_name = ParsePropertyName();
// Set the location to the whole "a as b" string, so that it makes sense
// both for errors due to "a" and for errors due to "b".
location.end_pos = scanner()->location().end_pos;
}
if (export_name == nullptr) {
export_name = local_name;
}
export_data->push_back({export_name, local_name, location});
if (peek() == Token::RBRACE) break;
if (V8_UNLIKELY(!Check(Token::COMMA))) {
ReportUnexpectedToken(Next());
break;
}
}
Expect(Token::RBRACE);
return export_data;
}
ZonePtrList<const Parser::NamedImport>* Parser::ParseNamedImports(int pos) {
// NamedImports :
// '{' '}'
// '{' ImportsList '}'
// '{' ImportsList ',' '}'
//
// ImportsList :
// ImportSpecifier
// ImportsList ',' ImportSpecifier
//
// ImportSpecifier :
// BindingIdentifier
// IdentifierName 'as' BindingIdentifier
Expect(Token::LBRACE);
auto result = new (zone()) ZonePtrList<const NamedImport>(1, zone());
while (peek() != Token::RBRACE) {
const AstRawString* import_name = ParsePropertyName();
const AstRawString* local_name = import_name;
Scanner::Location location = scanner()->location();
// In the presence of 'as', the left-side of the 'as' can
// be any IdentifierName. But without 'as', it must be a valid
// BindingIdentifier.
if (CheckContextualKeyword(ast_value_factory()->as_string())) {
local_name = ParsePropertyName();
}
if (!Token::IsValidIdentifier(scanner()->current_token(),
LanguageMode::kStrict, false,
parsing_module_)) {
ReportMessage(MessageTemplate::kUnexpectedReserved);
return nullptr;
} else if (IsEvalOrArguments(local_name)) {
ReportMessage(MessageTemplate::kStrictEvalArguments);
return nullptr;
}
DeclareUnboundVariable(local_name, VariableMode::kConst,
kNeedsInitialization, position());
NamedImport* import =
new (zone()) NamedImport(import_name, local_name, location);
result->Add(import, zone());
if (peek() == Token::RBRACE) break;
Expect(Token::COMMA);
}
Expect(Token::RBRACE);
return result;
}
void Parser::ParseImportDeclaration() {
// ImportDeclaration :
// 'import' ImportClause 'from' ModuleSpecifier ';'
// 'import' ModuleSpecifier ';'
//
// ImportClause :
// ImportedDefaultBinding
// NameSpaceImport
// NamedImports
// ImportedDefaultBinding ',' NameSpaceImport
// ImportedDefaultBinding ',' NamedImports
//
// NameSpaceImport :
// '*' 'as' ImportedBinding
int pos = peek_position();
Expect(Token::IMPORT);
Token::Value tok = peek();
// 'import' ModuleSpecifier ';'
if (tok == Token::STRING) {
Scanner::Location specifier_loc = scanner()->peek_location();
const AstRawString* module_specifier = ParseModuleSpecifier();
ExpectSemicolon();
module()->AddEmptyImport(module_specifier, specifier_loc);
return;
}
// Parse ImportedDefaultBinding if present.
const AstRawString* import_default_binding = nullptr;
Scanner::Location import_default_binding_loc;
if (tok != Token::MUL && tok != Token::LBRACE) {
import_default_binding = ParseNonRestrictedIdentifier();
import_default_binding_loc = scanner()->location();
DeclareUnboundVariable(import_default_binding, VariableMode::kConst,
kNeedsInitialization, pos);
}
// Parse NameSpaceImport or NamedImports if present.
const AstRawString* module_namespace_binding = nullptr;
Scanner::Location module_namespace_binding_loc;
const ZonePtrList<const NamedImport>* named_imports = nullptr;
if (import_default_binding == nullptr || Check(Token::COMMA)) {
switch (peek()) {
case Token::MUL: {
Consume(Token::MUL);
ExpectContextualKeyword(ast_value_factory()->as_string());
module_namespace_binding = ParseNonRestrictedIdentifier();
module_namespace_binding_loc = scanner()->location();
DeclareUnboundVariable(module_namespace_binding, VariableMode::kConst,
kCreatedInitialized, pos);
break;
}
case Token::LBRACE:
named_imports = ParseNamedImports(pos);
break;
default:
ReportUnexpectedToken(scanner()->current_token());
return;
}
}
ExpectContextualKeyword(ast_value_factory()->from_string());
Scanner::Location specifier_loc = scanner()->peek_location();
const AstRawString* module_specifier = ParseModuleSpecifier();
ExpectSemicolon();
// Now that we have all the information, we can make the appropriate
// declarations.
// TODO(neis): Would prefer to call DeclareVariable for each case below rather
// than above and in ParseNamedImports, but then a possible error message
// would point to the wrong location. Maybe have a DeclareAt version of
// Declare that takes a location?
if (module_namespace_binding != nullptr) {
module()->AddStarImport(module_namespace_binding, module_specifier,
module_namespace_binding_loc, specifier_loc,
zone());
}
if (import_default_binding != nullptr) {
module()->AddImport(ast_value_factory()->default_string(),
import_default_binding, module_specifier,
import_default_binding_loc, specifier_loc, zone());
}
if (named_imports != nullptr) {
if (named_imports->length() == 0) {
module()->AddEmptyImport(module_specifier, specifier_loc);
} else {
for (int i = 0; i < named_imports->length(); ++i) {
const NamedImport* import = named_imports->at(i);
module()->AddImport(import->import_name, import->local_name,
module_specifier, import->location, specifier_loc,
zone());
}
}
}
}
Statement* Parser::ParseExportDefault() {
// Supports the following productions, starting after the 'default' token:
// 'export' 'default' HoistableDeclaration
// 'export' 'default' ClassDeclaration
// 'export' 'default' AssignmentExpression[In] ';'
Expect(Token::DEFAULT);
Scanner::Location default_loc = scanner()->location();
ZonePtrList<const AstRawString> local_names(1, zone());
Statement* result = nullptr;
switch (peek()) {
case Token::FUNCTION:
result = ParseHoistableDeclaration(&local_names, true);
break;
case Token::CLASS:
Consume(Token::CLASS);
result = ParseClassDeclaration(&local_names, true);
break;
case Token::ASYNC:
if (PeekAhead() == Token::FUNCTION &&
!scanner()->HasLineTerminatorAfterNext()) {
Consume(Token::ASYNC);
result = ParseAsyncFunctionDeclaration(&local_names, true);
break;
}
V8_FALLTHROUGH;
default: {
int pos = position();
AcceptINScope scope(this, true);
Expression* value = ParseAssignmentExpression();
SetFunctionName(value, ast_value_factory()->default_string());
const AstRawString* local_name =
ast_value_factory()->star_default_star_string();
local_names.Add(local_name, zone());
// It's fine to declare this as VariableMode::kConst because the user has
// no way of writing to it.
VariableProxy* proxy =
DeclareBoundVariable(local_name, VariableMode::kConst, pos);
proxy->var()->set_initializer_position(position());
Assignment* assignment = factory()->NewAssignment(
Token::INIT, proxy, value, kNoSourcePosition);
result = IgnoreCompletion(
factory()->NewExpressionStatement(assignment, kNoSourcePosition));
ExpectSemicolon();
break;
}
}
if (result != nullptr) {
DCHECK_EQ(local_names.length(), 1);
module()->AddExport(local_names.first(),
ast_value_factory()->default_string(), default_loc,
zone());
}
return result;
}
const AstRawString* Parser::NextInternalNamespaceExportName() {
const char* prefix = ".ns-export";
std::string s(prefix);
s.append(std::to_string(number_of_named_namespace_exports_++));
return ast_value_factory()->GetOneByteString(s.c_str());
}
void Parser::ParseExportStar() {
int pos = position();
Consume(Token::MUL);
if (!FLAG_harmony_namespace_exports ||
!PeekContextualKeyword(ast_value_factory()->as_string())) {
// 'export' '*' 'from' ModuleSpecifier ';'
Scanner::Location loc = scanner()->location();
ExpectContextualKeyword(ast_value_factory()->from_string());
Scanner::Location specifier_loc = scanner()->peek_location();
const AstRawString* module_specifier = ParseModuleSpecifier();
ExpectSemicolon();
module()->AddStarExport(module_specifier, loc, specifier_loc, zone());
return;
}
if (!FLAG_harmony_namespace_exports) return;
// 'export' '*' 'as' IdentifierName 'from' ModuleSpecifier ';'
//
// Desugaring:
// export * as x from "...";
// ~>
// import * as .x from "..."; export {.x as x};
ExpectContextualKeyword(ast_value_factory()->as_string());
const AstRawString* export_name = ParsePropertyName();
Scanner::Location export_name_loc = scanner()->location();
const AstRawString* local_name = NextInternalNamespaceExportName();
Scanner::Location local_name_loc = Scanner::Location::invalid();
DeclareUnboundVariable(local_name, VariableMode::kConst, kCreatedInitialized,
pos);
ExpectContextualKeyword(ast_value_factory()->from_string());
Scanner::Location specifier_loc = scanner()->peek_location();
const AstRawString* module_specifier = ParseModuleSpecifier();
ExpectSemicolon();
module()->AddStarImport(local_name, module_specifier, local_name_loc,
specifier_loc, zone());
module()->AddExport(local_name, export_name, export_name_loc, zone());
}
Statement* Parser::ParseExportDeclaration() {
// ExportDeclaration:
// 'export' '*' 'from' ModuleSpecifier ';'
// 'export' '*' 'as' IdentifierName 'from' ModuleSpecifier ';'
// 'export' ExportClause ('from' ModuleSpecifier)? ';'
// 'export' VariableStatement
// 'export' Declaration
// 'export' 'default' ... (handled in ParseExportDefault)
Expect(Token::EXPORT);
Statement* result = nullptr;
ZonePtrList<const AstRawString> names(1, zone());
Scanner::Location loc = scanner()->peek_location();
switch (peek()) {
case Token::DEFAULT:
return ParseExportDefault();
case Token::MUL:
ParseExportStar();
return factory()->EmptyStatement();
case Token::LBRACE: {
// There are two cases here:
//
// 'export' ExportClause ';'
// and
// 'export' ExportClause FromClause ';'
//
// In the first case, the exported identifiers in ExportClause must
// not be reserved words, while in the latter they may be. We
// pass in a location that gets filled with the first reserved word
// encountered, and then throw a SyntaxError if we are in the
// non-FromClause case.
Scanner::Location reserved_loc = Scanner::Location::invalid();
ZoneChunkList<ExportClauseData>* export_data =
ParseExportClause(&reserved_loc);
const AstRawString* module_specifier = nullptr;
Scanner::Location specifier_loc;
if (CheckContextualKeyword(ast_value_factory()->from_string())) {
specifier_loc = scanner()->peek_location();
module_specifier = ParseModuleSpecifier();
} else if (reserved_loc.IsValid()) {
// No FromClause, so reserved words are invalid in ExportClause.
ReportMessageAt(reserved_loc, MessageTemplate::kUnexpectedReserved);
return nullptr;
}
ExpectSemicolon();
if (module_specifier == nullptr) {
for (const ExportClauseData& data : *export_data) {
module()->AddExport(data.local_name, data.export_name, data.location,
zone());
}
} else if (export_data->is_empty()) {
module()->AddEmptyImport(module_specifier, specifier_loc);
} else {
for (const ExportClauseData& data : *export_data) {
module()->AddExport(data.local_name, data.export_name,
module_specifier, data.location, specifier_loc,
zone());
}
}
return factory()->EmptyStatement();
}
case Token::FUNCTION:
result = ParseHoistableDeclaration(&names, false);
break;
case Token::CLASS:
Consume(Token::CLASS);
result = ParseClassDeclaration(&names, false);
break;
case Token::VAR:
case Token::LET:
case Token::CONST:
result = ParseVariableStatement(kStatementListItem, &names);
break;
case Token::ASYNC:
Consume(Token::ASYNC);
if (peek() == Token::FUNCTION &&
!scanner()->HasLineTerminatorBeforeNext()) {
result = ParseAsyncFunctionDeclaration(&names, false);
break;
}
V8_FALLTHROUGH;
default:
ReportUnexpectedToken(scanner()->current_token());
return nullptr;
}
loc.end_pos = scanner()->location().end_pos;
ModuleDescriptor* descriptor = module();
for (int i = 0; i < names.length(); ++i) {
descriptor->AddExport(names[i], names[i], loc, zone());
}
return result;
}
void Parser::DeclareUnboundVariable(const AstRawString* name, VariableMode mode,
InitializationFlag init, int pos) {
bool was_added;
Variable* var = DeclareVariable(name, NORMAL_VARIABLE, mode, init, scope(),
&was_added, pos, end_position());
// The variable will be added to the declarations list, but since we are not
// binding it to anything, we can simply ignore it here.
USE(var);
}
VariableProxy* Parser::DeclareBoundVariable(const AstRawString* name,
VariableMode mode, int pos) {
DCHECK_NOT_NULL(name);
VariableProxy* proxy =
factory()->NewVariableProxy(name, NORMAL_VARIABLE, position());
bool was_added;
Variable* var = DeclareVariable(name, NORMAL_VARIABLE, mode,
Variable::DefaultInitializationFlag(mode),
scope(), &was_added, pos, end_position());
proxy->BindTo(var);
return proxy;
}
void Parser::DeclareAndBindVariable(VariableProxy* proxy, VariableKind kind,
VariableMode mode, InitializationFlag init,
Scope* scope, bool* was_added, int begin,
int end) {
Variable* var = DeclareVariable(proxy->raw_name(), kind, mode, init, scope,
was_added, begin, end);
proxy->BindTo(var);
}
Variable* Parser::DeclareVariable(const AstRawString* name, VariableKind kind,
VariableMode mode, InitializationFlag init,
Scope* scope, bool* was_added, int begin,
int end) {
Declaration* declaration;
if (mode == VariableMode::kVar && !scope->is_declaration_scope()) {
DCHECK(scope->is_block_scope() || scope->is_with_scope());
declaration = factory()->NewNestedVariableDeclaration(scope, begin);
} else {
declaration = factory()->NewVariableDeclaration(begin);
}
Declare(declaration, name, kind, mode, init, scope, was_added, begin, end);
return declaration->var();
}
void Parser::Declare(Declaration* declaration, const AstRawString* name,
VariableKind variable_kind, VariableMode mode,
InitializationFlag init, Scope* scope, bool* was_added,
int var_begin_pos, int var_end_pos) {
bool local_ok = true;
bool sloppy_mode_block_scope_function_redefinition = false;
scope->DeclareVariable(
declaration, name, var_begin_pos, mode, variable_kind, init, was_added,
&sloppy_mode_block_scope_function_redefinition, &local_ok);
if (!local_ok) {
// If we only have the start position of a proxy, we can't highlight the
// whole variable name. Pretend its length is 1 so that we highlight at
// least the first character.
Scanner::Location loc(var_begin_pos, var_end_pos != kNoSourcePosition
? var_end_pos
: var_begin_pos + 1);
if (variable_kind == PARAMETER_VARIABLE) {
ReportMessageAt(loc, MessageTemplate::kParamDupe);
} else {
ReportMessageAt(loc, MessageTemplate::kVarRedeclaration,
declaration->var()->raw_name());
}
} else if (sloppy_mode_block_scope_function_redefinition) {
++use_counts_[v8::Isolate::kSloppyModeBlockScopedFunctionRedefinition];
}
}
Statement* Parser::BuildInitializationBlock(
DeclarationParsingResult* parsing_result) {
ScopedPtrList<Statement> statements(pointer_buffer());
for (const auto& declaration : parsing_result->declarations) {
if (!declaration.initializer) continue;
InitializeVariables(&statements, parsing_result->descriptor.kind,
&declaration);
}
return factory()->NewBlock(true, statements);
}
Statement* Parser::DeclareFunction(const AstRawString* variable_name,
FunctionLiteral* function, VariableMode mode,
VariableKind kind, int beg_pos, int end_pos,
ZonePtrList<const AstRawString>* names) {
Declaration* declaration =
factory()->NewFunctionDeclaration(function, beg_pos);
bool was_added;
Declare(declaration, variable_name, kind, mode, kCreatedInitialized, scope(),
&was_added, beg_pos);
if (names) names->Add(variable_name, zone());
if (kind == SLOPPY_BLOCK_FUNCTION_VARIABLE) {
Token::Value init = loop_nesting_depth() > 0 ? Token::ASSIGN : Token::INIT;
SloppyBlockFunctionStatement* statement =
factory()->NewSloppyBlockFunctionStatement(end_pos, declaration->var(),
init);
GetDeclarationScope()->DeclareSloppyBlockFunction(statement);
return statement;
}
return factory()->EmptyStatement();
}
Statement* Parser::DeclareClass(const AstRawString* variable_name,
Expression* value,
ZonePtrList<const AstRawString>* names,
int class_token_pos, int end_pos) {
VariableProxy* proxy =
DeclareBoundVariable(variable_name, VariableMode::kLet, class_token_pos);
proxy->var()->set_initializer_position(end_pos);
if (names) names->Add(variable_name, zone());
Assignment* assignment =
factory()->NewAssignment(Token::INIT, proxy, value, class_token_pos);
return IgnoreCompletion(
factory()->NewExpressionStatement(assignment, kNoSourcePosition));
}
Statement* Parser::DeclareNative(const AstRawString* name, int pos) {
// 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.
GetClosureScope()->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 = DeclareBoundVariable(name, VariableMode::kVar, pos);
NativeFunctionLiteral* lit =
factory()->NewNativeFunctionLiteral(name, extension_, kNoSourcePosition);
return factory()->NewExpressionStatement(
factory()->NewAssignment(Token::INIT, proxy, lit, kNoSourcePosition),
pos);
}
void Parser::DeclareLabel(ZonePtrList<const AstRawString>** labels,
ZonePtrList<const AstRawString>** own_labels,
VariableProxy* var) {
DCHECK(IsIdentifier(var));
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)) {
ReportMessage(MessageTemplate::kLabelRedeclaration, label);
return;
}
// Add {label} to both {labels} and {own_labels}.
if (*labels == nullptr) {
DCHECK_NULL(*own_labels);
*labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
*own_labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
} else {
if (*own_labels == nullptr) {
*own_labels = new (zone()) ZonePtrList<const AstRawString>(1, zone());
}
}
(*labels)->Add(label, zone());
(*own_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()->DeleteUnresolved(var);
}
bool Parser::ContainsLabel(ZonePtrList<const AstRawString>* labels,
const AstRawString* label) {
DCHECK_NOT_NULL(label);
if (labels != nullptr) {
for (int i = labels->length(); i-- > 0;) {
if (labels->at(i) == label) return true;
}
}
return false;
}
Block* Parser::IgnoreCompletion(Statement* statement) {
Block* block = factory()->NewBlock(1, true);
block->statements()->Add(statement, zone());
return block;
}
Expression* Parser::RewriteReturn(Expression* return_value, int pos) {
if (IsDerivedConstructor(function_state_->kind())) {
// For subclass constructors we need to return this in case of undefined;
// other primitive values trigger an exception in the ConstructStub.
//
// return expr;
//
// Is rewritten as:
//
// return (temp = expr) === undefined ? this : temp;
// temp = expr
Variable* temp = NewTemporary(ast_value_factory()->empty_string());
Assignment* assign = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(temp), return_value, pos);
// temp === undefined
Expression* is_undefined = factory()->NewCompareOperation(
Token::EQ_STRICT, assign,
factory()->NewUndefinedLiteral(kNoSourcePosition), pos);
// is_undefined ? this : temp
return_value =
factory()->NewConditional(is_undefined, ThisExpression(pos),
factory()->NewVariableProxy(temp), pos);
}
return return_value;
}
Statement* Parser::RewriteSwitchStatement(SwitchStatement* switch_statement,
Scope* scope) {
// In order to get the CaseClauses to execute in their own lexical scope,
// but without requiring downstream code to have special scope handling
// code for switch statements, desugar into blocks as follows:
// { // To group the statements--harmless to evaluate Expression in scope
// .tag_variable = Expression;
// { // To give CaseClauses a scope
// switch (.tag_variable) { CaseClause* }
// }
// }
DCHECK_NOT_NULL(scope);
DCHECK(scope->is_block_scope());
DCHECK_GE(switch_statement->position(), scope->start_position());
DCHECK_LT(switch_statement->position(), scope->end_position());
Block* switch_block = factory()->NewBlock(2, false);
Expression* tag = switch_statement->tag();
Variable* tag_variable =
NewTemporary(ast_value_factory()->dot_switch_tag_string());
Assignment* tag_assign = factory()->NewAssignment(
Token::ASSIGN, factory()->NewVariableProxy(tag_variable), tag,
tag->position());
// Wrap with IgnoreCompletion so the tag isn't returned as the completion
// value, in case the switch statements don't have a value.
Statement* tag_statement = IgnoreCompletion(
factory()->NewExpressionStatement(tag_assign, kNoSourcePosition));
switch_block->statements()->Add(tag_statement, zone());
switch_statement->set_tag(factory()->NewVariableProxy(tag_variable));
Block* cases_block = factory()->NewBlock(1, false);
cases_block->statements()->Add(switch_statement, zone());
cases_block->set_scope(scope);
switch_block->statements()->Add(cases_block, zone());
return switch_block;
}
void Parser::InitializeVariables(
ScopedPtrList<Statement>* statements, VariableKind kind,
const DeclarationParsingResult::Declaration* declaration) {
if (has_error()) return;
DCHECK_NOT_NULL(declaration->initializer);
int pos = declaration->value_beg_pos;
if (pos == kNoSourcePosition) {
pos = declaration->initializer->position();
}
Assignment* assignment = factory()->NewAssignment(
Token::INIT, declaration->pattern, declaration->initializer, pos);
statements->Add(factory()->NewExpressionStatement(assignment, pos));
}
Block* Parser::RewriteCatchPattern(CatchInfo* catch_info) {
DCHECK_NOT_NULL(catch_info->pattern);
DeclarationParsingResult::Declaration decl(
catch_info->pattern, factory()->NewVariableProxy(catch_info->variable));
ScopedPtrList<Statement> init_statements(pointer_buffer());
InitializeVariables(&init_statements, NORMAL_VARIABLE, &decl);
return factory()->NewBlock(true, init_statements);
}
void Parser::ReportVarRedeclarationIn(const AstRawString* name, Scope* scope) {
for (Declaration* decl : *scope->declarations()) {
if (decl->var()->raw_name() == name) {
int position = decl->position();
Scanner::Location location =
position == kNoSourcePosition
? Scanner::Location::invalid()
: Scanner::Location(position, position + name->length());
ReportMessageAt(location, MessageTemplate::kVarRedeclaration, name);
return;
}
}
UNREACHABLE();
}
Statement* Parser::RewriteTryStatement(Block* try_block, Block* catch_block,
const SourceRange& catch_range,
Block* finally_block,
const SourceRange& finally_range,
const CatchInfo& catch_info, int pos) {
// Simplify the AST nodes by converting:
// 'try B0 catch B1 finally B2'
// to:
// 'try { try B0 catch B1 } finally B2'
if (catch_block != nullptr && finally_block != nullptr) {
// If we have both, create an inner try/catch.
TryCatchStatement* statement;
statement = factory()->NewTryCatchStatement(try_block, catch_info.scope,
catch_block, kNoSourcePosition);
RecordTryCatchStatementSourceRange(statement, catch_range);
try_block = factory()->NewBlock(1, false);
try_block->statements()->Add(statement, zone());
catch_block = nullptr; // Clear to indicate it's been handled.
}
if (catch_block != nullptr) {
DCHECK_NULL(finally_block);
TryCatchStatement* stmt = factory()->NewTryCatchStatement(
try_block, catch_info.scope, catch_block, pos);
RecordTryCatchStatementSourceRange(stmt, catch_range);
return stmt;
} else {
DCHECK_NOT_NULL(finally_block);
TryFinallyStatement* stmt =
factory()->NewTryFinallyStatement(try_block, finally_block, pos);
RecordTryFinallyStatementSourceRange(stmt, finally_range);
return stmt;
}
}
void Parser::ParseAndRewriteGeneratorFunctionBody(
int pos, FunctionKind kind, ScopedPtrList<Statement>* body) {
// For ES6 Generators, we just prepend the initial yield.
Expression* initial_yield = BuildInitialYield(pos, kind);
body->Add(
factory()->NewExpressionStatement(initial_yield, kNoSourcePosition));
ParseStatementList(body, Token::RBRACE);
}
void Parser::ParseAndRewriteAsyncGeneratorFunctionBody(
int pos, FunctionKind kind, ScopedPtrList<Statement>* body) {
// For ES2017 Async Generators, we produce:
//
// try {
// InitialYield;
// ...body...;
// return undefined; // See comment below
// } catch (.catch) {
// %AsyncGeneratorReject(generator, .catch);
// } finally {
// %_GeneratorClose(generator);
// }
//
// - InitialYield yields the actual generator object.
// - Any return statement inside the body will have its argument wrapped
// in an iterator result object with a "done" property set to `true`.
// - If the generator terminates for whatever reason, we must close it.
// Hence the finally clause.
// - BytecodeGenerator performs special handling for ReturnStatements in
// async generator functions, resolving the appropriate Promise with an
// "done" iterator result object containing a Promise-unwrapped value.
DCHECK(IsAsyncGeneratorFunction(kind));
Block* try_block;
{
ScopedPtrList<Statement> statements(pointer_buffer());
Expression* initial_yield = BuildInitialYield(pos, kind);
statements.Add(
factory()->NewExpressionStatement(initial_yield, kNoSourcePosition));
ParseStatementList(&statements, Token::RBRACE);
// Don't create iterator result for async generators, as the resume methods
// will create it.
// TODO(leszeks): This will create another suspend point, which is
// unnecessary if there is already an unconditional return in the body.
Statement* final_return = BuildReturnStatement(
factory()->NewUndefinedLiteral(kNoSourcePosition), kNoSourcePosition);
statements.Add(final_return);
try_block = factory()->NewBlock(false, statements);
}
// For AsyncGenerators, a top-level catch block will reject the Promise.
Scope* catch_scope = NewHiddenCatchScope();
Block* catch_block;
{
ScopedPtrList<Expression> reject_args(pointer_buffer());
reject_args.Add(factory()->NewVariableProxy(
function_state_->scope()->generator_object_var()));
reject_args.Add(factory()->NewVariableProxy(catch_scope->catch_variable()));
Expression* reject_call = factory()->NewCallRuntime(
Runtime::kInlineAsyncGeneratorReject, reject_args, kNoSourcePosition);
catch_block = IgnoreCompletion(
factory()->NewReturnStatement(reject_call, kNoSourcePosition));
}
{
ScopedPtrList<Statement> statements(pointer_buffer());
TryStatement* try_catch = factory()->NewTryCatchStatementForAsyncAwait(
try_block, catch_scope, catch_block, kNoSourcePosition);
statements.Add(try_catch);
try_block = factory()->NewBlock(false, statements);
}
Expression* close_call;
{
ScopedPtrList<Expression> close_args(pointer_buffer());
VariableProxy* call_proxy = factory()->NewVariableProxy(
function_state_->scope()->generator_object_var());
close_args.Add(call_proxy);
close_call = factory()->NewCallRuntime(Runtime::kInlineGeneratorClose,
close_args, kNoSourcePosition);
}
Block* finally_block;
{
ScopedPtrList<Statement> statements(pointer_buffer());
statements.Add(
factory()->NewExpressionStatement(close_call, kNoSourcePosition));
finally_block = factory()->NewBlock(false, statements);
}
body->Add(factory()->NewTryFinallyStatement(try_block, finally_block,
kNoSourcePosition));
}
void Parser::DeclareFunctionNameVar(const AstRawString* function_name,
FunctionLiteral::FunctionType function_type,
DeclarationScope* function_scope) {
if (function_type == FunctionLiteral::kNamedExpression &&
function_scope->LookupLocal(function_name) == nullptr) {
DCHECK_EQ(function_scope, scope());
function_scope->DeclareFunctionVar(function_name);
}
}
// Special case for legacy for
//
// for (var x = initializer in enumerable) body
//
// An initialization block of the form
//
// {
// x = initializer;
// }
//
// is returned in this case. It has reserved space for two statements,
// so that (later on during parsing), the equivalent of
//
// for (x in enumerable) body
//
// is added as a second statement to it.
Block* Parser::RewriteForVarInLegacy(const ForInfo& for_info) {
const DeclarationParsingResult::Declaration& decl =
for_info.parsing_result.declarations[0];
if (!IsLexicalVariableMode(for_info.parsing_result.descriptor.mode) &&
decl.initializer != nullptr && decl.pattern->IsVariableProxy()) {
++use_counts_[v8::Isolate::kForInInitializer];
const AstRawString* name = decl.pattern->AsVariableProxy()->raw_name();
VariableProxy* single_var = NewUnresolved(name);
Block* init_block = factory()->NewBlock(2, true);
init_block->statements()->Add(
factory()->NewExpressionStatement(
factory()->NewAssignment(Token::ASSIGN, single_var,
decl.initializer, decl.value_beg_pos),
kNoSourcePosition),
zone());
return init_block;
}
return nullptr;
}
// Rewrite a for-in/of statement of the form
//
// for (let/const/var x in/of e) b
//
// into
//
// {
// var temp;
// for (temp in/of e) {
// let/const/var x = temp;
// b;
// }
// let x; // for TDZ
// }
void Parser::DesugarBindingInForEachStatement(ForInfo* for_info,
Block** body_block,
Expression** each_variable) {
DCHECK_EQ(1, for_info->parsing_result.declarations.size());
DeclarationParsingResult::Declaration& decl =
for_info->parsing_result.declarations[0];
Variable* temp = NewTemporary(ast_value_factory()->dot_for_string());
ScopedPtrList<Statement> each_initialization_statements(pointer_buffer());
DCHECK_IMPLIES(!has_error(), decl.pattern != nullptr);
decl.initializer = factory()->NewVariableProxy(temp, for_info->position);
InitializeVariables(&each_initialization_statements, NORMAL_VARIABLE, &decl);
*body_block = factory()->NewBlock(3, false);
(*body_block)
->statements()
->Add(factory()->NewBlock(true, each_initialization_statements), zone());
*each_variable = factory()->NewVariableProxy(temp, for_info->position);
}
// Create a TDZ for any lexically-bound names in for in/of statements.
Block* Parser::CreateForEachStatementTDZ(Block* init_block,
const ForInfo& for_info) {
if (IsLexicalVariableMode(for_info.parsing_result.descriptor.mode)) {
DCHECK_NULL(init_block);
init_block = factory()->NewBlock(1, false);
for (int i = 0; i < for_info.bound_names.length(); ++i) {
// TODO(adamk): This needs to be some sort of special
// INTERNAL variable that's invisible to the debugger
// but visible to everything else.
VariableProxy* tdz_proxy = DeclareBoundVariable(
for_info.bound_names[i], VariableMode::kLet, kNoSourcePosition);
tdz_proxy->var()->set_initializer_position(position());
}
}
return init_block;
}
Statement* Parser::DesugarLexicalBindingsInForStatement(
ForStatement* loop, Statement* init, Expression* cond, Statement* next,
Statement* body, Scope* inner_scope, const ForInfo& for_info) {
// ES6 13.7.4.8 specifies that on each loop iteration the let variables are
// copied into a new environment. Moreover, the "next" statement must be
// evaluated not in the environment of the just completed iteration but in
// that of the upcoming one. We achieve this with the following desugaring.
// Extra care is needed to preserve the completion value of the original loop.
//
// We are given a for statement of the form
//
// labels: for (let/const x = i; cond; next) body
//
// and rewrite it as follows. Here we write {{ ... }} for init-blocks, ie.,
// blocks whose ignore_completion_value_ flag is set.
//
// {
// let/const x = i;
// temp_x = x;
// first = 1;
// undefined;
// outer: for (;;) {
// let/const x = temp_x;
// {{ if (first == 1) {
// first = 0;
// } else {
// next;
// }
// flag = 1;
// if (!cond) break;
// }}
// labels: for (; flag == 1; flag = 0, temp_x = x) {
// body
// }
// {{ if (flag == 1) // Body used break.
// break;
// }}
// }
// }
DCHECK_GT(for_info.bound_names.length(), 0);
ZonePtrList<Variable> temps(for_info.bound_names.length(), zone());
Block* outer_block =
factory()->NewBlock(for_info.bound_names.length() + 4, false);
// Add statement: let/const x = i.
outer_block->statements()->Add(init, zone());
const AstRawString* temp_name = ast_value_factory()->dot_for_string();
// For each lexical variable x:
// make statement: temp_x = x.
for (int i = 0; i < for_info.bound_names.length(); i++) {
VariableProxy* proxy = NewUnresolved(for_info.bound_names[i]);
Variable* temp = NewTemporary(temp_name);
VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);
Assignment* assignment = factory()->NewAssignment(Token::ASSIGN, temp_proxy,
proxy, kNoSourcePosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, kNoSourcePosition);
outer_block->statements()->Add(assignment_statement, zone());
temps.Add(temp, zone());
}
Variable* first = nullptr;
// Make statement: first = 1.
if (next) {
first = NewTemporary(temp_name);
VariableProxy* first_proxy = factory()->NewVariableProxy(first);
Expression* const1 = factory()->NewSmiLiteral(1, kNoSourcePosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, first_proxy, const1, kNoSourcePosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, kNoSourcePosition);
outer_block->statements()->Add(assignment_statement, zone());
}
// make statement: undefined;
outer_block->statements()->Add(
factory()->NewExpressionStatement(
factory()->NewUndefinedLiteral(kNoSourcePosition), kNoSourcePosition),
zone());
// Make statement: outer: for (;;)
// Note that we don't actually create the label, or set this loop up as an
// explicit break target, instead handing it directly to those nodes that
// need to know about it. This should be safe because we don't run any code
// in this function that looks up break targets.
ForStatement* outer_loop =
factory()->NewForStatement(nullptr, nullptr, kNoSourcePosition);
outer_block->statements()->Add(outer_loop, zone());
outer_block->set_scope(scope());
Block* inner_block = factory()->NewBlock(3, false);
{
BlockState block_state(&scope_, inner_scope);
Block* ignore_completion_block =
factory()->NewBlock(for_info.bound_names.length() + 3, true);
ZonePtrList<Variable> inner_vars(for_info.bound_names.length(), zone());
// For each let variable x:
// make statement: let/const x = temp_x.
for (int i = 0; i < for_info.bound_names.length(); i++) {
VariableProxy* proxy = DeclareBoundVariable(
for_info.bound_names[i], for_info.parsing_result.descriptor.mode,
kNoSourcePosition);
inner_vars.Add(proxy->var(), zone());
VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i));
Assignment* assignment = factory()->NewAssignment(
Token::INIT, proxy, temp_proxy, kNoSourcePosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, kNoSourcePosition);
int declaration_pos = for_info.parsing_result.descriptor.declaration_pos;
DCHECK_NE(declaration_pos, kNoSourcePosition);
proxy->var()->set_initializer_position(declaration_pos);
ignore_completion_block->statements()->Add(assignment_statement, zone());
}
// Make statement: if (first == 1) { first = 0; } else { next; }
if (next) {
DCHECK(first);
Expression* compare = nullptr;
// Make compare expression: first == 1.
{
Expression* const1 = factory()->NewSmiLiteral(1, kNoSourcePosition);
VariableProxy* first_proxy = factory()->NewVariableProxy(first);
compare = factory()->NewCompareOperation(Token::EQ, first_proxy, const1,
kNoSourcePosition);
}
Statement* clear_first = nullptr;
// Make statement: first = 0.
{
VariableProxy* first_proxy = factory()->NewVariableProxy(first);
Expression* const0 = factory()->NewSmiLiteral(0, kNoSourcePosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, first_proxy, const0, kNoSourcePosition);
clear_first =
factory()->NewExpressionStatement(assignment, kNoSourcePosition);
}
Statement* clear_first_or_next = factory()->NewIfStatement(
compare, clear_first, next, kNoSourcePosition);
ignore_completion_block->statements()->Add(clear_first_or_next, zone());
}
Variable* flag = NewTemporary(temp_name);
// Make statement: flag = 1.
{
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
Expression* const1 = factory()->NewSmiLiteral(1, kNoSourcePosition);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, flag_proxy, const1, kNoSourcePosition);
Statement* assignment_statement =
factory()->NewExpressionStatement(assignment, kNoSourcePosition);
ignore_completion_block->statements()->Add(assignment_statement, zone());
}
// Make statement: if (!cond) break.
if (cond) {
Statement* stop =
factory()->NewBreakStatement(outer_loop, kNoSourcePosition);
Statement* noop = factory()->EmptyStatement();
ignore_completion_block->statements()->Add(
factory()->NewIfStatement(cond, noop, stop, cond->position()),
zone());
}
inner_block->statements()->Add(ignore_completion_block, zone());
// Make cond expression for main loop: flag == 1.
Expression* flag_cond = nullptr;
{
Expression* const1 = factory()->NewSmiLiteral(1, kNoSourcePosition);
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
flag_cond = factory()->NewCompareOperation(Token::EQ, flag_proxy, const1,
kNoSourcePosition);
}
// Create chain of expressions "flag = 0, temp_x = x, ..."
Statement* compound_next_statement = nullptr;
{
Expression* compound_next = nullptr;
// Make expression: flag = 0.
{
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
Expression* const0 = factory()->NewSmiLiteral(0, kNoSourcePosition);
compound_next = factory()->NewAssignment(Token::ASSIGN, flag_proxy,
const0, kNoSourcePosition);
}
// Make the comma-separated list of temp_x = x assignments.
int inner_var_proxy_pos = scanner()->location().beg_pos;
for (int i = 0; i < for_info.bound_names.length(); i++) {
VariableProxy* temp_proxy = factory()->NewVariableProxy(temps.at(i));
VariableProxy* proxy =
factory()->NewVariableProxy(inner_vars.at(i), inner_var_proxy_pos);
Assignment* assignment = factory()->NewAssignment(
Token::ASSIGN, temp_proxy, proxy, kNoSourcePosition);
compound_next = factory()->NewBinaryOperation(
Token::COMMA, compound_next, assignment, kNoSourcePosition);
}
compound_next_statement =
factory()->NewExpressionStatement(compound_next, kNoSourcePosition);
}
// Make statement: labels: for (; flag == 1; flag = 0, temp_x = x)
// Note that we re-use the original loop node, which retains its labels
// and ensures that any break or continue statements in body point to
// the right place.
loop->Initialize(nullptr, flag_cond, compound_next_statement, body);
inner_block->statements()->Add(loop, zone());
// Make statement: {{if (flag == 1) break;}}
{
Expression* compare = nullptr;
// Make compare expresion: flag == 1.
{
Expression* const1 = factory()->NewSmiLiteral(1, kNoSourcePosition);
VariableProxy* flag_proxy = factory()->NewVariableProxy(flag);
compare = factory()->NewCompareOperation(Token::EQ, flag_proxy, const1,
kNoSourcePosition);
}
Statement* stop =
factory()->NewBreakStatement(outer_loop, kNoSourcePosition);
Statement* empty = factory()->EmptyStatement();
Statement* if_flag_break =
factory()->NewIfStatement(compare, stop, empty, kNoSourcePosition);
inner_block->statements()->Add(IgnoreCompletion(if_flag_break), zone());
}
inner_block->set_scope(inner_scope);
}
outer_loop->Initialize(nullptr, nullptr, nullptr, inner_block);
return outer_block;
}
void ParserFormalParameters::ValidateDuplicate(Parser* parser) const {
if (has_duplicate()) {
parser->ReportMessageAt(duplicate_loc, MessageTemplate::kParamDupe);
}
}
void ParserFormalParameters::ValidateStrictMode(Parser* parser) const {
if (strict_error_loc.IsValid()) {
parser->ReportMessageAt(strict_error_loc, strict_error_message);
}
}
void Parser::AddArrowFunctionFormalParameters(
ParserFormalParameters* parameters, Expression* expr, int end_pos) {
// ArrowFunctionFormals ::
// Nary(Token::COMMA, VariableProxy*, Tail)
// Binary(Token::COMMA, NonTailArrowFunctionFormals, Tail)
// Tail
// NonTailArrowFunctionFormals ::
// Binary(Token::COMMA, NonTailArrowFunctionFormals, VariableProxy)
// VariableProxy
// Tail ::
// VariableProxy
// Spread(VariableProxy)
//
// We need to visit the parameters in left-to-right order
//
// For the Nary case, we simply visit the parameters in a loop.
if (expr->IsNaryOperation()) {
NaryOperation* nary = expr->AsNaryOperation();
// The classifier has already run, so we know that the expression is a valid
// arrow function formals production.
DCHECK_EQ(nary->op(), Token::COMMA);
// Each op position is the end position of the *previous* expr, with the
// second (i.e. first "subsequent") op position being the end position of
// the first child expression.
Expression* next = nary->first();
for (size_t i = 0; i < nary->subsequent_length(); ++i) {
AddArrowFunctionFormalParameters(parameters, next,
nary->subsequent_op_position(i));
next = nary->subsequent(i);
}
AddArrowFunctionFormalParameters(parameters, next, end_pos);
return;
}
// For the binary case, we recurse on the left-hand side of binary comma
// expressions.
if (expr->IsBinaryOperation()) {
BinaryOperation* binop = expr->AsBinaryOperation();
// The classifier has already run, so we know that the expression is a valid
// arrow function formals production.
DCHECK_EQ(binop->op(), Token::COMMA);
Expression* left = binop->left();
Expression* right = binop->right();
int comma_pos = binop->position();
AddArrowFunctionFormalParameters(parameters, left, comma_pos);
// LHS of comma expression should be unparenthesized.
expr = right;
}
// Only the right-most expression may be a rest parameter.
DCHECK(!parameters->has_rest);
bool is_rest = expr->IsSpread();
if (is_rest) {
expr = expr->AsSpread()->expression();
parameters->has_rest = true;
}
DCHECK_IMPLIES(parameters->is_simple, !is_rest);
DCHECK_IMPLIES(parameters->is_simple, expr->IsVariableProxy());
Expression* initializer = nullptr;
if (expr->IsAssignment()) {
Assignment* assignment = expr->AsAssignment();
DCHECK(!assignment->IsCompoundAssignment());
initializer = assignment->value();
expr = assignment->target();
}
AddFormalParameter(parameters, expr, initializer, end_pos, is_rest);
}
void Parser::DeclareArrowFunctionFormalParameters(
ParserFormalParameters* parameters, Expression* expr,
const Scanner::Location& params_loc) {
if (expr->IsEmptyParentheses() || has_error()) return;
AddArrowFunctionFormalParameters(parameters, expr, params_loc.end_pos);
if (parameters->arity > Code::kMaxArguments) {
ReportMessageAt(params_loc, MessageTemplate::kMalformedArrowFunParamList);
return;
}
DeclareFormalParameters(parameters);
DCHECK_IMPLIES(parameters->is_simple,
parameters->scope->has_simple_parameters());
}
void Parser::PrepareGeneratorVariables() {
// Calling a generator returns a generator object. That object is stored
// in a temporary variable, a definition that is used by "yield"
// expressions.
function_state_->scope()->DeclareGeneratorObjectVar(
ast_value_factory()->dot_generator_object_string());
}
FunctionLiteral* Parser::ParseFunctionLiteral(
const AstRawString* function_name, Scanner::Location function_name_location,
FunctionNameValidity function_name_validity, FunctionKind kind,
int function_token_pos, FunctionLiteral::FunctionType function_type,
LanguageMode language_mode,
ZonePtrList<const AstRawString>* arguments_for_wrapped_function) {
// Function ::
// '(' FormalParameterList? ')' '{' FunctionBody '}'
//
// Getter ::
// '(' ')' '{' FunctionBody '}'
//
// Setter ::
// '(' PropertySetParameterList ')' '{' FunctionBody '}'
bool is_wrapped = function_type == FunctionLiteral::kWrapped;
DCHECK_EQ(is_wrapped, arguments_for_wrapped_function != nullptr);
int pos = function_token_pos == kNoSourcePosition ? peek_position()
: function_token_pos;
DCHECK_NE(kNoSourcePosition, pos);
// 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 == nullptr;
// We want a non-null handle as the function name by default. We will handle
// the "function does not have a shared name" case later.
if (should_infer_name) {
function_name = ast_value_factory()->empty_string();
}
FunctionLiteral::EagerCompileHint eager_compile_hint =
function_state_->next_function_is_likely_called() || is_wrapped
? FunctionLiteral::kShouldEagerCompile
: default_eager_compile_hint();
// 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.
// We separate between lazy parsing top level functions and lazy parsing inner
// functions, because the latter needs to do more work. In particular, we need
// to track unresolved variables 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). bar can be parsed lazily, but we need to parse it in a mode
// that tracks unresolved variables.
DCHECK_IMPLIES(parse_lazily(), info()->allow_lazy_compile());
DCHECK_IMPLIES(parse_lazily(), has_error() || allow_lazy_);
DCHECK_IMPLIES(parse_lazily(), extension_ == nullptr);
const bool is_lazy =
eager_compile_hint == FunctionLiteral::kShouldLazyCompile;
const bool is_top_level = AllowsLazyParsingWithoutUnresolvedVariables();
const bool is_eager_top_level_function = !is_lazy && is_top_level;
const bool is_lazy_top_level_function = is_lazy && is_top_level;
const bool is_lazy_inner_function = is_lazy && !is_top_level;
RuntimeCallTimerScope runtime_timer(
runtime_call_stats_,
parsing_on_main_thread_
? RuntimeCallCounterId::kParseFunctionLiteral
: RuntimeCallCounterId::kParseBackgroundFunctionLiteral);
base::ElapsedTimer timer;
if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
// Determine whether we can still lazy parse the inner function.
// The preconditions are:
// - Lazy compilation has to be enabled.
// - Neither V8 natives nor native function declarations can be allowed,
// since parsing one would retroactively force the function to be
// eagerly compiled.
// - The invoker of this parser can't depend on the AST being eagerly
// built (either because the function is about to be compiled, or
// because the AST is going to be inspected for some reason).
// - Because of the above, we can't be attempting to parse a
// FunctionExpression; even without enclosing parentheses it might be
// immediately invoked.
// - The function literal shouldn't be hinted to eagerly compile.
// Inner functions will be parsed using a temporary Zone. After parsing, we
// will migrate unresolved variable into a Scope in the main Zone.
const bool should_preparse_inner = parse_lazily() && is_lazy_inner_function;
// If parallel compile tasks are enabled, and the function is an eager
// top level function, then we can pre-parse the function and parse / compile
// in a parallel task on a worker thread.
bool should_post_parallel_task =
parse_lazily() && is_eager_top_level_function &&
FLAG_parallel_compile_tasks && info()->parallel_tasks() &&
scanner()->stream()->can_be_cloned_for_parallel_access();
// This may be modified later to reflect preparsing decision taken
bool should_preparse = (parse_lazily() && is_lazy_top_level_function) ||
should_preparse_inner || should_post_parallel_task;
ScopedPtrList<Statement> body(pointer_buffer());
int expected_property_count = -1;
int suspend_count = -1;
int num_parameters = -1;
int function_length = -1;
bool has_duplicate_parameters = false;
int function_literal_id = GetNextFunctionLiteralId();
ProducedPreparseData* produced_preparse_data = nullptr;
// This Scope lives in the main zone. We'll migrate data into that zone later.
Zone* parse_zone = should_preparse ? &preparser_zone_ : zone();
DeclarationScope* scope = NewFunctionScope(kind, parse_zone);
SetLanguageMode(scope, language_mode);
#ifdef DEBUG
scope->SetScopeName(function_name);
#endif
if (!is_wrapped && V8_UNLIKELY(!Check(Token::LPAREN))) {
ReportUnexpectedToken(Next());
return nullptr;
}
scope->set_start_position(position());
// Eager or lazy parse? If is_lazy_top_level_function, we'll parse
// lazily. We'll call SkipFunction, which may decide to
// abort lazy parsing if it suspects that wasn't a good idea. If so (in
// which case the parser is expected to have backtracked), or if we didn't
// try to lazy parse in the first place, we'll have to parse eagerly.
bool did_preparse_successfully =
should_preparse && SkipFunction(function_name, kind, function_type, scope,
&num_parameters, &produced_preparse_data);
if (!did_preparse_successfully) {
// If skipping aborted, it rewound the scanner until before the LPAREN.
// Consume it in that case.
if (should_preparse) Consume(Token::LPAREN);
should_post_parallel_task = false;
ParseFunction(&body, function_name, pos, kind, function_type, scope,
&num_parameters, &function_length, &has_duplicate_parameters,
&expected_property_count, &suspend_count,
arguments_for_wrapped_function);
}
if (V8_UNLIKELY(FLAG_log_function_events)) {
double ms = timer.Elapsed().InMillisecondsF();
const char* event_name =
should_preparse
? (is_top_level ? "preparse-no-resolution" : "preparse-resolution")
: "full-parse";
logger_->FunctionEvent(
event_name, script_id(), ms, scope->start_position(),
scope->end_position(),
reinterpret_cast<const char*>(function_name->raw_data()),
function_name->byte_length());
}
if (V8_UNLIKELY(FLAG_runtime_stats) && did_preparse_successfully) {
const RuntimeCallCounterId counters[2] = {
RuntimeCallCounterId::kPreParseBackgroundWithVariableResolution,
RuntimeCallCounterId::kPreParseWithVariableResolution};
if (runtime_call_stats_) {
runtime_call_stats_->CorrectCurrentCounterId(
counters[parsing_on_main_thread_]);
}
}
// Validate function name. We can do this only after parsing the function,
// since the function can declare itself strict.
language_mode = scope->language_mode();
CheckFunctionName(language_mode, function_name, function_name_validity,
function_name_location);
if (is_strict(language_mode)) {
CheckStrictOctalLiteral(scope->start_position(), scope->end_position());
}
FunctionLiteral::ParameterFlag duplicate_parameters =
has_duplicate_parameters ? FunctionLiteral::kHasDuplicateParameters
: FunctionLiteral::kNoDuplicateParameters;
// Note that the FunctionLiteral needs to be created in the main Zone again.
FunctionLiteral* function_literal = factory()->NewFunctionLiteral(
function_name, scope, body, expected_property_count, num_parameters,
function_length, duplicate_parameters, function_type, eager_compile_hint,
pos, true, function_literal_id, produced_preparse_data);
function_literal->set_function_token_position(function_token_pos);
function_literal->set_suspend_count(suspend_count);
if (should_post_parallel_task) {
// Start a parallel parse / compile task on the compiler dispatcher.
info()->parallel_tasks()->Enqueue(info(), function_name, function_literal);
}
if (should_infer_name) {
fni_.AddFunction(function_literal);
}
return function_literal;
}
bool Parser::SkipFunction(const AstRawString* function_name, FunctionKind kind,
FunctionLiteral::FunctionType function_type,
DeclarationScope* function_scope, int* num_parameters,
ProducedPreparseData** produced_preparse_data) {
FunctionState function_state(&function_state_, &scope_, function_scope);
function_scope->set_zone(&preparser_zone_);
DCHECK_NE(kNoSourcePosition, function_scope->start_position());
DCHECK_EQ(kNoSourcePosition, parameters_end_pos_);
DCHECK_IMPLIES(IsArrowFunction(kind),
scanner()->current_token() == Token::ARROW);
// FIXME(marja): There are 2 ways to skip functions now. Unify them.
if (consumed_preparse_data_) {
int end_position;
LanguageMode language_mode;
int num_inner_functions;
bool uses_super_property;
if (stack_overflow()) return true;
*produced_preparse_data =
consumed_preparse_data_->GetDataForSkippableFunction(
main_zone(), function_scope->start_position(), &end_position,
num_parameters, &num_inner_functions, &uses_super_property,
&language_mode);
function_scope->outer_scope()->SetMustUsePreparseData();
function_scope->set_is_skipped_function(true);
function_scope->set_end_position(end_position);
scanner()->SeekForward(end_position - 1);
Expect(Token::RBRACE);
SetLanguageMode(function_scope, language_mode);
if (uses_super_property) {
function_scope->RecordSuperPropertyUsage();
}
SkipFunctionLiterals(num_inner_functions);
function_scope->ResetAfterPreparsing(ast_value_factory_, false);
return true;
}
Scanner::BookmarkScope bookmark(scanner());
bookmark.Set(function_scope->start_position());
// With no cached data, we partially parse the function, without building an
// AST. This gathers the data needed to build a lazy function.
TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.PreParse");
PreParser::PreParseResult result = reusable_preparser()->PreParseFunction(
function_name, kind, function_type, function_scope, use_counts_,
produced_preparse_data, this->script_id());
if (result == PreParser::kPreParseStackOverflow) {
// Propagate stack overflow.
set_stack_overflow();
} else if (pending_error_handler()->has_error_unidentifiable_by_preparser()) {
// Make sure we don't re-preparse inner functions of the aborted function.
// The error might be in an inner function.
allow_lazy_ = false;
mode_ = PARSE_EAGERLY;
DCHECK(!pending_error_handler()->stack_overflow());
// If we encounter an error that the preparser can not identify we reset to
// the state before preparsing. The caller may then fully parse the function
// to identify the actual error.
bookmark.Apply();
function_scope->ResetAfterPreparsing(ast_value_factory(), true);
pending_error_handler()->clear_unidentifiable_error();
return false;
} else if (pending_error_handler()->has_pending_error()) {
DCHECK(!pending_error_handler()->stack_overflow());
DCHECK(has_error());
} else {
DCHECK(!pending_error_handler()->stack_overflow());
set_allow_eval_cache(reusable_preparser()->allow_eval_cache());
PreParserLogger* logger = reusable_preparser()->logger();
function_scope->set_end_position(logger->end());
Expect(Token::RBRACE);
total_preparse_skipped_ +=
function_scope->end_position() - function_scope->start_position();
*num_parameters = logger->num_parameters();
SkipFunctionLiterals(logger->num_inner_functions());
function_scope->AnalyzePartially(this, factory());
}
return true;
}
Block* Parser::BuildParameterInitializationBlock(
const ParserFormalParameters& parameters) {
DCHECK(!parameters.is_simple);
DCHECK(scope()->is_function_scope());
DCHECK_EQ(scope(), parameters.scope);
ScopedPtrList<Statement> init_statements(pointer_buffer());
int index = 0;
for (auto parameter : parameters.params) {
Expression* initial_value =
factory()->NewVariableProxy(parameters.scope->parameter(index));
if (parameter->initializer() != nullptr) {
// IS_UNDEFINED($param) ? initializer : $param
auto condition = factory()->NewCompareOperation(
Token::EQ_STRICT,
factory()->NewVariableProxy(parameters.scope->parameter(index)),
factory()->NewUndefinedLiteral(kNoSourcePosition), kNoSourcePosition);