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parser.cc
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// 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/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/messages.h"
#include "src/objects/scope-info.h"
#include "src/parsing/duplicate-finder.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);
ZonePtrList<Statement>* body = nullptr;
{
FunctionState function_state(&function_state_, &scope_, function_scope);
body = new (zone()) ZonePtrList<Statement>(call_super ? 2 : 1, zone());
if (call_super) {
// Create a SuperCallReference and handle in BytecodeGenerator.
auto constructor_args_name = ast_value_factory()->empty_string();
bool is_duplicate;
bool is_rest = true;
bool is_optional = false;
Variable* constructor_args = function_scope->DeclareParameter(
constructor_args_name, VariableMode::kTemporary, is_optional, is_rest,
&is_duplicate, ast_value_factory(), pos);
ZonePtrList<Expression>* args =
new (zone()) ZonePtrList<Expression>(1, zone());
Spread* spread_args = factory()->NewSpread(
factory()->NewVariableProxy(constructor_args), pos, pos);
args->Add(spread_args, zone());
Expression* super_call_ref = NewSuperCallReference(pos);
Expression* call = factory()->NewCall(super_call_ref, args, pos);
body->Add(factory()->NewReturnStatement(call, pos), zone());
}
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;
}
// ----------------------------------------------------------------------------
// 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_VALUE(x) ok); \
if (!*ok) return x; \
((void)0
#define DUMMY ) // to make indentation work
#undef DUMMY
#define CHECK_OK CHECK_OK_VALUE(nullptr)
#define CHECK_OK_VOID CHECK_OK_VALUE(this->Void())
#define CHECK_FAILED /**/); \
if (failed_) return nullptr; \
((void)0
#define DUMMY ) // to make indentation work
#undef DUMMY
// ----------------------------------------------------------------------------
// 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(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;
}
case Token::EXP: {
double value = Pow(x_val, y_val);
int int_value = static_cast<int>(value);
*x = factory()->NewNumberLiteral(
int_value == value && value != -0.0 ? int_value : value, pos);
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);
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::Template message,
const AstRawString* arg, int pos) {
ZonePtrList<Expression>* args =
new (zone()) ZonePtrList<Expression>(2, zone());
args->Add(factory()->NewSmiLiteral(message, pos), zone());
args->Add(factory()->NewStringLiteral(arg, pos), zone());
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) {
return factory()->NewCallRuntime(
Runtime::kInlineGetImportMetaObject,
new (zone()) ZonePtrList<Expression>(0, zone()), pos);
}
Literal* 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);
default:
DCHECK(false);
}
return nullptr;
}
Expression* Parser::NewV8Intrinsic(const AstRawString* name,
ZonePtrList<Expression>* args, int pos,
bool* ok) {
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 for built-in IS_VAR macro.
if (function->function_id == Runtime::kIS_VAR) {
DCHECK_EQ(Runtime::RUNTIME, function->intrinsic_type);
// %IS_VAR(x) evaluates to x if x is a variable,
// leads to a parse error otherwise. Could be implemented as an
// inline function %_IS_VAR(x) to eliminate this special case.
if (args->length() == 1 && args->at(0)->AsVariableProxy() != nullptr) {
return args->at(0);
} else {
ReportMessage(MessageTemplate::kNotIsvar);
*ok = false;
return nullptr;
}
}
// Check that the expected number of arguments are being passed.
if (function->nargs != -1 && function->nargs != args->length()) {
ReportMessage(MessageTemplate::kRuntimeWrongNumArgs);
*ok = false;
return nullptr;
}
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);
*ok = false;
return nullptr;
}
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),
scanner_(info->unicode_cache(), 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_preparsed_scope_data_(info->consumed_preparsed_scope_data()),
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 = FLAG_lazy && !info->is_eager();
set_default_eager_compile_hint(can_compile_lazily
? FunctionLiteral::kShouldLazyCompile
: FunctionLiteral::kShouldEagerCompile);
allow_lazy_ = FLAG_lazy && info->allow_lazy_parsing() && !info->is_native() &&
info->extension() == nullptr && can_compile_lazily;
set_allow_natives(FLAG_allow_natives_syntax || info->is_native());
set_allow_harmony_do_expressions(FLAG_harmony_do_expressions);
set_allow_harmony_public_fields(FLAG_harmony_public_fields);
set_allow_harmony_static_fields(FLAG_harmony_static_fields);
set_allow_harmony_dynamic_import(FLAG_harmony_dynamic_import);
set_allow_harmony_import_meta(FLAG_harmony_import_meta);
set_allow_harmony_numeric_separator(FLAG_harmony_numeric_separator);
set_allow_harmony_private_fields(FLAG_harmony_private_fields);
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());
// TODO(wingo): Add an outer SCRIPT_SCOPE corresponding to the native
// context, which will have the "this" binding for script scopes.
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) {
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(), Scope::DeserializationMode::kScopesOnly);
}
}
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 (!FLAG_stress_validate_asm &&
(literal == nullptr || !literal->scope()->ContainsAsmModule())) {
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());
scanner_.Initialize();
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);
ZonePtrList<Statement>* body =
new (zone()) ZonePtrList<Statement>(16, zone());
bool ok = true;
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_duplicate = false;
bool is_rest = false;
bool is_optional = false;
auto var = scope->DeclareParameter(name, VariableMode::kVar, is_optional,
is_rest, &is_duplicate,
ast_value_factory(), beg_pos);
DCHECK(!is_duplicate);
var->AllocateTo(VariableLocation::PARAMETER, 0);
PrepareGeneratorVariables();
Expression* initial_yield =
BuildInitialYield(kNoSourcePosition, kGeneratorFunction);
body->Add(
factory()->NewExpressionStatement(initial_yield, kNoSourcePosition),
zone());
ParseModuleItemList(body, &ok);
ok = ok && module()->Validate(this->scope()->AsModuleScope(),
pending_error_handler(), zone());
} else if (info->is_wrapped_as_function()) {
ParseWrapped(isolate, info, body, scope, zone(), &ok);
} 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, &ok);
}
// The parser will peek but not consume EOS. Our scope logically goes all
// the way to the EOS, though.
scope->set_end_position(scanner()->peek_location().beg_pos);
if (ok && is_strict(language_mode())) {
CheckStrictOctalLiteral(beg_pos, scanner()->location().end_pos, &ok);
}
if (ok && is_sloppy(language_mode())) {
// TODO(littledan): Function bindings on the global object that modify
// pre-existing bindings should be made writable, enumerable and
// nonconfigurable if possible, whereas this code will leave attributes
// unchanged if the property already exists.
InsertSloppyBlockFunctionVarBindings(scope);
}
if (ok) {
CheckConflictingVarDeclarations(scope, &ok);
}
if (ok && info->parse_restriction() == ONLY_SINGLE_FUNCTION_LITERAL) {
if (body->length() != 1 ||
!body->at(0)->IsExpressionStatement() ||
!body->at(0)->AsExpressionStatement()->
expression()->IsFunctionLiteral()) {
ReportMessage(MessageTemplate::kSingleFunctionLiteral);
ok = false;
}
}
if (ok) {
RewriteDestructuringAssignments();
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_);
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,
ZonePtrList<Statement>* body,
DeclarationScope* outer_scope, Zone* zone, bool* ok) {
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, CHECK_OK_VOID);
Statement* return_statement = factory()->NewReturnStatement(
function_literal, kNoSourcePosition, kNoSourcePosition);
body->Add(return_statement, zone);
}
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());
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();
bool ok = true;
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);
// 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());
ExpressionClassifier formals_classifier(this);
ParserFormalParameters formals(scope);
// The outer FunctionState should not contain destructuring assignments.
DCHECK_EQ(0,
function_state.destructuring_assignments_to_rewrite().size());
{
// 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, &ok);
if (ok) ok = Check(Token::RPAREN);
} else {
// BindingIdentifier
ParseFormalParameter(&formals, &ok);
if (ok) {
DeclareFormalParameters(formals.scope, formals.params,
formals.is_simple);
}
}
}
if (ok) {
if (GetLastFunctionLiteralId() != info->function_literal_id() - 1) {
// 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);
}
// Pass `accept_IN=true` to ParseArrowFunctionLiteral --- This should
// not be observable, or else the preparser would have failed.
const bool accept_IN = true;
// Any destructuring assignments in the current FunctionState
// actually belong to the arrow function itself.
const int rewritable_length = 0;
Expression* expression = ParseArrowFunctionLiteral(
accept_IN, formals, rewritable_length, &ok);
if (ok) {
// Scanning must end at the same position that was recorded
// previously. If not, parsing has been interrupted due to a stack
// overflow, at which point the partially parsed arrow function
// concise body happens to be a valid expression. This is a problem
// only for arrow functions with single expression bodies, since there
// is no end token such as "}" for normal functions.
if (scanner()->location().end_pos == info->end_position()) {
// The pre-parser saw an arrow function here, so the full parser
// must produce a FunctionLiteral.
DCHECK(expression->IsFunctionLiteral());
result = expression->AsFunctionLiteral();
} else {
ok = false;
}
}
}
} else if (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, &ok);
}
if (ok) {
result->set_requires_instance_fields_initializer(
info->requires_instance_fields_initializer());
}
// Make sure the results agree.
DCHECK(ok == (result != nullptr));
}
// 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(bool* ok) {
// ecma262/#prod-ModuleItem
// ModuleItem :
// ImportDeclaration
// ExportDeclaration
// StatementListItem
Token::Value next = peek();
if (next == Token::EXPORT) {
return ParseExportDeclaration(ok);
}
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(CHECK_OK);
return factory()->NewEmptyStatement(kNoSourcePosition);
}
}
return ParseStatementListItem(ok);
}
void Parser::ParseModuleItemList(ZonePtrList<Statement>* body, bool* ok) {
// ecma262/#prod-Module
// Module :
// ModuleBody?
//
// ecma262/#prod-ModuleItemList
// ModuleBody :
// ModuleItem*
DCHECK(scope()->is_module_scope());
while (peek() != Token::EOS) {
Statement* stat = ParseModuleItem(CHECK_OK_VOID);
if (stat && !stat->IsEmpty()) {
body->Add(stat, zone());
}
}
}
const AstRawString* Parser::ParseModuleSpecifier(bool* ok) {
// ModuleSpecifier :
// StringLiteral
Expect(Token::STRING, CHECK_OK);
return GetSymbol();
}
ZoneChunkList<Parser::ExportClauseData>* Parser::ParseExportClause(
Scanner::Location* reserved_loc, bool* ok) {
// ExportClause :
// '{' '}'
// '{' ExportsList '}'
// '{' ExportsList ',' '}'
//
// ExportsList :
// ExportSpecifier
// ExportsList ',' ExportSpecifier
//
// ExportSpecifier :
// IdentifierName
// IdentifierName 'as' IdentifierName
ZoneChunkList<ExportClauseData>* export_data =
new (zone()) ZoneChunkList<ExportClauseData>(zone());
Expect(Token::LBRACE, CHECK_OK);
Token::Value name_tok;
while ((name_tok = peek()) != Token::RBRACE) {
// Keep track of the first reserved word encountered in case our
// caller needs to report an error.
if (!reserved_loc->IsValid() &&
!Token::IsIdentifier(name_tok, LanguageMode::kStrict, false,
parsing_module_)) {
*reserved_loc = scanner()->location();
}
const AstRawString* local_name = ParseIdentifierName(CHECK_OK);
const AstRawString* export_name = nullptr;
Scanner::Location location = scanner()->location();
if (CheckContextualKeyword(Token::AS)) {
export_name = ParseIdentifierName(CHECK_OK);
// 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;
Expect(Token::COMMA, CHECK_OK);
}
Expect(Token::RBRACE, CHECK_OK);
return export_data;
}
ZonePtrList<const Parser::NamedImport>* Parser::ParseNamedImports(int pos,
bool* ok) {
// NamedImports :
// '{' '}'
// '{' ImportsList '}'
// '{' ImportsList ',' '}'
//
// ImportsList :
// ImportSpecifier
// ImportsList ',' ImportSpecifier
//
// ImportSpecifier :
// BindingIdentifier
// IdentifierName 'as' BindingIdentifier
Expect(Token::LBRACE, CHECK_OK);
auto result = new (zone()) ZonePtrList<const NamedImport>(1, zone());
while (peek() != Token::RBRACE) {
const AstRawString* import_name = ParseIdentifierName(CHECK_OK);
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(Token::AS)) {
local_name = ParseIdentifierName(CHECK_OK);
}
if (!Token::IsIdentifier(scanner()->current_token(), LanguageMode::kStrict,
false, parsing_module_)) {
*ok = false;
ReportMessage(MessageTemplate::kUnexpectedReserved);
return nullptr;
} else if (IsEvalOrArguments(local_name)) {
*ok = false;
ReportMessage(MessageTemplate::kStrictEvalArguments);
return nullptr;
}
DeclareVariable(local_name, VariableMode::kConst, kNeedsInitialization,
position(), CHECK_OK);