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cobalt / cobalt / d2bc3b69d823bbaf46d1c4355b23486a85a6d791 / . / third_party / v8 / src / parsing / parser-base.h
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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.
#ifndef V8_PARSING_PARSER_BASE_H_
#define V8_PARSING_PARSER_BASE_H_
#include <stdint.h>
#include <utility>
#include <vector>
#include "src/ast/ast-source-ranges.h"
#include "src/ast/ast.h"
#include "src/ast/scopes.h"
#include "src/base/flags.h"
#include "src/base/hashmap.h"
#include "src/base/v8-fallthrough.h"
#include "src/codegen/bailout-reason.h"
#include "src/common/globals.h"
#include "src/common/message-template.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/objects/function-kind.h"
#include "src/parsing/expression-scope.h"
#include "src/parsing/func-name-inferrer.h"
#include "src/parsing/parse-info.h"
#include "src/parsing/scanner.h"
#include "src/parsing/token.h"
#include "src/utils/pointer-with-payload.h"
#include "src/zone/zone-chunk-list.h"
namespace v8 {
namespace internal {
enum FunctionNameValidity {
kFunctionNameIsStrictReserved,
kSkipFunctionNameCheck,
kFunctionNameValidityUnknown
};
enum AllowLabelledFunctionStatement {
kAllowLabelledFunctionStatement,
kDisallowLabelledFunctionStatement,
};
enum ParsingArrowHeadFlag { kCertainlyNotArrowHead, kMaybeArrowHead };
enum class ParseFunctionFlag : uint8_t {
kIsNormal = 0,
kIsGenerator = 1 << 0,
kIsAsync = 1 << 1
};
using ParseFunctionFlags = base::Flags<ParseFunctionFlag>;
struct FormalParametersBase {
explicit FormalParametersBase(DeclarationScope* scope) : scope(scope) {}
int num_parameters() const {
// Don't include the rest parameter into the function's formal parameter
// count (esp. the SharedFunctionInfo::internal_formal_parameter_count,
// which says whether we need to create an arguments adaptor frame).
return arity - has_rest;
}
void UpdateArityAndFunctionLength(bool is_optional, bool is_rest) {
if (!is_optional && !is_rest && function_length == arity) {
++function_length;
}
++arity;
}
DeclarationScope* scope;
bool has_rest = false;
bool is_simple = true;
int function_length = 0;
int arity = 0;
};
// Stack-allocated scope to collect source ranges from the parser.
class SourceRangeScope final {
public:
SourceRangeScope(const Scanner* scanner, SourceRange* range)
: scanner_(scanner), range_(range) {
range_->start = scanner->peek_location().beg_pos;
DCHECK_NE(range_->start, kNoSourcePosition);
DCHECK_EQ(range_->end, kNoSourcePosition);
}
~SourceRangeScope() {
DCHECK_EQ(kNoSourcePosition, range_->end);
range_->end = scanner_->location().end_pos;
DCHECK_NE(range_->end, kNoSourcePosition);
}
private:
const Scanner* scanner_;
SourceRange* range_;
DISALLOW_IMPLICIT_CONSTRUCTORS(SourceRangeScope);
};
// ----------------------------------------------------------------------------
// The RETURN_IF_PARSE_ERROR macro is a convenient macro to enforce error
// handling for functions that may fail (by returning if there was an parser
// error).
//
// Usage:
// foo = ParseFoo(); // may fail
// RETURN_IF_PARSE_ERROR
//
// SAFE_USE(foo);
#define RETURN_IF_PARSE_ERROR \
if (has_error()) return impl()->NullStatement();
// Common base class template shared between parser and pre-parser.
// The Impl parameter is the actual class of the parser/pre-parser,
// following the Curiously Recurring Template Pattern (CRTP).
// The structure of the parser objects is roughly the following:
//
// // A structure template containing type definitions, needed to
// // avoid a cyclic dependency.
// template <typename Impl>
// struct ParserTypes;
//
// // The parser base object, which should just implement pure
// // parser behavior. The Impl parameter is the actual derived
// // class (according to CRTP), which implements impure parser
// // behavior.
// template <typename Impl>
// class ParserBase { ... };
//
// // And then, for each parser variant (e.g., parser, preparser, etc):
// class Parser;
//
// template <>
// class ParserTypes<Parser> { ... };
//
// class Parser : public ParserBase<Parser> { ... };
//
// The parser base object implements pure parsing, according to the
// language grammar. Different parser implementations may exhibit
// different parser-driven behavior that is not considered as pure
// parsing, e.g., early error detection and reporting, AST generation, etc.
// The ParserTypes structure encapsulates the differences in the
// types used in parsing methods. E.g., Parser methods use Expression*
// and PreParser methods use PreParserExpression. For any given parser
// implementation class Impl, it is expected to contain the following typedefs:
//
// template <>
// struct ParserTypes<Impl> {
// // Synonyms for ParserBase<Impl> and Impl, respectively.
// typedef Base;
// typedef Impl;
// // Return types for traversing functions.
// typedef Identifier;
// typedef Expression;
// typedef FunctionLiteral;
// typedef ObjectLiteralProperty;
// typedef ClassLiteralProperty;
// typedef ExpressionList;
// typedef ObjectPropertyList;
// typedef ClassPropertyList;
// typedef FormalParameters;
// typedef Statement;
// typedef StatementList;
// typedef Block;
// typedef BreakableStatement;
// typedef ForStatement;
// typedef IterationStatement;
// // For constructing objects returned by the traversing functions.
// typedef Factory;
// // For other implementation-specific tasks.
// typedef Target;
// typedef TargetScope;
// };
template <typename Impl>
struct ParserTypes;
enum class ParsePropertyKind : uint8_t {
kAccessorGetter,
kAccessorSetter,
kValue,
kShorthand,
kAssign,
kMethod,
kClassField,
kShorthandOrClassField,
kSpread,
kNotSet
};
template <typename Impl>
class ParserBase {
public:
// Shorten type names defined by ParserTypes<Impl>.
using Types = ParserTypes<Impl>;
using ExpressionScope = typename v8::internal::ExpressionScope<Types>;
using ExpressionParsingScope =
typename v8::internal::ExpressionParsingScope<Types>;
using AccumulationScope = typename v8::internal::AccumulationScope<Types>;
using ArrowHeadParsingScope =
typename v8::internal::ArrowHeadParsingScope<Types>;
using VariableDeclarationParsingScope =
typename v8::internal::VariableDeclarationParsingScope<Types>;
using ParameterDeclarationParsingScope =
typename v8::internal::ParameterDeclarationParsingScope<Types>;
// Return types for traversing functions.
using BlockT = typename Types::Block;
using BreakableStatementT = typename Types::BreakableStatement;
using ClassLiteralPropertyT = typename Types::ClassLiteralProperty;
using ClassPropertyListT = typename Types::ClassPropertyList;
using ExpressionT = typename Types::Expression;
using ExpressionListT = typename Types::ExpressionList;
using FormalParametersT = typename Types::FormalParameters;
using ForStatementT = typename Types::ForStatement;
using FunctionLiteralT = typename Types::FunctionLiteral;
using IdentifierT = typename Types::Identifier;
using IterationStatementT = typename Types::IterationStatement;
using ObjectLiteralPropertyT = typename Types::ObjectLiteralProperty;
using ObjectPropertyListT = typename Types::ObjectPropertyList;
using StatementT = typename Types::Statement;
using StatementListT = typename Types::StatementList;
using SuspendExpressionT = typename Types::Suspend;
// For constructing objects returned by the traversing functions.
using FactoryT = typename Types::Factory;
// Other implementation-specific tasks.
using FuncNameInferrer = typename Types::FuncNameInferrer;
using FuncNameInferrerState = typename Types::FuncNameInferrer::State;
using SourceRange = typename Types::SourceRange;
using SourceRangeScope = typename Types::SourceRangeScope;
// All implementation-specific methods must be called through this.
Impl* impl() { return static_cast<Impl*>(this); }
const Impl* impl() const { return static_cast<const Impl*>(this); }
ParserBase(Zone* zone, Scanner* scanner, uintptr_t stack_limit,
v8::Extension* extension, AstValueFactory* ast_value_factory,
PendingCompilationErrorHandler* pending_error_handler,
RuntimeCallStats* runtime_call_stats, Logger* logger,
UnoptimizedCompileFlags flags, bool parsing_on_main_thread)
: scope_(nullptr),
original_scope_(nullptr),
function_state_(nullptr),
extension_(extension),
fni_(ast_value_factory),
ast_value_factory_(ast_value_factory),
ast_node_factory_(ast_value_factory, zone),
runtime_call_stats_(runtime_call_stats),
logger_(logger),
parsing_on_main_thread_(parsing_on_main_thread),
stack_limit_(stack_limit),
pending_error_handler_(pending_error_handler),
zone_(zone),
expression_scope_(nullptr),
scanner_(scanner),
flags_(flags),
function_literal_id_(0),
default_eager_compile_hint_(FunctionLiteral::kShouldLazyCompile) {
pointer_buffer_.reserve(32);
variable_buffer_.reserve(32);
}
const UnoptimizedCompileFlags& flags() const { return flags_; }
bool allow_eval_cache() const { return allow_eval_cache_; }
void set_allow_eval_cache(bool allow) { allow_eval_cache_ = allow; }
V8_INLINE bool has_error() const { return scanner()->has_parser_error(); }
uintptr_t stack_limit() const { return stack_limit_; }
void set_stack_limit(uintptr_t stack_limit) { stack_limit_ = stack_limit; }
void set_default_eager_compile_hint(
FunctionLiteral::EagerCompileHint eager_compile_hint) {
default_eager_compile_hint_ = eager_compile_hint;
}
FunctionLiteral::EagerCompileHint default_eager_compile_hint() const {
return default_eager_compile_hint_;
}
int loop_nesting_depth() const {
return function_state_->loop_nesting_depth();
}
int GetNextFunctionLiteralId() { return ++function_literal_id_; }
int GetLastFunctionLiteralId() const { return function_literal_id_; }
void SkipFunctionLiterals(int delta) { function_literal_id_ += delta; }
void ResetFunctionLiteralId() { function_literal_id_ = 0; }
// The Zone where the parsing outputs are stored.
Zone* main_zone() const { return ast_value_factory()->zone(); }
// The current Zone, which might be the main zone or a temporary Zone.
Zone* zone() const { return zone_; }
protected:
friend class v8::internal::ExpressionScope<ParserTypes<Impl>>;
friend class v8::internal::ExpressionParsingScope<ParserTypes<Impl>>;
friend class v8::internal::ArrowHeadParsingScope<ParserTypes<Impl>>;
enum VariableDeclarationContext {
kStatementListItem,
kStatement,
kForStatement
};
class ClassLiteralChecker;
// ---------------------------------------------------------------------------
// BlockState and FunctionState implement the parser's scope stack.
// The parser's current scope is in scope_. BlockState and FunctionState
// constructors push on the scope stack and the destructors pop. They are also
// used to hold the parser's per-funcion state.
class BlockState {
public:
BlockState(Scope** scope_stack, Scope* scope)
: scope_stack_(scope_stack), outer_scope_(*scope_stack) {
*scope_stack_ = scope;
}
BlockState(Zone* zone, Scope** scope_stack)
: BlockState(scope_stack,
zone->New<Scope>(zone, *scope_stack, BLOCK_SCOPE)) {}
~BlockState() { *scope_stack_ = outer_scope_; }
private:
Scope** const scope_stack_;
Scope* const outer_scope_;
};
// ---------------------------------------------------------------------------
// Target is a support class to facilitate manipulation of the
// Parser's target_stack_ (the stack of potential 'break' and
// 'continue' statement targets). Upon construction, a new target is
// added; it is removed upon destruction.
// |labels| is a list of all labels that can be used as a target for break.
// |own_labels| is a list of all labels that an iteration statement is
// directly prefixed with, i.e. all the labels that a continue statement in
// the body can use to continue this iteration statement. This is always a
// subset of |labels|.
//
// Example: "l1: { l2: if (b) l3: l4: for (;;) s }"
// labels() of the Block will be l1.
// labels() of the ForStatement will be l2, l3, l4.
// own_labels() of the ForStatement will be l3, l4.
class Target {
public:
enum TargetType { TARGET_FOR_ANONYMOUS, TARGET_FOR_NAMED_ONLY };
Target(ParserBase* parser, BreakableStatementT statement,
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels, TargetType target_type)
: stack_(parser->function_state_->target_stack_address()),
statement_(statement),
labels_(labels),
own_labels_(own_labels),
target_type_(target_type),
previous_(*stack_) {
DCHECK_IMPLIES(Impl::IsIterationStatement(statement_),
target_type == Target::TARGET_FOR_ANONYMOUS);
DCHECK_IMPLIES(!Impl::IsIterationStatement(statement_),
own_labels == nullptr);
*stack_ = this;
}
~Target() { *stack_ = previous_; }
const Target* previous() const { return previous_; }
const BreakableStatementT statement() const { return statement_; }
const ZonePtrList<const AstRawString>* labels() const { return labels_; }
const ZonePtrList<const AstRawString>* own_labels() const {
return own_labels_;
}
bool is_iteration() const { return Impl::IsIterationStatement(statement_); }
bool is_target_for_anonymous() const {
return target_type_ == TARGET_FOR_ANONYMOUS;
}
private:
Target** const stack_;
const BreakableStatementT statement_;
const ZonePtrList<const AstRawString>* const labels_;
const ZonePtrList<const AstRawString>* const own_labels_;
const TargetType target_type_;
Target* const previous_;
};
Target* target_stack() { return *function_state_->target_stack_address(); }
BreakableStatementT LookupBreakTarget(IdentifierT label) {
bool anonymous = impl()->IsNull(label);
for (const Target* t = target_stack(); t != nullptr; t = t->previous()) {
if ((anonymous && t->is_target_for_anonymous()) ||
(!anonymous &&
ContainsLabel(t->labels(),
impl()->GetRawNameFromIdentifier(label)))) {
return t->statement();
}
}
return impl()->NullStatement();
}
IterationStatementT LookupContinueTarget(IdentifierT label) {
bool anonymous = impl()->IsNull(label);
for (const Target* t = target_stack(); t != nullptr; t = t->previous()) {
if (!t->is_iteration()) continue;
DCHECK(t->is_target_for_anonymous());
if (anonymous || ContainsLabel(t->own_labels(),
impl()->GetRawNameFromIdentifier(label))) {
return impl()->AsIterationStatement(t->statement());
}
}
return impl()->NullStatement();
}
class FunctionState final : public BlockState {
public:
FunctionState(FunctionState** function_state_stack, Scope** scope_stack,
DeclarationScope* scope);
~FunctionState();
DeclarationScope* scope() const { return scope_->AsDeclarationScope(); }
void AddProperty() { expected_property_count_++; }
int expected_property_count() { return expected_property_count_; }
void DisableOptimization(BailoutReason reason) {
dont_optimize_reason_ = reason;
}
BailoutReason dont_optimize_reason() { return dont_optimize_reason_; }
void AddSuspend() { suspend_count_++; }
int suspend_count() const { return suspend_count_; }
bool CanSuspend() const { return suspend_count_ > 0; }
FunctionKind kind() const { return scope()->function_kind(); }
bool next_function_is_likely_called() const {
return next_function_is_likely_called_;
}
bool previous_function_was_likely_called() const {
return previous_function_was_likely_called_;
}
void set_next_function_is_likely_called() {
next_function_is_likely_called_ = !FLAG_max_lazy;
}
void RecordFunctionOrEvalCall() { contains_function_or_eval_ = true; }
bool contains_function_or_eval() const {
return contains_function_or_eval_;
}
class FunctionOrEvalRecordingScope {
public:
explicit FunctionOrEvalRecordingScope(FunctionState* state)
: state_and_prev_value_(state, state->contains_function_or_eval_) {
state->contains_function_or_eval_ = false;
}
~FunctionOrEvalRecordingScope() {
bool found = state_and_prev_value_->contains_function_or_eval_;
if (!found) {
state_and_prev_value_->contains_function_or_eval_ =
state_and_prev_value_.GetPayload();
}
}
private:
PointerWithPayload<FunctionState, bool, 1> state_and_prev_value_;
};
class LoopScope final {
public:
explicit LoopScope(FunctionState* function_state)
: function_state_(function_state) {
function_state_->loop_nesting_depth_++;
}
~LoopScope() { function_state_->loop_nesting_depth_--; }
private:
FunctionState* function_state_;
};
int loop_nesting_depth() const { return loop_nesting_depth_; }
Target** target_stack_address() { return &target_stack_; }
private:
// Properties count estimation.
int expected_property_count_;
// How many suspends are needed for this function.
int suspend_count_;
// How deeply nested we currently are in this function.
int loop_nesting_depth_ = 0;
FunctionState** function_state_stack_;
FunctionState* outer_function_state_;
DeclarationScope* scope_;
Target* target_stack_ = nullptr; // for break, continue statements
// A reason, if any, why this function should not be optimized.
BailoutReason dont_optimize_reason_;
// Record whether the next (=== immediately following) function literal is
// preceded by a parenthesis / exclamation mark. Also record the previous
// state.
// These are managed by the FunctionState constructor; the caller may only
// call set_next_function_is_likely_called.
bool next_function_is_likely_called_;
bool previous_function_was_likely_called_;
// Track if a function or eval occurs within this FunctionState
bool contains_function_or_eval_;
friend Impl;
};
struct DeclarationDescriptor {
VariableMode mode;
VariableKind kind;
int declaration_pos;
int initialization_pos;
};
struct DeclarationParsingResult {
struct Declaration {
Declaration(ExpressionT pattern, ExpressionT initializer)
: pattern(pattern), initializer(initializer) {
DCHECK_IMPLIES(Impl::IsNull(pattern), Impl::IsNull(initializer));
}
ExpressionT pattern;
ExpressionT initializer;
int value_beg_pos = kNoSourcePosition;
};
DeclarationParsingResult()
: first_initializer_loc(Scanner::Location::invalid()),
bindings_loc(Scanner::Location::invalid()) {}
DeclarationDescriptor descriptor;
std::vector<Declaration> declarations;
Scanner::Location first_initializer_loc;
Scanner::Location bindings_loc;
};
struct CatchInfo {
public:
explicit CatchInfo(ParserBase* parser)
: pattern(parser->impl()->NullExpression()),
variable(nullptr),
scope(nullptr) {}
ExpressionT pattern;
Variable* variable;
Scope* scope;
};
struct ForInfo {
public:
explicit ForInfo(ParserBase* parser)
: bound_names(1, parser->zone()),
mode(ForEachStatement::ENUMERATE),
position(kNoSourcePosition),
parsing_result() {}
ZonePtrList<const AstRawString> bound_names;
ForEachStatement::VisitMode mode;
int position;
DeclarationParsingResult parsing_result;
};
struct ClassInfo {
public:
explicit ClassInfo(ParserBase* parser)
: extends(parser->impl()->NullExpression()),
public_members(parser->impl()->NewClassPropertyList(4)),
private_members(parser->impl()->NewClassPropertyList(4)),
static_fields(parser->impl()->NewClassPropertyList(4)),
instance_fields(parser->impl()->NewClassPropertyList(4)),
constructor(parser->impl()->NullExpression()),
has_seen_constructor(false),
has_name_static_property(false),
has_static_computed_names(false),
has_static_class_fields(false),
has_static_private_methods(false),
has_instance_members(false),
requires_brand(false),
is_anonymous(false),
has_private_methods(false),
static_fields_scope(nullptr),
instance_members_scope(nullptr),
computed_field_count(0) {}
ExpressionT extends;
ClassPropertyListT public_members;
ClassPropertyListT private_members;
ClassPropertyListT static_fields;
ClassPropertyListT instance_fields;
FunctionLiteralT constructor;
bool has_seen_constructor;
bool has_name_static_property;
bool has_static_computed_names;
bool has_static_class_fields;
bool has_static_private_methods;
bool has_instance_members;
bool requires_brand;
bool is_anonymous;
bool has_private_methods;
DeclarationScope* static_fields_scope;
DeclarationScope* instance_members_scope;
int computed_field_count;
};
enum class PropertyPosition { kObjectLiteral, kClassLiteral };
struct ParsePropertyInfo {
public:
explicit ParsePropertyInfo(ParserBase* parser,
AccumulationScope* accumulation_scope = nullptr)
: accumulation_scope(accumulation_scope),
name(parser->impl()->NullIdentifier()),
position(PropertyPosition::kClassLiteral),
function_flags(ParseFunctionFlag::kIsNormal),
kind(ParsePropertyKind::kNotSet),
is_computed_name(false),
is_private(false),
is_static(false),
is_rest(false) {}
bool ParsePropertyKindFromToken(Token::Value token) {
// This returns true, setting the property kind, iff the given token is
// one which must occur after a property name, indicating that the
// previous token was in fact a name and not a modifier (like the "get" in
// "get x").
switch (token) {
case Token::COLON:
kind = ParsePropertyKind::kValue;
return true;
case Token::COMMA:
kind = ParsePropertyKind::kShorthand;
return true;
case Token::RBRACE:
kind = ParsePropertyKind::kShorthandOrClassField;
return true;
case Token::ASSIGN:
kind = ParsePropertyKind::kAssign;
return true;
case Token::LPAREN:
kind = ParsePropertyKind::kMethod;
return true;
case Token::MUL:
case Token::SEMICOLON:
kind = ParsePropertyKind::kClassField;
return true;
default:
break;
}
return false;
}
AccumulationScope* accumulation_scope;
IdentifierT name;
PropertyPosition position;
ParseFunctionFlags function_flags;
ParsePropertyKind kind;
bool is_computed_name;
bool is_private;
bool is_static;
bool is_rest;
};
void DeclareLabel(ZonePtrList<const AstRawString>** labels,
ZonePtrList<const AstRawString>** own_labels,
const AstRawString* label) {
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 =
zone()->template New<ZonePtrList<const AstRawString>>(1, zone());
*own_labels =
zone()->template New<ZonePtrList<const AstRawString>>(1, zone());
} else {
if (*own_labels == nullptr) {
*own_labels =
zone()->template New<ZonePtrList<const AstRawString>>(1, zone());
}
}
(*labels)->Add(label, zone());
(*own_labels)->Add(label, zone());
}
bool ContainsLabel(const 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;
}
bool TargetStackContainsLabel(const AstRawString* label) {
for (const Target* t = target_stack(); t != nullptr; t = t->previous()) {
if (ContainsLabel(t->labels(), label)) return true;
}
return false;
}
ClassLiteralProperty::Kind ClassPropertyKindFor(ParsePropertyKind kind) {
switch (kind) {
case ParsePropertyKind::kAccessorGetter:
return ClassLiteralProperty::GETTER;
case ParsePropertyKind::kAccessorSetter:
return ClassLiteralProperty::SETTER;
case ParsePropertyKind::kMethod:
return ClassLiteralProperty::METHOD;
case ParsePropertyKind::kClassField:
return ClassLiteralProperty::FIELD;
default:
// Only returns for deterministic kinds
UNREACHABLE();
}
}
VariableMode GetVariableMode(ClassLiteralProperty::Kind kind) {
switch (kind) {
case ClassLiteralProperty::Kind::FIELD:
return VariableMode::kConst;
case ClassLiteralProperty::Kind::METHOD:
return VariableMode::kPrivateMethod;
case ClassLiteralProperty::Kind::GETTER:
return VariableMode::kPrivateGetterOnly;
case ClassLiteralProperty::Kind::SETTER:
return VariableMode::kPrivateSetterOnly;
}
}
const AstRawString* ClassFieldVariableName(AstValueFactory* ast_value_factory,
int index) {
std::string name = ".class-field-" + std::to_string(index);
return ast_value_factory->GetOneByteString(name.c_str());
}
DeclarationScope* NewScriptScope(REPLMode repl_mode) const {
return zone()->template New<DeclarationScope>(zone(), ast_value_factory(),
repl_mode);
}
DeclarationScope* NewVarblockScope() const {
return zone()->template New<DeclarationScope>(zone(), scope(), BLOCK_SCOPE);
}
ModuleScope* NewModuleScope(DeclarationScope* parent) const {
return zone()->template New<ModuleScope>(parent, ast_value_factory());
}
DeclarationScope* NewEvalScope(Scope* parent) const {
return zone()->template New<DeclarationScope>(zone(), parent, EVAL_SCOPE);
}
ClassScope* NewClassScope(Scope* parent, bool is_anonymous) const {
return zone()->template New<ClassScope>(zone(), parent, is_anonymous);
}
Scope* NewScope(ScopeType scope_type) const {
return NewScopeWithParent(scope(), scope_type);
}
// This constructor should only be used when absolutely necessary. Most scopes
// should automatically use scope() as parent, and be fine with
// NewScope(ScopeType) above.
Scope* NewScopeWithParent(Scope* parent, ScopeType scope_type) const {
// Must always use the specific constructors for the blocklisted scope
// types.
DCHECK_NE(FUNCTION_SCOPE, scope_type);
DCHECK_NE(SCRIPT_SCOPE, scope_type);
DCHECK_NE(MODULE_SCOPE, scope_type);
DCHECK_NOT_NULL(parent);
return zone()->template New<Scope>(zone(), parent, scope_type);
}
// Creates a function scope that always allocates in zone(). The function
// scope itself is either allocated in zone() or in target_zone if one is
// passed in.
DeclarationScope* NewFunctionScope(FunctionKind kind,
Zone* parse_zone = nullptr) const {
DCHECK(ast_value_factory());
if (parse_zone == nullptr) parse_zone = zone();
DeclarationScope* result = zone()->template New<DeclarationScope>(
parse_zone, scope(), FUNCTION_SCOPE, kind);
// Record presence of an inner function scope
function_state_->RecordFunctionOrEvalCall();
// TODO(verwaest): Move into the DeclarationScope constructor.
if (!IsArrowFunction(kind)) {
result->DeclareDefaultFunctionVariables(ast_value_factory());
}
return result;
}
V8_INLINE DeclarationScope* GetDeclarationScope() const {
return scope()->GetDeclarationScope();
}
V8_INLINE DeclarationScope* GetClosureScope() const {
return scope()->GetClosureScope();
}
VariableProxy* NewRawVariable(const AstRawString* name, int pos) {
return factory()->ast_node_factory()->NewVariableProxy(
name, NORMAL_VARIABLE, pos);
}
VariableProxy* NewUnresolved(const AstRawString* name) {
return scope()->NewUnresolved(factory()->ast_node_factory(), name,
scanner()->location().beg_pos);
}
VariableProxy* NewUnresolved(const AstRawString* name, int begin_pos,
VariableKind kind = NORMAL_VARIABLE) {
return scope()->NewUnresolved(factory()->ast_node_factory(), name,
begin_pos, kind);
}
Scanner* scanner() const { return scanner_; }
AstValueFactory* ast_value_factory() const { return ast_value_factory_; }
int position() const { return scanner_->location().beg_pos; }
int peek_position() const { return scanner_->peek_location().beg_pos; }
int end_position() const { return scanner_->location().end_pos; }
int peek_end_position() const { return scanner_->peek_location().end_pos; }
bool stack_overflow() const {
return pending_error_handler()->stack_overflow();
}
void set_stack_overflow() {
scanner_->set_parser_error();
pending_error_handler()->set_stack_overflow();
}
void CheckStackOverflow() {
// Any further calls to Next or peek will return the illegal token.
if (GetCurrentStackPosition() < stack_limit_) set_stack_overflow();
}
V8_INLINE Token::Value peek() { return scanner()->peek(); }
// Returns the position past the following semicolon (if it exists), and the
// position past the end of the current token otherwise.
int PositionAfterSemicolon() {
return (peek() == Token::SEMICOLON) ? peek_end_position() : end_position();
}
V8_INLINE Token::Value PeekAhead() { return scanner()->PeekAhead(); }
V8_INLINE Token::Value Next() { return scanner()->Next(); }
V8_INLINE void Consume(Token::Value token) {
Token::Value next = scanner()->Next();
USE(next);
USE(token);
DCHECK_IMPLIES(!has_error(), next == token);
}
V8_INLINE bool Check(Token::Value token) {
Token::Value next = scanner()->peek();
if (next == token) {
Consume(next);
return true;
}
return false;
}
void Expect(Token::Value token) {
Token::Value next = Next();
if (V8_UNLIKELY(next != token)) {
ReportUnexpectedToken(next);
}
}
void ExpectSemicolon() {
// Check for automatic semicolon insertion according to
// the rules given in ECMA-262, section 7.9, page 21.
Token::Value tok = peek();
if (V8_LIKELY(tok == Token::SEMICOLON)) {
Next();
return;
}
if (V8_LIKELY(scanner()->HasLineTerminatorBeforeNext() ||
Token::IsAutoSemicolon(tok))) {
return;
}
if (scanner()->current_token() == Token::AWAIT && !is_async_function()) {
ReportMessageAt(scanner()->location(),
flags().allow_harmony_top_level_await()
? MessageTemplate::kAwaitNotInAsyncContext
: MessageTemplate::kAwaitNotInAsyncFunction);
return;
}
ReportUnexpectedToken(Next());
}
bool peek_any_identifier() { return Token::IsAnyIdentifier(peek()); }
bool PeekContextualKeyword(const AstRawString* name) {
return peek() == Token::IDENTIFIER &&
!scanner()->next_literal_contains_escapes() &&
scanner()->NextSymbol(ast_value_factory()) == name;
}
bool CheckContextualKeyword(const AstRawString* name) {
if (PeekContextualKeyword(name)) {
Consume(Token::IDENTIFIER);
return true;
}
return false;
}
void ExpectContextualKeyword(const AstRawString* name,
const char* fullname = nullptr, int pos = -1) {
Expect(Token::IDENTIFIER);
if (V8_UNLIKELY(scanner()->CurrentSymbol(ast_value_factory()) != name)) {
ReportUnexpectedToken(scanner()->current_token());
}
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
const char* full = fullname == nullptr
? reinterpret_cast<const char*>(name->raw_data())
: fullname;
int start = pos == -1 ? position() : pos;
impl()->ReportMessageAt(Scanner::Location(start, end_position()),
MessageTemplate::kInvalidEscapedMetaProperty,
full);
}
}
bool CheckInOrOf(ForEachStatement::VisitMode* visit_mode) {
if (Check(Token::IN)) {
*visit_mode = ForEachStatement::ENUMERATE;
return true;
} else if (CheckContextualKeyword(ast_value_factory()->of_string())) {
*visit_mode = ForEachStatement::ITERATE;
return true;
}
return false;
}
bool PeekInOrOf() {
return peek() == Token::IN ||
PeekContextualKeyword(ast_value_factory()->of_string());
}
// Checks whether an octal literal was last seen between beg_pos and end_pos.
// Only called for strict mode strings.
void CheckStrictOctalLiteral(int beg_pos, int end_pos) {
Scanner::Location octal = scanner()->octal_position();
if (octal.IsValid() && beg_pos <= octal.beg_pos &&
octal.end_pos <= end_pos) {
MessageTemplate message = scanner()->octal_message();
DCHECK_NE(message, MessageTemplate::kNone);
impl()->ReportMessageAt(octal, message);
scanner()->clear_octal_position();
if (message == MessageTemplate::kStrictDecimalWithLeadingZero) {
impl()->CountUsage(v8::Isolate::kDecimalWithLeadingZeroInStrictMode);
}
}
}
// Checks if an octal literal or an invalid hex or unicode escape sequence
// appears in the current template literal token. In the presence of such,
// either returns false or reports an error, depending on should_throw.
// Otherwise returns true.
inline bool CheckTemplateEscapes(bool should_throw) {
DCHECK(Token::IsTemplate(scanner()->current_token()));
if (!scanner()->has_invalid_template_escape()) return true;
// Handle error case(s)
if (should_throw) {
impl()->ReportMessageAt(scanner()->invalid_template_escape_location(),
scanner()->invalid_template_escape_message());
}
scanner()->clear_invalid_template_escape_message();
return should_throw;
}
ExpressionT ParsePossibleDestructuringSubPattern(AccumulationScope* scope);
void ClassifyParameter(IdentifierT parameter, int beg_pos, int end_pos);
void ClassifyArrowParameter(AccumulationScope* accumulation_scope,
int position, ExpressionT parameter);
// Checking the name of a function literal. This has to be done after parsing
// the function, since the function can declare itself strict.
void CheckFunctionName(LanguageMode language_mode, IdentifierT function_name,
FunctionNameValidity function_name_validity,
const Scanner::Location& function_name_loc) {
if (impl()->IsNull(function_name)) return;
if (function_name_validity == kSkipFunctionNameCheck) return;
// The function name needs to be checked in strict mode.
if (is_sloppy(language_mode)) return;
if (impl()->IsEvalOrArguments(function_name)) {
impl()->ReportMessageAt(function_name_loc,
MessageTemplate::kStrictEvalArguments);
return;
}
if (function_name_validity == kFunctionNameIsStrictReserved) {
impl()->ReportMessageAt(function_name_loc,
MessageTemplate::kUnexpectedStrictReserved);
return;
}
}
typename Types::Factory* factory() { return &ast_node_factory_; }
DeclarationScope* GetReceiverScope() const {
return scope()->GetReceiverScope();
}
LanguageMode language_mode() { return scope()->language_mode(); }
void RaiseLanguageMode(LanguageMode mode) {
LanguageMode old = scope()->language_mode();
impl()->SetLanguageMode(scope(), old > mode ? old : mode);
}
bool is_generator() const {
return IsGeneratorFunction(function_state_->kind());
}
bool is_async_function() const {
return IsAsyncFunction(function_state_->kind());
}
bool is_async_generator() const {
return IsAsyncGeneratorFunction(function_state_->kind());
}
bool is_resumable() const {
return IsResumableFunction(function_state_->kind());
}
bool is_await_allowed() const {
return is_async_function() || (flags().allow_harmony_top_level_await() &&
IsModule(function_state_->kind()));
}
const PendingCompilationErrorHandler* pending_error_handler() const {
return pending_error_handler_;
}
PendingCompilationErrorHandler* pending_error_handler() {
return pending_error_handler_;
}
// Report syntax errors.
V8_NOINLINE void ReportMessage(MessageTemplate message) {
Scanner::Location source_location = scanner()->location();
impl()->ReportMessageAt(source_location, message,
static_cast<const char*>(nullptr));
}
template <typename T>
V8_NOINLINE void ReportMessage(MessageTemplate message, T arg) {
Scanner::Location source_location = scanner()->location();
impl()->ReportMessageAt(source_location, message, arg);
}
V8_NOINLINE void ReportMessageAt(Scanner::Location location,
MessageTemplate message) {
impl()->ReportMessageAt(location, message,
static_cast<const char*>(nullptr));
}
V8_NOINLINE void ReportUnexpectedToken(Token::Value token);
void ValidateFormalParameters(LanguageMode language_mode,
const FormalParametersT& parameters,
bool allow_duplicates) {
if (!allow_duplicates) parameters.ValidateDuplicate(impl());
if (is_strict(language_mode)) parameters.ValidateStrictMode(impl());
}
// Needs to be called if the reference needs to be available from the current
// point. It causes the receiver to be context allocated if necessary.
// Returns the receiver variable that we're referencing.
V8_INLINE Variable* UseThis() {
DeclarationScope* closure_scope = scope()->GetClosureScope();
DeclarationScope* receiver_scope = closure_scope->GetReceiverScope();
Variable* var = receiver_scope->receiver();
var->set_is_used();
if (closure_scope == receiver_scope) {
// It's possible that we're parsing the head of an arrow function, in
// which case we haven't realized yet that closure_scope !=
// receiver_scope. Mark through the ExpressionScope for now.
expression_scope()->RecordThisUse();
} else {
closure_scope->set_has_this_reference();
var->ForceContextAllocation();
}
return var;
}
V8_INLINE IdentifierT ParseAndClassifyIdentifier(Token::Value token);
// Parses an identifier or a strict mode future reserved word. Allows passing
// in function_kind for the case of parsing the identifier in a function
// expression, where the relevant "function_kind" bit is of the function being
// parsed, not the containing function.
V8_INLINE IdentifierT ParseIdentifier(FunctionKind function_kind);
V8_INLINE IdentifierT ParseIdentifier() {
return ParseIdentifier(function_state_->kind());
}
// Same as above but additionally disallows 'eval' and 'arguments' in strict
// mode.
IdentifierT ParseNonRestrictedIdentifier();
// This method should be used to ambiguously parse property names that can
// become destructuring identifiers.
V8_INLINE IdentifierT ParsePropertyName();
ExpressionT ParsePropertyOrPrivatePropertyName();
ExpressionT ParseRegExpLiteral();
ExpressionT ParseBindingPattern();
ExpressionT ParsePrimaryExpression();
// Use when parsing an expression that is known to not be a pattern or part of
// a pattern.
V8_INLINE ExpressionT ParseExpression();
V8_INLINE ExpressionT ParseAssignmentExpression();
// These methods do not wrap the parsing of the expression inside a new
// expression_scope; they use the outer expression_scope instead. They should
// be used whenever we're parsing something with the "cover" grammar that
// recognizes both patterns and non-patterns (which roughly corresponds to
// what's inside the parentheses generated by the symbol
// "CoverParenthesizedExpressionAndArrowParameterList" in the ES 2017
// specification).
ExpressionT ParseExpressionCoverGrammar();
ExpressionT ParseAssignmentExpressionCoverGrammar();
ExpressionT ParseArrowParametersWithRest(ExpressionListT* list,
AccumulationScope* scope,
int seen_variables);
ExpressionT ParseArrayLiteral();
inline static bool IsAccessor(ParsePropertyKind kind) {
return base::IsInRange(kind, ParsePropertyKind::kAccessorGetter,
ParsePropertyKind::kAccessorSetter);
}
ExpressionT ParseProperty(ParsePropertyInfo* prop_info);
ExpressionT ParseObjectLiteral();
ClassLiteralPropertyT ParseClassPropertyDefinition(
ClassInfo* class_info, ParsePropertyInfo* prop_info, bool has_extends);
void CheckClassFieldName(IdentifierT name, bool is_static);
void CheckClassMethodName(IdentifierT name, ParsePropertyKind type,
ParseFunctionFlags flags, bool is_static,
bool* has_seen_constructor);
ExpressionT ParseMemberInitializer(ClassInfo* class_info, int beg_pos,
bool is_static);
ObjectLiteralPropertyT ParseObjectPropertyDefinition(
ParsePropertyInfo* prop_info, bool* has_seen_proto);
void ParseArguments(
ExpressionListT* args, bool* has_spread,
ParsingArrowHeadFlag maybe_arrow = kCertainlyNotArrowHead);
ExpressionT ParseYieldExpression();
V8_INLINE ExpressionT ParseConditionalExpression();
ExpressionT ParseConditionalContinuation(ExpressionT expression, int pos);
ExpressionT ParseLogicalExpression();
ExpressionT ParseCoalesceExpression(ExpressionT expression);
ExpressionT ParseBinaryContinuation(ExpressionT x, int prec, int prec1);
V8_INLINE ExpressionT ParseBinaryExpression(int prec);
ExpressionT ParseUnaryOrPrefixExpression();
ExpressionT ParseAwaitExpression();
V8_INLINE ExpressionT ParseUnaryExpression();
V8_INLINE ExpressionT ParsePostfixExpression();
V8_NOINLINE ExpressionT ParsePostfixContinuation(ExpressionT expression,
int lhs_beg_pos);
V8_INLINE ExpressionT ParseLeftHandSideExpression();
ExpressionT ParseLeftHandSideContinuation(ExpressionT expression);
ExpressionT ParseMemberWithPresentNewPrefixesExpression();
ExpressionT ParseFunctionExpression();
V8_INLINE ExpressionT ParseMemberExpression();
V8_INLINE ExpressionT
ParseMemberExpressionContinuation(ExpressionT expression) {
if (!Token::IsMember(peek())) return expression;
return DoParseMemberExpressionContinuation(expression);
}
ExpressionT DoParseMemberExpressionContinuation(ExpressionT expression);
ExpressionT ParseArrowFunctionLiteral(const FormalParametersT& parameters);
void ParseAsyncFunctionBody(Scope* scope, StatementListT* body);
ExpressionT ParseAsyncFunctionLiteral();
ExpressionT ParseClassLiteral(IdentifierT name,
Scanner::Location class_name_location,
bool name_is_strict_reserved,
int class_token_pos);
ExpressionT ParseTemplateLiteral(ExpressionT tag, int start, bool tagged);
ExpressionT ParseSuperExpression(bool is_new);
ExpressionT ParseImportExpressions();
ExpressionT ParseNewTargetExpression();
V8_INLINE void ParseFormalParameter(FormalParametersT* parameters);
void ParseFormalParameterList(FormalParametersT* parameters);
void CheckArityRestrictions(int param_count, FunctionKind function_type,
bool has_rest, int formals_start_pos,
int formals_end_pos);
void ParseVariableDeclarations(VariableDeclarationContext var_context,
DeclarationParsingResult* parsing_result,
ZonePtrList<const AstRawString>* names);
StatementT ParseAsyncFunctionDeclaration(
ZonePtrList<const AstRawString>* names, bool default_export);
StatementT ParseFunctionDeclaration();
StatementT ParseHoistableDeclaration(ZonePtrList<const AstRawString>* names,
bool default_export);
StatementT ParseHoistableDeclaration(int pos, ParseFunctionFlags flags,
ZonePtrList<const AstRawString>* names,
bool default_export);
StatementT ParseClassDeclaration(ZonePtrList<const AstRawString>* names,
bool default_export);
StatementT ParseNativeDeclaration();
// Whether we're parsing a single-expression arrow function or something else.
enum class FunctionBodyType { kExpression, kBlock };
// Consumes the ending }.
void ParseFunctionBody(StatementListT* body, IdentifierT function_name,
int pos, const FormalParametersT& parameters,
FunctionKind kind,
FunctionSyntaxKind function_syntax_kind,
FunctionBodyType body_type);
// Check if the scope has conflicting var/let declarations from different
// scopes. This covers for example
//
// function f() { { { var x; } let x; } }
// function g() { { var x; let x; } }
//
// The var declarations are hoisted to the function scope, but originate from
// a scope where the name has also been let bound or the var declaration is
// hoisted over such a scope.
void CheckConflictingVarDeclarations(DeclarationScope* scope) {
if (has_error()) return;
bool allowed_catch_binding_var_redeclaration = false;
Declaration* decl = scope->CheckConflictingVarDeclarations(
&allowed_catch_binding_var_redeclaration);
if (allowed_catch_binding_var_redeclaration) {
impl()->CountUsage(v8::Isolate::kVarRedeclaredCatchBinding);
}
if (decl != nullptr) {
// In ES6, conflicting variable bindings are early errors.
const AstRawString* name = decl->var()->raw_name();
int position = decl->position();
Scanner::Location location =
position == kNoSourcePosition
? Scanner::Location::invalid()
: Scanner::Location(position, position + 1);
impl()->ReportMessageAt(location, MessageTemplate::kVarRedeclaration,
name);
}
}
// TODO(nikolaos, marja): The first argument should not really be passed
// by value. The method is expected to add the parsed statements to the
// list. This works because in the case of the parser, StatementListT is
// a pointer whereas the preparser does not really modify the body.
V8_INLINE void ParseStatementList(StatementListT* body,
Token::Value end_token);
StatementT ParseStatementListItem();
StatementT ParseStatement(ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
return ParseStatement(labels, own_labels,
kDisallowLabelledFunctionStatement);
}
StatementT ParseStatement(ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels,
AllowLabelledFunctionStatement allow_function);
BlockT ParseBlock(ZonePtrList<const AstRawString>* labels);
// Parse a SubStatement in strict mode, or with an extra block scope in
// sloppy mode to handle
// ES#sec-functiondeclarations-in-ifstatement-statement-clauses
StatementT ParseScopedStatement(ZonePtrList<const AstRawString>* labels);
StatementT ParseVariableStatement(VariableDeclarationContext var_context,
ZonePtrList<const AstRawString>* names);
// Magical syntax support.
ExpressionT ParseV8Intrinsic();
StatementT ParseDebuggerStatement();
StatementT ParseExpressionOrLabelledStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels,
AllowLabelledFunctionStatement allow_function);
StatementT ParseIfStatement(ZonePtrList<const AstRawString>* labels);
StatementT ParseContinueStatement();
StatementT ParseBreakStatement(ZonePtrList<const AstRawString>* labels);
StatementT ParseReturnStatement();
StatementT ParseWithStatement(ZonePtrList<const AstRawString>* labels);
StatementT ParseDoWhileStatement(ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels);
StatementT ParseWhileStatement(ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels);
StatementT ParseThrowStatement();
StatementT ParseSwitchStatement(ZonePtrList<const AstRawString>* labels);
V8_INLINE StatementT ParseTryStatement();
StatementT ParseForStatement(ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels);
StatementT ParseForEachStatementWithDeclarations(
int stmt_pos, ForInfo* for_info, ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels, Scope* inner_block_scope);
StatementT ParseForEachStatementWithoutDeclarations(
int stmt_pos, ExpressionT expression, int lhs_beg_pos, int lhs_end_pos,
ForInfo* for_info, ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels);
// Parse a C-style for loop: 'for (<init>; <cond>; <next>) { ... }'
// "for (<init>;" is assumed to have been parser already.
ForStatementT ParseStandardForLoop(
int stmt_pos, ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels, ExpressionT* cond,
StatementT* next, StatementT* body);
// Same as the above, but handles those cases where <init> is a
// lexical variable declaration.
StatementT ParseStandardForLoopWithLexicalDeclarations(
int stmt_pos, StatementT init, ForInfo* for_info,
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels);
StatementT ParseForAwaitStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels);
V8_INLINE bool IsLet(const AstRawString* identifier) const {
return identifier == ast_value_factory()->let_string();
}
bool IsNextLetKeyword();
// Checks if the expression is a valid reference expression (e.g., on the
// left-hand side of assignments). Although ruled out by ECMA as early errors,
// we allow calls for web compatibility and rewrite them to a runtime throw.
// Modern language features can be exempted from this hack by passing
// early_error = true.
ExpressionT RewriteInvalidReferenceExpression(ExpressionT expression,
int beg_pos, int end_pos,
MessageTemplate message,
bool early_error);
bool IsValidReferenceExpression(ExpressionT expression);
bool IsAssignableIdentifier(ExpressionT expression) {
if (!impl()->IsIdentifier(expression)) return false;
if (is_strict(language_mode()) &&
impl()->IsEvalOrArguments(impl()->AsIdentifier(expression))) {
return false;
}
return true;
}
FunctionKind FunctionKindForImpl(bool is_method, ParseFunctionFlags flags) {
static const FunctionKind kFunctionKinds[][2][2] = {
{
// is_method=false
{// is_generator=false
FunctionKind::kNormalFunction, FunctionKind::kAsyncFunction},
{// is_generator=true
FunctionKind::kGeneratorFunction,
FunctionKind::kAsyncGeneratorFunction},
},
{
// is_method=true
{// is_generator=false
FunctionKind::kConciseMethod, FunctionKind::kAsyncConciseMethod},
{// is_generator=true
FunctionKind::kConciseGeneratorMethod,
FunctionKind::kAsyncConciseGeneratorMethod},
}};
return kFunctionKinds[is_method]
[(flags & ParseFunctionFlag::kIsGenerator) != 0]
[(flags & ParseFunctionFlag::kIsAsync) != 0];
}
inline FunctionKind FunctionKindFor(ParseFunctionFlags flags) {
const bool kIsMethod = false;
return FunctionKindForImpl(kIsMethod, flags);
}
inline FunctionKind MethodKindFor(ParseFunctionFlags flags) {
const bool kIsMethod = true;
return FunctionKindForImpl(kIsMethod, flags);
}
// Keep track of eval() calls since they disable all local variable
// optimizations. This checks if expression is an eval call, and if yes,
// forwards the information to scope.
Call::PossiblyEval CheckPossibleEvalCall(ExpressionT expression,
bool is_optional_call,
Scope* scope) {
if (impl()->IsIdentifier(expression) &&
impl()->IsEval(impl()->AsIdentifier(expression)) && !is_optional_call) {
function_state_->RecordFunctionOrEvalCall();
scope->RecordEvalCall();
return Call::IS_POSSIBLY_EVAL;
}
return Call::NOT_EVAL;
}
// Convenience method which determines the type of return statement to emit
// depending on the current function type.
inline StatementT BuildReturnStatement(ExpressionT expr, int pos,
int end_pos = kNoSourcePosition) {
if (impl()->IsNull(expr)) {
expr = factory()->NewUndefinedLiteral(kNoSourcePosition);
} else if (is_async_generator()) {
// In async generators, if there is an explicit operand to the return
// statement, await the operand.
expr = factory()->NewAwait(expr, kNoSourcePosition);
function_state_->AddSuspend();
}
if (is_async_function()) {
return factory()->NewAsyncReturnStatement(expr, pos, end_pos);
}
return factory()->NewReturnStatement(expr, pos, end_pos);
}
SourceTextModuleDescriptor* module() const {
return scope()->AsModuleScope()->module();
}
Scope* scope() const { return scope_; }
// Stack of expression expression_scopes.
// The top of the stack is always pointed to by expression_scope().
V8_INLINE ExpressionScope* expression_scope() const {
DCHECK_NOT_NULL(expression_scope_);
return expression_scope_;
}
bool MaybeParsingArrowhead() const {
return expression_scope_ != nullptr &&
expression_scope_->has_possible_arrow_parameter_in_scope_chain();
}
class AcceptINScope final {
public:
AcceptINScope(ParserBase* parser, bool accept_IN)
: parser_(parser), previous_accept_IN_(parser->accept_IN_) {
parser_->accept_IN_ = accept_IN;
}
~AcceptINScope() { parser_->accept_IN_ = previous_accept_IN_; }
private:
ParserBase* parser_;
bool previous_accept_IN_;
};
class ParameterParsingScope {
public:
ParameterParsingScope(Impl* parser, FormalParametersT* parameters)
: parser_(parser), parent_parameters_(parser_->parameters_) {
parser_->parameters_ = parameters;
}
~ParameterParsingScope() { parser_->parameters_ = parent_parameters_; }
private:
Impl* parser_;
FormalParametersT* parent_parameters_;
};
class FunctionParsingScope {
public:
explicit FunctionParsingScope(Impl* parser)
: parser_(parser), expression_scope_(parser_->expression_scope_) {
parser_->expression_scope_ = nullptr;
}
~FunctionParsingScope() { parser_->expression_scope_ = expression_scope_; }
private:
Impl* parser_;
ExpressionScope* expression_scope_;
};
std::vector<void*>* pointer_buffer() { return &pointer_buffer_; }
std::vector<std::pair<VariableProxy*, int>>* variable_buffer() {
return &variable_buffer_;
}
// Parser base's protected field members.
Scope* scope_; // Scope stack.
Scope* original_scope_; // The top scope for the current parsing item.
FunctionState* function_state_; // Function state stack.
v8::Extension* extension_;
FuncNameInferrer fni_;
AstValueFactory* ast_value_factory_; // Not owned.
typename Types::Factory ast_node_factory_;
RuntimeCallStats* runtime_call_stats_;
internal::Logger* logger_;
bool parsing_on_main_thread_;
uintptr_t stack_limit_;
PendingCompilationErrorHandler* pending_error_handler_;
// Parser base's private field members.
private:
Zone* zone_;
ExpressionScope* expression_scope_;
std::vector<void*> pointer_buffer_;
std::vector<std::pair<VariableProxy*, int>> variable_buffer_;
Scanner* scanner_;
const UnoptimizedCompileFlags flags_;
int function_literal_id_;
FunctionLiteral::EagerCompileHint default_eager_compile_hint_;
// This struct is used to move information about the next arrow function from
// the place where the arrow head was parsed to where the body will be parsed.
// Nothing can be parsed between the head and the body, so it will be consumed
// immediately after it's produced.
// Preallocating the struct as part of the parser minimizes the cost of
// supporting arrow functions on non-arrow expressions.
struct NextArrowFunctionInfo {
Scanner::Location strict_parameter_error_location =
Scanner::Location::invalid();
MessageTemplate strict_parameter_error_message = MessageTemplate::kNone;
DeclarationScope* scope = nullptr;
bool HasInitialState() const { return scope == nullptr; }
void Reset() {
scope = nullptr;
ClearStrictParameterError();
DCHECK(HasInitialState());
}
// Tracks strict-mode parameter violations of sloppy-mode arrow heads in
// case the function ends up becoming strict mode. Only one global place to
// track this is necessary since arrow functions with none-simple parameters
// cannot become strict-mode later on.
void ClearStrictParameterError() {
strict_parameter_error_location = Scanner::Location::invalid();
strict_parameter_error_message = MessageTemplate::kNone;
}
};
FormalParametersT* parameters_;
NextArrowFunctionInfo next_arrow_function_info_;
bool accept_IN_ = true;
bool allow_eval_cache_ = true;
};
template <typename Impl>
ParserBase<Impl>::FunctionState::FunctionState(
FunctionState** function_state_stack, Scope** scope_stack,
DeclarationScope* scope)
: BlockState(scope_stack, scope),
expected_property_count_(0),
suspend_count_(0),
function_state_stack_(function_state_stack),
outer_function_state_(*function_state_stack),
scope_(scope),
dont_optimize_reason_(BailoutReason::kNoReason),
next_function_is_likely_called_(false),
previous_function_was_likely_called_(false),
contains_function_or_eval_(false) {
*function_state_stack = this;
if (outer_function_state_) {
outer_function_state_->previous_function_was_likely_called_ =
outer_function_state_->next_function_is_likely_called_;
outer_function_state_->next_function_is_likely_called_ = false;
}
}
template <typename Impl>
ParserBase<Impl>::FunctionState::~FunctionState() {
*function_state_stack_ = outer_function_state_;
}
template <typename Impl>
void ParserBase<Impl>::ReportUnexpectedToken(Token::Value token) {
return impl()->ReportUnexpectedTokenAt(scanner_->location(), token);
}
template <typename Impl>
typename ParserBase<Impl>::IdentifierT
ParserBase<Impl>::ParseAndClassifyIdentifier(Token::Value next) {
DCHECK_EQ(scanner()->current_token(), next);
if (V8_LIKELY(base::IsInRange(next, Token::IDENTIFIER, Token::ASYNC))) {
IdentifierT name = impl()->GetIdentifier();
if (V8_UNLIKELY(impl()->IsArguments(name) &&
scope()->ShouldBanArguments())) {
ReportMessage(MessageTemplate::kArgumentsDisallowedInInitializer);
return impl()->EmptyIdentifierString();
}
return name;
}
if (!Token::IsValidIdentifier(next, language_mode(), is_generator(),
flags().is_module() || is_async_function())) {
ReportUnexpectedToken(next);
return impl()->EmptyIdentifierString();
}
if (next == Token::AWAIT) {
expression_scope()->RecordAsyncArrowParametersError(
scanner()->location(), MessageTemplate::kAwaitBindingIdentifier);
return impl()->GetIdentifier();
}
DCHECK(Token::IsStrictReservedWord(next));
expression_scope()->RecordStrictModeParameterError(
scanner()->location(), MessageTemplate::kUnexpectedStrictReserved);
return impl()->GetIdentifier();
}
template <class Impl>
typename ParserBase<Impl>::IdentifierT ParserBase<Impl>::ParseIdentifier(
FunctionKind function_kind) {
Token::Value next = Next();
if (!Token::IsValidIdentifier(
next, language_mode(), IsGeneratorFunction(function_kind),
flags().is_module() || IsAsyncFunction(function_kind))) {
ReportUnexpectedToken(next);
return impl()->EmptyIdentifierString();
}
return impl()->GetIdentifier();
}
template <typename Impl>
typename ParserBase<Impl>::IdentifierT
ParserBase<Impl>::ParseNonRestrictedIdentifier() {
IdentifierT result = ParseIdentifier();
if (is_strict(language_mode()) &&
V8_UNLIKELY(impl()->IsEvalOrArguments(result))) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kStrictEvalArguments);
}
return result;
}
template <typename Impl>
typename ParserBase<Impl>::IdentifierT ParserBase<Impl>::ParsePropertyName() {
Token::Value next = Next();
if (V8_LIKELY(Token::IsPropertyName(next))) {
if (peek() == Token::COLON) return impl()->GetSymbol();
return impl()->GetIdentifier();
}
ReportUnexpectedToken(next);
return impl()->EmptyIdentifierString();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParsePropertyOrPrivatePropertyName() {
int pos = position();
IdentifierT name;
ExpressionT key;
Token::Value next = Next();
if (V8_LIKELY(Token::IsPropertyName(next))) {
name = impl()->GetSymbol();
key = factory()->NewStringLiteral(name, pos);
} else if (next == Token::PRIVATE_NAME) {
// In the case of a top level function, we completely skip
// analysing it's scope, meaning, we don't have a chance to
// resolve private names and find that they are not enclosed in a
// class body.
//
// Here, we check if this is a new private name reference in a top
// level function and throw an error if so.
PrivateNameScopeIterator private_name_scope_iter(scope());
// Parse the identifier so that we can display it in the error message
name = impl()->GetIdentifier();
if (private_name_scope_iter.Done()) {
impl()->ReportMessageAt(Scanner::Location(pos, pos + 1),
MessageTemplate::kInvalidPrivateFieldResolution,
impl()->GetRawNameFromIdentifier(name));
return impl()->FailureExpression();
}
key =
impl()->ExpressionFromPrivateName(&private_name_scope_iter, name, pos);
} else {
ReportUnexpectedToken(next);
return impl()->FailureExpression();
}
impl()->PushLiteralName(name);
return key;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseRegExpLiteral() {
int pos = peek_position();
if (!scanner()->ScanRegExpPattern()) {
Next();
ReportMessage(MessageTemplate::kUnterminatedRegExp);
return impl()->FailureExpression();
}
IdentifierT js_pattern = impl()->GetNextSymbol();
Maybe<int> flags = scanner()->ScanRegExpFlags();
if (flags.IsNothing()) {
Next();
ReportMessage(MessageTemplate::kMalformedRegExpFlags);
return impl()->FailureExpression();
}
Next();
return factory()->NewRegExpLiteral(js_pattern, flags.FromJust(), pos);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseBindingPattern() {
// Pattern ::
// Identifier
// ArrayLiteral
// ObjectLiteral
int beg_pos = peek_position();
Token::Value token = peek();
ExpressionT result;
if (Token::IsAnyIdentifier(token)) {
IdentifierT name = ParseAndClassifyIdentifier(Next());
if (V8_UNLIKELY(is_strict(language_mode()) &&
impl()->IsEvalOrArguments(name))) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kStrictEvalArguments);
return impl()->FailureExpression();
}
return impl()->ExpressionFromIdentifier(name, beg_pos);
}
CheckStackOverflow();
if (token == Token::LBRACK) {
result = ParseArrayLiteral();
} else if (token == Token::LBRACE) {
result = ParseObjectLiteral();
} else {
ReportUnexpectedToken(Next());
return impl()->FailureExpression();
}
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParsePrimaryExpression() {
CheckStackOverflow();
// PrimaryExpression ::
// 'this'
// 'null'
// 'true'
// 'false'
// Identifier
// Number
// String
// ArrayLiteral
// ObjectLiteral
// RegExpLiteral
// ClassLiteral
// '(' Expression ')'
// TemplateLiteral
// do Block
// AsyncFunctionLiteral
int beg_pos = peek_position();
Token::Value token = peek();
if (Token::IsAnyIdentifier(token)) {
Consume(token);
FunctionKind kind = FunctionKind::kArrowFunction;
if (V8_UNLIKELY(token == Token::ASYNC &&
!scanner()->HasLineTerminatorBeforeNext() &&
!scanner()->literal_contains_escapes())) {
// async function ...
if (peek() == Token::FUNCTION) return ParseAsyncFunctionLiteral();
// async Identifier => ...
if (peek_any_identifier() && PeekAhead() == Token::ARROW) {
token = Next();
beg_pos = position();
kind = FunctionKind::kAsyncArrowFunction;
}
}
if (V8_UNLIKELY(peek() == Token::ARROW)) {
ArrowHeadParsingScope parsing_scope(impl(), kind);
IdentifierT name = ParseAndClassifyIdentifier(token);
ClassifyParameter(name, beg_pos, end_position());
ExpressionT result =
impl()->ExpressionFromIdentifier(name, beg_pos, InferName::kNo);
parsing_scope.SetInitializers(0, peek_position());
next_arrow_function_info_.scope = parsing_scope.ValidateAndCreateScope();
return result;
}
IdentifierT name = ParseAndClassifyIdentifier(token);
return impl()->ExpressionFromIdentifier(name, beg_pos);
}
if (Token::IsLiteral(token)) {
return impl()->ExpressionFromLiteral(Next(), beg_pos);
}
switch (token) {
case Token::NEW:
return ParseMemberWithPresentNewPrefixesExpression();
case Token::THIS: {
Consume(Token::THIS);
return impl()->NewThisExpression(beg_pos);
}
case Token::ASSIGN_DIV:
case Token::DIV:
return ParseRegExpLiteral();
case Token::FUNCTION:
return ParseFunctionExpression();
case Token::SUPER: {
const bool is_new = false;
return ParseSuperExpression(is_new);
}
case Token::IMPORT:
return ParseImportExpressions();
case Token::LBRACK:
return ParseArrayLiteral();
case Token::LBRACE:
return ParseObjectLiteral();
case Token::LPAREN: {
Consume(Token::LPAREN);
if (Check(Token::RPAREN)) {
// ()=>x. The continuation that consumes the => is in
// ParseAssignmentExpressionCoverGrammar.
if (peek() != Token::ARROW) ReportUnexpectedToken(Token::RPAREN);
next_arrow_function_info_.scope =
NewFunctionScope(FunctionKind::kArrowFunction);
return factory()->NewEmptyParentheses(beg_pos);
}
Scope::Snapshot scope_snapshot(scope());
ArrowHeadParsingScope maybe_arrow(impl(), FunctionKind::kArrowFunction);
// Heuristically try to detect immediately called functions before
// seeing the call parentheses.
if (peek() == Token::FUNCTION ||
(peek() == Token::ASYNC && PeekAhead() == Token::FUNCTION)) {
function_state_->set_next_function_is_likely_called();
}
AcceptINScope scope(this, true);
ExpressionT expr = ParseExpressionCoverGrammar();
expr->mark_parenthesized();
Expect(Token::RPAREN);
if (peek() == Token::ARROW) {
next_arrow_function_info_.scope = maybe_arrow.ValidateAndCreateScope();
scope_snapshot.Reparent(next_arrow_function_info_.scope);
} else {
maybe_arrow.ValidateExpression();
}
return expr;
}
case Token::CLASS: {
Consume(Token::CLASS);
int class_token_pos = position();
IdentifierT name = impl()->NullIdentifier();
bool is_strict_reserved_name = false;
Scanner::Location class_name_location = Scanner::Location::invalid();
if (peek_any_identifier()) {
name = ParseAndClassifyIdentifier(Next());
class_name_location = scanner()->location();
is_strict_reserved_name =
Token::IsStrictReservedWord(scanner()->current_token());
}
return ParseClassLiteral(name, class_name_location,
is_strict_reserved_name, class_token_pos);
}
case Token::TEMPLATE_SPAN:
case Token::TEMPLATE_TAIL:
return ParseTemplateLiteral(impl()->NullExpression(), beg_pos, false);
case Token::MOD:
if (flags().allow_natives_syntax() || extension_ != nullptr) {
return ParseV8Intrinsic();
}
break;
default:
break;
}
ReportUnexpectedToken(Next());
return impl()->FailureExpression();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseExpression() {
ExpressionParsingScope expression_scope(impl());
AcceptINScope scope(this, true);
ExpressionT result = ParseExpressionCoverGrammar();
expression_scope.ValidateExpression();
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseAssignmentExpression() {
ExpressionParsingScope expression_scope(impl());
ExpressionT result = ParseAssignmentExpressionCoverGrammar();
expression_scope.ValidateExpression();
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseExpressionCoverGrammar() {
// Expression ::
// AssignmentExpression
// Expression ',' AssignmentExpression
ExpressionListT list(pointer_buffer());
ExpressionT expression;
AccumulationScope accumulation_scope(expression_scope());
int variable_index = 0;
while (true) {
if (V8_UNLIKELY(peek() == Token::ELLIPSIS)) {
return ParseArrowParametersWithRest(&list, &accumulation_scope,
variable_index);
}
int expr_pos = peek_position();
expression = ParseAssignmentExpressionCoverGrammar();
ClassifyArrowParameter(&accumulation_scope, expr_pos, expression);
list.Add(expression);
variable_index =
expression_scope()->SetInitializers(variable_index, peek_position());
if (!Check(Token::COMMA)) break;
if (peek() == Token::RPAREN && PeekAhead() == Token::ARROW) {
// a trailing comma is allowed at the end of an arrow parameter list
break;
}
// Pass on the 'set_next_function_is_likely_called' flag if we have
// several function literals separated by comma.
if (peek() == Token::FUNCTION &&
function_state_->previous_function_was_likely_called()) {
function_state_->set_next_function_is_likely_called();
}
}
// Return the single element if the list is empty. We need to do this because
// callers of this function care about the type of the result if there was
// only a single assignment expression. The preparser would lose this
// information otherwise.
if (list.length() == 1) return expression;
return impl()->ExpressionListToExpression(list);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseArrowParametersWithRest(
typename ParserBase<Impl>::ExpressionListT* list,
AccumulationScope* accumulation_scope, int seen_variables) {
Consume(Token::ELLIPSIS);
Scanner::Location ellipsis = scanner()->location();
int pattern_pos = peek_position();
ExpressionT pattern = ParseBindingPattern();
ClassifyArrowParameter(accumulation_scope, pattern_pos, pattern);
expression_scope()->RecordNonSimpleParameter();
if (V8_UNLIKELY(peek() == Token::ASSIGN)) {
ReportMessage(MessageTemplate::kRestDefaultInitializer);
return impl()->FailureExpression();
}
ExpressionT spread =
factory()->NewSpread(pattern, ellipsis.beg_pos, pattern_pos);
if (V8_UNLIKELY(peek() == Token::COMMA)) {
ReportMessage(MessageTemplate::kParamAfterRest);
return impl()->FailureExpression();
}
expression_scope()->SetInitializers(seen_variables, peek_position());
// 'x, y, ...z' in CoverParenthesizedExpressionAndArrowParameterList only
// as the formal parameters of'(x, y, ...z) => foo', and is not itself a
// valid expression.
if (peek() != Token::RPAREN || PeekAhead() != Token::ARROW) {
impl()->ReportUnexpectedTokenAt(ellipsis, Token::ELLIPSIS);
return impl()->FailureExpression();
}
list->Add(spread);
return impl()->ExpressionListToExpression(*list);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseArrayLiteral() {
// ArrayLiteral ::
// '[' Expression? (',' Expression?)* ']'
int pos = peek_position();
ExpressionListT values(pointer_buffer());
int first_spread_index = -1;
Consume(Token::LBRACK);
AccumulationScope accumulation_scope(expression_scope());
while (!Check(Token::RBRACK)) {
ExpressionT elem;
if (peek() == Token::COMMA) {
elem = factory()->NewTheHoleLiteral();
} else if (Check(Token::ELLIPSIS)) {
int start_pos = position();
int expr_pos = peek_position();
AcceptINScope scope(this, true);
ExpressionT argument =
ParsePossibleDestructuringSubPattern(&accumulation_scope);
elem = factory()->NewSpread(argument, start_pos, expr_pos);
if (first_spread_index < 0) {
first_spread_index = values.length();
}
if (argument->IsAssignment()) {
expression_scope()->RecordPatternError(
Scanner::Location(start_pos, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
}
if (peek() == Token::COMMA) {
expression_scope()->RecordPatternError(
Scanner::Location(start_pos, end_position()),
MessageTemplate::kElementAfterRest);
}
} else {
AcceptINScope scope(this, true);
elem = ParsePossibleDestructuringSubPattern(&accumulation_scope);
}
values.Add(elem);
if (peek() != Token::RBRACK) {
Expect(Token::COMMA);
if (elem->IsFailureExpression()) return elem;
}
}
return factory()->NewArrayLiteral(values, first_spread_index, pos);
}
template <class Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseProperty(
ParsePropertyInfo* prop_info) {
DCHECK_EQ(prop_info->kind, ParsePropertyKind::kNotSet);
DCHECK_EQ(prop_info->function_flags, ParseFunctionFlag::kIsNormal);
DCHECK(!prop_info->is_computed_name);
if (Check(Token::ASYNC)) {
Token::Value token = peek();
if ((token != Token::MUL && prop_info->ParsePropertyKindFromToken(token)) ||
scanner()->HasLineTerminatorBeforeNext()) {
prop_info->name = impl()->GetIdentifier();
impl()->PushLiteralName(prop_info->name);
return factory()->NewStringLiteral(prop_info->name, position());
}
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
impl()->ReportUnexpectedToken(Token::ESCAPED_KEYWORD);
}
prop_info->function_flags = ParseFunctionFlag::kIsAsync;
prop_info->kind = ParsePropertyKind::kMethod;
}
if (Check(Token::MUL)) {
prop_info->function_flags |= ParseFunctionFlag::kIsGenerator;
prop_info->kind = ParsePropertyKind::kMethod;
}
if (prop_info->kind == ParsePropertyKind::kNotSet &&
base::IsInRange(peek(), Token::GET, Token::SET)) {
Token::Value token = Next();
if (prop_info->ParsePropertyKindFromToken(peek())) {
prop_info->name = impl()->GetIdentifier();
impl()->PushLiteralName(prop_info->name);
return factory()->NewStringLiteral(prop_info->name, position());
}
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
impl()->ReportUnexpectedToken(Token::ESCAPED_KEYWORD);
}
if (token == Token::GET) {
prop_info->kind = ParsePropertyKind::kAccessorGetter;
} else if (token == Token::SET) {
prop_info->kind = ParsePropertyKind::kAccessorSetter;
}
}
int pos = peek_position();
// For non computed property names we normalize the name a bit:
//
// "12" -> 12
// 12.3 -> "12.3"
// 12.30 -> "12.3"
// identifier -> "identifier"
//
// This is important because we use the property name as a key in a hash
// table when we compute constant properties.
bool is_array_index;
uint32_t index;
switch (peek()) {
case Token::PRIVATE_NAME:
prop_info->is_private = true;
is_array_index = false;
Consume(Token::PRIVATE_NAME);
if (prop_info->kind == ParsePropertyKind::kNotSet) {
prop_info->ParsePropertyKindFromToken(peek());
}
prop_info->name = impl()->GetIdentifier();
if (V8_UNLIKELY(prop_info->position ==
PropertyPosition::kObjectLiteral)) {
ReportUnexpectedToken(Token::PRIVATE_NAME);
prop_info->kind = ParsePropertyKind::kNotSet;
return impl()->FailureExpression();
}
if (V8_UNLIKELY(!flags().allow_harmony_private_methods() &&
(IsAccessor(prop_info->kind) ||
prop_info->kind == ParsePropertyKind::kMethod))) {
ReportUnexpectedToken(Next());
prop_info->kind = ParsePropertyKind::kNotSet;
return impl()->FailureExpression();
}
break;
case Token::STRING:
Consume(Token::STRING);
prop_info->name = peek() == Token::COLON ? impl()->GetSymbol()
: impl()->GetIdentifier();
is_array_index = impl()->IsArrayIndex(prop_info->name, &index);
break;
case Token::SMI:
Consume(Token::SMI);
index = scanner()->smi_value();
is_array_index = true;
// Token::SMI were scanned from their canonical representation.
prop_info->name = impl()->GetSymbol();
break;
case Token::NUMBER: {
Consume(Token::NUMBER);
prop_info->name = impl()->GetNumberAsSymbol();
is_array_index = impl()->IsArrayIndex(prop_info->name, &index);
break;
}
case Token::BIGINT: {
Consume(Token::BIGINT);
prop_info->name = impl()->GetSymbol();
is_array_index = impl()->IsArrayIndex(prop_info->name, &index);
break;
}
case Token::LBRACK: {
prop_info->name = impl()->NullIdentifier();
prop_info->is_computed_name = true;
Consume(Token::LBRACK);
AcceptINScope scope(this, true);
ExpressionT expression = ParseAssignmentExpression();
Expect(Token::RBRACK);
if (prop_info->kind == ParsePropertyKind::kNotSet) {
prop_info->ParsePropertyKindFromToken(peek());
}
return expression;
}
case Token::ELLIPSIS:
if (prop_info->kind == ParsePropertyKind::kNotSet) {
prop_info->name = impl()->NullIdentifier();
Consume(Token::ELLIPSIS);
AcceptINScope scope(this, true);
int start_pos = peek_position();
ExpressionT expression =
ParsePossibleDestructuringSubPattern(prop_info->accumulation_scope);
prop_info->kind = ParsePropertyKind::kSpread;
if (!IsValidReferenceExpression(expression)) {
expression_scope()->RecordDeclarationError(
Scanner::Location(start_pos, end_position()),
MessageTemplate::kInvalidRestBindingPattern);
expression_scope()->RecordPatternError(
Scanner::Location(start_pos, end_position()),
MessageTemplate::kInvalidRestAssignmentPattern);
}
if (peek() != Token::RBRACE) {
expression_scope()->RecordPatternError(
scanner()->location(), MessageTemplate::kElementAfterRest);
}
return expression;
}
V8_FALLTHROUGH;
default:
prop_info->name = ParsePropertyName();
is_array_index = false;
break;
}
if (prop_info->kind == ParsePropertyKind::kNotSet) {
prop_info->ParsePropertyKindFromToken(peek());
}
impl()->PushLiteralName(prop_info->name);
return is_array_index ? factory()->NewNumberLiteral(index, pos)
: factory()->NewStringLiteral(prop_info->name, pos);
}
template <typename Impl>
typename ParserBase<Impl>::ClassLiteralPropertyT
ParserBase<Impl>::ParseClassPropertyDefinition(ClassInfo* class_info,
ParsePropertyInfo* prop_info,
bool has_extends) {
DCHECK_NOT_NULL(class_info);
DCHECK_EQ(prop_info->position, PropertyPosition::kClassLiteral);
Token::Value name_token = peek();
int property_beg_pos = scanner()->peek_location().beg_pos;
int name_token_position = property_beg_pos;
ExpressionT name_expression;
if (name_token == Token::STATIC) {
Consume(Token::STATIC);
name_token_position = scanner()->peek_location().beg_pos;
if (peek() == Token::LPAREN) {
prop_info->kind = ParsePropertyKind::kMethod;
// TODO(bakkot) specialize on 'static'
prop_info->name = impl()->GetIdentifier();
name_expression =
factory()->NewStringLiteral(prop_info->name, position());
} else if (peek() == Token::ASSIGN || peek() == Token::SEMICOLON ||
peek() == Token::RBRACE) {
// TODO(bakkot) specialize on 'static'
prop_info->name = impl()->GetIdentifier();
name_expression =
factory()->NewStringLiteral(prop_info->name, position());
} else {
prop_info->is_static = true;
name_expression = ParseProperty(prop_info);
}
} else {
name_expression = ParseProperty(prop_info);
}
if (!class_info->has_name_static_property && prop_info->is_static &&
impl()->IsName(prop_info->name)) {
class_info->has_name_static_property = true;
}
switch (prop_info->kind) {
case ParsePropertyKind::kAssign:
case ParsePropertyKind::kClassField:
case ParsePropertyKind::kShorthandOrClassField:
case ParsePropertyKind::kNotSet: { // This case is a name followed by a
// name or other property. Here we have
// to assume that's an uninitialized
// field followed by a linebreak
// followed by a property, with ASI
// adding the semicolon. If not, there
// will be a syntax error after parsing
// the first name as an uninitialized
// field.
prop_info->kind = ParsePropertyKind::kClassField;
DCHECK_IMPLIES(prop_info->is_computed_name, !prop_info->is_private);
if (!prop_info->is_computed_name) {
CheckClassFieldName(prop_info->name, prop_info->is_static);
}
ExpressionT initializer = ParseMemberInitializer(
class_info, property_beg_pos, prop_info->is_static);
ExpectSemicolon();
ClassLiteralPropertyT result = factory()->NewClassLiteralProperty(
name_expression, initializer, ClassLiteralProperty::FIELD,
prop_info->is_static, prop_info->is_computed_name,
prop_info->is_private);
impl()->SetFunctionNameFromPropertyName(result, prop_info->name);
return result;
}
case ParsePropertyKind::kMethod: {
// MethodDefinition
// PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
// '*' PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
// async PropertyName '(' StrictFormalParameters ')'
// '{' FunctionBody '}'
// async '*' PropertyName '(' StrictFormalParameters ')'
// '{' FunctionBody '}'
if (!prop_info->is_computed_name) {
CheckClassMethodName(prop_info->name, ParsePropertyKind::kMethod,
prop_info->function_flags, prop_info->is_static,
&class_info->has_seen_constructor);
}
FunctionKind kind = MethodKindFor(prop_info->function_flags);
if (!prop_info->is_static && impl()->IsConstructor(prop_info->name)) {
class_info->has_seen_constructor = true;
kind = has_extends ? FunctionKind::kDerivedConstructor
: FunctionKind::kBaseConstructor;
}
ExpressionT value = impl()->ParseFunctionLiteral(
prop_info->name, scanner()->location(), kSkipFunctionNameCheck, kind,
name_token_position, FunctionSyntaxKind::kAccessorOrMethod,
language_mode(), nullptr);
ClassLiteralPropertyT result = factory()->NewClassLiteralProperty(
name_expression, value, ClassLiteralProperty::METHOD,
prop_info->is_static, prop_info->is_computed_name,
prop_info->is_private);
impl()->SetFunctionNameFromPropertyName(result, prop_info->name);
return result;
}
case ParsePropertyKind::kAccessorGetter:
case ParsePropertyKind::kAccessorSetter: {
DCHECK_EQ(prop_info->function_flags, ParseFunctionFlag::kIsNormal);
bool is_get = prop_info->kind == ParsePropertyKind::kAccessorGetter;
if (!prop_info->is_computed_name) {
CheckClassMethodName(prop_info->name, prop_info->kind,
ParseFunctionFlag::kIsNormal, prop_info->is_static,
&class_info->has_seen_constructor);
// Make sure the name expression is a string since we need a Name for
// Runtime_DefineAccessorPropertyUnchecked and since we can determine
// this statically we can skip the extra runtime check.
name_expression = factory()->NewStringLiteral(
prop_info->name, name_expression->position());
}
FunctionKind kind = is_get ? FunctionKind::kGetterFunction
: FunctionKind::kSetterFunction;
FunctionLiteralT value = impl()->ParseFunctionLiteral(
prop_info->name, scanner()->location(), kSkipFunctionNameCheck, kind,
name_token_position, FunctionSyntaxKind::kAccessorOrMethod,
language_mode(), nullptr);
ClassLiteralProperty::Kind property_kind =
is_get ? ClassLiteralProperty::GETTER : ClassLiteralProperty::SETTER;
ClassLiteralPropertyT result = factory()->NewClassLiteralProperty(
name_expression, value, property_kind, prop_info->is_static,
prop_info->is_computed_name, prop_info->is_private);
const AstRawString* prefix =
is_get ? ast_value_factory()->get_space_string()
: ast_value_factory()->set_space_string();
impl()->SetFunctionNameFromPropertyName(result, prop_info->name, prefix);
return result;
}
case ParsePropertyKind::kValue:
case ParsePropertyKind::kShorthand:
case ParsePropertyKind::kSpread:
impl()->ReportUnexpectedTokenAt(
Scanner::Location(name_token_position, name_expression->position()),
name_token);
return impl()->NullLiteralProperty();
}
UNREACHABLE();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseMemberInitializer(
ClassInfo* class_info, int beg_pos, bool is_static) {
FunctionParsingScope body_parsing_scope(impl());
DeclarationScope* initializer_scope =
is_static ? class_info->static_fields_scope
: class_info->instance_members_scope;
if (initializer_scope == nullptr) {
initializer_scope =
NewFunctionScope(FunctionKind::kClassMembersInitializerFunction);
// TODO(gsathya): Make scopes be non contiguous.
initializer_scope->set_start_position(beg_pos);
initializer_scope->SetLanguageMode(LanguageMode::kStrict);
}
ExpressionT initializer;
if (Check(Token::ASSIGN)) {
FunctionState initializer_state(&function_state_, &scope_,
initializer_scope);
AcceptINScope scope(this, true);
initializer = ParseAssignmentExpression();
} else {
initializer = factory()->NewUndefinedLiteral(kNoSourcePosition);
}
initializer_scope->set_end_position(end_position());
if (is_static) {
class_info->static_fields_scope = initializer_scope;
class_info->has_static_class_fields = true;
} else {
class_info->instance_members_scope = initializer_scope;
class_info->has_instance_members = true;
}
return initializer;
}
template <typename Impl>
typename ParserBase<Impl>::ObjectLiteralPropertyT
ParserBase<Impl>::ParseObjectPropertyDefinition(ParsePropertyInfo* prop_info,
bool* has_seen_proto) {
DCHECK_EQ(prop_info->position, PropertyPosition::kObjectLiteral);
Token::Value name_token = peek();
Scanner::Location next_loc = scanner()->peek_location();
ExpressionT name_expression = ParseProperty(prop_info);
DCHECK_IMPLIES(name_token == Token::PRIVATE_NAME, has_error());
IdentifierT name = prop_info->name;
ParseFunctionFlags function_flags = prop_info->function_flags;
ParsePropertyKind kind = prop_info->kind;
switch (prop_info->kind) {
case ParsePropertyKind::kSpread:
DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
DCHECK(!prop_info->is_computed_name);
DCHECK_EQ(Token::ELLIPSIS, name_token);
prop_info->is_computed_name = true;
prop_info->is_rest = true;
return factory()->NewObjectLiteralProperty(
factory()->NewTheHoleLiteral(), name_expression,
ObjectLiteralProperty::SPREAD, true);
case ParsePropertyKind::kValue: {
DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
if (!prop_info->is_computed_name &&
scanner()->CurrentLiteralEquals("__proto__")) {
if (*has_seen_proto) {
expression_scope()->RecordExpressionError(
scanner()->location(), MessageTemplate::kDuplicateProto);
}
*has_seen_proto = true;
}
Consume(Token::COLON);
AcceptINScope scope(this, true);
ExpressionT value =
ParsePossibleDestructuringSubPattern(prop_info->accumulation_scope);
ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
name_expression, value, prop_info->is_computed_name);
impl()->SetFunctionNameFromPropertyName(result, name);
return result;
}
case ParsePropertyKind::kAssign:
case ParsePropertyKind::kShorthandOrClassField:
case ParsePropertyKind::kShorthand: {
// PropertyDefinition
// IdentifierReference
// CoverInitializedName
//
// CoverInitializedName
// IdentifierReference Initializer?
DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
if (!Token::IsValidIdentifier(
name_token, language_mode(), is_generator(),
flags().is_module() || is_async_function())) {
ReportUnexpectedToken(Next());
return impl()->NullLiteralProperty();
}
DCHECK(!prop_info->is_computed_name);
if (name_token == Token::AWAIT) {
DCHECK(!is_async_function());
expression_scope()->RecordAsyncArrowParametersError(
next_loc, MessageTemplate::kAwaitBindingIdentifier);
}
ExpressionT lhs =
impl()->ExpressionFromIdentifier(name, next_loc.beg_pos);
if (!IsAssignableIdentifier(lhs)) {
expression_scope()->RecordPatternError(
next_loc, MessageTemplate::kStrictEvalArguments);
}
ExpressionT value;
if (peek() == Token::ASSIGN) {
Consume(Token::ASSIGN);
{
AcceptINScope scope(this, true);
ExpressionT rhs = ParseAssignmentExpression();
value = factory()->NewAssignment(Token::ASSIGN, lhs, rhs,
kNoSourcePosition);
impl()->SetFunctionNameFromIdentifierRef(rhs, lhs);
}
expression_scope()->RecordExpressionError(
Scanner::Location(next_loc.beg_pos, end_position()),
MessageTemplate::kInvalidCoverInitializedName);
} else {
value = lhs;
}
ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
name_expression, value, ObjectLiteralProperty::COMPUTED, false);
impl()->SetFunctionNameFromPropertyName(result, name);
return result;
}
case ParsePropertyKind::kMethod: {
// MethodDefinition
// PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
// '*' PropertyName '(' StrictFormalParameters ')' '{' FunctionBody '}'
expression_scope()->RecordPatternError(
Scanner::Location(next_loc.beg_pos, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
FunctionKind kind = MethodKindFor(function_flags);
ExpressionT value = impl()->ParseFunctionLiteral(
name, scanner()->location(), kSkipFunctionNameCheck, kind,
next_loc.beg_pos, FunctionSyntaxKind::kAccessorOrMethod,
language_mode(), nullptr);
ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
name_expression, value, ObjectLiteralProperty::COMPUTED,
prop_info->is_computed_name);
impl()->SetFunctionNameFromPropertyName(result, name);
return result;
}
case ParsePropertyKind::kAccessorGetter:
case ParsePropertyKind::kAccessorSetter: {
DCHECK_EQ(function_flags, ParseFunctionFlag::kIsNormal);
bool is_get = kind == ParsePropertyKind::kAccessorGetter;
expression_scope()->RecordPatternError(
Scanner::Location(next_loc.beg_pos, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
if (!prop_info->is_computed_name) {
// Make sure the name expression is a string since we need a Name for
// Runtime_DefineAccessorPropertyUnchecked and since we can determine
// this statically we can skip the extra runtime check.
name_expression =
factory()->NewStringLiteral(name, name_expression->position());
}
FunctionKind kind = is_get ? FunctionKind::kGetterFunction
: FunctionKind::kSetterFunction;
FunctionLiteralT value = impl()->ParseFunctionLiteral(
name, scanner()->location(), kSkipFunctionNameCheck, kind,
next_loc.beg_pos, FunctionSyntaxKind::kAccessorOrMethod,
language_mode(), nullptr);
ObjectLiteralPropertyT result = factory()->NewObjectLiteralProperty(
name_expression, value,
is_get ? ObjectLiteralProperty::GETTER
: ObjectLiteralProperty::SETTER,
prop_info->is_computed_name);
const AstRawString* prefix =
is_get ? ast_value_factory()->get_space_string()
: ast_value_factory()->set_space_string();
impl()->SetFunctionNameFromPropertyName(result, name, prefix);
return result;
}
case ParsePropertyKind::kClassField:
case ParsePropertyKind::kNotSet:
ReportUnexpectedToken(Next());
return impl()->NullLiteralProperty();
}
UNREACHABLE();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseObjectLiteral() {
// ObjectLiteral ::
// '{' (PropertyDefinition (',' PropertyDefinition)* ','? )? '}'
int pos = peek_position();
ObjectPropertyListT properties(pointer_buffer());
int number_of_boilerplate_properties = 0;
bool has_computed_names = false;
bool has_rest_property = false;
bool has_seen_proto = false;
Consume(Token::LBRACE);
AccumulationScope accumulation_scope(expression_scope());
while (!Check(Token::RBRACE)) {
FuncNameInferrerState fni_state(&fni_);
ParsePropertyInfo prop_info(this, &accumulation_scope);
prop_info.position = PropertyPosition::kObjectLiteral;
ObjectLiteralPropertyT property =
ParseObjectPropertyDefinition(&prop_info, &has_seen_proto);
if (impl()->IsNull(property)) return impl()->FailureExpression();
if (prop_info.is_computed_name) {
has_computed_names = true;
}
if (prop_info.is_rest) {
has_rest_property = true;
}
if (impl()->IsBoilerplateProperty(property) && !has_computed_names) {
// Count CONSTANT or COMPUTED properties to maintain the enumeration
// order.
number_of_boilerplate_properties++;
}
properties.Add(property);
if (peek() != Token::RBRACE) {
Expect(Token::COMMA);
}
fni_.Infer();
}
// In pattern rewriter, we rewrite rest property to call out to a
// runtime function passing all the other properties as arguments to
// this runtime function. Here, we make sure that the number of
// properties is less than number of arguments allowed for a runtime
// call.
if (has_rest_property && properties.length() > Code::kMaxArguments) {
expression_scope()->RecordPatternError(Scanner::Location(pos, position()),
MessageTemplate::kTooManyArguments);
}
return impl()->InitializeObjectLiteral(factory()->NewObjectLiteral(
properties, number_of_boilerplate_properties, pos, has_rest_property));
}
template <typename Impl>
void ParserBase<Impl>::ParseArguments(
typename ParserBase<Impl>::ExpressionListT* args, bool* has_spread,
ParsingArrowHeadFlag maybe_arrow) {
// Arguments ::
// '(' (AssignmentExpression)*[','] ')'
*has_spread = false;
Consume(Token::LPAREN);
AccumulationScope accumulation_scope(expression_scope());
int variable_index = 0;
while (peek() != Token::RPAREN) {
int start_pos = peek_position();
bool is_spread = Check(Token::ELLIPSIS);
int expr_pos = peek_position();
AcceptINScope scope(this, true);
ExpressionT argument = ParseAssignmentExpressionCoverGrammar();
if (V8_UNLIKELY(maybe_arrow == kMaybeArrowHead)) {
ClassifyArrowParameter(&accumulation_scope, expr_pos, argument);
if (is_spread) {
expression_scope()->RecordNonSimpleParameter();
if (argument->IsAssignment()) {
expression_scope()->RecordAsyncArrowParametersError(
scanner()->location(), MessageTemplate::kRestDefaultInitializer);
}
if (peek() == Token::COMMA) {
expression_scope()->RecordAsyncArrowParametersError(
scanner()->peek_location(), MessageTemplate::kParamAfterRest);
}
}
}
if (is_spread) {
*has_spread = true;
argument = factory()->NewSpread(argument, start_pos, expr_pos);
}
args->Add(argument);
variable_index =
expression_scope()->SetInitializers(variable_index, peek_position());
if (!Check(Token::COMMA)) break;
}
if (args->length() > Code::kMaxArguments) {
ReportMessage(MessageTemplate::kTooManyArguments);
return;
}
Scanner::Location location = scanner_->location();
if (!Check(Token::RPAREN)) {
impl()->ReportMessageAt(location, MessageTemplate::kUnterminatedArgList);
}
}
// Precedence = 2
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseAssignmentExpressionCoverGrammar() {
// AssignmentExpression ::
// ConditionalExpression
// ArrowFunction
// YieldExpression
// LeftHandSideExpression AssignmentOperator AssignmentExpression
int lhs_beg_pos = peek_position();
if (peek() == Token::YIELD && is_generator()) {
return ParseYieldExpression();
}
FuncNameInferrerState fni_state(&fni_);
DCHECK_IMPLIES(!has_error(), next_arrow_function_info_.HasInitialState());
ExpressionT expression = ParseConditionalExpression();
Token::Value op = peek();
if (!Token::IsArrowOrAssignmentOp(op)) return expression;
if (Token::IsLogicalAssignmentOp(op) &&
!flags().allow_harmony_logical_assignment()) {
return expression;
}
// Arrow functions.
if (V8_UNLIKELY(op == Token::ARROW)) {
Scanner::Location loc(lhs_beg_pos, end_position());
if (!impl()->IsIdentifier(expression) && !expression->is_parenthesized()) {
impl()->ReportMessageAt(
Scanner::Location(expression->position(), position()),
MessageTemplate::kMalformedArrowFunParamList);
return impl()->FailureExpression();
}
DeclarationScope* scope = next_arrow_function_info_.scope;
scope->set_start_position(lhs_beg_pos);
FormalParametersT parameters(scope);
parameters.set_strict_parameter_error(
next_arrow_function_info_.strict_parameter_error_location,
next_arrow_function_info_.strict_parameter_error_message);
parameters.is_simple = scope->has_simple_parameters();
next_arrow_function_info_.Reset();
impl()->DeclareArrowFunctionFormalParameters(&parameters, expression, loc);
expression = ParseArrowFunctionLiteral(parameters);
return expression;
}
if (V8_LIKELY(impl()->IsAssignableIdentifier(expression))) {
if (expression->is_parenthesized()) {
expression_scope()->RecordDeclarationError(
Scanner::Location(lhs_beg_pos, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
}
expression_scope()->MarkIdentifierAsAssigned();
} else if (expression->IsProperty()) {
expression_scope()->RecordDeclarationError(
Scanner::Location(lhs_beg_pos, end_position()),
MessageTemplate::kInvalidPropertyBindingPattern);
expression_scope()->ValidateAsExpression();
} else if (expression->IsPattern() && op == Token::ASSIGN) {
// Destructuring assignmment.
if (expression->is_parenthesized()) {
Scanner::Location loc(lhs_beg_pos, end_position());
if (expression_scope()->IsCertainlyDeclaration()) {
impl()->ReportMessageAt(loc,
MessageTemplate::kInvalidDestructuringTarget);
} else {
// Syntax Error if LHS is neither object literal nor an array literal
// (Parenthesized literals are
// CoverParenthesizedExpressionAndArrowParameterList).
// #sec-assignment-operators-static-semantics-early-errors
impl()->ReportMessageAt(loc, MessageTemplate::kInvalidLhsInAssignment);
}
}
expression_scope()->ValidateAsPattern(expression, lhs_beg_pos,
end_position());
} else {
DCHECK(!IsValidReferenceExpression(expression));
// For web compatibility reasons, throw early errors only for logical
// assignment, not for regular assignment.
const bool early_error = Token::IsLogicalAssignmentOp(op);
expression = RewriteInvalidReferenceExpression(
expression, lhs_beg_pos, end_position(),
MessageTemplate::kInvalidLhsInAssignment, early_error);
}
Consume(op);
int op_position = position();
ExpressionT right = ParseAssignmentExpression();
// Anonymous function name inference applies to =, ||=, &&=, and ??=.
if (op == Token::ASSIGN || Token::IsLogicalAssignmentOp(op)) {
impl()->CheckAssigningFunctionLiteralToProperty(expression, right);
// Check if the right hand side is a call to avoid inferring a
// name if we're dealing with "a = function(){...}();"-like
// expression.
if (right->IsCall() || right->IsCallNew()) {
fni_.RemoveLastFunction();
} else {
fni_.Infer();
}
impl()->SetFunctionNameFromIdentifierRef(right, expression);
} else {
fni_.RemoveLastFunction();
}
if (op == Token::ASSIGN) {
// We try to estimate the set of properties set by constructors. We define a
// new property whenever there is an assignment to a property of 'this'. We
// should probably only add properties if we haven't seen them before.
// Otherwise we'll probably overestimate the number of properties.
if (impl()->IsThisProperty(expression)) function_state_->AddProperty();
} else {
// Only initializers (i.e. no compound assignments) are allowed in patterns.
expression_scope()->RecordPatternError(
Scanner::Location(lhs_beg_pos, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
}
return factory()->NewAssignment(op, expression, right, op_position);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseYieldExpression() {
// YieldExpression ::
// 'yield' ([no line terminator] '*'? AssignmentExpression)?
int pos = peek_position();
expression_scope()->RecordParameterInitializerError(
scanner()->peek_location(), MessageTemplate::kYieldInParameter);
Consume(Token::YIELD);
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
impl()->ReportUnexpectedToken(Token::ESCAPED_KEYWORD);
}
CheckStackOverflow();
// The following initialization is necessary.
ExpressionT expression = impl()->NullExpression();
bool delegating = false; // yield*
if (!scanner()->HasLineTerminatorBeforeNext()) {
if (Check(Token::MUL)) delegating = true;
switch (peek()) {
case Token::EOS:
case Token::SEMICOLON:
case Token::RBRACE:
case Token::RBRACK:
case Token::RPAREN:
case Token::COLON:
case Token::COMMA:
case Token::IN:
// The above set of tokens is the complete set of tokens that can appear
// after an AssignmentExpression, and none of them can start an
// AssignmentExpression. This allows us to avoid looking for an RHS for
// a regular yield, given only one look-ahead token.
if (!delegating) break;
// Delegating yields require an RHS; fall through.
V8_FALLTHROUGH;
default:
expression = ParseAssignmentExpressionCoverGrammar();
break;
}
}
if (delegating) {
ExpressionT yieldstar = factory()->NewYieldStar(expression, pos);
impl()->RecordSuspendSourceRange(yieldstar, PositionAfterSemicolon());
function_state_->AddSuspend();
if (IsAsyncGeneratorFunction(function_state_->kind())) {
// return, iterator_close and delegated_iterator_output suspend ids.
function_state_->AddSuspend();
function_state_->AddSuspend();
function_state_->AddSuspend();
}
return yieldstar;
}
// Hackily disambiguate o from o.next and o [Symbol.iterator]().
// TODO(verwaest): Come up with a better solution.
ExpressionT yield =
factory()->NewYield(expression, pos, Suspend::kOnExceptionThrow);
impl()->RecordSuspendSourceRange(yield, PositionAfterSemicolon());
function_state_->AddSuspend();
return yield;
}
// Precedence = 3
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseConditionalExpression() {
// ConditionalExpression ::
// LogicalExpression
// LogicalExpression '?' AssignmentExpression ':' AssignmentExpression
//
int pos = peek_position();
ExpressionT expression = ParseLogicalExpression();
return peek() == Token::CONDITIONAL
? ParseConditionalContinuation(expression, pos)
: expression;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseLogicalExpression() {
// LogicalExpression ::
// LogicalORExpression
// CoalesceExpression
// Both LogicalORExpression and CoalesceExpression start with BitwiseOR.
// Parse for binary expressions >= 6 (BitwiseOR);
ExpressionT expression = ParseBinaryExpression(6);
if (peek() == Token::AND || peek() == Token::OR) {
// LogicalORExpression, pickup parsing where we left off.
int prec1 = Token::Precedence(peek(), accept_IN_);
expression = ParseBinaryContinuation(expression, 4, prec1);
} else if (V8_UNLIKELY(peek() == Token::NULLISH)) {
expression = ParseCoalesceExpression(expression);
}
return expression;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseCoalesceExpression(ExpressionT expression) {
// CoalesceExpression ::
// CoalesceExpressionHead ?? BitwiseORExpression
//
// CoalesceExpressionHead ::
// CoalesceExpression
// BitwiseORExpression
// We create a binary operation for the first nullish, otherwise collapse
// into an nary expresion.
bool first_nullish = true;
while (peek() == Token::NULLISH) {
SourceRange right_range;
SourceRangeScope right_range_scope(scanner(), &right_range);
Consume(Token::NULLISH);
int pos = peek_position();
// Parse BitwiseOR or higher.
ExpressionT y = ParseBinaryExpression(6);
if (first_nullish) {
expression =
factory()->NewBinaryOperation(Token::NULLISH, expression, y, pos);
impl()->RecordBinaryOperationSourceRange(expression, right_range);
first_nullish = false;
} else {
impl()->CollapseNaryExpression(&expression, y, Token::NULLISH, pos,
right_range);
}
}
return expression;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseConditionalContinuation(ExpressionT expression,
int pos) {
SourceRange then_range, else_range;
ExpressionT left;
{
SourceRangeScope range_scope(scanner(), &then_range);
Consume(Token::CONDITIONAL);
// In parsing the first assignment expression in conditional
// expressions we always accept the 'in' keyword; see ECMA-262,
// section 11.12, page 58.
AcceptINScope scope(this, true);
left = ParseAssignmentExpression();
}
ExpressionT right;
{
SourceRangeScope range_scope(scanner(), &else_range);
Expect(Token::COLON);
right = ParseAssignmentExpression();
}
ExpressionT expr = factory()->NewConditional(expression, left, right, pos);
impl()->RecordConditionalSourceRange(expr, then_range, else_range);
return expr;
}
// Precedence >= 4
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseBinaryContinuation(ExpressionT x, int prec, int prec1) {
do {
// prec1 >= 4
while (Token::Precedence(peek(), accept_IN_) == prec1) {
SourceRange right_range;
int pos = peek_position();
ExpressionT y;
Token::Value op;
{
SourceRangeScope right_range_scope(scanner(), &right_range);
op = Next();
const bool is_right_associative = op == Token::EXP;
const int next_prec = is_right_associative ? prec1 : prec1 + 1;
y = ParseBinaryExpression(next_prec);
}
// For now we distinguish between comparisons and other binary
// operations. (We could combine the two and get rid of this
// code and AST node eventually.)
if (Token::IsCompareOp(op)) {
// We have a comparison.
Token::Value cmp = op;
switch (op) {
case Token::NE: cmp = Token::EQ; break;
case Token::NE_STRICT: cmp = Token::EQ_STRICT; break;
default: break;
}
x = factory()->NewCompareOperation(cmp, x, y, pos);
if (cmp != op) {
// The comparison was negated - add a NOT.
x = factory()->NewUnaryOperation(Token::NOT, x, pos);
}
} else if (!impl()->ShortcutNumericLiteralBinaryExpression(&x, y, op,
pos) &&
!impl()->CollapseNaryExpression(&x, y, op, pos, right_range)) {
// We have a "normal" binary operation.
x = factory()->NewBinaryOperation(op, x, y, pos);
if (op == Token::OR || op == Token::AND) {
impl()->RecordBinaryOperationSourceRange(x, right_range);
}
}
}
--prec1;
} while (prec1 >= prec);
return x;
}
// Precedence >= 4
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseBinaryExpression(
int prec) {
DCHECK_GE(prec, 4);
ExpressionT x = ParseUnaryExpression();
int prec1 = Token::Precedence(peek(), accept_IN_);
if (prec1 >= prec) {
return ParseBinaryContinuation(x, prec, prec1);
}
return x;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseUnaryOrPrefixExpression() {
Token::Value op = Next();
int pos = position();
// Assume "! function ..." indicates the function is likely to be called.
if (op == Token::NOT && peek() == Token::FUNCTION) {
function_state_->set_next_function_is_likely_called();
}
CheckStackOverflow();
int expression_position = peek_position();
ExpressionT expression = ParseUnaryExpression();
if (Token::IsUnaryOp(op)) {
if (op == Token::DELETE) {
if (impl()->IsIdentifier(expression) && is_strict(language_mode())) {
// "delete identifier" is a syntax error in strict mode.
ReportMessage(MessageTemplate::kStrictDelete);
return impl()->FailureExpression();
}
if (impl()->IsPrivateReference(expression)) {
ReportMessage(MessageTemplate::kDeletePrivateField);
return impl()->FailureExpression();
}
}
if (peek() == Token::EXP) {
impl()->ReportMessageAt(
Scanner::Location(pos, peek_end_position()),
MessageTemplate::kUnexpectedTokenUnaryExponentiation);
return impl()->FailureExpression();
}
// Allow the parser's implementation to rewrite the expression.
return impl()->BuildUnaryExpression(expression, op, pos);
}
DCHECK(Token::IsCountOp(op));
if (V8_LIKELY(IsValidReferenceExpression(expression))) {
if (impl()->IsIdentifier(expression)) {
expression_scope()->MarkIdentifierAsAssigned();
}
} else {
const bool early_error = false;
expression = RewriteInvalidReferenceExpression(
expression, expression_position, end_position(),
MessageTemplate::kInvalidLhsInPrefixOp, early_error);
}
return factory()->NewCountOperation(op, true /* prefix */, expression,
position());
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseAwaitExpression() {
expression_scope()->RecordParameterInitializerError(
scanner()->peek_location(),
MessageTemplate::kAwaitExpressionFormalParameter);
int await_pos = peek_position();
Consume(Token::AWAIT);
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
impl()->ReportUnexpectedToken(Token::ESCAPED_KEYWORD);
}
CheckStackOverflow();
ExpressionT value = ParseUnaryExpression();
ExpressionT expr = factory()->NewAwait(value, await_pos);
function_state_->AddSuspend();
impl()->RecordSuspendSourceRange(expr, PositionAfterSemicolon());
return expr;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseUnaryExpression() {
// UnaryExpression ::
// PostfixExpression
// 'delete' UnaryExpression
// 'void' UnaryExpression
// 'typeof' UnaryExpression
// '++' UnaryExpression
// '--' UnaryExpression
// '+' UnaryExpression
// '-' UnaryExpression
// '~' UnaryExpression
// '!' UnaryExpression
// [+Await] AwaitExpression[?Yield]
Token::Value op = peek();
if (Token::IsUnaryOrCountOp(op)) return ParseUnaryOrPrefixExpression();
if (is_await_allowed() && op == Token::AWAIT) {
return ParseAwaitExpression();
}
return ParsePostfixExpression();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParsePostfixExpression() {
// PostfixExpression ::
// LeftHandSideExpression ('++' | '--')?
int lhs_beg_pos = peek_position();
ExpressionT expression = ParseLeftHandSideExpression();
if (V8_LIKELY(!Token::IsCountOp(peek()) ||
scanner()->HasLineTerminatorBeforeNext())) {
return expression;
}
return ParsePostfixContinuation(expression, lhs_beg_pos);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParsePostfixContinuation(ExpressionT expression,
int lhs_beg_pos) {
if (V8_UNLIKELY(!IsValidReferenceExpression(expression))) {
const bool early_error = false;
expression = RewriteInvalidReferenceExpression(
expression, lhs_beg_pos, end_position(),
MessageTemplate::kInvalidLhsInPostfixOp, early_error);
}
if (impl()->IsIdentifier(expression)) {
expression_scope()->MarkIdentifierAsAssigned();
}
Token::Value next = Next();
return factory()->NewCountOperation(next, false /* postfix */, expression,
position());
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseLeftHandSideExpression() {
// LeftHandSideExpression ::
// (NewExpression | MemberExpression) ...
ExpressionT result = ParseMemberExpression();
if (!Token::IsPropertyOrCall(peek())) return result;
return ParseLeftHandSideContinuation(result);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseLeftHandSideContinuation(ExpressionT result) {
DCHECK(Token::IsPropertyOrCall(peek()));
if (V8_UNLIKELY(peek() == Token::LPAREN && impl()->IsIdentifier(result) &&
scanner()->current_token() == Token::ASYNC &&
!scanner()->HasLineTerminatorBeforeNext() &&
!scanner()->literal_contains_escapes())) {
DCHECK(impl()->IsAsync(impl()->AsIdentifier(result)));
int pos = position();
ArrowHeadParsingScope maybe_arrow(impl(),
FunctionKind::kAsyncArrowFunction);
Scope::Snapshot scope_snapshot(scope());
ExpressionListT args(pointer_buffer());
bool has_spread;
ParseArguments(&args, &has_spread, kMaybeArrowHead);
if (V8_LIKELY(peek() == Token::ARROW)) {
fni_.RemoveAsyncKeywordFromEnd();
next_arrow_function_info_.scope = maybe_arrow.ValidateAndCreateScope();
scope_snapshot.Reparent(next_arrow_function_info_.scope);
// async () => ...
if (!args.length()) return factory()->NewEmptyParentheses(pos);
// async ( Arguments ) => ...
ExpressionT result = impl()->ExpressionListToExpression(args);
result->mark_parenthesized();
return result;
}
if (has_spread) {
result = impl()->SpreadCall(result, args, pos, Call::NOT_EVAL, false);
} else {
result = factory()->NewCall(result, args, pos, Call::NOT_EVAL);
}
maybe_arrow.ValidateExpression();
fni_.RemoveLastFunction();
if (!Token::IsPropertyOrCall(peek())) return result;
}
bool optional_chaining = false;
bool is_optional = false;
do {
switch (peek()) {
case Token::QUESTION_PERIOD: {
if (is_optional) {
ReportUnexpectedToken(peek());
return impl()->FailureExpression();
}
Consume(Token::QUESTION_PERIOD);
is_optional = true;
optional_chaining = true;
continue;
}
/* Property */
case Token::LBRACK: {
Consume(Token::LBRACK);
int pos = position();
AcceptINScope scope(this, true);
ExpressionT index = ParseExpressionCoverGrammar();
result = factory()->NewProperty(result, index, pos, is_optional);
Expect(Token::RBRACK);
break;
}
/* Property */
case Token::PERIOD: {
if (is_optional) {
ReportUnexpectedToken(Next());
return impl()->FailureExpression();
}
Consume(Token::PERIOD);
int pos = position();
ExpressionT key = ParsePropertyOrPrivatePropertyName();
result = factory()->NewProperty(result, key, pos, is_optional);
break;
}
/* Call */
case Token::LPAREN: {
int pos;
if (Token::IsCallable(scanner()->current_token())) {
// For call of an identifier we want to report position of
// the identifier as position of the call in the stack trace.
pos = position();
} else {
// For other kinds of calls we record position of the parenthesis as
// position of the call. Note that this is extremely important for
// expressions of the form function(){...}() for which call position
// should not point to the closing brace otherwise it will intersect
// with positions recorded for function literal and confuse debugger.
pos = peek_position();
// Also the trailing parenthesis are a hint that the function will
// be called immediately. If we happen to have parsed a preceding
// function literal eagerly, we can also compile it eagerly.
if (result->IsFunctionLiteral()) {
result->AsFunctionLiteral()->SetShouldEagerCompile();
if (scope()->is_script_scope()) {
// A non-top-level iife is likely to be executed multiple times
// and so shouldn`t be optimized as one-shot.
result->AsFunctionLiteral()->mark_as_oneshot_iife();
}
}
}
bool has_spread;
ExpressionListT args(pointer_buffer());
ParseArguments(&args, &has_spread);
// Keep track of eval() calls since they disable all local variable
// optimizations.
// The calls that need special treatment are the
// direct eval calls. These calls are all of the form eval(...), with
// no explicit receiver.
// These calls are marked as potentially direct eval calls. Whether
// they are actually direct calls to eval is determined at run time.
Call::PossiblyEval is_possibly_eval =
CheckPossibleEvalCall(result, is_optional, scope());
if (has_spread) {
result = impl()->SpreadCall(result, args, pos, is_possibly_eval,
is_optional);
} else {
result = factory()->NewCall(result, args, pos, is_possibly_eval,
is_optional);
}
fni_.RemoveLastFunction();
break;
}
default:
/* Optional Property */
if (is_optional) {
DCHECK_EQ(scanner()->current_token(), Token::QUESTION_PERIOD);
int pos = position();
ExpressionT key = ParsePropertyOrPrivatePropertyName();
result = factory()->NewProperty(result, key, pos, is_optional);
break;
}
if (optional_chaining) {
impl()->ReportMessageAt(scanner()->peek_location(),
MessageTemplate::kOptionalChainingNoTemplate);
return impl()->FailureExpression();
}
/* Tagged Template */
DCHECK(Token::IsTemplate(peek()));
result = ParseTemplateLiteral(result, position(), true);
break;
}
is_optional = false;
} while (is_optional || Token::IsPropertyOrCall(peek()));
if (optional_chaining) return factory()->NewOptionalChain(result);
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseMemberWithPresentNewPrefixesExpression() {
// NewExpression ::
// ('new')+ MemberExpression
//
// NewTarget ::
// 'new' '.' 'target'
// The grammar for new expressions is pretty warped. We can have several 'new'
// keywords following each other, and then a MemberExpression. When we see '('
// after the MemberExpression, it's associated with the rightmost unassociated
// 'new' to create a NewExpression with arguments. However, a NewExpression
// can also occur without arguments.
// Examples of new expression:
// new foo.bar().baz means (new (foo.bar)()).baz
// new foo()() means (new foo())()
// new new foo()() means (new (new foo())())
// new new foo means new (new foo)
// new new foo() means new (new foo())
// new new foo().bar().baz means (new (new foo()).bar()).baz
Consume(Token::NEW);
int new_pos = position();
ExpressionT result;
CheckStackOverflow();
if (peek() == Token::SUPER) {
const bool is_new = true;
result = ParseSuperExpression(is_new);
} else if (peek() == Token::IMPORT && PeekAhead() == Token::LPAREN) {
impl()->ReportMessageAt(scanner()->peek_location(),
MessageTemplate::kImportCallNotNewExpression);
return impl()->FailureExpression();
} else if (peek() == Token::PERIOD) {
result = ParseNewTargetExpression();
return ParseMemberExpressionContinuation(result);
} else {
result = ParseMemberExpression();
}
if (peek() == Token::LPAREN) {
// NewExpression with arguments.
{
ExpressionListT args(pointer_buffer());
bool has_spread;
ParseArguments(&args, &has_spread);
if (has_spread) {
result = impl()->SpreadCallNew(result, args, new_pos);
} else {
result = factory()->NewCallNew(result, args, new_pos);
}
}
// The expression can still continue with . or [ after the arguments.
return ParseMemberExpressionContinuation(result);
}
if (peek() == Token::QUESTION_PERIOD) {
impl()->ReportMessageAt(scanner()->peek_location(),
MessageTemplate::kOptionalChainingNoNew);
return impl()->FailureExpression();
}
// NewExpression without arguments.
ExpressionListT args(pointer_buffer());
return factory()->NewCallNew(result, args, new_pos);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseFunctionExpression() {
Consume(Token::FUNCTION);
int function_token_position = position();
FunctionKind function_kind = Check(Token::MUL)
? FunctionKind::kGeneratorFunction
: FunctionKind::kNormalFunction;
IdentifierT name = impl()->NullIdentifier();
bool is_strict_reserved_name = Token::IsStrictReservedWord(peek());
Scanner::Location function_name_location = Scanner::Location::invalid();
FunctionSyntaxKind function_syntax_kind =
FunctionSyntaxKind::kAnonymousExpression;
if (impl()->ParsingDynamicFunctionDeclaration()) {
// We don't want dynamic functions to actually declare their name
// "anonymous". We just want that name in the toString().
Consume(Token::IDENTIFIER);
DCHECK_IMPLIES(!has_error(),
scanner()->CurrentSymbol(ast_value_factory()) ==
ast_value_factory()->anonymous_string());
} else if (peek_any_identifier()) {
name = ParseIdentifier(function_kind);
function_name_location = scanner()->location();
function_syntax_kind = FunctionSyntaxKind::kNamedExpression;
}
FunctionLiteralT result = impl()->ParseFunctionLiteral(
name, function_name_location,
is_strict_reserved_name ? kFunctionNameIsStrictReserved
: kFunctionNameValidityUnknown,
function_kind, function_token_position, function_syntax_kind,
language_mode(), nullptr);
// TODO(verwaest): FailureFunctionLiteral?
if (impl()->IsNull(result)) return impl()->FailureExpression();
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseMemberExpression() {
// MemberExpression ::
// (PrimaryExpression | FunctionLiteral | ClassLiteral)
// ('[' Expression ']' | '.' Identifier | Arguments | TemplateLiteral)*
//
// CallExpression ::
// (SuperCall | ImportCall)
// ('[' Expression ']' | '.' Identifier | Arguments | TemplateLiteral)*
//
// The '[' Expression ']' and '.' Identifier parts are parsed by
// ParseMemberExpressionContinuation, and everything preceeding it is merged
// into ParsePrimaryExpression.
// Parse the initial primary or function expression.
ExpressionT result = ParsePrimaryExpression();
return ParseMemberExpressionContinuation(result);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseImportExpressions() {
Consume(Token::IMPORT);
int pos = position();
if (Check(Token::PERIOD)) {
ExpectContextualKeyword(ast_value_factory()->meta_string(), "import.meta",
pos);
if (!flags().is_module()) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kImportMetaOutsideModule);
return impl()->FailureExpression();
}
return impl()->ImportMetaExpression(pos);
}
if (V8_UNLIKELY(peek() != Token::LPAREN)) {
if (!flags().is_module()) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kImportOutsideModule);
} else {
ReportUnexpectedToken(Next());
}
return impl()->FailureExpression();
}
Consume(Token::LPAREN);
if (peek() == Token::RPAREN) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kImportMissingSpecifier);
return impl()->FailureExpression();
}
AcceptINScope scope(this, true);
ExpressionT arg = ParseAssignmentExpressionCoverGrammar();
Expect(Token::RPAREN);
return factory()->NewImportCallExpression(arg, pos);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseSuperExpression(
bool is_new) {
Consume(Token::SUPER);
int pos = position();
DeclarationScope* scope = GetReceiverScope();
FunctionKind kind = scope->function_kind();
if (IsConciseMethod(kind) || IsAccessorFunction(kind) ||
IsClassConstructor(kind)) {
if (Token::IsProperty(peek())) {
if (peek() == Token::PERIOD && PeekAhead() == Token::PRIVATE_NAME) {
Consume(Token::PERIOD);
Consume(Token::PRIVATE_NAME);
impl()->ReportMessage(MessageTemplate::kUnexpectedPrivateField);
return impl()->FailureExpression();
}
if (peek() == Token::QUESTION_PERIOD) {
Consume(Token::QUESTION_PERIOD);
impl()->ReportMessage(MessageTemplate::kOptionalChainingNoSuper);
return impl()->FailureExpression();
}
scope->RecordSuperPropertyUsage();
UseThis();
return impl()->NewSuperPropertyReference(pos);
}
// new super() is never allowed.
// super() is only allowed in derived constructor
if (!is_new && peek() == Token::LPAREN && IsDerivedConstructor(kind)) {
// TODO(rossberg): This might not be the correct FunctionState for the
// method here.
expression_scope()->RecordThisUse();
UseThis();
return impl()->NewSuperCallReference(pos);
}
}
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kUnexpectedSuper);
return impl()->FailureExpression();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseNewTargetExpression() {
int pos = position();
Consume(Token::PERIOD);
ExpectContextualKeyword(ast_value_factory()->target_string(), "new.target",
pos);
if (!GetReceiverScope()->is_function_scope()) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kUnexpectedNewTarget);
return impl()->FailureExpression();
}
return impl()->NewTargetExpression(pos);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::DoParseMemberExpressionContinuation(ExpressionT expression) {
DCHECK(Token::IsMember(peek()));
// Parses this part of MemberExpression:
// ('[' Expression ']' | '.' Identifier | TemplateLiteral)*
do {
switch (peek()) {
case Token::LBRACK: {
Consume(Token::LBRACK);
int pos = position();
AcceptINScope scope(this, true);
ExpressionT index = ParseExpressionCoverGrammar();
expression = factory()->NewProperty(expression, index, pos);
impl()->PushPropertyName(index);
Expect(Token::RBRACK);
break;
}
case Token::PERIOD: {
Consume(Token::PERIOD);
int pos = peek_position();
ExpressionT key = ParsePropertyOrPrivatePropertyName();
expression = factory()->NewProperty(expression, key, pos);
break;
}
default: {
DCHECK(Token::IsTemplate(peek()));
int pos;
if (scanner()->current_token() == Token::IDENTIFIER) {
pos = position();
} else {
pos = peek_position();
if (expression->IsFunctionLiteral()) {
// If the tag function looks like an IIFE, set_parenthesized() to
// force eager compilation.
expression->AsFunctionLiteral()->SetShouldEagerCompile();
}
}
expression = ParseTemplateLiteral(expression, pos, true);
break;
}
}
} while (Token::IsMember(peek()));
return expression;
}
template <typename Impl>
void ParserBase<Impl>::ParseFormalParameter(FormalParametersT* parameters) {
// FormalParameter[Yield,GeneratorParameter] :
// BindingElement[?Yield, ?GeneratorParameter]
FuncNameInferrerState fni_state(&fni_);
int pos = peek_position();
auto declaration_it = scope()->declarations()->end();
ExpressionT pattern = ParseBindingPattern();
if (impl()->IsIdentifier(pattern)) {
ClassifyParameter(impl()->AsIdentifier(pattern), pos, end_position());
} else {
parameters->is_simple = false;
}
ExpressionT initializer = impl()->NullExpression();
if (Check(Token::ASSIGN)) {
parameters->is_simple = false;
if (parameters->has_rest) {
ReportMessage(MessageTemplate::kRestDefaultInitializer);
return;
}
AcceptINScope accept_in_scope(this, true);
initializer = ParseAssignmentExpression();
impl()->SetFunctionNameFromIdentifierRef(initializer, pattern);
}
auto declaration_end = scope()->declarations()->end();
int initializer_end = end_position();
for (; declaration_it != declaration_end; ++declaration_it) {
Variable* var = declaration_it->var();
// The first time a variable is initialized (i.e. when the initializer
// position is unset), clear its maybe_assigned flag as it is not a true
// assignment. Since this is done directly on the Variable objects, it has
// no effect on VariableProxy objects appearing on the left-hand side of
// true assignments, so x will be still be marked as maybe_assigned for:
// (x = 1, y = (x = 2)) => {}
// and even:
// (x = (x = 2)) => {}.
if (var->initializer_position() == kNoSourcePosition)
var->clear_maybe_assigned();
var->set_initializer_position(initializer_end);
}
impl()->AddFormalParameter(parameters, pattern, initializer, end_position(),
parameters->has_rest);
}
template <typename Impl>
void ParserBase<Impl>::ParseFormalParameterList(FormalParametersT* parameters) {
// FormalParameters[Yield] :
// [empty]
// FunctionRestParameter[?Yield]
// FormalParameterList[?Yield]
// FormalParameterList[?Yield] ,
// FormalParameterList[?Yield] , FunctionRestParameter[?Yield]
//
// FormalParameterList[Yield] :
// FormalParameter[?Yield]
// FormalParameterList[?Yield] , FormalParameter[?Yield]
ParameterParsingScope scope(impl(), parameters);
DCHECK_EQ(0, parameters->arity);
if (peek() != Token::RPAREN) {
while (true) {
// Add one since we're going to be adding a parameter.
if (parameters->arity + 1 > Code::kMaxArguments) {
ReportMessage(MessageTemplate::kTooManyParameters);
return;
}
parameters->has_rest = Check(Token::ELLIPSIS);
ParseFormalParameter(parameters);
if (parameters->has_rest) {
parameters->is_simple = false;
if (peek() == Token::COMMA) {
impl()->ReportMessageAt(scanner()->peek_location(),
MessageTemplate::kParamAfterRest);
return;
}
break;
}
if (!Check(Token::COMMA)) break;
if (peek() == Token::RPAREN) {
// allow the trailing comma
break;
}
}
}
impl()->DeclareFormalParameters(parameters);
}
template <typename Impl>
void ParserBase<Impl>::ParseVariableDeclarations(
VariableDeclarationContext var_context,
DeclarationParsingResult* parsing_result,
ZonePtrList<const AstRawString>* names) {
// VariableDeclarations ::
// ('var' | 'const' | 'let') (Identifier ('=' AssignmentExpression)?)+[',']
//
// ES6:
// FIXME(marja, nikolaos): Add an up-to-date comment about ES6 variable
// declaration syntax.
DCHECK_NOT_NULL(parsing_result);
parsing_result->descriptor.kind = NORMAL_VARIABLE;
parsing_result->descriptor.declaration_pos = peek_position();
parsing_result->descriptor.initialization_pos = peek_position();
switch (peek()) {
case Token::VAR:
parsing_result->descriptor.mode = VariableMode::kVar;
Consume(Token::VAR);
break;
case Token::CONST:
Consume(Token::CONST);
DCHECK_NE(var_context, kStatement);
parsing_result->descriptor.mode = VariableMode::kConst;
break;
case Token::LET:
Consume(Token::LET);
DCHECK_NE(var_context, kStatement);
parsing_result->descriptor.mode = VariableMode::kLet;
break;
default:
UNREACHABLE(); // by current callers
break;
}
VariableDeclarationParsingScope declaration(
impl(), parsing_result->descriptor.mode, names);
Scope* target_scope = IsLexicalVariableMode(parsing_result->descriptor.mode)
? scope()
: scope()->GetDeclarationScope();
auto declaration_it = target_scope->declarations()->end();
int bindings_start = peek_position();
do {
// Parse binding pattern.
FuncNameInferrerState fni_state(&fni_);
int decl_pos = peek_position();
IdentifierT name;
ExpressionT pattern;
// Check for an identifier first, so that we can elide the pattern in cases
// where there is no initializer (and so no proxy needs to be created).
if (V8_LIKELY(Token::IsAnyIdentifier(peek()))) {
name = ParseAndClassifyIdentifier(Next());
if (V8_UNLIKELY(is_strict(language_mode()) &&
impl()->IsEvalOrArguments(name))) {
impl()->ReportMessageAt(scanner()->location(),
MessageTemplate::kStrictEvalArguments);
return;
}
if (peek() == Token::ASSIGN ||
(var_context == kForStatement && PeekInOrOf()) ||
parsing_result->descriptor.mode == VariableMode::kLet) {
// Assignments need the variable expression for the assignment LHS, and
// for of/in will need it later, so create the expression now.
pattern = impl()->ExpressionFromIdentifier(name, decl_pos);
} else {
// Otherwise, elide the variable expression and just declare it.
impl()->DeclareIdentifier(name, decl_pos);
pattern = impl()->NullExpression();
}
} else {
name = impl()->NullIdentifier();
pattern = ParseBindingPattern();
DCHECK(!impl()->IsIdentifier(pattern));
}
Scanner::Location variable_loc = scanner()->location();
ExpressionT value = impl()->NullExpression();
int value_beg_pos = kNoSourcePosition;
if (Check(Token::ASSIGN)) {
DCHECK(!impl()->IsNull(pattern));
{
value_beg_pos = peek_position();
AcceptINScope scope(this, var_context != kForStatement);
value = ParseAssignmentExpression();
}
variable_loc.end_pos = end_position();
if (!parsing_result->first_initializer_loc.IsValid()) {
parsing_result->first_initializer_loc = variable_loc;
}
// Don't infer if it is "a = function(){...}();"-like expression.
if (impl()->IsIdentifier(pattern)) {
if (!value->IsCall() && !value->IsCallNew()) {
fni_.Infer();
} else {
fni_.RemoveLastFunction();
}
}
impl()->SetFunctionNameFromIdentifierRef(value, pattern);
} else {
#ifdef DEBUG
// We can fall through into here on error paths, so don't DCHECK those.
if (!has_error()) {
// We should never get identifier patterns for the non-initializer path,
// as those expressions should be elided.
DCHECK_EQ(!impl()->IsNull(name),
Token::IsAnyIdentifier(scanner()->current_token()));
DCHECK_IMPLIES(impl()->IsNull(pattern), !impl()->IsNull(name));
// The only times we have a non-null pattern are:
// 1. This is a destructuring declaration (with no initializer, which
// is immediately an error),
// 2. This is a declaration in a for in/of loop, or
// 3. This is a let (which has an implicit undefined initializer)
DCHECK_IMPLIES(
!impl()->IsNull(pattern),
!impl()->IsIdentifier(pattern) ||
(var_context == kForStatement && PeekInOrOf()) ||
parsing_result->descriptor.mode == VariableMode::kLet);
}
#endif
if (var_context != kForStatement || !PeekInOrOf()) {
// ES6 'const' and binding patterns require initializers.
if (parsing_result->descriptor.mode == VariableMode::kConst ||
impl()->IsNull(name)) {
impl()->ReportMessageAt(
Scanner::Location(decl_pos, end_position()),
MessageTemplate::kDeclarationMissingInitializer,
impl()->IsNull(name) ? "destructuring" : "const");
return;
}
// 'let x' initializes 'x' to undefined.
if (parsing_result->descriptor.mode == VariableMode::kLet) {
value = factory()->NewUndefinedLiteral(position());
}
}
}
int initializer_position = end_position();
auto declaration_end = target_scope->declarations()->end();
for (; declaration_it != declaration_end; ++declaration_it) {
declaration_it->var()->set_initializer_position(initializer_position);
}
// Patterns should be elided iff. they don't have an initializer.
DCHECK_IMPLIES(impl()->IsNull(pattern),
impl()->IsNull(value) ||
(var_context == kForStatement && PeekInOrOf()));
typename DeclarationParsingResult::Declaration decl(pattern, value);
decl.value_beg_pos = value_beg_pos;
parsing_result->declarations.push_back(decl);
} while (Check(Token::COMMA));
parsing_result->bindings_loc =
Scanner::Location(bindings_start, end_position());
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseFunctionDeclaration() {
Consume(Token::FUNCTION);
int pos = position();
ParseFunctionFlags flags = ParseFunctionFlag::kIsNormal;
if (Check(Token::MUL)) {
impl()->ReportMessageAt(
scanner()->location(),
MessageTemplate::kGeneratorInSingleStatementContext);
return impl()->NullStatement();
}
return ParseHoistableDeclaration(pos, flags, nullptr, false);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseHoistableDeclaration(
ZonePtrList<const AstRawString>* names, bool default_export) {
Consume(Token::FUNCTION);
int pos = position();
ParseFunctionFlags flags = ParseFunctionFlag::kIsNormal;
if (Check(Token::MUL)) {
flags |= ParseFunctionFlag::kIsGenerator;
}
return ParseHoistableDeclaration(pos, flags, names, default_export);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseHoistableDeclaration(
int pos, ParseFunctionFlags flags, ZonePtrList<const AstRawString>* names,
bool default_export) {
CheckStackOverflow();
// FunctionDeclaration ::
// 'function' Identifier '(' FormalParameters ')' '{' FunctionBody '}'
// 'function' '(' FormalParameters ')' '{' FunctionBody '}'
// GeneratorDeclaration ::
// 'function' '*' Identifier '(' FormalParameters ')' '{' FunctionBody '}'
// 'function' '*' '(' FormalParameters ')' '{' FunctionBody '}'
//
// The anonymous forms are allowed iff [default_export] is true.
//
// 'function' and '*' (if present) have been consumed by the caller.
DCHECK_IMPLIES((flags & ParseFunctionFlag::kIsAsync) != 0,
(flags & ParseFunctionFlag::kIsGenerator) == 0);
if ((flags & ParseFunctionFlag::kIsAsync) != 0 && Check(Token::MUL)) {
// Async generator
flags |= ParseFunctionFlag::kIsGenerator;
}
IdentifierT name;
FunctionNameValidity name_validity;
IdentifierT variable_name;
if (peek() == Token::LPAREN) {
if (default_export) {
impl()->GetDefaultStrings(&name, &variable_name);
name_validity = kSkipFunctionNameCheck;
} else {
ReportMessage(MessageTemplate::kMissingFunctionName);
return impl()->NullStatement();
}
} else {
bool is_strict_reserved = Token::IsStrictReservedWord(peek());
name = ParseIdentifier();
name_validity = is_strict_reserved ? kFunctionNameIsStrictReserved
: kFunctionNameValidityUnknown;
variable_name = name;
}
FuncNameInferrerState fni_state(&fni_);
impl()->PushEnclosingName(name);
FunctionKind function_kind = FunctionKindFor(flags);
FunctionLiteralT function = impl()->ParseFunctionLiteral(
name, scanner()->location(), name_validity, function_kind, pos,
FunctionSyntaxKind::kDeclaration, language_mode(), nullptr);
// In ES6, a function behaves as a lexical binding, except in
// a script scope, or the initial scope of eval or another function.
VariableMode mode =
(!scope()->is_declaration_scope() || scope()->is_module_scope())
? VariableMode::kLet
: VariableMode::kVar;
// Async functions don't undergo sloppy mode block scoped hoisting, and don't
// allow duplicates in a block. Both are represented by the
// sloppy_block_functions_. Don't add them to the map for async functions.
// Generators are also supposed to be prohibited; currently doing this behind
// a flag and UseCounting violations to assess web compatibility.
VariableKind kind = is_sloppy(language_mode()) &&
!scope()->is_declaration_scope() &&
flags == ParseFunctionFlag::kIsNormal
? SLOPPY_BLOCK_FUNCTION_VARIABLE
: NORMAL_VARIABLE;
return impl()->DeclareFunction(variable_name, function, mode, kind, pos,
end_position(), names);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseClassDeclaration(
ZonePtrList<const AstRawString>* names, bool default_export) {
// ClassDeclaration ::
// 'class' Identifier ('extends' LeftHandExpression)? '{' ClassBody '}'
// 'class' ('extends' LeftHandExpression)? '{' ClassBody '}'
//
// The anonymous form is allowed iff [default_export] is true.
//
// 'class' is expected to be consumed by the caller.
//
// A ClassDeclaration
//
// class C { ... }
//
// has the same semantics as:
//
// let C = class C { ... };
//
// so rewrite it as such.
int class_token_pos = position();
IdentifierT name = impl()->NullIdentifier();
bool is_strict_reserved = Token::IsStrictReservedWord(peek());
IdentifierT variable_name = impl()->NullIdentifier();
if (default_export && (peek() == Token::EXTENDS || peek() == Token::LBRACE)) {
impl()->GetDefaultStrings(&name, &variable_name);
} else {
name = ParseIdentifier();
variable_name = name;
}
ExpressionParsingScope no_expression_scope(impl());
ExpressionT value = ParseClassLiteral(name, scanner()->location(),
is_strict_reserved, class_token_pos);
no_expression_scope.ValidateExpression();
int end_pos = position();
return impl()->DeclareClass(variable_name, value, names, class_token_pos,
end_pos);
}
// Language extension which is only enabled for source files loaded
// through the API's extension mechanism. A native function
// declaration is resolved by looking up the function through a
// callback provided by the extension.
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseNativeDeclaration() {
function_state_->DisableOptimization(BailoutReason::kNativeFunctionLiteral);
int pos = peek_position();
Consume(Token::FUNCTION);
// Allow "eval" or "arguments" for backward compatibility.
IdentifierT name = ParseIdentifier();
Expect(Token::LPAREN);
if (peek() != Token::RPAREN) {
do {
ParseIdentifier();
} while (Check(Token::COMMA));
}
Expect(Token::RPAREN);
Expect(Token::SEMICOLON);
return impl()->DeclareNative(name, pos);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseAsyncFunctionDeclaration(
ZonePtrList<const AstRawString>* names, bool default_export) {
// AsyncFunctionDeclaration ::
// async [no LineTerminator here] function BindingIdentifier[Await]
// ( FormalParameters[Await] ) { AsyncFunctionBody }
DCHECK_EQ(scanner()->current_token(), Token::ASYNC);
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
impl()->ReportUnexpectedToken(Token::ESCAPED_KEYWORD);
}
int pos = position();
DCHECK(!scanner()->HasLineTerminatorBeforeNext());
Consume(Token::FUNCTION);
ParseFunctionFlags flags = ParseFunctionFlag::kIsAsync;
return ParseHoistableDeclaration(pos, flags, names, default_export);
}
template <typename Impl>
void ParserBase<Impl>::ParseFunctionBody(
StatementListT* body, IdentifierT function_name, int pos,
const FormalParametersT& parameters, FunctionKind kind,
FunctionSyntaxKind function_syntax_kind, FunctionBodyType body_type) {
if (IsResumableFunction(kind)) impl()->PrepareGeneratorVariables();
DeclarationScope* function_scope = parameters.scope;
DeclarationScope* inner_scope = function_scope;
// Building the parameter initialization block declares the parameters.
// TODO(verwaest): Rely on ArrowHeadParsingScope instead.
if (V8_UNLIKELY(!parameters.is_simple)) {
if (has_error()) return;
BlockT init_block = impl()->BuildParameterInitializationBlock(parameters);
if (IsAsyncFunction(kind) && !IsAsyncGeneratorFunction(kind)) {
init_block = impl()->BuildRejectPromiseOnException(init_block);
}
body->Add(init_block);
if (has_error()) return;
inner_scope = NewVarblockScope();
inner_scope->set_start_position(scanner()->location().beg_pos);
}
StatementListT inner_body(pointer_buffer());
{
BlockState block_state(&scope_, inner_scope);
if (body_type == FunctionBodyType::kExpression) {
ExpressionT expression = ParseAssignmentExpression();
if (IsAsyncFunction(kind)) {
BlockT block = factory()->NewBlock(1, true);
impl()->RewriteAsyncFunctionBody(&inner_body, block, expression);
} else {
inner_body.Add(
BuildReturnStatement(expression, expression->position()));
}
} else {
DCHECK(accept_IN_);
DCHECK_EQ(FunctionBodyType::kBlock, body_type);
// If we are parsing the source as if it is wrapped in a function, the
// source ends without a closing brace.
Token::Value closing_token =
function_syntax_kind == FunctionSyntaxKind::kWrapped ? Token::EOS
: Token::RBRACE;
if (IsAsyncGeneratorFunction(kind)) {
impl()->ParseAndRewriteAsyncGeneratorFunctionBody(pos, kind,
&inner_body);
} else if (IsGeneratorFunction(kind)) {
impl()->ParseAndRewriteGeneratorFunctionBody(pos, kind, &inner_body);
} else if (IsAsyncFunction(kind)) {
ParseAsyncFunctionBody(inner_scope, &inner_body);
} else {
ParseStatementList(&inner_body, closing_token);
}
if (IsDerivedConstructor(kind)) {
ExpressionParsingScope expression_scope(impl());
inner_body.Add(factory()->NewReturnStatement(impl()->ThisExpression(),
kNoSourcePosition));
expression_scope.ValidateExpression();
}
Expect(closing_token);
}
}
scope()->set_end_position(end_position());
bool allow_duplicate_parameters = false;
CheckConflictingVarDeclarations(inner_scope);
if (V8_LIKELY(parameters.is_simple)) {
DCHECK_EQ(inner_scope, function_scope);
if (is_sloppy(function_scope->language_mode())) {
impl()->InsertSloppyBlockFunctionVarBindings(function_scope);
}
allow_duplicate_parameters =
is_sloppy(function_scope->language_mode()) && !IsConciseMethod(kind);
} else {
DCHECK_NOT_NULL(inner_scope);
DCHECK_EQ(function_scope, scope());
DCHECK_EQ(function_scope, inner_scope->outer_scope());
impl()->SetLanguageMode(function_scope, inner_scope->language_mode());
if (is_sloppy(inner_scope->language_mode())) {
impl()->InsertSloppyBlockFunctionVarBindings(inner_scope);
}
inner_scope->set_end_position(end_position());
if (inner_scope->FinalizeBlockScope() != nullptr) {
BlockT inner_block = factory()->NewBlock(true, inner_body);
inner_body.Rewind();
inner_body.Add(inner_block);
inner_block->set_scope(inner_scope);
impl()->RecordBlockSourceRange(inner_block, scope()->end_position());
if (!impl()->HasCheckedSyntax()) {
const AstRawString* conflict = inner_scope->FindVariableDeclaredIn(
function_scope, VariableMode::kLastLexicalVariableMode);
if (conflict != nullptr) {
impl()->ReportVarRedeclarationIn(conflict, inner_scope);
}
}
impl()->InsertShadowingVarBindingInitializers(inner_block);
}
}
ValidateFormalParameters(language_mode(), parameters,
allow_duplicate_parameters);
if (!IsArrowFunction(kind)) {
// Declare arguments after parsing the function since lexical 'arguments'
// masks the arguments object. Declare arguments before declaring the
// function var since the arguments object masks 'function arguments'.
function_scope->DeclareArguments(ast_value_factory());
}
impl()->DeclareFunctionNameVar(function_name, function_syntax_kind,
function_scope);
inner_body.MergeInto(body);
}
template <typename Impl>
void ParserBase<Impl>::CheckArityRestrictions(int param_count,
FunctionKind function_kind,
bool has_rest,
int formals_start_pos,
int formals_end_pos) {
if (impl()->HasCheckedSyntax()) return;
if (IsGetterFunction(function_kind)) {
if (param_count != 0) {
impl()->ReportMessageAt(
Scanner::Location(formals_start_pos, formals_end_pos),
MessageTemplate::kBadGetterArity);
}
} else if (IsSetterFunction(function_kind)) {
if (param_count != 1) {
impl()->ReportMessageAt(
Scanner::Location(formals_start_pos, formals_end_pos),
MessageTemplate::kBadSetterArity);
}
if (has_rest) {
impl()->ReportMessageAt(
Scanner::Location(formals_start_pos, formals_end_pos),
MessageTemplate::kBadSetterRestParameter);
}
}
}
template <typename Impl>
bool ParserBase<Impl>::IsNextLetKeyword() {
DCHECK_EQ(Token::LET, peek());
Token::Value next_next = PeekAhead();
switch (next_next) {
case Token::LBRACE:
case Token::LBRACK:
case Token::IDENTIFIER:
case Token::STATIC:
case Token::LET: // `let let;` is disallowed by static semantics, but the
// token must be first interpreted as a keyword in order
// for those semantics to apply. This ensures that ASI is
// not honored when a LineTerminator separates the
// tokens.
case Token::YIELD:
case Token::AWAIT:
case Token::GET:
case Token::SET:
case Token::ASYNC:
return true;
case Token::FUTURE_STRICT_RESERVED_WORD:
return is_sloppy(language_mode());
default:
return false;
}
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseArrowFunctionLiteral(
const FormalParametersT& formal_parameters) {
const RuntimeCallCounterId counters[2] = {
RuntimeCallCounterId::kParseArrowFunctionLiteral,
RuntimeCallCounterId::kPreParseArrowFunctionLiteral};
RuntimeCallTimerScope runtime_timer(runtime_call_stats_,
counters[Impl::IsPreParser()],
RuntimeCallStats::kThreadSpecific);
base::ElapsedTimer timer;
if (V8_UNLIKELY(FLAG_log_function_events)) timer.Start();
DCHECK_IMPLIES(!has_error(), peek() == Token::ARROW);
if (!impl()->HasCheckedSyntax() && scanner_->HasLineTerminatorBeforeNext()) {
// ASI inserts `;` after arrow parameters if a line terminator is found.
// `=> ...` is never a valid expression, so report as syntax error.
// If next token is not `=>`, it's a syntax error anyways.
impl()->ReportUnexpectedTokenAt(scanner_->peek_location(), Token::ARROW);
return impl()->FailureExpression();
}
int expected_property_count = 0;
int suspend_count = 0;
int function_literal_id = GetNextFunctionLiteralId();
FunctionKind kind = formal_parameters.scope->function_kind();
FunctionLiteral::EagerCompileHint eager_compile_hint =
default_eager_compile_hint_;
bool can_preparse = impl()->parse_lazily() &&
eager_compile_hint == FunctionLiteral::kShouldLazyCompile;
// TODO(marja): consider lazy-parsing inner arrow functions too. is_this
// handling in Scope::ResolveVariable needs to change.
bool is_lazy_top_level_function =
can_preparse && impl()->AllowsLazyParsingWithoutUnresolvedVariables();
bool has_braces = true;
ProducedPreparseData* produced_preparse_data = nullptr;
StatementListT body(pointer_buffer());
{
FunctionState function_state(&function_state_, &scope_,
formal_parameters.scope);
Consume(Token::ARROW);
if (peek() == Token::LBRACE) {
// Multiple statement body
DCHECK_EQ(scope(), formal_parameters.scope);
if (is_lazy_top_level_function) {
// FIXME(marja): Arrow function parameters will be parsed even if the
// body is preparsed; move relevant parts of parameter handling to
// simulate consistent parameter handling.
// Building the parameter initialization block declares the parameters.
// TODO(verwaest): Rely on ArrowHeadParsingScope instead.
if (!formal_parameters.is_simple) {
impl()->BuildParameterInitializationBlock(formal_parameters);
if (has_error()) return impl()->FailureExpression();
}
// For arrow functions, we don't need to retrieve data about function
// parameters.
int dummy_num_parameters = -1;
int dummy_function_length = -1;
DCHECK_NE(kind & FunctionKind::kArrowFunction, 0);
bool did_preparse_successfully = impl()->SkipFunction(
nullptr, kind, FunctionSyntaxKind::kAnonymousExpression,
formal_parameters.scope, &dummy_num_parameters,
&dummy_function_length, &produced_preparse_data);
DCHECK_NULL(produced_preparse_data);
if (did_preparse_successfully) {
// Validate parameter names. We can do this only after preparsing the
// function, since the function can declare itself strict.
ValidateFormalParameters(language_mode(), formal_parameters, false);
} else {
// In case we did not sucessfully preparse the function because of an
// unidentified error we do a full reparse to return the error.
// Parse again in the outer scope, since the language mode may change.
BlockState block_state(&scope_, scope()->outer_scope());
ExpressionT expression = ParseConditionalExpression();
// Reparsing the head may have caused a stack overflow.
if (has_error()) return impl()->FailureExpression();
DeclarationScope* function_scope = next_arrow_function_info_.scope;
FunctionState function_state(&function_state_, &scope_,
function_scope);
Scanner::Location loc(function_scope->start_position(),
end_position());
FormalParametersT parameters(function_scope);
parameters.is_simple = function_scope->has_simple_parameters();
impl()->DeclareArrowFunctionFormalParameters(&parameters, expression,
loc);
next_arrow_function_info_.Reset();
Consume(Token::ARROW);
Consume(Token::LBRACE);
AcceptINScope scope(this, true);
FunctionParsingScope body_parsing_scope(impl());
ParseFunctionBody(&body, impl()->NullIdentifier(), kNoSourcePosition,
parameters, kind,
FunctionSyntaxKind::kAnonymousExpression,
FunctionBodyType::kBlock);
CHECK(has_error());
return impl()->FailureExpression();
}
} else {
Consume(Token::LBRACE);
AcceptINScope scope(this, true);
FunctionParsingScope body_parsing_scope(impl());
ParseFunctionBody(&body, impl()->NullIdentifier(), kNoSourcePosition,
formal_parameters, kind,
FunctionSyntaxKind::kAnonymousExpression,
FunctionBodyType::kBlock);
expected_property_count = function_state.expected_property_count();
}
} else {
// Single-expression body
has_braces = false;
FunctionParsingScope body_parsing_scope(impl());
ParseFunctionBody(&body, impl()->NullIdentifier(), kNoSourcePosition,
formal_parameters, kind,
FunctionSyntaxKind::kAnonymousExpression,
FunctionBodyType::kExpression);
expected_property_count = function_state.expected_property_count();
}
formal_parameters.scope->set_end_position(end_position());
// Validate strict mode.
if (is_strict(language_mode())) {
CheckStrictOctalLiteral(formal_parameters.scope->start_position(),
end_position());
}
suspend_count = function_state.suspend_count();
}
FunctionLiteralT function_literal = factory()->NewFunctionLiteral(
impl()->EmptyIdentifierString(), formal_parameters.scope, body,
expected_property_count, formal_parameters.num_parameters(),
formal_parameters.function_length,
FunctionLiteral::kNoDuplicateParameters,
FunctionSyntaxKind::kAnonymousExpression, eager_compile_hint,
formal_parameters.scope->start_position(), has_braces,
function_literal_id, produced_preparse_data);
function_literal->set_suspend_count(suspend_count);
function_literal->set_function_token_position(
formal_parameters.scope->start_position());
impl()->RecordFunctionLiteralSourceRange(function_literal);
impl()->AddFunctionForNameInference(function_literal);
if (V8_UNLIKELY((FLAG_log_function_events))) {
Scope* scope = formal_parameters.scope;
double ms = timer.Elapsed().InMillisecondsF();
const char* event_name =
is_lazy_top_level_function ? "preparse-no-resolution" : "parse";
const char* name = "arrow function";
logger_->FunctionEvent(event_name, flags().script_id(), ms,
scope->start_position(), scope->end_position(), name,
strlen(name));
}
return function_literal;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
IdentifierT name, Scanner::Location class_name_location,
bool name_is_strict_reserved, int class_token_pos) {
bool is_anonymous = impl()->IsNull(name);
// All parts of a ClassDeclaration and ClassExpression are strict code.
if (!impl()->HasCheckedSyntax() && !is_anonymous) {
if (name_is_strict_reserved) {
impl()->ReportMessageAt(class_name_location,
MessageTemplate::kUnexpectedStrictReserved);
return impl()->FailureExpression();
}
if (impl()->IsEvalOrArguments(name)) {
impl()->ReportMessageAt(class_name_location,
MessageTemplate::kStrictEvalArguments);
return impl()->FailureExpression();
}
}
ClassScope* class_scope = NewClassScope(scope(), is_anonymous);
BlockState block_state(&scope_, class_scope);
RaiseLanguageMode(LanguageMode::kStrict);
ClassInfo class_info(this);
class_info.is_anonymous = is_anonymous;
scope()->set_start_position(end_position());
if (Check(Token::EXTENDS)) {
ClassScope::HeritageParsingScope heritage(class_scope);
FuncNameInferrerState fni_state(&fni_);
ExpressionParsingScope scope(impl());
class_info.extends = ParseLeftHandSideExpression();
scope.ValidateExpression();
}
Expect(Token::LBRACE);
const bool has_extends = !impl()->IsNull(class_info.extends);
while (peek() != Token::RBRACE) {
if (Check(Token::SEMICOLON)) continue;
FuncNameInferrerState fni_state(&fni_);
// If we haven't seen the constructor yet, it potentially is the next
// property.
bool is_constructor = !class_info.has_seen_constructor;
ParsePropertyInfo prop_info(this);
prop_info.position = PropertyPosition::kClassLiteral;
ClassLiteralPropertyT property =
ParseClassPropertyDefinition(&class_info, &prop_info, has_extends);
if (has_error()) return impl()->FailureExpression();
ClassLiteralProperty::Kind property_kind =
ClassPropertyKindFor(prop_info.kind);
if (!class_info.has_static_computed_names && prop_info.is_static &&
prop_info.is_computed_name) {
class_info.has_static_computed_names = true;
}
is_constructor &= class_info.has_seen_constructor;
bool is_field = property_kind == ClassLiteralProperty::FIELD;
if (V8_UNLIKELY(prop_info.is_private)) {
DCHECK(!is_constructor);
class_info.requires_brand |= (!is_field && !prop_info.is_static);
bool is_method = property_kind == ClassLiteralProperty::METHOD;
class_info.has_private_methods |= is_method;
class_info.has_static_private_methods |= is_method && prop_info.is_static;
impl()->DeclarePrivateClassMember(class_scope, prop_info.name, property,
property_kind, prop_info.is_static,
&class_info);
impl()->InferFunctionName();
continue;
}
if (V8_UNLIKELY(is_field)) {
DCHECK(!prop_info.is_private);
if (prop_info.is_computed_name) {
class_info.computed_field_count++;
}
impl()->DeclarePublicClassField(class_scope, property,
prop_info.is_static,
prop_info.is_computed_name, &class_info);
impl()->InferFunctionName();
continue;
}
impl()->DeclarePublicClassMethod(name, property, is_constructor,
&class_info);
impl()->InferFunctionName();
}
Expect(Token::RBRACE);
int end_pos = end_position();
class_scope->set_end_position(end_pos);
VariableProxy* unresolvable = class_scope->ResolvePrivateNamesPartially();
if (unresolvable != nullptr) {
impl()->ReportMessageAt(Scanner::Location(unresolvable->position(),
unresolvable->position() + 1),
MessageTemplate::kInvalidPrivateFieldResolution,
unresolvable->raw_name());
return impl()->FailureExpression();
}
if (class_info.requires_brand) {
class_scope->DeclareBrandVariable(
ast_value_factory(), IsStaticFlag::kNotStatic, kNoSourcePosition);
}
bool should_save_class_variable_index =
class_scope->should_save_class_variable_index();
if (!is_anonymous || should_save_class_variable_index) {
impl()->DeclareClassVariable(class_scope, name, &class_info,
class_token_pos);
if (should_save_class_variable_index) {
class_scope->class_variable()->set_is_used();
class_scope->class_variable()->ForceContextAllocation();
}
}
return impl()->RewriteClassLiteral(class_scope, name, &class_info,
class_token_pos, end_pos);
}
template <typename Impl>
void ParserBase<Impl>::ParseAsyncFunctionBody(Scope* scope,
StatementListT* body) {
BlockT block = impl()->NullBlock();
{
StatementListT statements(pointer_buffer());
ParseStatementList(&statements, Token::RBRACE);
block = factory()->NewBlock(true, statements);
}
impl()->RewriteAsyncFunctionBody(
body, block, factory()->NewUndefinedLiteral(kNoSourcePosition));
scope->set_end_position(end_position());
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParseAsyncFunctionLiteral() {
// AsyncFunctionLiteral ::
// async [no LineTerminator here] function ( FormalParameters[Await] )
// { AsyncFunctionBody }
//
// async [no LineTerminator here] function BindingIdentifier[Await]
// ( FormalParameters[Await] ) { AsyncFunctionBody }
DCHECK_EQ(scanner()->current_token(), Token::ASYNC);
if (V8_UNLIKELY(scanner()->literal_contains_escapes())) {
impl()->ReportUnexpectedToken(Token::ESCAPED_KEYWORD);
}
int pos = position();
Consume(Token::FUNCTION);
IdentifierT name = impl()->NullIdentifier();
FunctionSyntaxKind syntax_kind = FunctionSyntaxKind::kAnonymousExpression;
ParseFunctionFlags flags = ParseFunctionFlag::kIsAsync;
if (Check(Token::MUL)) flags |= ParseFunctionFlag::kIsGenerator;
const FunctionKind kind = FunctionKindFor(flags);
bool is_strict_reserved = Token::IsStrictReservedWord(peek());
if (impl()->ParsingDynamicFunctionDeclaration()) {
// We don't want dynamic functions to actually declare their name
// "anonymous". We just want that name in the toString().
// Consuming token we did not peek yet, which could lead to a ILLEGAL token
// in the case of a stackoverflow.
Consume(Token::IDENTIFIER);
DCHECK_IMPLIES(!has_error(),
scanner()->CurrentSymbol(ast_value_factory()) ==
ast_value_factory()->anonymous_string());
} else if (peek_any_identifier()) {
syntax_kind = FunctionSyntaxKind::kNamedExpression;
name = ParseIdentifier(kind);
}
FunctionLiteralT result = impl()->ParseFunctionLiteral(
name, scanner()->location(),
is_strict_reserved ? kFunctionNameIsStrictReserved
: kFunctionNameValidityUnknown,
kind, pos, syntax_kind, language_mode(), nullptr);
if (impl()->IsNull(result)) return impl()->FailureExpression();
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseTemplateLiteral(
ExpressionT tag, int start, bool tagged) {
// A TemplateLiteral is made up of 0 or more TEMPLATE_SPAN tokens (literal
// text followed by a substitution expression), finalized by a single
// TEMPLATE_TAIL.
//
// In terms of draft language, TEMPLATE_SPAN may be either the TemplateHead or
// TemplateMiddle productions, while TEMPLATE_TAIL is either TemplateTail, or
// NoSubstitutionTemplate.
//
// When parsing a TemplateLiteral, we must have scanned either an initial
// TEMPLATE_SPAN, or a TEMPLATE_TAIL.
DCHECK(peek() == Token::TEMPLATE_SPAN || peek() == Token::TEMPLATE_TAIL);
if (tagged) {
// TaggedTemplate expressions prevent the eval compilation cache from being
// used. This flag is only used if an eval is being parsed.
set_allow_eval_cache(false);
}
bool forbid_illegal_escapes = !tagged;
// If we reach a TEMPLATE_TAIL first, we are parsing a NoSubstitutionTemplate.
// In this case we may simply consume the token and build a template with a
// single TEMPLATE_SPAN and no expressions.
if (peek() == Token::TEMPLATE_TAIL) {
Consume(Token::TEMPLATE_TAIL);
int pos = position();
typename Impl::TemplateLiteralState ts = impl()->OpenTemplateLiteral(pos);
bool is_valid = CheckTemplateEscapes(forbid_illegal_escapes);
impl()->AddTemplateSpan(&ts, is_valid, true);
return impl()->CloseTemplateLiteral(&ts, start, tag);
}
Consume(Token::TEMPLATE_SPAN);
int pos = position();
typename Impl::TemplateLiteralState ts = impl()->OpenTemplateLiteral(pos);
bool is_valid = CheckTemplateEscapes(forbid_illegal_escapes);
impl()->AddTemplateSpan(&ts, is_valid, false);
Token::Value next;
// If we open with a TEMPLATE_SPAN, we must scan the subsequent expression,
// and repeat if the following token is a TEMPLATE_SPAN as well (in this
// case, representing a TemplateMiddle).
do {
next = peek();
int expr_pos = peek_position();
AcceptINScope scope(this, true);
ExpressionT expression = ParseExpressionCoverGrammar();
impl()->AddTemplateExpression(&ts, expression);
if (peek() != Token::RBRACE) {
impl()->ReportMessageAt(Scanner::Location(expr_pos, peek_position()),
MessageTemplate::kUnterminatedTemplateExpr);
return impl()->FailureExpression();
}
// If we didn't die parsing that expression, our next token should be a
// TEMPLATE_SPAN or TEMPLATE_TAIL.
next = scanner()->ScanTemplateContinuation();
Next();
pos = position();
bool is_valid = CheckTemplateEscapes(forbid_illegal_escapes);
impl()->AddTemplateSpan(&ts, is_valid, next == Token::TEMPLATE_TAIL);
} while (next == Token::TEMPLATE_SPAN);
DCHECK_IMPLIES(!has_error(), next == Token::TEMPLATE_TAIL);
// Once we've reached a TEMPLATE_TAIL, we can close the TemplateLiteral.
return impl()->CloseTemplateLiteral(&ts, start, tag);
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::RewriteInvalidReferenceExpression(ExpressionT expression,
int beg_pos, int end_pos,
MessageTemplate message,
bool early_error) {
DCHECK(!IsValidReferenceExpression(expression));
if (impl()->IsIdentifier(expression)) {
DCHECK(is_strict(language_mode()));
DCHECK(impl()->IsEvalOrArguments(impl()->AsIdentifier(expression)));
ReportMessageAt(Scanner::Location(beg_pos, end_pos),
MessageTemplate::kStrictEvalArguments);
return impl()->FailureExpression();
}
if (expression->IsCall() && !expression->AsCall()->is_tagged_template() &&
!early_error) {
expression_scope()->RecordPatternError(
Scanner::Location(beg_pos, end_pos),
MessageTemplate::kInvalidDestructuringTarget);
// If it is a call, make it a runtime error for legacy web compatibility.
// Bug: https://bugs.chromium.org/p/v8/issues/detail?id=4480
// Rewrite `expr' to `expr[throw ReferenceError]'.
impl()->CountUsage(
is_strict(language_mode())
? v8::Isolate::kAssigmentExpressionLHSIsCallInStrict
: v8::Isolate::kAssigmentExpressionLHSIsCallInSloppy);
ExpressionT error = impl()->NewThrowReferenceError(message, beg_pos);
return factory()->NewProperty(expression, error, beg_pos);
}
// Tagged templates and other modern language features (which pass early_error
// = true) are exempt from the web compatibility hack. Throw a regular early
// error.
ReportMessageAt(Scanner::Location(beg_pos, end_pos), message);
return impl()->FailureExpression();
}
template <typename Impl>
void ParserBase<Impl>::ClassifyParameter(IdentifierT parameter, int begin,
int end) {
if (impl()->IsEvalOrArguments(parameter)) {
expression_scope()->RecordStrictModeParameterError(
Scanner::Location(begin, end), MessageTemplate::kStrictEvalArguments);
}
}
template <typename Impl>
void ParserBase<Impl>::ClassifyArrowParameter(
AccumulationScope* accumulation_scope, int position,
ExpressionT parameter) {
accumulation_scope->Accumulate();
if (parameter->is_parenthesized() ||
!(impl()->IsIdentifier(parameter) || parameter->IsPattern() ||
parameter->IsAssignment())) {
expression_scope()->RecordDeclarationError(
Scanner::Location(position, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
} else if (impl()->IsIdentifier(parameter)) {
ClassifyParameter(impl()->AsIdentifier(parameter), position,
end_position());
} else {
expression_scope()->RecordNonSimpleParameter();
}
}
template <typename Impl>
bool ParserBase<Impl>::IsValidReferenceExpression(ExpressionT expression) {
return IsAssignableIdentifier(expression) || expression->IsProperty();
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT
ParserBase<Impl>::ParsePossibleDestructuringSubPattern(
AccumulationScope* scope) {
if (scope) scope->Accumulate();
int begin = peek_position();
ExpressionT result = ParseAssignmentExpressionCoverGrammar();
if (IsValidReferenceExpression(result)) {
// Parenthesized identifiers and property references are allowed as part of
// a larger assignment pattern, even though parenthesized patterns
// themselves are not allowed, e.g., "[(x)] = []". Only accumulate
// assignment pattern errors if the parsed expression is more complex.
if (impl()->IsIdentifier(result)) {
if (result->is_parenthesized()) {
expression_scope()->RecordDeclarationError(
Scanner::Location(begin, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
}
IdentifierT identifier = impl()->AsIdentifier(result);
ClassifyParameter(identifier, begin, end_position());
} else {
DCHECK(result->IsProperty());
expression_scope()->RecordDeclarationError(
Scanner::Location(begin, end_position()),
MessageTemplate::kInvalidPropertyBindingPattern);
if (scope != nullptr) scope->ValidateExpression();
}
} else if (result->is_parenthesized() ||
(!result->IsPattern() && !result->IsAssignment())) {
expression_scope()->RecordPatternError(
Scanner::Location(begin, end_position()),
MessageTemplate::kInvalidDestructuringTarget);
}
return result;
}
template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseV8Intrinsic() {
// CallRuntime ::
// '%' Identifier Arguments
int pos = peek_position();
Consume(Token::MOD);
// Allow "eval" or "arguments" for backward compatibility.
IdentifierT name = ParseIdentifier();
if (peek() != Token::LPAREN) {
impl()->ReportUnexpectedToken(peek());
return impl()->FailureExpression();
}
bool has_spread;
ExpressionListT args(pointer_buffer());
ParseArguments(&args, &has_spread);
if (has_spread) {
ReportMessageAt(Scanner::Location(pos, position()),
MessageTemplate::kIntrinsicWithSpread);
return impl()->FailureExpression();
}
return impl()->NewV8Intrinsic(name, args, pos);
}
template <typename Impl>
void ParserBase<Impl>::ParseStatementList(StatementListT* body,
Token::Value end_token) {
// StatementList ::
// (StatementListItem)* <end_token>
DCHECK_NOT_NULL(body);
while (peek() == Token::STRING) {
bool use_strict = false;
bool use_asm = false;
Scanner::Location token_loc = scanner()->peek_location();
if (scanner()->NextLiteralExactlyEquals("use strict")) {
use_strict = true;
} else if (scanner()->NextLiteralExactlyEquals("use asm")) {
use_asm = true;
}
StatementT stat = ParseStatementListItem();
if (impl()->IsNull(stat)) return;
body->Add(stat);
if (!impl()->IsStringLiteral(stat)) break;
if (use_strict) {
// Directive "use strict" (ES5 14.1).
RaiseLanguageMode(LanguageMode::kStrict);
if (!scope()->HasSimpleParameters()) {
// TC39 deemed "use strict" directives to be an error when occurring
// in the body of a function with non-simple parameter list, on
// 29/7/2015. https://goo.gl/ueA7Ln
impl()->ReportMessageAt(token_loc,
MessageTemplate::kIllegalLanguageModeDirective,
"use strict");
return;
}
} else if (use_asm) {
// Directive "use asm".
impl()->SetAsmModule();
} else {
// Possibly an unknown directive.
// Should not change mode, but will increment usage counters
// as appropriate. Ditto usages below.
RaiseLanguageMode(LanguageMode::kSloppy);
}
}
while (peek() != end_token) {
StatementT stat = ParseStatementListItem();
if (impl()->IsNull(stat)) return;
if (stat->IsEmptyStatement()) continue;
body->Add(stat);
}
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseStatementListItem() {
// ECMA 262 6th Edition
// StatementListItem[Yield, Return] :
// Statement[?Yield, ?Return]
// Declaration[?Yield]
//
// Declaration[Yield] :
// HoistableDeclaration[?Yield]
// ClassDeclaration[?Yield]
// LexicalDeclaration[In, ?Yield]
//
// HoistableDeclaration[Yield, Default] :
// FunctionDeclaration[?Yield, ?Default]
// GeneratorDeclaration[?Yield, ?Default]
//
// LexicalDeclaration[In, Yield] :
// LetOrConst BindingList[?In, ?Yield] ;
switch (peek()) {
case Token::FUNCTION:
return ParseHoistableDeclaration(nullptr, false);
case Token::CLASS:
Consume(Token::CLASS);
return ParseClassDeclaration(nullptr, false);
case Token::VAR:
case Token::CONST:
return ParseVariableStatement(kStatementListItem, nullptr);
case Token::LET:
if (IsNextLetKeyword()) {
return ParseVariableStatement(kStatementListItem, nullptr);
}
break;
case Token::ASYNC:
if (PeekAhead() == Token::FUNCTION &&
!scanner()->HasLineTerminatorAfterNext()) {
Consume(Token::ASYNC);
return ParseAsyncFunctionDeclaration(nullptr, false);
}
break;
default:
break;
}
return ParseStatement(nullptr, nullptr, kAllowLabelledFunctionStatement);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels,
AllowLabelledFunctionStatement allow_function) {
// Statement ::
// Block
// VariableStatement
// EmptyStatement
// ExpressionStatement
// IfStatement
// IterationStatement
// ContinueStatement
// BreakStatement
// ReturnStatement
// WithStatement
// LabelledStatement
// SwitchStatement
// ThrowStatement
// TryStatement
// DebuggerStatement
// {own_labels} is always a subset of {labels}.
DCHECK_IMPLIES(labels == nullptr, own_labels == nullptr);
// Note: Since labels can only be used by 'break' and 'continue'
// statements, which themselves are only valid within blocks,
// iterations or 'switch' statements (i.e., BreakableStatements),
// labels can be simply ignored in all other cases; except for
// trivial labeled break statements 'label: break label' which is
// parsed into an empty statement.
switch (peek()) {
case Token::LBRACE:
return ParseBlock(labels);
case Token::SEMICOLON:
Next();
return factory()->EmptyStatement();
case Token::IF:
return ParseIfStatement(labels);
case Token::DO:
return ParseDoWhileStatement(labels, own_labels);
case Token::WHILE:
return ParseWhileStatement(labels, own_labels);
case Token::FOR:
if (V8_UNLIKELY(is_await_allowed() && PeekAhead() == Token::AWAIT)) {
return ParseForAwaitStatement(labels, own_labels);
}
return ParseForStatement(labels, own_labels);
case Token::CONTINUE:
return ParseContinueStatement();
case Token::BREAK:
return ParseBreakStatement(labels);
case Token::RETURN:
return ParseReturnStatement();
case Token::THROW:
return ParseThrowStatement();
case Token::TRY: {
// It is somewhat complicated to have labels on try-statements.
// When breaking out of a try-finally statement, one must take
// great care not to treat it as a fall-through. It is much easier
// just to wrap the entire try-statement in a statement block and
// put the labels there.
if (labels == nullptr) return ParseTryStatement();
StatementListT statements(pointer_buffer());
BlockT result = factory()->NewBlock(false, true);
Target target(this, result, labels, nullptr,
Target::TARGET_FOR_NAMED_ONLY);
StatementT statement = ParseTryStatement();
statements.Add(statement);
result->InitializeStatements(statements, zone());
return result;
}
case Token::WITH:
return ParseWithStatement(labels);
case Token::SWITCH:
return ParseSwitchStatement(labels);
case Token::FUNCTION:
// FunctionDeclaration only allowed as a StatementListItem, not in
// an arbitrary Statement position. Exceptions such as
// ES#sec-functiondeclarations-in-ifstatement-statement-clauses
// are handled by calling ParseScopedStatement rather than
// ParseStatement directly.
impl()->ReportMessageAt(scanner()->peek_location(),
is_strict(language_mode())
? MessageTemplate::kStrictFunction
: MessageTemplate::kSloppyFunction);
return impl()->NullStatement();
case Token::DEBUGGER:
return ParseDebuggerStatement();
case Token::VAR:
return ParseVariableStatement(kStatement, nullptr);
case Token::ASYNC:
if (!impl()->HasCheckedSyntax() &&
!scanner()->HasLineTerminatorAfterNext() &&
PeekAhead() == Token::FUNCTION) {
impl()->ReportMessageAt(
scanner()->peek_location(),
MessageTemplate::kAsyncFunctionInSingleStatementContext);
return impl()->NullStatement();
}
V8_FALLTHROUGH;
default:
return ParseExpressionOrLabelledStatement(labels, own_labels,
allow_function);
}
}
template <typename Impl>
typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseBlock(
ZonePtrList<const AstRawString>* labels) {
// Block ::
// '{' StatementList '}'
// Parse the statements and collect escaping labels.
BlockT body = factory()->NewBlock(false, labels != nullptr);
StatementListT statements(pointer_buffer());
CheckStackOverflow();
{
BlockState block_state(zone(), &scope_);
scope()->set_start_position(peek_position());
Target target(this, body, labels, nullptr, Target::TARGET_FOR_NAMED_ONLY);
Expect(Token::LBRACE);
while (peek() != Token::RBRACE) {
StatementT stat = ParseStatementListItem();
if (impl()->IsNull(stat)) return body;
if (stat->IsEmptyStatement()) continue;
statements.Add(stat);
}
Expect(Token::RBRACE);
int end_pos = end_position();
scope()->set_end_position(end_pos);
impl()->RecordBlockSourceRange(body, end_pos);
body->set_scope(scope()->FinalizeBlockScope());
}
body->InitializeStatements(statements, zone_);
return body;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseScopedStatement(
ZonePtrList<const AstRawString>* labels) {
if (is_strict(language_mode()) || peek() != Token::FUNCTION) {
return ParseStatement(labels, nullptr);
} else {
// Make a block around the statement for a lexical binding
// is introduced by a FunctionDeclaration.
BlockState block_state(zone(), &scope_);
scope()->set_start_position(scanner()->location().beg_pos);
BlockT block = factory()->NewBlock(1, false);
StatementT body = ParseFunctionDeclaration();
block->statements()->Add(body, zone());
scope()->set_end_position(end_position());
block->set_scope(scope()->FinalizeBlockScope());
return block;
}
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseVariableStatement(
VariableDeclarationContext var_context,
ZonePtrList<const AstRawString>* names) {
// VariableStatement ::
// VariableDeclarations ';'
// The scope of a var declared variable anywhere inside a function
// is the entire function (ECMA-262, 3rd, 10.1.3, and 12.2). Thus we can
// transform a source-level var declaration into a (Function) Scope
// declaration, and rewrite the source-level initialization into an assignment
// statement. We use a block to collect multiple assignments.
//
// We mark the block as initializer block because we don't want the
// rewriter to add a '.result' assignment to such a block (to get compliant
// behavior for code such as print(eval('var x = 7')), and for cosmetic
// reasons when pretty-printing. Also, unless an assignment (initialization)
// is inside an initializer block, it is ignored.
DeclarationParsingResult parsing_result;
ParseVariableDeclarations(var_context, &parsing_result, names);
ExpectSemicolon();
return impl()->BuildInitializationBlock(&parsing_result);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseDebuggerStatement() {
// In ECMA-262 'debugger' is defined as a reserved keyword. In some browser
// contexts this is used as a statement which invokes the debugger as i a
// break point is present.
// DebuggerStatement ::
// 'debugger' ';'
int pos = peek_position();
Consume(Token::DEBUGGER);
ExpectSemicolon();
return factory()->NewDebuggerStatement(pos);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseExpressionOrLabelledStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels,
AllowLabelledFunctionStatement allow_function) {
// ExpressionStatement | LabelledStatement ::
// Expression ';'
// Identifier ':' Statement
//
// ExpressionStatement[Yield] :
// [lookahead notin {{, function, class, let [}] Expression[In, ?Yield] ;
int pos = peek_position();
switch (peek()) {
case Token::FUNCTION:
case Token::LBRACE:
UNREACHABLE(); // Always handled by the callers.
case Token::CLASS:
ReportUnexpectedToken(Next());
return impl()->NullStatement();
case Token::LET: {
Token::Value next_next = PeekAhead();
// "let" followed by either "[", "{" or an identifier means a lexical
// declaration, which should not appear here.
// However, ASI may insert a line break before an identifier or a brace.
if (next_next != Token::LBRACK &&
((next_next != Token::LBRACE && next_next != Token::IDENTIFIER) ||
scanner_->HasLineTerminatorAfterNext())) {
break;
}
impl()->ReportMessageAt(scanner()->peek_location(),
MessageTemplate::kUnexpectedLexicalDeclaration);
return impl()->NullStatement();
}
default:
break;
}
bool starts_with_identifier = peek_any_identifier();
ExpressionT expr;
{
// Effectively inlines ParseExpression, so potential labels can be extracted
// from expression_scope.
ExpressionParsingScope expression_scope(impl());
AcceptINScope scope(this, true);
expr = ParseExpressionCoverGrammar();
expression_scope.ValidateExpression();
if (peek() == Token::COLON && starts_with_identifier &&
impl()->IsIdentifier(expr)) {
// The whole expression was a single identifier, and not, e.g.,
// something starting with an identifier or a parenthesized identifier.
DCHECK_EQ(expression_scope.variable_list()->length(), 1);
VariableProxy* label = expression_scope.variable_list()->at(0).first;
impl()->DeclareLabel(&labels, &own_labels, label->raw_name());
// 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.
this->scope()->DeleteUnresolved(label);
Consume(Token::COLON);
// ES#sec-labelled-function-declarations Labelled Function Declarations
if (peek() == Token::FUNCTION && is_sloppy(language_mode()) &&
allow_function == kAllowLabelledFunctionStatement) {
return ParseFunctionDeclaration();
}
return ParseStatement(labels, own_labels, allow_function);
}
}
// If we have an extension, we allow a native function declaration.
// A native function declaration starts with "native function" with
// no line-terminator between the two words.
if (extension_ != nullptr && peek() == Token::FUNCTION &&
!scanner()->HasLineTerminatorBeforeNext() && impl()->IsNative(expr) &&
!scanner()->literal_contains_escapes()) {
return ParseNativeDeclaration();
}
// Parsed expression statement, followed by semicolon.
ExpectSemicolon();
if (expr->IsFailureExpression()) return impl()->NullStatement();
return factory()->NewExpressionStatement(expr, pos);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseIfStatement(
ZonePtrList<const AstRawString>* labels) {
// IfStatement ::
// 'if' '(' Expression ')' Statement ('else' Statement)?
int pos = peek_position();
Consume(Token::IF);
Expect(Token::LPAREN);
ExpressionT condition = ParseExpression();
Expect(Token::RPAREN);
SourceRange then_range, else_range;
StatementT then_statement = impl()->NullStatement();
{
SourceRangeScope range_scope(scanner(), &then_range);
// Make a copy of {labels} to avoid conflicts with any
// labels that may be applied to the else clause below.
auto labels_copy =
labels == nullptr
? labels
: zone()->template New<ZonePtrList<const AstRawString>>(*labels,
zone());
then_statement = ParseScopedStatement(labels_copy);
}
StatementT else_statement = impl()->NullStatement();
if (Check(Token::ELSE)) {
else_statement = ParseScopedStatement(labels);
else_range = SourceRange::ContinuationOf(then_range, end_position());
} else {
else_statement = factory()->EmptyStatement();
}
StatementT stmt =
factory()->NewIfStatement(condition, then_statement, else_statement, pos);
impl()->RecordIfStatementSourceRange(stmt, then_range, else_range);
return stmt;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseContinueStatement() {
// ContinueStatement ::
// 'continue' Identifier? ';'
int pos = peek_position();
Consume(Token::CONTINUE);
IdentifierT label = impl()->NullIdentifier();
Token::Value tok = peek();
if (!scanner()->HasLineTerminatorBeforeNext() &&
!Token::IsAutoSemicolon(tok)) {
// ECMA allows "eval" or "arguments" as labels even in strict mode.
label = ParseIdentifier();
}
IterationStatementT target = LookupContinueTarget(label);
if (impl()->IsNull(target)) {
// Illegal continue statement.
MessageTemplate message = MessageTemplate::kIllegalContinue;
BreakableStatementT breakable_target = LookupBreakTarget(label);
if (impl()->IsNull(label)) {
message = MessageTemplate::kNoIterationStatement;
} else if (impl()->IsNull(breakable_target)) {
message = MessageTemplate::kUnknownLabel;
}
ReportMessage(message, label);
return impl()->NullStatement();
}
ExpectSemicolon();
StatementT stmt = factory()->NewContinueStatement(target, pos);
impl()->RecordJumpStatementSourceRange(stmt, end_position());
return stmt;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseBreakStatement(
ZonePtrList<const AstRawString>* labels) {
// BreakStatement ::
// 'break' Identifier? ';'
int pos = peek_position();
Consume(Token::BREAK);
IdentifierT label = impl()->NullIdentifier();
Token::Value tok = peek();
if (!scanner()->HasLineTerminatorBeforeNext() &&
!Token::IsAutoSemicolon(tok)) {
// ECMA allows "eval" or "arguments" as labels even in strict mode.
label = ParseIdentifier();
}
// Parse labeled break statements that target themselves into
// empty statements, e.g. 'l1: l2: l3: break l2;'
if (!impl()->IsNull(label) &&
impl()->ContainsLabel(labels, impl()->GetRawNameFromIdentifier(label))) {
ExpectSemicolon();
return factory()->EmptyStatement();
}
BreakableStatementT target = LookupBreakTarget(label);
if (impl()->IsNull(target)) {
// Illegal break statement.
MessageTemplate message = MessageTemplate::kIllegalBreak;
if (!impl()->IsNull(label)) {
message = MessageTemplate::kUnknownLabel;
}
ReportMessage(message, label);
return impl()->NullStatement();
}
ExpectSemicolon();
StatementT stmt = factory()->NewBreakStatement(target, pos);
impl()->RecordJumpStatementSourceRange(stmt, end_position());
return stmt;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseReturnStatement() {
// ReturnStatement ::
// 'return' [no line terminator] Expression? ';'
// Consume the return token. It is necessary to do that before
// reporting any errors on it, because of the way errors are
// reported (underlining).
Consume(Token::RETURN);
Scanner::Location loc = scanner()->location();
switch (GetDeclarationScope()->scope_type()) {
case SCRIPT_SCOPE:
case EVAL_SCOPE:
case MODULE_SCOPE:
impl()->ReportMessageAt(loc, MessageTemplate::kIllegalReturn);
return impl()->NullStatement();
default:
break;
}
Token::Value tok = peek();
ExpressionT return_value = impl()->NullExpression();
if (scanner()->HasLineTerminatorBeforeNext() || Token::IsAutoSemicolon(tok)) {
if (IsDerivedConstructor(function_state_->kind())) {
ExpressionParsingScope expression_scope(impl());
return_value = impl()->ThisExpression();
expression_scope.ValidateExpression();
}
} else {
return_value = ParseExpression();
}
ExpectSemicolon();
return_value = impl()->RewriteReturn(return_value, loc.beg_pos);
int continuation_pos = end_position();
StatementT stmt =
BuildReturnStatement(return_value, loc.beg_pos, continuation_pos);
impl()->RecordJumpStatementSourceRange(stmt, end_position());
return stmt;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseWithStatement(
ZonePtrList<const AstRawString>* labels) {
// WithStatement ::
// 'with' '(' Expression ')' Statement
Consume(Token::WITH);
int pos = position();
if (is_strict(language_mode())) {
ReportMessage(MessageTemplate::kStrictWith);
return impl()->NullStatement();
}
Expect(Token::LPAREN);
ExpressionT expr = ParseExpression();
Expect(Token::RPAREN);
Scope* with_scope = NewScope(WITH_SCOPE);
StatementT body = impl()->NullStatement();
{
BlockState block_state(&scope_, with_scope);
with_scope->set_start_position(scanner()->peek_location().beg_pos);
body = ParseStatement(labels, nullptr);
with_scope->set_end_position(end_position());
}
return factory()->NewWithStatement(with_scope, expr, body, pos);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseDoWhileStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
// DoStatement ::
// 'do' Statement 'while' '(' Expression ')' ';'
typename FunctionState::LoopScope loop_scope(function_state_);
auto loop = factory()->NewDoWhileStatement(peek_position());
Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
SourceRange body_range;
StatementT body = impl()->NullStatement();
Consume(Token::DO);
CheckStackOverflow();
{
SourceRangeScope range_scope(scanner(), &body_range);
body = ParseStatement(nullptr, nullptr);
}
Expect(Token::WHILE);
Expect(Token::LPAREN);
ExpressionT cond = ParseExpression();
Expect(Token::RPAREN);
// Allow do-statements to be terminated with and without
// semi-colons. This allows code such as 'do;while(0)return' to
// parse, which would not be the case if we had used the
// ExpectSemicolon() functionality here.
Check(Token::SEMICOLON);
loop->Initialize(cond, body);
impl()->RecordIterationStatementSourceRange(loop, body_range);
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseWhileStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
// WhileStatement ::
// 'while' '(' Expression ')' Statement
typename FunctionState::LoopScope loop_scope(function_state_);
auto loop = factory()->NewWhileStatement(peek_position());
Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
SourceRange body_range;
StatementT body = impl()->NullStatement();
Consume(Token::WHILE);
Expect(Token::LPAREN);
ExpressionT cond = ParseExpression();
Expect(Token::RPAREN);
{
SourceRangeScope range_scope(scanner(), &body_range);
body = ParseStatement(nullptr, nullptr);
}
loop->Initialize(cond, body);
impl()->RecordIterationStatementSourceRange(loop, body_range);
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseThrowStatement() {
// ThrowStatement ::
// 'throw' Expression ';'
Consume(Token::THROW);
int pos = position();
if (scanner()->HasLineTerminatorBeforeNext()) {
ReportMessage(MessageTemplate::kNewlineAfterThrow);
return impl()->NullStatement();
}
ExpressionT exception = ParseExpression();
ExpectSemicolon();
StatementT stmt = impl()->NewThrowStatement(exception, pos);
impl()->RecordThrowSourceRange(stmt, end_position());
return stmt;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseSwitchStatement(
ZonePtrList<const AstRawString>* labels) {
// SwitchStatement ::
// 'switch' '(' Expression ')' '{' CaseClause* '}'
// CaseClause ::
// 'case' Expression ':' StatementList
// 'default' ':' StatementList
int switch_pos = peek_position();
Consume(Token::SWITCH);
Expect(Token::LPAREN);
ExpressionT tag = ParseExpression();
Expect(Token::RPAREN);
auto switch_statement = factory()->NewSwitchStatement(tag, switch_pos);
{
BlockState cases_block_state(zone(), &scope_);
scope()->set_start_position(switch_pos);
scope()->SetNonlinear();
Target target(this, switch_statement, labels, nullptr,
Target::TARGET_FOR_ANONYMOUS);
bool default_seen = false;
Expect(Token::LBRACE);
while (peek() != Token::RBRACE) {
// An empty label indicates the default case.
ExpressionT label = impl()->NullExpression();
StatementListT statements(pointer_buffer());
SourceRange clause_range;
{
SourceRangeScope range_scope(scanner(), &clause_range);
if (Check(Token::CASE)) {
label = ParseExpression();
} else {
Expect(Token::DEFAULT);
if (default_seen) {
ReportMessage(MessageTemplate::kMultipleDefaultsInSwitch);
return impl()->NullStatement();
}
default_seen = true;
}
Expect(Token::COLON);
while (peek() != Token::CASE && peek() != Token::DEFAULT &&
peek() != Token::RBRACE) {
StatementT stat = ParseStatementListItem();
if (impl()->IsNull(stat)) return stat;
if (stat->IsEmptyStatement()) continue;
statements.Add(stat);
}
}
auto clause = factory()->NewCaseClause(label, statements);
impl()->RecordCaseClauseSourceRange(clause, clause_range);
switch_statement->cases()->Add(clause, zone());
}
Expect(Token::RBRACE);
int end_pos = end_position();
scope()->set_end_position(end_pos);
impl()->RecordSwitchStatementSourceRange(switch_statement, end_pos);
Scope* switch_scope = scope()->FinalizeBlockScope();
if (switch_scope != nullptr) {
return impl()->RewriteSwitchStatement(switch_statement, switch_scope);
}
return switch_statement;
}
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseTryStatement() {
// TryStatement ::
// 'try' Block Catch
// 'try' Block Finally
// 'try' Block Catch Finally
//
// Catch ::
// 'catch' '(' Identifier ')' Block
//
// Finally ::
// 'finally' Block
Consume(Token::TRY);
int pos = position();
BlockT try_block = ParseBlock(nullptr);
CatchInfo catch_info(this);
if (peek() != Token::CATCH && peek() != Token::FINALLY) {
ReportMessage(MessageTemplate::kNoCatchOrFinally);
return impl()->NullStatement();
}
SourceRange catch_range, finally_range;
BlockT catch_block = impl()->NullBlock();
{
SourceRangeScope catch_range_scope(scanner(), &catch_range);
if (Check(Token::CATCH)) {
bool has_binding;
has_binding = Check(Token::LPAREN);
if (has_binding) {
catch_info.scope = NewScope(CATCH_SCOPE);
catch_info.scope->set_start_position(scanner()->location().beg_pos);
{
BlockState catch_block_state(&scope_, catch_info.scope);
StatementListT catch_statements(pointer_buffer());
// Create a block scope to hold any lexical declarations created
// as part of destructuring the catch parameter.
{
BlockState catch_variable_block_state(zone(), &scope_);
scope()->set_start_position(position());
if (peek_any_identifier()) {
IdentifierT identifier = ParseNonRestrictedIdentifier();
RETURN_IF_PARSE_ERROR;
catch_info.variable = impl()->DeclareCatchVariableName(
catch_info.scope, identifier);
} else {
catch_info.variable = catch_info.scope->DeclareCatchVariableName(
ast_value_factory()->dot_catch_string());
auto declaration_it = scope()->declarations()->end();
VariableDeclarationParsingScope destructuring(
impl(), VariableMode::kLet, nullptr);
catch_info.pattern = ParseBindingPattern();
int initializer_position = end_position();
auto declaration_end = scope()->declarations()->end();
for (; declaration_it != declaration_end; ++declaration_it) {
declaration_it->var()->set_initializer_position(
initializer_position);
}
RETURN_IF_PARSE_ERROR;
catch_statements.Add(impl()->RewriteCatchPattern(&catch_info));
}
Expect(Token::RPAREN);
BlockT inner_block = ParseBlock(nullptr);
catch_statements.Add(inner_block);
// Check for `catch(e) { let e; }` and similar errors.
if (!impl()->HasCheckedSyntax()) {
Scope* inner_scope = inner_block->scope();
if (inner_scope != nullptr) {
const AstRawString* conflict = nullptr;
if (impl()->IsNull(catch_info.pattern)) {
const AstRawString* name = catch_info.variable->raw_name();
if (inner_scope->LookupLocal(name)) conflict = name;
} else {
conflict = inner_scope->FindVariableDeclaredIn(
scope(), VariableMode::kVar);
}
if (conflict != nullptr) {
impl()->ReportVarRedeclarationIn(conflict, inner_scope);
}
}
}
scope()->set_end_position(end_position());
catch_block = factory()->NewBlock(false, catch_statements);
catch_block->set_scope(scope()->FinalizeBlockScope());
}
}
catch_info.scope->set_end_position(end_position());
} else {
catch_block = ParseBlock(nullptr);
}
}
}
BlockT finally_block = impl()->NullBlock();
DCHECK(has_error() || peek() == Token::FINALLY ||
!impl()->IsNull(catch_block));
{
SourceRangeScope range_scope(scanner(), &finally_range);
if (Check(Token::FINALLY)) {
finally_block = ParseBlock(nullptr);
}
}
RETURN_IF_PARSE_ERROR;
return impl()->RewriteTryStatement(try_block, catch_block, catch_range,
finally_block, finally_range, catch_info,
pos);
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
// Either a standard for loop
// for (<init>; <cond>; <next>) { ... }
// or a for-each loop
// for (<each> of|in <iterable>) { ... }
//
// We parse a declaration/expression after the 'for (' and then read the first
// expression/declaration before we know if this is a for or a for-each.
typename FunctionState::LoopScope loop_scope(function_state_);
int stmt_pos = peek_position();
ForInfo for_info(this);
Consume(Token::FOR);
Expect(Token::LPAREN);
bool starts_with_let = peek() == Token::LET;
if (peek() == Token::CONST || (starts_with_let && IsNextLetKeyword())) {
// The initializer contains lexical declarations,
// so create an in-between scope.
BlockState for_state(zone(), &scope_);
scope()->set_start_position(position());
// Also record whether inner functions or evals are found inside
// this loop, as this information is used to simplify the desugaring
// if none are found.
typename FunctionState::FunctionOrEvalRecordingScope recording_scope(
function_state_);
// Create an inner block scope which will be the parent scope of scopes
// possibly created by ParseVariableDeclarations.
Scope* inner_block_scope = NewScope(BLOCK_SCOPE);
{
BlockState inner_state(&scope_, inner_block_scope);
ParseVariableDeclarations(kForStatement, &for_info.parsing_result,
&for_info.bound_names);
}
DCHECK(IsLexicalVariableMode(for_info.parsing_result.descriptor.mode));
for_info.position = position();
if (CheckInOrOf(&for_info.mode)) {
scope()->set_is_hidden();
return ParseForEachStatementWithDeclarations(
stmt_pos, &for_info, labels, own_labels, inner_block_scope);
}
Expect(Token::SEMICOLON);
// Parse the remaining code in the inner block scope since the declaration
// above was parsed there. We'll finalize the unnecessary outer block scope
// after parsing the rest of the loop.
StatementT result = impl()->NullStatement();
inner_block_scope->set_start_position(scope()->start_position());
{
BlockState inner_state(&scope_, inner_block_scope);
StatementT init =
impl()->BuildInitializationBlock(&for_info.parsing_result);
result = ParseStandardForLoopWithLexicalDeclarations(
stmt_pos, init, &for_info, labels, own_labels);
}
Scope* finalized = scope()->FinalizeBlockScope();
DCHECK_NULL(finalized);
USE(finalized);
return result;
}
StatementT init = impl()->NullStatement();
if (peek() == Token::VAR) {
ParseVariableDeclarations(kForStatement, &for_info.parsing_result,
&for_info.bound_names);
DCHECK_EQ(for_info.parsing_result.descriptor.mode, VariableMode::kVar);
for_info.position = scanner()->location().beg_pos;
if (CheckInOrOf(&for_info.mode)) {
return ParseForEachStatementWithDeclarations(stmt_pos, &for_info, labels,
own_labels, scope());
}
init = impl()->BuildInitializationBlock(&for_info.parsing_result);
} else if (peek() != Token::SEMICOLON) {
// The initializer does not contain declarations.
Scanner::Location next_loc = scanner()->peek_location();
int lhs_beg_pos = next_loc.beg_pos;
int lhs_end_pos;
bool is_for_each;
ExpressionT expression;
{
ExpressionParsingScope parsing_scope(impl());
AcceptINScope scope(this, false);
expression = ParseExpressionCoverGrammar();
// Initializer is reference followed by in/of.
lhs_end_pos = end_position();
is_for_each = CheckInOrOf(&for_info.mode);
if (is_for_each) {
if (starts_with_let && for_info.mode == ForEachStatement::ITERATE) {
impl()->ReportMessageAt(next_loc, MessageTemplate::kForOfLet);
return impl()->NullStatement();
}
if (expression->IsPattern()) {
parsing_scope.ValidatePattern(expression, lhs_beg_pos, lhs_end_pos);
} else {
expression = parsing_scope.ValidateAndRewriteReference(
expression, lhs_beg_pos, lhs_end_pos);
}
} else {
parsing_scope.ValidateExpression();
}
}
if (is_for_each) {
return ParseForEachStatementWithoutDeclarations(
stmt_pos, expression, lhs_beg_pos, lhs_end_pos, &for_info, labels,
own_labels);
}
// Initializer is just an expression.
init = factory()->NewExpressionStatement(expression, lhs_beg_pos);
}
Expect(Token::SEMICOLON);
// Standard 'for' loop, we have parsed the initializer at this point.
ExpressionT cond = impl()->NullExpression();
StatementT next = impl()->NullStatement();
StatementT body = impl()->NullStatement();
ForStatementT loop =
ParseStandardForLoop(stmt_pos, labels, own_labels, &cond, &next, &body);
RETURN_IF_PARSE_ERROR;
loop->Initialize(init, cond, next, body);
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseForEachStatementWithDeclarations(
int stmt_pos, ForInfo* for_info, ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels, Scope* inner_block_scope) {
// Just one declaration followed by in/of.
if (for_info->parsing_result.declarations.size() != 1) {
impl()->ReportMessageAt(for_info->parsing_result.bindings_loc,
MessageTemplate::kForInOfLoopMultiBindings,
ForEachStatement::VisitModeString(for_info->mode));
return impl()->NullStatement();
}
if (for_info->parsing_result.first_initializer_loc.IsValid() &&
(is_strict(language_mode()) ||
for_info->mode == ForEachStatement::ITERATE ||
IsLexicalVariableMode(for_info->parsing_result.descriptor.mode) ||
!impl()->IsIdentifier(
for_info->parsing_result.declarations[0].pattern))) {
impl()->ReportMessageAt(for_info->parsing_result.first_initializer_loc,
MessageTemplate::kForInOfLoopInitializer,
ForEachStatement::VisitModeString(for_info->mode));
return impl()->NullStatement();
}
BlockT init_block = impl()->RewriteForVarInLegacy(*for_info);
auto loop = factory()->NewForEachStatement(for_info->mode, stmt_pos);
Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
ExpressionT enumerable = impl()->NullExpression();
if (for_info->mode == ForEachStatement::ITERATE) {
AcceptINScope scope(this, true);
enumerable = ParseAssignmentExpression();
} else {
enumerable = ParseExpression();
}
Expect(Token::RPAREN);
if (IsLexicalVariableMode(for_info->parsing_result.descriptor.mode)) {
inner_block_scope->set_start_position(position());
}
ExpressionT each_variable = impl()->NullExpression();
BlockT body_block = impl()->NullBlock();
{
BlockState block_state(&scope_, inner_block_scope);
SourceRange body_range;
StatementT body = impl()->NullStatement();
{
SourceRangeScope range_scope(scanner(), &body_range);
body = ParseStatement(nullptr, nullptr);
}
impl()->RecordIterationStatementSourceRange(loop, body_range);
impl()->DesugarBindingInForEachStatement(for_info, &body_block,
&each_variable);
body_block->statements()->Add(body, zone());
if (IsLexicalVariableMode(for_info->parsing_result.descriptor.mode)) {
scope()->set_end_position(end_position());
body_block->set_scope(scope()->FinalizeBlockScope());
}
}
loop->Initialize(each_variable, enumerable, body_block);
init_block = impl()->CreateForEachStatementTDZ(init_block, *for_info);
// Parsed for-in loop w/ variable declarations.
if (!impl()->IsNull(init_block)) {
init_block->statements()->Add(loop, zone());
if (IsLexicalVariableMode(for_info->parsing_result.descriptor.mode)) {
scope()->set_end_position(end_position());
init_block->set_scope(scope()->FinalizeBlockScope());
}
return init_block;
}
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseForEachStatementWithoutDeclarations(
int stmt_pos, ExpressionT expression, int lhs_beg_pos, int lhs_end_pos,
ForInfo* for_info, ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
auto loop = factory()->NewForEachStatement(for_info->mode, stmt_pos);
Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
ExpressionT enumerable = impl()->NullExpression();
if (for_info->mode == ForEachStatement::ITERATE) {
AcceptINScope scope(this, true);
enumerable = ParseAssignmentExpression();
} else {
enumerable = ParseExpression();
}
Expect(Token::RPAREN);
StatementT body = impl()->NullStatement();
SourceRange body_range;
{
SourceRangeScope range_scope(scanner(), &body_range);
body = ParseStatement(nullptr, nullptr);
}
impl()->RecordIterationStatementSourceRange(loop, body_range);
RETURN_IF_PARSE_ERROR;
loop->Initialize(expression, enumerable, body);
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT
ParserBase<Impl>::ParseStandardForLoopWithLexicalDeclarations(
int stmt_pos, StatementT init, ForInfo* for_info,
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
// The condition and the next statement of the for loop must be parsed
// in a new scope.
Scope* inner_scope = NewScope(BLOCK_SCOPE);
ForStatementT loop = impl()->NullStatement();
ExpressionT cond = impl()->NullExpression();
StatementT next = impl()->NullStatement();
StatementT body = impl()->NullStatement();
{
BlockState block_state(&scope_, inner_scope);
scope()->set_start_position(scanner()->location().beg_pos);
loop =
ParseStandardForLoop(stmt_pos, labels, own_labels, &cond, &next, &body);
RETURN_IF_PARSE_ERROR;
scope()->set_end_position(end_position());
}
scope()->set_end_position(end_position());
if (for_info->bound_names.length() > 0 &&
function_state_->contains_function_or_eval()) {
scope()->set_is_hidden();
return impl()->DesugarLexicalBindingsInForStatement(
loop, init, cond, next, body, inner_scope, *for_info);
} else {
inner_scope = inner_scope->FinalizeBlockScope();
DCHECK_NULL(inner_scope);
USE(inner_scope);
}
Scope* for_scope = scope()->FinalizeBlockScope();
if (for_scope != nullptr) {
// Rewrite a for statement of the form
// for (const x = i; c; n) b
//
// into
//
// {
// const x = i;
// for (; c; n) b
// }
//
DCHECK(!impl()->IsNull(init));
BlockT block = factory()->NewBlock(2, false);
block->statements()->Add(init, zone());
block->statements()->Add(loop, zone());
block->set_scope(for_scope);
loop->Initialize(impl()->NullStatement(), cond, next, body);
return block;
}
loop->Initialize(init, cond, next, body);
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::ForStatementT ParserBase<Impl>::ParseStandardForLoop(
int stmt_pos, ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels, ExpressionT* cond,
StatementT* next, StatementT* body) {
CheckStackOverflow();
ForStatementT loop = factory()->NewForStatement(stmt_pos);
Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
if (peek() != Token::SEMICOLON) {
*cond = ParseExpression();
}
Expect(Token::SEMICOLON);
if (peek() != Token::RPAREN) {
ExpressionT exp = ParseExpression();
*next = factory()->NewExpressionStatement(exp, exp->position());
}
Expect(Token::RPAREN);
SourceRange body_range;
{
SourceRangeScope range_scope(scanner(), &body_range);
*body = ParseStatement(nullptr, nullptr);
}
impl()->RecordIterationStatementSourceRange(loop, body_range);
return loop;
}
template <typename Impl>
typename ParserBase<Impl>::StatementT ParserBase<Impl>::ParseForAwaitStatement(
ZonePtrList<const AstRawString>* labels,
ZonePtrList<const AstRawString>* own_labels) {
// for await '(' ForDeclaration of AssignmentExpression ')'
DCHECK(is_await_allowed());
typename FunctionState::LoopScope loop_scope(function_state_);
int stmt_pos = peek_position();
ForInfo for_info(this);
for_info.mode = ForEachStatement::ITERATE;
// Create an in-between scope for let-bound iteration variables.
BlockState for_state(zone(), &scope_);
Expect(Token::FOR);
Expect(Token::AWAIT);
Expect(Token::LPAREN);
scope()->set_start_position(scanner()->location().beg_pos);
scope()->set_is_hidden();
auto loop = factory()->NewForOfStatement(stmt_pos, IteratorType::kAsync);
// Two suspends: one for next() and one for return()
function_state_->AddSuspend();
function_state_->AddSuspend();
Target target(this, loop, labels, own_labels, Target::TARGET_FOR_ANONYMOUS);
ExpressionT each_variable = impl()->NullExpression();
bool has_declarations = false;
Scope* inner_block_scope = NewScope(BLOCK_SCOPE);
bool starts_with_let = peek() == Token::LET;
if (peek() == Token::VAR || peek() == Token::CONST ||
(starts_with_let && IsNextLetKeyword())) {
// The initializer contains declarations
// 'for' 'await' '(' ForDeclaration 'of' AssignmentExpression ')'
// Statement
// 'for' 'await' '(' 'var' ForBinding 'of' AssignmentExpression ')'
// Statement
has_declarations = true;
{
BlockState inner_state(&scope_, inner_block_scope);
ParseVariableDeclarations(kForStatement, &for_info.parsing_result,
&for_info.bound_names);
}
for_info.position = scanner()->location().beg_pos;
// Only a single declaration is allowed in for-await-of loops
if (for_info.parsing_result.declarations.size() != 1) {
impl()->ReportMessageAt(for_info.parsing_result.bindings_loc,
MessageTemplate::kForInOfLoopMultiBindings,
"for-await-of");
return impl()->NullStatement();
}
// for-await-of's declarations do not permit initializers.
if (for_info.parsing_result.first_initializer_loc.IsValid()) {
impl()->ReportMessageAt(for_info.parsing_result.first_initializer_loc,
MessageTemplate::kForInOfLoopInitializer,
"for-await-of");
return impl()->NullStatement();
}
} else {
// The initializer does not contain declarations.
// 'for' 'await' '(' LeftHandSideExpression 'of' AssignmentExpression ')'
// Statement
if (starts_with_let) {
impl()->ReportMessageAt(scanner()->peek_location(),
MessageTemplate::kForOfLet);
return impl()->NullStatement();
}
int lhs_beg_pos = peek_position();
BlockState inner_state(&scope_, inner_block_scope);
ExpressionParsingScope parsing_scope(impl());
ExpressionT lhs = each_variable = ParseLeftHandSideExpression();
int lhs_end_pos = end_position();
if (lhs->IsPattern()) {
parsing_scope.ValidatePattern(lhs, lhs_beg_pos, lhs_end_pos);
} else {
each_variable = parsing_scope.ValidateAndRewriteReference(
lhs, lhs_beg_pos, lhs_end_pos);
}
}
ExpectContextualKeyword(ast_value_factory()->of_string());
const bool kAllowIn = true;
ExpressionT iterable = impl()->NullExpression();
{
AcceptINScope scope(this, kAllowIn);
iterable = ParseAssignmentExpression();
}
Expect(Token::RPAREN);
StatementT body = impl()->NullStatement();
{
BlockState block_state(&scope_, inner_block_scope);
scope()->set_start_position(scanner()->location().beg_pos);
SourceRange body_range;
{
SourceRangeScope range_scope(scanner(), &body_range);
body = ParseStatement(nullptr, nullptr);
scope()->set_end_position(end_position());
}
impl()->RecordIterationStatementSourceRange(loop, body_range);
if (has_declarations) {
BlockT body_block = impl()->NullBlock();
impl()->DesugarBindingInForEachStatement(&for_info, &body_block,
&each_variable);
body_block->statements()->Add(body, zone());
body_block->set_scope(scope()->FinalizeBlockScope());
body = body_block;
} else {
Scope* block_scope = scope()->FinalizeBlockScope();
DCHECK_NULL(block_scope);
USE(block_scope);
}
}
loop->Initialize(each_variable, iterable, body);
if (!has_declarations) {
Scope* for_scope = scope()->FinalizeBlockScope();
DCHECK_NULL(for_scope);
USE(for_scope);
return loop;
}
BlockT init_block =
impl()->CreateForEachStatementTDZ(impl()->NullBlock(), for_info);
scope()->set_end_position(end_position());
Scope* for_scope = scope()->FinalizeBlockScope();
// Parsed for-in loop w/ variable declarations.
if (!impl()->IsNull(init_block)) {
init_block->statements()->Add(loop, zone());
init_block->set_scope(for_scope);
return init_block;
}
DCHECK_NULL(for_scope);
return loop;
}
template <typename Impl>
void ParserBase<Impl>::CheckClassMethodName(IdentifierT name,
ParsePropertyKind type,
ParseFunctionFlags flags,
bool is_static,
bool* has_seen_constructor) {
DCHECK(type == ParsePropertyKind::kMethod || IsAccessor(type));
AstValueFactory* avf = ast_value_factory();
if (impl()->IdentifierEquals(name, avf->private_constructor_string())) {
ReportMessage(MessageTemplate::kConstructorIsPrivate);
return;
} else if (is_static) {
if (impl()->IdentifierEquals(name, avf->prototype_string())) {
ReportMessage(MessageTemplate::kStaticPrototype);
return;
}
} else if (impl()->IdentifierEquals(name, avf->constructor_string())) {
if (flags != ParseFunctionFlag::kIsNormal || IsAccessor(type)) {
MessageTemplate msg = (flags & ParseFunctionFlag::kIsGenerator) != 0
? MessageTemplate::kConstructorIsGenerator
: (flags & ParseFunctionFlag::kIsAsync) != 0
? MessageTemplate::kConstructorIsAsync
: MessageTemplate::kConstructorIsAccessor;
ReportMessage(msg);
return;
}
if (*has_seen_constructor) {
ReportMessage(MessageTemplate::kDuplicateConstructor);
return;
}
*has_seen_constructor = true;
return;
}
}
template <typename Impl>
void ParserBase<Impl>::CheckClassFieldName(IdentifierT name, bool is_static) {
AstValueFactory* avf = ast_value_factory();
if (is_static && impl()->IdentifierEquals(name, avf->prototype_string())) {
ReportMessage(MessageTemplate::kStaticPrototype);
return;
}
if (impl()->IdentifierEquals(name, avf->constructor_string()) ||
impl()->IdentifierEquals(name, avf->private_constructor_string())) {
ReportMessage(MessageTemplate::kConstructorClassField);
return;
}
}
#undef RETURN_IF_PARSE_ERROR
} // namespace internal
} // namespace v8
#endif // V8_PARSING_PARSER_BASE_H_