src/parsing/parser-base.h

// 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/pointer-with-payload.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/log.h"
#include "src/logging/runtime-call-stats-scope.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/regexp/regexp.h"
#include "src/zone/zone-chunk-list.h"

namespace v8 {
namespace internal {

class PreParserIdentifier;

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 V8_NODISCARD 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 ClassStaticElementListT = typename Types::ClassStaticElementList;
  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,
             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),
        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()->single_parse_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 V8_NODISCARD 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:
      base::PointerWithPayload<FunctionState, bool, 1> state_and_prev_value_;
    };

    class V8_NODISCARD 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_elements(parser->impl()->NewClassStaticElementList(4)),
          instance_fields(parser->impl()->NewClassPropertyList(4)),
          constructor(parser->impl()->NullExpression()),
          has_seen_constructor(false),
          has_static_computed_names(false),
          has_static_elements(false),
          has_static_private_methods(false),
          has_static_blocks(false),
          has_instance_members(false),
          requires_brand(false),
          is_anonymous(false),
          has_private_methods(false),
          static_elements_scope(nullptr),
          instance_members_scope(nullptr),
          computed_field_count(0) {}
    ExpressionT extends;
    ClassPropertyListT public_members;
    ClassPropertyListT private_members;
    ClassStaticElementListT static_elements;
    ClassPropertyListT instance_fields;
    FunctionLiteralT constructor;

    bool has_seen_constructor;
    bool has_static_computed_names;
    bool has_static_elements;
    bool has_static_private_methods;
    bool has_static_blocks;
    bool has_instance_members;
    bool requires_brand;
    bool is_anonymous;
    bool has_private_methods;
    DeclarationScope* static_elements_scope;
    DeclarationScope* instance_members_scope;
    int computed_field_count;
    Variable* home_object_variable = nullptr;
    Variable* static_home_object_variable = nullptr;
  };

  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* NewBlockScopeForObjectLiteral() {
    Scope* scope = NewScope(BLOCK_SCOPE);
    scope->set_is_block_scope_for_object_literal();
    return scope;
  }

  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()) {
      if (flags().parsing_while_debugging() == ParsingWhileDebugging::kYes) {
        ReportMessageAt(scanner()->location(),
                        MessageTemplate::kAwaitNotInDebugEvaluate);
      } else {
        ReportMessageAt(scanner()->location(),
                        MessageTemplate::kAwaitNotInAsyncContext);
      }
      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() || IsModule(function_state_->kind());
  }
  bool is_await_as_identifier_disallowed() {
    return flags().is_module() ||
           IsAwaitAsIdentifierDisallowed(function_state_->kind());
  }
  const PendingCompilationErrorHandler* pending_error_handler() const {
    return pending_error_handler_;
  }
  PendingCompilationErrorHandler* pending_error_handler() {
    return pending_error_handler_;
  }

  // Report syntax errors.
  template <typename... Ts>
  V8_NOINLINE void ReportMessage(MessageTemplate message, const Ts&... args) {
    ReportMessageAt(scanner()->location(), message, args...);
  }

  template <typename... Ts>
  V8_NOINLINE void ReportMessageAt(Scanner::Location source_location,
                                   MessageTemplate message, const Ts&... args) {
    impl()->pending_error_handler()->ReportMessageAt(
        source_location.beg_pos, source_location.end_pos, message, args...);
    scanner()->set_parser_error();
  }

  V8_NOINLINE void ReportMessageAt(Scanner::Location source_location,
                                   MessageTemplate message,
                                   const PreParserIdentifier& arg0) {
    ReportMessageAt(source_location, message,
                    impl()->PreParserIdentifierToAstRawString(arg0));
  }

  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);

  // Similar logic to ParseAndClassifyIdentifier but the identifier is
  // already parsed in prop_info. Returns false if this is an invalid
  // identifier or an invalid use of the "arguments" keyword.
  V8_INLINE bool ClassifyPropertyIdentifier(Token::Value token,
                                            ParsePropertyInfo* prop_info);
  // 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();

  const AstRawString* GetNextSymbolForRegExpLiteral() const {
    return scanner()->NextSymbol(ast_value_factory());
  }
  bool ValidateRegExpLiteral(const AstRawString* pattern, RegExpFlags flags,
                             RegExpError* regexp_error);
  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);
  BlockT ParseClassStaticBlock(ClassInfo* class_info);
  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 ParseClassExpression(Scope* outer_scope);
  ExpressionT ParseClassLiteral(Scope* outer_scope, 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();
  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,
                    Scope* block_scope);
  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;
  }

  enum SubFunctionKind { kFunction, kNonStaticMethod, kStaticMethod };

  FunctionKind FunctionKindForImpl(SubFunctionKind sub_function_kind,
                                   ParseFunctionFlags flags) {
    static const FunctionKind kFunctionKinds[][2][2] = {
        {
            // SubFunctionKind::kNormalFunction
            {// is_generator=false
             FunctionKind::kNormalFunction, FunctionKind::kAsyncFunction},
            {// is_generator=true
             FunctionKind::kGeneratorFunction,
             FunctionKind::kAsyncGeneratorFunction},
        },
        {
            // SubFunctionKind::kNonStaticMethod
            {// is_generator=false
             FunctionKind::kConciseMethod, FunctionKind::kAsyncConciseMethod},
            {// is_generator=true
             FunctionKind::kConciseGeneratorMethod,
             FunctionKind::kAsyncConciseGeneratorMethod},
        },
        {
            // SubFunctionKind::kStaticMethod
            {// is_generator=false
             FunctionKind::kStaticConciseMethod,
             FunctionKind::kStaticAsyncConciseMethod},
            {// is_generator=true
             FunctionKind::kStaticConciseGeneratorMethod,
             FunctionKind::kStaticAsyncConciseGeneratorMethod},
        }};
    return kFunctionKinds[sub_function_kind]
                         [(flags & ParseFunctionFlag::kIsGenerator) != 0]
                         [(flags & ParseFunctionFlag::kIsAsync) != 0];
  }

  inline FunctionKind FunctionKindFor(ParseFunctionFlags flags) {
    return FunctionKindForImpl(SubFunctionKind::kFunction, flags);
  }

  inline FunctionKind MethodKindFor(bool is_static, ParseFunctionFlags flags) {
    return FunctionKindForImpl(is_static ? SubFunctionKind::kStaticMethod
                                         : SubFunctionKind::kNonStaticMethod,
                               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 = ReturnStatement::kFunctionLiteralReturnPosition) {
    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 V8_NODISCARD 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 V8_NODISCARD 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 V8_NODISCARD 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.
  // Stack of scopes for object literals we're currently parsing.
  Scope* object_literal_scope_ = nullptr;
  Scope* original_scope_;  // The top scope for the current parsing item.
  FunctionState* function_state_;  // Function state stack.
  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>
bool ParserBase<Impl>::ClassifyPropertyIdentifier(
    Token::Value next, ParsePropertyInfo* prop_info) {
  // Updates made here must be reflected on ParseAndClassifyIdentifier.
  if (V8_LIKELY(base::IsInRange(next, Token::IDENTIFIER, Token::ASYNC))) {
    if (V8_UNLIKELY(impl()->IsArguments(prop_info->name) &&
                    scope()->ShouldBanArguments())) {
      ReportMessage(
          MessageTemplate::kArgumentsDisallowedInInitializerAndStaticBlock);
      return false;
    }
    return true;
  }

  if (!Token::IsValidIdentifier(next, language_mode(), is_generator(),
                                is_await_as_identifier_disallowed())) {
    ReportUnexpectedToken(next);
    return false;
  }

  DCHECK(!prop_info->is_computed_name);

  if (next == Token::AWAIT) {
    DCHECK(!is_async_function());
    expression_scope()->RecordAsyncArrowParametersError(
        scanner()->peek_location(), MessageTemplate::kAwaitBindingIdentifier);
  }
  return true;
}

template <typename Impl>
typename ParserBase<Impl>::IdentifierT
ParserBase<Impl>::ParseAndClassifyIdentifier(Token::Value next) {
  // Updates made here must be reflected on ClassifyPropertyIdentifier.
  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::kArgumentsDisallowedInInitializerAndStaticBlock);
      return impl()->EmptyIdentifierString();
    }
    return name;
  }

  if (!Token::IsValidIdentifier(next, language_mode(), is_generator(),
                                is_await_as_identifier_disallowed())) {
    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() ||
              IsAwaitAsIdentifierDisallowed(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>
bool ParserBase<Impl>::ValidateRegExpLiteral(const AstRawString* pattern,
                                             RegExpFlags flags,
                                             RegExpError* regexp_error) {
  // TODO(jgruber): If already validated in the preparser, skip validation in
  // the parser.
  DisallowGarbageCollection no_gc;
  ZoneScope zone_scope(zone());  // Free regexp parser memory after use.
  const unsigned char* d = pattern->raw_data();
  if (pattern->is_one_byte()) {
    return RegExp::VerifySyntax(zone(), stack_limit(),
                                static_cast<const uint8_t*>(d),
                                pattern->length(), flags, regexp_error, no_gc);
  } else {
    return RegExp::VerifySyntax(zone(), stack_limit(),
                                reinterpret_cast<const uint16_t*>(d),
                                pattern->length(), flags, regexp_error, no_gc);
  }
}

template <typename Impl>
typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseRegExpLiteral() {
  int pos = peek_position();
  if (!scanner()->ScanRegExpPattern()) {
    Next();
    ReportMessage(MessageTemplate::kUnterminatedRegExp);
    return impl()->FailureExpression();
  }

  const AstRawString* js_pattern = GetNextSymbolForRegExpLiteral();
  base::Optional<RegExpFlags> flags = scanner()->ScanRegExpFlags();
  if (!flags.has_value()) {
    Next();
    ReportMessage(MessageTemplate::kMalformedRegExpFlags);
    return impl()->FailureExpression();
  }
  Next();
  RegExpError regexp_error;
  if (!ValidateRegExpLiteral(js_pattern, flags.value(), &regexp_error)) {
    if (RegExpErrorIsStackOverflow(regexp_error)) set_stack_overflow();
    ReportMessage(MessageTemplate::kMalformedRegExp, js_pattern,
                  RegExpErrorString(regexp_error));
    return impl()->FailureExpression();
  }
  return factory()->NewRegExpLiteral(js_pattern, flags.value(), 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: {
      return ParseSuperExpression();
    }
    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)) {
        // clear last next_arrow_function_info tracked strict parameters error.
        next_arrow_function_info_.ClearStrictParameterError();

        // ()=>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: {
      return ParseClassExpression(scope());
    }

    case Token::TEMPLATE_SPAN:
    case Token::TEMPLATE_TAIL:
      return ParseTemplateLiteral(impl()->NullExpression(), beg_pos, false);

    case Token::MOD:
      if (flags().allow_natives_syntax() || impl()->ParsingExtension()) {
        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();
      }
      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);
  }

  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->is_static, 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;
      if (prop_info->is_static) {
        kind = is_get ? FunctionKind::kStaticGetterFunction
                      : FunctionKind::kStaticSetterFunction;
      } else {
        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_elements_scope
                : class_info->instance_members_scope;
  FunctionKind function_kind =
      is_static ? FunctionKind::kClassStaticInitializerFunction
                : FunctionKind::kClassMembersInitializerFunction;

  if (initializer_scope == nullptr) {
    initializer_scope = NewFunctionScope(function_kind);
    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);
  }

  if (is_static) {
    // For the instance initializer, we will save the positions
    // later with the positions of the class body so that we can reparse
    // it later.
    // TODO(joyee): Make scopes be non contiguous.
    initializer_scope->set_start_position(beg_pos);
    initializer_scope->set_end_position(end_position());
    class_info->static_elements_scope = initializer_scope;
    class_info->has_static_elements = true;
  } else {
    class_info->instance_members_scope = initializer_scope;
    class_info->has_instance_members = true;
  }

  return initializer;
}

template <typename Impl>
typename ParserBase<Impl>::BlockT ParserBase<Impl>::ParseClassStaticBlock(
    ClassInfo* class_info) {
  Consume(Token::STATIC);

  DeclarationScope* initializer_scope = class_info->static_elements_scope;
  if (initializer_scope == nullptr) {
    initializer_scope =
        NewFunctionScope(FunctionKind::kClassStaticInitializerFunction);
    initializer_scope->set_start_position(position());
    initializer_scope->SetLanguageMode(LanguageMode::kStrict);
    class_info->static_elements_scope = initializer_scope;
  }

  FunctionState initializer_state(&function_state_, &scope_, initializer_scope);
  AcceptINScope accept_in(this, true);

  // Each static block has its own var and lexical scope, so make a new var
  // block scope instead of using the synthetic members initializer function
  // scope.
  BlockT static_block = ParseBlock(nullptr, NewVarblockScope());
  initializer_scope->set_end_position(end_position());
  class_info->has_static_elements = true;
  return static_block;
}

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;

  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 (!ClassifyPropertyIdentifier(name_token, prop_info)) {
        return impl()->NullLiteralProperty();
      }

      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);

      std::unique_ptr<BlockState> block_state;
      if (object_literal_scope_ != nullptr) {
        DCHECK_EQ(object_literal_scope_->outer_scope(), scope_);
        block_state.reset(new BlockState(&scope_, object_literal_scope_));
      }
      constexpr bool kIsStatic = false;
      FunctionKind kind = MethodKindFor(kIsStatic, 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 = prop_info->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());
      }

      std::unique_ptr<BlockState> block_state;
      if (object_literal_scope_ != nullptr) {
        DCHECK_EQ(object_literal_scope_->outer_scope(), scope_);
        block_state.reset(new BlockState(&scope_, object_literal_scope_));
      }

      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());

  // If methods appear inside the object literal, we'll enter this scope.
  Scope* block_scope = NewBlockScopeForObjectLiteral();
  block_scope->set_start_position(pos);
  BlockState object_literal_scope_state(&object_literal_scope_, block_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();
  }

  Variable* home_object = nullptr;
  if (block_scope->needs_home_object()) {
    home_object = block_scope->DeclareHomeObjectVariable(ast_value_factory());
    block_scope->set_end_position(end_position());
  } else {
    block_scope = block_scope->FinalizeBlockScope();
    DCHECK_NULL(block_scope);
  }

  // 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, home_object));
}

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);