js/src/frontend/Parser.h
author Tom Tung <shes050117@gmail.com>
Mon, 20 May 2019 14:13:27 +0000
changeset 474523 29bdbbe89264b91d1bd4205c45536c9222a8d6ee
parent 473558 c706eab3c639f68720b3f3d634b29424da7f6360
permissions -rw-r--r--
Bug 1546752 - Stop creating, writing, and reading the .metadata file in QuotaManager except the upgrades; r=janv The main goal of this issue is to reduce IO during the storage initialization and stop creating .metadata file since we already have .metadata-v2 file to track the information for the origin directory. Therefore, this patch only stop create, write, and read the .metadata file. And, leaving the work for removing it to the next minor upgrade. Differential Revision: https://phabricator.services.mozilla.com/D28824

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* JS parser. */

#ifndef frontend_Parser_h
#define frontend_Parser_h

/*
 * [SMDOC] JS Parser
 *
 * JS parsers capable of generating ASTs from source text.
 *
 * A parser embeds token stream information, then gets and matches tokens to
 * generate a syntax tree that, if desired, BytecodeEmitter will use to compile
 * bytecode.
 *
 * Like token streams (see the comment near the top of TokenStream.h), parser
 * classes are heavily templatized -- along the token stream's character-type
 * axis, and also along a full-parse/syntax-parse axis.  Certain limitations of
 * C++ (primarily the inability to partially specialize function templates),
 * plus the desire to minimize compiled code size in duplicate function
 * template instantiations wherever possible, mean that Parser exhibits much of
 * the same unholy template/inheritance complexity as token streams.
 *
 * == ParserSharedBase → JS::AutoGCRooter ==
 *
 * ParserSharedBase is the base class for both regular JS and BinAST parser.
 * This class contains common fields and methods between both parsers.
 *
 * Of particular note: making ParserSharedBase inherit JS::AutoGCRooter (rather
 * than placing it under one of the more-derived parser classes) means that all
 * parsers can be traced using the same AutoGCRooter mechanism: it's not
 * necessary to have separate tracing functionality for syntax/full parsers or
 * parsers of different character types.
 *
 * == ParserBase → ParserSharedBase, ErrorReportMixin ==
 *
 * ParserBase is the base class for regular JS parser, shared by all regular JS
 * parsers of all character types and parse-handling behavior.  It stores
 * everything character- and handler-agnostic.
 *
 * ParserBase's most important field is the parser's token stream's
 * |TokenStreamAnyChars| component, for all tokenizing aspects that are
 * character-type-agnostic.  The character-type-sensitive components residing
 * in |TokenStreamSpecific| (see the comment near the top of TokenStream.h)
 * live elsewhere in this hierarchy.  These separate locations are the reason
 * for the |AnyCharsAccess| template parameter to |TokenStreamChars| and
 * |TokenStreamSpecific|.
 *
 * == PerHandlerParser<ParseHandler> → ParserBase ==
 *
 * Certain parsing behavior varies between full parsing and syntax-only parsing
 * but does not vary across source-text character types.  For example, the work
 * to "create an arguments object for a function" obviously varies between
 * syntax and full parsing but (because no source characters are examined) does
 * not vary by source text character type.  Such functionality is implemented
 * through functions in PerHandlerParser.
 *
 * Functionality only used by syntax parsing or full parsing doesn't live here:
 * it should be implemented in the appropriate Parser<ParseHandler> (described
 * further below).
 *
 * == GeneralParser<ParseHandler, Unit> → PerHandlerParser<ParseHandler> ==
 *
 * Most parsing behavior varies across the character-type axis (and possibly
 * along the full/syntax axis).  For example:
 *
 *   * Parsing ECMAScript's Expression production, implemented by
 *     GeneralParser::expr, varies in this manner: different types are used to
 *     represent nodes in full and syntax parsing (ParseNode* versus an enum),
 *     and reading the tokens comprising the expression requires inspecting
 *     individual characters (necessarily dependent upon character type).
 *   * Reporting an error or warning does not depend on the full/syntax parsing
 *     distinction.  But error reports and warnings include a line of context
 *     (or a slice of one), for pointing out where a mistake was made.
 *     Computing such line of context requires inspecting the source text to
 *     make that line/slice of context, which requires knowing the source text
 *     character type.
 *
 * Such functionality, implemented using identical function code across these
 * axes, should live in GeneralParser.
 *
 * GeneralParser's most important field is the parser's token stream's
 * |TokenStreamSpecific| component, for all aspects of tokenizing that (contra
 * |TokenStreamAnyChars| in ParserBase above) are character-type-sensitive.  As
 * noted above, this field's existence separate from that in ParserBase
 * motivates the |AnyCharsAccess| template parameters on various token stream
 * classes.
 *
 * Everything in PerHandlerParser *could* be folded into GeneralParser (below)
 * if desired.  We don't fold in this manner because all such functions would
 * be instantiated once per Unit -- but if exactly equivalent code would be
 * generated (because PerHandlerParser functions have no awareness of Unit),
 * it's risky to *depend* upon the compiler coalescing the instantiations into
 * one in the final binary.  PerHandlerParser guarantees no duplication.
 *
 * == Parser<ParseHandler, Unit> final → GeneralParser<ParseHandler, Unit> ==
 *
 * The final (pun intended) axis of complexity lies in Parser.
 *
 * Some functionality depends on character type, yet also is defined in
 * significantly different form in full and syntax parsing.  For example,
 * attempting to parse the source text of a module will do so in full parsing
 * but immediately fail in syntax parsing -- so the former is a mess'o'code
 * while the latter is effectively |return null();|.  Such functionality is
 * defined in Parser<SyntaxParseHandler or FullParseHandler, Unit> as
 * appropriate.
 *
 * There's a crucial distinction between GeneralParser and Parser, that
 * explains why both must exist (despite taking exactly the same template
 * parameters, and despite GeneralParser and Parser existing in a one-to-one
 * relationship).  GeneralParser is one unspecialized template class:
 *
 *   template<class ParseHandler, typename Unit>
 *   class GeneralParser : ...
 *   {
 *     ...parsing functions...
 *   };
 *
 * but Parser is one undefined template class with two separate
 * specializations:
 *
 *   // Declare, but do not define.
 *   template<class ParseHandler, typename Unit> class Parser;
 *
 *   // Define a syntax-parsing specialization.
 *   template<typename Unit>
 *   class Parser<SyntaxParseHandler, Unit> final
 *     : public GeneralParser<SyntaxParseHandler, Unit>
 *   {
 *     ...parsing functions...
 *   };
 *
 *   // Define a full-parsing specialization.
 *   template<typename Unit>
 *   class Parser<SyntaxParseHandler, Unit> final
 *     : public GeneralParser<SyntaxParseHandler, Unit>
 *   {
 *     ...parsing functions...
 *   };
 *
 * This odd distinction is necessary because C++ unfortunately doesn't allow
 * partial function specialization:
 *
 *   // BAD: You can only specialize a template function if you specify *every*
 *   //      template parameter, i.e. ParseHandler *and* Unit.
 *   template<typename Unit>
 *   void
 *   GeneralParser<SyntaxParseHandler, Unit>::foo() {}
 *
 * But if you specialize Parser *as a class*, then this is allowed:
 *
 *   template<typename Unit>
 *   void
 *   Parser<SyntaxParseHandler, Unit>::foo() {}
 *
 *   template<typename Unit>
 *   void
 *   Parser<FullParseHandler, Unit>::foo() {}
 *
 * because the only template parameter on the function is Unit -- and so all
 * template parameters *are* varying, not a strict subset of them.
 *
 * So -- any parsing functionality that is differently defined for different
 * ParseHandlers, *but* is defined textually identically for different Unit
 * (even if different code ends up generated for them by the compiler), should
 * reside in Parser.
 */

#include "mozilla/Array.h"
#include "mozilla/Maybe.h"
#include "mozilla/TypeTraits.h"

#include "jspubtd.h"

#include "ds/Nestable.h"
#include "frontend/BytecodeCompiler.h"
#include "frontend/ErrorReporter.h"
#include "frontend/FullParseHandler.h"
#include "frontend/NameAnalysisTypes.h"
#include "frontend/NameCollections.h"
#include "frontend/ParseContext.h"
#include "frontend/SharedContext.h"
#include "frontend/SyntaxParseHandler.h"
#include "frontend/TokenStream.h"

#include "vm/ErrorReporting.h"

namespace js {

class ModuleObject;

namespace frontend {

template <class ParseHandler, typename Unit>
class GeneralParser;

class SourceParseContext : public ParseContext {
 public:
  template <typename ParseHandler, typename Unit>
  SourceParseContext(GeneralParser<ParseHandler, Unit>* prs, SharedContext* sc,
                     Directives* newDirectives)
      : ParseContext(prs->cx_, prs->pc_, sc, prs->tokenStream, prs->usedNames_,
                     newDirectives,
                     mozilla::IsSame<ParseHandler, FullParseHandler>::value) {}
};

enum VarContext { HoistVars, DontHoistVars };
enum PropListType { ObjectLiteral, ClassBody, DerivedClassBody };
enum class PropertyType {
  Normal,
  Shorthand,
  CoverInitializedName,
  Getter,
  Setter,
  Method,
  GeneratorMethod,
  AsyncMethod,
  AsyncGeneratorMethod,
  Constructor,
  DerivedConstructor,
  Field,
};

enum AwaitHandling : uint8_t {
  AwaitIsName,
  AwaitIsKeyword,
  AwaitIsModuleKeyword
};

template <class ParseHandler, typename Unit>
class AutoAwaitIsKeyword;

template <class ParseHandler, typename Unit>
class AutoInParametersOfAsyncFunction;

class MOZ_STACK_CLASS ParserSharedBase : private JS::AutoGCRooter {
 public:
  enum class Kind { Parser, BinASTParser };

  ParserSharedBase(JSContext* cx, LifoAlloc& alloc, UsedNameTracker& usedNames,
                   ScriptSourceObject* sourceObject, Kind kind);
  ~ParserSharedBase();

 public:
  JSContext* const cx_;

  LifoAlloc& alloc_;

  LifoAlloc::Mark tempPoolMark_;

  // list of parsed objects and BigInts for GC tracing
  TraceListNode* traceListHead_;

  // innermost parse context (stack-allocated)
  ParseContext* pc_;

  // For tracking used names in this parsing session.
  UsedNameTracker& usedNames_;

  RootedScriptSourceObject sourceObject_;

  // Root atoms and objects allocated for the parsed tree.
  AutoKeepAtoms keepAtoms_;

 private:
  // This is needed to cast a parser to JS::AutoGCRooter.
  friend void js::frontend::TraceParser(JSTracer* trc,
                                        JS::AutoGCRooter* parser);

#if defined(JS_BUILD_BINAST)
  friend void js::frontend::TraceBinASTParser(JSTracer* trc,
                                              JS::AutoGCRooter* parser);
#endif  // JS_BUILD_BINAST

 private:
  // Create a new traceable node and store it into the trace list.
  template <typename BoxT, typename ArgT>
  BoxT* newTraceListNode(ArgT* arg);

 public:
  // Create a new JSObject and store it into the trace list.
  ObjectBox* newObjectBox(JSObject* obj);

  // Create a new BigInt and store it into the trace list.
  BigIntBox* newBigIntBox(BigInt* val);
};

class MOZ_STACK_CLASS ParserBase : public ParserSharedBase,
                                   public ErrorReportMixin {
  using Base = ErrorReportMixin;

 private:
  ParserBase* thisForCtor() { return this; }

 public:
  TokenStreamAnyChars anyChars;

  ScriptSource* ss;

  // Perform constant-folding; must be true when interfacing with the emitter.
  const bool foldConstants_ : 1;

 protected:
#if DEBUG
  /* Our fallible 'checkOptions' member function has been called. */
  bool checkOptionsCalled_ : 1;
#endif

  /* Unexpected end of input, i.e. Eof not at top-level. */
  bool isUnexpectedEOF_ : 1;

  /* AwaitHandling */ uint8_t awaitHandling_ : 2;

  bool inParametersOfAsyncFunction_ : 1;

  /* ParseGoal */ uint8_t parseGoal_ : 1;

 public:
  bool awaitIsKeyword() const { return awaitHandling_ != AwaitIsName; }

  bool inParametersOfAsyncFunction() const {
    return inParametersOfAsyncFunction_;
  }

  ParseGoal parseGoal() const { return ParseGoal(parseGoal_); }

  template <class, typename>
  friend class AutoAwaitIsKeyword;
  template <class, typename>
  friend class AutoInParametersOfAsyncFunction;

  ParserBase(JSContext* cx, LifoAlloc& alloc,
             const JS::ReadOnlyCompileOptions& options, bool foldConstants,
             UsedNameTracker& usedNames, ScriptSourceObject* sourceObject,
             ParseGoal parseGoal);
  ~ParserBase();

  bool checkOptions();

  void trace(JSTracer* trc);

  const char* getFilename() const { return anyChars.getFilename(); }
  TokenPos pos() const { return anyChars.currentToken().pos; }

  // Determine whether |yield| is a valid name in the current context.
  bool yieldExpressionsSupported() const { return pc_->isGenerator(); }

  bool setLocalStrictMode(bool strict) {
    MOZ_ASSERT(anyChars.debugHasNoLookahead());
    return pc_->sc()->setLocalStrictMode(strict);
  }

 public:
  // Implement ErrorReportMixin.

  JSContext* getContext() const override { return cx_; }

  bool strictMode() const override { return pc_->sc()->strict(); }

  const JS::ReadOnlyCompileOptions& options() const override {
    return anyChars.options();
  }

  using Base::error;
  using Base::errorAt;
  using Base::errorNoOffset;
  using Base::errorWithNotes;
  using Base::errorWithNotesAt;
  using Base::errorWithNotesNoOffset;
  using Base::extraWarning;
  using Base::extraWarningAt;
  using Base::extraWarningNoOffset;
  using Base::extraWarningWithNotes;
  using Base::extraWarningWithNotesAt;
  using Base::extraWarningWithNotesNoOffset;
  using Base::strictModeError;
  using Base::strictModeErrorAt;
  using Base::strictModeErrorNoOffset;
  using Base::strictModeErrorWithNotes;
  using Base::strictModeErrorWithNotesAt;
  using Base::strictModeErrorWithNotesNoOffset;
  using Base::warning;
  using Base::warningAt;
  using Base::warningNoOffset;
  using Base::warningWithNotes;
  using Base::warningWithNotesAt;
  using Base::warningWithNotesNoOffset;

 public:
  bool isUnexpectedEOF() const { return isUnexpectedEOF_; }

  bool isValidStrictBinding(PropertyName* name);

  bool hasValidSimpleStrictParameterNames();

  /*
   * Create a new function object given a name (which is optional if this is
   * a function expression).
   */
  JSFunction* newFunction(HandleAtom atom, FunctionSyntaxKind kind,
                          GeneratorKind generatorKind,
                          FunctionAsyncKind asyncKind,
                          HandleObject proto = nullptr);

  // A Parser::Mark is the extension of the LifoAlloc::Mark to the entire
  // Parser's state. Note: clients must still take care that any ParseContext
  // that points into released ParseNodes is destroyed.
  class Mark {
    friend class ParserBase;
    LifoAlloc::Mark mark;
    TraceListNode* traceListHead;
  };
  Mark mark() const {
    Mark m;
    m.mark = alloc_.mark();
    m.traceListHead = traceListHead_;
    return m;
  }
  void release(Mark m) {
    alloc_.release(m.mark);
    traceListHead_ = m.traceListHead;
  }

 public:
  mozilla::Maybe<GlobalScope::Data*> newGlobalScopeData(
      ParseContext::Scope& scope);
  mozilla::Maybe<ModuleScope::Data*> newModuleScopeData(
      ParseContext::Scope& scope);
  mozilla::Maybe<EvalScope::Data*> newEvalScopeData(ParseContext::Scope& scope);
  mozilla::Maybe<FunctionScope::Data*> newFunctionScopeData(
      ParseContext::Scope& scope, bool hasParameterExprs,
      IsFieldInitializer isFieldInitializer);
  mozilla::Maybe<VarScope::Data*> newVarScopeData(ParseContext::Scope& scope);
  mozilla::Maybe<LexicalScope::Data*> newLexicalScopeData(
      ParseContext::Scope& scope);

 protected:
  enum InvokedPrediction { PredictUninvoked = false, PredictInvoked = true };
  enum ForInitLocation { InForInit, NotInForInit };

  // While on a |let| Name token, examine |next| (which must already be
  // gotten).  Indicate whether |next|, the next token already gotten with
  // modifier TokenStream::SlashIsDiv, continues a LexicalDeclaration.
  bool nextTokenContinuesLetDeclaration(TokenKind next);

  bool noteUsedNameInternal(HandlePropertyName name);

  bool checkAndMarkSuperScope();

  bool leaveInnerFunction(ParseContext* outerpc);

  JSAtom* prefixAccessorName(PropertyType propType, HandleAtom propAtom);

  MOZ_MUST_USE bool setSourceMapInfo();

  void setFunctionEndFromCurrentToken(FunctionBox* funbox) const;
};

enum FunctionCallBehavior {
  PermitAssignmentToFunctionCalls,
  ForbidAssignmentToFunctionCalls
};

template <class ParseHandler>
class MOZ_STACK_CLASS PerHandlerParser : public ParserBase {
  using Base = ParserBase;

 private:
  using Node = typename ParseHandler::Node;

#define DECLARE_TYPE(typeName, longTypeName, asMethodName) \
  using longTypeName = typename ParseHandler::longTypeName;
  FOR_EACH_PARSENODE_SUBCLASS(DECLARE_TYPE)
#undef DECLARE_TYPE

 protected:
  /* State specific to the kind of parse being performed. */
  ParseHandler handler_;

  // When ParseHandler is FullParseHandler:
  //
  //   If non-null, this field holds the syntax parser used to attempt lazy
  //   parsing of inner functions. If null, then lazy parsing is disabled.
  //
  // When ParseHandler is SyntaxParseHandler:
  //
  //   If non-null, this field must be a sentinel value signaling that the
  //   syntax parse was aborted. If null, then lazy parsing was aborted due
  //   to encountering unsupported language constructs.
  //
  // |internalSyntaxParser_| is really a |Parser<SyntaxParseHandler, Unit>*|
  // where |Unit| varies per |Parser<ParseHandler, Unit>|.  But this
  // template class doesn't know |Unit|, so we store a |void*| here and make
  // |GeneralParser<ParseHandler, Unit>::getSyntaxParser| impose the real type.
  void* internalSyntaxParser_;

 private:
  // NOTE: The argument ordering here is deliberately different from the
  //       public constructor so that typos calling the public constructor
  //       are less likely to select this overload.
  PerHandlerParser(JSContext* cx, LifoAlloc& alloc,
                   const JS::ReadOnlyCompileOptions& options,
                   bool foldConstants, UsedNameTracker& usedNames,
                   LazyScript* lazyOuterFunction,
                   ScriptSourceObject* sourceObject, ParseGoal parseGoal,
                   void* internalSyntaxParser);

 protected:
  template <typename Unit>
  PerHandlerParser(JSContext* cx, LifoAlloc& alloc,
                   const JS::ReadOnlyCompileOptions& options,
                   bool foldConstants, UsedNameTracker& usedNames,
                   GeneralParser<SyntaxParseHandler, Unit>* syntaxParser,
                   LazyScript* lazyOuterFunction,
                   ScriptSourceObject* sourceObject, ParseGoal parseGoal)
      : PerHandlerParser(
            cx, alloc, options, foldConstants, usedNames, lazyOuterFunction,
            sourceObject, parseGoal,
            // JSOPTION_EXTRA_WARNINGS adds extra warnings not
            // generated when functions are parsed lazily.
            // ("use strict" doesn't inhibit lazy parsing.)
            static_cast<void*>(options.extraWarningsOption ? nullptr
                                                           : syntaxParser)) {}

  static typename ParseHandler::NullNode null() { return ParseHandler::null(); }

  NameNodeType stringLiteral();

  const char* nameIsArgumentsOrEval(Node node);

  bool noteDestructuredPositionalFormalParameter(FunctionNodeType funNode,
                                                 Node destruct);

  bool noteUsedName(HandlePropertyName name) {
    // If the we are delazifying, the LazyScript already has all the
    // closed-over info for bindings and there's no need to track used
    // names.
    if (handler_.canSkipLazyClosedOverBindings()) {
      return true;
    }

    return ParserBase::noteUsedNameInternal(name);
  }

  // Required on Scope exit.
  bool propagateFreeNamesAndMarkClosedOverBindings(ParseContext::Scope& scope);

  bool finishFunctionScopes(bool isStandaloneFunction);
  LexicalScopeNodeType finishLexicalScope(ParseContext::Scope& scope,
                                          Node body);
  bool finishFunction(
      bool isStandaloneFunction = false,
      IsFieldInitializer isFieldInitializer = IsFieldInitializer::No);

  inline NameNodeType newName(PropertyName* name);
  inline NameNodeType newName(PropertyName* name, TokenPos pos);

  NameNodeType newInternalDotName(HandlePropertyName name);
  NameNodeType newThisName();
  NameNodeType newDotGeneratorName();

  NameNodeType identifierReference(Handle<PropertyName*> name);

  Node noSubstitutionTaggedTemplate();

  inline bool processExport(Node node);
  inline bool processExportFrom(BinaryNodeType node);

  // If ParseHandler is SyntaxParseHandler:
  //   Do nothing.
  // If ParseHandler is FullParseHandler:
  //   Disable syntax parsing of all future inner functions during this
  //   full-parse.
  inline void disableSyntaxParser();

  // If ParseHandler is SyntaxParseHandler:
  //   Flag the current syntax parse as aborted due to unsupported language
  //   constructs and return false.  Aborting the current syntax parse does
  //   not disable attempts to syntax-parse future inner functions.
  // If ParseHandler is FullParseHandler:
  //    Disable syntax parsing of all future inner functions and return true.
  inline bool abortIfSyntaxParser();

  // If ParseHandler is SyntaxParseHandler:
  //   Return whether the last syntax parse was aborted due to unsupported
  //   language constructs.
  // If ParseHandler is FullParseHandler:
  //   Return false.
  inline bool hadAbortedSyntaxParse();

  // If ParseHandler is SyntaxParseHandler:
  //   Clear whether the last syntax parse was aborted.
  // If ParseHandler is FullParseHandler:
  //   Do nothing.
  inline void clearAbortedSyntaxParse();

 public:
  bool isValidSimpleAssignmentTarget(
      Node node,
      FunctionCallBehavior behavior = ForbidAssignmentToFunctionCalls);

  NameNodeType newPropertyName(PropertyName* key, const TokenPos& pos) {
    return handler_.newPropertyName(key, pos);
  }

  PropertyAccessType newPropertyAccess(Node expr, NameNodeType key) {
    return handler_.newPropertyAccess(expr, key);
  }

  FunctionBox* newFunctionBox(FunctionNodeType funNode, JSFunction* fun,
                              uint32_t toStringStart, Directives directives,
                              GeneratorKind generatorKind,
                              FunctionAsyncKind asyncKind);

 public:
  // ErrorReportMixin.

  using Base::error;
  using Base::errorAt;
  using Base::errorNoOffset;
  using Base::errorWithNotes;
  using Base::errorWithNotesAt;
  using Base::errorWithNotesNoOffset;
  using Base::extraWarning;
  using Base::extraWarningAt;
  using Base::extraWarningNoOffset;
  using Base::extraWarningWithNotes;
  using Base::extraWarningWithNotesAt;
  using Base::extraWarningWithNotesNoOffset;
  using Base::strictModeError;
  using Base::strictModeErrorAt;
  using Base::strictModeErrorNoOffset;
  using Base::strictModeErrorWithNotes;
  using Base::strictModeErrorWithNotesAt;
  using Base::strictModeErrorWithNotesNoOffset;
  using Base::warning;
  using Base::warningAt;
  using Base::warningNoOffset;
  using Base::warningWithNotes;
  using Base::warningWithNotesAt;
  using Base::warningWithNotesNoOffset;
};

#define ABORTED_SYNTAX_PARSE_SENTINEL reinterpret_cast<void*>(0x1)

template <>
inline void PerHandlerParser<SyntaxParseHandler>::disableSyntaxParser() {}

template <>
inline bool PerHandlerParser<SyntaxParseHandler>::abortIfSyntaxParser() {
  internalSyntaxParser_ = ABORTED_SYNTAX_PARSE_SENTINEL;
  return false;
}

template <>
inline bool PerHandlerParser<SyntaxParseHandler>::hadAbortedSyntaxParse() {
  return internalSyntaxParser_ == ABORTED_SYNTAX_PARSE_SENTINEL;
}

template <>
inline void PerHandlerParser<SyntaxParseHandler>::clearAbortedSyntaxParse() {
  internalSyntaxParser_ = nullptr;
}

#undef ABORTED_SYNTAX_PARSE_SENTINEL

// Disable syntax parsing of all future inner functions during this
// full-parse.
template <>
inline void PerHandlerParser<FullParseHandler>::disableSyntaxParser() {
  internalSyntaxParser_ = nullptr;
}

template <>
inline bool PerHandlerParser<FullParseHandler>::abortIfSyntaxParser() {
  disableSyntaxParser();
  return true;
}

template <>
inline bool PerHandlerParser<FullParseHandler>::hadAbortedSyntaxParse() {
  return false;
}

template <>
inline void PerHandlerParser<FullParseHandler>::clearAbortedSyntaxParse() {}

template <class Parser>
class ParserAnyCharsAccess {
 public:
  using TokenStreamSpecific = typename Parser::TokenStream;
  using GeneralTokenStreamChars =
      typename TokenStreamSpecific::GeneralCharsBase;

  static inline TokenStreamAnyChars& anyChars(GeneralTokenStreamChars* ts);
  static inline const TokenStreamAnyChars& anyChars(
      const GeneralTokenStreamChars* ts);
};

// Specify a value for an ES6 grammar parametrization.  We have no enum for
// [Return] because its behavior is exactly equivalent to checking whether
// we're in a function box -- easier and simpler than passing an extra
// parameter everywhere.
enum YieldHandling { YieldIsName, YieldIsKeyword };
enum InHandling { InAllowed, InProhibited };
enum DefaultHandling { NameRequired, AllowDefaultName };
enum TripledotHandling { TripledotAllowed, TripledotProhibited };

template <class ParseHandler, typename Unit>
class Parser;

template <class ParseHandler, typename Unit>
class MOZ_STACK_CLASS GeneralParser : public PerHandlerParser<ParseHandler> {
 public:
  using TokenStream =
      TokenStreamSpecific<Unit, ParserAnyCharsAccess<GeneralParser>>;

 private:
  using Base = PerHandlerParser<ParseHandler>;
  using FinalParser = Parser<ParseHandler, Unit>;
  using Node = typename ParseHandler::Node;

#define DECLARE_TYPE(typeName, longTypeName, asMethodName) \
  using longTypeName = typename ParseHandler::longTypeName;
  FOR_EACH_PARSENODE_SUBCLASS(DECLARE_TYPE)
#undef DECLARE_TYPE

  using typename Base::InvokedPrediction;
  using SyntaxParser = Parser<SyntaxParseHandler, Unit>;

 protected:
  using Modifier = TokenStreamShared::Modifier;
  using Position = typename TokenStream::Position;

  using Base::PredictInvoked;
  using Base::PredictUninvoked;

  using Base::alloc_;
  using Base::awaitIsKeyword;
  using Base::inParametersOfAsyncFunction;
  using Base::parseGoal;
#if DEBUG
  using Base::checkOptionsCalled_;
#endif
  using Base::finishFunctionScopes;
  using Base::finishLexicalScope;
  using Base::foldConstants_;
  using Base::getFilename;
  using Base::hasValidSimpleStrictParameterNames;
  using Base::isUnexpectedEOF_;
  using Base::keepAtoms_;
  using Base::nameIsArgumentsOrEval;
  using Base::newFunction;
  using Base::newFunctionBox;
  using Base::newName;
  using Base::null;
  using Base::options;
  using Base::pos;
  using Base::propagateFreeNamesAndMarkClosedOverBindings;
  using Base::setLocalStrictMode;
  using Base::stringLiteral;
  using Base::traceListHead_;
  using Base::yieldExpressionsSupported;

  using Base::abortIfSyntaxParser;
  using Base::clearAbortedSyntaxParse;
  using Base::disableSyntaxParser;
  using Base::hadAbortedSyntaxParse;

 public:
  // Implement ErrorReportMixin.

  MOZ_MUST_USE bool computeErrorMetadata(
      ErrorMetadata* err, const ErrorReportMixin::ErrorOffset& offset) override;

  using Base::error;
  using Base::errorAt;
  using Base::errorNoOffset;
  using Base::errorWithNotes;
  using Base::errorWithNotesAt;
  using Base::errorWithNotesNoOffset;
  using Base::extraWarning;
  using Base::extraWarningAt;
  using Base::extraWarningNoOffset;
  using Base::extraWarningWithNotes;
  using Base::extraWarningWithNotesAt;
  using Base::extraWarningWithNotesNoOffset;
  using Base::strictModeError;
  using Base::strictModeErrorAt;
  using Base::strictModeErrorNoOffset;
  using Base::strictModeErrorWithNotes;
  using Base::strictModeErrorWithNotesAt;
  using Base::strictModeErrorWithNotesNoOffset;
  using Base::warning;
  using Base::warningAt;
  using Base::warningNoOffset;
  using Base::warningWithNotes;
  using Base::warningWithNotesAt;
  using Base::warningWithNotesNoOffset;

 public:
  using Base::anyChars;
  using Base::cx_;
  using Base::handler_;
  using Base::isValidSimpleAssignmentTarget;
  using Base::pc_;
  using Base::usedNames_;

 private:
  using Base::checkAndMarkSuperScope;
  using Base::finishFunction;
  using Base::identifierReference;
  using Base::leaveInnerFunction;
  using Base::newDotGeneratorName;
  using Base::newInternalDotName;
  using Base::newThisName;
  using Base::nextTokenContinuesLetDeclaration;
  using Base::noSubstitutionTaggedTemplate;
  using Base::noteDestructuredPositionalFormalParameter;
  using Base::noteUsedName;
  using Base::prefixAccessorName;
  using Base::processExport;
  using Base::processExportFrom;
  using Base::setFunctionEndFromCurrentToken;

 private:
  inline FinalParser* asFinalParser();
  inline const FinalParser* asFinalParser() const;

  /*
   * A class for temporarily stashing errors while parsing continues.
   *
   * The ability to stash an error is useful for handling situations where we
   * aren't able to verify that an error has occurred until later in the parse.
   * For instance | ({x=1}) | is always parsed as an object literal with
   * a SyntaxError, however, in the case where it is followed by '=>' we rewind
   * and reparse it as a valid arrow function. Here a PossibleError would be
   * set to 'pending' when the initial SyntaxError was encountered then
   * 'resolved' just before rewinding the parser.
   *
   * There are currently two kinds of PossibleErrors: Expression and
   * Destructuring errors. Expression errors are used to mark a possible
   * syntax error when a grammar production is used in an expression context.
   * For example in |{x = 1}|, we mark the CoverInitializedName |x = 1| as a
   * possible expression error, because CoverInitializedName productions
   * are disallowed when an actual ObjectLiteral is expected.
   * Destructuring errors are used to record possible syntax errors in
   * destructuring contexts. For example in |[...rest, ] = []|, we initially
   * mark the trailing comma after the spread expression as a possible
   * destructuring error, because the ArrayAssignmentPattern grammar
   * production doesn't allow a trailing comma after the rest element.
   *
   * When using PossibleError one should set a pending error at the location
   * where an error occurs. From that point, the error may be resolved
   * (invalidated) or left until the PossibleError is checked.
   *
   * Ex:
   *   PossibleError possibleError(*this);
   *   possibleError.setPendingExpressionErrorAt(pos, JSMSG_BAD_PROP_ID);
   *   // A JSMSG_BAD_PROP_ID ParseError is reported, returns false.
   *   if (!possibleError.checkForExpressionError()) {
   *       return false; // we reach this point with a pending exception
   *   }
   *
   *   PossibleError possibleError(*this);
   *   possibleError.setPendingExpressionErrorAt(pos, JSMSG_BAD_PROP_ID);
   *   // Returns true, no error is reported.
   *   if (!possibleError.checkForDestructuringError()) {
   *       return false; // not reached, no pending exception
   *   }
   *
   *   PossibleError possibleError(*this);
   *   // Returns true, no error is reported.
   *   if (!possibleError.checkForExpressionError()) {
   *       return false; // not reached, no pending exception
   *   }
   */
  class MOZ_STACK_CLASS PossibleError {
   private:
    enum class ErrorKind { Expression, Destructuring, DestructuringWarning };

    enum class ErrorState { None, Pending };

    struct Error {
      ErrorState state_ = ErrorState::None;

      // Error reporting fields.
      uint32_t offset_;
      unsigned errorNumber_;
    };

    GeneralParser<ParseHandler, Unit>& parser_;
    Error exprError_;
    Error destructuringError_;
    Error destructuringWarning_;

    // Returns the error report.
    Error& error(ErrorKind kind);

    // Return true if an error is pending without reporting.
    bool hasError(ErrorKind kind);

    // Resolve any pending error.
    void setResolved(ErrorKind kind);

    // Set a pending error. Only a single error may be set per instance and
    // error kind.
    void setPending(ErrorKind kind, const TokenPos& pos, unsigned errorNumber);

    // If there is a pending error, report it and return false, otherwise
    // return true.
    MOZ_MUST_USE bool checkForError(ErrorKind kind);

    // If there is a pending warning, report it and return either false or
    // true depending on the werror option, otherwise return true.
    MOZ_MUST_USE bool checkForWarning(ErrorKind kind);

    // Transfer an existing error to another instance.
    void transferErrorTo(ErrorKind kind, PossibleError* other);

   public:
    explicit PossibleError(GeneralParser<ParseHandler, Unit>& parser);

    // Return true if a pending destructuring error is present.
    bool hasPendingDestructuringError();

    // Set a pending destructuring error. Only a single error may be set
    // per instance, i.e. subsequent calls to this method are ignored and
    // won't overwrite the existing pending error.
    void setPendingDestructuringErrorAt(const TokenPos& pos,
                                        unsigned errorNumber);

    // Set a pending destructuring warning. Only a single warning may be
    // set per instance, i.e. subsequent calls to this method are ignored
    // and won't overwrite the existing pending warning.
    void setPendingDestructuringWarningAt(const TokenPos& pos,
                                          unsigned errorNumber);

    // Set a pending expression error. Only a single error may be set per
    // instance, i.e. subsequent calls to this method are ignored and won't
    // overwrite the existing pending error.
    void setPendingExpressionErrorAt(const TokenPos& pos, unsigned errorNumber);

    // If there is a pending destructuring error or warning, report it and
    // return false, otherwise return true. Clears any pending expression
    // error.
    MOZ_MUST_USE bool checkForDestructuringErrorOrWarning();

    // If there is a pending expression error, report it and return false,
    // otherwise return true. Clears any pending destructuring error or
    // warning.
    MOZ_MUST_USE bool checkForExpressionError();

    // Pass pending errors between possible error instances. This is useful
    // for extending the lifetime of a pending error beyond the scope of
    // the PossibleError where it was initially set (keeping in mind that
    // PossibleError is a MOZ_STACK_CLASS).
    void transferErrorsTo(PossibleError* other);
  };

 protected:
  SyntaxParser* getSyntaxParser() const {
    return reinterpret_cast<SyntaxParser*>(Base::internalSyntaxParser_);
  }

 public:
  TokenStream tokenStream;

 public:
  GeneralParser(JSContext* cx, LifoAlloc& alloc,
                const JS::ReadOnlyCompileOptions& options, const Unit* units,
                size_t length, bool foldConstants, UsedNameTracker& usedNames,
                SyntaxParser* syntaxParser, LazyScript* lazyOuterFunction,
                ScriptSourceObject* sourceObject, ParseGoal parseGoal);

  inline void setAwaitHandling(AwaitHandling awaitHandling);
  inline void setInParametersOfAsyncFunction(bool inParameters);

  /*
   * Parse a top-level JS script.
   */
  ListNodeType parse();

 private:
  /*
   * Gets the next token and checks if it matches to the given `condition`.
   * If it matches, returns true.
   * If it doesn't match, calls `errorReport` to report the error, and
   * returns false.
   * If other error happens, it returns false but `errorReport` may not be
   * called and other error will be thrown in that case.
   *
   * In any case, the already gotten token is not ungotten.
   *
   * The signature of `condition` is [...](TokenKind actual) -> bool, and
   * the signature of `errorReport` is [...](TokenKind actual).
   */
  template <typename ConditionT, typename ErrorReportT>
  MOZ_MUST_USE bool mustMatchTokenInternal(ConditionT condition,
                                           ErrorReportT errorReport);

 public:
  /*
   * The following mustMatchToken variants follow the behavior and parameter
   * types of mustMatchTokenInternal above.
   *
   * If modifier is omitted, `SlashIsDiv` is used.
   * If TokenKind is passed instead of `condition`, it checks if the next
   * token is the passed token.
   * If error number is passed instead of `errorReport`, it reports an
   * error with the passed errorNumber.
   */
  MOZ_MUST_USE bool mustMatchToken(TokenKind expected, JSErrNum errorNumber) {
    return mustMatchTokenInternal(
        [expected](TokenKind actual) { return actual == expected; },
        [this, errorNumber](TokenKind) { this->error(errorNumber); });
  }

  template <typename ConditionT>
  MOZ_MUST_USE bool mustMatchToken(ConditionT condition, JSErrNum errorNumber) {
    return mustMatchTokenInternal(condition, [this, errorNumber](TokenKind) {
      this->error(errorNumber);
    });
  }

  template <typename ErrorReportT>
  MOZ_MUST_USE bool mustMatchToken(TokenKind expected,
                                   ErrorReportT errorReport) {
    return mustMatchTokenInternal(
        [expected](TokenKind actual) { return actual == expected; },
        errorReport);
  }

 private:
  GeneralParser* thisForCtor() { return this; }

  NameNodeType noSubstitutionUntaggedTemplate();
  ListNodeType templateLiteral(YieldHandling yieldHandling);
  bool taggedTemplate(YieldHandling yieldHandling, ListNodeType tagArgsList,
                      TokenKind tt);
  bool appendToCallSiteObj(CallSiteNodeType callSiteObj);
  bool addExprAndGetNextTemplStrToken(YieldHandling yieldHandling,
                                      ListNodeType nodeList, TokenKind* ttp);

  inline bool trySyntaxParseInnerFunction(
      FunctionNodeType* funNode, HandleFunction fun, uint32_t toStringStart,
      InHandling inHandling, YieldHandling yieldHandling,
      FunctionSyntaxKind kind, GeneratorKind generatorKind,
      FunctionAsyncKind asyncKind, bool tryAnnexB,
      Directives inheritedDirectives, Directives* newDirectives);

  inline bool skipLazyInnerFunction(FunctionNodeType funNode,
                                    uint32_t toStringStart,
                                    FunctionSyntaxKind kind, bool tryAnnexB);

  void setFunctionStartAtCurrentToken(FunctionBox* funbox) const;

 public:
  /* Public entry points for parsing. */
  Node statementListItem(YieldHandling yieldHandling,
                         bool canHaveDirectives = false);

  // Parse an inner function given an enclosing ParseContext and a
  // FunctionBox for the inner function.
  MOZ_MUST_USE FunctionNodeType innerFunctionForFunctionBox(
      FunctionNodeType funNode, ParseContext* outerpc, FunctionBox* funbox,
      InHandling inHandling, YieldHandling yieldHandling,
      FunctionSyntaxKind kind, Directives* newDirectives);

  // Parse a function's formal parameters and its body assuming its function
  // ParseContext is already on the stack.
  bool functionFormalParametersAndBody(
      InHandling inHandling, YieldHandling yieldHandling,
      FunctionNodeType* funNode, FunctionSyntaxKind kind,
      const mozilla::Maybe<uint32_t>& parameterListEnd = mozilla::Nothing(),
      bool isStandaloneFunction = false);

 private:
  /*
   * JS parsers, from lowest to highest precedence.
   *
   * Each parser must be called during the dynamic scope of a ParseContext
   * object, pointed to by this->pc_.
   *
   * Each returns a parse node tree or null on error.
   */
  FunctionNodeType functionStmt(
      uint32_t toStringStart, YieldHandling yieldHandling,
      DefaultHandling defaultHandling,
      FunctionAsyncKind asyncKind = FunctionAsyncKind::SyncFunction);
  FunctionNodeType functionExpr(uint32_t toStringStart,
                                InvokedPrediction invoked,
                                FunctionAsyncKind asyncKind);

  Node statement(YieldHandling yieldHandling);
  bool maybeParseDirective(ListNodeType list, Node pn, bool* cont);

  LexicalScopeNodeType blockStatement(
      YieldHandling yieldHandling,
      unsigned errorNumber = JSMSG_CURLY_IN_COMPOUND);
  BinaryNodeType doWhileStatement(YieldHandling yieldHandling);
  BinaryNodeType whileStatement(YieldHandling yieldHandling);

  Node forStatement(YieldHandling yieldHandling);
  bool forHeadStart(YieldHandling yieldHandling, ParseNodeKind* forHeadKind,
                    Node* forInitialPart,
                    mozilla::Maybe<ParseContext::Scope>& forLetImpliedScope,
                    Node* forInOrOfExpression);
  Node expressionAfterForInOrOf(ParseNodeKind forHeadKind,
                                YieldHandling yieldHandling);

  SwitchStatementType switchStatement(YieldHandling yieldHandling);
  ContinueStatementType continueStatement(YieldHandling yieldHandling);
  BreakStatementType breakStatement(YieldHandling yieldHandling);
  UnaryNodeType returnStatement(YieldHandling yieldHandling);
  BinaryNodeType withStatement(YieldHandling yieldHandling);
  UnaryNodeType throwStatement(YieldHandling yieldHandling);
  TernaryNodeType tryStatement(YieldHandling yieldHandling);
  LexicalScopeNodeType catchBlockStatement(
      YieldHandling yieldHandling, ParseContext::Scope& catchParamScope);
  DebuggerStatementType debuggerStatement();

  ListNodeType variableStatement(YieldHandling yieldHandling);

  LabeledStatementType labeledStatement(YieldHandling yieldHandling);
  Node labeledItem(YieldHandling yieldHandling);

  TernaryNodeType ifStatement(YieldHandling yieldHandling);
  Node consequentOrAlternative(YieldHandling yieldHandling);

  ListNodeType lexicalDeclaration(YieldHandling yieldHandling,
                                  DeclarationKind kind);

  inline BinaryNodeType importDeclaration();
  Node importDeclarationOrImportExpr(YieldHandling yieldHandling);

  BinaryNodeType exportFrom(uint32_t begin, Node specList);
  BinaryNodeType exportBatch(uint32_t begin);
  inline bool checkLocalExportNames(ListNodeType node);
  Node exportClause(uint32_t begin);
  UnaryNodeType exportFunctionDeclaration(
      uint32_t begin, uint32_t toStringStart,
      FunctionAsyncKind asyncKind = FunctionAsyncKind::SyncFunction);
  UnaryNodeType exportVariableStatement(uint32_t begin);
  UnaryNodeType exportClassDeclaration(uint32_t begin);
  UnaryNodeType exportLexicalDeclaration(uint32_t begin, DeclarationKind kind);
  BinaryNodeType exportDefaultFunctionDeclaration(
      uint32_t begin, uint32_t toStringStart,
      FunctionAsyncKind asyncKind = FunctionAsyncKind::SyncFunction);
  BinaryNodeType exportDefaultClassDeclaration(uint32_t begin);
  BinaryNodeType exportDefaultAssignExpr(uint32_t begin);
  BinaryNodeType exportDefault(uint32_t begin);
  Node exportDeclaration();

  UnaryNodeType expressionStatement(
      YieldHandling yieldHandling,
      InvokedPrediction invoked = PredictUninvoked);

  // Declaration parsing.  The main entrypoint is Parser::declarationList,
  // with sub-functionality split out into the remaining methods.

  // |blockScope| may be non-null only when |kind| corresponds to a lexical
  // declaration (that is, PNK_LET or PNK_CONST).
  //
  // The for* parameters, for normal declarations, should be null/ignored.
  // They should be non-null only when Parser::forHeadStart parses a
  // declaration at the start of a for-loop head.
  //
  // In this case, on success |*forHeadKind| is PNK_FORHEAD, PNK_FORIN, or
  // PNK_FOROF, corresponding to the three for-loop kinds.  The precise value
  // indicates what was parsed.
  //
  // If parsing recognized a for(;;) loop, the next token is the ';' within
  // the loop-head that separates the init/test parts.
  //
  // Otherwise, for for-in/of loops, the next token is the ')' ending the
  // loop-head.  Additionally, the expression that the loop iterates over was
  // parsed into |*forInOrOfExpression|.
  ListNodeType declarationList(YieldHandling yieldHandling, ParseNodeKind kind,
                               ParseNodeKind* forHeadKind = nullptr,
                               Node* forInOrOfExpression = nullptr);

  // The items in a declaration list are either patterns or names, with or
  // without initializers.  These two methods parse a single pattern/name and
  // any associated initializer -- and if parsing an |initialDeclaration|
  // will, if parsing in a for-loop head (as specified by |forHeadKind| being
  // non-null), consume additional tokens up to the closing ')' in a
  // for-in/of loop head, returning the iterated expression in
  // |*forInOrOfExpression|.  (An "initial declaration" is the first
  // declaration in a declaration list: |a| but not |b| in |var a, b|, |{c}|
  // but not |d| in |let {c} = 3, d|.)
  Node declarationPattern(DeclarationKind declKind, TokenKind tt,
                          bool initialDeclaration, YieldHandling yieldHandling,
                          ParseNodeKind* forHeadKind,
                          Node* forInOrOfExpression);
  Node declarationName(DeclarationKind declKind, TokenKind tt,
                       bool initialDeclaration, YieldHandling yieldHandling,
                       ParseNodeKind* forHeadKind, Node* forInOrOfExpression);

  // Having parsed a name (not found in a destructuring pattern) declared by
  // a declaration, with the current token being the '=' separating the name
  // from its initializer, parse and bind that initializer -- and possibly
  // consume trailing in/of and subsequent expression, if so directed by
  // |forHeadKind|.
  AssignmentNodeType initializerInNameDeclaration(NameNodeType binding,
                                                  DeclarationKind declKind,
                                                  bool initialDeclaration,
                                                  YieldHandling yieldHandling,
                                                  ParseNodeKind* forHeadKind,
                                                  Node* forInOrOfExpression);

  Node expr(InHandling inHandling, YieldHandling yieldHandling,
            TripledotHandling tripledotHandling,
            PossibleError* possibleError = nullptr,
            InvokedPrediction invoked = PredictUninvoked);
  Node assignExpr(InHandling inHandling, YieldHandling yieldHandling,
                  TripledotHandling tripledotHandling,
                  PossibleError* possibleError = nullptr,
                  InvokedPrediction invoked = PredictUninvoked);
  Node assignExprWithoutYieldOrAwait(YieldHandling yieldHandling);
  UnaryNodeType yieldExpression(InHandling inHandling);
  Node condExpr(InHandling inHandling, YieldHandling yieldHandling,
                TripledotHandling tripledotHandling,
                PossibleError* possibleError,
                InvokedPrediction invoked = PredictUninvoked);
  Node orExpr(InHandling inHandling, YieldHandling yieldHandling,
              TripledotHandling tripledotHandling, PossibleError* possibleError,
              InvokedPrediction invoked = PredictUninvoked);
  Node unaryExpr(YieldHandling yieldHandling,
                 TripledotHandling tripledotHandling,
                 PossibleError* possibleError = nullptr,
                 InvokedPrediction invoked = PredictUninvoked);
  Node memberExpr(YieldHandling yieldHandling,
                  TripledotHandling tripledotHandling, TokenKind tt,
                  bool allowCallSyntax = true,
                  PossibleError* possibleError = nullptr,
                  InvokedPrediction invoked = PredictUninvoked);
  Node primaryExpr(YieldHandling yieldHandling,
                   TripledotHandling tripledotHandling, TokenKind tt,
                   PossibleError* possibleError,
                   InvokedPrediction invoked = PredictUninvoked);
  Node exprInParens(InHandling inHandling, YieldHandling yieldHandling,
                    TripledotHandling tripledotHandling,
                    PossibleError* possibleError = nullptr);

  bool tryNewTarget(BinaryNodeType* newTarget);

  BinaryNodeType importExpr(YieldHandling yieldHandling, bool allowCallSyntax);

  FunctionNodeType methodDefinition(uint32_t toStringStart,
                                    PropertyType propType, HandleAtom funName);

  /*
   * Additional JS parsers.
   */
  bool functionArguments(YieldHandling yieldHandling, FunctionSyntaxKind kind,
                         FunctionNodeType funNode);

  FunctionNodeType functionDefinition(
      FunctionNodeType funNode, uint32_t toStringStart, InHandling inHandling,
      YieldHandling yieldHandling, HandleAtom name, FunctionSyntaxKind kind,
      GeneratorKind generatorKind, FunctionAsyncKind asyncKind,
      bool tryAnnexB = false);

  // Parse a function body.  Pass StatementListBody if the body is a list of
  // statements; pass ExpressionBody if the body is a single expression.
  enum FunctionBodyType { StatementListBody, ExpressionBody };
  LexicalScopeNodeType functionBody(InHandling inHandling,
                                    YieldHandling yieldHandling,
                                    FunctionSyntaxKind kind,
                                    FunctionBodyType type);

  UnaryNodeType unaryOpExpr(YieldHandling yieldHandling, ParseNodeKind kind,
                            uint32_t begin);

  Node condition(InHandling inHandling, YieldHandling yieldHandling);

  ListNodeType argumentList(YieldHandling yieldHandling, bool* isSpread,
                            PossibleError* possibleError = nullptr);
  Node destructuringDeclaration(DeclarationKind kind,
                                YieldHandling yieldHandling, TokenKind tt);
  Node destructuringDeclarationWithoutYieldOrAwait(DeclarationKind kind,
                                                   YieldHandling yieldHandling,
                                                   TokenKind tt);

  inline bool checkExportedName(JSAtom* exportName);
  inline bool checkExportedNamesForArrayBinding(ListNodeType array);
  inline bool checkExportedNamesForObjectBinding(ListNodeType obj);
  inline bool checkExportedNamesForDeclaration(Node node);
  inline bool checkExportedNamesForDeclarationList(ListNodeType node);
  inline bool checkExportedNameForFunction(FunctionNodeType funNode);
  inline bool checkExportedNameForClass(ClassNodeType classNode);
  inline bool checkExportedNameForClause(NameNodeType nameNode);

  enum ClassContext { ClassStatement, ClassExpression };
  ClassNodeType classDefinition(YieldHandling yieldHandling,
                                ClassContext classContext,
                                DefaultHandling defaultHandling);
  MOZ_MUST_USE bool classMember(
      YieldHandling yieldHandling, DefaultHandling defaultHandling,
      const ParseContext::ClassStatement& classStmt,
      HandlePropertyName className, uint32_t classStartOffset,
      HasHeritage hasHeritage, size_t& numFieldsWithInitializers,
      size_t& numFieldKeys, ListNodeType& classMembers, bool* done);
  MOZ_MUST_USE bool finishClassConstructor(
      const ParseContext::ClassStatement& classStmt,
      HandlePropertyName className, HasHeritage hasHeritage,
      uint32_t classStartOffset, uint32_t classEndOffset,
      size_t numFieldsWithInitializers, ListNodeType& classMembers);

  FunctionNodeType fieldInitializerOpt(YieldHandling yieldHandling,
                                       HasHeritage hasHeritage, Node name,
                                       HandleAtom atom, size_t& numFieldKeys);
  FunctionNodeType synthesizeConstructor(HandleAtom className,
                                         uint32_t classNameOffset,
                                         HasHeritage hasHeritage);

  bool checkBindingIdentifier(PropertyName* ident, uint32_t offset,
                              YieldHandling yieldHandling,
                              TokenKind hint = TokenKind::Limit);

  PropertyName* labelOrIdentifierReference(YieldHandling yieldHandling);

  PropertyName* labelIdentifier(YieldHandling yieldHandling) {
    return labelOrIdentifierReference(yieldHandling);
  }

  PropertyName* identifierReference(YieldHandling yieldHandling) {
    return labelOrIdentifierReference(yieldHandling);
  }

  bool matchLabel(YieldHandling yieldHandling,
                  MutableHandle<PropertyName*> label);

  // Indicate if the next token (tokenized with SlashIsRegExp) is |in| or |of|.
  // If so, consume it.
  bool matchInOrOf(bool* isForInp, bool* isForOfp);

 private:
  bool checkIncDecOperand(Node operand, uint32_t operandOffset);
  bool checkStrictAssignment(Node lhs);

  void reportMissingClosing(unsigned errorNumber, unsigned noteNumber,
                            uint32_t openedPos);

  void reportRedeclaration(HandlePropertyName name, DeclarationKind prevKind,
                           TokenPos pos, uint32_t prevPos);
  bool notePositionalFormalParameter(FunctionNodeType funNode,
                                     HandlePropertyName name, uint32_t beginPos,
                                     bool disallowDuplicateParams,
                                     bool* duplicatedParam);

  bool checkLexicalDeclarationDirectlyWithinBlock(ParseContext::Statement& stmt,
                                                  DeclarationKind kind,
                                                  TokenPos pos);

  enum PropertyNameContext {
    PropertyNameInLiteral,
    PropertyNameInPattern,
    PropertyNameInClass
  };
  Node propertyName(YieldHandling yieldHandling,
                    PropertyNameContext propertyNameContext,
                    const mozilla::Maybe<DeclarationKind>& maybeDecl,
                    ListNodeType propList, MutableHandleAtom propAtom);
  Node propertyOrMethodName(YieldHandling yieldHandling,
                            PropertyNameContext propertyNameContext,
                            const mozilla::Maybe<DeclarationKind>& maybeDecl,
                            ListNodeType propList, PropertyType* propType,
                            MutableHandleAtom propAtom);
  UnaryNodeType computedPropertyName(
      YieldHandling yieldHandling,
      const mozilla::Maybe<DeclarationKind>& maybeDecl,
      PropertyNameContext propertyNameContext, ListNodeType literal);
  ListNodeType arrayInitializer(YieldHandling yieldHandling,
                                PossibleError* possibleError);
  inline RegExpLiteralType newRegExp();

  ListNodeType objectLiteral(YieldHandling yieldHandling,
                             PossibleError* possibleError);

  BinaryNodeType bindingInitializer(Node lhs, DeclarationKind kind,
                                    YieldHandling yieldHandling);
  NameNodeType bindingIdentifier(DeclarationKind kind,
                                 YieldHandling yieldHandling);
  Node bindingIdentifierOrPattern(DeclarationKind kind,
                                  YieldHandling yieldHandling, TokenKind tt);
  ListNodeType objectBindingPattern(DeclarationKind kind,
                                    YieldHandling yieldHandling);
  ListNodeType arrayBindingPattern(DeclarationKind kind,
                                   YieldHandling yieldHandling);

  enum class TargetBehavior {
    PermitAssignmentPattern,
    ForbidAssignmentPattern
  };
  bool checkDestructuringAssignmentTarget(
      Node expr, TokenPos exprPos, PossibleError* exprPossibleError,
      PossibleError* possibleError,
      TargetBehavior behavior = TargetBehavior::PermitAssignmentPattern);
  void checkDestructuringAssignmentName(NameNodeType name, TokenPos namePos,
                                        PossibleError* possibleError);
  bool checkDestructuringAssignmentElement(Node expr, TokenPos exprPos,
                                           PossibleError* exprPossibleError,
                                           PossibleError* possibleError);

  NumericLiteralType newNumber(const Token& tok) {
    return handler_.newNumber(tok.number(), tok.decimalPoint(), tok.pos);
  }

  inline BigIntLiteralType newBigInt();

 protected:
  // Match the current token against the BindingIdentifier production with
  // the given Yield parameter.  If there is no match, report a syntax
  // error.
  PropertyName* bindingIdentifier(YieldHandling yieldHandling);

  bool checkLabelOrIdentifierReference(PropertyName* ident, uint32_t offset,
                                       YieldHandling yieldHandling,
                                       TokenKind hint = TokenKind::Limit);

  ListNodeType statementList(YieldHandling yieldHandling);

  MOZ_MUST_USE FunctionNodeType innerFunction(
      FunctionNodeType funNode, ParseContext* outerpc, HandleFunction fun,
      uint32_t toStringStart, InHandling inHandling,
      YieldHandling yieldHandling, FunctionSyntaxKind kind,
      GeneratorKind generatorKind, FunctionAsyncKind asyncKind, bool tryAnnexB,
      Directives inheritedDirectives, Directives* newDirectives);

  // Implements Automatic Semicolon Insertion.
  //
  // Use this to match `;` in contexts where ASI is allowed. Call this after
  // ruling out all other possibilities except `;`, by peeking ahead if
  // necessary.
  //
  // Unlike most optional Modifiers, this method's `modifier` argument defaults
  // to SlashIsRegExp, since that's by far the most common case: usually an
  // optional semicolon is at the end of a statement or declaration, and the
  // next token could be a RegExp literal beginning a new ExpressionStatement.
  bool matchOrInsertSemicolon(Modifier modifier = TokenStream::SlashIsRegExp);

  bool noteDeclaredName(HandlePropertyName name, DeclarationKind kind,
                        TokenPos pos);

 private:
  inline bool asmJS(ListNodeType list);
};

template <typename Unit>
class MOZ_STACK_CLASS Parser<SyntaxParseHandler, Unit> final
    : public GeneralParser<SyntaxParseHandler, Unit> {
  using Base = GeneralParser<SyntaxParseHandler, Unit>;
  using Node = SyntaxParseHandler::Node;

#define DECLARE_TYPE(typeName, longTypeName, asMethodName) \
  using longTypeName = SyntaxParseHandler::longTypeName;
  FOR_EACH_PARSENODE_SUBCLASS(DECLARE_TYPE)
#undef DECLARE_TYPE

  using SyntaxParser = Parser<SyntaxParseHandler, Unit>;

  // Numerous Base::* functions have bodies like
  //
  //   return asFinalParser()->func(...);
  //
  // and must be able to call functions here.  Add a friendship relationship
  // so functions here can be hidden when appropriate.
  friend class GeneralParser<SyntaxParseHandler, Unit>;

 public:
  using Base::Base;

  // Inherited types, listed here to have non-dependent names.
  using typename Base::Modifier;
  using typename Base::Position;
  using typename Base::TokenStream;

  // Inherited functions, listed here to have non-dependent names.

 public:
  using Base::anyChars;
  using Base::clearAbortedSyntaxParse;
  using Base::cx_;
  using Base::hadAbortedSyntaxParse;
  using Base::innerFunctionForFunctionBox;
  using Base::tokenStream;

 public:
  // ErrorReportMixin.

  using Base::error;
  using Base::errorAt;
  using Base::errorNoOffset;
  using Base::errorWithNotes;
  using Base::errorWithNotesAt;
  using Base::errorWithNotesNoOffset;
  using Base::extraWarning;
  using Base::extraWarningAt;
  using Base::extraWarningNoOffset;
  using Base::extraWarningWithNotes;
  using Base::extraWarningWithNotesAt;
  using Base::extraWarningWithNotesNoOffset;
  using Base::strictModeError;
  using Base::strictModeErrorAt;
  using Base::strictModeErrorNoOffset;
  using Base::strictModeErrorWithNotes;
  using Base::strictModeErrorWithNotesAt;
  using Base::strictModeErrorWithNotesNoOffset;
  using Base::warning;
  using Base::warningAt;
  using Base::warningNoOffset;
  using Base::warningWithNotes;
  using Base::warningWithNotesAt;
  using Base::warningWithNotesNoOffset;

 private:
  using Base::alloc_;
#if DEBUG
  using Base::checkOptionsCalled_;
#endif
  using Base::finishFunctionScopes;
  using Base::functionFormalParametersAndBody;
  using Base::handler_;
  using Base::innerFunction;
  using Base::keepAtoms_;
  using Base::matchOrInsertSemicolon;
  using Base::mustMatchToken;
  using Base::newFunctionBox;
  using Base::newLexicalScopeData;
  using Base::newModuleScopeData;
  using Base::newName;
  using Base::noteDeclaredName;
  using Base::null;
  using Base::options;
  using Base::pc_;
  using Base::pos;
  using Base::propagateFreeNamesAndMarkClosedOverBindings;
  using Base::ss;
  using Base::statementList;
  using Base::stringLiteral;
  using Base::usedNames_;

 private:
  using Base::abortIfSyntaxParser;
  using Base::disableSyntaxParser;

 public:
  // Functions with multiple overloads of different visibility.  We can't
  // |using| the whole thing into existence because of the visibility
  // distinction, so we instead must manually delegate the required overload.

  PropertyName* bindingIdentifier(YieldHandling yieldHandling) {
    return Base::bindingIdentifier(yieldHandling);
  }

  // Functions present in both Parser<ParseHandler, Unit> specializations.

  inline void setAwaitHandling(AwaitHandling awaitHandling);
  inline void setInParametersOfAsyncFunction(bool inParameters);

  RegExpLiteralType newRegExp();
  BigIntLiteralType newBigInt();

  // Parse a module.
  ModuleNodeType moduleBody(ModuleSharedContext* modulesc);

  inline BinaryNodeType importDeclaration();
  inline bool checkLocalExportNames(ListNodeType node);
  inline bool checkExportedName(JSAtom* exportName);
  inline bool checkExportedNamesForArrayBinding(ListNodeType array);
  inline bool checkExportedNamesForObjectBinding(ListNodeType obj);
  inline bool checkExportedNamesForDeclaration(Node node);
  inline bool checkExportedNamesForDeclarationList(ListNodeType node);
  inline bool checkExportedNameForFunction(FunctionNodeType funNode);
  inline bool checkExportedNameForClass(ClassNodeType classNode);
  inline bool checkExportedNameForClause(NameNodeType nameNode);

  bool trySyntaxParseInnerFunction(
      FunctionNodeType* funNode, HandleFunction fun, uint32_t toStringStart,
      InHandling inHandling, YieldHandling yieldHandling,
      FunctionSyntaxKind kind, GeneratorKind generatorKind,
      FunctionAsyncKind asyncKind, bool tryAnnexB,
      Directives inheritedDirectives, Directives* newDirectives);

  bool skipLazyInnerFunction(FunctionNodeType funNode, uint32_t toStringStart,
                             FunctionSyntaxKind kind, bool tryAnnexB);

  bool asmJS(ListNodeType list);

  // Functions present only in Parser<SyntaxParseHandler, Unit>.
};

template <typename Unit>
class MOZ_STACK_CLASS Parser<FullParseHandler, Unit> final
    : public GeneralParser<FullParseHandler, Unit> {
  using Base = GeneralParser<FullParseHandler, Unit>;
  using Node = FullParseHandler::Node;

#define DECLARE_TYPE(typeName, longTypeName, asMethodName) \
  using longTypeName = FullParseHandler::longTypeName;
  FOR_EACH_PARSENODE_SUBCLASS(DECLARE_TYPE)
#undef DECLARE_TYPE

  using SyntaxParser = Parser<SyntaxParseHandler, Unit>;

  // Numerous Base::* functions have bodies like
  //
  //   return asFinalParser()->func(...);
  //
  // and must be able to call functions here.  Add a friendship relationship
  // so functions here can be hidden when appropriate.
  friend class GeneralParser<FullParseHandler, Unit>;

 public:
  using Base::Base;

  // Inherited types, listed here to have non-dependent names.
  using typename Base::Modifier;
  using typename Base::Position;
  using typename Base::TokenStream;

  // Inherited functions, listed here to have non-dependent names.

 public:
  using Base::anyChars;
  using Base::clearAbortedSyntaxParse;
  using Base::functionFormalParametersAndBody;
  using Base::hadAbortedSyntaxParse;
  using Base::handler_;
  using Base::newFunctionBox;
  using Base::options;
  using Base::pc_;
  using Base::pos;
  using Base::ss;
  using Base::tokenStream;

 public:
  // ErrorReportMixin.

  using Base::error;
  using Base::errorAt;
  using Base::errorNoOffset;
  using Base::errorWithNotes;
  using Base::errorWithNotesAt;
  using Base::errorWithNotesNoOffset;
  using Base::extraWarning;
  using Base::extraWarningAt;
  using Base::extraWarningNoOffset;
  using Base::extraWarningWithNotes;
  using Base::extraWarningWithNotesAt;
  using Base::extraWarningWithNotesNoOffset;
  using Base::strictModeError;
  using Base::strictModeErrorAt;
  using Base::strictModeErrorNoOffset;
  using Base::strictModeErrorWithNotes;
  using Base::strictModeErrorWithNotesAt;
  using Base::strictModeErrorWithNotesNoOffset;
  using Base::warning;
  using Base::warningAt;
  using Base::warningNoOffset;
  using Base::warningWithNotes;
  using Base::warningWithNotesAt;
  using Base::warningWithNotesNoOffset;

 private:
  using Base::alloc_;
  using Base::checkLabelOrIdentifierReference;
#if DEBUG
  using Base::checkOptionsCalled_;
#endif
  using Base::cx_;
  using Base::finishFunctionScopes;
  using Base::finishLexicalScope;
  using Base::innerFunction;
  using Base::innerFunctionForFunctionBox;
  using Base::keepAtoms_;
  using Base::matchOrInsertSemicolon;
  using Base::mustMatchToken;
  using Base::newEvalScopeData;
  using Base::newFunctionScopeData;
  using Base::newGlobalScopeData;
  using Base::newLexicalScopeData;
  using Base::newModuleScopeData;
  using Base::newName;
  using Base::newVarScopeData;
  using Base::noteDeclaredName;
  using Base::null;
  using Base::propagateFreeNamesAndMarkClosedOverBindings;
  using Base::statementList;
  using Base::stringLiteral;
  using Base::usedNames_;

  using Base::abortIfSyntaxParser;
  using Base::disableSyntaxParser;
  using Base::getSyntaxParser;

 public:
  // Functions with multiple overloads of different visibility.  We can't
  // |using| the whole thing into existence because of the visibility
  // distinction, so we instead must manually delegate the required overload.

  PropertyName* bindingIdentifier(YieldHandling yieldHandling) {
    return Base::bindingIdentifier(yieldHandling);
  }

  // Functions present in both Parser<ParseHandler, Unit> specializations.

  friend class AutoAwaitIsKeyword<SyntaxParseHandler, Unit>;
  inline void setAwaitHandling(AwaitHandling awaitHandling);

  friend class AutoInParametersOfAsyncFunction<SyntaxParseHandler, Unit>;
  inline void setInParametersOfAsyncFunction(bool inParameters);

  RegExpLiteralType newRegExp();
  BigIntLiteralType newBigInt();

  // Parse a module.
  ModuleNodeType moduleBody(ModuleSharedContext* modulesc);

  BinaryNodeType importDeclaration();
  bool checkLocalExportNames(ListNodeType node);
  bool checkExportedName(JSAtom* exportName);
  bool checkExportedNamesForArrayBinding(ListNodeType array);
  bool checkExportedNamesForObjectBinding(ListNodeType obj);
  bool checkExportedNamesForDeclaration(Node node);
  bool checkExportedNamesForDeclarationList(ListNodeType node);
  bool checkExportedNameForFunction(FunctionNodeType funNode);
  bool checkExportedNameForClass(ClassNodeType classNode);
  inline bool checkExportedNameForClause(NameNodeType nameNode);

  bool trySyntaxParseInnerFunction(
      FunctionNodeType* funNode, HandleFunction fun, uint32_t toStringStart,
      InHandling inHandling, YieldHandling yieldHandling,
      FunctionSyntaxKind kind, GeneratorKind generatorKind,
      FunctionAsyncKind asyncKind, bool tryAnnexB,
      Directives inheritedDirectives, Directives* newDirectives);

  bool skipLazyInnerFunction(FunctionNodeType funNode, uint32_t toStringStart,
                             FunctionSyntaxKind kind, bool tryAnnexB);

  // Functions present only in Parser<FullParseHandler, Unit>.

  // Parse the body of an eval.
  //
  // Eval scripts are distinguished from global scripts in that in ES6, per
  // 18.2.1.1 steps 9 and 10, all eval scripts are executed under a fresh
  // lexical scope.
  LexicalScopeNodeType evalBody(EvalSharedContext* evalsc);

  // Parse a function, given only its arguments and body. Used for lazily
  // parsed functions.
  FunctionNodeType standaloneLazyFunction(HandleFunction fun,
                                          uint32_t toStringStart, bool strict,
                                          GeneratorKind generatorKind,
                                          FunctionAsyncKind asyncKind);

  // Parse a function, used for the Function, GeneratorFunction, and
  // AsyncFunction constructors.
  FunctionNodeType standaloneFunction(
      HandleFunction fun, HandleScope enclosingScope,
      const mozilla::Maybe<uint32_t>& parameterListEnd,
      GeneratorKind generatorKind, FunctionAsyncKind asyncKind,
      Directives inheritedDirectives, Directives* newDirectives);

  bool checkStatementsEOF();

  // Parse the body of a global script.
  ListNodeType globalBody(GlobalSharedContext* globalsc);

  bool namedImportsOrNamespaceImport(TokenKind tt, ListNodeType importSpecSet);

  PropertyName* importedBinding() { return bindingIdentifier(YieldIsName); }

  bool checkLocalExportName(PropertyName* ident, uint32_t offset) {
    return checkLabelOrIdentifierReference(ident, offset, YieldIsName);
  }

  bool asmJS(ListNodeType list);
};

template <class Parser>
/* static */ inline const TokenStreamAnyChars&
ParserAnyCharsAccess<Parser>::anyChars(const GeneralTokenStreamChars* ts) {
  // The structure we're walking through looks like this:
  //
  //   struct ParserBase
  //   {
  //       ...;
  //       TokenStreamAnyChars anyChars;
  //       ...;
  //   };
  //   struct Parser : <class that ultimately inherits from ParserBase>
  //   {
  //       ...;
  //       TokenStreamSpecific tokenStream;
  //       ...;
  //   };
  //
  // We're passed a GeneralTokenStreamChars* (this being a base class of
  // Parser::tokenStream).  We cast that pointer to a TokenStreamSpecific*,
  // then translate that to the enclosing Parser*, then return the |anyChars|
  // member within.

  static_assert(
      mozilla::IsBaseOf<GeneralTokenStreamChars, TokenStreamSpecific>::value,
      "the static_cast<> below assumes a base-class relationship");
  const auto* tss = static_cast<const TokenStreamSpecific*>(ts);

  auto tssAddr = reinterpret_cast<uintptr_t>(tss);

  using ActualTokenStreamType =
      decltype(static_cast<Parser*>(nullptr)->tokenStream);
  static_assert(
      mozilla::IsSame<ActualTokenStreamType, TokenStreamSpecific>::value,
      "Parser::tokenStream must have type TokenStreamSpecific");

  uintptr_t parserAddr = tssAddr - offsetof(Parser, tokenStream);

  return reinterpret_cast<const Parser*>(parserAddr)->anyChars;
}

template <class Parser>
/* static */ inline TokenStreamAnyChars& ParserAnyCharsAccess<Parser>::anyChars(
    GeneralTokenStreamChars* ts) {
  const TokenStreamAnyChars& anyCharsConst =
      anyChars(const_cast<const GeneralTokenStreamChars*>(ts));

  return const_cast<TokenStreamAnyChars&>(anyCharsConst);
}

template <class ParseHandler, typename Unit>
class MOZ_STACK_CLASS AutoAwaitIsKeyword {
  using GeneralParser = frontend::GeneralParser<ParseHandler, Unit>;

 private:
  GeneralParser* parser_;
  AwaitHandling oldAwaitHandling_;

 public:
  AutoAwaitIsKeyword(GeneralParser* parser, AwaitHandling awaitHandling) {
    parser_ = parser;
    oldAwaitHandling_ = static_cast<AwaitHandling>(parser_->awaitHandling_);

    // 'await' is always a keyword in module contexts, so we don't modify
    // the state when the original handling is AwaitIsModuleKeyword.
    if (oldAwaitHandling_ != AwaitIsModuleKeyword) {
      parser_->setAwaitHandling(awaitHandling);
    }
  }

  ~AutoAwaitIsKeyword() { parser_->setAwaitHandling(oldAwaitHandling_); }
};

template <class ParseHandler, typename Unit>
class MOZ_STACK_CLASS AutoInParametersOfAsyncFunction {
  using GeneralParser = frontend::GeneralParser<ParseHandler, Unit>;

 private:
  GeneralParser* parser_;
  bool oldInParametersOfAsyncFunction_;

 public:
  AutoInParametersOfAsyncFunction(GeneralParser* parser, bool inParameters) {
    parser_ = parser;
    oldInParametersOfAsyncFunction_ = parser_->inParametersOfAsyncFunction_;
    parser_->setInParametersOfAsyncFunction(inParameters);
  }

  ~AutoInParametersOfAsyncFunction() {
    parser_->setInParametersOfAsyncFunction(oldInParametersOfAsyncFunction_);
  }
};

template <typename Scope>
extern typename Scope::Data* NewEmptyBindingData(JSContext* cx,
                                                 LifoAlloc& alloc,
                                                 uint32_t numBindings);

mozilla::Maybe<GlobalScope::Data*> NewGlobalScopeData(
    JSContext* context, ParseContext::Scope& scope, LifoAlloc& alloc,
    ParseContext* pc);
mozilla::Maybe<EvalScope::Data*> NewEvalScopeData(JSContext* context,
                                                  ParseContext::Scope& scope,
                                                  LifoAlloc& alloc,
                                                  ParseContext* pc);
mozilla::Maybe<FunctionScope::Data*> NewFunctionScopeData(
    JSContext* context, ParseContext::Scope& scope, bool hasParameterExprs,
    IsFieldInitializer isFieldInitializer, LifoAlloc& alloc, ParseContext* pc);
mozilla::Maybe<VarScope::Data*> NewVarScopeData(JSContext* context,
                                                ParseContext::Scope& scope,
                                                LifoAlloc& alloc,
                                                ParseContext* pc);
mozilla::Maybe<LexicalScope::Data*> NewLexicalScopeData(
    JSContext* context, ParseContext::Scope& scope, LifoAlloc& alloc,
    ParseContext* pc);

JSFunction* AllocNewFunction(JSContext* cx, HandleAtom atom,
                             FunctionSyntaxKind kind,
                             GeneratorKind generatorKind,
                             FunctionAsyncKind asyncKind, HandleObject proto,
                             bool isSelfHosting = false,
                             bool inFunctionBox = false);

} /* namespace frontend */
} /* namespace js */

#endif /* frontend_Parser_h */