text: //===--- ParseDecl.cpp - Declaration Parsing --------------------*- C++ -*-===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  //  This file implements the Declaration portions of the Parser interfaces.
  //
  //===----------------------------------------------------------------------===//
  
  #include "clang/Parse/Parser.h"
  #include "clang/Parse/RAIIObjectsForParser.h"
  #include "clang/AST/ASTContext.h"
  #include "clang/AST/DeclTemplate.h"
  #include "clang/AST/PrettyDeclStackTrace.h"
  #include "clang/Basic/AddressSpaces.h"
  #include "clang/Basic/Attributes.h"
  #include "clang/Basic/CharInfo.h"
  #include "clang/Basic/TargetInfo.h"
  #include "clang/Parse/ParseDiagnostic.h"
  #include "clang/Sema/Lookup.h"
  #include "clang/Sema/ParsedTemplate.h"
  #include "clang/Sema/Scope.h"
  #include "llvm/ADT/Optional.h"
  #include "llvm/ADT/SmallSet.h"
  #include "llvm/ADT/SmallString.h"
  #include "llvm/ADT/StringSwitch.h"
  
  using namespace clang;
  
  //===----------------------------------------------------------------------===//
  // C99 6.7: Declarations.
  //===----------------------------------------------------------------------===//
  
  /// ParseTypeName
  ///       type-name: [C99 6.7.6]
  ///         specifier-qualifier-list abstract-declarator[opt]
  ///
  /// Called type-id in C++.
  TypeResult Parser::ParseTypeName(SourceRange *Range,
                                   DeclaratorContext Context,
                                   AccessSpecifier AS,
                                   Decl **OwnedType,
                                   ParsedAttributes *Attrs) {
    DeclSpecContext DSC = getDeclSpecContextFromDeclaratorContext(Context);
    if (DSC == DeclSpecContext::DSC_normal)
      DSC = DeclSpecContext::DSC_type_specifier;
  
    // Parse the common declaration-specifiers piece.
    DeclSpec DS(AttrFactory);
    if (Attrs)
      DS.addAttributes(*Attrs);
    ParseSpecifierQualifierList(DS, AS, DSC);
    if (OwnedType)
      *OwnedType = DS.isTypeSpecOwned() ? DS.getRepAsDecl() : nullptr;
  
    // Parse the abstract-declarator, if present.
    Declarator DeclaratorInfo(DS, Context);
    ParseDeclarator(DeclaratorInfo);
    if (Range)
      *Range = DeclaratorInfo.getSourceRange();
  
    if (DeclaratorInfo.isInvalidType())
      return true;
  
    return Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
  }
  
  /// Normalizes an attribute name by dropping prefixed and suffixed __.
  static StringRef normalizeAttrName(StringRef Name) {
    if (Name.size() >= 4 && Name.startswith("__") && Name.endswith("__"))
      return Name.drop_front(2).drop_back(2);
    return Name;
  }
  
  /// isAttributeLateParsed - Return true if the attribute has arguments that
  /// require late parsing.
  static bool isAttributeLateParsed(const IdentifierInfo &II) {
  #define CLANG_ATTR_LATE_PARSED_LIST
      return llvm::StringSwitch<bool>(normalizeAttrName(II.getName()))
  #include "clang/Parse/AttrParserStringSwitches.inc"
          .Default(false);
  #undef CLANG_ATTR_LATE_PARSED_LIST
  }
  
  /// Check if the a start and end source location expand to the same macro.
  bool FindLocsWithCommonFileID(Preprocessor &PP, SourceLocation StartLoc,
                                SourceLocation EndLoc) {
    if (!StartLoc.isMacroID() || !EndLoc.isMacroID())
      return false;
  
    SourceManager &SM = PP.getSourceManager();
    if (SM.getFileID(StartLoc) != SM.getFileID(EndLoc))
      return false;
  
    bool AttrStartIsInMacro =
        Lexer::isAtStartOfMacroExpansion(StartLoc, SM, PP.getLangOpts());
    bool AttrEndIsInMacro =
        Lexer::isAtEndOfMacroExpansion(EndLoc, SM, PP.getLangOpts());
    return AttrStartIsInMacro && AttrEndIsInMacro;
  }
  
  /// ParseGNUAttributes - Parse a non-empty attributes list.
  ///
  /// [GNU] attributes:
  ///         attribute
  ///         attributes attribute
  ///
  /// [GNU]  attribute:
  ///          '__attribute__' '(' '(' attribute-list ')' ')'
  ///
  /// [GNU]  attribute-list:
  ///          attrib
  ///          attribute_list ',' attrib
  ///
  /// [GNU]  attrib:
  ///          empty
  ///          attrib-name
  ///          attrib-name '(' identifier ')'
  ///          attrib-name '(' identifier ',' nonempty-expr-list ')'
  ///          attrib-name '(' argument-expression-list [C99 6.5.2] ')'
  ///
  /// [GNU]  attrib-name:
  ///          identifier
  ///          typespec
  ///          typequal
  ///          storageclass
  ///
  /// Whether an attribute takes an 'identifier' is determined by the
  /// attrib-name. GCC's behavior here is not worth imitating:
  ///
  ///  * In C mode, if the attribute argument list starts with an identifier
  ///    followed by a ',' or an ')', and the identifier doesn't resolve to
  ///    a type, it is parsed as an identifier. If the attribute actually
  ///    wanted an expression, it's out of luck (but it turns out that no
  ///    attributes work that way, because C constant expressions are very
  ///    limited).
  ///  * In C++ mode, if the attribute argument list starts with an identifier,
  ///    and the attribute *wants* an identifier, it is parsed as an identifier.
  ///    At block scope, any additional tokens between the identifier and the
  ///    ',' or ')' are ignored, otherwise they produce a parse error.
  ///
  /// We follow the C++ model, but don't allow junk after the identifier.
  void Parser::ParseGNUAttributes(ParsedAttributes &attrs,
                                  SourceLocation *endLoc,
                                  LateParsedAttrList *LateAttrs,
                                  Declarator *D) {
    assert(Tok.is(tok::kw___attribute) && "Not a GNU attribute list!");
  
    while (Tok.is(tok::kw___attribute)) {
      SourceLocation AttrTokLoc = ConsumeToken();
      unsigned OldNumAttrs = attrs.size();
      unsigned OldNumLateAttrs = LateAttrs ? LateAttrs->size() : 0;
  
      if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen_after,
                           "attribute")) {
        SkipUntil(tok::r_paren, StopAtSemi); // skip until ) or ;
        return;
      }
      if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen_after, "(")) {
        SkipUntil(tok::r_paren, StopAtSemi); // skip until ) or ;
        return;
      }
      // Parse the attribute-list. e.g. __attribute__(( weak, alias("__f") ))
      do {
        // Eat preceeding commas to allow __attribute__((,,,foo))
        while (TryConsumeToken(tok::comma))
          ;
  
        // Expect an identifier or declaration specifier (const, int, etc.)
        if (Tok.isAnnotation())
          break;
        IdentifierInfo *AttrName = Tok.getIdentifierInfo();
        if (!AttrName)
          break;
  
        SourceLocation AttrNameLoc = ConsumeToken();
  
        if (Tok.isNot(tok::l_paren)) {
          attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                       ParsedAttr::AS_GNU);
          continue;
        }
  
        // Handle "parameterized" attributes
        if (!LateAttrs || !isAttributeLateParsed(*AttrName)) {
          ParseGNUAttributeArgs(AttrName, AttrNameLoc, attrs, endLoc, nullptr,
                                SourceLocation(), ParsedAttr::AS_GNU, D);
          continue;
        }
  
        // Handle attributes with arguments that require late parsing.
        LateParsedAttribute *LA =
            new LateParsedAttribute(this, *AttrName, AttrNameLoc);
        LateAttrs->push_back(LA);
  
        // Attributes in a class are parsed at the end of the class, along
        // with other late-parsed declarations.
        if (!ClassStack.empty() && !LateAttrs->parseSoon())
          getCurrentClass().LateParsedDeclarations.push_back(LA);
  
        // Be sure ConsumeAndStoreUntil doesn't see the start l_paren, since it
        // recursively consumes balanced parens.
        LA->Toks.push_back(Tok);
        ConsumeParen();
        // Consume everything up to and including the matching right parens.
        ConsumeAndStoreUntil(tok::r_paren, LA->Toks, /*StopAtSemi=*/true);
  
        Token Eof;
        Eof.startToken();
        Eof.setLocation(Tok.getLocation());
        LA->Toks.push_back(Eof);
      } while (Tok.is(tok::comma));
  
      if (ExpectAndConsume(tok::r_paren))
        SkipUntil(tok::r_paren, StopAtSemi);
      SourceLocation Loc = Tok.getLocation();
      if (ExpectAndConsume(tok::r_paren))
        SkipUntil(tok::r_paren, StopAtSemi);
      if (endLoc)
        *endLoc = Loc;
  
      // If this was declared in a macro, attach the macro IdentifierInfo to the
      // parsed attribute.
      auto &SM = PP.getSourceManager();
      if (!SM.isWrittenInBuiltinFile(SM.getSpellingLoc(AttrTokLoc)) &&
          FindLocsWithCommonFileID(PP, AttrTokLoc, Loc)) {
        CharSourceRange ExpansionRange = SM.getExpansionRange(AttrTokLoc);
        StringRef FoundName =
            Lexer::getSourceText(ExpansionRange, SM, PP.getLangOpts());
        IdentifierInfo *MacroII = PP.getIdentifierInfo(FoundName);
  
        for (unsigned i = OldNumAttrs; i < attrs.size(); ++i)
          attrs[i].setMacroIdentifier(MacroII, ExpansionRange.getBegin());
  
        if (LateAttrs) {
          for (unsigned i = OldNumLateAttrs; i < LateAttrs->size(); ++i)
            (*LateAttrs)[i]->MacroII = MacroII;
        }
      }
    }
  }
  
  /// Determine whether the given attribute has an identifier argument.
  static bool attributeHasIdentifierArg(const IdentifierInfo &II) {
  #define CLANG_ATTR_IDENTIFIER_ARG_LIST
    return llvm::StringSwitch<bool>(normalizeAttrName(II.getName()))
  #include "clang/Parse/AttrParserStringSwitches.inc"
             .Default(false);
  #undef CLANG_ATTR_IDENTIFIER_ARG_LIST
  }
  
  /// Determine whether the given attribute has a variadic identifier argument.
  static bool attributeHasVariadicIdentifierArg(const IdentifierInfo &II) {
  #define CLANG_ATTR_VARIADIC_IDENTIFIER_ARG_LIST
    return llvm::StringSwitch<bool>(normalizeAttrName(II.getName()))
  #include "clang/Parse/AttrParserStringSwitches.inc"
             .Default(false);
  #undef CLANG_ATTR_VARIADIC_IDENTIFIER_ARG_LIST
  }
  
  /// Determine whether the given attribute treats kw_this as an identifier.
  static bool attributeTreatsKeywordThisAsIdentifier(const IdentifierInfo &II) {
  #define CLANG_ATTR_THIS_ISA_IDENTIFIER_ARG_LIST
    return llvm::StringSwitch<bool>(normalizeAttrName(II.getName()))
  #include "clang/Parse/AttrParserStringSwitches.inc"
             .Default(false);
  #undef CLANG_ATTR_THIS_ISA_IDENTIFIER_ARG_LIST
  }
  
  /// Determine whether the given attribute parses a type argument.
  static bool attributeIsTypeArgAttr(const IdentifierInfo &II) {
  #define CLANG_ATTR_TYPE_ARG_LIST
    return llvm::StringSwitch<bool>(normalizeAttrName(II.getName()))
  #include "clang/Parse/AttrParserStringSwitches.inc"
             .Default(false);
  #undef CLANG_ATTR_TYPE_ARG_LIST
  }
  
  /// Determine whether the given attribute requires parsing its arguments
  /// in an unevaluated context or not.
  static bool attributeParsedArgsUnevaluated(const IdentifierInfo &II) {
  #define CLANG_ATTR_ARG_CONTEXT_LIST
    return llvm::StringSwitch<bool>(normalizeAttrName(II.getName()))
  #include "clang/Parse/AttrParserStringSwitches.inc"
             .Default(false);
  #undef CLANG_ATTR_ARG_CONTEXT_LIST
  }
  
  IdentifierLoc *Parser::ParseIdentifierLoc() {
    assert(Tok.is(tok::identifier) && "expected an identifier");
    IdentifierLoc *IL = IdentifierLoc::create(Actions.Context,
                                              Tok.getLocation(),
                                              Tok.getIdentifierInfo());
    ConsumeToken();
    return IL;
  }
  
  void Parser::ParseAttributeWithTypeArg(IdentifierInfo &AttrName,
                                         SourceLocation AttrNameLoc,
                                         ParsedAttributes &Attrs,
                                         SourceLocation *EndLoc,
                                         IdentifierInfo *ScopeName,
                                         SourceLocation ScopeLoc,
                                         ParsedAttr::Syntax Syntax) {
    BalancedDelimiterTracker Parens(*this, tok::l_paren);
    Parens.consumeOpen();
  
    TypeResult T;
    if (Tok.isNot(tok::r_paren))
      T = ParseTypeName();
  
    if (Parens.consumeClose())
      return;
  
    if (T.isInvalid())
      return;
  
    if (T.isUsable())
      Attrs.addNewTypeAttr(&AttrName,
                           SourceRange(AttrNameLoc, Parens.getCloseLocation()),
                           ScopeName, ScopeLoc, T.get(), Syntax);
    else
      Attrs.addNew(&AttrName, SourceRange(AttrNameLoc, Parens.getCloseLocation()),
                   ScopeName, ScopeLoc, nullptr, 0, Syntax);
  }
  
  unsigned Parser::ParseAttributeArgsCommon(
      IdentifierInfo *AttrName, SourceLocation AttrNameLoc,
      ParsedAttributes &Attrs, SourceLocation *EndLoc, IdentifierInfo *ScopeName,
      SourceLocation ScopeLoc, ParsedAttr::Syntax Syntax) {
    // Ignore the left paren location for now.
    ConsumeParen();
  
    bool ChangeKWThisToIdent = attributeTreatsKeywordThisAsIdentifier(*AttrName);
  
    // Interpret "kw_this" as an identifier if the attributed requests it.
    if (ChangeKWThisToIdent && Tok.is(tok::kw_this))
      Tok.setKind(tok::identifier);
  
    ArgsVector ArgExprs;
    if (Tok.is(tok::identifier)) {
      // If this attribute wants an 'identifier' argument, make it so.
      bool IsIdentifierArg = attributeHasIdentifierArg(*AttrName) ||
                             attributeHasVariadicIdentifierArg(*AttrName);
      ParsedAttr::Kind AttrKind =
          ParsedAttr::getKind(AttrName, ScopeName, Syntax);
  
      // If we don't know how to parse this attribute, but this is the only
      // token in this argument, assume it's meant to be an identifier.
      if (AttrKind == ParsedAttr::UnknownAttribute ||
          AttrKind == ParsedAttr::IgnoredAttribute) {
        const Token &Next = NextToken();
        IsIdentifierArg = Next.isOneOf(tok::r_paren, tok::comma);
      }
  
      if (IsIdentifierArg)
        ArgExprs.push_back(ParseIdentifierLoc());
    }
  
    if (!ArgExprs.empty() ? Tok.is(tok::comma) : Tok.isNot(tok::r_paren)) {
      // Eat the comma.
      if (!ArgExprs.empty())
        ConsumeToken();
  
      // Parse the non-empty comma-separated list of expressions.
      do {
        // Interpret "kw_this" as an identifier if the attributed requests it.
        if (ChangeKWThisToIdent && Tok.is(tok::kw_this))
          Tok.setKind(tok::identifier);
  
        ExprResult ArgExpr;
        if (Tok.is(tok::identifier) &&
            attributeHasVariadicIdentifierArg(*AttrName)) {
          ArgExprs.push_back(ParseIdentifierLoc());
        } else {
          bool Uneval = attributeParsedArgsUnevaluated(*AttrName);
          EnterExpressionEvaluationContext Unevaluated(
              Actions,
              Uneval ? Sema::ExpressionEvaluationContext::Unevaluated
                     : Sema::ExpressionEvaluationContext::ConstantEvaluated);
  
          ExprResult ArgExpr(
              Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression()));
          if (ArgExpr.isInvalid()) {
            SkipUntil(tok::r_paren, StopAtSemi);
            return 0;
          }
          ArgExprs.push_back(ArgExpr.get());
        }
        // Eat the comma, move to the next argument
      } while (TryConsumeToken(tok::comma));
    }
  
    SourceLocation RParen = Tok.getLocation();
    if (!ExpectAndConsume(tok::r_paren)) {
      SourceLocation AttrLoc = ScopeLoc.isValid() ? ScopeLoc : AttrNameLoc;
      Attrs.addNew(AttrName, SourceRange(AttrLoc, RParen), ScopeName, ScopeLoc,
                   ArgExprs.data(), ArgExprs.size(), Syntax);
    }
  
    if (EndLoc)
      *EndLoc = RParen;
  
    return static_cast<unsigned>(ArgExprs.size());
  }
  
  /// Parse the arguments to a parameterized GNU attribute or
  /// a C++11 attribute in "gnu" namespace.
  void Parser::ParseGNUAttributeArgs(IdentifierInfo *AttrName,
                                     SourceLocation AttrNameLoc,
                                     ParsedAttributes &Attrs,
                                     SourceLocation *EndLoc,
                                     IdentifierInfo *ScopeName,
                                     SourceLocation ScopeLoc,
                                     ParsedAttr::Syntax Syntax,
                                     Declarator *D) {
  
    assert(Tok.is(tok::l_paren) && "Attribute arg list not starting with '('");
  
    ParsedAttr::Kind AttrKind =
        ParsedAttr::getKind(AttrName, ScopeName, Syntax);
  
    if (AttrKind == ParsedAttr::AT_Availability) {
      ParseAvailabilityAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc, ScopeName,
                                 ScopeLoc, Syntax);
      return;
    } else if (AttrKind == ParsedAttr::AT_ExternalSourceSymbol) {
      ParseExternalSourceSymbolAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc,
                                         ScopeName, ScopeLoc, Syntax);
      return;
    } else if (AttrKind == ParsedAttr::AT_ObjCBridgeRelated) {
      ParseObjCBridgeRelatedAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc,
                                      ScopeName, ScopeLoc, Syntax);
      return;
    } else if (AttrKind == ParsedAttr::AT_TypeTagForDatatype) {
      ParseTypeTagForDatatypeAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc,
                                       ScopeName, ScopeLoc, Syntax);
      return;
    } else if (attributeIsTypeArgAttr(*AttrName)) {
      ParseAttributeWithTypeArg(*AttrName, AttrNameLoc, Attrs, EndLoc, ScopeName,
                                ScopeLoc, Syntax);
      return;
    }
  
    // These may refer to the function arguments, but need to be parsed early to
    // participate in determining whether it's a redeclaration.
    llvm::Optional<ParseScope> PrototypeScope;
    if (normalizeAttrName(AttrName->getName()) == "enable_if" &&
        D && D->isFunctionDeclarator()) {
      DeclaratorChunk::FunctionTypeInfo FTI = D->getFunctionTypeInfo();
      PrototypeScope.emplace(this, Scope::FunctionPrototypeScope |
                                       Scope::FunctionDeclarationScope |
                                       Scope::DeclScope);
      for (unsigned i = 0; i != FTI.NumParams; ++i) {
        ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
        Actions.ActOnReenterCXXMethodParameter(getCurScope(), Param);
      }
    }
  
    ParseAttributeArgsCommon(AttrName, AttrNameLoc, Attrs, EndLoc, ScopeName,
                             ScopeLoc, Syntax);
  }
  
  unsigned Parser::ParseClangAttributeArgs(
      IdentifierInfo *AttrName, SourceLocation AttrNameLoc,
      ParsedAttributes &Attrs, SourceLocation *EndLoc, IdentifierInfo *ScopeName,
      SourceLocation ScopeLoc, ParsedAttr::Syntax Syntax) {
    assert(Tok.is(tok::l_paren) && "Attribute arg list not starting with '('");
  
    ParsedAttr::Kind AttrKind =
        ParsedAttr::getKind(AttrName, ScopeName, Syntax);
  
    switch (AttrKind) {
    default:
      return ParseAttributeArgsCommon(AttrName, AttrNameLoc, Attrs, EndLoc,
                                      ScopeName, ScopeLoc, Syntax);
    case ParsedAttr::AT_ExternalSourceSymbol:
      ParseExternalSourceSymbolAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc,
                                         ScopeName, ScopeLoc, Syntax);
      break;
    case ParsedAttr::AT_Availability:
      ParseAvailabilityAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc, ScopeName,
                                 ScopeLoc, Syntax);
      break;
    case ParsedAttr::AT_ObjCBridgeRelated:
      ParseObjCBridgeRelatedAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc,
                                      ScopeName, ScopeLoc, Syntax);
      break;
    case ParsedAttr::AT_TypeTagForDatatype:
      ParseTypeTagForDatatypeAttribute(*AttrName, AttrNameLoc, Attrs, EndLoc,
                                       ScopeName, ScopeLoc, Syntax);
      break;
    }
    return !Attrs.empty() ? Attrs.begin()->getNumArgs() : 0;
  }
  
  bool Parser::ParseMicrosoftDeclSpecArgs(IdentifierInfo *AttrName,
                                          SourceLocation AttrNameLoc,
                                          ParsedAttributes &Attrs) {
    // If the attribute isn't known, we will not attempt to parse any
    // arguments.
    if (!hasAttribute(AttrSyntax::Declspec, nullptr, AttrName,
                      getTargetInfo(), getLangOpts())) {
      // Eat the left paren, then skip to the ending right paren.
      ConsumeParen();
      SkipUntil(tok::r_paren);
      return false;
    }
  
    SourceLocation OpenParenLoc = Tok.getLocation();
  
    if (AttrName->getName() == "property") {
      // The property declspec is more complex in that it can take one or two
      // assignment expressions as a parameter, but the lhs of the assignment
      // must be named get or put.
  
      BalancedDelimiterTracker T(*this, tok::l_paren);
      T.expectAndConsume(diag::err_expected_lparen_after,
                         AttrName->getNameStart(), tok::r_paren);
  
      enum AccessorKind {
        AK_Invalid = -1,
        AK_Put = 0,
        AK_Get = 1 // indices into AccessorNames
      };
      IdentifierInfo *AccessorNames[] = {nullptr, nullptr};
      bool HasInvalidAccessor = false;
  
      // Parse the accessor specifications.
      while (true) {
        // Stop if this doesn't look like an accessor spec.
        if (!Tok.is(tok::identifier)) {
          // If the user wrote a completely empty list, use a special diagnostic.
          if (Tok.is(tok::r_paren) && !HasInvalidAccessor &&
              AccessorNames[AK_Put] == nullptr &&
              AccessorNames[AK_Get] == nullptr) {
            Diag(AttrNameLoc, diag::err_ms_property_no_getter_or_putter);
            break;
          }
  
          Diag(Tok.getLocation(), diag::err_ms_property_unknown_accessor);
          break;
        }
  
        AccessorKind Kind;
        SourceLocation KindLoc = Tok.getLocation();
        StringRef KindStr = Tok.getIdentifierInfo()->getName();
        if (KindStr == "get") {
          Kind = AK_Get;
        } else if (KindStr == "put") {
          Kind = AK_Put;
  
          // Recover from the common mistake of using 'set' instead of 'put'.
        } else if (KindStr == "set") {
          Diag(KindLoc, diag::err_ms_property_has_set_accessor)
              << FixItHint::CreateReplacement(KindLoc, "put");
          Kind = AK_Put;
  
          // Handle the mistake of forgetting the accessor kind by skipping
          // this accessor.
        } else if (NextToken().is(tok::comma) || NextToken().is(tok::r_paren)) {
          Diag(KindLoc, diag::err_ms_property_missing_accessor_kind);
          ConsumeToken();
          HasInvalidAccessor = true;
          goto next_property_accessor;
  
          // Otherwise, complain about the unknown accessor kind.
        } else {
          Diag(KindLoc, diag::err_ms_property_unknown_accessor);
          HasInvalidAccessor = true;
          Kind = AK_Invalid;
  
          // Try to keep parsing unless it doesn't look like an accessor spec.
          if (!NextToken().is(tok::equal))
            break;
        }
  
        // Consume the identifier.
        ConsumeToken();
  
        // Consume the '='.
        if (!TryConsumeToken(tok::equal)) {
          Diag(Tok.getLocation(), diag::err_ms_property_expected_equal)
              << KindStr;
          break;
        }
  
        // Expect the method name.
        if (!Tok.is(tok::identifier)) {
          Diag(Tok.getLocation(), diag::err_ms_property_expected_accessor_name);
          break;
        }
  
        if (Kind == AK_Invalid) {
          // Just drop invalid accessors.
        } else if (AccessorNames[Kind] != nullptr) {
          // Complain about the repeated accessor, ignore it, and keep parsing.
          Diag(KindLoc, diag::err_ms_property_duplicate_accessor) << KindStr;
        } else {
          AccessorNames[Kind] = Tok.getIdentifierInfo();
        }
        ConsumeToken();
  
      next_property_accessor:
        // Keep processing accessors until we run out.
        if (TryConsumeToken(tok::comma))
          continue;
  
        // If we run into the ')', stop without consuming it.
        if (Tok.is(tok::r_paren))
          break;
  
        Diag(Tok.getLocation(), diag::err_ms_property_expected_comma_or_rparen);
        break;
      }
  
      // Only add the property attribute if it was well-formed.
      if (!HasInvalidAccessor)
        Attrs.addNewPropertyAttr(AttrName, AttrNameLoc, nullptr, SourceLocation(),
                                 AccessorNames[AK_Get], AccessorNames[AK_Put],
                                 ParsedAttr::AS_Declspec);
      T.skipToEnd();
      return !HasInvalidAccessor;
    }
  
    unsigned NumArgs =
        ParseAttributeArgsCommon(AttrName, AttrNameLoc, Attrs, nullptr, nullptr,
                                 SourceLocation(), ParsedAttr::AS_Declspec);
  
    // If this attribute's args were parsed, and it was expected to have
    // arguments but none were provided, emit a diagnostic.
    if (!Attrs.empty() && Attrs.begin()->getMaxArgs() && !NumArgs) {
      Diag(OpenParenLoc, diag::err_attribute_requires_arguments) << AttrName;
      return false;
    }
    return true;
  }
  
  /// [MS] decl-specifier:
  ///             __declspec ( extended-decl-modifier-seq )
  ///
  /// [MS] extended-decl-modifier-seq:
  ///             extended-decl-modifier[opt]
  ///             extended-decl-modifier extended-decl-modifier-seq
  void Parser::ParseMicrosoftDeclSpecs(ParsedAttributes &Attrs,
                                       SourceLocation *End) {
    assert(getLangOpts().DeclSpecKeyword && "__declspec keyword is not enabled");
    assert(Tok.is(tok::kw___declspec) && "Not a declspec!");
  
    while (Tok.is(tok::kw___declspec)) {
      ConsumeToken();
      BalancedDelimiterTracker T(*this, tok::l_paren);
      if (T.expectAndConsume(diag::err_expected_lparen_after, "__declspec",
                             tok::r_paren))
        return;
  
      // An empty declspec is perfectly legal and should not warn.  Additionally,
      // you can specify multiple attributes per declspec.
      while (Tok.isNot(tok::r_paren)) {
        // Attribute not present.
        if (TryConsumeToken(tok::comma))
          continue;
  
        // We expect either a well-known identifier or a generic string.  Anything
        // else is a malformed declspec.
        bool IsString = Tok.getKind() == tok::string_literal;
        if (!IsString && Tok.getKind() != tok::identifier &&
            Tok.getKind() != tok::kw_restrict) {
          Diag(Tok, diag::err_ms_declspec_type);
          T.skipToEnd();
          return;
        }
  
        IdentifierInfo *AttrName;
        SourceLocation AttrNameLoc;
        if (IsString) {
          SmallString<8> StrBuffer;
          bool Invalid = false;
          StringRef Str = PP.getSpelling(Tok, StrBuffer, &Invalid);
          if (Invalid) {
            T.skipToEnd();
            return;
          }
          AttrName = PP.getIdentifierInfo(Str);
          AttrNameLoc = ConsumeStringToken();
        } else {
          AttrName = Tok.getIdentifierInfo();
          AttrNameLoc = ConsumeToken();
        }
  
        bool AttrHandled = false;
  
        // Parse attribute arguments.
        if (Tok.is(tok::l_paren))
          AttrHandled = ParseMicrosoftDeclSpecArgs(AttrName, AttrNameLoc, Attrs);
        else if (AttrName->getName() == "property")
          // The property attribute must have an argument list.
          Diag(Tok.getLocation(), diag::err_expected_lparen_after)
              << AttrName->getName();
  
        if (!AttrHandled)
          Attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                       ParsedAttr::AS_Declspec);
      }
      T.consumeClose();
      if (End)
        *End = T.getCloseLocation();
    }
  }
  
  void Parser::ParseMicrosoftTypeAttributes(ParsedAttributes &attrs) {
    // Treat these like attributes
    while (true) {
      switch (Tok.getKind()) {
      case tok::kw___fastcall:
      case tok::kw___stdcall:
      case tok::kw___thiscall:
      case tok::kw___regcall:
      case tok::kw___cdecl:
      case tok::kw___vectorcall:
      case tok::kw___ptr64:
      case tok::kw___w64:
      case tok::kw___ptr32:
      case tok::kw___sptr:
      case tok::kw___uptr: {
        IdentifierInfo *AttrName = Tok.getIdentifierInfo();
        SourceLocation AttrNameLoc = ConsumeToken();
        attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                     ParsedAttr::AS_Keyword);
        break;
      }
      default:
        return;
      }
    }
  }
  
  void Parser::DiagnoseAndSkipExtendedMicrosoftTypeAttributes() {
    SourceLocation StartLoc = Tok.getLocation();
    SourceLocation EndLoc = SkipExtendedMicrosoftTypeAttributes();
  
    if (EndLoc.isValid()) {
      SourceRange Range(StartLoc, EndLoc);
      Diag(StartLoc, diag::warn_microsoft_qualifiers_ignored) << Range;
    }
  }
  
  SourceLocation Parser::SkipExtendedMicrosoftTypeAttributes() {
    SourceLocation EndLoc;
  
    while (true) {
      switch (Tok.getKind()) {
      case tok::kw_const:
      case tok::kw_volatile:
      case tok::kw___fastcall:
      case tok::kw___stdcall:
      case tok::kw___thiscall:
      case tok::kw___cdecl:
      case tok::kw___vectorcall:
      case tok::kw___ptr32:
      case tok::kw___ptr64:
      case tok::kw___w64:
      case tok::kw___unaligned:
      case tok::kw___sptr:
      case tok::kw___uptr:
        EndLoc = ConsumeToken();
        break;
      default:
        return EndLoc;
      }
    }
  }
  
  void Parser::ParseBorlandTypeAttributes(ParsedAttributes &attrs) {
    // Treat these like attributes
    while (Tok.is(tok::kw___pascal)) {
      IdentifierInfo *AttrName = Tok.getIdentifierInfo();
      SourceLocation AttrNameLoc = ConsumeToken();
      attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                   ParsedAttr::AS_Keyword);
    }
  }
  
  void Parser::ParseOpenCLKernelAttributes(ParsedAttributes &attrs) {
    // Treat these like attributes
    while (Tok.is(tok::kw___kernel)) {
      IdentifierInfo *AttrName = Tok.getIdentifierInfo();
      SourceLocation AttrNameLoc = ConsumeToken();
      attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                   ParsedAttr::AS_Keyword);
    }
  }
  
  void Parser::ParseOpenCLQualifiers(ParsedAttributes &Attrs) {
    IdentifierInfo *AttrName = Tok.getIdentifierInfo();
    SourceLocation AttrNameLoc = Tok.getLocation();
    Attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                 ParsedAttr::AS_Keyword);
  }
  
  void Parser::ParseNullabilityTypeSpecifiers(ParsedAttributes &attrs) {
    // Treat these like attributes, even though they're type specifiers.
    while (true) {
      switch (Tok.getKind()) {
      case tok::kw__Nonnull:
      case tok::kw__Nullable:
      case tok::kw__Null_unspecified: {
        IdentifierInfo *AttrName = Tok.getIdentifierInfo();
        SourceLocation AttrNameLoc = ConsumeToken();
        if (!getLangOpts().ObjC)
          Diag(AttrNameLoc, diag::ext_nullability)
            << AttrName;
        attrs.addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc, nullptr, 0,
                     ParsedAttr::AS_Keyword);
        break;
      }
      default:
        return;
      }
    }
  }
  
  static bool VersionNumberSeparator(const char Separator) {
    return (Separator == '.' || Separator == '_');
  }
  
  /// Parse a version number.
  ///
  /// version:
  ///   simple-integer
  ///   simple-integer '.' simple-integer
  ///   simple-integer '_' simple-integer
  ///   simple-integer '.' simple-integer '.' simple-integer
  ///   simple-integer '_' simple-integer '_' simple-integer
  VersionTuple Parser::ParseVersionTuple(SourceRange &Range) {
    Range = SourceRange(Tok.getLocation(), Tok.getEndLoc());
  
    if (!Tok.is(tok::numeric_constant)) {
      Diag(Tok, diag::err_expected_version);
      SkipUntil(tok::comma, tok::r_paren,
                StopAtSemi | StopBeforeMatch | StopAtCodeCompletion);
      return VersionTuple();
    }
  
    // Parse the major (and possibly minor and subminor) versions, which
    // are stored in the numeric constant. We utilize a quirk of the
    // lexer, which is that it handles something like 1.2.3 as a single
    // numeric constant, rather than two separate tokens.
    SmallString<512> Buffer;
    Buffer.resize(Tok.getLength()+1);
    const char *ThisTokBegin = &Buffer[0];
  
    // Get the spelling of the token, which eliminates trigraphs, etc.
    bool Invalid = false;
    unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid);
    if (Invalid)
      return VersionTuple();
  
    // Parse the major version.
    unsigned AfterMajor = 0;
    unsigned Major = 0;
    while (AfterMajor < ActualLength && isDigit(ThisTokBegin[AfterMajor])) {
      Major = Major * 10 + ThisTokBegin[AfterMajor] - '0';
      ++AfterMajor;
    }
  
    if (AfterMajor == 0) {
      Diag(Tok, diag::err_expected_version);
      SkipUntil(tok::comma, tok::r_paren,
                StopAtSemi | StopBeforeMatch | StopAtCodeCompletion);
      return VersionTuple();
    }
  
    if (AfterMajor == ActualLength) {
      ConsumeToken();
  
      // We only had a single version component.
      if (Major == 0) {
        Diag(Tok, diag::err_zero_version);
        return VersionTuple();
      }
  
      return VersionTuple(Major);
    }
  
    const char AfterMajorSeparator = ThisTokBegin[AfterMajor];
    if (!VersionNumberSeparator(AfterMajorSeparator)
        || (AfterMajor + 1 == ActualLength)) {
      Diag(Tok, diag::err_expected_version);
      SkipUntil(tok::comma, tok::r_paren,
                StopAtSemi | StopBeforeMatch | StopAtCodeCompletion);
      return VersionTuple();
    }
  
    // Parse the minor version.
    unsigned AfterMinor = AfterMajor + 1;
    unsigned Minor = 0;
    while (AfterMinor < ActualLength && isDigit(ThisTokBegin[AfterMinor])) {
      Minor = Minor * 10 + ThisTokBegin[AfterMinor] - '0';
      ++AfterMinor;
    }
  
    if (AfterMinor == ActualLength) {
      ConsumeToken();
  
      // We had major.minor.
      if (Major == 0 && Minor == 0) {
        Diag(Tok, diag::err_zero_version);
        return VersionTuple();
      }
  
      return VersionTuple(Major, Minor);
    }
  
    const char AfterMinorSeparator = ThisTokBegin[AfterMinor];
    // If what follows is not a '.' or '_', we have a problem.
    if (!VersionNumberSeparator(AfterMinorSeparator)) {
      Diag(Tok, diag::err_expected_version);
      SkipUntil(tok::comma, tok::r_paren,
                StopAtSemi | StopBeforeMatch | StopAtCodeCompletion);
      return VersionTuple();
    }
  
    // Warn if separators, be it '.' or '_', do not match.
    if (AfterMajorSeparator != AfterMinorSeparator)
      Diag(Tok, diag::warn_expected_consistent_version_separator);
  
    // Parse the subminor version.
    unsigned AfterSubminor = AfterMinor + 1;
    unsigned Subminor = 0;
    while (AfterSubminor < ActualLength && isDigit(ThisTokBegin[AfterSubminor])) {
      Subminor = Subminor * 10 + ThisTokBegin[AfterSubminor] - '0';
      ++AfterSubminor;
    }
  
    if (AfterSubminor != ActualLength) {
      Diag(Tok, diag::err_expected_version);
      SkipUntil(tok::comma, tok::r_paren,
                StopAtSemi | StopBeforeMatch | StopAtCodeCompletion);
      return VersionTuple();
    }
    ConsumeToken();
    return VersionTuple(Major, Minor, Subminor);
  }
  
  /// Parse the contents of the "availability" attribute.
  ///
  /// availability-attribute:
  ///   'availability' '(' platform ',' opt-strict version-arg-list,
  ///                      opt-replacement, opt-message')'
  ///
  /// platform:
  ///   identifier
  ///
  /// opt-strict:
  ///   'strict' ','
  ///
  /// version-arg-list:
  ///   version-arg
  ///   version-arg ',' version-arg-list
  ///
  /// version-arg:
  ///   'introduced' '=' version
  ///   'deprecated' '=' version
  ///   'obsoleted' = version
  ///   'unavailable'
  /// opt-replacement:
  ///   'replacement' '=' <string>
  /// opt-message:
  ///   'message' '=' <string>
  void Parser::ParseAvailabilityAttribute(IdentifierInfo &Availability,
                                          SourceLocation AvailabilityLoc,
                                          ParsedAttributes &attrs,
                                          SourceLocation *endLoc,
                                          IdentifierInfo *ScopeName,
                                          SourceLocation ScopeLoc,
                                          ParsedAttr::Syntax Syntax) {
    enum { Introduced, Deprecated, Obsoleted, Unknown };
    AvailabilityChange Changes[Unknown];
    ExprResult MessageExpr, ReplacementExpr;
  
    // Opening '('.
    BalancedDelimiterTracker T(*this, tok::l_paren);
    if (T.consumeOpen()) {
      Diag(Tok, diag::err_expected) << tok::l_paren;
      return;
    }
  
    // Parse the platform name.
    if (Tok.isNot(tok::identifier)) {
      Diag(Tok, diag::err_availability_expected_platform);
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
    IdentifierLoc *Platform = ParseIdentifierLoc();
    if (const IdentifierInfo *const Ident = Platform->Ident) {
      // Canonicalize platform name from "macosx" to "macos".
      if (Ident->getName() == "macosx")
        Platform->Ident = PP.getIdentifierInfo("macos");
      // Canonicalize platform name from "macosx_app_extension" to
      // "macos_app_extension".
      else if (Ident->getName() == "macosx_app_extension")
        Platform->Ident = PP.getIdentifierInfo("macos_app_extension");
      else
        Platform->Ident = PP.getIdentifierInfo(
            AvailabilityAttr::canonicalizePlatformName(Ident->getName()));
    }
  
    // Parse the ',' following the platform name.
    if (ExpectAndConsume(tok::comma)) {
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
  
    // If we haven't grabbed the pointers for the identifiers
    // "introduced", "deprecated", and "obsoleted", do so now.
    if (!Ident_introduced) {
      Ident_introduced = PP.getIdentifierInfo("introduced");
      Ident_deprecated = PP.getIdentifierInfo("deprecated");
      Ident_obsoleted = PP.getIdentifierInfo("obsoleted");
      Ident_unavailable = PP.getIdentifierInfo("unavailable");
      Ident_message = PP.getIdentifierInfo("message");
      Ident_strict = PP.getIdentifierInfo("strict");
      Ident_replacement = PP.getIdentifierInfo("replacement");
    }
  
    // Parse the optional "strict", the optional "replacement" and the set of
    // introductions/deprecations/removals.
    SourceLocation UnavailableLoc, StrictLoc;
    do {
      if (Tok.isNot(tok::identifier)) {
        Diag(Tok, diag::err_availability_expected_change);
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
      IdentifierInfo *Keyword = Tok.getIdentifierInfo();
      SourceLocation KeywordLoc = ConsumeToken();
  
      if (Keyword == Ident_strict) {
        if (StrictLoc.isValid()) {
          Diag(KeywordLoc, diag::err_availability_redundant)
            << Keyword << SourceRange(StrictLoc);
        }
        StrictLoc = KeywordLoc;
        continue;
      }
  
      if (Keyword == Ident_unavailable) {
        if (UnavailableLoc.isValid()) {
          Diag(KeywordLoc, diag::err_availability_redundant)
            << Keyword << SourceRange(UnavailableLoc);
        }
        UnavailableLoc = KeywordLoc;
        continue;
      }
  
      if (Keyword == Ident_deprecated && Platform->Ident &&
          Platform->Ident->isStr("swift")) {
        // For swift, we deprecate for all versions.
        if (Changes[Deprecated].KeywordLoc.isValid()) {
          Diag(KeywordLoc, diag::err_availability_redundant)
            << Keyword
            << SourceRange(Changes[Deprecated].KeywordLoc);
        }
  
        Changes[Deprecated].KeywordLoc = KeywordLoc;
        // Use a fake version here.
        Changes[Deprecated].Version = VersionTuple(1);
        continue;
      }
  
      if (Tok.isNot(tok::equal)) {
        Diag(Tok, diag::err_expected_after) << Keyword << tok::equal;
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
      ConsumeToken();
      if (Keyword == Ident_message || Keyword == Ident_replacement) {
        if (Tok.isNot(tok::string_literal)) {
          Diag(Tok, diag::err_expected_string_literal)
            << /*Source='availability attribute'*/2;
          SkipUntil(tok::r_paren, StopAtSemi);
          return;
        }
        if (Keyword == Ident_message)
          MessageExpr = ParseStringLiteralExpression();
        else
          ReplacementExpr = ParseStringLiteralExpression();
        // Also reject wide string literals.
        if (StringLiteral *MessageStringLiteral =
                cast_or_null<StringLiteral>(MessageExpr.get())) {
          if (MessageStringLiteral->getCharByteWidth() != 1) {
            Diag(MessageStringLiteral->getSourceRange().getBegin(),
                 diag::err_expected_string_literal)
              << /*Source='availability attribute'*/ 2;
            SkipUntil(tok::r_paren, StopAtSemi);
            return;
          }
        }
        if (Keyword == Ident_message)
          break;
        else
          continue;
      }
  
      // Special handling of 'NA' only when applied to introduced or
      // deprecated.
      if ((Keyword == Ident_introduced || Keyword == Ident_deprecated) &&
          Tok.is(tok::identifier)) {
        IdentifierInfo *NA = Tok.getIdentifierInfo();
        if (NA->getName() == "NA") {
          ConsumeToken();
          if (Keyword == Ident_introduced)
            UnavailableLoc = KeywordLoc;
          continue;
        }
      }
  
      SourceRange VersionRange;
      VersionTuple Version = ParseVersionTuple(VersionRange);
  
      if (Version.empty()) {
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
  
      unsigned Index;
      if (Keyword == Ident_introduced)
        Index = Introduced;
      else if (Keyword == Ident_deprecated)
        Index = Deprecated;
      else if (Keyword == Ident_obsoleted)
        Index = Obsoleted;
      else
        Index = Unknown;
  
      if (Index < Unknown) {
        if (!Changes[Index].KeywordLoc.isInvalid()) {
          Diag(KeywordLoc, diag::err_availability_redundant)
            << Keyword
            << SourceRange(Changes[Index].KeywordLoc,
                           Changes[Index].VersionRange.getEnd());
        }
  
        Changes[Index].KeywordLoc = KeywordLoc;
        Changes[Index].Version = Version;
        Changes[Index].VersionRange = VersionRange;
      } else {
        Diag(KeywordLoc, diag::err_availability_unknown_change)
          << Keyword << VersionRange;
      }
  
    } while (TryConsumeToken(tok::comma));
  
    // Closing ')'.
    if (T.consumeClose())
      return;
  
    if (endLoc)
      *endLoc = T.getCloseLocation();
  
    // The 'unavailable' availability cannot be combined with any other
    // availability changes. Make sure that hasn't happened.
    if (UnavailableLoc.isValid()) {
      bool Complained = false;
      for (unsigned Index = Introduced; Index != Unknown; ++Index) {
        if (Changes[Index].KeywordLoc.isValid()) {
          if (!Complained) {
            Diag(UnavailableLoc, diag::warn_availability_and_unavailable)
              << SourceRange(Changes[Index].KeywordLoc,
                             Changes[Index].VersionRange.getEnd());
            Complained = true;
          }
  
          // Clear out the availability.
          Changes[Index] = AvailabilityChange();
        }
      }
    }
  
    // Record this attribute
    attrs.addNew(&Availability,
                 SourceRange(AvailabilityLoc, T.getCloseLocation()),
                 ScopeName, ScopeLoc,
                 Platform,
                 Changes[Introduced],
                 Changes[Deprecated],
                 Changes[Obsoleted],
                 UnavailableLoc, MessageExpr.get(),
                 Syntax, StrictLoc, ReplacementExpr.get());
  }
  
  /// Parse the contents of the "external_source_symbol" attribute.
  ///
  /// external-source-symbol-attribute:
  ///   'external_source_symbol' '(' keyword-arg-list ')'
  ///
  /// keyword-arg-list:
  ///   keyword-arg
  ///   keyword-arg ',' keyword-arg-list
  ///
  /// keyword-arg:
  ///   'language' '=' <string>
  ///   'defined_in' '=' <string>
  ///   'generated_declaration'
  void Parser::ParseExternalSourceSymbolAttribute(
      IdentifierInfo &ExternalSourceSymbol, SourceLocation Loc,
      ParsedAttributes &Attrs, SourceLocation *EndLoc, IdentifierInfo *ScopeName,
      SourceLocation ScopeLoc, ParsedAttr::Syntax Syntax) {
    // Opening '('.
    BalancedDelimiterTracker T(*this, tok::l_paren);
    if (T.expectAndConsume())
      return;
  
    // Initialize the pointers for the keyword identifiers when required.
    if (!Ident_language) {
      Ident_language = PP.getIdentifierInfo("language");
      Ident_defined_in = PP.getIdentifierInfo("defined_in");
      Ident_generated_declaration = PP.getIdentifierInfo("generated_declaration");
    }
  
    ExprResult Language;
    bool HasLanguage = false;
    ExprResult DefinedInExpr;
    bool HasDefinedIn = false;
    IdentifierLoc *GeneratedDeclaration = nullptr;
  
    // Parse the language/defined_in/generated_declaration keywords
    do {
      if (Tok.isNot(tok::identifier)) {
        Diag(Tok, diag::err_external_source_symbol_expected_keyword);
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
  
      SourceLocation KeywordLoc = Tok.getLocation();
      IdentifierInfo *Keyword = Tok.getIdentifierInfo();
      if (Keyword == Ident_generated_declaration) {
        if (GeneratedDeclaration) {
          Diag(Tok, diag::err_external_source_symbol_duplicate_clause) << Keyword;
          SkipUntil(tok::r_paren, StopAtSemi);
          return;
        }
        GeneratedDeclaration = ParseIdentifierLoc();
        continue;
      }
  
      if (Keyword != Ident_language && Keyword != Ident_defined_in) {
        Diag(Tok, diag::err_external_source_symbol_expected_keyword);
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
  
      ConsumeToken();
      if (ExpectAndConsume(tok::equal, diag::err_expected_after,
                           Keyword->getName())) {
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
  
      bool HadLanguage = HasLanguage, HadDefinedIn = HasDefinedIn;
      if (Keyword == Ident_language)
        HasLanguage = true;
      else
        HasDefinedIn = true;
  
      if (Tok.isNot(tok::string_literal)) {
        Diag(Tok, diag::err_expected_string_literal)
            << /*Source='external_source_symbol attribute'*/ 3
            << /*language | source container*/ (Keyword != Ident_language);
        SkipUntil(tok::comma, tok::r_paren, StopAtSemi | StopBeforeMatch);
        continue;
      }
      if (Keyword == Ident_language) {
        if (HadLanguage) {
          Diag(KeywordLoc, diag::err_external_source_symbol_duplicate_clause)
              << Keyword;
          ParseStringLiteralExpression();
          continue;
        }
        Language = ParseStringLiteralExpression();
      } else {
        assert(Keyword == Ident_defined_in && "Invalid clause keyword!");
        if (HadDefinedIn) {
          Diag(KeywordLoc, diag::err_external_source_symbol_duplicate_clause)
              << Keyword;
          ParseStringLiteralExpression();
          continue;
        }
        DefinedInExpr = ParseStringLiteralExpression();
      }
    } while (TryConsumeToken(tok::comma));
  
    // Closing ')'.
    if (T.consumeClose())
      return;
    if (EndLoc)
      *EndLoc = T.getCloseLocation();
  
    ArgsUnion Args[] = {Language.get(), DefinedInExpr.get(),
                        GeneratedDeclaration};
    Attrs.addNew(&ExternalSourceSymbol, SourceRange(Loc, T.getCloseLocation()),
                 ScopeName, ScopeLoc, Args, llvm::array_lengthof(Args), Syntax);
  }
  
  /// Parse the contents of the "objc_bridge_related" attribute.
  /// objc_bridge_related '(' related_class ',' opt-class_method ',' opt-instance_method ')'
  /// related_class:
  ///     Identifier
  ///
  /// opt-class_method:
  ///     Identifier: | <empty>
  ///
  /// opt-instance_method:
  ///     Identifier | <empty>
  ///
  void Parser::ParseObjCBridgeRelatedAttribute(IdentifierInfo &ObjCBridgeRelated,
                                  SourceLocation ObjCBridgeRelatedLoc,
                                  ParsedAttributes &attrs,
                                  SourceLocation *endLoc,
                                  IdentifierInfo *ScopeName,
                                  SourceLocation ScopeLoc,
                                  ParsedAttr::Syntax Syntax) {
    // Opening '('.
    BalancedDelimiterTracker T(*this, tok::l_paren);
    if (T.consumeOpen()) {
      Diag(Tok, diag::err_expected) << tok::l_paren;
      return;
    }
  
    // Parse the related class name.
    if (Tok.isNot(tok::identifier)) {
      Diag(Tok, diag::err_objcbridge_related_expected_related_class);
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
    IdentifierLoc *RelatedClass = ParseIdentifierLoc();
    if (ExpectAndConsume(tok::comma)) {
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
  
    // Parse class method name.  It's non-optional in the sense that a trailing
    // comma is required, but it can be the empty string, and then we record a
    // nullptr.
    IdentifierLoc *ClassMethod = nullptr;
    if (Tok.is(tok::identifier)) {
      ClassMethod = ParseIdentifierLoc();
      if (!TryConsumeToken(tok::colon)) {
        Diag(Tok, diag::err_objcbridge_related_selector_name);
        SkipUntil(tok::r_paren, StopAtSemi);
        return;
      }
    }
    if (!TryConsumeToken(tok::comma)) {
      if (Tok.is(tok::colon))
        Diag(Tok, diag::err_objcbridge_related_selector_name);
      else
        Diag(Tok, diag::err_expected) << tok::comma;
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
  
    // Parse instance method name.  Also non-optional but empty string is
    // permitted.
    IdentifierLoc *InstanceMethod = nullptr;
    if (Tok.is(tok::identifier))
      InstanceMethod = ParseIdentifierLoc();
    else if (Tok.isNot(tok::r_paren)) {
      Diag(Tok, diag::err_expected) << tok::r_paren;
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
  
    // Closing ')'.
    if (T.consumeClose())
      return;
  
    if (endLoc)
      *endLoc = T.getCloseLocation();
  
    // Record this attribute
    attrs.addNew(&ObjCBridgeRelated,
                 SourceRange(ObjCBridgeRelatedLoc, T.getCloseLocation()),
                 ScopeName, ScopeLoc,
                 RelatedClass,
                 ClassMethod,
                 InstanceMethod,
                 Syntax);
  }
  
  // Late Parsed Attributes:
  // See other examples of late parsing in lib/Parse/ParseCXXInlineMethods
  
  void Parser::LateParsedDeclaration::ParseLexedAttributes() {}
  
  void Parser::LateParsedClass::ParseLexedAttributes() {
    Self->ParseLexedAttributes(*Class);
  }
  
  void Parser::LateParsedAttribute::ParseLexedAttributes() {
    Self->ParseLexedAttribute(*this, true, false);
  }
  
  /// Wrapper class which calls ParseLexedAttribute, after setting up the
  /// scope appropriately.
  void Parser::ParseLexedAttributes(ParsingClass &Class) {
    // Deal with templates
    // FIXME: Test cases to make sure this does the right thing for templates.
    bool HasTemplateScope = !Class.TopLevelClass && Class.TemplateScope;
    ParseScope ClassTemplateScope(this, Scope::TemplateParamScope,
                                  HasTemplateScope);
    if (HasTemplateScope)
      Actions.ActOnReenterTemplateScope(getCurScope(), Class.TagOrTemplate);
  
    // Set or update the scope flags.
    bool AlreadyHasClassScope = Class.TopLevelClass;
    unsigned ScopeFlags = Scope::ClassScope|Scope::DeclScope;
    ParseScope ClassScope(this, ScopeFlags, !AlreadyHasClassScope);
    ParseScopeFlags ClassScopeFlags(this, ScopeFlags, AlreadyHasClassScope);
  
    // Enter the scope of nested classes
    if (!AlreadyHasClassScope)
      Actions.ActOnStartDelayedMemberDeclarations(getCurScope(),
                                                  Class.TagOrTemplate);
    if (!Class.LateParsedDeclarations.empty()) {
      for (unsigned i = 0, ni = Class.LateParsedDeclarations.size(); i < ni; ++i){
        Class.LateParsedDeclarations[i]->ParseLexedAttributes();
      }
    }
  
    if (!AlreadyHasClassScope)
      Actions.ActOnFinishDelayedMemberDeclarations(getCurScope(),
                                                   Class.TagOrTemplate);
  }
  
  /// Parse all attributes in LAs, and attach them to Decl D.
  void Parser::ParseLexedAttributeList(LateParsedAttrList &LAs, Decl *D,
                                       bool EnterScope, bool OnDefinition) {
    assert(LAs.parseSoon() &&
           "Attribute list should be marked for immediate parsing.");
    for (unsigned i = 0, ni = LAs.size(); i < ni; ++i) {
      if (D)
        LAs[i]->addDecl(D);
      ParseLexedAttribute(*LAs[i], EnterScope, OnDefinition);
      delete LAs[i];
    }
    LAs.clear();
  }
  
  /// Finish parsing an attribute for which parsing was delayed.
  /// This will be called at the end of parsing a class declaration
  /// for each LateParsedAttribute. We consume the saved tokens and
  /// create an attribute with the arguments filled in. We add this
  /// to the Attribute list for the decl.
  void Parser::ParseLexedAttribute(LateParsedAttribute &LA,
                                   bool EnterScope, bool OnDefinition) {
    // Create a fake EOF so that attribute parsing won't go off the end of the
    // attribute.
    Token AttrEnd;
    AttrEnd.startToken();
    AttrEnd.setKind(tok::eof);
    AttrEnd.setLocation(Tok.getLocation());
    AttrEnd.setEofData(LA.Toks.data());
    LA.Toks.push_back(AttrEnd);
  
    // Append the current token at the end of the new token stream so that it
    // doesn't get lost.
    LA.Toks.push_back(Tok);
    PP.EnterTokenStream(LA.Toks, true, /*IsReinject=*/true);
    // Consume the previously pushed token.
    ConsumeAnyToken(/*ConsumeCodeCompletionTok=*/true);
  
    ParsedAttributes Attrs(AttrFactory);
    SourceLocation endLoc;
  
    if (LA.Decls.size() > 0) {
      Decl *D = LA.Decls[0];
      NamedDecl *ND  = dyn_cast<NamedDecl>(D);
      RecordDecl *RD = dyn_cast_or_null<RecordDecl>(D->getDeclContext());
  
      // Allow 'this' within late-parsed attributes.
      Sema::CXXThisScopeRAII ThisScope(Actions, RD, Qualifiers(),
                                       ND && ND->isCXXInstanceMember());
  
      if (LA.Decls.size() == 1) {
        // If the Decl is templatized, add template parameters to scope.
        bool HasTemplateScope = EnterScope && D->isTemplateDecl();
        ParseScope TempScope(this, Scope::TemplateParamScope, HasTemplateScope);
        if (HasTemplateScope)
          Actions.ActOnReenterTemplateScope(Actions.CurScope, D);
  
        // If the Decl is on a function, add function parameters to the scope.
        bool HasFunScope = EnterScope && D->isFunctionOrFunctionTemplate();
        ParseScope FnScope(
            this, Scope::FnScope | Scope::DeclScope | Scope::CompoundStmtScope,
            HasFunScope);
        if (HasFunScope)
          Actions.ActOnReenterFunctionContext(Actions.CurScope, D);
  
        ParseGNUAttributeArgs(&LA.AttrName, LA.AttrNameLoc, Attrs, &endLoc,
                              nullptr, SourceLocation(), ParsedAttr::AS_GNU,
                              nullptr);
  
        if (HasFunScope) {
          Actions.ActOnExitFunctionContext();
          FnScope.Exit();  // Pop scope, and remove Decls from IdResolver
        }
        if (HasTemplateScope) {
          TempScope.Exit();
        }
      } else {
        // If there are multiple decls, then the decl cannot be within the
        // function scope.
        ParseGNUAttributeArgs(&LA.AttrName, LA.AttrNameLoc, Attrs, &endLoc,
                              nullptr, SourceLocation(), ParsedAttr::AS_GNU,
                              nullptr);
      }
    } else {
      Diag(Tok, diag::warn_attribute_no_decl) << LA.AttrName.getName();
    }
  
    if (OnDefinition && !Attrs.empty() && !Attrs.begin()->isCXX11Attribute() &&
        Attrs.begin()->isKnownToGCC())
      Diag(Tok, diag::warn_attribute_on_function_definition)
        << &LA.AttrName;
  
    for (unsigned i = 0, ni = LA.Decls.size(); i < ni; ++i)
      Actions.ActOnFinishDelayedAttribute(getCurScope(), LA.Decls[i], Attrs);
  
    // Due to a parsing error, we either went over the cached tokens or
    // there are still cached tokens left, so we skip the leftover tokens.
    while (Tok.isNot(tok::eof))
      ConsumeAnyToken();
  
    if (Tok.is(tok::eof) && Tok.getEofData() == AttrEnd.getEofData())
      ConsumeAnyToken();
  }
  
  void Parser::ParseTypeTagForDatatypeAttribute(IdentifierInfo &AttrName,
                                                SourceLocation AttrNameLoc,
                                                ParsedAttributes &Attrs,
                                                SourceLocation *EndLoc,
                                                IdentifierInfo *ScopeName,
                                                SourceLocation ScopeLoc,
                                                ParsedAttr::Syntax Syntax) {
    assert(Tok.is(tok::l_paren) && "Attribute arg list not starting with '('");
  
    BalancedDelimiterTracker T(*this, tok::l_paren);
    T.consumeOpen();
  
    if (Tok.isNot(tok::identifier)) {
      Diag(Tok, diag::err_expected) << tok::identifier;
      T.skipToEnd();
      return;
    }
    IdentifierLoc *ArgumentKind = ParseIdentifierLoc();
  
    if (ExpectAndConsume(tok::comma)) {
      T.skipToEnd();
      return;
    }
  
    SourceRange MatchingCTypeRange;
    TypeResult MatchingCType = ParseTypeName(&MatchingCTypeRange);
    if (MatchingCType.isInvalid()) {
      T.skipToEnd();
      return;
    }
  
    bool LayoutCompatible = false;
    bool MustBeNull = false;
    while (TryConsumeToken(tok::comma)) {
      if (Tok.isNot(tok::identifier)) {
        Diag(Tok, diag::err_expected) << tok::identifier;
        T.skipToEnd();
        return;
      }
      IdentifierInfo *Flag = Tok.getIdentifierInfo();
      if (Flag->isStr("layout_compatible"))
        LayoutCompatible = true;
      else if (Flag->isStr("must_be_null"))
        MustBeNull = true;
      else {
        Diag(Tok, diag::err_type_safety_unknown_flag) << Flag;
        T.skipToEnd();
        return;
      }
      ConsumeToken(); // consume flag
    }
  
    if (!T.consumeClose()) {
      Attrs.addNewTypeTagForDatatype(&AttrName, AttrNameLoc, ScopeName, ScopeLoc,
                                     ArgumentKind, MatchingCType.get(),
                                     LayoutCompatible, MustBeNull, Syntax);
    }
  
    if (EndLoc)
      *EndLoc = T.getCloseLocation();
  }
  
  /// DiagnoseProhibitedCXX11Attribute - We have found the opening square brackets
  /// of a C++11 attribute-specifier in a location where an attribute is not
  /// permitted. By C++11 [dcl.attr.grammar]p6, this is ill-formed. Diagnose this
  /// situation.
  ///
  /// \return \c true if we skipped an attribute-like chunk of tokens, \c false if
  /// this doesn't appear to actually be an attribute-specifier, and the caller
  /// should try to parse it.
  bool Parser::DiagnoseProhibitedCXX11Attribute() {
    assert(Tok.is(tok::l_square) && NextToken().is(tok::l_square));
  
    switch (isCXX11AttributeSpecifier(/*Disambiguate*/true)) {
    case CAK_NotAttributeSpecifier:
      // No diagnostic: we're in Obj-C++11 and this is not actually an attribute.
      return false;
  
    case CAK_InvalidAttributeSpecifier:
      Diag(Tok.getLocation(), diag::err_l_square_l_square_not_attribute);
      return false;
  
    case CAK_AttributeSpecifier:
      // Parse and discard the attributes.
      SourceLocation BeginLoc = ConsumeBracket();
      ConsumeBracket();
      SkipUntil(tok::r_square);
      assert(Tok.is(tok::r_square) && "isCXX11AttributeSpecifier lied");
      SourceLocation EndLoc = ConsumeBracket();
      Diag(BeginLoc, diag::err_attributes_not_allowed)
        << SourceRange(BeginLoc, EndLoc);
      return true;
    }
    llvm_unreachable("All cases handled above.");
  }
  
  /// We have found the opening square brackets of a C++11
  /// attribute-specifier in a location where an attribute is not permitted, but
  /// we know where the attributes ought to be written. Parse them anyway, and
  /// provide a fixit moving them to the right place.
  void Parser::DiagnoseMisplacedCXX11Attribute(ParsedAttributesWithRange &Attrs,
                                               SourceLocation CorrectLocation) {
    assert((Tok.is(tok::l_square) && NextToken().is(tok::l_square)) ||
           Tok.is(tok::kw_alignas));
  
    // Consume the attributes.
    SourceLocation Loc = Tok.getLocation();
    ParseCXX11Attributes(Attrs);
    CharSourceRange AttrRange(SourceRange(Loc, Attrs.Range.getEnd()), true);
    // FIXME: use err_attributes_misplaced
    Diag(Loc, diag::err_attributes_not_allowed)
      << FixItHint::CreateInsertionFromRange(CorrectLocation, AttrRange)
      << FixItHint::CreateRemoval(AttrRange);
  }
  
  void Parser::DiagnoseProhibitedAttributes(
      const SourceRange &Range, const SourceLocation CorrectLocation) {
    if (CorrectLocation.isValid()) {
      CharSourceRange AttrRange(Range, true);
      Diag(CorrectLocation, diag::err_attributes_misplaced)
          << FixItHint::CreateInsertionFromRange(CorrectLocation, AttrRange)
          << FixItHint::CreateRemoval(AttrRange);
    } else
      Diag(Range.getBegin(), diag::err_attributes_not_allowed) << Range;
  }
  
  void Parser::ProhibitCXX11Attributes(ParsedAttributesWithRange &Attrs,
                                       unsigned DiagID) {
    for (const ParsedAttr &AL : Attrs) {
      if (!AL.isCXX11Attribute() && !AL.isC2xAttribute())
        continue;
      if (AL.getKind() == ParsedAttr::UnknownAttribute)
        Diag(AL.getLoc(), diag::warn_unknown_attribute_ignored) << AL.getName();
      else {
        Diag(AL.getLoc(), DiagID) << AL.getName();
        AL.setInvalid();
      }
    }
  }
  
  // Usually, `__attribute__((attrib)) class Foo {} var` means that attribute
  // applies to var, not the type Foo.
  // As an exception to the rule, __declspec(align(...)) before the
  // class-key affects the type instead of the variable.
  // Also, Microsoft-style [attributes] seem to affect the type instead of the
  // variable.
  // This function moves attributes that should apply to the type off DS to Attrs.
  void Parser::stripTypeAttributesOffDeclSpec(ParsedAttributesWithRange &Attrs,
                                              DeclSpec &DS,
                                              Sema::TagUseKind TUK) {
    if (TUK == Sema::TUK_Reference)
      return;
  
    llvm::SmallVector<ParsedAttr *, 1> ToBeMoved;
  
    for (ParsedAttr &AL : DS.getAttributes()) {
      if ((AL.getKind() == ParsedAttr::AT_Aligned &&
           AL.isDeclspecAttribute()) ||
          AL.isMicrosoftAttribute())
        ToBeMoved.push_back(&AL);
    }
  
    for (ParsedAttr *AL : ToBeMoved) {
      DS.getAttributes().remove(AL);
      Attrs.addAtEnd(AL);
    }
  }
  
  /// ParseDeclaration - Parse a full 'declaration', which consists of
  /// declaration-specifiers, some number of declarators, and a semicolon.
  /// 'Context' should be a DeclaratorContext value.  This returns the
  /// location of the semicolon in DeclEnd.
  ///
  ///       declaration: [C99 6.7]
  ///         block-declaration ->
  ///           simple-declaration
  ///           others                   [FIXME]
  /// [C++]   template-declaration
  /// [C++]   namespace-definition
  /// [C++]   using-directive
  /// [C++]   using-declaration
  /// [C++11/C11] static_assert-declaration
  ///         others... [FIXME]
  ///
  Parser::DeclGroupPtrTy Parser::ParseDeclaration(DeclaratorContext Context,
                                                  SourceLocation &DeclEnd,
                                            ParsedAttributesWithRange &attrs) {
    ParenBraceBracketBalancer BalancerRAIIObj(*this);
    // Must temporarily exit the objective-c container scope for
    // parsing c none objective-c decls.
    ObjCDeclContextSwitch ObjCDC(*this);
  
    Decl *SingleDecl = nullptr;
    switch (Tok.getKind()) {
    case tok::kw_template:
    case tok::kw_export:
      ProhibitAttributes(attrs);
      SingleDecl = ParseDeclarationStartingWithTemplate(Context, DeclEnd, attrs);
      break;
    case tok::kw_inline:
      // Could be the start of an inline namespace. Allowed as an ext in C++03.
      if (getLangOpts().CPlusPlus && NextToken().is(tok::kw_namespace)) {
        ProhibitAttributes(attrs);
        SourceLocation InlineLoc = ConsumeToken();
        return ParseNamespace(Context, DeclEnd, InlineLoc);
      }
      return ParseSimpleDeclaration(Context, DeclEnd, attrs,
                                    true);
    case tok::kw_namespace:
      ProhibitAttributes(attrs);
      return ParseNamespace(Context, DeclEnd);
    case tok::kw_using:
      return ParseUsingDirectiveOrDeclaration(Context, ParsedTemplateInfo(),
                                              DeclEnd, attrs);
    case tok::kw_static_assert:
    case tok::kw__Static_assert:
      ProhibitAttributes(attrs);
      SingleDecl = ParseStaticAssertDeclaration(DeclEnd);
      break;
    default:
      return ParseSimpleDeclaration(Context, DeclEnd, attrs, true);
    }
  
    // This routine returns a DeclGroup, if the thing we parsed only contains a
    // single decl, convert it now.
    return Actions.ConvertDeclToDeclGroup(SingleDecl);
  }
  
  ///       simple-declaration: [C99 6.7: declaration] [C++ 7p1: dcl.dcl]
  ///         declaration-specifiers init-declarator-list[opt] ';'
  /// [C++11] attribute-specifier-seq decl-specifier-seq[opt]
  ///             init-declarator-list ';'
  ///[C90/C++]init-declarator-list ';'                             [TODO]
  /// [OMP]   threadprivate-directive
  /// [OMP]   allocate-directive                                   [TODO]
  ///
  ///       for-range-declaration: [C++11 6.5p1: stmt.ranged]
  ///         attribute-specifier-seq[opt] type-specifier-seq declarator
  ///
  /// If RequireSemi is false, this does not check for a ';' at the end of the
  /// declaration.  If it is true, it checks for and eats it.
  ///
  /// If FRI is non-null, we might be parsing a for-range-declaration instead
  /// of a simple-declaration. If we find that we are, we also parse the
  /// for-range-initializer, and place it here.
  Parser::DeclGroupPtrTy
  Parser::ParseSimpleDeclaration(DeclaratorContext Context,
                                 SourceLocation &DeclEnd,
                                 ParsedAttributesWithRange &Attrs,
                                 bool RequireSemi, ForRangeInit *FRI) {
    // Parse the common declaration-specifiers piece.
    ParsingDeclSpec DS(*this);
  
    DeclSpecContext DSContext = getDeclSpecContextFromDeclaratorContext(Context);
    ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS_none, DSContext);
  
    // If we had a free-standing type definition with a missing semicolon, we
    // may get this far before the problem becomes obvious.
    if (DS.hasTagDefinition() &&
        DiagnoseMissingSemiAfterTagDefinition(DS, AS_none, DSContext))
      return nullptr;
  
    // C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };"
    // declaration-specifiers init-declarator-list[opt] ';'
    if (Tok.is(tok::semi)) {
      ProhibitAttributes(Attrs);
      DeclEnd = Tok.getLocation();
      if (RequireSemi) ConsumeToken();
      RecordDecl *AnonRecord = nullptr;
      Decl *TheDecl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS_none,
                                                         DS, AnonRecord);
      DS.complete(TheDecl);
      if (AnonRecord) {
        Decl* decls[] = {AnonRecord, TheDecl};
        return Actions.BuildDeclaratorGroup(decls);
      }
      return Actions.ConvertDeclToDeclGroup(TheDecl);
    }
  
    DS.takeAttributesFrom(Attrs);
    return ParseDeclGroup(DS, Context, &DeclEnd, FRI);
  }
  
  /// Returns true if this might be the start of a declarator, or a common typo
  /// for a declarator.
  bool Parser::MightBeDeclarator(DeclaratorContext Context) {
    switch (Tok.getKind()) {
    case tok::annot_cxxscope:
    case tok::annot_template_id:
    case tok::caret:
    case tok::code_completion:
    case tok::coloncolon:
    case tok::ellipsis:
    case tok::kw___attribute:
    case tok::kw_operator:
    case tok::l_paren:
    case tok::star:
      return true;
  
    case tok::amp:
    case tok::ampamp:
      return getLangOpts().CPlusPlus;
  
    case tok::l_square: // Might be an attribute on an unnamed bit-field.
      return Context == DeclaratorContext::MemberContext &&
             getLangOpts().CPlusPlus11 && NextToken().is(tok::l_square);
  
    case tok::colon: // Might be a typo for '::' or an unnamed bit-field.
      return Context == DeclaratorContext::MemberContext ||
             getLangOpts().CPlusPlus;
  
    case tok::identifier:
      switch (NextToken().getKind()) {
      case tok::code_completion:
      case tok::coloncolon:
      case tok::comma:
      case tok::equal:
      case tok::equalequal: // Might be a typo for '='.
      case tok::kw_alignas:
      case tok::kw_asm:
      case tok::kw___attribute:
      case tok::l_brace:
      case tok::l_paren:
      case tok::l_square:
      case tok::less:
      case tok::r_brace:
      case tok::r_paren:
      case tok::r_square:
      case tok::semi:
        return true;
  
      case tok::colon:
        // At namespace scope, 'identifier:' is probably a typo for 'identifier::'
        // and in block scope it's probably a label. Inside a class definition,
        // this is a bit-field.
        return Context == DeclaratorContext::MemberContext ||
               (getLangOpts().CPlusPlus &&
                Context == DeclaratorContext::FileContext);
  
      case tok::identifier: // Possible virt-specifier.
        return getLangOpts().CPlusPlus11 && isCXX11VirtSpecifier(NextToken());
  
      default:
        return false;
      }
  
    default:
      return false;
    }
  }
  
  /// Skip until we reach something which seems like a sensible place to pick
  /// up parsing after a malformed declaration. This will sometimes stop sooner
  /// than SkipUntil(tok::r_brace) would, but will never stop later.
  void Parser::SkipMalformedDecl() {
    while (true) {
      switch (Tok.getKind()) {
      case tok::l_brace:
        // Skip until matching }, then stop. We've probably skipped over
        // a malformed class or function definition or similar.
        ConsumeBrace();
        SkipUntil(tok::r_brace);
        if (Tok.isOneOf(tok::comma, tok::l_brace, tok::kw_try)) {
          // This declaration isn't over yet. Keep skipping.
          continue;
        }
        TryConsumeToken(tok::semi);
        return;
  
      case tok::l_square:
        ConsumeBracket();
        SkipUntil(tok::r_square);
        continue;
  
      case tok::l_paren:
        ConsumeParen();
        SkipUntil(tok::r_paren);
        continue;
  
      case tok::r_brace:
        return;
  
      case tok::semi:
        ConsumeToken();
        return;
  
      case tok::kw_inline:
        // 'inline namespace' at the start of a line is almost certainly
        // a good place to pick back up parsing, except in an Objective-C
        // @interface context.
        if (Tok.isAtStartOfLine() && NextToken().is(tok::kw_namespace) &&
            (!ParsingInObjCContainer || CurParsedObjCImpl))
          return;
        break;
  
      case tok::kw_namespace:
        // 'namespace' at the start of a line is almost certainly a good
        // place to pick back up parsing, except in an Objective-C
        // @interface context.
        if (Tok.isAtStartOfLine() &&
            (!ParsingInObjCContainer || CurParsedObjCImpl))
          return;
        break;
  
      case tok::at:
        // @end is very much like } in Objective-C contexts.
        if (NextToken().isObjCAtKeyword(tok::objc_end) &&
            ParsingInObjCContainer)
          return;
        break;
  
      case tok::minus:
      case tok::plus:
        // - and + probably start new method declarations in Objective-C contexts.
        if (Tok.isAtStartOfLine() && ParsingInObjCContainer)
          return;
        break;
  
      case tok::eof:
      case tok::annot_module_begin:
      case tok::annot_module_end:
      case tok::annot_module_include:
        return;
  
      default:
        break;
      }
  
      ConsumeAnyToken();
    }
  }
  
  /// ParseDeclGroup - Having concluded that this is either a function
  /// definition or a group of object declarations, actually parse the
  /// result.
  Parser::DeclGroupPtrTy Parser::ParseDeclGroup(ParsingDeclSpec &DS,
                                                DeclaratorContext Context,
                                                SourceLocation *DeclEnd,
                                                ForRangeInit *FRI) {
    // Parse the first declarator.
    ParsingDeclarator D(*this, DS, Context);
    ParseDeclarator(D);
  
    // Bail out if the first declarator didn't seem well-formed.
    if (!D.hasName() && !D.mayOmitIdentifier()) {
      SkipMalformedDecl();
      return nullptr;
    }
  
    // Save late-parsed attributes for now; they need to be parsed in the
    // appropriate function scope after the function Decl has been constructed.
    // These will be parsed in ParseFunctionDefinition or ParseLexedAttrList.
    LateParsedAttrList LateParsedAttrs(true);
    if (D.isFunctionDeclarator()) {
      MaybeParseGNUAttributes(D, &LateParsedAttrs);
  
      // The _Noreturn keyword can't appear here, unlike the GNU noreturn
      // attribute. If we find the keyword here, tell the user to put it
      // at the start instead.
      if (Tok.is(tok::kw__Noreturn)) {
        SourceLocation Loc = ConsumeToken();
        const char *PrevSpec;
        unsigned DiagID;
  
        // We can offer a fixit if it's valid to mark this function as _Noreturn
        // and we don't have any other declarators in this declaration.
        bool Fixit = !DS.setFunctionSpecNoreturn(Loc, PrevSpec, DiagID);
        MaybeParseGNUAttributes(D, &LateParsedAttrs);
        Fixit &= Tok.isOneOf(tok::semi, tok::l_brace, tok::kw_try);
  
        Diag(Loc, diag::err_c11_noreturn_misplaced)
            << (Fixit ? FixItHint::CreateRemoval(Loc) : FixItHint())
            << (Fixit ? FixItHint::CreateInsertion(D.getBeginLoc(), "_Noreturn ")
                      : FixItHint());
      }
    }
  
    if (Tok.is(tok::kw_requires))
      ParseTrailingRequiresClause(D);
  
    // Check to see if we have a function *definition* which must have a body.
    if (D.isFunctionDeclarator() &&
        // Look at the next token to make sure that this isn't a function
        // declaration.  We have to check this because __attribute__ might be the
        // start of a function definition in GCC-extended K&R C.
        !isDeclarationAfterDeclarator()) {
  
      // Function definitions are only allowed at file scope and in C++ classes.
      // The C++ inline method definition case is handled elsewhere, so we only
      // need to handle the file scope definition case.
      if (Context == DeclaratorContext::FileContext) {
        if (isStartOfFunctionDefinition(D)) {
          if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
            Diag(Tok, diag::err_function_declared_typedef);
  
            // Recover by treating the 'typedef' as spurious.
            DS.ClearStorageClassSpecs();
          }
  
          Decl *TheDecl =
            ParseFunctionDefinition(D, ParsedTemplateInfo(), &LateParsedAttrs);
          return Actions.ConvertDeclToDeclGroup(TheDecl);
        }
  
        if (isDeclarationSpecifier()) {
          // If there is an invalid declaration specifier right after the
          // function prototype, then we must be in a missing semicolon case
          // where this isn't actually a body.  Just fall through into the code
          // that handles it as a prototype, and let the top-level code handle
          // the erroneous declspec where it would otherwise expect a comma or
          // semicolon.
        } else {
          Diag(Tok, diag::err_expected_fn_body);
          SkipUntil(tok::semi);
          return nullptr;
        }
      } else {
        if (Tok.is(tok::l_brace)) {
          Diag(Tok, diag::err_function_definition_not_allowed);
          SkipMalformedDecl();
          return nullptr;
        }
      }
    }
  
    if (ParseAsmAttributesAfterDeclarator(D))
      return nullptr;
  
    // C++0x [stmt.iter]p1: Check if we have a for-range-declarator. If so, we
    // must parse and analyze the for-range-initializer before the declaration is
    // analyzed.
    //
    // Handle the Objective-C for-in loop variable similarly, although we
    // don't need to parse the container in advance.
    if (FRI && (Tok.is(tok::colon) || isTokIdentifier_in())) {
      bool IsForRangeLoop = false;
      if (TryConsumeToken(tok::colon, FRI->ColonLoc)) {
        IsForRangeLoop = true;
        if (Tok.is(tok::l_brace))
          FRI->RangeExpr = ParseBraceInitializer();
        else
          FRI->RangeExpr = ParseExpression();
      }
  
      Decl *ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
      if (IsForRangeLoop) {
        Actions.ActOnCXXForRangeDecl(ThisDecl);
      } else {
        // Obj-C for loop
        if (auto *VD = dyn_cast_or_null<VarDecl>(ThisDecl))
          VD->setObjCForDecl(true);
      }
      Actions.FinalizeDeclaration(ThisDecl);
      D.complete(ThisDecl);
      return Actions.FinalizeDeclaratorGroup(getCurScope(), DS, ThisDecl);
    }
  
    SmallVector<Decl *, 8> DeclsInGroup;
    Decl *FirstDecl = ParseDeclarationAfterDeclaratorAndAttributes(
        D, ParsedTemplateInfo(), FRI);
    if (LateParsedAttrs.size() > 0)
      ParseLexedAttributeList(LateParsedAttrs, FirstDecl, true, false);
    D.complete(FirstDecl);
    if (FirstDecl)
      DeclsInGroup.push_back(FirstDecl);
  
    bool ExpectSemi = Context != DeclaratorContext::ForContext;
  
    // If we don't have a comma, it is either the end of the list (a ';') or an
    // error, bail out.
    SourceLocation CommaLoc;
    while (TryConsumeToken(tok::comma, CommaLoc)) {
      if (Tok.isAtStartOfLine() && ExpectSemi && !MightBeDeclarator(Context)) {
        // This comma was followed by a line-break and something which can't be
        // the start of a declarator. The comma was probably a typo for a
        // semicolon.
        Diag(CommaLoc, diag::err_expected_semi_declaration)
          << FixItHint::CreateReplacement(CommaLoc, ";");
        ExpectSemi = false;
        break;
      }
  
      // Parse the next declarator.
      D.clear();
      D.setCommaLoc(CommaLoc);
  
      // Accept attributes in an init-declarator.  In the first declarator in a
      // declaration, these would be part of the declspec.  In subsequent
      // declarators, they become part of the declarator itself, so that they
      // don't apply to declarators after *this* one.  Examples:
      //    short __attribute__((common)) var;    -> declspec
      //    short var __attribute__((common));    -> declarator
      //    short x, __attribute__((common)) var;    -> declarator
      MaybeParseGNUAttributes(D);
  
      // MSVC parses but ignores qualifiers after the comma as an extension.
      if (getLangOpts().MicrosoftExt)
        DiagnoseAndSkipExtendedMicrosoftTypeAttributes();
  
      ParseDeclarator(D);
      if (!D.isInvalidType()) {
        Decl *ThisDecl = ParseDeclarationAfterDeclarator(D);
        D.complete(ThisDecl);
        if (ThisDecl)
          DeclsInGroup.push_back(ThisDecl);
      }
    }
  
    if (DeclEnd)
      *DeclEnd = Tok.getLocation();
  
    if (ExpectSemi &&
        ExpectAndConsumeSemi(Context == DeclaratorContext::FileContext
                             ? diag::err_invalid_token_after_toplevel_declarator
                             : diag::err_expected_semi_declaration)) {
      // Okay, there was no semicolon and one was expected.  If we see a
      // declaration specifier, just assume it was missing and continue parsing.
      // Otherwise things are very confused and we skip to recover.
      if (!isDeclarationSpecifier()) {
        SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
        TryConsumeToken(tok::semi);
      }
    }
  
    return Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup);
  }
  
  /// Parse an optional simple-asm-expr and attributes, and attach them to a
  /// declarator. Returns true on an error.
  bool Parser::ParseAsmAttributesAfterDeclarator(Declarator &D) {
    // If a simple-asm-expr is present, parse it.
    if (Tok.is(tok::kw_asm)) {
      SourceLocation Loc;
      ExprResult AsmLabel(ParseSimpleAsm(&Loc));
      if (AsmLabel.isInvalid()) {
        SkipUntil(tok::semi, StopBeforeMatch);
        return true;
      }
  
      D.setAsmLabel(AsmLabel.get());
      D.SetRangeEnd(Loc);
    }
  
    MaybeParseGNUAttributes(D);
    return false;
  }
  
  /// Parse 'declaration' after parsing 'declaration-specifiers
  /// declarator'. This method parses the remainder of the declaration
  /// (including any attributes or initializer, among other things) and
  /// finalizes the declaration.
  ///
  ///       init-declarator: [C99 6.7]
  ///         declarator
  ///         declarator '=' initializer
  /// [GNU]   declarator simple-asm-expr[opt] attributes[opt]
  /// [GNU]   declarator simple-asm-expr[opt] attributes[opt] '=' initializer
  /// [C++]   declarator initializer[opt]
  ///
  /// [C++] initializer:
  /// [C++]   '=' initializer-clause
  /// [C++]   '(' expression-list ')'
  /// [C++0x] '=' 'default'                                                [TODO]
  /// [C++0x] '=' 'delete'
  /// [C++0x] braced-init-list
  ///
  /// According to the standard grammar, =default and =delete are function
  /// definitions, but that definitely doesn't fit with the parser here.
  ///
  Decl *Parser::ParseDeclarationAfterDeclarator(
      Declarator &D, const ParsedTemplateInfo &TemplateInfo) {
    if (ParseAsmAttributesAfterDeclarator(D))
      return nullptr;
  
    return ParseDeclarationAfterDeclaratorAndAttributes(D, TemplateInfo);
  }
  
  Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
      Declarator &D, const ParsedTemplateInfo &TemplateInfo, ForRangeInit *FRI) {
    // RAII type used to track whether we're inside an initializer.
    struct InitializerScopeRAII {
      Parser &P;
      Declarator &D;
      Decl *ThisDecl;
  
      InitializerScopeRAII(Parser &P, Declarator &D, Decl *ThisDecl)
          : P(P), D(D), ThisDecl(ThisDecl) {
        if (ThisDecl && P.getLangOpts().CPlusPlus) {
          Scope *S = nullptr;
          if (D.getCXXScopeSpec().isSet()) {
            P.EnterScope(0);
            S = P.getCurScope();
          }
          P.Actions.ActOnCXXEnterDeclInitializer(S, ThisDecl);
        }
      }
      ~InitializerScopeRAII() { pop(); }
      void pop() {
        if (ThisDecl && P.getLangOpts().CPlusPlus) {
          Scope *S = nullptr;
          if (D.getCXXScopeSpec().isSet())
            S = P.getCurScope();
          P.Actions.ActOnCXXExitDeclInitializer(S, ThisDecl);
          if (S)
            P.ExitScope();
        }
        ThisDecl = nullptr;
      }
    };
  
    // C++2a [dcl.decl]p1
    //    init-declarator:
    //	      declarator initializer[opt]
    //        declarator requires-clause
    if (Tok.is(tok::kw_requires))
      ParseTrailingRequiresClause(D);
  
    // Inform the current actions module that we just parsed this declarator.
    Decl *ThisDecl = nullptr;
    switch (TemplateInfo.Kind) {
    case ParsedTemplateInfo::NonTemplate:
      ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
      break;
  
    case ParsedTemplateInfo::Template:
    case ParsedTemplateInfo::ExplicitSpecialization: {
      ThisDecl = Actions.ActOnTemplateDeclarator(getCurScope(),
                                                 *TemplateInfo.TemplateParams,
                                                 D);
      if (VarTemplateDecl *VT = dyn_cast_or_null<VarTemplateDecl>(ThisDecl))
        // Re-direct this decl to refer to the templated decl so that we can
        // initialize it.
        ThisDecl = VT->getTemplatedDecl();
      break;
    }
    case ParsedTemplateInfo::ExplicitInstantiation: {
      if (Tok.is(tok::semi)) {
        DeclResult ThisRes = Actions.ActOnExplicitInstantiation(
            getCurScope(), TemplateInfo.ExternLoc, TemplateInfo.TemplateLoc, D);
        if (ThisRes.isInvalid()) {
          SkipUntil(tok::semi, StopBeforeMatch);
          return nullptr;
        }
        ThisDecl = ThisRes.get();
      } else {
        // FIXME: This check should be for a variable template instantiation only.
  
        // Check that this is a valid instantiation
        if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
          // If the declarator-id is not a template-id, issue a diagnostic and
          // recover by ignoring the 'template' keyword.
          Diag(Tok, diag::err_template_defn_explicit_instantiation)
              << 2 << FixItHint::CreateRemoval(TemplateInfo.TemplateLoc);
          ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
        } else {
          SourceLocation LAngleLoc =
              PP.getLocForEndOfToken(TemplateInfo.TemplateLoc);
          Diag(D.getIdentifierLoc(),
               diag::err_explicit_instantiation_with_definition)
              << SourceRange(TemplateInfo.TemplateLoc)
              << FixItHint::CreateInsertion(LAngleLoc, "<>");
  
          // Recover as if it were an explicit specialization.
          TemplateParameterLists FakedParamLists;
          FakedParamLists.push_back(Actions.ActOnTemplateParameterList(
              0, SourceLocation(), TemplateInfo.TemplateLoc, LAngleLoc, None,
              LAngleLoc, nullptr));
  
          ThisDecl =
              Actions.ActOnTemplateDeclarator(getCurScope(), FakedParamLists, D);
        }
      }
      break;
      }
    }
  
    // Parse declarator '=' initializer.
    // If a '==' or '+=' is found, suggest a fixit to '='.
    if (isTokenEqualOrEqualTypo()) {
      SourceLocation EqualLoc = ConsumeToken();
  
      if (Tok.is(tok::kw_delete)) {
        if (D.isFunctionDeclarator())
          Diag(ConsumeToken(), diag::err_default_delete_in_multiple_declaration)
            << 1 /* delete */;
        else
          Diag(ConsumeToken(), diag::err_deleted_non_function);
      } else if (Tok.is(tok::kw_default)) {
        if (D.isFunctionDeclarator())
          Diag(ConsumeToken(), diag::err_default_delete_in_multiple_declaration)
            << 0 /* default */;
        else
          Diag(ConsumeToken(), diag::err_default_special_members);
      } else {
        InitializerScopeRAII InitScope(*this, D, ThisDecl);
  
        if (Tok.is(tok::code_completion)) {
          Actions.CodeCompleteInitializer(getCurScope(), ThisDecl);
          Actions.FinalizeDeclaration(ThisDecl);
          cutOffParsing();
          return nullptr;
        }
  
        PreferredType.enterVariableInit(Tok.getLocation(), ThisDecl);
        ExprResult Init = ParseInitializer();
  
        // If this is the only decl in (possibly) range based for statement,
        // our best guess is that the user meant ':' instead of '='.
        if (Tok.is(tok::r_paren) && FRI && D.isFirstDeclarator()) {
          Diag(EqualLoc, diag::err_single_decl_assign_in_for_range)
              << FixItHint::CreateReplacement(EqualLoc, ":");
          // We are trying to stop parser from looking for ';' in this for
          // statement, therefore preventing spurious errors to be issued.
          FRI->ColonLoc = EqualLoc;
          Init = ExprError();
          FRI->RangeExpr = Init;
        }
  
        InitScope.pop();
  
        if (Init.isInvalid()) {
          SmallVector<tok::TokenKind, 2> StopTokens;
          StopTokens.push_back(tok::comma);
          if (D.getContext() == DeclaratorContext::ForContext ||
              D.getContext() == DeclaratorContext::InitStmtContext)
            StopTokens.push_back(tok::r_paren);
          SkipUntil(StopTokens, StopAtSemi | StopBeforeMatch);
          Actions.ActOnInitializerError(ThisDecl);
        } else
          Actions.AddInitializerToDecl(ThisDecl, Init.get(),
                                       /*DirectInit=*/false);
      }
    } else if (Tok.is(tok::l_paren)) {
      // Parse C++ direct initializer: '(' expression-list ')'
      BalancedDelimiterTracker T(*this, tok::l_paren);
      T.consumeOpen();
  
      ExprVector Exprs;
      CommaLocsTy CommaLocs;
  
      InitializerScopeRAII InitScope(*this, D, ThisDecl);
  
      auto ThisVarDecl = dyn_cast_or_null<VarDecl>(ThisDecl);
      auto RunSignatureHelp = [&]() {
        QualType PreferredType = Actions.ProduceConstructorSignatureHelp(
            getCurScope(), ThisVarDecl->getType()->getCanonicalTypeInternal(),
            ThisDecl->getLocation(), Exprs, T.getOpenLocation());
        CalledSignatureHelp = true;
        return PreferredType;
      };
      auto SetPreferredType = [&] {
        PreferredType.enterFunctionArgument(Tok.getLocation(), RunSignatureHelp);
      };
  
      llvm::function_ref<void()> ExpressionStarts;
      if (ThisVarDecl) {
        // ParseExpressionList can sometimes succeed even when ThisDecl is not
        // VarDecl. This is an error and it is reported in a call to
        // Actions.ActOnInitializerError(). However, we call
        // ProduceConstructorSignatureHelp only on VarDecls.
        ExpressionStarts = SetPreferredType;
      }
      if (ParseExpressionList(Exprs, CommaLocs, ExpressionStarts)) {
        if (ThisVarDecl && PP.isCodeCompletionReached() && !CalledSignatureHelp) {
          Actions.ProduceConstructorSignatureHelp(
              getCurScope(), ThisVarDecl->getType()->getCanonicalTypeInternal(),
              ThisDecl->getLocation(), Exprs, T.getOpenLocation());
          CalledSignatureHelp = true;
        }
        Actions.ActOnInitializerError(ThisDecl);
        SkipUntil(tok::r_paren, StopAtSemi);
      } else {
        // Match the ')'.
        T.consumeClose();
  
        assert(!Exprs.empty() && Exprs.size()-1 == CommaLocs.size() &&
               "Unexpected number of commas!");
  
        InitScope.pop();
  
        ExprResult Initializer = Actions.ActOnParenListExpr(T.getOpenLocation(),
                                                            T.getCloseLocation(),
                                                            Exprs);
        Actions.AddInitializerToDecl(ThisDecl, Initializer.get(),
                                     /*DirectInit=*/true);
      }
    } else if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace) &&
               (!CurParsedObjCImpl || !D.isFunctionDeclarator())) {
      // Parse C++0x braced-init-list.
      Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
  
      InitializerScopeRAII InitScope(*this, D, ThisDecl);
  
      ExprResult Init(ParseBraceInitializer());
  
      InitScope.pop();
  
      if (Init.isInvalid()) {
        Actions.ActOnInitializerError(ThisDecl);
      } else
        Actions.AddInitializerToDecl(ThisDecl, Init.get(), /*DirectInit=*/true);
  
    } else {
      Actions.ActOnUninitializedDecl(ThisDecl);
    }
  
    Actions.FinalizeDeclaration(ThisDecl);
  
    return ThisDecl;
  }
  
  /// ParseSpecifierQualifierList
  ///        specifier-qualifier-list:
  ///          type-specifier specifier-qualifier-list[opt]
  ///          type-qualifier specifier-qualifier-list[opt]
  /// [GNU]    attributes     specifier-qualifier-list[opt]
  ///
  void Parser::ParseSpecifierQualifierList(DeclSpec &DS, AccessSpecifier AS,
                                           DeclSpecContext DSC) {
    /// specifier-qualifier-list is a subset of declaration-specifiers.  Just
    /// parse declaration-specifiers and complain about extra stuff.
    /// TODO: diagnose attribute-specifiers and alignment-specifiers.
    ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS, DSC);
  
    // Validate declspec for type-name.
    unsigned Specs = DS.getParsedSpecifiers();
    if (isTypeSpecifier(DSC) && !DS.hasTypeSpecifier()) {
      Diag(Tok, diag::err_expected_type);
      DS.SetTypeSpecError();
    } else if (Specs == DeclSpec::PQ_None && !DS.hasAttributes()) {
      Diag(Tok, diag::err_typename_requires_specqual);
      if (!DS.hasTypeSpecifier())
        DS.SetTypeSpecError();
    }
  
    // Issue diagnostic and remove storage class if present.
    if (Specs & DeclSpec::PQ_StorageClassSpecifier) {
      if (DS.getStorageClassSpecLoc().isValid())
        Diag(DS.getStorageClassSpecLoc(),diag::err_typename_invalid_storageclass);
      else
        Diag(DS.getThreadStorageClassSpecLoc(),
             diag::err_typename_invalid_storageclass);
      DS.ClearStorageClassSpecs();
    }
  
    // Issue diagnostic and remove function specifier if present.
    if (Specs & DeclSpec::PQ_FunctionSpecifier) {
      if (DS.isInlineSpecified())
        Diag(DS.getInlineSpecLoc(), diag::err_typename_invalid_functionspec);
      if (DS.isVirtualSpecified())
        Diag(DS.getVirtualSpecLoc(), diag::err_typename_invalid_functionspec);
      if (DS.hasExplicitSpecifier())
        Diag(DS.getExplicitSpecLoc(), diag::err_typename_invalid_functionspec);
      DS.ClearFunctionSpecs();
    }
  
    // Issue diagnostic and remove constexpr specifier if present.
    if (DS.hasConstexprSpecifier() && DSC != DeclSpecContext::DSC_condition) {
      Diag(DS.getConstexprSpecLoc(), diag::err_typename_invalid_constexpr)
          << (DS.getConstexprSpecifier() == CSK_consteval);
      DS.ClearConstexprSpec();
    }
  }
  
  /// isValidAfterIdentifierInDeclaratorAfterDeclSpec - Return true if the
  /// specified token is valid after the identifier in a declarator which
  /// immediately follows the declspec.  For example, these things are valid:
  ///
  ///      int x   [             4];         // direct-declarator
  ///      int x   (             int y);     // direct-declarator
  ///  int(int x   )                         // direct-declarator
  ///      int x   ;                         // simple-declaration
  ///      int x   =             17;         // init-declarator-list
  ///      int x   ,             y;          // init-declarator-list
  ///      int x   __asm__       ("foo");    // init-declarator-list
  ///      int x   :             4;          // struct-declarator
  ///      int x   {             5};         // C++'0x unified initializers
  ///
  /// This is not, because 'x' does not immediately follow the declspec (though
  /// ')' happens to be valid anyway).
  ///    int (x)
  ///
  static bool isValidAfterIdentifierInDeclarator(const Token &T) {
    return T.isOneOf(tok::l_square, tok::l_paren, tok::r_paren, tok::semi,
                     tok::comma, tok::equal, tok::kw_asm, tok::l_brace,
                     tok::colon);
  }
  
  /// ParseImplicitInt - This method is called when we have an non-typename
  /// identifier in a declspec (which normally terminates the decl spec) when
  /// the declspec has no type specifier.  In this case, the declspec is either
  /// malformed or is "implicit int" (in K&R and C89).
  ///
  /// This method handles diagnosing this prettily and returns false if the
  /// declspec is done being processed.  If it recovers and thinks there may be
  /// other pieces of declspec after it, it returns true.
  ///
  bool Parser::ParseImplicitInt(DeclSpec &DS, CXXScopeSpec *SS,
                                const ParsedTemplateInfo &TemplateInfo,
                                AccessSpecifier AS, DeclSpecContext DSC,
                                ParsedAttributesWithRange &Attrs) {
    assert(Tok.is(tok::identifier) && "should have identifier");
  
    SourceLocation Loc = Tok.getLocation();
    // If we see an identifier that is not a type name, we normally would
    // parse it as the identifier being declared.  However, when a typename
    // is typo'd or the definition is not included, this will incorrectly
    // parse the typename as the identifier name and fall over misparsing
    // later parts of the diagnostic.
    //
    // As such, we try to do some look-ahead in cases where this would
    // otherwise be an "implicit-int" case to see if this is invalid.  For
    // example: "static foo_t x = 4;"  In this case, if we parsed foo_t as
    // an identifier with implicit int, we'd get a parse error because the
    // next token is obviously invalid for a type.  Parse these as a case
    // with an invalid type specifier.
    assert(!DS.hasTypeSpecifier() && "Type specifier checked above");
  
    // Since we know that this either implicit int (which is rare) or an
    // error, do lookahead to try to do better recovery. This never applies
    // within a type specifier. Outside of C++, we allow this even if the
    // language doesn't "officially" support implicit int -- we support
    // implicit int as an extension in C99 and C11.
    if (!isTypeSpecifier(DSC) && !getLangOpts().CPlusPlus &&
        isValidAfterIdentifierInDeclarator(NextToken())) {
      // If this token is valid for implicit int, e.g. "static x = 4", then
      // we just avoid eating the identifier, so it will be parsed as the
      // identifier in the declarator.
      return false;
    }
  
    // Early exit as Sema has a dedicated missing_actual_pipe_type diagnostic
    // for incomplete declarations such as `pipe p`.
    if (getLangOpts().OpenCLCPlusPlus && DS.isTypeSpecPipe())
      return false;
  
    if (getLangOpts().CPlusPlus &&
        DS.getStorageClassSpec() == DeclSpec::SCS_auto) {
      // Don't require a type specifier if we have the 'auto' storage class
      // specifier in C++98 -- we'll promote it to a type specifier.
      if (SS)
        AnnotateScopeToken(*SS, /*IsNewAnnotation*/false);
      return false;
    }
  
    if (getLangOpts().CPlusPlus && (!SS || SS->isEmpty()) &&
        getLangOpts().MSVCCompat) {
      // Lookup of an unqualified type name has failed in MSVC compatibility mode.
      // Give Sema a chance to recover if we are in a template with dependent base
      // classes.
      if (ParsedType T = Actions.ActOnMSVCUnknownTypeName(
              *Tok.getIdentifierInfo(), Tok.getLocation(),
              DSC == DeclSpecContext::DSC_template_type_arg)) {
        const char *PrevSpec;
        unsigned DiagID;
        DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec, DiagID, T,
                           Actions.getASTContext().getPrintingPolicy());
        DS.SetRangeEnd(Tok.getLocation());
        ConsumeToken();
        return false;
      }
    }
  
    // Otherwise, if we don't consume this token, we are going to emit an
    // error anyway.  Try to recover from various common problems.  Check
    // to see if this was a reference to a tag name without a tag specified.
    // This is a common problem in C (saying 'foo' instead of 'struct foo').
    //
    // C++ doesn't need this, and isTagName doesn't take SS.
    if (SS == nullptr) {
      const char *TagName = nullptr, *FixitTagName = nullptr;
      tok::TokenKind TagKind = tok::unknown;
  
      switch (Actions.isTagName(*Tok.getIdentifierInfo(), getCurScope())) {
        default: break;
        case DeclSpec::TST_enum:
          TagName="enum"  ; FixitTagName = "enum "  ; TagKind=tok::kw_enum ;break;
        case DeclSpec::TST_union:
          TagName="union" ; FixitTagName = "union " ;TagKind=tok::kw_union ;break;
        case DeclSpec::TST_struct:
          TagName="struct"; FixitTagName = "struct ";TagKind=tok::kw_struct;break;
        case DeclSpec::TST_interface:
          TagName="__interface"; FixitTagName = "__interface ";
          TagKind=tok::kw___interface;break;
        case DeclSpec::TST_class:
          TagName="class" ; FixitTagName = "class " ;TagKind=tok::kw_class ;break;
      }
  
      if (TagName) {
        IdentifierInfo *TokenName = Tok.getIdentifierInfo();
        LookupResult R(Actions, TokenName, SourceLocation(),
                       Sema::LookupOrdinaryName);
  
        Diag(Loc, diag::err_use_of_tag_name_without_tag)
          << TokenName << TagName << getLangOpts().CPlusPlus
          << FixItHint::CreateInsertion(Tok.getLocation(), FixitTagName);
  
        if (Actions.LookupParsedName(R, getCurScope(), SS)) {
          for (LookupResult::iterator I = R.begin(), IEnd = R.end();
               I != IEnd; ++I)
            Diag((*I)->getLocation(), diag::note_decl_hiding_tag_type)
              << TokenName << TagName;
        }
  
        // Parse this as a tag as if the missing tag were present.
        if (TagKind == tok::kw_enum)
          ParseEnumSpecifier(Loc, DS, TemplateInfo, AS,
                             DeclSpecContext::DSC_normal);
        else
          ParseClassSpecifier(TagKind, Loc, DS, TemplateInfo, AS,
                              /*EnteringContext*/ false,
                              DeclSpecContext::DSC_normal, Attrs);
        return true;
      }
    }
  
    // Determine whether this identifier could plausibly be the name of something
    // being declared (with a missing type).
    if (!isTypeSpecifier(DSC) && (!SS || DSC == DeclSpecContext::DSC_top_level ||
                                  DSC == DeclSpecContext::DSC_class)) {
      // Look ahead to the next token to try to figure out what this declaration
      // was supposed to be.
      switch (NextToken().getKind()) {
      case tok::l_paren: {
        // static x(4); // 'x' is not a type
        // x(int n);    // 'x' is not a type
        // x (*p)[];    // 'x' is a type
        //
        // Since we're in an error case, we can afford to perform a tentative
        // parse to determine which case we're in.
        TentativeParsingAction PA(*this);
        ConsumeToken();
        TPResult TPR = TryParseDeclarator(/*mayBeAbstract*/false);
        PA.Revert();
  
        if (TPR != TPResult::False) {
          // The identifier is followed by a parenthesized declarator.
          // It's supposed to be a type.
          break;
        }
  
        // If we're in a context where we could be declaring a constructor,
        // check whether this is a constructor declaration with a bogus name.
        if (DSC == DeclSpecContext::DSC_class ||
            (DSC == DeclSpecContext::DSC_top_level && SS)) {
          IdentifierInfo *II = Tok.getIdentifierInfo();
          if (Actions.isCurrentClassNameTypo(II, SS)) {
            Diag(Loc, diag::err_constructor_bad_name)
              << Tok.getIdentifierInfo() << II
              << FixItHint::CreateReplacement(Tok.getLocation(), II->getName());
            Tok.setIdentifierInfo(II);
          }
        }
        // Fall through.
        LLVM_FALLTHROUGH;
      }
      case tok::comma:
      case tok::equal:
      case tok::kw_asm:
      case tok::l_brace:
      case tok::l_square:
      case tok::semi:
        // This looks like a variable or function declaration. The type is
        // probably missing. We're done parsing decl-specifiers.
        // But only if we are not in a function prototype scope.
        if (getCurScope()->isFunctionPrototypeScope())
          break;
        if (SS)
          AnnotateScopeToken(*SS, /*IsNewAnnotation*/false);
        return false;
  
      default:
        // This is probably supposed to be a type. This includes cases like:
        //   int f(itn);
        //   struct S { unsinged : 4; };
        break;
      }
    }
  
    // This is almost certainly an invalid type name. Let Sema emit a diagnostic
    // and attempt to recover.
    ParsedType T;
    IdentifierInfo *II = Tok.getIdentifierInfo();
    bool IsTemplateName = getLangOpts().CPlusPlus && NextToken().is(tok::less);
    Actions.DiagnoseUnknownTypeName(II, Loc, getCurScope(), SS, T,
                                    IsTemplateName);
    if (T) {
      // The action has suggested that the type T could be used. Set that as
      // the type in the declaration specifiers, consume the would-be type
      // name token, and we're done.
      const char *PrevSpec;
      unsigned DiagID;
      DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec, DiagID, T,
                         Actions.getASTContext().getPrintingPolicy());
      DS.SetRangeEnd(Tok.getLocation());
      ConsumeToken();
      // There may be other declaration specifiers after this.
      return true;
    } else if (II != Tok.getIdentifierInfo()) {
      // If no type was suggested, the correction is to a keyword
      Tok.setKind(II->getTokenID());
      // There may be other declaration specifiers after this.
      return true;
    }
  
    // Otherwise, the action had no suggestion for us.  Mark this as an error.
    DS.SetTypeSpecError();
    DS.SetRangeEnd(Tok.getLocation());
    ConsumeToken();
  
    // Eat any following template arguments.
    if (IsTemplateName) {
      SourceLocation LAngle, RAngle;
      TemplateArgList Args;
      ParseTemplateIdAfterTemplateName(true, LAngle, Args, RAngle);
    }
  
    // TODO: Could inject an invalid typedef decl in an enclosing scope to
    // avoid rippling error messages on subsequent uses of the same type,
    // could be useful if #include was forgotten.
    return true;
  }
  
  /// Determine the declaration specifier context from the declarator
  /// context.
  ///
  /// \param Context the declarator context, which is one of the
  /// DeclaratorContext enumerator values.
  Parser::DeclSpecContext
  Parser::getDeclSpecContextFromDeclaratorContext(DeclaratorContext Context) {
    if (Context == DeclaratorContext::MemberContext)
      return DeclSpecContext::DSC_class;
    if (Context == DeclaratorContext::FileContext)
      return DeclSpecContext::DSC_top_level;
    if (Context == DeclaratorContext::TemplateParamContext)
      return DeclSpecContext::DSC_template_param;
    if (Context == DeclaratorContext::TemplateArgContext ||
        Context == DeclaratorContext::TemplateTypeArgContext)
      return DeclSpecContext::DSC_template_type_arg;
    if (Context == DeclaratorContext::TrailingReturnContext ||
        Context == DeclaratorContext::TrailingReturnVarContext)
      return DeclSpecContext::DSC_trailing;
    if (Context == DeclaratorContext::AliasDeclContext ||
        Context == DeclaratorContext::AliasTemplateContext)
      return DeclSpecContext::DSC_alias_declaration;
    return DeclSpecContext::DSC_normal;
  }
  
  /// ParseAlignArgument - Parse the argument to an alignment-specifier.
  ///
  /// FIXME: Simply returns an alignof() expression if the argument is a
  /// type. Ideally, the type should be propagated directly into Sema.
  ///
  /// [C11]   type-id
  /// [C11]   constant-expression
  /// [C++0x] type-id ...[opt]
  /// [C++0x] assignment-expression ...[opt]
  ExprResult Parser::ParseAlignArgument(SourceLocation Start,
                                        SourceLocation &EllipsisLoc) {
    ExprResult ER;
    if (isTypeIdInParens()) {
      SourceLocation TypeLoc = Tok.getLocation();
      ParsedType Ty = ParseTypeName().get();
      SourceRange TypeRange(Start, Tok.getLocation());
      ER = Actions.ActOnUnaryExprOrTypeTraitExpr(TypeLoc, UETT_AlignOf, true,
                                                 Ty.getAsOpaquePtr(), TypeRange);
    } else
      ER = ParseConstantExpression();
  
    if (getLangOpts().CPlusPlus11)
      TryConsumeToken(tok::ellipsis, EllipsisLoc);
  
    return ER;
  }
  
  /// ParseAlignmentSpecifier - Parse an alignment-specifier, and add the
  /// attribute to Attrs.
  ///
  /// alignment-specifier:
  /// [C11]   '_Alignas' '(' type-id ')'
  /// [C11]   '_Alignas' '(' constant-expression ')'
  /// [C++11] 'alignas' '(' type-id ...[opt] ')'
  /// [C++11] 'alignas' '(' assignment-expression ...[opt] ')'
  void Parser::ParseAlignmentSpecifier(ParsedAttributes &Attrs,
                                       SourceLocation *EndLoc) {
    assert(Tok.isOneOf(tok::kw_alignas, tok::kw__Alignas) &&
           "Not an alignment-specifier!");
  
    IdentifierInfo *KWName = Tok.getIdentifierInfo();
    SourceLocation KWLoc = ConsumeToken();
  
    BalancedDelimiterTracker T(*this, tok::l_paren);
    if (T.expectAndConsume())
      return;
  
    SourceLocation EllipsisLoc;
    ExprResult ArgExpr = ParseAlignArgument(T.getOpenLocation(), EllipsisLoc);
    if (ArgExpr.isInvalid()) {
      T.skipToEnd();
      return;
    }
  
    T.consumeClose();
    if (EndLoc)
      *EndLoc = T.getCloseLocation();
  
    ArgsVector ArgExprs;
    ArgExprs.push_back(ArgExpr.get());
    Attrs.addNew(KWName, KWLoc, nullptr, KWLoc, ArgExprs.data(), 1,
                 ParsedAttr::AS_Keyword, EllipsisLoc);
  }
  
  /// Determine whether we're looking at something that might be a declarator
  /// in a simple-declaration. If it can't possibly be a declarator, maybe
  /// diagnose a missing semicolon after a prior tag definition in the decl
  /// specifier.
  ///
  /// \return \c true if an error occurred and this can't be any kind of
  /// declaration.
  bool
  Parser::DiagnoseMissingSemiAfterTagDefinition(DeclSpec &DS, AccessSpecifier AS,
                                                DeclSpecContext DSContext,
                                                LateParsedAttrList *LateAttrs) {
    assert(DS.hasTagDefinition() && "shouldn't call this");
  
    bool EnteringContext = (DSContext == DeclSpecContext::DSC_class ||
                            DSContext == DeclSpecContext::DSC_top_level);
  
    if (getLangOpts().CPlusPlus &&
        Tok.isOneOf(tok::identifier, tok::coloncolon, tok::kw_decltype,
                    tok::annot_template_id) &&
        TryAnnotateCXXScopeToken(EnteringContext)) {
      SkipMalformedDecl();
      return true;
    }
  
    bool HasScope = Tok.is(tok::annot_cxxscope);
    // Make a copy in case GetLookAheadToken invalidates the result of NextToken.
    Token AfterScope = HasScope ? NextToken() : Tok;
  
    // Determine whether the following tokens could possibly be a
    // declarator.
    bool MightBeDeclarator = true;
    if (Tok.isOneOf(tok::kw_typename, tok::annot_typename)) {
      // A declarator-id can't start with 'typename'.
      MightBeDeclarator = false;
    } else if (AfterScope.is(tok::annot_template_id)) {
      // If we have a type expressed as a template-id, this cannot be a
      // declarator-id (such a type cannot be redeclared in a simple-declaration).
      TemplateIdAnnotation *Annot =
          static_cast<TemplateIdAnnotation *>(AfterScope.getAnnotationValue());
      if (Annot->Kind == TNK_Type_template)
        MightBeDeclarator = false;
    } else if (AfterScope.is(tok::identifier)) {
      const Token &Next = HasScope ? GetLookAheadToken(2) : NextToken();
  
      // These tokens cannot come after the declarator-id in a
      // simple-declaration, and are likely to come after a type-specifier.
      if (Next.isOneOf(tok::star, tok::amp, tok::ampamp, tok::identifier,
                       tok::annot_cxxscope, tok::coloncolon)) {
        // Missing a semicolon.
        MightBeDeclarator = false;
      } else if (HasScope) {
        // If the declarator-id has a scope specifier, it must redeclare a
        // previously-declared entity. If that's a type (and this is not a
        // typedef), that's an error.
        CXXScopeSpec SS;
        Actions.RestoreNestedNameSpecifierAnnotation(
            Tok.getAnnotationValue(), Tok.getAnnotationRange(), SS);
        IdentifierInfo *Name = AfterScope.getIdentifierInfo();
        Sema::NameClassification Classification = Actions.ClassifyName(
            getCurScope(), SS, Name, AfterScope.getLocation(), Next,
            /*IsAddressOfOperand=*/false, /*CCC=*/nullptr);
        switch (Classification.getKind()) {
        case Sema::NC_Error:
          SkipMalformedDecl();
          return true;
  
        case Sema::NC_Keyword:
        case Sema::NC_NestedNameSpecifier:
          llvm_unreachable("typo correction and nested name specifiers not "
                           "possible here");
  
        case Sema::NC_Type:
        case Sema::NC_TypeTemplate:
          // Not a previously-declared non-type entity.
          MightBeDeclarator = false;
          break;
  
        case Sema::NC_Unknown:
        case Sema::NC_Expression:
        case Sema::NC_VarTemplate:
        case Sema::NC_FunctionTemplate:
        case Sema::NC_UndeclaredTemplate:
          // Might be a redeclaration of a prior entity.
          break;
        }
      }
    }
  
    if (MightBeDeclarator)
      return false;
  
    const PrintingPolicy &PPol = Actions.getASTContext().getPrintingPolicy();
    Diag(PP.getLocForEndOfToken(DS.getRepAsDecl()->getEndLoc()),
         diag::err_expected_after)
        << DeclSpec::getSpecifierName(DS.getTypeSpecType(), PPol) << tok::semi;
  
    // Try to recover from the typo, by dropping the tag definition and parsing
    // the problematic tokens as a type.
    //
    // FIXME: Split the DeclSpec into pieces for the standalone
    // declaration and pieces for the following declaration, instead
    // of assuming that all the other pieces attach to new declaration,
    // and call ParsedFreeStandingDeclSpec as appropriate.
    DS.ClearTypeSpecType();
    ParsedTemplateInfo NotATemplate;
    ParseDeclarationSpecifiers(DS, NotATemplate, AS, DSContext, LateAttrs);
    return false;
  }
  
  // Choose the apprpriate diagnostic error for why fixed point types are
  // disabled, set the previous specifier, and mark as invalid.
  static void SetupFixedPointError(const LangOptions &LangOpts,
                                   const char *&PrevSpec, unsigned &DiagID,
                                   bool &isInvalid) {
    assert(!LangOpts.FixedPoint);
    DiagID = diag::err_fixed_point_not_enabled;
    PrevSpec = "";  // Not used by diagnostic
    isInvalid = true;
  }
  
  /// ParseDeclarationSpecifiers
  ///       declaration-specifiers: [C99 6.7]
  ///         storage-class-specifier declaration-specifiers[opt]
  ///         type-specifier declaration-specifiers[opt]
  /// [C99]   function-specifier declaration-specifiers[opt]
  /// [C11]   alignment-specifier declaration-specifiers[opt]
  /// [GNU]   attributes declaration-specifiers[opt]
  /// [Clang] '__module_private__' declaration-specifiers[opt]
  /// [ObjC1] '__kindof' declaration-specifiers[opt]
  ///
  ///       storage-class-specifier: [C99 6.7.1]
  ///         'typedef'
  ///         'extern'
  ///         'static'
  ///         'auto'
  ///         'register'
  /// [C++]   'mutable'
  /// [C++11] 'thread_local'
  /// [C11]   '_Thread_local'
  /// [GNU]   '__thread'
  ///       function-specifier: [C99 6.7.4]
  /// [C99]   'inline'
  /// [C++]   'virtual'
  /// [C++]   'explicit'
  /// [OpenCL] '__kernel'
  ///       'friend': [C++ dcl.friend]
  ///       'constexpr': [C++0x dcl.constexpr]
  void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
                                          const ParsedTemplateInfo &TemplateInfo,
                                          AccessSpecifier AS,
                                          DeclSpecContext DSContext,
                                          LateParsedAttrList *LateAttrs) {
    if (DS.getSourceRange().isInvalid()) {
      // Start the range at the current token but make the end of the range
      // invalid.  This will make the entire range invalid unless we successfully
      // consume a token.
      DS.SetRangeStart(Tok.getLocation());
      DS.SetRangeEnd(SourceLocation());
    }
  
    bool EnteringContext = (DSContext == DeclSpecContext::DSC_class ||
                            DSContext == DeclSpecContext::DSC_top_level);
    bool AttrsLastTime = false;
    ParsedAttributesWithRange attrs(AttrFactory);
    // We use Sema's policy to get bool macros right.
    PrintingPolicy Policy = Actions.getPrintingPolicy();
    while (1) {
      bool isInvalid = false;
      bool isStorageClass = false;
      const char *PrevSpec = nullptr;
      unsigned DiagID = 0;
  
      // This value needs to be set to the location of the last token if the last
      // token of the specifier is already consumed.
      SourceLocation ConsumedEnd;
  
      // HACK: MSVC doesn't consider _Atomic to be a keyword and its STL
      // implementation for VS2013 uses _Atomic as an identifier for one of the
      // classes in <atomic>.
      //
      // A typedef declaration containing _Atomic<...> is among the places where
      // the class is used.  If we are currently parsing such a declaration, treat
      // the token as an identifier.
      if (getLangOpts().MSVCCompat && Tok.is(tok::kw__Atomic) &&
          DS.getStorageClassSpec() == clang::DeclSpec::SCS_typedef &&
          !DS.hasTypeSpecifier() && GetLookAheadToken(1).is(tok::less))
        Tok.setKind(tok::identifier);
  
      SourceLocation Loc = Tok.getLocation();
  
      switch (Tok.getKind()) {
      default:
      DoneWithDeclSpec:
        if (!AttrsLastTime)
          ProhibitAttributes(attrs);
        else {
          // Reject C++11 attributes that appertain to decl specifiers as
          // we don't support any C++11 attributes that appertain to decl
          // specifiers. This also conforms to what g++ 4.8 is doing.
          ProhibitCXX11Attributes(attrs, diag::err_attribute_not_type_attr);
  
          DS.takeAttributesFrom(attrs);
        }
  
        // If this is not a declaration specifier token, we're done reading decl
        // specifiers.  First verify that DeclSpec's are consistent.
        DS.Finish(Actions, Policy);
        return;
  
      case tok::l_square:
      case tok::kw_alignas:
        if (!standardAttributesAllowed() || !isCXX11AttributeSpecifier())
          goto DoneWithDeclSpec;
  
        ProhibitAttributes(attrs);
        // FIXME: It would be good to recover by accepting the attributes,
        //        but attempting to do that now would cause serious
        //        madness in terms of diagnostics.
        attrs.clear();
        attrs.Range = SourceRange();
  
        ParseCXX11Attributes(attrs);
        AttrsLastTime = true;
        continue;
  
      case tok::code_completion: {
        Sema::ParserCompletionContext CCC = Sema::PCC_Namespace;
        if (DS.hasTypeSpecifier()) {
          bool AllowNonIdentifiers
            = (getCurScope()->getFlags() & (Scope::ControlScope |
                                            Scope::BlockScope |
                                            Scope::TemplateParamScope |
                                            Scope::FunctionPrototypeScope |
                                            Scope::AtCatchScope)) == 0;
          bool AllowNestedNameSpecifiers
            = DSContext == DeclSpecContext::DSC_top_level ||
              (DSContext == DeclSpecContext::DSC_class && DS.isFriendSpecified());
  
          Actions.CodeCompleteDeclSpec(getCurScope(), DS,
                                       AllowNonIdentifiers,
                                       AllowNestedNameSpecifiers);
          return cutOffParsing();
        }
  
        if (getCurScope()->getFnParent() || getCurScope()->getBlockParent())
          CCC = Sema::PCC_LocalDeclarationSpecifiers;
        else if (TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate)
          CCC = DSContext == DeclSpecContext::DSC_class ? Sema::PCC_MemberTemplate
                                                        : Sema::PCC_Template;
        else if (DSContext == DeclSpecContext::DSC_class)
          CCC = Sema::PCC_Class;
        else if (CurParsedObjCImpl)
          CCC = Sema::PCC_ObjCImplementation;
  
        Actions.CodeCompleteOrdinaryName(getCurScope(), CCC);
        return cutOffParsing();
      }
  
      case tok::coloncolon: // ::foo::bar
        // C++ scope specifier.  Annotate and loop, or bail out on error.
        if (TryAnnotateCXXScopeToken(EnteringContext)) {
          if (!DS.hasTypeSpecifier())
            DS.SetTypeSpecError();
          goto DoneWithDeclSpec;
        }
        if (Tok.is(tok::coloncolon)) // ::new or ::delete
          goto DoneWithDeclSpec;
        continue;
  
      case tok::annot_cxxscope: {
        if (DS.hasTypeSpecifier() || DS.isTypeAltiVecVector())
          goto DoneWithDeclSpec;
  
        CXXScopeSpec SS;
        Actions.RestoreNestedNameSpecifierAnnotation(Tok.getAnnotationValue(),
                                                     Tok.getAnnotationRange(),
                                                     SS);
  
        // We are looking for a qualified typename.
        Token Next = NextToken();
        if (Next.is(tok::annot_template_id) &&
            static_cast<TemplateIdAnnotation *>(Next.getAnnotationValue())
              ->Kind == TNK_Type_template) {
          // We have a qualified template-id, e.g., N::A<int>
  
          // If this would be a valid constructor declaration with template
          // arguments, we will reject the attempt to form an invalid type-id
          // referring to the injected-class-name when we annotate the token,
          // per C++ [class.qual]p2.
          //
          // To improve diagnostics for this case, parse the declaration as a
          // constructor (and reject the extra template arguments later).
          TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Next);
          if ((DSContext == DeclSpecContext::DSC_top_level ||
               DSContext == DeclSpecContext::DSC_class) &&
              TemplateId->Name &&
              Actions.isCurrentClassName(*TemplateId->Name, getCurScope(), &SS) &&
              isConstructorDeclarator(/*Unqualified*/ false)) {
            // The user meant this to be an out-of-line constructor
            // definition, but template arguments are not allowed
            // there.  Just allow this as a constructor; we'll
            // complain about it later.
            goto DoneWithDeclSpec;
          }
  
          DS.getTypeSpecScope() = SS;
          ConsumeAnnotationToken(); // The C++ scope.
          assert(Tok.is(tok::annot_template_id) &&
                 "ParseOptionalCXXScopeSpecifier not working");
          AnnotateTemplateIdTokenAsType();
          continue;
        }
  
        if (Next.is(tok::annot_typename)) {
          DS.getTypeSpecScope() = SS;
          ConsumeAnnotationToken(); // The C++ scope.
          if (Tok.getAnnotationValue()) {
            ParsedType T = getTypeAnnotation(Tok);
            isInvalid = DS.SetTypeSpecType(DeclSpec::TST_typename,
                                           Tok.getAnnotationEndLoc(),
                                           PrevSpec, DiagID, T, Policy);
            if (isInvalid)
              break;
          }
          else
            DS.SetTypeSpecError();
          DS.SetRangeEnd(Tok.getAnnotationEndLoc());
          ConsumeAnnotationToken(); // The typename
        }
  
        if (Next.isNot(tok::identifier))
          goto DoneWithDeclSpec;
  
        // Check whether this is a constructor declaration. If we're in a
        // context where the identifier could be a class name, and it has the
        // shape of a constructor declaration, process it as one.
        if ((DSContext == DeclSpecContext::DSC_top_level ||
             DSContext == DeclSpecContext::DSC_class) &&
            Actions.isCurrentClassName(*Next.getIdentifierInfo(), getCurScope(),
                                       &SS) &&
            isConstructorDeclarator(/*Unqualified*/ false))
          goto DoneWithDeclSpec;
  
        ParsedType TypeRep =
            Actions.getTypeName(*Next.getIdentifierInfo(), Next.getLocation(),
                                getCurScope(), &SS, false, false, nullptr,
                                /*IsCtorOrDtorName=*/false,
                                /*WantNonTrivialSourceInfo=*/true,
                                isClassTemplateDeductionContext(DSContext));
  
        // If the referenced identifier is not a type, then this declspec is
        // erroneous: We already checked about that it has no type specifier, and
        // C++ doesn't have implicit int.  Diagnose it as a typo w.r.t. to the
        // typename.
        if (!TypeRep) {
          if (TryAnnotateTypeConstraint(SS))
            continue;
          // Eat the scope spec so the identifier is current.
          ConsumeAnnotationToken();
          ParsedAttributesWithRange Attrs(AttrFactory);
          if (ParseImplicitInt(DS, &SS, TemplateInfo, AS, DSContext, Attrs)) {
            if (!Attrs.empty()) {
              AttrsLastTime = true;
              attrs.takeAllFrom(Attrs);
            }
            continue;
          }
          goto DoneWithDeclSpec;
        }
  
        DS.getTypeSpecScope() = SS;
        ConsumeAnnotationToken(); // The C++ scope.
  
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec,
                                       DiagID, TypeRep, Policy);
        if (isInvalid)
          break;
  
        DS.SetRangeEnd(Tok.getLocation());
        ConsumeToken(); // The typename.
  
        continue;
      }
  
      case tok::annot_typename: {
        // If we've previously seen a tag definition, we were almost surely
        // missing a semicolon after it.
        if (DS.hasTypeSpecifier() && DS.hasTagDefinition())
          goto DoneWithDeclSpec;
  
        if (Tok.getAnnotationValue()) {
          ParsedType T = getTypeAnnotation(Tok);
          isInvalid = DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec,
                                         DiagID, T, Policy);
        } else
          DS.SetTypeSpecError();
  
        if (isInvalid)
          break;
  
        DS.SetRangeEnd(Tok.getAnnotationEndLoc());
        ConsumeAnnotationToken(); // The typename
  
        continue;
      }
  
      case tok::kw___is_signed:
        // GNU libstdc++ 4.4 uses __is_signed as an identifier, but Clang
        // typically treats it as a trait. If we see __is_signed as it appears
        // in libstdc++, e.g.,
        //
        //   static const bool __is_signed;
        //
        // then treat __is_signed as an identifier rather than as a keyword.
        if (DS.getTypeSpecType() == TST_bool &&
            DS.getTypeQualifiers() == DeclSpec::TQ_const &&
            DS.getStorageClassSpec() == DeclSpec::SCS_static)
          TryKeywordIdentFallback(true);
  
        // We're done with the declaration-specifiers.
        goto DoneWithDeclSpec;
  
        // typedef-name
      case tok::kw___super:
      case tok::kw_decltype:
      case tok::identifier: {
        // This identifier can only be a typedef name if we haven't already seen
        // a type-specifier.  Without this check we misparse:
        //  typedef int X; struct Y { short X; };  as 'short int'.
        if (DS.hasTypeSpecifier())
          goto DoneWithDeclSpec;
  
        // If the token is an identifier named "__declspec" and Microsoft
        // extensions are not enabled, it is likely that there will be cascading
        // parse errors if this really is a __declspec attribute. Attempt to
        // recognize that scenario and recover gracefully.
        if (!getLangOpts().DeclSpecKeyword && Tok.is(tok::identifier) &&
            Tok.getIdentifierInfo()->getName().equals("__declspec")) {
          Diag(Loc, diag::err_ms_attributes_not_enabled);
  
          // The next token should be an open paren. If it is, eat the entire
          // attribute declaration and continue.
          if (NextToken().is(tok::l_paren)) {
            // Consume the __declspec identifier.
            ConsumeToken();
  
            // Eat the parens and everything between them.
            BalancedDelimiterTracker T(*this, tok::l_paren);
            if (T.consumeOpen()) {
              assert(false && "Not a left paren?");
              return;
            }
            T.skipToEnd();
            continue;
          }
        }
  
        // In C++, check to see if this is a scope specifier like foo::bar::, if
        // so handle it as such.  This is important for ctor parsing.
        if (getLangOpts().CPlusPlus) {
          if (TryAnnotateCXXScopeToken(EnteringContext)) {
            DS.SetTypeSpecError();
            goto DoneWithDeclSpec;
          }
          if (!Tok.is(tok::identifier))
            continue;
        }
  
        // Check for need to substitute AltiVec keyword tokens.
        if (TryAltiVecToken(DS, Loc, PrevSpec, DiagID, isInvalid))
          break;
  
        // [AltiVec] 2.2: [If the 'vector' specifier is used] The syntax does not
        //                allow the use of a typedef name as a type specifier.
        if (DS.isTypeAltiVecVector())
          goto DoneWithDeclSpec;
  
        if (DSContext == DeclSpecContext::DSC_objc_method_result &&
            isObjCInstancetype()) {
          ParsedType TypeRep = Actions.ActOnObjCInstanceType(Loc);
          assert(TypeRep);
          isInvalid = DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec,
                                         DiagID, TypeRep, Policy);
          if (isInvalid)
            break;
  
          DS.SetRangeEnd(Loc);
          ConsumeToken();
          continue;
        }
  
        // If we're in a context where the identifier could be a class name,
        // check whether this is a constructor declaration.
        if (getLangOpts().CPlusPlus && DSContext == DeclSpecContext::DSC_class &&
            Actions.isCurrentClassName(*Tok.getIdentifierInfo(), getCurScope()) &&
            isConstructorDeclarator(/*Unqualified*/true))
          goto DoneWithDeclSpec;
  
        ParsedType TypeRep = Actions.getTypeName(
            *Tok.getIdentifierInfo(), Tok.getLocation(), getCurScope(), nullptr,
            false, false, nullptr, false, false,
            isClassTemplateDeductionContext(DSContext));
  
        // If this is not a typedef name, don't parse it as part of the declspec,
        // it must be an implicit int or an error.
        if (!TypeRep) {
          CXXScopeSpec SS;
          if (TryAnnotateTypeConstraint(SS))
            continue;
          ParsedAttributesWithRange Attrs(AttrFactory);
          if (ParseImplicitInt(DS, nullptr, TemplateInfo, AS, DSContext, Attrs)) {
            if (!Attrs.empty()) {
              AttrsLastTime = true;
              attrs.takeAllFrom(Attrs);
            }
            continue;
          }
          goto DoneWithDeclSpec;
        }
  
        // Likewise, if this is a context where the identifier could be a template
        // name, check whether this is a deduction guide declaration.
        if (getLangOpts().CPlusPlus17 &&
            (DSContext == DeclSpecContext::DSC_class ||
             DSContext == DeclSpecContext::DSC_top_level) &&
            Actions.isDeductionGuideName(getCurScope(), *Tok.getIdentifierInfo(),
                                         Tok.getLocation()) &&
            isConstructorDeclarator(/*Unqualified*/ true,
                                    /*DeductionGuide*/ true))
          goto DoneWithDeclSpec;
  
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec,
                                       DiagID, TypeRep, Policy);
        if (isInvalid)
          break;
  
        DS.SetRangeEnd(Tok.getLocation());
        ConsumeToken(); // The identifier
  
        // Objective-C supports type arguments and protocol references
        // following an Objective-C object or object pointer
        // type. Handle either one of them.
        if (Tok.is(tok::less) && getLangOpts().ObjC) {
          SourceLocation NewEndLoc;
          TypeResult NewTypeRep = parseObjCTypeArgsAndProtocolQualifiers(
                                    Loc, TypeRep, /*consumeLastToken=*/true,
                                    NewEndLoc);
          if (NewTypeRep.isUsable()) {
            DS.UpdateTypeRep(NewTypeRep.get());
            DS.SetRangeEnd(NewEndLoc);
          }
        }
  
        // Need to support trailing type qualifiers (e.g. "id<p> const").
        // If a type specifier follows, it will be diagnosed elsewhere.
        continue;
      }
  
        // type-name or placeholder-specifier
      case tok::annot_template_id: {
        TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
        if (TemplateId->Kind == TNK_Concept_template) {
          if (NextToken().is(tok::identifier)) {
              Diag(Loc, diag::err_placeholder_missing_auto_after_type_constraint);
              // Attempt to continue as if 'auto' was placed here.
              isInvalid = DS.SetTypeSpecType(TST_auto, Loc, PrevSpec, DiagID,
                                             TemplateId, Policy);
              break;
          }
          if (!NextToken().isOneOf(tok::kw_auto, tok::kw_decltype))
              goto DoneWithDeclSpec;
          ConsumeAnnotationToken();
          SourceLocation AutoLoc = Tok.getLocation();
          if (TryConsumeToken(tok::kw_decltype)) {
            if (!Tok.is(tok::l_paren)) {
              // Something like `void foo(Iterator decltype i)`
              Diag(Tok, diag::err_expected) << tok::l_paren
                << FixItHint::CreateInsertion(Tok.getLocation(), "(auto)");
              UnconsumeToken(Tok);
            } else {
              ConsumeParen();
              if (!TryConsumeToken(tok::kw_auto)) {
                // Something like `void foo(Iterator decltype(int) i)`
                SkipUntil(tok::r_paren, SkipUntilFlags::StopBeforeMatch);
                Diag(Tok, diag::err_placeholder_decltype_non_auto)
                  << FixItHint::CreateReplacement(SourceRange(AutoLoc,
                                                              Tok.getLocation()),
                                                  "auto");
              } else if (Tok.isNot(tok::r_paren)) {
                Diag(Tok, diag::err_expected) << tok::r_paren
                  << FixItHint::CreateInsertion(Tok.getLocation(), ")");
              }
            }
            // Even if something went wrong above, continue as if we've seen
            // `decltype(auto)`.
            isInvalid = DS.SetTypeSpecType(TST_decltype_auto, Loc, PrevSpec,
                                           DiagID, TemplateId, Policy);
          } else {
            isInvalid = DS.SetTypeSpecType(TST_auto, Loc, PrevSpec, DiagID,
                                           TemplateId, Policy);
          }
          break;
        }
  
        if (TemplateId->Kind != TNK_Type_template &&
            TemplateId->Kind != TNK_Undeclared_template) {
          // This template-id does not refer to a type name, so we're
          // done with the type-specifiers.
          goto DoneWithDeclSpec;
        }
  
        // If we're in a context where the template-id could be a
        // constructor name or specialization, check whether this is a
        // constructor declaration.
        if (getLangOpts().CPlusPlus && DSContext == DeclSpecContext::DSC_class &&
            Actions.isCurrentClassName(*TemplateId->Name, getCurScope()) &&
            isConstructorDeclarator(TemplateId->SS.isEmpty()))
          goto DoneWithDeclSpec;
  
        // Turn the template-id annotation token into a type annotation
        // token, then try again to parse it as a type-specifier.
        AnnotateTemplateIdTokenAsType();
        continue;
      }
  
      // GNU attributes support.
      case tok::kw___attribute:
        ParseGNUAttributes(DS.getAttributes(), nullptr, LateAttrs);
        continue;
  
      // Microsoft declspec support.
      case tok::kw___declspec:
        ParseMicrosoftDeclSpecs(DS.getAttributes());
        continue;
  
      // Microsoft single token adornments.
      case tok::kw___forceinline: {
        isInvalid = DS.setFunctionSpecForceInline(Loc, PrevSpec, DiagID);
        IdentifierInfo *AttrName = Tok.getIdentifierInfo();
        SourceLocation AttrNameLoc = Tok.getLocation();
        DS.getAttributes().addNew(AttrName, AttrNameLoc, nullptr, AttrNameLoc,
                                  nullptr, 0, ParsedAttr::AS_Keyword);
        break;
      }
  
      case tok::kw___unaligned:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_unaligned, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
  
      case tok::kw___sptr:
      case tok::kw___uptr:
      case tok::kw___ptr64:
      case tok::kw___ptr32:
      case tok::kw___w64:
      case tok::kw___cdecl:
      case tok::kw___stdcall:
      case tok::kw___fastcall:
      case tok::kw___thiscall:
      case tok::kw___regcall:
      case tok::kw___vectorcall:
        ParseMicrosoftTypeAttributes(DS.getAttributes());
        continue;
  
      // Borland single token adornments.
      case tok::kw___pascal:
        ParseBorlandTypeAttributes(DS.getAttributes());
        continue;
  
      // OpenCL single token adornments.
      case tok::kw___kernel:
        ParseOpenCLKernelAttributes(DS.getAttributes());
        continue;
  
      // Nullability type specifiers.
      case tok::kw__Nonnull:
      case tok::kw__Nullable:
      case tok::kw__Null_unspecified:
        ParseNullabilityTypeSpecifiers(DS.getAttributes());
        continue;
  
      // Objective-C 'kindof' types.
      case tok::kw___kindof:
        DS.getAttributes().addNew(Tok.getIdentifierInfo(), Loc, nullptr, Loc,
                                  nullptr, 0, ParsedAttr::AS_Keyword);
        (void)ConsumeToken();
        continue;
  
      // storage-class-specifier
      case tok::kw_typedef:
        isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_typedef, Loc,
                                           PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw_extern:
        if (DS.getThreadStorageClassSpec() == DeclSpec::TSCS___thread)
          Diag(Tok, diag::ext_thread_before) << "extern";
        isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_extern, Loc,
                                           PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw___private_extern__:
        isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_private_extern,
                                           Loc, PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw_static:
        if (DS.getThreadStorageClassSpec() == DeclSpec::TSCS___thread)
          Diag(Tok, diag::ext_thread_before) << "static";
        isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_static, Loc,
                                           PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw_auto:
        if (getLangOpts().CPlusPlus11) {
          if (isKnownToBeTypeSpecifier(GetLookAheadToken(1))) {
            isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_auto, Loc,
                                               PrevSpec, DiagID, Policy);
            if (!isInvalid)
              Diag(Tok, diag::ext_auto_storage_class)
                << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
          } else
            isInvalid = DS.SetTypeSpecType(DeclSpec::TST_auto, Loc, PrevSpec,
                                           DiagID, Policy);
        } else
          isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_auto, Loc,
                                             PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw___auto_type:
        Diag(Tok, diag::ext_auto_type);
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_auto_type, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_register:
        isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_register, Loc,
                                           PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw_mutable:
        isInvalid = DS.SetStorageClassSpec(Actions, DeclSpec::SCS_mutable, Loc,
                                           PrevSpec, DiagID, Policy);
        isStorageClass = true;
        break;
      case tok::kw___thread:
        isInvalid = DS.SetStorageClassSpecThread(DeclSpec::TSCS___thread, Loc,
                                                 PrevSpec, DiagID);
        isStorageClass = true;
        break;
      case tok::kw_thread_local:
        isInvalid = DS.SetStorageClassSpecThread(DeclSpec::TSCS_thread_local, Loc,
                                                 PrevSpec, DiagID);
        isStorageClass = true;
        break;
      case tok::kw__Thread_local:
        isInvalid = DS.SetStorageClassSpecThread(DeclSpec::TSCS__Thread_local,
                                                 Loc, PrevSpec, DiagID);
        isStorageClass = true;
        break;
  
      // function-specifier
      case tok::kw_inline:
        isInvalid = DS.setFunctionSpecInline(Loc, PrevSpec, DiagID);
        break;
      case tok::kw_virtual:
        // OpenCL C++ v1.0 s2.9: the virtual function qualifier is not supported.
        if (getLangOpts().OpenCLCPlusPlus) {
          DiagID = diag::err_openclcxx_virtual_function;
          PrevSpec = Tok.getIdentifierInfo()->getNameStart();
          isInvalid = true;
        }
        else {
          isInvalid = DS.setFunctionSpecVirtual(Loc, PrevSpec, DiagID);
        }
        break;
      case tok::kw_explicit: {
        SourceLocation ExplicitLoc = Loc;
        SourceLocation CloseParenLoc;
        ExplicitSpecifier ExplicitSpec(nullptr, ExplicitSpecKind::ResolvedTrue);
        ConsumedEnd = ExplicitLoc;
        ConsumeToken(); // kw_explicit
        if (Tok.is(tok::l_paren)) {
          if (getLangOpts().CPlusPlus2a) {
            ExprResult ExplicitExpr(static_cast<Expr *>(nullptr));
            BalancedDelimiterTracker Tracker(*this, tok::l_paren);
            Tracker.consumeOpen();
            ExplicitExpr = ParseConstantExpression();
            ConsumedEnd = Tok.getLocation();
            if (ExplicitExpr.isUsable()) {
              CloseParenLoc = Tok.getLocation();
              Tracker.consumeClose();
              ExplicitSpec =
                  Actions.ActOnExplicitBoolSpecifier(ExplicitExpr.get());
            } else
              Tracker.skipToEnd();
          } else
            Diag(Tok.getLocation(), diag::warn_cxx2a_compat_explicit_bool);
        }
        isInvalid = DS.setFunctionSpecExplicit(ExplicitLoc, PrevSpec, DiagID,
                                               ExplicitSpec, CloseParenLoc);
        break;
      }
      case tok::kw__Noreturn:
        if (!getLangOpts().C11)
          Diag(Loc, diag::ext_c11_noreturn);
        isInvalid = DS.setFunctionSpecNoreturn(Loc, PrevSpec, DiagID);
        break;
  
      // alignment-specifier
      case tok::kw__Alignas:
        if (!getLangOpts().C11)
          Diag(Tok, diag::ext_c11_alignment) << Tok.getName();
        ParseAlignmentSpecifier(DS.getAttributes());
        continue;
  
      // friend
      case tok::kw_friend:
        if (DSContext == DeclSpecContext::DSC_class)
          isInvalid = DS.SetFriendSpec(Loc, PrevSpec, DiagID);
        else {
          PrevSpec = ""; // not actually used by the diagnostic
          DiagID = diag::err_friend_invalid_in_context;
          isInvalid = true;
        }
        break;
  
      // Modules
      case tok::kw___module_private__:
        isInvalid = DS.setModulePrivateSpec(Loc, PrevSpec, DiagID);
        break;
  
      // constexpr
      case tok::kw_constexpr:
        isInvalid = DS.SetConstexprSpec(CSK_constexpr, Loc, PrevSpec, DiagID);
        break;
  
      // consteval
      case tok::kw_consteval:
        isInvalid = DS.SetConstexprSpec(CSK_consteval, Loc, PrevSpec, DiagID);
        break;
  
      // type-specifier
      case tok::kw_short:
        isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_short, Loc, PrevSpec,
                                        DiagID, Policy);
        break;
      case tok::kw_long:
        if (DS.getTypeSpecWidth() != DeclSpec::TSW_long)
          isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_long, Loc, PrevSpec,
                                          DiagID, Policy);
        else
          isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_longlong, Loc, PrevSpec,
                                          DiagID, Policy);
        break;
      case tok::kw___int64:
          isInvalid = DS.SetTypeSpecWidth(DeclSpec::TSW_longlong, Loc, PrevSpec,
                                          DiagID, Policy);
        break;
      case tok::kw_signed:
        isInvalid = DS.SetTypeSpecSign(DeclSpec::TSS_signed, Loc, PrevSpec,
                                       DiagID);
        break;
      case tok::kw_unsigned:
        isInvalid = DS.SetTypeSpecSign(DeclSpec::TSS_unsigned, Loc, PrevSpec,
                                       DiagID);
        break;
      case tok::kw__Complex:
        isInvalid = DS.SetTypeSpecComplex(DeclSpec::TSC_complex, Loc, PrevSpec,
                                          DiagID);
        break;
      case tok::kw__Imaginary:
        isInvalid = DS.SetTypeSpecComplex(DeclSpec::TSC_imaginary, Loc, PrevSpec,
                                          DiagID);
        break;
      case tok::kw_void:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_void, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_char:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_int:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw___int128:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_int128, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_half:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_half, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_float:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_double:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw__Float16:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_float16, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw__Accum:
        if (!getLangOpts().FixedPoint) {
          SetupFixedPointError(getLangOpts(), PrevSpec, DiagID, isInvalid);
        } else {
          isInvalid = DS.SetTypeSpecType(DeclSpec::TST_accum, Loc, PrevSpec,
                                         DiagID, Policy);
        }
        break;
      case tok::kw__Fract:
        if (!getLangOpts().FixedPoint) {
          SetupFixedPointError(getLangOpts(), PrevSpec, DiagID, isInvalid);
        } else {
          isInvalid = DS.SetTypeSpecType(DeclSpec::TST_fract, Loc, PrevSpec,
                                         DiagID, Policy);
        }
        break;
      case tok::kw__Sat:
        if (!getLangOpts().FixedPoint) {
          SetupFixedPointError(getLangOpts(), PrevSpec, DiagID, isInvalid);
        } else {
          isInvalid = DS.SetTypeSpecSat(Loc, PrevSpec, DiagID);
        }
        break;
      case tok::kw___float128:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_float128, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_wchar_t:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_wchar, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_char8_t:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_char8, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_char16_t:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_char16, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_char32_t:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_char32, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw_bool:
      case tok::kw__Bool:
        if (Tok.is(tok::kw_bool) &&
            DS.getTypeSpecType() != DeclSpec::TST_unspecified &&
            DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
          PrevSpec = ""; // Not used by the diagnostic.
          DiagID = diag::err_bool_redeclaration;
          // For better error recovery.
          Tok.setKind(tok::identifier);
          isInvalid = true;
        } else {
          isInvalid = DS.SetTypeSpecType(DeclSpec::TST_bool, Loc, PrevSpec,
                                         DiagID, Policy);
        }
        break;
      case tok::kw__Decimal32:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_decimal32, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw__Decimal64:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_decimal64, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw__Decimal128:
        isInvalid = DS.SetTypeSpecType(DeclSpec::TST_decimal128, Loc, PrevSpec,
                                       DiagID, Policy);
        break;
      case tok::kw___vector:
        isInvalid = DS.SetTypeAltiVecVector(true, Loc, PrevSpec, DiagID, Policy);
        break;
      case tok::kw___pixel:
        isInvalid = DS.SetTypeAltiVecPixel(true, Loc, PrevSpec, DiagID, Policy);
        break;
      case tok::kw___bool:
        isInvalid = DS.SetTypeAltiVecBool(true, Loc, PrevSpec, DiagID, Policy);
        break;
      case tok::kw_pipe:
        if (!getLangOpts().OpenCL || (getLangOpts().OpenCLVersion < 200 &&
                                      !getLangOpts().OpenCLCPlusPlus)) {
          // OpenCL 2.0 defined this keyword. OpenCL 1.2 and earlier should
          // support the "pipe" word as identifier.
          Tok.getIdentifierInfo()->revertTokenIDToIdentifier();
          goto DoneWithDeclSpec;
        }
        isInvalid = DS.SetTypePipe(true, Loc, PrevSpec, DiagID, Policy);
        break;
  #define GENERIC_IMAGE_TYPE(ImgType, Id) \
    case tok::kw_##ImgType##_t: \
      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_##ImgType##_t, Loc, PrevSpec, \
                                     DiagID, Policy); \
      break;
  #include "clang/Basic/OpenCLImageTypes.def"
      case tok::kw___unknown_anytype:
        isInvalid = DS.SetTypeSpecType(TST_unknown_anytype, Loc,
                                       PrevSpec, DiagID, Policy);
        break;
  
      // class-specifier:
      case tok::kw_class:
      case tok::kw_struct:
      case tok::kw___interface:
      case tok::kw_union: {
        tok::TokenKind Kind = Tok.getKind();
        ConsumeToken();
  
        // These are attributes following class specifiers.
        // To produce better diagnostic, we parse them when
        // parsing class specifier.
        ParsedAttributesWithRange Attributes(AttrFactory);
        ParseClassSpecifier(Kind, Loc, DS, TemplateInfo, AS,
                            EnteringContext, DSContext, Attributes);
  
        // If there are attributes following class specifier,
        // take them over and handle them here.
        if (!Attributes.empty()) {
          AttrsLastTime = true;
          attrs.takeAllFrom(Attributes);
        }
        continue;
      }
  
      // enum-specifier:
      case tok::kw_enum:
        ConsumeToken();
        ParseEnumSpecifier(Loc, DS, TemplateInfo, AS, DSContext);
        continue;
  
      // cv-qualifier:
      case tok::kw_const:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_const, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
      case tok::kw_volatile:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_volatile, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
      case tok::kw_restrict:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_restrict, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
  
      // C++ typename-specifier:
      case tok::kw_typename:
        if (TryAnnotateTypeOrScopeToken()) {
          DS.SetTypeSpecError();
          goto DoneWithDeclSpec;
        }
        if (!Tok.is(tok::kw_typename))
          continue;
        break;
  
      // GNU typeof support.
      case tok::kw_typeof:
        ParseTypeofSpecifier(DS);
        continue;
  
      case tok::annot_decltype:
        ParseDecltypeSpecifier(DS);
        continue;
  
      case tok::annot_pragma_pack:
        HandlePragmaPack();
        continue;
  
      case tok::annot_pragma_ms_pragma:
        HandlePragmaMSPragma();
        continue;
  
      case tok::annot_pragma_ms_vtordisp:
        HandlePragmaMSVtorDisp();
        continue;
  
      case tok::annot_pragma_ms_pointers_to_members:
        HandlePragmaMSPointersToMembers();
        continue;
  
      case tok::kw___underlying_type:
        ParseUnderlyingTypeSpecifier(DS);
        continue;
  
      case tok::kw__Atomic:
        // C11 6.7.2.4/4:
        //   If the _Atomic keyword is immediately followed by a left parenthesis,
        //   it is interpreted as a type specifier (with a type name), not as a
        //   type qualifier.
        if (NextToken().is(tok::l_paren)) {
          ParseAtomicSpecifier(DS);
          continue;
        }
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_atomic, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
  
      // OpenCL address space qualifiers:
      case tok::kw___generic:
        // generic address space is introduced only in OpenCL v2.0
        // see OpenCL C Spec v2.0 s6.5.5
        if (Actions.getLangOpts().OpenCLVersion < 200 &&
            !Actions.getLangOpts().OpenCLCPlusPlus) {
          DiagID = diag::err_opencl_unknown_type_specifier;
          PrevSpec = Tok.getIdentifierInfo()->getNameStart();
          isInvalid = true;
          break;
        };
        LLVM_FALLTHROUGH;
      case tok::kw_private:
      case tok::kw___private:
      case tok::kw___global:
      case tok::kw___local:
      case tok::kw___constant:
      // OpenCL access qualifiers:
      case tok::kw___read_only:
      case tok::kw___write_only:
      case tok::kw___read_write:
        ParseOpenCLQualifiers(DS.getAttributes());
        break;
  
      case tok::less:
        // GCC ObjC supports types like "<SomeProtocol>" as a synonym for
        // "id<SomeProtocol>".  This is hopelessly old fashioned and dangerous,
        // but we support it.
        if (DS.hasTypeSpecifier() || !getLangOpts().ObjC)
          goto DoneWithDeclSpec;
  
        SourceLocation StartLoc = Tok.getLocation();
        SourceLocation EndLoc;
        TypeResult Type = parseObjCProtocolQualifierType(EndLoc);
        if (Type.isUsable()) {
          if (DS.SetTypeSpecType(DeclSpec::TST_typename, StartLoc, StartLoc,
                                 PrevSpec, DiagID, Type.get(),
                                 Actions.getASTContext().getPrintingPolicy()))
            Diag(StartLoc, DiagID) << PrevSpec;
  
          DS.SetRangeEnd(EndLoc);
        } else {
          DS.SetTypeSpecError();
        }
  
        // Need to support trailing type qualifiers (e.g. "id<p> const").
        // If a type specifier follows, it will be diagnosed elsewhere.
        continue;
      }
  
      DS.SetRangeEnd(ConsumedEnd.isValid() ? ConsumedEnd : Tok.getLocation());
  
      // If the specifier wasn't legal, issue a diagnostic.
      if (isInvalid) {
        assert(PrevSpec && "Method did not return previous specifier!");
        assert(DiagID);
  
        if (DiagID == diag::ext_duplicate_declspec ||
            DiagID == diag::ext_warn_duplicate_declspec ||
            DiagID == diag::err_duplicate_declspec)
          Diag(Loc, DiagID) << PrevSpec
                            << FixItHint::CreateRemoval(
                                   SourceRange(Loc, DS.getEndLoc()));
        else if (DiagID == diag::err_opencl_unknown_type_specifier) {
          Diag(Loc, DiagID) << getLangOpts().OpenCLCPlusPlus
                            << getLangOpts().getOpenCLVersionTuple().getAsString()
                            << PrevSpec << isStorageClass;
        } else
          Diag(Loc, DiagID) << PrevSpec;
      }
  
      if (DiagID != diag::err_bool_redeclaration && ConsumedEnd.isInvalid())
        // After an error the next token can be an annotation token.
        ConsumeAnyToken();
  
      AttrsLastTime = false;
    }
  }
  
  /// ParseStructDeclaration - Parse a struct declaration without the terminating
  /// semicolon.
  ///
  /// Note that a struct declaration refers to a declaration in a struct,
  /// not to the declaration of a struct.
  ///
  ///       struct-declaration:
  /// [C2x]   attributes-specifier-seq[opt]
  ///           specifier-qualifier-list struct-declarator-list
  /// [GNU]   __extension__ struct-declaration
  /// [GNU]   specifier-qualifier-list
  ///       struct-declarator-list:
  ///         struct-declarator
  ///         struct-declarator-list ',' struct-declarator
  /// [GNU]   struct-declarator-list ',' attributes[opt] struct-declarator
  ///       struct-declarator:
  ///         declarator
  /// [GNU]   declarator attributes[opt]
  ///         declarator[opt] ':' constant-expression
  /// [GNU]   declarator[opt] ':' constant-expression attributes[opt]
  ///
  void Parser::ParseStructDeclaration(
      ParsingDeclSpec &DS,
      llvm::function_ref<void(ParsingFieldDeclarator &)> FieldsCallback) {
  
    if (Tok.is(tok::kw___extension__)) {
      // __extension__ silences extension warnings in the subexpression.
      ExtensionRAIIObject O(Diags);  // Use RAII to do this.
      ConsumeToken();
      return ParseStructDeclaration(DS, FieldsCallback);
    }
  
    // Parse leading attributes.
    ParsedAttributesWithRange Attrs(AttrFactory);
    MaybeParseCXX11Attributes(Attrs);
    DS.takeAttributesFrom(Attrs);
  
    // Parse the common specifier-qualifiers-list piece.
    ParseSpecifierQualifierList(DS);
  
    // If there are no declarators, this is a free-standing declaration
    // specifier. Let the actions module cope with it.
    if (Tok.is(tok::semi)) {
      RecordDecl *AnonRecord = nullptr;
      Decl *TheDecl = Actions.ParsedFreeStandingDeclSpec(getCurScope(), AS_none,
                                                         DS, AnonRecord);
      assert(!AnonRecord && "Did not expect anonymous struct or union here");
      DS.complete(TheDecl);
      return;
    }
  
    // Read struct-declarators until we find the semicolon.
    bool FirstDeclarator = true;
    SourceLocation CommaLoc;
    while (1) {
      ParsingFieldDeclarator DeclaratorInfo(*this, DS);
      DeclaratorInfo.D.setCommaLoc(CommaLoc);
  
      // Attributes are only allowed here on successive declarators.
      if (!FirstDeclarator)
        MaybeParseGNUAttributes(DeclaratorInfo.D);
  
      /// struct-declarator: declarator
      /// struct-declarator: declarator[opt] ':' constant-expression
      if (Tok.isNot(tok::colon)) {
        // Don't parse FOO:BAR as if it were a typo for FOO::BAR.
        ColonProtectionRAIIObject X(*this);
        ParseDeclarator(DeclaratorInfo.D);
      } else
        DeclaratorInfo.D.SetIdentifier(nullptr, Tok.getLocation());
  
      if (TryConsumeToken(tok::colon)) {
        ExprResult Res(ParseConstantExpression());
        if (Res.isInvalid())
          SkipUntil(tok::semi, StopBeforeMatch);
        else
          DeclaratorInfo.BitfieldSize = Res.get();
      }
  
      // If attributes exist after the declarator, parse them.
      MaybeParseGNUAttributes(DeclaratorInfo.D);
  
      // We're done with this declarator;  invoke the callback.
      FieldsCallback(DeclaratorInfo);
  
      // If we don't have a comma, it is either the end of the list (a ';')
      // or an error, bail out.
      if (!TryConsumeToken(tok::comma, CommaLoc))
        return;
  
      FirstDeclarator = false;
    }
  }
  
  /// ParseStructUnionBody
  ///       struct-contents:
  ///         struct-declaration-list
  /// [EXT]   empty
  /// [GNU]   "struct-declaration-list" without terminatoring ';'
  ///       struct-declaration-list:
  ///         struct-declaration
  ///         struct-declaration-list struct-declaration
  /// [OBC]   '@' 'defs' '(' class-name ')'
  ///
  void Parser::ParseStructUnionBody(SourceLocation RecordLoc,
                                    unsigned TagType, Decl *TagDecl) {
    PrettyDeclStackTraceEntry CrashInfo(Actions.Context, TagDecl, RecordLoc,
                                        "parsing struct/union body");
    assert(!getLangOpts().CPlusPlus && "C++ declarations not supported");
  
    BalancedDelimiterTracker T(*this, tok::l_brace);
    if (T.consumeOpen())
      return;
  
    ParseScope StructScope(this, Scope::ClassScope|Scope::DeclScope);
    Actions.ActOnTagStartDefinition(getCurScope(), TagDecl);
  
    SmallVector<Decl *, 32> FieldDecls;
  
    // While we still have something to read, read the declarations in the struct.
    while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
           Tok.isNot(tok::eof)) {
      // Each iteration of this loop reads one struct-declaration.
  
      // Check for extraneous top-level semicolon.
      if (Tok.is(tok::semi)) {
        ConsumeExtraSemi(InsideStruct, TagType);
        continue;
      }
  
      // Parse _Static_assert declaration.
      if (Tok.is(tok::kw__Static_assert)) {
        SourceLocation DeclEnd;
        ParseStaticAssertDeclaration(DeclEnd);
        continue;
      }
  
      if (Tok.is(tok::annot_pragma_pack)) {
        HandlePragmaPack();
        continue;
      }
  
      if (Tok.is(tok::annot_pragma_align)) {
        HandlePragmaAlign();
        continue;
      }
  
      if (Tok.is(tok::annot_pragma_openmp)) {
        // Result can be ignored, because it must be always empty.
        AccessSpecifier AS = AS_none;
        ParsedAttributesWithRange Attrs(AttrFactory);
        (void)ParseOpenMPDeclarativeDirectiveWithExtDecl(AS, Attrs);
        continue;
      }
  
      if (!Tok.is(tok::at)) {
        auto CFieldCallback = [&](ParsingFieldDeclarator &FD) {
          // Install the declarator into the current TagDecl.
          Decl *Field =
              Actions.ActOnField(getCurScope(), TagDecl,
                                 FD.D.getDeclSpec().getSourceRange().getBegin(),
                                 FD.D, FD.BitfieldSize);
          FieldDecls.push_back(Field);
          FD.complete(Field);
        };
  
        // Parse all the comma separated declarators.
        ParsingDeclSpec DS(*this);
        ParseStructDeclaration(DS, CFieldCallback);
      } else { // Handle @defs
        ConsumeToken();
        if (!Tok.isObjCAtKeyword(tok::objc_defs)) {
          Diag(Tok, diag::err_unexpected_at);
          SkipUntil(tok::semi);
          continue;
        }
        ConsumeToken();
        ExpectAndConsume(tok::l_paren);
        if (!Tok.is(tok::identifier)) {
          Diag(Tok, diag::err_expected) << tok::identifier;
          SkipUntil(tok::semi);
          continue;
        }
        SmallVector<Decl *, 16> Fields;
        Actions.ActOnDefs(getCurScope(), TagDecl, Tok.getLocation(),
                          Tok.getIdentifierInfo(), Fields);
        FieldDecls.insert(FieldDecls.end(), Fields.begin(), Fields.end());
        ConsumeToken();
        ExpectAndConsume(tok::r_paren);
      }
  
      if (TryConsumeToken(tok::semi))
        continue;
  
      if (Tok.is(tok::r_brace)) {
        ExpectAndConsume(tok::semi, diag::ext_expected_semi_decl_list);
        break;
      }
  
      ExpectAndConsume(tok::semi, diag::err_expected_semi_decl_list);
      // Skip to end of block or statement to avoid ext-warning on extra ';'.
      SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
      // If we stopped at a ';', eat it.
      TryConsumeToken(tok::semi);
    }
  
    T.consumeClose();
  
    ParsedAttributes attrs(AttrFactory);
    // If attributes exist after struct contents, parse them.
    MaybeParseGNUAttributes(attrs);
  
    Actions.ActOnFields(getCurScope(), RecordLoc, TagDecl, FieldDecls,
                        T.getOpenLocation(), T.getCloseLocation(), attrs);
    StructScope.Exit();
    Actions.ActOnTagFinishDefinition(getCurScope(), TagDecl, T.getRange());
  }
  
  /// ParseEnumSpecifier
  ///       enum-specifier: [C99 6.7.2.2]
  ///         'enum' identifier[opt] '{' enumerator-list '}'
  ///[C99/C++]'enum' identifier[opt] '{' enumerator-list ',' '}'
  /// [GNU]   'enum' attributes[opt] identifier[opt] '{' enumerator-list ',' [opt]
  ///                                                 '}' attributes[opt]
  /// [MS]    'enum' __declspec[opt] identifier[opt] '{' enumerator-list ',' [opt]
  ///                                                 '}'
  ///         'enum' identifier
  /// [GNU]   'enum' attributes[opt] identifier
  ///
  /// [C++11] enum-head '{' enumerator-list[opt] '}'
  /// [C++11] enum-head '{' enumerator-list ','  '}'
  ///
  ///       enum-head: [C++11]
  ///         enum-key attribute-specifier-seq[opt] identifier[opt] enum-base[opt]
  ///         enum-key attribute-specifier-seq[opt] nested-name-specifier
  ///             identifier enum-base[opt]
  ///
  ///       enum-key: [C++11]
  ///         'enum'
  ///         'enum' 'class'
  ///         'enum' 'struct'
  ///
  ///       enum-base: [C++11]
  ///         ':' type-specifier-seq
  ///
  /// [C++] elaborated-type-specifier:
  /// [C++]   'enum' '::'[opt] nested-name-specifier[opt] identifier
  ///
  void Parser::ParseEnumSpecifier(SourceLocation StartLoc, DeclSpec &DS,
                                  const ParsedTemplateInfo &TemplateInfo,
                                  AccessSpecifier AS, DeclSpecContext DSC) {
    // Parse the tag portion of this.
    if (Tok.is(tok::code_completion)) {
      // Code completion for an enum name.
      Actions.CodeCompleteTag(getCurScope(), DeclSpec::TST_enum);
      return cutOffParsing();
    }
  
    // If attributes exist after tag, parse them.
    ParsedAttributesWithRange attrs(AttrFactory);
    MaybeParseGNUAttributes(attrs);
    MaybeParseCXX11Attributes(attrs);
    MaybeParseMicrosoftDeclSpecs(attrs);
  
    SourceLocation ScopedEnumKWLoc;
    bool IsScopedUsingClassTag = false;
  
    // In C++11, recognize 'enum class' and 'enum struct'.
    if (Tok.isOneOf(tok::kw_class, tok::kw_struct)) {
      Diag(Tok, getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_scoped_enum
                                          : diag::ext_scoped_enum);
      IsScopedUsingClassTag = Tok.is(tok::kw_class);
      ScopedEnumKWLoc = ConsumeToken();
  
      // Attributes are not allowed between these keywords.  Diagnose,
      // but then just treat them like they appeared in the right place.
      ProhibitAttributes(attrs);
  
      // They are allowed afterwards, though.
      MaybeParseGNUAttributes(attrs);
      MaybeParseCXX11Attributes(attrs);
      MaybeParseMicrosoftDeclSpecs(attrs);
    }
  
    // C++11 [temp.explicit]p12:
    //   The usual access controls do not apply to names used to specify
    //   explicit instantiations.
    // We extend this to also cover explicit specializations.  Note that
    // we don't suppress if this turns out to be an elaborated type
    // specifier.
    bool shouldDelayDiagsInTag =
      (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation ||
       TemplateInfo.Kind == ParsedTemplateInfo::ExplicitSpecialization);
    SuppressAccessChecks diagsFromTag(*this, shouldDelayDiagsInTag);
  
    // Enum definitions should not be parsed in a trailing-return-type.
    bool AllowDeclaration = DSC != DeclSpecContext::DSC_trailing;
  
    CXXScopeSpec &SS = DS.getTypeSpecScope();
    if (getLangOpts().CPlusPlus) {
      // "enum foo : bar;" is not a potential typo for "enum foo::bar;"
      // if a fixed underlying type is allowed.
      ColonProtectionRAIIObject X(*this, AllowDeclaration);
  
      CXXScopeSpec Spec;
      if (ParseOptionalCXXScopeSpecifier(Spec, nullptr,
                                         /*EnteringContext=*/true))
        return;
  
      if (Spec.isSet() && Tok.isNot(tok::identifier)) {
        Diag(Tok, diag::err_expected) << tok::identifier;
        if (Tok.isNot(tok::l_brace)) {
          // Has no name and is not a definition.
          // Skip the rest of this declarator, up until the comma or semicolon.
          SkipUntil(tok::comma, StopAtSemi);
          return;
        }
      }
  
      SS = Spec;
    }
  
    // Must have either 'enum name' or 'enum {...}'.
    if (Tok.isNot(tok::identifier) && Tok.isNot(tok::l_brace) &&
        !(AllowDeclaration && Tok.is(tok::colon))) {
      Diag(Tok, diag::err_expected_either) << tok::identifier << tok::l_brace;
  
      // Skip the rest of this declarator, up until the comma or semicolon.
      SkipUntil(tok::comma, StopAtSemi);
      return;
    }
  
    // If an identifier is present, consume and remember it.
    IdentifierInfo *Name = nullptr;
    SourceLocation NameLoc;
    if (Tok.is(tok::identifier)) {
      Name = Tok.getIdentifierInfo();
      NameLoc = ConsumeToken();
    }
  
    if (!Name && ScopedEnumKWLoc.isValid()) {
      // C++0x 7.2p2: The optional identifier shall not be omitted in the
      // declaration of a scoped enumeration.
      Diag(Tok, diag::err_scoped_enum_missing_identifier);
      ScopedEnumKWLoc = SourceLocation();
      IsScopedUsingClassTag = false;
    }
  
    // Okay, end the suppression area.  We'll decide whether to emit the
    // diagnostics in a second.
    if (shouldDelayDiagsInTag)
      diagsFromTag.done();
  
    TypeResult BaseType;
  
    // Parse the fixed underlying type.
    bool CanBeBitfield = getCurScope()->getFlags() & Scope::ClassScope;
    if (AllowDeclaration && Tok.is(tok::colon)) {
      bool PossibleBitfield = false;
      if (CanBeBitfield) {
        // If we're in class scope, this can either be an enum declaration with
        // an underlying type, or a declaration of a bitfield member. We try to
        // use a simple disambiguation scheme first to catch the common cases
        // (integer literal, sizeof); if it's still ambiguous, we then consider
        // anything that's a simple-type-specifier followed by '(' as an
        // expression. This suffices because function types are not valid
        // underlying types anyway.
        EnterExpressionEvaluationContext Unevaluated(
            Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
        TPResult TPR = isExpressionOrTypeSpecifierSimple(NextToken().getKind());
        // If the next token starts an expression, we know we're parsing a
        // bit-field. This is the common case.
        if (TPR == TPResult::True)
          PossibleBitfield = true;
        // If the next token starts a type-specifier-seq, it may be either a
        // a fixed underlying type or the start of a function-style cast in C++;
        // lookahead one more token to see if it's obvious that we have a
        // fixed underlying type.
        else if (TPR == TPResult::False &&
                 GetLookAheadToken(2).getKind() == tok::semi) {
          // Consume the ':'.
          ConsumeToken();
        } else {
          // We have the start of a type-specifier-seq, so we have to perform
          // tentative parsing to determine whether we have an expression or a
          // type.
          TentativeParsingAction TPA(*this);
  
          // Consume the ':'.
          ConsumeToken();
  
          // If we see a type specifier followed by an open-brace, we have an
          // ambiguity between an underlying type and a C++11 braced
          // function-style cast. Resolve this by always treating it as an
          // underlying type.
          // FIXME: The standard is not entirely clear on how to disambiguate in
          // this case.
          if ((getLangOpts().CPlusPlus &&
               isCXXDeclarationSpecifier(TPResult::True) != TPResult::True) ||
              (!getLangOpts().CPlusPlus && !isDeclarationSpecifier(true))) {
            // We'll parse this as a bitfield later.
            PossibleBitfield = true;
            TPA.Revert();
          } else {
            // We have a type-specifier-seq.
            TPA.Commit();
          }
        }
      } else {
        // Consume the ':'.
        ConsumeToken();
      }
  
      if (!PossibleBitfield) {
        SourceRange Range;
        BaseType = ParseTypeName(&Range);
  
        if (!getLangOpts().ObjC) {
          if (getLangOpts().CPlusPlus11)
            Diag(StartLoc, diag::warn_cxx98_compat_enum_fixed_underlying_type);
          else if (getLangOpts().CPlusPlus)
            Diag(StartLoc, diag::ext_cxx11_enum_fixed_underlying_type);
          else if (getLangOpts().MicrosoftExt)
            Diag(StartLoc, diag::ext_ms_c_enum_fixed_underlying_type);
          else
            Diag(StartLoc, diag::ext_clang_c_enum_fixed_underlying_type);
        }
      }
    }
  
    // There are four options here.  If we have 'friend enum foo;' then this is a
    // friend declaration, and cannot have an accompanying definition. If we have
    // 'enum foo;', then this is a forward declaration.  If we have
    // 'enum foo {...' then this is a definition. Otherwise we have something
    // like 'enum foo xyz', a reference.
    //
    // This is needed to handle stuff like this right (C99 6.7.2.3p11):
    // enum foo {..};  void bar() { enum foo; }    <- new foo in bar.
    // enum foo {..};  void bar() { enum foo x; }  <- use of old foo.
    //
    Sema::TagUseKind TUK;
    if (!AllowDeclaration) {
      TUK = Sema::TUK_Reference;
    } else if (Tok.is(tok::l_brace)) {
      if (DS.isFriendSpecified()) {
        Diag(Tok.getLocation(), diag::err_friend_decl_defines_type)
          << SourceRange(DS.getFriendSpecLoc());
        ConsumeBrace();
        SkipUntil(tok::r_brace, StopAtSemi);
        TUK = Sema::TUK_Friend;
      } else {
        TUK = Sema::TUK_Definition;
      }
    } else if (!isTypeSpecifier(DSC) &&
               (Tok.is(tok::semi) ||
                (Tok.isAtStartOfLine() &&
                 !isValidAfterTypeSpecifier(CanBeBitfield)))) {
      TUK = DS.isFriendSpecified() ? Sema::TUK_Friend : Sema::TUK_Declaration;
      if (Tok.isNot(tok::semi)) {
        // A semicolon was missing after this declaration. Diagnose and recover.
        ExpectAndConsume(tok::semi, diag::err_expected_after, "enum");
        PP.EnterToken(Tok, /*IsReinject=*/true);
        Tok.setKind(tok::semi);
      }
    } else {
      TUK = Sema::TUK_Reference;
    }
  
    // If this is an elaborated type specifier, and we delayed
    // diagnostics before, just merge them into the current pool.
    if (TUK == Sema::TUK_Reference && shouldDelayDiagsInTag) {
      diagsFromTag.redelay();
    }
  
    MultiTemplateParamsArg TParams;
    if (TemplateInfo.Kind != ParsedTemplateInfo::NonTemplate &&
        TUK != Sema::TUK_Reference) {
      if (!getLangOpts().CPlusPlus11 || !SS.isSet()) {
        // Skip the rest of this declarator, up until the comma or semicolon.
        Diag(Tok, diag::err_enum_template);
        SkipUntil(tok::comma, StopAtSemi);
        return;
      }
  
      if (TemplateInfo.Kind == ParsedTemplateInfo::ExplicitInstantiation) {
        // Enumerations can't be explicitly instantiated.
        DS.SetTypeSpecError();
        Diag(StartLoc, diag::err_explicit_instantiation_enum);
        return;
      }
  
      assert(TemplateInfo.TemplateParams && "no template parameters");
      TParams = MultiTemplateParamsArg(TemplateInfo.TemplateParams->data(),
                                       TemplateInfo.TemplateParams->size());
    }
  
    if (TUK == Sema::TUK_Reference)
      ProhibitAttributes(attrs);
  
    if (!Name && TUK != Sema::TUK_Definition) {
      Diag(Tok, diag::err_enumerator_unnamed_no_def);
  
      // Skip the rest of this declarator, up until the comma or semicolon.
      SkipUntil(tok::comma, StopAtSemi);
      return;
    }
  
    stripTypeAttributesOffDeclSpec(attrs, DS, TUK);
  
    Sema::SkipBodyInfo SkipBody;
    if (!Name && TUK == Sema::TUK_Definition && Tok.is(tok::l_brace) &&
        NextToken().is(tok::identifier))
      SkipBody = Actions.shouldSkipAnonEnumBody(getCurScope(),
                                                NextToken().getIdentifierInfo(),
                                                NextToken().getLocation());
  
    bool Owned = false;
    bool IsDependent = false;
    const char *PrevSpec = nullptr;
    unsigned DiagID;
    Decl *TagDecl = Actions.ActOnTag(
        getCurScope(), DeclSpec::TST_enum, TUK, StartLoc, SS, Name, NameLoc,
        attrs, AS, DS.getModulePrivateSpecLoc(), TParams, Owned, IsDependent,
        ScopedEnumKWLoc, IsScopedUsingClassTag, BaseType,
        DSC == DeclSpecContext::DSC_type_specifier,
        DSC == DeclSpecContext::DSC_template_param ||
            DSC == DeclSpecContext::DSC_template_type_arg,
        &SkipBody);
  
    if (SkipBody.ShouldSkip) {
      assert(TUK == Sema::TUK_Definition && "can only skip a definition");
  
      BalancedDelimiterTracker T(*this, tok::l_brace);
      T.consumeOpen();
      T.skipToEnd();
  
      if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc,
                             NameLoc.isValid() ? NameLoc : StartLoc,
                             PrevSpec, DiagID, TagDecl, Owned,
                             Actions.getASTContext().getPrintingPolicy()))
        Diag(StartLoc, DiagID) << PrevSpec;
      return;
    }
  
    if (IsDependent) {
      // This enum has a dependent nested-name-specifier. Handle it as a
      // dependent tag.
      if (!Name) {
        DS.SetTypeSpecError();
        Diag(Tok, diag::err_expected_type_name_after_typename);
        return;
      }
  
      TypeResult Type = Actions.ActOnDependentTag(
          getCurScope(), DeclSpec::TST_enum, TUK, SS, Name, StartLoc, NameLoc);
      if (Type.isInvalid()) {
        DS.SetTypeSpecError();
        return;
      }
  
      if (DS.SetTypeSpecType(DeclSpec::TST_typename, StartLoc,
                             NameLoc.isValid() ? NameLoc : StartLoc,
                             PrevSpec, DiagID, Type.get(),
                             Actions.getASTContext().getPrintingPolicy()))
        Diag(StartLoc, DiagID) << PrevSpec;
  
      return;
    }
  
    if (!TagDecl) {
      // The action failed to produce an enumeration tag. If this is a
      // definition, consume the entire definition.
      if (Tok.is(tok::l_brace) && TUK != Sema::TUK_Reference) {
        ConsumeBrace();
        SkipUntil(tok::r_brace, StopAtSemi);
      }
  
      DS.SetTypeSpecError();
      return;
    }
  
    if (Tok.is(tok::l_brace) && TUK != Sema::TUK_Reference) {
      Decl *D = SkipBody.CheckSameAsPrevious ? SkipBody.New : TagDecl;
      ParseEnumBody(StartLoc, D);
      if (SkipBody.CheckSameAsPrevious &&
          !Actions.ActOnDuplicateDefinition(DS, TagDecl, SkipBody)) {
        DS.SetTypeSpecError();
        return;
      }
    }
  
    if (DS.SetTypeSpecType(DeclSpec::TST_enum, StartLoc,
                           NameLoc.isValid() ? NameLoc : StartLoc,
                           PrevSpec, DiagID, TagDecl, Owned,
                           Actions.getASTContext().getPrintingPolicy()))
      Diag(StartLoc, DiagID) << PrevSpec;
  }
  
  /// ParseEnumBody - Parse a {} enclosed enumerator-list.
  ///       enumerator-list:
  ///         enumerator
  ///         enumerator-list ',' enumerator
  ///       enumerator:
  ///         enumeration-constant attributes[opt]
  ///         enumeration-constant attributes[opt] '=' constant-expression
  ///       enumeration-constant:
  ///         identifier
  ///
  void Parser::ParseEnumBody(SourceLocation StartLoc, Decl *EnumDecl) {
    // Enter the scope of the enum body and start the definition.
    ParseScope EnumScope(this, Scope::DeclScope | Scope::EnumScope);
    Actions.ActOnTagStartDefinition(getCurScope(), EnumDecl);
  
    BalancedDelimiterTracker T(*this, tok::l_brace);
    T.consumeOpen();
  
    // C does not allow an empty enumerator-list, C++ does [dcl.enum].
    if (Tok.is(tok::r_brace) && !getLangOpts().CPlusPlus)
      Diag(Tok, diag::err_empty_enum);
  
    SmallVector<Decl *, 32> EnumConstantDecls;
    SmallVector<SuppressAccessChecks, 32> EnumAvailabilityDiags;
  
    Decl *LastEnumConstDecl = nullptr;
  
    // Parse the enumerator-list.
    while (Tok.isNot(tok::r_brace)) {
      // Parse enumerator. If failed, try skipping till the start of the next
      // enumerator definition.
      if (Tok.isNot(tok::identifier)) {
        Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
        if (SkipUntil(tok::comma, tok::r_brace, StopBeforeMatch) &&
            TryConsumeToken(tok::comma))
          continue;
        break;
      }
      IdentifierInfo *Ident = Tok.getIdentifierInfo();
      SourceLocation IdentLoc = ConsumeToken();
  
      // If attributes exist after the enumerator, parse them.
      ParsedAttributesWithRange attrs(AttrFactory);
      MaybeParseGNUAttributes(attrs);
      ProhibitAttributes(attrs); // GNU-style attributes are prohibited.
      if (standardAttributesAllowed() && isCXX11AttributeSpecifier()) {
        if (getLangOpts().CPlusPlus)
          Diag(Tok.getLocation(), getLangOpts().CPlusPlus17
                                      ? diag::warn_cxx14_compat_ns_enum_attribute
                                      : diag::ext_ns_enum_attribute)
              << 1 /*enumerator*/;
        ParseCXX11Attributes(attrs);
      }
  
      SourceLocation EqualLoc;
      ExprResult AssignedVal;
      EnumAvailabilityDiags.emplace_back(*this);
  
      if (TryConsumeToken(tok::equal, EqualLoc)) {
        AssignedVal = ParseConstantExpression();
        if (AssignedVal.isInvalid())
          SkipUntil(tok::comma, tok::r_brace, StopBeforeMatch);
      }
  
      // Install the enumerator constant into EnumDecl.
      Decl *EnumConstDecl = Actions.ActOnEnumConstant(
          getCurScope(), EnumDecl, LastEnumConstDecl, IdentLoc, Ident, attrs,
          EqualLoc, AssignedVal.get());
      EnumAvailabilityDiags.back().done();
  
      EnumConstantDecls.push_back(EnumConstDecl);
      LastEnumConstDecl = EnumConstDecl;
  
      if (Tok.is(tok::identifier)) {
        // We're missing a comma between enumerators.
        SourceLocation Loc = getEndOfPreviousToken();
        Diag(Loc, diag::err_enumerator_list_missing_comma)
          << FixItHint::CreateInsertion(Loc, ", ");
        continue;
      }
  
      // Emumerator definition must be finished, only comma or r_brace are
      // allowed here.
      SourceLocation CommaLoc;
      if (Tok.isNot(tok::r_brace) && !TryConsumeToken(tok::comma, CommaLoc)) {
        if (EqualLoc.isValid())
          Diag(Tok.getLocation(), diag::err_expected_either) << tok::r_brace
                                                             << tok::comma;
        else
          Diag(Tok.getLocation(), diag::err_expected_end_of_enumerator);
        if (SkipUntil(tok::comma, tok::r_brace, StopBeforeMatch)) {
          if (TryConsumeToken(tok::comma, CommaLoc))
            continue;
        } else {
          break;
        }
      }
  
      // If comma is followed by r_brace, emit appropriate warning.
      if (Tok.is(tok::r_brace) && CommaLoc.isValid()) {
        if (!getLangOpts().C99 && !getLangOpts().CPlusPlus11)
          Diag(CommaLoc, getLangOpts().CPlusPlus ?
                 diag::ext_enumerator_list_comma_cxx :
                 diag::ext_enumerator_list_comma_c)
            << FixItHint::CreateRemoval(CommaLoc);
        else if (getLangOpts().CPlusPlus11)
          Diag(CommaLoc, diag::warn_cxx98_compat_enumerator_list_comma)
            << FixItHint::CreateRemoval(CommaLoc);
        break;
      }
    }
  
    // Eat the }.
    T.consumeClose();
  
    // If attributes exist after the identifier list, parse them.
    ParsedAttributes attrs(AttrFactory);
    MaybeParseGNUAttributes(attrs);
  
    Actions.ActOnEnumBody(StartLoc, T.getRange(), EnumDecl, EnumConstantDecls,
                          getCurScope(), attrs);
  
    // Now handle enum constant availability diagnostics.
    assert(EnumConstantDecls.size() == EnumAvailabilityDiags.size());
    for (size_t i = 0, e = EnumConstantDecls.size(); i != e; ++i) {
      ParsingDeclRAIIObject PD(*this, ParsingDeclRAIIObject::NoParent);
      EnumAvailabilityDiags[i].redelay();
      PD.complete(EnumConstantDecls[i]);
    }
  
    EnumScope.Exit();
    Actions.ActOnTagFinishDefinition(getCurScope(), EnumDecl, T.getRange());
  
    // The next token must be valid after an enum definition. If not, a ';'
    // was probably forgotten.
    bool CanBeBitfield = getCurScope()->getFlags() & Scope::ClassScope;
    if (!isValidAfterTypeSpecifier(CanBeBitfield)) {
      ExpectAndConsume(tok::semi, diag::err_expected_after, "enum");
      // Push this token back into the preprocessor and change our current token
      // to ';' so that the rest of the code recovers as though there were an
      // ';' after the definition.
      PP.EnterToken(Tok, /*IsReinject=*/true);
      Tok.setKind(tok::semi);
    }
  }
  
  /// isKnownToBeTypeSpecifier - Return true if we know that the specified token
  /// is definitely a type-specifier.  Return false if it isn't part of a type
  /// specifier or if we're not sure.
  bool Parser::isKnownToBeTypeSpecifier(const Token &Tok) const {
    switch (Tok.getKind()) {
    default: return false;
      // type-specifiers
    case tok::kw_short:
    case tok::kw_long:
    case tok::kw___int64:
    case tok::kw___int128:
    case tok::kw_signed:
    case tok::kw_unsigned:
    case tok::kw__Complex:
    case tok::kw__Imaginary:
    case tok::kw_void:
    case tok::kw_char:
    case tok::kw_wchar_t:
    case tok::kw_char8_t:
    case tok::kw_char16_t:
    case tok::kw_char32_t:
    case tok::kw_int:
    case tok::kw_half:
    case tok::kw_float:
    case tok::kw_double:
    case tok::kw__Accum:
    case tok::kw__Fract:
    case tok::kw__Float16:
    case tok::kw___float128:
    case tok::kw_bool:
    case tok::kw__Bool:
    case tok::kw__Decimal32:
    case tok::kw__Decimal64:
    case tok::kw__Decimal128:
    case tok::kw___vector:
  #define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
  #include "clang/Basic/OpenCLImageTypes.def"
  
      // struct-or-union-specifier (C99) or class-specifier (C++)
    case tok::kw_class:
    case tok::kw_struct:
    case tok::kw___interface:
    case tok::kw_union:
      // enum-specifier
    case tok::kw_enum:
  
      // typedef-name
    case tok::annot_typename:
      return true;
    }
  }
  
  /// isTypeSpecifierQualifier - Return true if the current token could be the
  /// start of a specifier-qualifier-list.
  bool Parser::isTypeSpecifierQualifier() {
    switch (Tok.getKind()) {
    default: return false;
  
    case tok::identifier:   // foo::bar
      if (TryAltiVecVectorToken())
        return true;
      LLVM_FALLTHROUGH;
    case tok::kw_typename:  // typename T::type
      // Annotate typenames and C++ scope specifiers.  If we get one, just
      // recurse to handle whatever we get.
      if (TryAnnotateTypeOrScopeToken())
        return true;
      if (Tok.is(tok::identifier))
        return false;
      return isTypeSpecifierQualifier();
  
    case tok::coloncolon:   // ::foo::bar
      if (NextToken().is(tok::kw_new) ||    // ::new
          NextToken().is(tok::kw_delete))   // ::delete
        return false;
  
      if (TryAnnotateTypeOrScopeToken())
        return true;
      return isTypeSpecifierQualifier();
  
      // GNU attributes support.
    case tok::kw___attribute:
      // GNU typeof support.
    case tok::kw_typeof:
  
      // type-specifiers
    case tok::kw_short:
    case tok::kw_long:
    case tok::kw___int64:
    case tok::kw___int128:
    case tok::kw_signed:
    case tok::kw_unsigned:
    case tok::kw__Complex:
    case tok::kw__Imaginary:
    case tok::kw_void:
    case tok::kw_char:
    case tok::kw_wchar_t:
    case tok::kw_char8_t:
    case tok::kw_char16_t:
    case tok::kw_char32_t:
    case tok::kw_int:
    case tok::kw_half:
    case tok::kw_float:
    case tok::kw_double:
    case tok::kw__Accum:
    case tok::kw__Fract:
    case tok::kw__Float16:
    case tok::kw___float128:
    case tok::kw_bool:
    case tok::kw__Bool:
    case tok::kw__Decimal32:
    case tok::kw__Decimal64:
    case tok::kw__Decimal128:
    case tok::kw___vector:
  #define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
  #include "clang/Basic/OpenCLImageTypes.def"
  
      // struct-or-union-specifier (C99) or class-specifier (C++)
    case tok::kw_class:
    case tok::kw_struct:
    case tok::kw___interface:
    case tok::kw_union:
      // enum-specifier
    case tok::kw_enum:
  
      // type-qualifier
    case tok::kw_const:
    case tok::kw_volatile:
    case tok::kw_restrict:
    case tok::kw__Sat:
  
      // Debugger support.
    case tok::kw___unknown_anytype:
  
      // typedef-name
    case tok::annot_typename:
      return true;
  
      // GNU ObjC bizarre protocol extension: <proto1,proto2> with implicit 'id'.
    case tok::less:
      return getLangOpts().ObjC;
  
    case tok::kw___cdecl:
    case tok::kw___stdcall:
    case tok::kw___fastcall:
    case tok::kw___thiscall:
    case tok::kw___regcall:
    case tok::kw___vectorcall:
    case tok::kw___w64:
    case tok::kw___ptr64:
    case tok::kw___ptr32:
    case tok::kw___pascal:
    case tok::kw___unaligned:
  
    case tok::kw__Nonnull:
    case tok::kw__Nullable:
    case tok::kw__Null_unspecified:
  
    case tok::kw___kindof:
  
    case tok::kw___private:
    case tok::kw___local:
    case tok::kw___global:
    case tok::kw___constant:
    case tok::kw___generic:
    case tok::kw___read_only:
    case tok::kw___read_write:
    case tok::kw___write_only:
      return true;
  
    case tok::kw_private:
      return getLangOpts().OpenCL;
  
    // C11 _Atomic
    case tok::kw__Atomic:
      return true;
    }
  }
  
  /// isDeclarationSpecifier() - Return true if the current token is part of a
  /// declaration specifier.
  ///
  /// \param DisambiguatingWithExpression True to indicate that the purpose of
  /// this check is to disambiguate between an expression and a declaration.
  bool Parser::isDeclarationSpecifier(bool DisambiguatingWithExpression) {
    switch (Tok.getKind()) {
    default: return false;
  
    case tok::kw_pipe:
      return (getLangOpts().OpenCL && getLangOpts().OpenCLVersion >= 200) ||
             getLangOpts().OpenCLCPlusPlus;
  
    case tok::identifier:   // foo::bar
      // Unfortunate hack to support "Class.factoryMethod" notation.
      if (getLangOpts().ObjC && NextToken().is(tok::period))
        return false;
      if (TryAltiVecVectorToken())
        return true;
      LLVM_FALLTHROUGH;
    case tok::kw_decltype: // decltype(T())::type
    case tok::kw_typename: // typename T::type
      // Annotate typenames and C++ scope specifiers.  If we get one, just
      // recurse to handle whatever we get.
      if (TryAnnotateTypeOrScopeToken())
        return true;
      if (Tok.is(tok::identifier))
        return false;
  
      // If we're in Objective-C and we have an Objective-C class type followed
      // by an identifier and then either ':' or ']', in a place where an
      // expression is permitted, then this is probably a class message send
      // missing the initial '['. In this case, we won't consider this to be
      // the start of a declaration.
      if (DisambiguatingWithExpression &&
          isStartOfObjCClassMessageMissingOpenBracket())
        return false;
  
      return isDeclarationSpecifier();
  
    case tok::coloncolon:   // ::foo::bar
      if (NextToken().is(tok::kw_new) ||    // ::new
          NextToken().is(tok::kw_delete))   // ::delete
        return false;
  
      // Annotate typenames and C++ scope specifiers.  If we get one, just
      // recurse to handle whatever we get.
      if (TryAnnotateTypeOrScopeToken())
        return true;
      return isDeclarationSpecifier();
  
      // storage-class-specifier
    case tok::kw_typedef:
    case tok::kw_extern:
    case tok::kw___private_extern__:
    case tok::kw_static:
    case tok::kw_auto:
    case tok::kw___auto_type:
    case tok::kw_register:
    case tok::kw___thread:
    case tok::kw_thread_local:
    case tok::kw__Thread_local:
  
      // Modules
    case tok::kw___module_private__:
  
      // Debugger support
    case tok::kw___unknown_anytype:
  
      // type-specifiers
    case tok::kw_short:
    case tok::kw_long:
    case tok::kw___int64:
    case tok::kw___int128:
    case tok::kw_signed:
    case tok::kw_unsigned:
    case tok::kw__Complex:
    case tok::kw__Imaginary:
    case tok::kw_void:
    case tok::kw_char:
    case tok::kw_wchar_t:
    case tok::kw_char8_t:
    case tok::kw_char16_t:
    case tok::kw_char32_t:
  
    case tok::kw_int:
    case tok::kw_half:
    case tok::kw_float:
    case tok::kw_double:
    case tok::kw__Accum:
    case tok::kw__Fract:
    case tok::kw__Float16:
    case tok::kw___float128:
    case tok::kw_bool:
    case tok::kw__Bool:
    case tok::kw__Decimal32:
    case tok::kw__Decimal64:
    case tok::kw__Decimal128:
    case tok::kw___vector:
  
      // struct-or-union-specifier (C99) or class-specifier (C++)
    case tok::kw_class:
    case tok::kw_struct:
    case tok::kw_union:
    case tok::kw___interface:
      // enum-specifier
    case tok::kw_enum:
  
      // type-qualifier
    case tok::kw_const:
    case tok::kw_volatile:
    case tok::kw_restrict:
    case tok::kw__Sat:
  
      // function-specifier
    case tok::kw_inline:
    case tok::kw_virtual:
    case tok::kw_explicit:
    case tok::kw__Noreturn:
  
      // alignment-specifier
    case tok::kw__Alignas:
  
      // friend keyword.
    case tok::kw_friend:
  
      // static_assert-declaration
    case tok::kw__Static_assert:
  
      // GNU typeof support.
    case tok::kw_typeof:
  
      // GNU attributes.
    case tok::kw___attribute:
  
      // C++11 decltype and constexpr.
    case tok::annot_decltype:
    case tok::kw_constexpr:
  
      // C++20 consteval.
    case tok::kw_consteval:
  
      // C11 _Atomic
    case tok::kw__Atomic:
      return true;
  
      // GNU ObjC bizarre protocol extension: <proto1,proto2> with implicit 'id'.
    case tok::less:
      return getLangOpts().ObjC;
  
      // typedef-name
    case tok::annot_typename:
      return !DisambiguatingWithExpression ||
             !isStartOfObjCClassMessageMissingOpenBracket();
  
    case tok::kw___declspec:
    case tok::kw___cdecl:
    case tok::kw___stdcall:
    case tok::kw___fastcall:
    case tok::kw___thiscall:
    case tok::kw___regcall:
    case tok::kw___vectorcall:
    case tok::kw___w64:
    case tok::kw___sptr:
    case tok::kw___uptr:
    case tok::kw___ptr64:
    case tok::kw___ptr32:
    case tok::kw___forceinline:
    case tok::kw___pascal:
    case tok::kw___unaligned:
  
    case tok::kw__Nonnull:
    case tok::kw__Nullable:
    case tok::kw__Null_unspecified:
  
    case tok::kw___kindof:
  
    case tok::kw___private:
    case tok::kw___local:
    case tok::kw___global:
    case tok::kw___constant:
    case tok::kw___generic:
    case tok::kw___read_only:
    case tok::kw___read_write:
    case tok::kw___write_only:
  #define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
  #include "clang/Basic/OpenCLImageTypes.def"
  
      return true;
  
    case tok::kw_private:
      return getLangOpts().OpenCL;
    }
  }
  
  bool Parser::isConstructorDeclarator(bool IsUnqualified, bool DeductionGuide) {
    TentativeParsingAction TPA(*this);
  
    // Parse the C++ scope specifier.
    CXXScopeSpec SS;
    if (ParseOptionalCXXScopeSpecifier(SS, nullptr,
                                       /*EnteringContext=*/true)) {
      TPA.Revert();
      return false;
    }
  
    // Parse the constructor name.
    if (Tok.is(tok::identifier)) {
      // We already know that we have a constructor name; just consume
      // the token.
      ConsumeToken();
    } else if (Tok.is(tok::annot_template_id)) {
      ConsumeAnnotationToken();
    } else {
      TPA.Revert();
      return false;
    }
  
    // There may be attributes here, appertaining to the constructor name or type
    // we just stepped past.
    SkipCXX11Attributes();
  
    // Current class name must be followed by a left parenthesis.
    if (Tok.isNot(tok::l_paren)) {
      TPA.Revert();
      return false;
    }
    ConsumeParen();
  
    // A right parenthesis, or ellipsis followed by a right parenthesis signals
    // that we have a constructor.
    if (Tok.is(tok::r_paren) ||
        (Tok.is(tok::ellipsis) && NextToken().is(tok::r_paren))) {
      TPA.Revert();
      return true;
    }
  
    // A C++11 attribute here signals that we have a constructor, and is an
    // attribute on the first constructor parameter.
    if (getLangOpts().CPlusPlus11 &&
        isCXX11AttributeSpecifier(/*Disambiguate*/ false,
                                  /*OuterMightBeMessageSend*/ true)) {
      TPA.Revert();
      return true;
    }
  
    // If we need to, enter the specified scope.
    DeclaratorScopeObj DeclScopeObj(*this, SS);
    if (SS.isSet() && Actions.ShouldEnterDeclaratorScope(getCurScope(), SS))
      DeclScopeObj.EnterDeclaratorScope();
  
    // Optionally skip Microsoft attributes.
    ParsedAttributes Attrs(AttrFactory);
    MaybeParseMicrosoftAttributes(Attrs);
  
    // Check whether the next token(s) are part of a declaration
    // specifier, in which case we have the start of a parameter and,
    // therefore, we know that this is a constructor.
    bool IsConstructor = false;
    if (isDeclarationSpecifier())
      IsConstructor = true;
    else if (Tok.is(tok::identifier) ||
             (Tok.is(tok::annot_cxxscope) && NextToken().is(tok::identifier))) {
      // We've seen "C ( X" or "C ( X::Y", but "X" / "X::Y" is not a type.
      // This might be a parenthesized member name, but is more likely to
      // be a constructor declaration with an invalid argument type. Keep
      // looking.
      if (Tok.is(tok::annot_cxxscope))
        ConsumeAnnotationToken();
      ConsumeToken();
  
      // If this is not a constructor, we must be parsing a declarator,
      // which must have one of the following syntactic forms (see the
      // grammar extract at the start of ParseDirectDeclarator):
      switch (Tok.getKind()) {
      case tok::l_paren:
        // C(X   (   int));
      case tok::l_square:
        // C(X   [   5]);
        // C(X   [   [attribute]]);
      case tok::coloncolon:
        // C(X   ::   Y);
        // C(X   ::   *p);
        // Assume this isn't a constructor, rather than assuming it's a
        // constructor with an unnamed parameter of an ill-formed type.
        break;
  
      case tok::r_paren:
        // C(X   )
  
        // Skip past the right-paren and any following attributes to get to
        // the function body or trailing-return-type.
        ConsumeParen();
        SkipCXX11Attributes();
  
        if (DeductionGuide) {
          // C(X) -> ... is a deduction guide.
          IsConstructor = Tok.is(tok::arrow);
          break;
        }
        if (Tok.is(tok::colon) || Tok.is(tok::kw_try)) {
          // Assume these were meant to be constructors:
          //   C(X)   :    (the name of a bit-field cannot be parenthesized).
          //   C(X)   try  (this is otherwise ill-formed).
          IsConstructor = true;
        }
        if (Tok.is(tok::semi) || Tok.is(tok::l_brace)) {
          // If we have a constructor name within the class definition,
          // assume these were meant to be constructors:
          //   C(X)   {
          //   C(X)   ;
          // ... because otherwise we would be declaring a non-static data
          // member that is ill-formed because it's of the same type as its
          // surrounding class.
          //
          // FIXME: We can actually do this whether or not the name is qualified,
          // because if it is qualified in this context it must be being used as
          // a constructor name.
          // currently, so we're somewhat conservative here.
          IsConstructor = IsUnqualified;
        }
        break;
  
      default:
        IsConstructor = true;
        break;
      }
    }
  
    TPA.Revert();
    return IsConstructor;
  }
  
  /// ParseTypeQualifierListOpt
  ///          type-qualifier-list: [C99 6.7.5]
  ///            type-qualifier
  /// [vendor]   attributes
  ///              [ only if AttrReqs & AR_VendorAttributesParsed ]
  ///            type-qualifier-list type-qualifier
  /// [vendor]   type-qualifier-list attributes
  ///              [ only if AttrReqs & AR_VendorAttributesParsed ]
  /// [C++0x]    attribute-specifier[opt] is allowed before cv-qualifier-seq
  ///              [ only if AttReqs & AR_CXX11AttributesParsed ]
  /// Note: vendor can be GNU, MS, etc and can be explicitly controlled via
  /// AttrRequirements bitmask values.
  void Parser::ParseTypeQualifierListOpt(
      DeclSpec &DS, unsigned AttrReqs, bool AtomicAllowed,
      bool IdentifierRequired,
      Optional<llvm::function_ref<void()>> CodeCompletionHandler) {
    if (standardAttributesAllowed() && (AttrReqs & AR_CXX11AttributesParsed) &&
        isCXX11AttributeSpecifier()) {
      ParsedAttributesWithRange attrs(AttrFactory);
      ParseCXX11Attributes(attrs);
      DS.takeAttributesFrom(attrs);
    }
  
    SourceLocation EndLoc;
  
    while (1) {
      bool isInvalid = false;
      const char *PrevSpec = nullptr;
      unsigned DiagID = 0;
      SourceLocation Loc = Tok.getLocation();
  
      switch (Tok.getKind()) {
      case tok::code_completion:
        if (CodeCompletionHandler)
          (*CodeCompletionHandler)();
        else
          Actions.CodeCompleteTypeQualifiers(DS);
        return cutOffParsing();
  
      case tok::kw_const:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_const   , Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
      case tok::kw_volatile:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_volatile, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
      case tok::kw_restrict:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_restrict, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
      case tok::kw__Atomic:
        if (!AtomicAllowed)
          goto DoneWithTypeQuals;
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_atomic, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
  
      // OpenCL qualifiers:
      case tok::kw_private:
        if (!getLangOpts().OpenCL)
          goto DoneWithTypeQuals;
        LLVM_FALLTHROUGH;
      case tok::kw___private:
      case tok::kw___global:
      case tok::kw___local:
      case tok::kw___constant:
      case tok::kw___generic:
      case tok::kw___read_only:
      case tok::kw___write_only:
      case tok::kw___read_write:
        ParseOpenCLQualifiers(DS.getAttributes());
        break;
  
      case tok::kw___unaligned:
        isInvalid = DS.SetTypeQual(DeclSpec::TQ_unaligned, Loc, PrevSpec, DiagID,
                                   getLangOpts());
        break;
      case tok::kw___uptr:
        // GNU libc headers in C mode use '__uptr' as an identifier which conflicts
        // with the MS modifier keyword.
        if ((AttrReqs & AR_DeclspecAttributesParsed) && !getLangOpts().CPlusPlus &&
            IdentifierRequired && DS.isEmpty() && NextToken().is(tok::semi)) {
          if (TryKeywordIdentFallback(false))
            continue;
        }
        LLVM_FALLTHROUGH;
      case tok::kw___sptr:
      case tok::kw___w64:
      case tok::kw___ptr64:
      case tok::kw___ptr32:
      case tok::kw___cdecl:
      case tok::kw___stdcall:
      case tok::kw___fastcall:
      case tok::kw___thiscall:
      case tok::kw___regcall:
      case tok::kw___vectorcall:
        if (AttrReqs & AR_DeclspecAttributesParsed) {
          ParseMicrosoftTypeAttributes(DS.getAttributes());
          continue;
        }
        goto DoneWithTypeQuals;
      case tok::kw___pascal:
        if (AttrReqs & AR_VendorAttributesParsed) {
          ParseBorlandTypeAttributes(DS.getAttributes());
          continue;
        }
        goto DoneWithTypeQuals;
  
      // Nullability type specifiers.
      case tok::kw__Nonnull:
      case tok::kw__Nullable:
      case tok::kw__Null_unspecified:
        ParseNullabilityTypeSpecifiers(DS.getAttributes());
        continue;
  
      // Objective-C 'kindof' types.
      case tok::kw___kindof:
        DS.getAttributes().addNew(Tok.getIdentifierInfo(), Loc, nullptr, Loc,
                                  nullptr, 0, ParsedAttr::AS_Keyword);
        (void)ConsumeToken();
        continue;
  
      case tok::kw___attribute:
        if (AttrReqs & AR_GNUAttributesParsedAndRejected)
          // When GNU attributes are expressly forbidden, diagnose their usage.
          Diag(Tok, diag::err_attributes_not_allowed);
  
        // Parse the attributes even if they are rejected to ensure that error
        // recovery is graceful.
        if (AttrReqs & AR_GNUAttributesParsed ||
            AttrReqs & AR_GNUAttributesParsedAndRejected) {
          ParseGNUAttributes(DS.getAttributes());
          continue; // do *not* consume the next token!
        }
        // otherwise, FALL THROUGH!
        LLVM_FALLTHROUGH;
      default:
        DoneWithTypeQuals:
        // If this is not a type-qualifier token, we're done reading type
        // qualifiers.  First verify that DeclSpec's are consistent.
        DS.Finish(Actions, Actions.getASTContext().getPrintingPolicy());
        if (EndLoc.isValid())
          DS.SetRangeEnd(EndLoc);
        return;
      }
  
      // If the specifier combination wasn't legal, issue a diagnostic.
      if (isInvalid) {
        assert(PrevSpec && "Method did not return previous specifier!");
        Diag(Tok, DiagID) << PrevSpec;
      }
      EndLoc = ConsumeToken();
    }
  }
  
  /// ParseDeclarator - Parse and verify a newly-initialized declarator.
  ///
  void Parser::ParseDeclarator(Declarator &D) {
    /// This implements the 'declarator' production in the C grammar, then checks
    /// for well-formedness and issues diagnostics.
    ParseDeclaratorInternal(D, &Parser::ParseDirectDeclarator);
  }
  
  static bool isPtrOperatorToken(tok::TokenKind Kind, const LangOptions &Lang,
                                 DeclaratorContext TheContext) {
    if (Kind == tok::star || Kind == tok::caret)
      return true;
  
    if (Kind == tok::kw_pipe &&
        ((Lang.OpenCL && Lang.OpenCLVersion >= 200) || Lang.OpenCLCPlusPlus))
      return true;
  
    if (!Lang.CPlusPlus)
      return false;
  
    if (Kind == tok::amp)
      return true;
  
    // We parse rvalue refs in C++03, because otherwise the errors are scary.
    // But we must not parse them in conversion-type-ids and new-type-ids, since
    // those can be legitimately followed by a && operator.
    // (The same thing can in theory happen after a trailing-return-type, but
    // since those are a C++11 feature, there is no rejects-valid issue there.)
    if (Kind == tok::ampamp)
      return Lang.CPlusPlus11 ||
             (TheContext != DeclaratorContext::ConversionIdContext &&
              TheContext != DeclaratorContext::CXXNewContext);
  
    return false;
  }
  
  // Indicates whether the given declarator is a pipe declarator.
  static bool isPipeDeclerator(const Declarator &D) {
    const unsigned NumTypes = D.getNumTypeObjects();
  
    for (unsigned Idx = 0; Idx != NumTypes; ++Idx)
      if (DeclaratorChunk::Pipe == D.getTypeObject(Idx).Kind)
        return true;
  
    return false;
  }
  
  /// ParseDeclaratorInternal - Parse a C or C++ declarator. The direct-declarator
  /// is parsed by the function passed to it. Pass null, and the direct-declarator
  /// isn't parsed at all, making this function effectively parse the C++
  /// ptr-operator production.
  ///
  /// If the grammar of this construct is extended, matching changes must also be
  /// made to TryParseDeclarator and MightBeDeclarator, and possibly to
  /// isConstructorDeclarator.
  ///
  ///       declarator: [C99 6.7.5] [C++ 8p4, dcl.decl]
  /// [C]     pointer[opt] direct-declarator
  /// [C++]   direct-declarator
  /// [C++]   ptr-operator declarator
  ///
  ///       pointer: [C99 6.7.5]
  ///         '*' type-qualifier-list[opt]
  ///         '*' type-qualifier-list[opt] pointer
  ///
  ///       ptr-operator:
  ///         '*' cv-qualifier-seq[opt]
  ///         '&'
  /// [C++0x] '&&'
  /// [GNU]   '&' restrict[opt] attributes[opt]
  /// [GNU?]  '&&' restrict[opt] attributes[opt]
  ///         '::'[opt] nested-name-specifier '*' cv-qualifier-seq[opt]
  void Parser::ParseDeclaratorInternal(Declarator &D,
                                       DirectDeclParseFunction DirectDeclParser) {
    if (Diags.hasAllExtensionsSilenced())
      D.setExtension();
  
    // C++ member pointers start with a '::' or a nested-name.
    // Member pointers get special handling, since there's no place for the
    // scope spec in the generic path below.
    if (getLangOpts().CPlusPlus &&
        (Tok.is(tok::coloncolon) || Tok.is(tok::kw_decltype) ||
         (Tok.is(tok::identifier) &&
          (NextToken().is(tok::coloncolon) || NextToken().is(tok::less))) ||
         Tok.is(tok::annot_cxxscope))) {
      bool EnteringContext =
          D.getContext() == DeclaratorContext::FileContext ||
          D.getContext() == DeclaratorContext::MemberContext;
      CXXScopeSpec SS;
      ParseOptionalCXXScopeSpecifier(SS, nullptr, EnteringContext);
  
      if (SS.isNotEmpty()) {
        if (Tok.isNot(tok::star)) {
          // The scope spec really belongs to the direct-declarator.
          if (D.mayHaveIdentifier())
            D.getCXXScopeSpec() = SS;
          else
            AnnotateScopeToken(SS, true);
  
          if (DirectDeclParser)
            (this->*DirectDeclParser)(D);
          return;
        }
  
        SourceLocation Loc = ConsumeToken();
        D.SetRangeEnd(Loc);
        DeclSpec DS(AttrFactory);
        ParseTypeQualifierListOpt(DS);
        D.ExtendWithDeclSpec(DS);
  
        // Recurse to parse whatever is left.
        ParseDeclaratorInternal(D, DirectDeclParser);
  
        // Sema will have to catch (syntactically invalid) pointers into global
        // scope. It has to catch pointers into namespace scope anyway.
        D.AddTypeInfo(DeclaratorChunk::getMemberPointer(
                          SS, DS.getTypeQualifiers(), DS.getEndLoc()),
                      std::move(DS.getAttributes()),
                      /* Don't replace range end. */ SourceLocation());
        return;
      }
    }
  
    tok::TokenKind Kind = Tok.getKind();
  
    if (D.getDeclSpec().isTypeSpecPipe() && !isPipeDeclerator(D)) {
      DeclSpec DS(AttrFactory);
      ParseTypeQualifierListOpt(DS);
  
      D.AddTypeInfo(
          DeclaratorChunk::getPipe(DS.getTypeQualifiers(), DS.getPipeLoc()),
          std::move(DS.getAttributes()), SourceLocation());
    }
  
    // Not a pointer, C++ reference, or block.
    if (!isPtrOperatorToken(Kind, getLangOpts(), D.getContext())) {
      if (DirectDeclParser)
        (this->*DirectDeclParser)(D);
      return;
    }
  
    // Otherwise, '*' -> pointer, '^' -> block, '&' -> lvalue reference,
    // '&&' -> rvalue reference
    SourceLocation Loc = ConsumeToken();  // Eat the *, ^, & or &&.
    D.SetRangeEnd(Loc);
  
    if (Kind == tok::star || Kind == tok::caret) {
      // Is a pointer.
      DeclSpec DS(AttrFactory);
  
      // GNU attributes are not allowed here in a new-type-id, but Declspec and
      // C++11 attributes are allowed.
      unsigned Reqs = AR_CXX11AttributesParsed | AR_DeclspecAttributesParsed |
                      ((D.getContext() != DeclaratorContext::CXXNewContext)
                           ? AR_GNUAttributesParsed
                           : AR_GNUAttributesParsedAndRejected);
      ParseTypeQualifierListOpt(DS, Reqs, true, !D.mayOmitIdentifier());
      D.ExtendWithDeclSpec(DS);
  
      // Recursively parse the declarator.
      ParseDeclaratorInternal(D, DirectDeclParser);
      if (Kind == tok::star)
        // Remember that we parsed a pointer type, and remember the type-quals.
        D.AddTypeInfo(DeclaratorChunk::getPointer(
                          DS.getTypeQualifiers(), Loc, DS.getConstSpecLoc(),
                          DS.getVolatileSpecLoc(), DS.getRestrictSpecLoc(),
                          DS.getAtomicSpecLoc(), DS.getUnalignedSpecLoc()),
                      std::move(DS.getAttributes()), SourceLocation());
      else
        // Remember that we parsed a Block type, and remember the type-quals.
        D.AddTypeInfo(
            DeclaratorChunk::getBlockPointer(DS.getTypeQualifiers(), Loc),
            std::move(DS.getAttributes()), SourceLocation());
    } else {
      // Is a reference
      DeclSpec DS(AttrFactory);
  
      // Complain about rvalue references in C++03, but then go on and build
      // the declarator.
      if (Kind == tok::ampamp)
        Diag(Loc, getLangOpts().CPlusPlus11 ?
             diag::warn_cxx98_compat_rvalue_reference :
             diag::ext_rvalue_reference);
  
      // GNU-style and C++11 attributes are allowed here, as is restrict.
      ParseTypeQualifierListOpt(DS);
      D.ExtendWithDeclSpec(DS);
  
      // C++ 8.3.2p1: cv-qualified references are ill-formed except when the
      // cv-qualifiers are introduced through the use of a typedef or of a
      // template type argument, in which case the cv-qualifiers are ignored.
      if (DS.getTypeQualifiers() != DeclSpec::TQ_unspecified) {
        if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
          Diag(DS.getConstSpecLoc(),
               diag::err_invalid_reference_qualifier_application) << "const";
        if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
          Diag(DS.getVolatileSpecLoc(),
               diag::err_invalid_reference_qualifier_application) << "volatile";
        // 'restrict' is permitted as an extension.
        if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
          Diag(DS.getAtomicSpecLoc(),
               diag::err_invalid_reference_qualifier_application) << "_Atomic";
      }
  
      // Recursively parse the declarator.
      ParseDeclaratorInternal(D, DirectDeclParser);
  
      if (D.getNumTypeObjects() > 0) {
        // C++ [dcl.ref]p4: There shall be no references to references.
        DeclaratorChunk& InnerChunk = D.getTypeObject(D.getNumTypeObjects() - 1);
        if (InnerChunk.Kind == DeclaratorChunk::Reference) {
          if (const IdentifierInfo *II = D.getIdentifier())
            Diag(InnerChunk.Loc, diag::err_illegal_decl_reference_to_reference)
             << II;
          else
            Diag(InnerChunk.Loc, diag::err_illegal_decl_reference_to_reference)
              << "type name";
  
          // Once we've complained about the reference-to-reference, we
          // can go ahead and build the (technically ill-formed)
          // declarator: reference collapsing will take care of it.
        }
      }
  
      // Remember that we parsed a reference type.
      D.AddTypeInfo(DeclaratorChunk::getReference(DS.getTypeQualifiers(), Loc,
                                                  Kind == tok::amp),
                    std::move(DS.getAttributes()), SourceLocation());
    }
  }
  
  // When correcting from misplaced brackets before the identifier, the location
  // is saved inside the declarator so that other diagnostic messages can use
  // them.  This extracts and returns that location, or returns the provided
  // location if a stored location does not exist.
  static SourceLocation getMissingDeclaratorIdLoc(Declarator &D,
                                                  SourceLocation Loc) {
    if (D.getName().StartLocation.isInvalid() &&
        D.getName().EndLocation.isValid())
      return D.getName().EndLocation;
  
    return Loc;
  }
  
  /// ParseDirectDeclarator
  ///       direct-declarator: [C99 6.7.5]
  /// [C99]   identifier
  ///         '(' declarator ')'
  /// [GNU]   '(' attributes declarator ')'
  /// [C90]   direct-declarator '[' constant-expression[opt] ']'
  /// [C99]   direct-declarator '[' type-qual-list[opt] assignment-expr[opt] ']'
  /// [C99]   direct-declarator '[' 'static' type-qual-list[opt] assign-expr ']'
  /// [C99]   direct-declarator '[' type-qual-list 'static' assignment-expr ']'
  /// [C99]   direct-declarator '[' type-qual-list[opt] '*' ']'
  /// [C++11] direct-declarator '[' constant-expression[opt] ']'
  ///                    attribute-specifier-seq[opt]
  ///         direct-declarator '(' parameter-type-list ')'
  ///         direct-declarator '(' identifier-list[opt] ')'
  /// [GNU]   direct-declarator '(' parameter-forward-declarations
  ///                    parameter-type-list[opt] ')'
  /// [C++]   direct-declarator '(' parameter-declaration-clause ')'
  ///                    cv-qualifier-seq[opt] exception-specification[opt]
  /// [C++11] direct-declarator '(' parameter-declaration-clause ')'
  ///                    attribute-specifier-seq[opt] cv-qualifier-seq[opt]
  ///                    ref-qualifier[opt] exception-specification[opt]
  /// [C++]   declarator-id
  /// [C++11] declarator-id attribute-specifier-seq[opt]
  ///
  ///       declarator-id: [C++ 8]
  ///         '...'[opt] id-expression
  ///         '::'[opt] nested-name-specifier[opt] type-name
  ///
  ///       id-expression: [C++ 5.1]
  ///         unqualified-id
  ///         qualified-id
  ///
  ///       unqualified-id: [C++ 5.1]
  ///         identifier
  ///         operator-function-id
  ///         conversion-function-id
  ///          '~' class-name
  ///         template-id
  ///
  /// C++17 adds the following, which we also handle here:
  ///
  ///       simple-declaration:
  ///         <decl-spec> '[' identifier-list ']' brace-or-equal-initializer ';'
  ///
  /// Note, any additional constructs added here may need corresponding changes
  /// in isConstructorDeclarator.
  void Parser::ParseDirectDeclarator(Declarator &D) {
    DeclaratorScopeObj DeclScopeObj(*this, D.getCXXScopeSpec());
  
    if (getLangOpts().CPlusPlus && D.mayHaveIdentifier()) {
      // This might be a C++17 structured binding.
      if (Tok.is(tok::l_square) && !D.mayOmitIdentifier() &&
          D.getCXXScopeSpec().isEmpty())
        return ParseDecompositionDeclarator(D);
  
      // Don't parse FOO:BAR as if it were a typo for FOO::BAR inside a class, in
      // this context it is a bitfield. Also in range-based for statement colon
      // may delimit for-range-declaration.
      ColonProtectionRAIIObject X(
          *this, D.getContext() == DeclaratorContext::MemberContext ||
                     (D.getContext() == DeclaratorContext::ForContext &&
                      getLangOpts().CPlusPlus11));
  
      // ParseDeclaratorInternal might already have parsed the scope.
      if (D.getCXXScopeSpec().isEmpty()) {
        bool EnteringContext =
            D.getContext() == DeclaratorContext::FileContext ||
            D.getContext() == DeclaratorContext::MemberContext;
        ParseOptionalCXXScopeSpecifier(D.getCXXScopeSpec(), nullptr,
                                       EnteringContext);
      }
  
      if (D.getCXXScopeSpec().isValid()) {
        if (Actions.ShouldEnterDeclaratorScope(getCurScope(),
                                               D.getCXXScopeSpec()))
          // Change the declaration context for name lookup, until this function
          // is exited (and the declarator has been parsed).
          DeclScopeObj.EnterDeclaratorScope();
        else if (getObjCDeclContext()) {
          // Ensure that we don't interpret the next token as an identifier when
          // dealing with declarations in an Objective-C container.
          D.SetIdentifier(nullptr, Tok.getLocation());
          D.setInvalidType(true);
          ConsumeToken();
          goto PastIdentifier;
        }
      }
  
      // C++0x [dcl.fct]p14:
      //   There is a syntactic ambiguity when an ellipsis occurs at the end of a
      //   parameter-declaration-clause without a preceding comma. In this case,
      //   the ellipsis is parsed as part of the abstract-declarator if the type
      //   of the parameter either names a template parameter pack that has not
      //   been expanded or contains auto; otherwise, it is parsed as part of the
      //   parameter-declaration-clause.
      if (Tok.is(tok::ellipsis) && D.getCXXScopeSpec().isEmpty() &&
          !((D.getContext() == DeclaratorContext::PrototypeContext ||
             D.getContext() == DeclaratorContext::LambdaExprParameterContext ||
             D.getContext() == DeclaratorContext::BlockLiteralContext) &&
            NextToken().is(tok::r_paren) &&
            !D.hasGroupingParens() &&
            !Actions.containsUnexpandedParameterPacks(D) &&
            D.getDeclSpec().getTypeSpecType() != TST_auto)) {
        SourceLocation EllipsisLoc = ConsumeToken();
        if (isPtrOperatorToken(Tok.getKind(), getLangOpts(), D.getContext())) {
          // The ellipsis was put in the wrong place. Recover, and explain to
          // the user what they should have done.
          ParseDeclarator(D);
          if (EllipsisLoc.isValid())
            DiagnoseMisplacedEllipsisInDeclarator(EllipsisLoc, D);
          return;
        } else
          D.setEllipsisLoc(EllipsisLoc);
  
        // The ellipsis can't be followed by a parenthesized declarator. We
        // check for that in ParseParenDeclarator, after we have disambiguated
        // the l_paren token.
      }
  
      if (Tok.isOneOf(tok::identifier, tok::kw_operator, tok::annot_template_id,
                      tok::tilde)) {
        // We found something that indicates the start of an unqualified-id.
        // Parse that unqualified-id.
        bool AllowConstructorName;
        bool AllowDeductionGuide;
        if (D.getDeclSpec().hasTypeSpecifier()) {
          AllowConstructorName = false;
          AllowDeductionGuide = false;
        } else if (D.getCXXScopeSpec().isSet()) {
          AllowConstructorName =
            (D.getContext() == DeclaratorContext::FileContext ||
             D.getContext() == DeclaratorContext::MemberContext);
          AllowDeductionGuide = false;
        } else {
          AllowConstructorName =
              (D.getContext() == DeclaratorContext::MemberContext);
          AllowDeductionGuide =
            (D.getContext() == DeclaratorContext::FileContext ||
             D.getContext() == DeclaratorContext::MemberContext);
        }
  
        bool HadScope = D.getCXXScopeSpec().isValid();
        if (ParseUnqualifiedId(D.getCXXScopeSpec(),
                               /*EnteringContext=*/true,
                               /*AllowDestructorName=*/true, AllowConstructorName,
                               AllowDeductionGuide, nullptr, nullptr,
                               D.getName()) ||
            // Once we're past the identifier, if the scope was bad, mark the
            // whole declarator bad.
            D.getCXXScopeSpec().isInvalid()) {
          D.SetIdentifier(nullptr, Tok.getLocation());
          D.setInvalidType(true);
        } else {
          // ParseUnqualifiedId might have parsed a scope specifier during error
          // recovery. If it did so, enter that scope.
          if (!HadScope && D.getCXXScopeSpec().isValid() &&
              Actions.ShouldEnterDeclaratorScope(getCurScope(),
                                                 D.getCXXScopeSpec()))
            DeclScopeObj.EnterDeclaratorScope();
  
          // Parsed the unqualified-id; update range information and move along.
          if (D.getSourceRange().getBegin().isInvalid())
            D.SetRangeBegin(D.getName().getSourceRange().getBegin());
          D.SetRangeEnd(D.getName().getSourceRange().getEnd());
        }
        goto PastIdentifier;
      }
  
      if (D.getCXXScopeSpec().isNotEmpty()) {
        // We have a scope specifier but no following unqualified-id.
        Diag(PP.getLocForEndOfToken(D.getCXXScopeSpec().getEndLoc()),
             diag::err_expected_unqualified_id)
            << /*C++*/1;
        D.SetIdentifier(nullptr, Tok.getLocation());
        goto PastIdentifier;
      }
    } else if (Tok.is(tok::identifier) && D.mayHaveIdentifier()) {
      assert(!getLangOpts().CPlusPlus &&
             "There's a C++-specific check for tok::identifier above");
      assert(Tok.getIdentifierInfo() && "Not an identifier?");
      D.SetIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
      D.SetRangeEnd(Tok.getLocation());
      ConsumeToken();
      goto PastIdentifier;
    } else if (Tok.is(tok::identifier) && !D.mayHaveIdentifier()) {
      // We're not allowed an identifier here, but we got one. Try to figure out
      // if the user was trying to attach a name to the type, or whether the name
      // is some unrelated trailing syntax.
      bool DiagnoseIdentifier = false;
      if (D.hasGroupingParens())
        // An identifier within parens is unlikely to be intended to be anything
        // other than a name being "declared".
        DiagnoseIdentifier = true;
      else if (D.getContext() == DeclaratorContext::TemplateArgContext)
        // T<int N> is an accidental identifier; T<int N indicates a missing '>'.
        DiagnoseIdentifier =
            NextToken().isOneOf(tok::comma, tok::greater, tok::greatergreater);
      else if (D.getContext() == DeclaratorContext::AliasDeclContext ||
               D.getContext() == DeclaratorContext::AliasTemplateContext)
        // The most likely error is that the ';' was forgotten.
        DiagnoseIdentifier = NextToken().isOneOf(tok::comma, tok::semi);
      else if ((D.getContext() == DeclaratorContext::TrailingReturnContext ||
                D.getContext() == DeclaratorContext::TrailingReturnVarContext) &&
               !isCXX11VirtSpecifier(Tok))
        DiagnoseIdentifier = NextToken().isOneOf(
            tok::comma, tok::semi, tok::equal, tok::l_brace, tok::kw_try);
      if (DiagnoseIdentifier) {
        Diag(Tok.getLocation(), diag::err_unexpected_unqualified_id)
          << FixItHint::CreateRemoval(Tok.getLocation());
        D.SetIdentifier(nullptr, Tok.getLocation());
        ConsumeToken();
        goto PastIdentifier;
      }
    }
  
    if (Tok.is(tok::l_paren)) {
      // If this might be an abstract-declarator followed by a direct-initializer,
      // check whether this is a valid declarator chunk. If it can't be, assume
      // that it's an initializer instead.
      if (D.mayOmitIdentifier() && D.mayBeFollowedByCXXDirectInit()) {
        RevertingTentativeParsingAction PA(*this);
        if (TryParseDeclarator(true, D.mayHaveIdentifier(), true) ==
                TPResult::False) {
          D.SetIdentifier(nullptr, Tok.getLocation());
          goto PastIdentifier;
        }
      }
  
      // direct-declarator: '(' declarator ')'
      // direct-declarator: '(' attributes declarator ')'
      // Example: 'char (*X)'   or 'int (*XX)(void)'
      ParseParenDeclarator(D);
  
      // If the declarator was parenthesized, we entered the declarator
      // scope when parsing the parenthesized declarator, then exited
      // the scope already. Re-enter the scope, if we need to.
      if (D.getCXXScopeSpec().isSet()) {
        // If there was an error parsing parenthesized declarator, declarator
        // scope may have been entered before. Don't do it again.
        if (!D.isInvalidType() &&
            Actions.ShouldEnterDeclaratorScope(getCurScope(),
                                               D.getCXXScopeSpec()))
          // Change the declaration context for name lookup, until this function
          // is exited (and the declarator has been parsed).
          DeclScopeObj.EnterDeclaratorScope();
      }
    } else if (D.mayOmitIdentifier()) {
      // This could be something simple like "int" (in which case the declarator
      // portion is empty), if an abstract-declarator is allowed.
      D.SetIdentifier(nullptr, Tok.getLocation());
  
      // The grammar for abstract-pack-declarator does not allow grouping parens.
      // FIXME: Revisit this once core issue 1488 is resolved.
      if (D.hasEllipsis() && D.hasGroupingParens())
        Diag(PP.getLocForEndOfToken(D.getEllipsisLoc()),
             diag::ext_abstract_pack_declarator_parens);
    } else {
      if (Tok.getKind() == tok::annot_pragma_parser_crash)
        LLVM_BUILTIN_TRAP;
      if (Tok.is(tok::l_square))
        return ParseMisplacedBracketDeclarator(D);
      if (D.getContext() == DeclaratorContext::MemberContext) {
        // Objective-C++: Detect C++ keywords and try to prevent further errors by
        // treating these keyword as valid member names.
        if (getLangOpts().ObjC && getLangOpts().CPlusPlus &&
            Tok.getIdentifierInfo() &&
            Tok.getIdentifierInfo()->isCPlusPlusKeyword(getLangOpts())) {
          Diag(getMissingDeclaratorIdLoc(D, Tok.getLocation()),
               diag::err_expected_member_name_or_semi_objcxx_keyword)
              << Tok.getIdentifierInfo()
              << (D.getDeclSpec().isEmpty() ? SourceRange()
                                            : D.getDeclSpec().getSourceRange());
          D.SetIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
          D.SetRangeEnd(Tok.getLocation());
          ConsumeToken();
          goto PastIdentifier;
        }
        Diag(getMissingDeclaratorIdLoc(D, Tok.getLocation()),
             diag::err_expected_member_name_or_semi)
            << (D.getDeclSpec().isEmpty() ? SourceRange()
                                          : D.getDeclSpec().getSourceRange());
      } else if (getLangOpts().CPlusPlus) {
        if (Tok.isOneOf(tok::period, tok::arrow))
          Diag(Tok, diag::err_invalid_operator_on_type) << Tok.is(tok::arrow);
        else {
          SourceLocation Loc = D.getCXXScopeSpec().getEndLoc();
          if (Tok.isAtStartOfLine() && Loc.isValid())
            Diag(PP.getLocForEndOfToken(Loc), diag::err_expected_unqualified_id)
                << getLangOpts().CPlusPlus;
          else
            Diag(getMissingDeclaratorIdLoc(D, Tok.getLocation()),
                 diag::err_expected_unqualified_id)
                << getLangOpts().CPlusPlus;
        }
      } else {
        Diag(getMissingDeclaratorIdLoc(D, Tok.getLocation()),
             diag::err_expected_either)
            << tok::identifier << tok::l_paren;
      }
      D.SetIdentifier(nullptr, Tok.getLocation());
      D.setInvalidType(true);
    }
  
   PastIdentifier:
    assert(D.isPastIdentifier() &&
           "Haven't past the location of the identifier yet?");
  
    // Don't parse attributes unless we have parsed an unparenthesized name.
    if (D.hasName() && !D.getNumTypeObjects())
      MaybeParseCXX11Attributes(D);
  
    while (1) {
      if (Tok.is(tok::l_paren)) {
        // Enter function-declaration scope, limiting any declarators to the
        // function prototype scope, including parameter declarators.
        ParseScope PrototypeScope(this,
                                  Scope::FunctionPrototypeScope|Scope::DeclScope|
                                  (D.isFunctionDeclaratorAFunctionDeclaration()
                                     ? Scope::FunctionDeclarationScope : 0));
  
        // The paren may be part of a C++ direct initializer, eg. "int x(1);".
        // In such a case, check if we actually have a function declarator; if it
        // is not, the declarator has been fully parsed.
        bool IsAmbiguous = false;
        if (getLangOpts().CPlusPlus && D.mayBeFollowedByCXXDirectInit()) {
          // The name of the declarator, if any, is tentatively declared within
          // a possible direct initializer.
          TentativelyDeclaredIdentifiers.push_back(D.getIdentifier());
          bool IsFunctionDecl = isCXXFunctionDeclarator(&IsAmbiguous);
          TentativelyDeclaredIdentifiers.pop_back();
          if (!IsFunctionDecl)
            break;
        }
        ParsedAttributes attrs(AttrFactory);
        BalancedDelimiterTracker T(*this, tok::l_paren);
        T.consumeOpen();
        ParseFunctionDeclarator(D, attrs, T, IsAmbiguous);
        PrototypeScope.Exit();
      } else if (Tok.is(tok::l_square)) {
        ParseBracketDeclarator(D);
      } else if (Tok.is(tok::kw_requires)) {
        if (D.hasGroupingParens())
          // This declarator is declaring a function, but the requires clause is
          // in the wrong place:
          //   void (f() requires true);
          // instead of
          //   void f() requires true;
          // or
          //   void (f()) requires true;
          Diag(Tok, diag::err_requires_clause_inside_parens);
        else
          // This requires clause is in the right place, but will be parsed later
          // as part of the init-declarator, member-declarator or
          // function-definition.
          break;
        ConsumeToken();
        ExprResult TrailingRequiresClause = Actions.CorrectDelayedTyposInExpr(
            ParseConstraintLogicalOrExpression());
        if (TrailingRequiresClause.isUsable() && D.isFunctionDeclarator() &&
            !D.hasTrailingRequiresClause())
          // We're already ill-formed if we got here but we'll accept it anyway.
          D.setTrailingRequiresClause(TrailingRequiresClause.get());
      } else {
        break;
      }
    }
  }
  
  void Parser::ParseDecompositionDeclarator(Declarator &D) {
    assert(Tok.is(tok::l_square));
  
    // If this doesn't look like a structured binding, maybe it's a misplaced
    // array declarator.
    // FIXME: Consume the l_square first so we don't need extra lookahead for
    // this.
    if (!(NextToken().is(tok::identifier) &&
          GetLookAheadToken(2).isOneOf(tok::comma, tok::r_square)) &&
        !(NextToken().is(tok::r_square) &&
          GetLookAheadToken(2).isOneOf(tok::equal, tok::l_brace)))
      return ParseMisplacedBracketDeclarator(D);
  
    BalancedDelimiterTracker T(*this, tok::l_square);
    T.consumeOpen();
  
    SmallVector<DecompositionDeclarator::Binding, 32> Bindings;
    while (Tok.isNot(tok::r_square)) {
      if (!Bindings.empty()) {
        if (Tok.is(tok::comma))
          ConsumeToken();
        else {
          if (Tok.is(tok::identifier)) {
            SourceLocation EndLoc = getEndOfPreviousToken();
            Diag(EndLoc, diag::err_expected)
                << tok::comma << FixItHint::CreateInsertion(EndLoc, ",");
          } else {
            Diag(Tok, diag::err_expected_comma_or_rsquare);
          }
  
          SkipUntil(tok::r_square, tok::comma, tok::identifier,
                    StopAtSemi | StopBeforeMatch);
          if (Tok.is(tok::comma))
            ConsumeToken();
          else if (Tok.isNot(tok::identifier))
            break;
        }
      }
  
      if (Tok.isNot(tok::identifier)) {
        Diag(Tok, diag::err_expected) << tok::identifier;
        break;
      }
  
      Bindings.push_back({Tok.getIdentifierInfo(), Tok.getLocation()});
      ConsumeToken();
    }
  
    if (Tok.isNot(tok::r_square))
      // We've already diagnosed a problem here.
      T.skipToEnd();
    else {
      // C++17 does not allow the identifier-list in a structured binding
      // to be empty.
      if (Bindings.empty())
        Diag(Tok.getLocation(), diag::ext_decomp_decl_empty);
  
      T.consumeClose();
    }
  
    return D.setDecompositionBindings(T.getOpenLocation(), Bindings,
                                      T.getCloseLocation());
  }
  
  /// ParseParenDeclarator - We parsed the declarator D up to a paren.  This is
  /// only called before the identifier, so these are most likely just grouping
  /// parens for precedence.  If we find that these are actually function
  /// parameter parens in an abstract-declarator, we call ParseFunctionDeclarator.
  ///
  ///       direct-declarator:
  ///         '(' declarator ')'
  /// [GNU]   '(' attributes declarator ')'
  ///         direct-declarator '(' parameter-type-list ')'
  ///         direct-declarator '(' identifier-list[opt] ')'
  /// [GNU]   direct-declarator '(' parameter-forward-declarations
  ///                    parameter-type-list[opt] ')'
  ///
  void Parser::ParseParenDeclarator(Declarator &D) {
    BalancedDelimiterTracker T(*this, tok::l_paren);
    T.consumeOpen();
  
    assert(!D.isPastIdentifier() && "Should be called before passing identifier");
  
    // Eat any attributes before we look at whether this is a grouping or function
    // declarator paren.  If this is a grouping paren, the attribute applies to
    // the type being built up, for example:
    //     int (__attribute__(()) *x)(long y)
    // If this ends up not being a grouping paren, the attribute applies to the
    // first argument, for example:
    //     int (__attribute__(()) int x)
    // In either case, we need to eat any attributes to be able to determine what
    // sort of paren this is.
    //
    ParsedAttributes attrs(AttrFactory);
    bool RequiresArg = false;
    if (Tok.is(tok::kw___attribute)) {
      ParseGNUAttributes(attrs);
  
      // We require that the argument list (if this is a non-grouping paren) be
      // present even if the attribute list was empty.
      RequiresArg = true;
    }
  
    // Eat any Microsoft extensions.
    ParseMicrosoftTypeAttributes(attrs);
  
    // Eat any Borland extensions.
    if  (Tok.is(tok::kw___pascal))
      ParseBorlandTypeAttributes(attrs);
  
    // If we haven't past the identifier yet (or where the identifier would be
    // stored, if this is an abstract declarator), then this is probably just
    // grouping parens. However, if this could be an abstract-declarator, then
    // this could also be the start of function arguments (consider 'void()').
    bool isGrouping;
  
    if (!D.mayOmitIdentifier()) {
      // If this can't be an abstract-declarator, this *must* be a grouping
      // paren, because we haven't seen the identifier yet.
      isGrouping = true;
    } else if (Tok.is(tok::r_paren) ||           // 'int()' is a function.
               (getLangOpts().CPlusPlus && Tok.is(tok::ellipsis) &&
                NextToken().is(tok::r_paren)) || // C++ int(...)
               isDeclarationSpecifier() ||       // 'int(int)' is a function.
               isCXX11AttributeSpecifier()) {    // 'int([[]]int)' is a function.
      // This handles C99 6.7.5.3p11: in "typedef int X; void foo(X)", X is
      // considered to be a type, not a K&R identifier-list.
      isGrouping = false;
    } else {
      // Otherwise, this is a grouping paren, e.g. 'int (*X)' or 'int(X)'.
      isGrouping = true;
    }
  
    // If this is a grouping paren, handle:
    // direct-declarator: '(' declarator ')'
    // direct-declarator: '(' attributes declarator ')'
    if (isGrouping) {
      SourceLocation EllipsisLoc = D.getEllipsisLoc();
      D.setEllipsisLoc(SourceLocation());
  
      bool hadGroupingParens = D.hasGroupingParens();
      D.setGroupingParens(true);
      ParseDeclaratorInternal(D, &Parser::ParseDirectDeclarator);
      // Match the ')'.
      T.consumeClose();
      D.AddTypeInfo(
          DeclaratorChunk::getParen(T.getOpenLocation(), T.getCloseLocation()),
          std::move(attrs), T.getCloseLocation());
  
      D.setGroupingParens(hadGroupingParens);
  
      // An ellipsis cannot be placed outside parentheses.
      if (EllipsisLoc.isValid())
        DiagnoseMisplacedEllipsisInDeclarator(EllipsisLoc, D);
  
      return;
    }
  
    // Okay, if this wasn't a grouping paren, it must be the start of a function
    // argument list.  Recognize that this declarator will never have an
    // identifier (and remember where it would have been), then call into
    // ParseFunctionDeclarator to handle of argument list.
    D.SetIdentifier(nullptr, Tok.getLocation());
  
    // Enter function-declaration scope, limiting any declarators to the
    // function prototype scope, including parameter declarators.
    ParseScope PrototypeScope(this,
                              Scope::FunctionPrototypeScope | Scope::DeclScope |
                              (D.isFunctionDeclaratorAFunctionDeclaration()
                                 ? Scope::FunctionDeclarationScope : 0));
    ParseFunctionDeclarator(D, attrs, T, false, RequiresArg);
    PrototypeScope.Exit();
  }
  
  void Parser::InitCXXThisScopeForDeclaratorIfRelevant(
      const Declarator &D, const DeclSpec &DS,
      llvm::Optional<Sema::CXXThisScopeRAII> &ThisScope) {
    // C++11 [expr.prim.general]p3:
    //   If a declaration declares a member function or member function
    //   template of a class X, the expression this is a prvalue of type
    //   "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
    //   and the end of the function-definition, member-declarator, or
    //   declarator.
    // FIXME: currently, "static" case isn't handled correctly.
    bool IsCXX11MemberFunction = getLangOpts().CPlusPlus11 &&
          D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
          (D.getContext() == DeclaratorContext::MemberContext
           ? !D.getDeclSpec().isFriendSpecified()
           : D.getContext() == DeclaratorContext::FileContext &&
             D.getCXXScopeSpec().isValid() &&
             Actions.CurContext->isRecord());
    if (!IsCXX11MemberFunction)
      return;
  
    Qualifiers Q = Qualifiers::fromCVRUMask(DS.getTypeQualifiers());
    if (D.getDeclSpec().hasConstexprSpecifier() && !getLangOpts().CPlusPlus14)
      Q.addConst();
    // FIXME: Collect C++ address spaces.
    // If there are multiple different address spaces, the source is invalid.
    // Carry on using the first addr space for the qualifiers of 'this'.
    // The diagnostic will be given later while creating the function
    // prototype for the method.
    if (getLangOpts().OpenCLCPlusPlus) {
      for (ParsedAttr &attr : DS.getAttributes()) {
        LangAS ASIdx = attr.asOpenCLLangAS();
        if (ASIdx != LangAS::Default) {
          Q.addAddressSpace(ASIdx);
          break;
        }
      }
    }
    ThisScope.emplace(Actions, dyn_cast<CXXRecordDecl>(Actions.CurContext), Q,
                      IsCXX11MemberFunction);
  }
  
  /// ParseFunctionDeclarator - We are after the identifier and have parsed the
  /// declarator D up to a paren, which indicates that we are parsing function
  /// arguments.
  ///
  /// If FirstArgAttrs is non-null, then the caller parsed those arguments
  /// immediately after the open paren - they should be considered to be the
  /// first argument of a parameter.
  ///
  /// If RequiresArg is true, then the first argument of the function is required
  /// to be present and required to not be an identifier list.
  ///
  /// For C++, after the parameter-list, it also parses the cv-qualifier-seq[opt],
  /// (C++11) ref-qualifier[opt], exception-specification[opt],
  /// (C++11) attribute-specifier-seq[opt], (C++11) trailing-return-type[opt] and
  /// (C++2a) the trailing requires-clause.
  ///
  /// [C++11] exception-specification:
  ///           dynamic-exception-specification
  ///           noexcept-specification
  ///
  void Parser::ParseFunctionDeclarator(Declarator &D,
                                       ParsedAttributes &FirstArgAttrs,
                                       BalancedDelimiterTracker &Tracker,
                                       bool IsAmbiguous,
                                       bool RequiresArg) {
    assert(getCurScope()->isFunctionPrototypeScope() &&
           "Should call from a Function scope");
    // lparen is already consumed!
    assert(D.isPastIdentifier() && "Should not call before identifier!");
  
    // This should be true when the function has typed arguments.
    // Otherwise, it is treated as a K&R-style function.
    bool HasProto = false;
    // Build up an array of information about the parsed arguments.
    SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
    // Remember where we see an ellipsis, if any.
    SourceLocation EllipsisLoc;
  
    DeclSpec DS(AttrFactory);
    bool RefQualifierIsLValueRef = true;
    SourceLocation RefQualifierLoc;
    ExceptionSpecificationType ESpecType = EST_None;
    SourceRange ESpecRange;
    SmallVector<ParsedType, 2> DynamicExceptions;
    SmallVector<SourceRange, 2> DynamicExceptionRanges;
    ExprResult NoexceptExpr;
    CachedTokens *ExceptionSpecTokens = nullptr;
    ParsedAttributesWithRange FnAttrs(AttrFactory);
    TypeResult TrailingReturnType;
  
    /* LocalEndLoc is the end location for the local FunctionTypeLoc.
       EndLoc is the end location for the function declarator.
       They differ for trailing return types. */
    SourceLocation StartLoc, LocalEndLoc, EndLoc;
    SourceLocation LParenLoc, RParenLoc;
    LParenLoc = Tracker.getOpenLocation();
    StartLoc = LParenLoc;
  
    if (isFunctionDeclaratorIdentifierList()) {
      if (RequiresArg)
        Diag(Tok, diag::err_argument_required_after_attribute);
  
      ParseFunctionDeclaratorIdentifierList(D, ParamInfo);
  
      Tracker.consumeClose();
      RParenLoc = Tracker.getCloseLocation();
      LocalEndLoc = RParenLoc;
      EndLoc = RParenLoc;
  
      // If there are attributes following the identifier list, parse them and
      // prohibit them.
      MaybeParseCXX11Attributes(FnAttrs);
      ProhibitAttributes(FnAttrs);
    } else {
      if (Tok.isNot(tok::r_paren))
        ParseParameterDeclarationClause(D.getContext(), FirstArgAttrs, ParamInfo,
                                        EllipsisLoc);
      else if (RequiresArg)
        Diag(Tok, diag::err_argument_required_after_attribute);
  
      HasProto = ParamInfo.size() || getLangOpts().CPlusPlus
                                  || getLangOpts().OpenCL;
  
      // If we have the closing ')', eat it.
      Tracker.consumeClose();
      RParenLoc = Tracker.getCloseLocation();
      LocalEndLoc = RParenLoc;
      EndLoc = RParenLoc;
  
      if (getLangOpts().CPlusPlus) {
        // FIXME: Accept these components in any order, and produce fixits to
        // correct the order if the user gets it wrong. Ideally we should deal
        // with the pure-specifier in the same way.
  
        // Parse cv-qualifier-seq[opt].
        ParseTypeQualifierListOpt(DS, AR_NoAttributesParsed,
                                  /*AtomicAllowed*/ false,
                                  /*IdentifierRequired=*/false,
                                  llvm::function_ref<void()>([&]() {
                                    Actions.CodeCompleteFunctionQualifiers(DS, D);
                                  }));
        if (!DS.getSourceRange().getEnd().isInvalid()) {
          EndLoc = DS.getSourceRange().getEnd();
        }
  
        // Parse ref-qualifier[opt].
        if (ParseRefQualifier(RefQualifierIsLValueRef, RefQualifierLoc))
          EndLoc = RefQualifierLoc;
  
        llvm::Optional<Sema::CXXThisScopeRAII> ThisScope;
        InitCXXThisScopeForDeclaratorIfRelevant(D, DS, ThisScope);
  
        // Parse exception-specification[opt].
        bool Delayed = D.isFirstDeclarationOfMember() &&
                       D.isFunctionDeclaratorAFunctionDeclaration();
        if (Delayed && Actions.isLibstdcxxEagerExceptionSpecHack(D) &&
            GetLookAheadToken(0).is(tok::kw_noexcept) &&
            GetLookAheadToken(1).is(tok::l_paren) &&
            GetLookAheadToken(2).is(tok::kw_noexcept) &&
            GetLookAheadToken(3).is(tok::l_paren) &&
            GetLookAheadToken(4).is(tok::identifier) &&
            GetLookAheadToken(4).getIdentifierInfo()->isStr("swap")) {
          // HACK: We've got an exception-specification
          //   noexcept(noexcept(swap(...)))
          // or
          //   noexcept(noexcept(swap(...)) && noexcept(swap(...)))
          // on a 'swap' member function. This is a libstdc++ bug; the lookup
          // for 'swap' will only find the function we're currently declaring,
          // whereas it expects to find a non-member swap through ADL. Turn off
          // delayed parsing to give it a chance to find what it expects.
          Delayed = false;
        }
        ESpecType = tryParseExceptionSpecification(Delayed,
                                                   ESpecRange,
                                                   DynamicExceptions,
                                                   DynamicExceptionRanges,
                                                   NoexceptExpr,
                                                   ExceptionSpecTokens);
        if (ESpecType != EST_None)
          EndLoc = ESpecRange.getEnd();
  
        // Parse attribute-specifier-seq[opt]. Per DR 979 and DR 1297, this goes
        // after the exception-specification.
        MaybeParseCXX11Attributes(FnAttrs);
  
        // Parse trailing-return-type[opt].
        LocalEndLoc = EndLoc;
        if (getLangOpts().CPlusPlus11 && Tok.is(tok::arrow)) {
          Diag(Tok, diag::warn_cxx98_compat_trailing_return_type);
          if (D.getDeclSpec().getTypeSpecType() == TST_auto)
            StartLoc = D.getDeclSpec().getTypeSpecTypeLoc();
          LocalEndLoc = Tok.getLocation();
          SourceRange Range;
          TrailingReturnType =
              ParseTrailingReturnType(Range, D.mayBeFollowedByCXXDirectInit());
          EndLoc = Range.getEnd();
        }
      } else if (standardAttributesAllowed()) {
        MaybeParseCXX11Attributes(FnAttrs);
      }
    }
  
    // Collect non-parameter declarations from the prototype if this is a function
    // declaration. They will be moved into the scope of the function. Only do
    // this in C and not C++, where the decls will continue to live in the
    // surrounding context.
    SmallVector<NamedDecl *, 0> DeclsInPrototype;
    if (getCurScope()->getFlags() & Scope::FunctionDeclarationScope &&
        !getLangOpts().CPlusPlus) {
      for (Decl *D : getCurScope()->decls()) {
        NamedDecl *ND = dyn_cast<NamedDecl>(D);
        if (!ND || isa<ParmVarDecl>(ND))
          continue;
        DeclsInPrototype.push_back(ND);
      }
    }
  
    // Remember that we parsed a function type, and remember the attributes.
    D.AddTypeInfo(DeclaratorChunk::getFunction(
                      HasProto, IsAmbiguous, LParenLoc, ParamInfo.data(),
                      ParamInfo.size(), EllipsisLoc, RParenLoc,
                      RefQualifierIsLValueRef, RefQualifierLoc,
                      /*MutableLoc=*/SourceLocation(),
                      ESpecType, ESpecRange, DynamicExceptions.data(),
                      DynamicExceptionRanges.data(), DynamicExceptions.size(),
                      NoexceptExpr.isUsable() ? NoexceptExpr.get() : nullptr,
                      ExceptionSpecTokens, DeclsInPrototype, StartLoc,
                      LocalEndLoc, D, TrailingReturnType, &DS),
                  std::move(FnAttrs), EndLoc);
  }
  
  /// ParseRefQualifier - Parses a member function ref-qualifier. Returns
  /// true if a ref-qualifier is found.
  bool Parser::ParseRefQualifier(bool &RefQualifierIsLValueRef,
                                 SourceLocation &RefQualifierLoc) {
    if (Tok.isOneOf(tok::amp, tok::ampamp)) {
      Diag(Tok, getLangOpts().CPlusPlus11 ?
           diag::warn_cxx98_compat_ref_qualifier :
           diag::ext_ref_qualifier);
  
      RefQualifierIsLValueRef = Tok.is(tok::amp);
      RefQualifierLoc = ConsumeToken();
      return true;
    }
    return false;
  }
  
  /// isFunctionDeclaratorIdentifierList - This parameter list may have an
  /// identifier list form for a K&R-style function:  void foo(a,b,c)
  ///
  /// Note that identifier-lists are only allowed for normal declarators, not for
  /// abstract-declarators.
  bool Parser::isFunctionDeclaratorIdentifierList() {
    return !getLangOpts().CPlusPlus
           && Tok.is(tok::identifier)
           && !TryAltiVecVectorToken()
           // K&R identifier lists can't have typedefs as identifiers, per C99
           // 6.7.5.3p11.
           && (TryAnnotateTypeOrScopeToken() || !Tok.is(tok::annot_typename))
           // Identifier lists follow a really simple grammar: the identifiers can
           // be followed *only* by a ", identifier" or ")".  However, K&R
           // identifier lists are really rare in the brave new modern world, and
           // it is very common for someone to typo a type in a non-K&R style
           // list.  If we are presented with something like: "void foo(intptr x,
           // float y)", we don't want to start parsing the function declarator as
           // though it is a K&R style declarator just because intptr is an
           // invalid type.
           //
           // To handle this, we check to see if the token after the first
           // identifier is a "," or ")".  Only then do we parse it as an
           // identifier list.
           && (!Tok.is(tok::eof) &&
               (NextToken().is(tok::comma) || NextToken().is(tok::r_paren)));
  }
  
  /// ParseFunctionDeclaratorIdentifierList - While parsing a function declarator
  /// we found a K&R-style identifier list instead of a typed parameter list.
  ///
  /// After returning, ParamInfo will hold the parsed parameters.
  ///
  ///       identifier-list: [C99 6.7.5]
  ///         identifier
  ///         identifier-list ',' identifier
  ///
  void Parser::ParseFunctionDeclaratorIdentifierList(
         Declarator &D,
         SmallVectorImpl<DeclaratorChunk::ParamInfo> &ParamInfo) {
    // If there was no identifier specified for the declarator, either we are in
    // an abstract-declarator, or we are in a parameter declarator which was found
    // to be abstract.  In abstract-declarators, identifier lists are not valid:
    // diagnose this.
    if (!D.getIdentifier())
      Diag(Tok, diag::ext_ident_list_in_param);
  
    // Maintain an efficient lookup of params we have seen so far.
    llvm::SmallSet<const IdentifierInfo*, 16> ParamsSoFar;
  
    do {
      // If this isn't an identifier, report the error and skip until ')'.
      if (Tok.isNot(tok::identifier)) {
        Diag(Tok, diag::err_expected) << tok::identifier;
        SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
        // Forget we parsed anything.
        ParamInfo.clear();
        return;
      }
  
      IdentifierInfo *ParmII = Tok.getIdentifierInfo();
  
      // Reject 'typedef int y; int test(x, y)', but continue parsing.
      if (Actions.getTypeName(*ParmII, Tok.getLocation(), getCurScope()))
        Diag(Tok, diag::err_unexpected_typedef_ident) << ParmII;
  
      // Verify that the argument identifier has not already been mentioned.
      if (!ParamsSoFar.insert(ParmII).second) {
        Diag(Tok, diag::err_param_redefinition) << ParmII;
      } else {
        // Remember this identifier in ParamInfo.
        ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
                                                       Tok.getLocation(),
                                                       nullptr));
      }
  
      // Eat the identifier.
      ConsumeToken();
      // The list continues if we see a comma.
    } while (TryConsumeToken(tok::comma));
  }
  
  /// ParseParameterDeclarationClause - Parse a (possibly empty) parameter-list
  /// after the opening parenthesis. This function will not parse a K&R-style
  /// identifier list.
  ///
  /// DeclContext is the context of the declarator being parsed.  If FirstArgAttrs
  /// is non-null, then the caller parsed those attributes immediately after the
  /// open paren - they should be considered to be part of the first parameter.
  ///
  /// After returning, ParamInfo will hold the parsed parameters. EllipsisLoc will
  /// be the location of the ellipsis, if any was parsed.
  ///
  ///       parameter-type-list: [C99 6.7.5]
  ///         parameter-list
  ///         parameter-list ',' '...'
  /// [C++]   parameter-list '...'
  ///
  ///       parameter-list: [C99 6.7.5]
  ///         parameter-declaration
  ///         parameter-list ',' parameter-declaration
  ///
  ///       parameter-declaration: [C99 6.7.5]
  ///         declaration-specifiers declarator
  /// [C++]   declaration-specifiers declarator '=' assignment-expression
  /// [C++11]                                       initializer-clause
  /// [GNU]   declaration-specifiers declarator attributes
  ///         declaration-specifiers abstract-declarator[opt]
  /// [C++]   declaration-specifiers abstract-declarator[opt]
  ///           '=' assignment-expression
  /// [GNU]   declaration-specifiers abstract-declarator[opt] attributes
  /// [C++11] attribute-specifier-seq parameter-declaration
  ///
  void Parser::ParseParameterDeclarationClause(
         DeclaratorContext DeclaratorContext,
         ParsedAttributes &FirstArgAttrs,
         SmallVectorImpl<DeclaratorChunk::ParamInfo> &ParamInfo,
         SourceLocation &EllipsisLoc) {
    do {
      // FIXME: Issue a diagnostic if we parsed an attribute-specifier-seq
      // before deciding this was a parameter-declaration-clause.
      if (TryConsumeToken(tok::ellipsis, EllipsisLoc))
        break;
  
      // Parse the declaration-specifiers.
      // Just use the ParsingDeclaration "scope" of the declarator.
      DeclSpec DS(AttrFactory);
  
      // Parse any C++11 attributes.
      MaybeParseCXX11Attributes(DS.getAttributes());
  
      // Skip any Microsoft attributes before a param.
      MaybeParseMicrosoftAttributes(DS.getAttributes());
  
      SourceLocation DSStart = Tok.getLocation();
  
      // If the caller parsed attributes for the first argument, add them now.
      // Take them so that we only apply the attributes to the first parameter.
      // FIXME: If we can leave the attributes in the token stream somehow, we can
      // get rid of a parameter (FirstArgAttrs) and this statement. It might be
      // too much hassle.
      DS.takeAttributesFrom(FirstArgAttrs);
  
      ParseDeclarationSpecifiers(DS);
  
  
      // Parse the declarator.  This is "PrototypeContext" or
      // "LambdaExprParameterContext", because we must accept either
      // 'declarator' or 'abstract-declarator' here.
      Declarator ParmDeclarator(
          DS, DeclaratorContext == DeclaratorContext::RequiresExprContext
                  ? DeclaratorContext::RequiresExprContext
                  : DeclaratorContext == DeclaratorContext::LambdaExprContext
                        ? DeclaratorContext::LambdaExprParameterContext
                        : DeclaratorContext::PrototypeContext);
      ParseDeclarator(ParmDeclarator);
  
      // Parse GNU attributes, if present.
      MaybeParseGNUAttributes(ParmDeclarator);
  
      if (Tok.is(tok::kw_requires)) {
        // User tried to define a requires clause in a parameter declaration,
        // which is surely not a function declaration.
        // void f(int (*g)(int, int) requires true);
        Diag(Tok,
             diag::err_requires_clause_on_declarator_not_declaring_a_function);
        ConsumeToken();
        Actions.CorrectDelayedTyposInExpr(ParseConstraintLogicalOrExpression());
      }
  
      // Remember this parsed parameter in ParamInfo.
      IdentifierInfo *ParmII = ParmDeclarator.getIdentifier();
  
      // DefArgToks is used when the parsing of default arguments needs
      // to be delayed.
      std::unique_ptr<CachedTokens> DefArgToks;
  
      // If no parameter was specified, verify that *something* was specified,
      // otherwise we have a missing type and identifier.
      if (DS.isEmpty() && ParmDeclarator.getIdentifier() == nullptr &&
          ParmDeclarator.getNumTypeObjects() == 0) {
        // Completely missing, emit error.
        Diag(DSStart, diag::err_missing_param);
      } else {
        // Otherwise, we have something.  Add it and let semantic analysis try
        // to grok it and add the result to the ParamInfo we are building.
  
        // Last chance to recover from a misplaced ellipsis in an attempted
        // parameter pack declaration.
        if (Tok.is(tok::ellipsis) &&
            (NextToken().isNot(tok::r_paren) ||
             (!ParmDeclarator.getEllipsisLoc().isValid() &&
              !Actions.isUnexpandedParameterPackPermitted())) &&
            Actions.containsUnexpandedParameterPacks(ParmDeclarator))
          DiagnoseMisplacedEllipsisInDeclarator(ConsumeToken(), ParmDeclarator);
  
        // Inform the actions module about the parameter declarator, so it gets
        // added to the current scope.
        Decl *Param = Actions.ActOnParamDeclarator(getCurScope(), ParmDeclarator);
        // Parse the default argument, if any. We parse the default
        // arguments in all dialects; the semantic analysis in
        // ActOnParamDefaultArgument will reject the default argument in
        // C.
        if (Tok.is(tok::equal)) {
          SourceLocation EqualLoc = Tok.getLocation();
  
          // Parse the default argument
          if (DeclaratorContext == DeclaratorContext::MemberContext) {
            // If we're inside a class definition, cache the tokens
            // corresponding to the default argument. We'll actually parse
            // them when we see the end of the class definition.
            DefArgToks.reset(new CachedTokens);
  
            SourceLocation ArgStartLoc = NextToken().getLocation();
            if (!ConsumeAndStoreInitializer(*DefArgToks, CIK_DefaultArgument)) {
              DefArgToks.reset();
              Actions.ActOnParamDefaultArgumentError(Param, EqualLoc);
            } else {
              Actions.ActOnParamUnparsedDefaultArgument(Param, EqualLoc,
                                                        ArgStartLoc);
            }
          } else {
            // Consume the '='.
            ConsumeToken();
  
            // The argument isn't actually potentially evaluated unless it is
            // used.
            EnterExpressionEvaluationContext Eval(
                Actions,
                Sema::ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed,
                Param);
  
            ExprResult DefArgResult;
            if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
              Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
              DefArgResult = ParseBraceInitializer();
            } else
              DefArgResult = ParseAssignmentExpression();
            DefArgResult = Actions.CorrectDelayedTyposInExpr(DefArgResult);
            if (DefArgResult.isInvalid()) {
              Actions.ActOnParamDefaultArgumentError(Param, EqualLoc);
              SkipUntil(tok::comma, tok::r_paren, StopAtSemi | StopBeforeMatch);
            } else {
              // Inform the actions module about the default argument
              Actions.ActOnParamDefaultArgument(Param, EqualLoc,
                                                DefArgResult.get());
            }
          }
        }
  
        ParamInfo.push_back(DeclaratorChunk::ParamInfo(ParmII,
                                            ParmDeclarator.getIdentifierLoc(),
                                            Param, std::move(DefArgToks)));
      }
  
      if (TryConsumeToken(tok::ellipsis, EllipsisLoc)) {
        if (!getLangOpts().CPlusPlus) {
          // We have ellipsis without a preceding ',', which is ill-formed
          // in C. Complain and provide the fix.
          Diag(EllipsisLoc, diag::err_missing_comma_before_ellipsis)
              << FixItHint::CreateInsertion(EllipsisLoc, ", ");
        } else if (ParmDeclarator.getEllipsisLoc().isValid() ||
                   Actions.containsUnexpandedParameterPacks(ParmDeclarator)) {
          // It looks like this was supposed to be a parameter pack. Warn and
          // point out where the ellipsis should have gone.
          SourceLocation ParmEllipsis = ParmDeclarator.getEllipsisLoc();
          Diag(EllipsisLoc, diag::warn_misplaced_ellipsis_vararg)
            << ParmEllipsis.isValid() << ParmEllipsis;
          if (ParmEllipsis.isValid()) {
            Diag(ParmEllipsis,
                 diag::note_misplaced_ellipsis_vararg_existing_ellipsis);
          } else {
            Diag(ParmDeclarator.getIdentifierLoc(),
                 diag::note_misplaced_ellipsis_vararg_add_ellipsis)
              << FixItHint::CreateInsertion(ParmDeclarator.getIdentifierLoc(),
                                            "...")
              << !ParmDeclarator.hasName();
          }
          Diag(EllipsisLoc, diag::note_misplaced_ellipsis_vararg_add_comma)
            << FixItHint::CreateInsertion(EllipsisLoc, ", ");
        }
  
        // We can't have any more parameters after an ellipsis.
        break;
      }
  
      // If the next token is a comma, consume it and keep reading arguments.
    } while (TryConsumeToken(tok::comma));
  }
  
  /// [C90]   direct-declarator '[' constant-expression[opt] ']'
  /// [C99]   direct-declarator '[' type-qual-list[opt] assignment-expr[opt] ']'
  /// [C99]   direct-declarator '[' 'static' type-qual-list[opt] assign-expr ']'
  /// [C99]   direct-declarator '[' type-qual-list 'static' assignment-expr ']'
  /// [C99]   direct-declarator '[' type-qual-list[opt] '*' ']'
  /// [C++11] direct-declarator '[' constant-expression[opt] ']'
  ///                           attribute-specifier-seq[opt]
  void Parser::ParseBracketDeclarator(Declarator &D) {
    if (CheckProhibitedCXX11Attribute())
      return;
  
    BalancedDelimiterTracker T(*this, tok::l_square);
    T.consumeOpen();
  
    // C array syntax has many features, but by-far the most common is [] and [4].
    // This code does a fast path to handle some of the most obvious cases.
    if (Tok.getKind() == tok::r_square) {
      T.consumeClose();
      ParsedAttributes attrs(AttrFactory);
      MaybeParseCXX11Attributes(attrs);
  
      // Remember that we parsed the empty array type.
      D.AddTypeInfo(DeclaratorChunk::getArray(0, false, false, nullptr,
                                              T.getOpenLocation(),
                                              T.getCloseLocation()),
                    std::move(attrs), T.getCloseLocation());
      return;
    } else if (Tok.getKind() == tok::numeric_constant &&
               GetLookAheadToken(1).is(tok::r_square)) {
      // [4] is very common.  Parse the numeric constant expression.
      ExprResult ExprRes(Actions.ActOnNumericConstant(Tok, getCurScope()));
      ConsumeToken();
  
      T.consumeClose();
      ParsedAttributes attrs(AttrFactory);
      MaybeParseCXX11Attributes(attrs);
  
      // Remember that we parsed a array type, and remember its features.
      D.AddTypeInfo(DeclaratorChunk::getArray(0, false, false, ExprRes.get(),
                                              T.getOpenLocation(),
                                              T.getCloseLocation()),
                    std::move(attrs), T.getCloseLocation());
      return;
    } else if (Tok.getKind() == tok::code_completion) {
      Actions.CodeCompleteBracketDeclarator(getCurScope());
      return cutOffParsing();
    }
  
    // If valid, this location is the position where we read the 'static' keyword.
    SourceLocation StaticLoc;
    TryConsumeToken(tok::kw_static, StaticLoc);
  
    // If there is a type-qualifier-list, read it now.
    // Type qualifiers in an array subscript are a C99 feature.
    DeclSpec DS(AttrFactory);
    ParseTypeQualifierListOpt(DS, AR_CXX11AttributesParsed);
  
    // If we haven't already read 'static', check to see if there is one after the
    // type-qualifier-list.
    if (!StaticLoc.isValid())
      TryConsumeToken(tok::kw_static, StaticLoc);
  
    // Handle "direct-declarator [ type-qual-list[opt] * ]".
    bool isStar = false;
    ExprResult NumElements;
  
    // Handle the case where we have '[*]' as the array size.  However, a leading
    // star could be the start of an expression, for example 'X[*p + 4]'.  Verify
    // the token after the star is a ']'.  Since stars in arrays are
    // infrequent, use of lookahead is not costly here.
    if (Tok.is(tok::star) && GetLookAheadToken(1).is(tok::r_square)) {
      ConsumeToken();  // Eat the '*'.
  
      if (StaticLoc.isValid()) {
        Diag(StaticLoc, diag::err_unspecified_vla_size_with_static);
        StaticLoc = SourceLocation();  // Drop the static.
      }
      isStar = true;
    } else if (Tok.isNot(tok::r_square)) {
      // Note, in C89, this production uses the constant-expr production instead
      // of assignment-expr.  The only difference is that assignment-expr allows
      // things like '=' and '*='.  Sema rejects these in C89 mode because they
      // are not i-c-e's, so we don't need to distinguish between the two here.
  
      // Parse the constant-expression or assignment-expression now (depending
      // on dialect).
      if (getLangOpts().CPlusPlus) {
        NumElements = ParseConstantExpression();
      } else {
        EnterExpressionEvaluationContext Unevaluated(
            Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
        NumElements =
            Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression());
      }
    } else {
      if (StaticLoc.isValid()) {
        Diag(StaticLoc, diag::err_unspecified_size_with_static);
        StaticLoc = SourceLocation();  // Drop the static.
      }
    }
  
    // If there was an error parsing the assignment-expression, recover.
    if (NumElements.isInvalid()) {
      D.setInvalidType(true);
      // If the expression was invalid, skip it.
      SkipUntil(tok::r_square, StopAtSemi);
      return;
    }
  
    T.consumeClose();
  
    MaybeParseCXX11Attributes(DS.getAttributes());
  
    // Remember that we parsed a array type, and remember its features.
    D.AddTypeInfo(
        DeclaratorChunk::getArray(DS.getTypeQualifiers(), StaticLoc.isValid(),
                                  isStar, NumElements.get(), T.getOpenLocation(),
                                  T.getCloseLocation()),
        std::move(DS.getAttributes()), T.getCloseLocation());
  }
  
  /// Diagnose brackets before an identifier.
  void Parser::ParseMisplacedBracketDeclarator(Declarator &D) {
    assert(Tok.is(tok::l_square) && "Missing opening bracket");
    assert(!D.mayOmitIdentifier() && "Declarator cannot omit identifier");
  
    SourceLocation StartBracketLoc = Tok.getLocation();
    Declarator TempDeclarator(D.getDeclSpec(), D.getContext());
  
    while (Tok.is(tok::l_square)) {
      ParseBracketDeclarator(TempDeclarator);
    }
  
    // Stuff the location of the start of the brackets into the Declarator.
    // The diagnostics from ParseDirectDeclarator will make more sense if
    // they use this location instead.
    if (Tok.is(tok::semi))
      D.getName().EndLocation = StartBracketLoc;
  
    SourceLocation SuggestParenLoc = Tok.getLocation();
  
    // Now that the brackets are removed, try parsing the declarator again.
    ParseDeclaratorInternal(D, &Parser::ParseDirectDeclarator);
  
    // Something went wrong parsing the brackets, in which case,
    // ParseBracketDeclarator has emitted an error, and we don't need to emit
    // one here.
    if (TempDeclarator.getNumTypeObjects() == 0)
      return;
  
    // Determine if parens will need to be suggested in the diagnostic.
    bool NeedParens = false;
    if (D.getNumTypeObjects() != 0) {
      switch (D.getTypeObject(D.getNumTypeObjects() - 1).Kind) {
      case DeclaratorChunk::Pointer:
      case DeclaratorChunk::Reference:
      case DeclaratorChunk::BlockPointer:
      case DeclaratorChunk::MemberPointer:
      case DeclaratorChunk::Pipe:
        NeedParens = true;
        break;
      case DeclaratorChunk::Array:
      case DeclaratorChunk::Function:
      case DeclaratorChunk::Paren:
        break;
      }
    }
  
    if (NeedParens) {
      // Create a DeclaratorChunk for the inserted parens.
      SourceLocation EndLoc = PP.getLocForEndOfToken(D.getEndLoc());
      D.AddTypeInfo(DeclaratorChunk::getParen(SuggestParenLoc, EndLoc),
                    SourceLocation());
    }
  
    // Adding back the bracket info to the end of the Declarator.
    for (unsigned i = 0, e = TempDeclarator.getNumTypeObjects(); i < e; ++i) {
      const DeclaratorChunk &Chunk = TempDeclarator.getTypeObject(i);
      D.AddTypeInfo(Chunk, SourceLocation());
    }
  
    // The missing identifier would have been diagnosed in ParseDirectDeclarator.
    // If parentheses are required, always suggest them.
    if (!D.getIdentifier() && !NeedParens)
      return;
  
    SourceLocation EndBracketLoc = TempDeclarator.getEndLoc();
  
    // Generate the move bracket error message.
    SourceRange BracketRange(StartBracketLoc, EndBracketLoc);
    SourceLocation EndLoc = PP.getLocForEndOfToken(D.getEndLoc());
  
    if (NeedParens) {
      Diag(EndLoc, diag::err_brackets_go_after_unqualified_id)
          << getLangOpts().CPlusPlus
          << FixItHint::CreateInsertion(SuggestParenLoc, "(")
          << FixItHint::CreateInsertion(EndLoc, ")")
          << FixItHint::CreateInsertionFromRange(
                 EndLoc, CharSourceRange(BracketRange, true))
          << FixItHint::CreateRemoval(BracketRange);
    } else {
      Diag(EndLoc, diag::err_brackets_go_after_unqualified_id)
          << getLangOpts().CPlusPlus
          << FixItHint::CreateInsertionFromRange(
                 EndLoc, CharSourceRange(BracketRange, true))
          << FixItHint::CreateRemoval(BracketRange);
    }
  }
  
  /// [GNU]   typeof-specifier:
  ///           typeof ( expressions )
  ///           typeof ( type-name )
  /// [GNU/C++] typeof unary-expression
  ///
  void Parser::ParseTypeofSpecifier(DeclSpec &DS) {
    assert(Tok.is(tok::kw_typeof) && "Not a typeof specifier");
    Token OpTok = Tok;
    SourceLocation StartLoc = ConsumeToken();
  
    const bool hasParens = Tok.is(tok::l_paren);
  
    EnterExpressionEvaluationContext Unevaluated(
        Actions, Sema::ExpressionEvaluationContext::Unevaluated,
        Sema::ReuseLambdaContextDecl);
  
    bool isCastExpr;
    ParsedType CastTy;
    SourceRange CastRange;
    ExprResult Operand = Actions.CorrectDelayedTyposInExpr(
        ParseExprAfterUnaryExprOrTypeTrait(OpTok, isCastExpr, CastTy, CastRange));
    if (hasParens)
      DS.setTypeofParensRange(CastRange);
  
    if (CastRange.getEnd().isInvalid())
      // FIXME: Not accurate, the range gets one token more than it should.
      DS.SetRangeEnd(Tok.getLocation());
    else
      DS.SetRangeEnd(CastRange.getEnd());
  
    if (isCastExpr) {
      if (!CastTy) {
        DS.SetTypeSpecError();
        return;
      }
  
      const char *PrevSpec = nullptr;
      unsigned DiagID;
      // Check for duplicate type specifiers (e.g. "int typeof(int)").
      if (DS.SetTypeSpecType(DeclSpec::TST_typeofType, StartLoc, PrevSpec,
                             DiagID, CastTy,
                             Actions.getASTContext().getPrintingPolicy()))
        Diag(StartLoc, DiagID) << PrevSpec;
      return;
    }
  
    // If we get here, the operand to the typeof was an expression.
    if (Operand.isInvalid()) {
      DS.SetTypeSpecError();
      return;
    }
  
    // We might need to transform the operand if it is potentially evaluated.
    Operand = Actions.HandleExprEvaluationContextForTypeof(Operand.get());
    if (Operand.isInvalid()) {
      DS.SetTypeSpecError();
      return;
    }
  
    const char *PrevSpec = nullptr;
    unsigned DiagID;
    // Check for duplicate type specifiers (e.g. "int typeof(int)").
    if (DS.SetTypeSpecType(DeclSpec::TST_typeofExpr, StartLoc, PrevSpec,
                           DiagID, Operand.get(),
                           Actions.getASTContext().getPrintingPolicy()))
      Diag(StartLoc, DiagID) << PrevSpec;
  }
  
  /// [C11]   atomic-specifier:
  ///           _Atomic ( type-name )
  ///
  void Parser::ParseAtomicSpecifier(DeclSpec &DS) {
    assert(Tok.is(tok::kw__Atomic) && NextToken().is(tok::l_paren) &&
           "Not an atomic specifier");
  
    SourceLocation StartLoc = ConsumeToken();
    BalancedDelimiterTracker T(*this, tok::l_paren);
    if (T.consumeOpen())
      return;
  
    TypeResult Result = ParseTypeName();
    if (Result.isInvalid()) {
      SkipUntil(tok::r_paren, StopAtSemi);
      return;
    }
  
    // Match the ')'
    T.consumeClose();
  
    if (T.getCloseLocation().isInvalid())
      return;
  
    DS.setTypeofParensRange(T.getRange());
    DS.SetRangeEnd(T.getCloseLocation());
  
    const char *PrevSpec = nullptr;
    unsigned DiagID;
    if (DS.SetTypeSpecType(DeclSpec::TST_atomic, StartLoc, PrevSpec,
                           DiagID, Result.get(),
                           Actions.getASTContext().getPrintingPolicy()))
      Diag(StartLoc, DiagID) << PrevSpec;
  }
  
  /// TryAltiVecVectorTokenOutOfLine - Out of line body that should only be called
  /// from TryAltiVecVectorToken.
  bool Parser::TryAltiVecVectorTokenOutOfLine() {
    Token Next = NextToken();
    switch (Next.getKind()) {
    default: return false;
    case tok::kw_short:
    case tok::kw_long:
    case tok::kw_signed:
    case tok::kw_unsigned:
    case tok::kw_void:
    case tok::kw_char:
    case tok::kw_int:
    case tok::kw_float:
    case tok::kw_double:
    case tok::kw_bool:
    case tok::kw___bool:
    case tok::kw___pixel:
      Tok.setKind(tok::kw___vector);
      return true;
    case tok::identifier:
      if (Next.getIdentifierInfo() == Ident_pixel) {
        Tok.setKind(tok::kw___vector);
        return true;
      }
      if (Next.getIdentifierInfo() == Ident_bool) {
        Tok.setKind(tok::kw___vector);
        return true;
      }
      return false;
    }
  }
  
  bool Parser::TryAltiVecTokenOutOfLine(DeclSpec &DS, SourceLocation Loc,
                                        const char *&PrevSpec, unsigned &DiagID,
                                        bool &isInvalid) {
    const PrintingPolicy &Policy = Actions.getASTContext().getPrintingPolicy();
    if (Tok.getIdentifierInfo() == Ident_vector) {
      Token Next = NextToken();
      switch (Next.getKind()) {
      case tok::kw_short:
      case tok::kw_long:
      case tok::kw_signed:
      case tok::kw_unsigned:
      case tok::kw_void:
      case tok::kw_char:
      case tok::kw_int:
      case tok::kw_float:
      case tok::kw_double:
      case tok::kw_bool:
      case tok::kw___bool:
      case tok::kw___pixel:
        isInvalid = DS.SetTypeAltiVecVector(true, Loc, PrevSpec, DiagID, Policy);
        return true;
      case tok::identifier:
        if (Next.getIdentifierInfo() == Ident_pixel) {
          isInvalid = DS.SetTypeAltiVecVector(true, Loc, PrevSpec, DiagID,Policy);
          return true;
        }
        if (Next.getIdentifierInfo() == Ident_bool) {
          isInvalid = DS.SetTypeAltiVecVector(true, Loc, PrevSpec, DiagID,Policy);
          return true;
        }
        break;
      default:
        break;
      }
    } else if ((Tok.getIdentifierInfo() == Ident_pixel) &&
               DS.isTypeAltiVecVector()) {
      isInvalid = DS.SetTypeAltiVecPixel(true, Loc, PrevSpec, DiagID, Policy);
      return true;
    } else if ((Tok.getIdentifierInfo() == Ident_bool) &&
               DS.isTypeAltiVecVector()) {
      isInvalid = DS.SetTypeAltiVecBool(true, Loc, PrevSpec, DiagID, Policy);
      return true;
    }
    return false;
  }
  