--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/lib/Parse/ParseExpr.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,3458 @@
+//===--- ParseExpr.cpp - Expression Parsing -------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// Provides the Expression parsing implementation.
+///
+/// Expressions in C99 basically consist of a bunch of binary operators with
+/// unary operators and other random stuff at the leaves.
+///
+/// In the C99 grammar, these unary operators bind tightest and are represented
+/// as the 'cast-expression' production.  Everything else is either a binary
+/// operator (e.g. '/') or a ternary operator ("?:").  The unary leaves are
+/// handled by ParseCastExpression, the higher level pieces are handled by
+/// ParseBinaryExpression.
+///
+//===----------------------------------------------------------------------===//
+
+#include "clang/Parse/Parser.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/Basic/PrettyStackTrace.h"
+#include "clang/Parse/RAIIObjectsForParser.h"
+#include "clang/Sema/DeclSpec.h"
+#include "clang/Sema/ParsedTemplate.h"
+#include "clang/Sema/Scope.h"
+#include "clang/Sema/TypoCorrection.h"
+#include "llvm/ADT/SmallVector.h"
+using namespace clang;
+
+/// Simple precedence-based parser for binary/ternary operators.
+///
+/// Note: we diverge from the C99 grammar when parsing the assignment-expression
+/// production.  C99 specifies that the LHS of an assignment operator should be
+/// parsed as a unary-expression, but consistency dictates that it be a
+/// conditional-expession.  In practice, the important thing here is that the
+/// LHS of an assignment has to be an l-value, which productions between
+/// unary-expression and conditional-expression don't produce.  Because we want
+/// consistency, we parse the LHS as a conditional-expression, then check for
+/// l-value-ness in semantic analysis stages.
+///
+/// \verbatim
+///       pm-expression: [C++ 5.5]
+///         cast-expression
+///         pm-expression '.*' cast-expression
+///         pm-expression '->*' cast-expression
+///
+///       multiplicative-expression: [C99 6.5.5]
+///     Note: in C++, apply pm-expression instead of cast-expression
+///         cast-expression
+///         multiplicative-expression '*' cast-expression
+///         multiplicative-expression '/' cast-expression
+///         multiplicative-expression '%' cast-expression
+///
+///       additive-expression: [C99 6.5.6]
+///         multiplicative-expression
+///         additive-expression '+' multiplicative-expression
+///         additive-expression '-' multiplicative-expression
+///
+///       shift-expression: [C99 6.5.7]
+///         additive-expression
+///         shift-expression '<<' additive-expression
+///         shift-expression '>>' additive-expression
+///
+///       compare-expression: [C++20 expr.spaceship]
+///         shift-expression
+///         compare-expression '<=>' shift-expression
+///
+///       relational-expression: [C99 6.5.8]
+///         compare-expression
+///         relational-expression '<' compare-expression
+///         relational-expression '>' compare-expression
+///         relational-expression '<=' compare-expression
+///         relational-expression '>=' compare-expression
+///
+///       equality-expression: [C99 6.5.9]
+///         relational-expression
+///         equality-expression '==' relational-expression
+///         equality-expression '!=' relational-expression
+///
+///       AND-expression: [C99 6.5.10]
+///         equality-expression
+///         AND-expression '&' equality-expression
+///
+///       exclusive-OR-expression: [C99 6.5.11]
+///         AND-expression
+///         exclusive-OR-expression '^' AND-expression
+///
+///       inclusive-OR-expression: [C99 6.5.12]
+///         exclusive-OR-expression
+///         inclusive-OR-expression '|' exclusive-OR-expression
+///
+///       logical-AND-expression: [C99 6.5.13]
+///         inclusive-OR-expression
+///         logical-AND-expression '&&' inclusive-OR-expression
+///
+///       logical-OR-expression: [C99 6.5.14]
+///         logical-AND-expression
+///         logical-OR-expression '||' logical-AND-expression
+///
+///       conditional-expression: [C99 6.5.15]
+///         logical-OR-expression
+///         logical-OR-expression '?' expression ':' conditional-expression
+/// [GNU]   logical-OR-expression '?' ':' conditional-expression
+/// [C++] the third operand is an assignment-expression
+///
+///       assignment-expression: [C99 6.5.16]
+///         conditional-expression
+///         unary-expression assignment-operator assignment-expression
+/// [C++]   throw-expression [C++ 15]
+///
+///       assignment-operator: one of
+///         = *= /= %= += -= <<= >>= &= ^= |=
+///
+///       expression: [C99 6.5.17]
+///         assignment-expression ...[opt]
+///         expression ',' assignment-expression ...[opt]
+/// \endverbatim
+ExprResult Parser::ParseExpression(TypeCastState isTypeCast) {
+  ExprResult LHS(ParseAssignmentExpression(isTypeCast));
+  return ParseRHSOfBinaryExpression(LHS, prec::Comma);
+}
+
+/// This routine is called when the '@' is seen and consumed.
+/// Current token is an Identifier and is not a 'try'. This
+/// routine is necessary to disambiguate \@try-statement from,
+/// for example, \@encode-expression.
+///
+ExprResult
+Parser::ParseExpressionWithLeadingAt(SourceLocation AtLoc) {
+  ExprResult LHS(ParseObjCAtExpression(AtLoc));
+  return ParseRHSOfBinaryExpression(LHS, prec::Comma);
+}
+
+/// This routine is called when a leading '__extension__' is seen and
+/// consumed.  This is necessary because the token gets consumed in the
+/// process of disambiguating between an expression and a declaration.
+ExprResult
+Parser::ParseExpressionWithLeadingExtension(SourceLocation ExtLoc) {
+  ExprResult LHS(true);
+  {
+    // Silence extension warnings in the sub-expression
+    ExtensionRAIIObject O(Diags);
+
+    LHS = ParseCastExpression(AnyCastExpr);
+  }
+
+  if (!LHS.isInvalid())
+    LHS = Actions.ActOnUnaryOp(getCurScope(), ExtLoc, tok::kw___extension__,
+                               LHS.get());
+
+  return ParseRHSOfBinaryExpression(LHS, prec::Comma);
+}
+
+/// Parse an expr that doesn't include (top-level) commas.
+ExprResult Parser::ParseAssignmentExpression(TypeCastState isTypeCast) {
+  if (Tok.is(tok::code_completion)) {
+    Actions.CodeCompleteExpression(getCurScope(),
+                                   PreferredType.get(Tok.getLocation()));
+    cutOffParsing();
+    return ExprError();
+  }
+
+  if (Tok.is(tok::kw_throw))
+    return ParseThrowExpression();
+  if (Tok.is(tok::kw_co_yield))
+    return ParseCoyieldExpression();
+
+  ExprResult LHS = ParseCastExpression(AnyCastExpr,
+                                       /*isAddressOfOperand=*/false,
+                                       isTypeCast);
+  return ParseRHSOfBinaryExpression(LHS, prec::Assignment);
+}
+
+/// Parse an assignment expression where part of an Objective-C message
+/// send has already been parsed.
+///
+/// In this case \p LBracLoc indicates the location of the '[' of the message
+/// send, and either \p ReceiverName or \p ReceiverExpr is non-null indicating
+/// the receiver of the message.
+///
+/// Since this handles full assignment-expression's, it handles postfix
+/// expressions and other binary operators for these expressions as well.
+ExprResult
+Parser::ParseAssignmentExprWithObjCMessageExprStart(SourceLocation LBracLoc,
+                                                    SourceLocation SuperLoc,
+                                                    ParsedType ReceiverType,
+                                                    Expr *ReceiverExpr) {
+  ExprResult R
+    = ParseObjCMessageExpressionBody(LBracLoc, SuperLoc,
+                                     ReceiverType, ReceiverExpr);
+  R = ParsePostfixExpressionSuffix(R);
+  return ParseRHSOfBinaryExpression(R, prec::Assignment);
+}
+
+ExprResult
+Parser::ParseConstantExpressionInExprEvalContext(TypeCastState isTypeCast) {
+  assert(Actions.ExprEvalContexts.back().Context ==
+             Sema::ExpressionEvaluationContext::ConstantEvaluated &&
+         "Call this function only if your ExpressionEvaluationContext is "
+         "already ConstantEvaluated");
+  ExprResult LHS(ParseCastExpression(AnyCastExpr, false, isTypeCast));
+  ExprResult Res(ParseRHSOfBinaryExpression(LHS, prec::Conditional));
+  return Actions.ActOnConstantExpression(Res);
+}
+
+ExprResult Parser::ParseConstantExpression(TypeCastState isTypeCast) {
+  // C++03 [basic.def.odr]p2:
+  //   An expression is potentially evaluated unless it appears where an
+  //   integral constant expression is required (see 5.19) [...].
+  // C++98 and C++11 have no such rule, but this is only a defect in C++98.
+  EnterExpressionEvaluationContext ConstantEvaluated(
+      Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
+  return ParseConstantExpressionInExprEvalContext(isTypeCast);
+}
+
+ExprResult Parser::ParseCaseExpression(SourceLocation CaseLoc) {
+  EnterExpressionEvaluationContext ConstantEvaluated(
+      Actions, Sema::ExpressionEvaluationContext::ConstantEvaluated);
+  ExprResult LHS(ParseCastExpression(AnyCastExpr, false, NotTypeCast));
+  ExprResult Res(ParseRHSOfBinaryExpression(LHS, prec::Conditional));
+  return Actions.ActOnCaseExpr(CaseLoc, Res);
+}
+
+/// Parse a constraint-expression.
+///
+/// \verbatim
+///       constraint-expression: C++2a[temp.constr.decl]p1
+///         logical-or-expression
+/// \endverbatim
+ExprResult Parser::ParseConstraintExpression() {
+  EnterExpressionEvaluationContext ConstantEvaluated(
+      Actions, Sema::ExpressionEvaluationContext::Unevaluated);
+  ExprResult LHS(ParseCastExpression(AnyCastExpr));
+  ExprResult Res(ParseRHSOfBinaryExpression(LHS, prec::LogicalOr));
+  if (Res.isUsable() && !Actions.CheckConstraintExpression(Res.get())) {
+    Actions.CorrectDelayedTyposInExpr(Res);
+    return ExprError();
+  }
+  return Res;
+}
+
+/// \brief Parse a constraint-logical-and-expression.
+///
+/// \verbatim
+///       C++2a[temp.constr.decl]p1
+///       constraint-logical-and-expression:
+///         primary-expression
+///         constraint-logical-and-expression '&&' primary-expression
+///
+/// \endverbatim
+ExprResult
+Parser::ParseConstraintLogicalAndExpression(bool IsTrailingRequiresClause) {
+  EnterExpressionEvaluationContext ConstantEvaluated(
+      Actions, Sema::ExpressionEvaluationContext::Unevaluated);
+  bool NotPrimaryExpression = false;
+  auto ParsePrimary = [&] () {
+    ExprResult E = ParseCastExpression(PrimaryExprOnly,
+                                       /*isAddressOfOperand=*/false,
+                                       /*isTypeCast=*/NotTypeCast,
+                                       /*isVectorLiteral=*/false,
+                                       &NotPrimaryExpression);
+    if (E.isInvalid())
+      return ExprError();
+    auto RecoverFromNonPrimary = [&] (ExprResult E, bool Note) {
+        E = ParsePostfixExpressionSuffix(E);
+        // Use InclusiveOr, the precedence just after '&&' to not parse the
+        // next arguments to the logical and.
+        E = ParseRHSOfBinaryExpression(E, prec::InclusiveOr);
+        if (!E.isInvalid())
+          Diag(E.get()->getExprLoc(),
+               Note
+               ? diag::note_unparenthesized_non_primary_expr_in_requires_clause
+               : diag::err_unparenthesized_non_primary_expr_in_requires_clause)
+               << FixItHint::CreateInsertion(E.get()->getBeginLoc(), "(")
+               << FixItHint::CreateInsertion(
+                   PP.getLocForEndOfToken(E.get()->getEndLoc()), ")")
+               << E.get()->getSourceRange();
+        return E;
+    };
+
+    if (NotPrimaryExpression ||
+        // Check if the following tokens must be a part of a non-primary
+        // expression
+        getBinOpPrecedence(Tok.getKind(), GreaterThanIsOperator,
+                           /*CPlusPlus11=*/true) > prec::LogicalAnd ||
+        // Postfix operators other than '(' (which will be checked for in
+        // CheckConstraintExpression).
+        Tok.isOneOf(tok::period, tok::plusplus, tok::minusminus) ||
+        (Tok.is(tok::l_square) && !NextToken().is(tok::l_square))) {
+      E = RecoverFromNonPrimary(E, /*Note=*/false);
+      if (E.isInvalid())
+        return ExprError();
+      NotPrimaryExpression = false;
+    }
+    bool PossibleNonPrimary;
+    bool IsConstraintExpr =
+        Actions.CheckConstraintExpression(E.get(), Tok, &PossibleNonPrimary,
+                                          IsTrailingRequiresClause);
+    if (!IsConstraintExpr || PossibleNonPrimary) {
+      // Atomic constraint might be an unparenthesized non-primary expression
+      // (such as a binary operator), in which case we might get here (e.g. in
+      // 'requires 0 + 1 && true' we would now be at '+', and parse and ignore
+      // the rest of the addition expression). Try to parse the rest of it here.
+      if (PossibleNonPrimary)
+        E = RecoverFromNonPrimary(E, /*Note=*/!IsConstraintExpr);
+      Actions.CorrectDelayedTyposInExpr(E);
+      return ExprError();
+    }
+    return E;
+  };
+  ExprResult LHS = ParsePrimary();
+  if (LHS.isInvalid())
+    return ExprError();
+  while (Tok.is(tok::ampamp)) {
+    SourceLocation LogicalAndLoc = ConsumeToken();
+    ExprResult RHS = ParsePrimary();
+    if (RHS.isInvalid()) {
+      Actions.CorrectDelayedTyposInExpr(LHS);
+      return ExprError();
+    }
+    ExprResult Op = Actions.ActOnBinOp(getCurScope(), LogicalAndLoc,
+                                       tok::ampamp, LHS.get(), RHS.get());
+    if (!Op.isUsable()) {
+      Actions.CorrectDelayedTyposInExpr(RHS);
+      Actions.CorrectDelayedTyposInExpr(LHS);
+      return ExprError();
+    }
+    LHS = Op;
+  }
+  return LHS;
+}
+
+/// \brief Parse a constraint-logical-or-expression.
+///
+/// \verbatim
+///       C++2a[temp.constr.decl]p1
+///       constraint-logical-or-expression:
+///         constraint-logical-and-expression
+///         constraint-logical-or-expression '||'
+///             constraint-logical-and-expression
+///
+/// \endverbatim
+ExprResult
+Parser::ParseConstraintLogicalOrExpression(bool IsTrailingRequiresClause) {
+  ExprResult LHS(ParseConstraintLogicalAndExpression(IsTrailingRequiresClause));
+  if (!LHS.isUsable())
+    return ExprError();
+  while (Tok.is(tok::pipepipe)) {
+    SourceLocation LogicalOrLoc = ConsumeToken();
+    ExprResult RHS =
+        ParseConstraintLogicalAndExpression(IsTrailingRequiresClause);
+    if (!RHS.isUsable()) {
+      Actions.CorrectDelayedTyposInExpr(LHS);
+      return ExprError();
+    }
+    ExprResult Op = Actions.ActOnBinOp(getCurScope(), LogicalOrLoc,
+                                       tok::pipepipe, LHS.get(), RHS.get());
+    if (!Op.isUsable()) {
+      Actions.CorrectDelayedTyposInExpr(RHS);
+      Actions.CorrectDelayedTyposInExpr(LHS);
+      return ExprError();
+    }
+    LHS = Op;
+  }
+  return LHS;
+}
+
+bool Parser::isNotExpressionStart() {
+  tok::TokenKind K = Tok.getKind();
+  if (K == tok::l_brace || K == tok::r_brace  ||
+      K == tok::kw_for  || K == tok::kw_while ||
+      K == tok::kw_if   || K == tok::kw_else  ||
+      K == tok::kw_goto || K == tok::kw_try)
+    return true;
+  // If this is a decl-specifier, we can't be at the start of an expression.
+  return isKnownToBeDeclarationSpecifier();
+}
+
+bool Parser::isFoldOperator(prec::Level Level) const {
+  return Level > prec::Unknown && Level != prec::Conditional &&
+         Level != prec::Spaceship;
+}
+
+bool Parser::isFoldOperator(tok::TokenKind Kind) const {
+  return isFoldOperator(getBinOpPrecedence(Kind, GreaterThanIsOperator, true));
+}
+
+/// Parse a binary expression that starts with \p LHS and has a
+/// precedence of at least \p MinPrec.
+ExprResult
+Parser::ParseRHSOfBinaryExpression(ExprResult LHS, prec::Level MinPrec) {
+  prec::Level NextTokPrec = getBinOpPrecedence(Tok.getKind(),
+                                               GreaterThanIsOperator,
+                                               getLangOpts().CPlusPlus11);
+  SourceLocation ColonLoc;
+
+  auto SavedType = PreferredType;
+  while (1) {
+    // Every iteration may rely on a preferred type for the whole expression.
+    PreferredType = SavedType;
+    // If this token has a lower precedence than we are allowed to parse (e.g.
+    // because we are called recursively, or because the token is not a binop),
+    // then we are done!
+    if (NextTokPrec < MinPrec)
+      return LHS;
+
+    // Consume the operator, saving the operator token for error reporting.
+    Token OpToken = Tok;
+    ConsumeToken();
+
+    if (OpToken.is(tok::caretcaret)) {
+      return ExprError(Diag(Tok, diag::err_opencl_logical_exclusive_or));
+    }
+
+    // If we're potentially in a template-id, we may now be able to determine
+    // whether we're actually in one or not.
+    if (OpToken.isOneOf(tok::comma, tok::greater, tok::greatergreater,
+                        tok::greatergreatergreater) &&
+        checkPotentialAngleBracketDelimiter(OpToken))
+      return ExprError();
+
+    // Bail out when encountering a comma followed by a token which can't
+    // possibly be the start of an expression. For instance:
+    //   int f() { return 1, }
+    // We can't do this before consuming the comma, because
+    // isNotExpressionStart() looks at the token stream.
+    if (OpToken.is(tok::comma) && isNotExpressionStart()) {
+      PP.EnterToken(Tok, /*IsReinject*/true);
+      Tok = OpToken;
+      return LHS;
+    }
+
+    // If the next token is an ellipsis, then this is a fold-expression. Leave
+    // it alone so we can handle it in the paren expression.
+    if (isFoldOperator(NextTokPrec) && Tok.is(tok::ellipsis)) {
+      // FIXME: We can't check this via lookahead before we consume the token
+      // because that tickles a lexer bug.
+      PP.EnterToken(Tok, /*IsReinject*/true);
+      Tok = OpToken;
+      return LHS;
+    }
+
+    // In Objective-C++, alternative operator tokens can be used as keyword args
+    // in message expressions. Unconsume the token so that it can reinterpreted
+    // as an identifier in ParseObjCMessageExpressionBody. i.e., we support:
+    //   [foo meth:0 and:0];
+    //   [foo not_eq];
+    if (getLangOpts().ObjC && getLangOpts().CPlusPlus &&
+        Tok.isOneOf(tok::colon, tok::r_square) &&
+        OpToken.getIdentifierInfo() != nullptr) {
+      PP.EnterToken(Tok, /*IsReinject*/true);
+      Tok = OpToken;
+      return LHS;
+    }
+
+    // Special case handling for the ternary operator.
+    ExprResult TernaryMiddle(true);
+    if (NextTokPrec == prec::Conditional) {
+      if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
+        // Parse a braced-init-list here for error recovery purposes.
+        SourceLocation BraceLoc = Tok.getLocation();
+        TernaryMiddle = ParseBraceInitializer();
+        if (!TernaryMiddle.isInvalid()) {
+          Diag(BraceLoc, diag::err_init_list_bin_op)
+              << /*RHS*/ 1 << PP.getSpelling(OpToken)
+              << Actions.getExprRange(TernaryMiddle.get());
+          TernaryMiddle = ExprError();
+        }
+      } else if (Tok.isNot(tok::colon)) {
+        // Don't parse FOO:BAR as if it were a typo for FOO::BAR.
+        ColonProtectionRAIIObject X(*this);
+
+        // Handle this production specially:
+        //   logical-OR-expression '?' expression ':' conditional-expression
+        // In particular, the RHS of the '?' is 'expression', not
+        // 'logical-OR-expression' as we might expect.
+        TernaryMiddle = ParseExpression();
+      } else {
+        // Special case handling of "X ? Y : Z" where Y is empty:
+        //   logical-OR-expression '?' ':' conditional-expression   [GNU]
+        TernaryMiddle = nullptr;
+        Diag(Tok, diag::ext_gnu_conditional_expr);
+      }
+
+      if (TernaryMiddle.isInvalid()) {
+        Actions.CorrectDelayedTyposInExpr(LHS);
+        LHS = ExprError();
+        TernaryMiddle = nullptr;
+      }
+
+      if (!TryConsumeToken(tok::colon, ColonLoc)) {
+        // Otherwise, we're missing a ':'.  Assume that this was a typo that
+        // the user forgot. If we're not in a macro expansion, we can suggest
+        // a fixit hint. If there were two spaces before the current token,
+        // suggest inserting the colon in between them, otherwise insert ": ".
+        SourceLocation FILoc = Tok.getLocation();
+        const char *FIText = ": ";
+        const SourceManager &SM = PP.getSourceManager();
+        if (FILoc.isFileID() || PP.isAtStartOfMacroExpansion(FILoc, &FILoc)) {
+          assert(FILoc.isFileID());
+          bool IsInvalid = false;
+          const char *SourcePtr =
+            SM.getCharacterData(FILoc.getLocWithOffset(-1), &IsInvalid);
+          if (!IsInvalid && *SourcePtr == ' ') {
+            SourcePtr =
+              SM.getCharacterData(FILoc.getLocWithOffset(-2), &IsInvalid);
+            if (!IsInvalid && *SourcePtr == ' ') {
+              FILoc = FILoc.getLocWithOffset(-1);
+              FIText = ":";
+            }
+          }
+        }
+
+        Diag(Tok, diag::err_expected)
+            << tok::colon << FixItHint::CreateInsertion(FILoc, FIText);
+        Diag(OpToken, diag::note_matching) << tok::question;
+        ColonLoc = Tok.getLocation();
+      }
+    }
+
+    PreferredType.enterBinary(Actions, Tok.getLocation(), LHS.get(),
+                              OpToken.getKind());
+    // Parse another leaf here for the RHS of the operator.
+    // ParseCastExpression works here because all RHS expressions in C have it
+    // as a prefix, at least. However, in C++, an assignment-expression could
+    // be a throw-expression, which is not a valid cast-expression.
+    // Therefore we need some special-casing here.
+    // Also note that the third operand of the conditional operator is
+    // an assignment-expression in C++, and in C++11, we can have a
+    // braced-init-list on the RHS of an assignment. For better diagnostics,
+    // parse as if we were allowed braced-init-lists everywhere, and check that
+    // they only appear on the RHS of assignments later.
+    ExprResult RHS;
+    bool RHSIsInitList = false;
+    if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
+      RHS = ParseBraceInitializer();
+      RHSIsInitList = true;
+    } else if (getLangOpts().CPlusPlus && NextTokPrec <= prec::Conditional)
+      RHS = ParseAssignmentExpression();
+    else
+      RHS = ParseCastExpression(AnyCastExpr);
+
+    if (RHS.isInvalid()) {
+      // FIXME: Errors generated by the delayed typo correction should be
+      // printed before errors from parsing the RHS, not after.
+      Actions.CorrectDelayedTyposInExpr(LHS);
+      if (TernaryMiddle.isUsable())
+        TernaryMiddle = Actions.CorrectDelayedTyposInExpr(TernaryMiddle);
+      LHS = ExprError();
+    }
+
+    // Remember the precedence of this operator and get the precedence of the
+    // operator immediately to the right of the RHS.
+    prec::Level ThisPrec = NextTokPrec;
+    NextTokPrec = getBinOpPrecedence(Tok.getKind(), GreaterThanIsOperator,
+                                     getLangOpts().CPlusPlus11);
+
+    // Assignment and conditional expressions are right-associative.
+    bool isRightAssoc = ThisPrec == prec::Conditional ||
+                        ThisPrec == prec::Assignment;
+
+    // Get the precedence of the operator to the right of the RHS.  If it binds
+    // more tightly with RHS than we do, evaluate it completely first.
+    if (ThisPrec < NextTokPrec ||
+        (ThisPrec == NextTokPrec && isRightAssoc)) {
+      if (!RHS.isInvalid() && RHSIsInitList) {
+        Diag(Tok, diag::err_init_list_bin_op)
+          << /*LHS*/0 << PP.getSpelling(Tok) << Actions.getExprRange(RHS.get());
+        RHS = ExprError();
+      }
+      // If this is left-associative, only parse things on the RHS that bind
+      // more tightly than the current operator.  If it is left-associative, it
+      // is okay, to bind exactly as tightly.  For example, compile A=B=C=D as
+      // A=(B=(C=D)), where each paren is a level of recursion here.
+      // The function takes ownership of the RHS.
+      RHS = ParseRHSOfBinaryExpression(RHS,
+                            static_cast<prec::Level>(ThisPrec + !isRightAssoc));
+      RHSIsInitList = false;
+
+      if (RHS.isInvalid()) {
+        // FIXME: Errors generated by the delayed typo correction should be
+        // printed before errors from ParseRHSOfBinaryExpression, not after.
+        Actions.CorrectDelayedTyposInExpr(LHS);
+        if (TernaryMiddle.isUsable())
+          TernaryMiddle = Actions.CorrectDelayedTyposInExpr(TernaryMiddle);
+        LHS = ExprError();
+      }
+
+      NextTokPrec = getBinOpPrecedence(Tok.getKind(), GreaterThanIsOperator,
+                                       getLangOpts().CPlusPlus11);
+    }
+
+    if (!RHS.isInvalid() && RHSIsInitList) {
+      if (ThisPrec == prec::Assignment) {
+        Diag(OpToken, diag::warn_cxx98_compat_generalized_initializer_lists)
+          << Actions.getExprRange(RHS.get());
+      } else if (ColonLoc.isValid()) {
+        Diag(ColonLoc, diag::err_init_list_bin_op)
+          << /*RHS*/1 << ":"
+          << Actions.getExprRange(RHS.get());
+        LHS = ExprError();
+      } else {
+        Diag(OpToken, diag::err_init_list_bin_op)
+          << /*RHS*/1 << PP.getSpelling(OpToken)
+          << Actions.getExprRange(RHS.get());
+        LHS = ExprError();
+      }
+    }
+
+    ExprResult OrigLHS = LHS;
+    if (!LHS.isInvalid()) {
+      // Combine the LHS and RHS into the LHS (e.g. build AST).
+      if (TernaryMiddle.isInvalid()) {
+        // If we're using '>>' as an operator within a template
+        // argument list (in C++98), suggest the addition of
+        // parentheses so that the code remains well-formed in C++0x.
+        if (!GreaterThanIsOperator && OpToken.is(tok::greatergreater))
+          SuggestParentheses(OpToken.getLocation(),
+                             diag::warn_cxx11_right_shift_in_template_arg,
+                         SourceRange(Actions.getExprRange(LHS.get()).getBegin(),
+                                     Actions.getExprRange(RHS.get()).getEnd()));
+
+        LHS = Actions.ActOnBinOp(getCurScope(), OpToken.getLocation(),
+                                 OpToken.getKind(), LHS.get(), RHS.get());
+
+      } else {
+        LHS = Actions.ActOnConditionalOp(OpToken.getLocation(), ColonLoc,
+                                         LHS.get(), TernaryMiddle.get(),
+                                         RHS.get());
+      }
+      // In this case, ActOnBinOp or ActOnConditionalOp performed the
+      // CorrectDelayedTyposInExpr check.
+      if (!getLangOpts().CPlusPlus)
+        continue;
+    }
+
+    // Ensure potential typos aren't left undiagnosed.
+    if (LHS.isInvalid()) {
+      Actions.CorrectDelayedTyposInExpr(OrigLHS);
+      Actions.CorrectDelayedTyposInExpr(TernaryMiddle);
+      Actions.CorrectDelayedTyposInExpr(RHS);
+    }
+  }
+}
+
+/// Parse a cast-expression, unary-expression or primary-expression, based
+/// on \p ExprType.
+///
+/// \p isAddressOfOperand exists because an id-expression that is the
+/// operand of address-of gets special treatment due to member pointers.
+///
+ExprResult Parser::ParseCastExpression(CastParseKind ParseKind,
+                                       bool isAddressOfOperand,
+                                       TypeCastState isTypeCast,
+                                       bool isVectorLiteral,
+                                       bool *NotPrimaryExpression) {
+  bool NotCastExpr;
+  ExprResult Res = ParseCastExpression(ParseKind,
+                                       isAddressOfOperand,
+                                       NotCastExpr,
+                                       isTypeCast,
+                                       isVectorLiteral,
+                                       NotPrimaryExpression);
+  if (NotCastExpr)
+    Diag(Tok, diag::err_expected_expression);
+  return Res;
+}
+
+namespace {
+class CastExpressionIdValidator final : public CorrectionCandidateCallback {
+ public:
+  CastExpressionIdValidator(Token Next, bool AllowTypes, bool AllowNonTypes)
+      : NextToken(Next), AllowNonTypes(AllowNonTypes) {
+    WantTypeSpecifiers = WantFunctionLikeCasts = AllowTypes;
+  }
+
+  bool ValidateCandidate(const TypoCorrection &candidate) override {
+    NamedDecl *ND = candidate.getCorrectionDecl();
+    if (!ND)
+      return candidate.isKeyword();
+
+    if (isa<TypeDecl>(ND))
+      return WantTypeSpecifiers;
+
+    if (!AllowNonTypes || !CorrectionCandidateCallback::ValidateCandidate(candidate))
+      return false;
+
+    if (!NextToken.isOneOf(tok::equal, tok::arrow, tok::period))
+      return true;
+
+    for (auto *C : candidate) {
+      NamedDecl *ND = C->getUnderlyingDecl();
+      if (isa<ValueDecl>(ND) && !isa<FunctionDecl>(ND))
+        return true;
+    }
+    return false;
+  }
+
+  std::unique_ptr<CorrectionCandidateCallback> clone() override {
+    return std::make_unique<CastExpressionIdValidator>(*this);
+  }
+
+ private:
+  Token NextToken;
+  bool AllowNonTypes;
+};
+}
+
+/// Parse a cast-expression, or, if \pisUnaryExpression is true, parse
+/// a unary-expression.
+///
+/// \p isAddressOfOperand exists because an id-expression that is the operand
+/// of address-of gets special treatment due to member pointers. NotCastExpr
+/// is set to true if the token is not the start of a cast-expression, and no
+/// diagnostic is emitted in this case and no tokens are consumed.
+///
+/// \verbatim
+///       cast-expression: [C99 6.5.4]
+///         unary-expression
+///         '(' type-name ')' cast-expression
+///
+///       unary-expression:  [C99 6.5.3]
+///         postfix-expression
+///         '++' unary-expression
+///         '--' unary-expression
+/// [Coro]  'co_await' cast-expression
+///         unary-operator cast-expression
+///         'sizeof' unary-expression
+///         'sizeof' '(' type-name ')'
+/// [C++11] 'sizeof' '...' '(' identifier ')'
+/// [GNU]   '__alignof' unary-expression
+/// [GNU]   '__alignof' '(' type-name ')'
+/// [C11]   '_Alignof' '(' type-name ')'
+/// [C++11] 'alignof' '(' type-id ')'
+/// [GNU]   '&&' identifier
+/// [C++11] 'noexcept' '(' expression ')' [C++11 5.3.7]
+/// [C++]   new-expression
+/// [C++]   delete-expression
+///
+///       unary-operator: one of
+///         '&'  '*'  '+'  '-'  '~'  '!'
+/// [GNU]   '__extension__'  '__real'  '__imag'
+///
+///       primary-expression: [C99 6.5.1]
+/// [C99]   identifier
+/// [C++]   id-expression
+///         constant
+///         string-literal
+/// [C++]   boolean-literal  [C++ 2.13.5]
+/// [C++11] 'nullptr'        [C++11 2.14.7]
+/// [C++11] user-defined-literal
+///         '(' expression ')'
+/// [C11]   generic-selection
+/// [C++2a] requires-expression
+///         '__func__'        [C99 6.4.2.2]
+/// [GNU]   '__FUNCTION__'
+/// [MS]    '__FUNCDNAME__'
+/// [MS]    'L__FUNCTION__'
+/// [MS]    '__FUNCSIG__'
+/// [MS]    'L__FUNCSIG__'
+/// [GNU]   '__PRETTY_FUNCTION__'
+/// [GNU]   '(' compound-statement ')'
+/// [GNU]   '__builtin_va_arg' '(' assignment-expression ',' type-name ')'
+/// [GNU]   '__builtin_offsetof' '(' type-name ',' offsetof-member-designator')'
+/// [GNU]   '__builtin_choose_expr' '(' assign-expr ',' assign-expr ','
+///                                     assign-expr ')'
+/// [GNU]   '__builtin_FILE' '(' ')'
+/// [GNU]   '__builtin_FUNCTION' '(' ')'
+/// [GNU]   '__builtin_LINE' '(' ')'
+/// [CLANG] '__builtin_COLUMN' '(' ')'
+/// [GNU]   '__builtin_types_compatible_p' '(' type-name ',' type-name ')'
+/// [GNU]   '__null'
+/// [OBJC]  '[' objc-message-expr ']'
+/// [OBJC]  '\@selector' '(' objc-selector-arg ')'
+/// [OBJC]  '\@protocol' '(' identifier ')'
+/// [OBJC]  '\@encode' '(' type-name ')'
+/// [OBJC]  objc-string-literal
+/// [C++]   simple-type-specifier '(' expression-list[opt] ')'      [C++ 5.2.3]
+/// [C++11] simple-type-specifier braced-init-list                  [C++11 5.2.3]
+/// [C++]   typename-specifier '(' expression-list[opt] ')'         [C++ 5.2.3]
+/// [C++11] typename-specifier braced-init-list                     [C++11 5.2.3]
+/// [C++]   'const_cast' '<' type-name '>' '(' expression ')'       [C++ 5.2p1]
+/// [C++]   'dynamic_cast' '<' type-name '>' '(' expression ')'     [C++ 5.2p1]
+/// [C++]   'reinterpret_cast' '<' type-name '>' '(' expression ')' [C++ 5.2p1]
+/// [C++]   'static_cast' '<' type-name '>' '(' expression ')'      [C++ 5.2p1]
+/// [C++]   'typeid' '(' expression ')'                             [C++ 5.2p1]
+/// [C++]   'typeid' '(' type-id ')'                                [C++ 5.2p1]
+/// [C++]   'this'          [C++ 9.3.2]
+/// [G++]   unary-type-trait '(' type-id ')'
+/// [G++]   binary-type-trait '(' type-id ',' type-id ')'           [TODO]
+/// [EMBT]  array-type-trait '(' type-id ',' integer ')'
+/// [clang] '^' block-literal
+///
+///       constant: [C99 6.4.4]
+///         integer-constant
+///         floating-constant
+///         enumeration-constant -> identifier
+///         character-constant
+///
+///       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
+///
+///       new-expression: [C++ 5.3.4]
+///                   '::'[opt] 'new' new-placement[opt] new-type-id
+///                                     new-initializer[opt]
+///                   '::'[opt] 'new' new-placement[opt] '(' type-id ')'
+///                                     new-initializer[opt]
+///
+///       delete-expression: [C++ 5.3.5]
+///                   '::'[opt] 'delete' cast-expression
+///                   '::'[opt] 'delete' '[' ']' cast-expression
+///
+/// [GNU/Embarcadero] unary-type-trait:
+///                   '__is_arithmetic'
+///                   '__is_floating_point'
+///                   '__is_integral'
+///                   '__is_lvalue_expr'
+///                   '__is_rvalue_expr'
+///                   '__is_complete_type'
+///                   '__is_void'
+///                   '__is_array'
+///                   '__is_function'
+///                   '__is_reference'
+///                   '__is_lvalue_reference'
+///                   '__is_rvalue_reference'
+///                   '__is_fundamental'
+///                   '__is_object'
+///                   '__is_scalar'
+///                   '__is_compound'
+///                   '__is_pointer'
+///                   '__is_member_object_pointer'
+///                   '__is_member_function_pointer'
+///                   '__is_member_pointer'
+///                   '__is_const'
+///                   '__is_volatile'
+///                   '__is_trivial'
+///                   '__is_standard_layout'
+///                   '__is_signed'
+///                   '__is_unsigned'
+///
+/// [GNU] unary-type-trait:
+///                   '__has_nothrow_assign'
+///                   '__has_nothrow_copy'
+///                   '__has_nothrow_constructor'
+///                   '__has_trivial_assign'                  [TODO]
+///                   '__has_trivial_copy'                    [TODO]
+///                   '__has_trivial_constructor'
+///                   '__has_trivial_destructor'
+///                   '__has_virtual_destructor'
+///                   '__is_abstract'                         [TODO]
+///                   '__is_class'
+///                   '__is_empty'                            [TODO]
+///                   '__is_enum'
+///                   '__is_final'
+///                   '__is_pod'
+///                   '__is_polymorphic'
+///                   '__is_sealed'                           [MS]
+///                   '__is_trivial'
+///                   '__is_union'
+///                   '__has_unique_object_representations'
+///
+/// [Clang] unary-type-trait:
+///                   '__is_aggregate'
+///                   '__trivially_copyable'
+///
+///       binary-type-trait:
+/// [GNU]             '__is_base_of'
+/// [MS]              '__is_convertible_to'
+///                   '__is_convertible'
+///                   '__is_same'
+///
+/// [Embarcadero] array-type-trait:
+///                   '__array_rank'
+///                   '__array_extent'
+///
+/// [Embarcadero] expression-trait:
+///                   '__is_lvalue_expr'
+///                   '__is_rvalue_expr'
+/// \endverbatim
+///
+ExprResult Parser::ParseCastExpression(CastParseKind ParseKind,
+                                       bool isAddressOfOperand,
+                                       bool &NotCastExpr,
+                                       TypeCastState isTypeCast,
+                                       bool isVectorLiteral,
+                                       bool *NotPrimaryExpression) {
+  ExprResult Res;
+  tok::TokenKind SavedKind = Tok.getKind();
+  auto SavedType = PreferredType;
+  NotCastExpr = false;
+
+  // This handles all of cast-expression, unary-expression, postfix-expression,
+  // and primary-expression.  We handle them together like this for efficiency
+  // and to simplify handling of an expression starting with a '(' token: which
+  // may be one of a parenthesized expression, cast-expression, compound literal
+  // expression, or statement expression.
+  //
+  // If the parsed tokens consist of a primary-expression, the cases below
+  // break out of the switch;  at the end we call ParsePostfixExpressionSuffix
+  // to handle the postfix expression suffixes.  Cases that cannot be followed
+  // by postfix exprs should return without invoking
+  // ParsePostfixExpressionSuffix.
+  switch (SavedKind) {
+  case tok::l_paren: {
+    // If this expression is limited to being a unary-expression, the paren can
+    // not start a cast expression.
+    ParenParseOption ParenExprType;
+    switch (ParseKind) {
+      case CastParseKind::UnaryExprOnly:
+        if (!getLangOpts().CPlusPlus)
+          ParenExprType = CompoundLiteral;
+        LLVM_FALLTHROUGH;
+      case CastParseKind::AnyCastExpr:
+        ParenExprType = ParenParseOption::CastExpr;
+        break;
+      case CastParseKind::PrimaryExprOnly:
+        ParenExprType = FoldExpr;
+        break;
+    }
+    ParsedType CastTy;
+    SourceLocation RParenLoc;
+    Res = ParseParenExpression(ParenExprType, false/*stopIfCastExr*/,
+                               isTypeCast == IsTypeCast, CastTy, RParenLoc);
+
+    if (isVectorLiteral)
+        return Res;
+
+    switch (ParenExprType) {
+    case SimpleExpr:   break;    // Nothing else to do.
+    case CompoundStmt: break;  // Nothing else to do.
+    case CompoundLiteral:
+      // We parsed '(' type-name ')' '{' ... '}'.  If any suffixes of
+      // postfix-expression exist, parse them now.
+      break;
+    case CastExpr:
+      // We have parsed the cast-expression and no postfix-expr pieces are
+      // following.
+      return Res;
+    case FoldExpr:
+      // We only parsed a fold-expression. There might be postfix-expr pieces
+      // afterwards; parse them now.
+      break;
+    }
+
+    break;
+  }
+
+    // primary-expression
+  case tok::numeric_constant:
+    // constant: integer-constant
+    // constant: floating-constant
+
+    Res = Actions.ActOnNumericConstant(Tok, /*UDLScope*/getCurScope());
+    ConsumeToken();
+    break;
+
+  case tok::kw_true:
+  case tok::kw_false:
+    Res = ParseCXXBoolLiteral();
+    break;
+
+  case tok::kw___objc_yes:
+  case tok::kw___objc_no:
+      return ParseObjCBoolLiteral();
+
+  case tok::kw_nullptr:
+    Diag(Tok, diag::warn_cxx98_compat_nullptr);
+    return Actions.ActOnCXXNullPtrLiteral(ConsumeToken());
+
+  case tok::annot_primary_expr:
+    Res = getExprAnnotation(Tok);
+    ConsumeAnnotationToken();
+    if (!Res.isInvalid() && Tok.is(tok::less))
+      checkPotentialAngleBracket(Res);
+    break;
+
+  case tok::annot_non_type:
+  case tok::annot_non_type_dependent:
+  case tok::annot_non_type_undeclared: {
+    CXXScopeSpec SS;
+    Token Replacement;
+    Res = tryParseCXXIdExpression(SS, isAddressOfOperand, Replacement);
+    assert(!Res.isUnset() &&
+           "should not perform typo correction on annotation token");
+    break;
+  }
+
+  case tok::kw___super:
+  case tok::kw_decltype:
+    // Annotate the token and tail recurse.
+    if (TryAnnotateTypeOrScopeToken())
+      return ExprError();
+    assert(Tok.isNot(tok::kw_decltype) && Tok.isNot(tok::kw___super));
+    return ParseCastExpression(ParseKind, isAddressOfOperand, isTypeCast,
+                               isVectorLiteral, NotPrimaryExpression);
+      
+  case tok::identifier: {      // primary-expression: identifier
+                               // unqualified-id: identifier
+                               // constant: enumeration-constant
+    // Turn a potentially qualified name into a annot_typename or
+    // annot_cxxscope if it would be valid.  This handles things like x::y, etc.
+    if (getLangOpts().CPlusPlus) {
+      // Avoid the unnecessary parse-time lookup in the common case
+      // where the syntax forbids a type.
+      const Token &Next = NextToken();
+
+      // If this identifier was reverted from a token ID, and the next token
+      // is a parenthesis, this is likely to be a use of a type trait. Check
+      // those tokens.
+      if (Next.is(tok::l_paren) &&
+          Tok.is(tok::identifier) &&
+          Tok.getIdentifierInfo()->hasRevertedTokenIDToIdentifier()) {
+        IdentifierInfo *II = Tok.getIdentifierInfo();
+        // Build up the mapping of revertible type traits, for future use.
+        if (RevertibleTypeTraits.empty()) {
+#define RTT_JOIN(X,Y) X##Y
+#define REVERTIBLE_TYPE_TRAIT(Name)                         \
+          RevertibleTypeTraits[PP.getIdentifierInfo(#Name)] \
+            = RTT_JOIN(tok::kw_,Name)
+
+          REVERTIBLE_TYPE_TRAIT(__is_abstract);
+          REVERTIBLE_TYPE_TRAIT(__is_aggregate);
+          REVERTIBLE_TYPE_TRAIT(__is_arithmetic);
+          REVERTIBLE_TYPE_TRAIT(__is_array);
+          REVERTIBLE_TYPE_TRAIT(__is_assignable);
+          REVERTIBLE_TYPE_TRAIT(__is_base_of);
+          REVERTIBLE_TYPE_TRAIT(__is_class);
+          REVERTIBLE_TYPE_TRAIT(__is_complete_type);
+          REVERTIBLE_TYPE_TRAIT(__is_compound);
+          REVERTIBLE_TYPE_TRAIT(__is_const);
+          REVERTIBLE_TYPE_TRAIT(__is_constructible);
+          REVERTIBLE_TYPE_TRAIT(__is_convertible);
+          REVERTIBLE_TYPE_TRAIT(__is_convertible_to);
+          REVERTIBLE_TYPE_TRAIT(__is_destructible);
+          REVERTIBLE_TYPE_TRAIT(__is_empty);
+          REVERTIBLE_TYPE_TRAIT(__is_enum);
+          REVERTIBLE_TYPE_TRAIT(__is_floating_point);
+          REVERTIBLE_TYPE_TRAIT(__is_final);
+          REVERTIBLE_TYPE_TRAIT(__is_function);
+          REVERTIBLE_TYPE_TRAIT(__is_fundamental);
+          REVERTIBLE_TYPE_TRAIT(__is_integral);
+          REVERTIBLE_TYPE_TRAIT(__is_interface_class);
+          REVERTIBLE_TYPE_TRAIT(__is_literal);
+          REVERTIBLE_TYPE_TRAIT(__is_lvalue_expr);
+          REVERTIBLE_TYPE_TRAIT(__is_lvalue_reference);
+          REVERTIBLE_TYPE_TRAIT(__is_member_function_pointer);
+          REVERTIBLE_TYPE_TRAIT(__is_member_object_pointer);
+          REVERTIBLE_TYPE_TRAIT(__is_member_pointer);
+          REVERTIBLE_TYPE_TRAIT(__is_nothrow_assignable);
+          REVERTIBLE_TYPE_TRAIT(__is_nothrow_constructible);
+          REVERTIBLE_TYPE_TRAIT(__is_nothrow_destructible);
+          REVERTIBLE_TYPE_TRAIT(__is_object);
+          REVERTIBLE_TYPE_TRAIT(__is_pod);
+          REVERTIBLE_TYPE_TRAIT(__is_pointer);
+          REVERTIBLE_TYPE_TRAIT(__is_polymorphic);
+          REVERTIBLE_TYPE_TRAIT(__is_reference);
+          REVERTIBLE_TYPE_TRAIT(__is_rvalue_expr);
+          REVERTIBLE_TYPE_TRAIT(__is_rvalue_reference);
+          REVERTIBLE_TYPE_TRAIT(__is_same);
+          REVERTIBLE_TYPE_TRAIT(__is_scalar);
+          REVERTIBLE_TYPE_TRAIT(__is_sealed);
+          REVERTIBLE_TYPE_TRAIT(__is_signed);
+          REVERTIBLE_TYPE_TRAIT(__is_standard_layout);
+          REVERTIBLE_TYPE_TRAIT(__is_trivial);
+          REVERTIBLE_TYPE_TRAIT(__is_trivially_assignable);
+          REVERTIBLE_TYPE_TRAIT(__is_trivially_constructible);
+          REVERTIBLE_TYPE_TRAIT(__is_trivially_copyable);
+          REVERTIBLE_TYPE_TRAIT(__is_union);
+          REVERTIBLE_TYPE_TRAIT(__is_unsigned);
+          REVERTIBLE_TYPE_TRAIT(__is_void);
+          REVERTIBLE_TYPE_TRAIT(__is_volatile);
+#undef REVERTIBLE_TYPE_TRAIT
+#undef RTT_JOIN
+        }
+
+        // If we find that this is in fact the name of a type trait,
+        // update the token kind in place and parse again to treat it as
+        // the appropriate kind of type trait.
+        llvm::SmallDenseMap<IdentifierInfo *, tok::TokenKind>::iterator Known
+          = RevertibleTypeTraits.find(II);
+        if (Known != RevertibleTypeTraits.end()) {
+          Tok.setKind(Known->second);
+          return ParseCastExpression(ParseKind, isAddressOfOperand,
+                                     NotCastExpr, isTypeCast,
+                                     isVectorLiteral, NotPrimaryExpression);
+        }
+      }
+
+      if ((!ColonIsSacred && Next.is(tok::colon)) ||
+          Next.isOneOf(tok::coloncolon, tok::less, tok::l_paren,
+                       tok::l_brace)) {
+        // If TryAnnotateTypeOrScopeToken annotates the token, tail recurse.
+        if (TryAnnotateTypeOrScopeToken())
+          return ExprError();
+        if (!Tok.is(tok::identifier))
+          return ParseCastExpression(ParseKind, isAddressOfOperand,
+                                     NotCastExpr, isTypeCast,
+                                     isVectorLiteral,
+                                     NotPrimaryExpression);
+      }
+    }
+
+    // Consume the identifier so that we can see if it is followed by a '(' or
+    // '.'.
+    IdentifierInfo &II = *Tok.getIdentifierInfo();
+    SourceLocation ILoc = ConsumeToken();
+
+    // Support 'Class.property' and 'super.property' notation.
+    if (getLangOpts().ObjC && Tok.is(tok::period) &&
+        (Actions.getTypeName(II, ILoc, getCurScope()) ||
+         // Allow the base to be 'super' if in an objc-method.
+         (&II == Ident_super && getCurScope()->isInObjcMethodScope()))) {
+      ConsumeToken();
+
+      if (Tok.is(tok::code_completion) && &II != Ident_super) {
+        Actions.CodeCompleteObjCClassPropertyRefExpr(
+            getCurScope(), II, ILoc, ExprStatementTokLoc == ILoc);
+        cutOffParsing();
+        return ExprError();
+      }
+      // Allow either an identifier or the keyword 'class' (in C++).
+      if (Tok.isNot(tok::identifier) &&
+          !(getLangOpts().CPlusPlus && Tok.is(tok::kw_class))) {
+        Diag(Tok, diag::err_expected_property_name);
+        return ExprError();
+      }
+      IdentifierInfo &PropertyName = *Tok.getIdentifierInfo();
+      SourceLocation PropertyLoc = ConsumeToken();
+
+      Res = Actions.ActOnClassPropertyRefExpr(II, PropertyName,
+                                              ILoc, PropertyLoc);
+      break;
+    }
+
+    // In an Objective-C method, if we have "super" followed by an identifier,
+    // the token sequence is ill-formed. However, if there's a ':' or ']' after
+    // that identifier, this is probably a message send with a missing open
+    // bracket. Treat it as such.
+    if (getLangOpts().ObjC && &II == Ident_super && !InMessageExpression &&
+        getCurScope()->isInObjcMethodScope() &&
+        ((Tok.is(tok::identifier) &&
+         (NextToken().is(tok::colon) || NextToken().is(tok::r_square))) ||
+         Tok.is(tok::code_completion))) {
+      Res = ParseObjCMessageExpressionBody(SourceLocation(), ILoc, nullptr,
+                                           nullptr);
+      break;
+    }
+
+    // If we have an Objective-C class name followed by an identifier
+    // and either ':' or ']', this is an Objective-C class message
+    // send that's missing the opening '['. Recovery
+    // appropriately. Also take this path if we're performing code
+    // completion after an Objective-C class name.
+    if (getLangOpts().ObjC &&
+        ((Tok.is(tok::identifier) && !InMessageExpression) ||
+         Tok.is(tok::code_completion))) {
+      const Token& Next = NextToken();
+      if (Tok.is(tok::code_completion) ||
+          Next.is(tok::colon) || Next.is(tok::r_square))
+        if (ParsedType Typ = Actions.getTypeName(II, ILoc, getCurScope()))
+          if (Typ.get()->isObjCObjectOrInterfaceType()) {
+            // Fake up a Declarator to use with ActOnTypeName.
+            DeclSpec DS(AttrFactory);
+            DS.SetRangeStart(ILoc);
+            DS.SetRangeEnd(ILoc);
+            const char *PrevSpec = nullptr;
+            unsigned DiagID;
+            DS.SetTypeSpecType(TST_typename, ILoc, PrevSpec, DiagID, Typ,
+                               Actions.getASTContext().getPrintingPolicy());
+
+            Declarator DeclaratorInfo(DS, DeclaratorContext::TypeNameContext);
+            TypeResult Ty = Actions.ActOnTypeName(getCurScope(),
+                                                  DeclaratorInfo);
+            if (Ty.isInvalid())
+              break;
+
+            Res = ParseObjCMessageExpressionBody(SourceLocation(),
+                                                 SourceLocation(),
+                                                 Ty.get(), nullptr);
+            break;
+          }
+    }
+
+    // Make sure to pass down the right value for isAddressOfOperand.
+    if (isAddressOfOperand && isPostfixExpressionSuffixStart())
+      isAddressOfOperand = false;
+
+    // Function designators are allowed to be undeclared (C99 6.5.1p2), so we
+    // need to know whether or not this identifier is a function designator or
+    // not.
+    UnqualifiedId Name;
+    CXXScopeSpec ScopeSpec;
+    SourceLocation TemplateKWLoc;
+    Token Replacement;
+    CastExpressionIdValidator Validator(
+        /*Next=*/Tok,
+        /*AllowTypes=*/isTypeCast != NotTypeCast,
+        /*AllowNonTypes=*/isTypeCast != IsTypeCast);
+    Validator.IsAddressOfOperand = isAddressOfOperand;
+    if (Tok.isOneOf(tok::periodstar, tok::arrowstar)) {
+      Validator.WantExpressionKeywords = false;
+      Validator.WantRemainingKeywords = false;
+    } else {
+      Validator.WantRemainingKeywords = Tok.isNot(tok::r_paren);
+    }
+    Name.setIdentifier(&II, ILoc);
+    Res = Actions.ActOnIdExpression(
+        getCurScope(), ScopeSpec, TemplateKWLoc, Name, Tok.is(tok::l_paren),
+        isAddressOfOperand, &Validator,
+        /*IsInlineAsmIdentifier=*/false,
+        Tok.is(tok::r_paren) ? nullptr : &Replacement);
+    if (!Res.isInvalid() && Res.isUnset()) {
+      UnconsumeToken(Replacement);
+      return ParseCastExpression(ParseKind, isAddressOfOperand,
+                                 NotCastExpr, isTypeCast,
+                                 /*isVectorLiteral=*/false,
+                                 NotPrimaryExpression);
+    }
+    if (!Res.isInvalid() && Tok.is(tok::less))
+      checkPotentialAngleBracket(Res);
+    break;
+  }
+  case tok::char_constant:     // constant: character-constant
+  case tok::wide_char_constant:
+  case tok::utf8_char_constant:
+  case tok::utf16_char_constant:
+  case tok::utf32_char_constant:
+    Res = Actions.ActOnCharacterConstant(Tok, /*UDLScope*/getCurScope());
+    ConsumeToken();
+    break;
+  case tok::kw___func__:       // primary-expression: __func__ [C99 6.4.2.2]
+  case tok::kw___FUNCTION__:   // primary-expression: __FUNCTION__ [GNU]
+  case tok::kw___FUNCDNAME__:   // primary-expression: __FUNCDNAME__ [MS]
+  case tok::kw___FUNCSIG__:     // primary-expression: __FUNCSIG__ [MS]
+  case tok::kw_L__FUNCTION__:   // primary-expression: L__FUNCTION__ [MS]
+  case tok::kw_L__FUNCSIG__:    // primary-expression: L__FUNCSIG__ [MS]
+  case tok::kw___PRETTY_FUNCTION__:  // primary-expression: __P..Y_F..N__ [GNU]
+    Res = Actions.ActOnPredefinedExpr(Tok.getLocation(), SavedKind);
+    ConsumeToken();
+    break;
+  case tok::string_literal:    // primary-expression: string-literal
+  case tok::wide_string_literal:
+  case tok::utf8_string_literal:
+  case tok::utf16_string_literal:
+  case tok::utf32_string_literal:
+    Res = ParseStringLiteralExpression(true);
+    break;
+  case tok::kw__Generic:   // primary-expression: generic-selection [C11 6.5.1]
+    Res = ParseGenericSelectionExpression();
+    break;
+  case tok::kw___builtin_available:
+    return ParseAvailabilityCheckExpr(Tok.getLocation());
+  case tok::kw___builtin_va_arg:
+  case tok::kw___builtin_offsetof:
+  case tok::kw___builtin_choose_expr:
+  case tok::kw___builtin_astype: // primary-expression: [OCL] as_type()
+  case tok::kw___builtin_convertvector:
+  case tok::kw___builtin_COLUMN:
+  case tok::kw___builtin_FILE:
+  case tok::kw___builtin_FUNCTION:
+  case tok::kw___builtin_LINE:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    return ParseBuiltinPrimaryExpression();
+  case tok::kw___null:
+    return Actions.ActOnGNUNullExpr(ConsumeToken());
+
+  case tok::plusplus:      // unary-expression: '++' unary-expression [C99]
+  case tok::minusminus: {  // unary-expression: '--' unary-expression [C99]
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    // C++ [expr.unary] has:
+    //   unary-expression:
+    //     ++ cast-expression
+    //     -- cast-expression
+    Token SavedTok = Tok;
+    ConsumeToken();
+
+    PreferredType.enterUnary(Actions, Tok.getLocation(), SavedTok.getKind(),
+                             SavedTok.getLocation());
+    // One special case is implicitly handled here: if the preceding tokens are
+    // an ambiguous cast expression, such as "(T())++", then we recurse to
+    // determine whether the '++' is prefix or postfix.
+    Res = ParseCastExpression(getLangOpts().CPlusPlus ?
+                                  UnaryExprOnly : AnyCastExpr,
+                              /*isAddressOfOperand*/false, NotCastExpr,
+                              NotTypeCast);
+    if (NotCastExpr) {
+      // If we return with NotCastExpr = true, we must not consume any tokens,
+      // so put the token back where we found it.
+      assert(Res.isInvalid());
+      UnconsumeToken(SavedTok);
+      return ExprError();
+    }
+    if (!Res.isInvalid())
+      Res = Actions.ActOnUnaryOp(getCurScope(), SavedTok.getLocation(),
+                                 SavedKind, Res.get());
+    return Res;
+  }
+  case tok::amp: {         // unary-expression: '&' cast-expression
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    // Special treatment because of member pointers
+    SourceLocation SavedLoc = ConsumeToken();
+    PreferredType.enterUnary(Actions, Tok.getLocation(), tok::amp, SavedLoc);
+    Res = ParseCastExpression(AnyCastExpr, true);
+    if (!Res.isInvalid())
+      Res = Actions.ActOnUnaryOp(getCurScope(), SavedLoc, SavedKind, Res.get());
+    return Res;
+  }
+
+  case tok::star:          // unary-expression: '*' cast-expression
+  case tok::plus:          // unary-expression: '+' cast-expression
+  case tok::minus:         // unary-expression: '-' cast-expression
+  case tok::tilde:         // unary-expression: '~' cast-expression
+  case tok::exclaim:       // unary-expression: '!' cast-expression
+  case tok::kw___real:     // unary-expression: '__real' cast-expression [GNU]
+  case tok::kw___imag: {   // unary-expression: '__imag' cast-expression [GNU]
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    SourceLocation SavedLoc = ConsumeToken();
+    PreferredType.enterUnary(Actions, Tok.getLocation(), SavedKind, SavedLoc);
+    Res = ParseCastExpression(AnyCastExpr);
+    if (!Res.isInvalid())
+      Res = Actions.ActOnUnaryOp(getCurScope(), SavedLoc, SavedKind, Res.get());
+    return Res;
+  }
+
+  case tok::kw_co_await: {  // unary-expression: 'co_await' cast-expression
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    SourceLocation CoawaitLoc = ConsumeToken();
+    Res = ParseCastExpression(AnyCastExpr);
+    if (!Res.isInvalid())
+      Res = Actions.ActOnCoawaitExpr(getCurScope(), CoawaitLoc, Res.get());
+    return Res;
+  }
+
+  case tok::kw___extension__:{//unary-expression:'__extension__' cast-expr [GNU]
+    // __extension__ silences extension warnings in the subexpression.
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    ExtensionRAIIObject O(Diags);  // Use RAII to do this.
+    SourceLocation SavedLoc = ConsumeToken();
+    Res = ParseCastExpression(AnyCastExpr);
+    if (!Res.isInvalid())
+      Res = Actions.ActOnUnaryOp(getCurScope(), SavedLoc, SavedKind, Res.get());
+    return Res;
+  }
+  case tok::kw__Alignof:   // unary-expression: '_Alignof' '(' type-name ')'
+    if (!getLangOpts().C11)
+      Diag(Tok, diag::ext_c11_feature) << Tok.getName();
+    LLVM_FALLTHROUGH;
+  case tok::kw_alignof:    // unary-expression: 'alignof' '(' type-id ')'
+  case tok::kw___alignof:  // unary-expression: '__alignof' unary-expression
+                           // unary-expression: '__alignof' '(' type-name ')'
+  case tok::kw_sizeof:     // unary-expression: 'sizeof' unary-expression
+                           // unary-expression: 'sizeof' '(' type-name ')'
+  case tok::kw_vec_step:   // unary-expression: OpenCL 'vec_step' expression
+  // unary-expression: '__builtin_omp_required_simd_align' '(' type-name ')'
+  case tok::kw___builtin_omp_required_simd_align:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    return ParseUnaryExprOrTypeTraitExpression();
+  case tok::ampamp: {      // unary-expression: '&&' identifier
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    SourceLocation AmpAmpLoc = ConsumeToken();
+    if (Tok.isNot(tok::identifier))
+      return ExprError(Diag(Tok, diag::err_expected) << tok::identifier);
+
+    if (getCurScope()->getFnParent() == nullptr)
+      return ExprError(Diag(Tok, diag::err_address_of_label_outside_fn));
+
+    Diag(AmpAmpLoc, diag::ext_gnu_address_of_label);
+    LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
+                                                Tok.getLocation());
+    Res = Actions.ActOnAddrLabel(AmpAmpLoc, Tok.getLocation(), LD);
+    ConsumeToken();
+    return Res;
+  }
+  case tok::kw_const_cast:
+  case tok::kw_dynamic_cast:
+  case tok::kw_reinterpret_cast:
+  case tok::kw_static_cast:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    Res = ParseCXXCasts();
+    break;
+  case tok::kw___builtin_bit_cast:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    Res = ParseBuiltinBitCast();
+    break;
+  case tok::kw_typeid:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    Res = ParseCXXTypeid();
+    break;
+  case tok::kw___uuidof:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    Res = ParseCXXUuidof();
+    break;
+  case tok::kw_this:
+    Res = ParseCXXThis();
+    break;
+
+  case tok::annot_typename:
+    if (isStartOfObjCClassMessageMissingOpenBracket()) {
+      ParsedType Type = getTypeAnnotation(Tok);
+
+      // Fake up a Declarator to use with ActOnTypeName.
+      DeclSpec DS(AttrFactory);
+      DS.SetRangeStart(Tok.getLocation());
+      DS.SetRangeEnd(Tok.getLastLoc());
+
+      const char *PrevSpec = nullptr;
+      unsigned DiagID;
+      DS.SetTypeSpecType(TST_typename, Tok.getAnnotationEndLoc(),
+                         PrevSpec, DiagID, Type,
+                         Actions.getASTContext().getPrintingPolicy());
+
+      Declarator DeclaratorInfo(DS, DeclaratorContext::TypeNameContext);
+      TypeResult Ty = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
+      if (Ty.isInvalid())
+        break;
+
+      ConsumeAnnotationToken();
+      Res = ParseObjCMessageExpressionBody(SourceLocation(), SourceLocation(),
+                                           Ty.get(), nullptr);
+      break;
+    }
+    LLVM_FALLTHROUGH;
+
+  case tok::annot_decltype:
+  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_bool:
+  case tok::kw_short:
+  case tok::kw_int:
+  case tok::kw_long:
+  case tok::kw___int64:
+  case tok::kw___int128:
+  case tok::kw_signed:
+  case tok::kw_unsigned:
+  case tok::kw_half:
+  case tok::kw_float:
+  case tok::kw_double:
+  case tok::kw__Float16:
+  case tok::kw___float128:
+  case tok::kw_void:
+  case tok::kw_typename:
+  case tok::kw_typeof:
+  case tok::kw___vector:
+#define GENERIC_IMAGE_TYPE(ImgType, Id) case tok::kw_##ImgType##_t:
+#include "clang/Basic/OpenCLImageTypes.def"
+  {
+    if (!getLangOpts().CPlusPlus) {
+      Diag(Tok, diag::err_expected_expression);
+      return ExprError();
+    }
+
+    // Everything henceforth is a postfix-expression.
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+
+    if (SavedKind == tok::kw_typename) {
+      // postfix-expression: typename-specifier '(' expression-list[opt] ')'
+      //                     typename-specifier braced-init-list
+      if (TryAnnotateTypeOrScopeToken())
+        return ExprError();
+
+      if (!Actions.isSimpleTypeSpecifier(Tok.getKind()))
+        // We are trying to parse a simple-type-specifier but might not get such
+        // a token after error recovery.
+        return ExprError();
+    }
+
+    // postfix-expression: simple-type-specifier '(' expression-list[opt] ')'
+    //                     simple-type-specifier braced-init-list
+    //
+    DeclSpec DS(AttrFactory);
+
+    ParseCXXSimpleTypeSpecifier(DS);
+    if (Tok.isNot(tok::l_paren) &&
+        (!getLangOpts().CPlusPlus11 || Tok.isNot(tok::l_brace)))
+      return ExprError(Diag(Tok, diag::err_expected_lparen_after_type)
+                         << DS.getSourceRange());
+
+    if (Tok.is(tok::l_brace))
+      Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
+
+    Res = ParseCXXTypeConstructExpression(DS);
+    break;
+  }
+
+  case tok::annot_cxxscope: { // [C++] id-expression: qualified-id
+    // If TryAnnotateTypeOrScopeToken annotates the token, tail recurse.
+    // (We can end up in this situation after tentative parsing.)
+    if (TryAnnotateTypeOrScopeToken())
+      return ExprError();
+    if (!Tok.is(tok::annot_cxxscope))
+      return ParseCastExpression(ParseKind, isAddressOfOperand, NotCastExpr,
+                                 isTypeCast, isVectorLiteral,
+                                 NotPrimaryExpression);
+
+    Token Next = NextToken();
+    if (Next.is(tok::annot_template_id)) {
+      TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Next);
+      if (TemplateId->Kind == TNK_Type_template) {
+        // We have a qualified template-id that we know refers to a
+        // type, translate it into a type and continue parsing as a
+        // cast expression.
+        CXXScopeSpec SS;
+        ParseOptionalCXXScopeSpecifier(SS, nullptr,
+                                       /*EnteringContext=*/false);
+        AnnotateTemplateIdTokenAsType(SS);
+        return ParseCastExpression(ParseKind, isAddressOfOperand, NotCastExpr,
+                                   isTypeCast, isVectorLiteral,
+                                   NotPrimaryExpression);
+      }
+    }
+
+    // Parse as an id-expression.
+    Res = ParseCXXIdExpression(isAddressOfOperand);
+    break;
+  }
+
+  case tok::annot_template_id: { // [C++]          template-id
+    TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
+    if (TemplateId->Kind == TNK_Type_template) {
+      // We have a template-id that we know refers to a type,
+      // translate it into a type and continue parsing as a cast
+      // expression.
+      CXXScopeSpec SS;
+      AnnotateTemplateIdTokenAsType(SS);
+      return ParseCastExpression(ParseKind, isAddressOfOperand,
+                                 NotCastExpr, isTypeCast, isVectorLiteral,
+                                 NotPrimaryExpression);
+    }
+
+    // Fall through to treat the template-id as an id-expression.
+    LLVM_FALLTHROUGH;
+  }
+
+  case tok::kw_operator: // [C++] id-expression: operator/conversion-function-id
+    Res = ParseCXXIdExpression(isAddressOfOperand);
+    break;
+
+  case tok::coloncolon: {
+    // ::foo::bar -> global qualified name etc.   If TryAnnotateTypeOrScopeToken
+    // annotates the token, tail recurse.
+    if (TryAnnotateTypeOrScopeToken())
+      return ExprError();
+    if (!Tok.is(tok::coloncolon))
+      return ParseCastExpression(ParseKind, isAddressOfOperand, isTypeCast,
+                                 isVectorLiteral, NotPrimaryExpression);
+
+    // ::new -> [C++] new-expression
+    // ::delete -> [C++] delete-expression
+    SourceLocation CCLoc = ConsumeToken();
+    if (Tok.is(tok::kw_new)) {
+      if (NotPrimaryExpression)
+        *NotPrimaryExpression = true;
+      return ParseCXXNewExpression(true, CCLoc);
+    }
+    if (Tok.is(tok::kw_delete)) {
+      if (NotPrimaryExpression)
+        *NotPrimaryExpression = true;
+      return ParseCXXDeleteExpression(true, CCLoc);
+    }
+
+    // This is not a type name or scope specifier, it is an invalid expression.
+    Diag(CCLoc, diag::err_expected_expression);
+    return ExprError();
+  }
+
+  case tok::kw_new: // [C++] new-expression
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    return ParseCXXNewExpression(false, Tok.getLocation());
+
+  case tok::kw_delete: // [C++] delete-expression
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    return ParseCXXDeleteExpression(false, Tok.getLocation());
+
+  case tok::kw_requires: // [C++2a] requires-expression
+    return ParseRequiresExpression();
+
+  case tok::kw_noexcept: { // [C++0x] 'noexcept' '(' expression ')'
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    Diag(Tok, diag::warn_cxx98_compat_noexcept_expr);
+    SourceLocation KeyLoc = ConsumeToken();
+    BalancedDelimiterTracker T(*this, tok::l_paren);
+
+    if (T.expectAndConsume(diag::err_expected_lparen_after, "noexcept"))
+      return ExprError();
+    // C++11 [expr.unary.noexcept]p1:
+    //   The noexcept operator determines whether the evaluation of its operand,
+    //   which is an unevaluated operand, can throw an exception.
+    EnterExpressionEvaluationContext Unevaluated(
+        Actions, Sema::ExpressionEvaluationContext::Unevaluated);
+    ExprResult Result = ParseExpression();
+
+    T.consumeClose();
+
+    if (!Result.isInvalid())
+      Result = Actions.ActOnNoexceptExpr(KeyLoc, T.getOpenLocation(),
+                                         Result.get(), T.getCloseLocation());
+    return Result;
+  }
+
+#define TYPE_TRAIT(N,Spelling,K) \
+  case tok::kw_##Spelling:
+#include "clang/Basic/TokenKinds.def"
+    return ParseTypeTrait();
+
+  case tok::kw___array_rank:
+  case tok::kw___array_extent:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    return ParseArrayTypeTrait();
+
+  case tok::kw___is_lvalue_expr:
+  case tok::kw___is_rvalue_expr:
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    return ParseExpressionTrait();
+
+  case tok::at: {
+    if (NotPrimaryExpression)
+      *NotPrimaryExpression = true;
+    SourceLocation AtLoc = ConsumeToken();
+    return ParseObjCAtExpression(AtLoc);
+  }
+  case tok::caret:
+    Res = ParseBlockLiteralExpression();
+    break;
+  case tok::code_completion: {
+    Actions.CodeCompleteExpression(getCurScope(),
+                                   PreferredType.get(Tok.getLocation()));
+    cutOffParsing();
+    return ExprError();
+  }
+  case tok::l_square:
+    if (getLangOpts().CPlusPlus11) {
+      if (getLangOpts().ObjC) {
+        // C++11 lambda expressions and Objective-C message sends both start with a
+        // square bracket.  There are three possibilities here:
+        // we have a valid lambda expression, we have an invalid lambda
+        // expression, or we have something that doesn't appear to be a lambda.
+        // If we're in the last case, we fall back to ParseObjCMessageExpression.
+        Res = TryParseLambdaExpression();
+        if (!Res.isInvalid() && !Res.get()) {
+          // We assume Objective-C++ message expressions are not
+          // primary-expressions.
+          if (NotPrimaryExpression)
+            *NotPrimaryExpression = true;
+          Res = ParseObjCMessageExpression();
+        }
+        break;
+      }
+      Res = ParseLambdaExpression();
+      break;
+    }
+    if (getLangOpts().ObjC) {
+      Res = ParseObjCMessageExpression();
+      break;
+    }
+    LLVM_FALLTHROUGH;
+  default:
+    NotCastExpr = true;
+    return ExprError();
+  }
+
+  // Check to see whether Res is a function designator only. If it is and we
+  // are compiling for OpenCL, we need to return an error as this implies
+  // that the address of the function is being taken, which is illegal in CL.
+
+  if (ParseKind == PrimaryExprOnly)
+    // This is strictly a primary-expression - no postfix-expr pieces should be
+    // parsed.
+    return Res;
+
+  // These can be followed by postfix-expr pieces.
+  PreferredType = SavedType;
+  Res = ParsePostfixExpressionSuffix(Res);
+  if (getLangOpts().OpenCL)
+    if (Expr *PostfixExpr = Res.get()) {
+      QualType Ty = PostfixExpr->getType();
+      if (!Ty.isNull() && Ty->isFunctionType()) {
+        Diag(PostfixExpr->getExprLoc(),
+             diag::err_opencl_taking_function_address_parser);
+        return ExprError();
+      }
+    }
+
+  return Res;
+}
+
+/// Once the leading part of a postfix-expression is parsed, this
+/// method parses any suffixes that apply.
+///
+/// \verbatim
+///       postfix-expression: [C99 6.5.2]
+///         primary-expression
+///         postfix-expression '[' expression ']'
+///         postfix-expression '[' braced-init-list ']'
+///         postfix-expression '(' argument-expression-list[opt] ')'
+///         postfix-expression '.' identifier
+///         postfix-expression '->' identifier
+///         postfix-expression '++'
+///         postfix-expression '--'
+///         '(' type-name ')' '{' initializer-list '}'
+///         '(' type-name ')' '{' initializer-list ',' '}'
+///
+///       argument-expression-list: [C99 6.5.2]
+///         argument-expression ...[opt]
+///         argument-expression-list ',' assignment-expression ...[opt]
+/// \endverbatim
+ExprResult
+Parser::ParsePostfixExpressionSuffix(ExprResult LHS) {
+  // Now that the primary-expression piece of the postfix-expression has been
+  // parsed, see if there are any postfix-expression pieces here.
+  SourceLocation Loc;
+  auto SavedType = PreferredType;
+  while (1) {
+    // Each iteration relies on preferred type for the whole expression.
+    PreferredType = SavedType;
+    switch (Tok.getKind()) {
+    case tok::code_completion:
+      if (InMessageExpression)
+        return LHS;
+
+      Actions.CodeCompletePostfixExpression(
+          getCurScope(), LHS, PreferredType.get(Tok.getLocation()));
+      cutOffParsing();
+      return ExprError();
+
+    case tok::identifier:
+      // If we see identifier: after an expression, and we're not already in a
+      // message send, then this is probably a message send with a missing
+      // opening bracket '['.
+      if (getLangOpts().ObjC && !InMessageExpression &&
+          (NextToken().is(tok::colon) || NextToken().is(tok::r_square))) {
+        LHS = ParseObjCMessageExpressionBody(SourceLocation(), SourceLocation(),
+                                             nullptr, LHS.get());
+        break;
+      }
+      // Fall through; this isn't a message send.
+      LLVM_FALLTHROUGH;
+
+    default:  // Not a postfix-expression suffix.
+      return LHS;
+    case tok::l_square: {  // postfix-expression: p-e '[' expression ']'
+      // If we have a array postfix expression that starts on a new line and
+      // Objective-C is enabled, it is highly likely that the user forgot a
+      // semicolon after the base expression and that the array postfix-expr is
+      // actually another message send.  In this case, do some look-ahead to see
+      // if the contents of the square brackets are obviously not a valid
+      // expression and recover by pretending there is no suffix.
+      if (getLangOpts().ObjC && Tok.isAtStartOfLine() &&
+          isSimpleObjCMessageExpression())
+        return LHS;
+
+      // Reject array indices starting with a lambda-expression. '[[' is
+      // reserved for attributes.
+      if (CheckProhibitedCXX11Attribute()) {
+        (void)Actions.CorrectDelayedTyposInExpr(LHS);
+        return ExprError();
+      }
+
+      BalancedDelimiterTracker T(*this, tok::l_square);
+      T.consumeOpen();
+      Loc = T.getOpenLocation();
+      ExprResult Idx, Length;
+      SourceLocation ColonLoc;
+      PreferredType.enterSubscript(Actions, Tok.getLocation(), LHS.get());
+      if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
+        Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
+        Idx = ParseBraceInitializer();
+      } else if (getLangOpts().OpenMP) {
+        ColonProtectionRAIIObject RAII(*this);
+        // Parse [: or [ expr or [ expr :
+        if (!Tok.is(tok::colon)) {
+          // [ expr
+          Idx = ParseExpression();
+        }
+        if (Tok.is(tok::colon)) {
+          // Consume ':'
+          ColonLoc = ConsumeToken();
+          if (Tok.isNot(tok::r_square))
+            Length = ParseExpression();
+        }
+      } else
+        Idx = ParseExpression();
+
+      SourceLocation RLoc = Tok.getLocation();
+
+      LHS = Actions.CorrectDelayedTyposInExpr(LHS);
+      Idx = Actions.CorrectDelayedTyposInExpr(Idx);
+      Length = Actions.CorrectDelayedTyposInExpr(Length);
+      if (!LHS.isInvalid() && !Idx.isInvalid() && !Length.isInvalid() &&
+          Tok.is(tok::r_square)) {
+        if (ColonLoc.isValid()) {
+          LHS = Actions.ActOnOMPArraySectionExpr(LHS.get(), Loc, Idx.get(),
+                                                 ColonLoc, Length.get(), RLoc);
+        } else {
+          LHS = Actions.ActOnArraySubscriptExpr(getCurScope(), LHS.get(), Loc,
+                                                Idx.get(), RLoc);
+        }
+      } else {
+        LHS = ExprError();
+        Idx = ExprError();
+      }
+
+      // Match the ']'.
+      T.consumeClose();
+      break;
+    }
+
+    case tok::l_paren:         // p-e: p-e '(' argument-expression-list[opt] ')'
+    case tok::lesslessless: {  // p-e: p-e '<<<' argument-expression-list '>>>'
+                               //   '(' argument-expression-list[opt] ')'
+      tok::TokenKind OpKind = Tok.getKind();
+      InMessageExpressionRAIIObject InMessage(*this, false);
+
+      Expr *ExecConfig = nullptr;
+
+      BalancedDelimiterTracker PT(*this, tok::l_paren);
+
+      if (OpKind == tok::lesslessless) {
+        ExprVector ExecConfigExprs;
+        CommaLocsTy ExecConfigCommaLocs;
+        SourceLocation OpenLoc = ConsumeToken();
+
+        if (ParseSimpleExpressionList(ExecConfigExprs, ExecConfigCommaLocs)) {
+          (void)Actions.CorrectDelayedTyposInExpr(LHS);
+          LHS = ExprError();
+        }
+
+        SourceLocation CloseLoc;
+        if (TryConsumeToken(tok::greatergreatergreater, CloseLoc)) {
+        } else if (LHS.isInvalid()) {
+          SkipUntil(tok::greatergreatergreater, StopAtSemi);
+        } else {
+          // There was an error closing the brackets
+          Diag(Tok, diag::err_expected) << tok::greatergreatergreater;
+          Diag(OpenLoc, diag::note_matching) << tok::lesslessless;
+          SkipUntil(tok::greatergreatergreater, StopAtSemi);
+          LHS = ExprError();
+        }
+
+        if (!LHS.isInvalid()) {
+          if (ExpectAndConsume(tok::l_paren))
+            LHS = ExprError();
+          else
+            Loc = PrevTokLocation;
+        }
+
+        if (!LHS.isInvalid()) {
+          ExprResult ECResult = Actions.ActOnCUDAExecConfigExpr(getCurScope(),
+                                    OpenLoc,
+                                    ExecConfigExprs,
+                                    CloseLoc);
+          if (ECResult.isInvalid())
+            LHS = ExprError();
+          else
+            ExecConfig = ECResult.get();
+        }
+      } else {
+        PT.consumeOpen();
+        Loc = PT.getOpenLocation();
+      }
+
+      ExprVector ArgExprs;
+      CommaLocsTy CommaLocs;
+      auto RunSignatureHelp = [&]() -> QualType {
+        QualType PreferredType = Actions.ProduceCallSignatureHelp(
+            getCurScope(), LHS.get(), ArgExprs, PT.getOpenLocation());
+        CalledSignatureHelp = true;
+        return PreferredType;
+      };
+      if (OpKind == tok::l_paren || !LHS.isInvalid()) {
+        if (Tok.isNot(tok::r_paren)) {
+          if (ParseExpressionList(ArgExprs, CommaLocs, [&] {
+                PreferredType.enterFunctionArgument(Tok.getLocation(),
+                                                    RunSignatureHelp);
+              })) {
+            (void)Actions.CorrectDelayedTyposInExpr(LHS);
+            // If we got an error when parsing expression list, we don't call
+            // the CodeCompleteCall handler inside the parser. So call it here
+            // to make sure we get overload suggestions even when we are in the
+            // middle of a parameter.
+            if (PP.isCodeCompletionReached() && !CalledSignatureHelp)
+              RunSignatureHelp();
+            LHS = ExprError();
+          } else if (LHS.isInvalid()) {
+            for (auto &E : ArgExprs)
+              Actions.CorrectDelayedTyposInExpr(E);
+          }
+        }
+      }
+
+      // Match the ')'.
+      if (LHS.isInvalid()) {
+        SkipUntil(tok::r_paren, StopAtSemi);
+      } else if (Tok.isNot(tok::r_paren)) {
+        bool HadDelayedTypo = false;
+        if (Actions.CorrectDelayedTyposInExpr(LHS).get() != LHS.get())
+          HadDelayedTypo = true;
+        for (auto &E : ArgExprs)
+          if (Actions.CorrectDelayedTyposInExpr(E).get() != E)
+            HadDelayedTypo = true;
+        // If there were delayed typos in the LHS or ArgExprs, call SkipUntil
+        // instead of PT.consumeClose() to avoid emitting extra diagnostics for
+        // the unmatched l_paren.
+        if (HadDelayedTypo)
+          SkipUntil(tok::r_paren, StopAtSemi);
+        else
+          PT.consumeClose();
+        LHS = ExprError();
+      } else {
+        assert((ArgExprs.size() == 0 ||
+                ArgExprs.size()-1 == CommaLocs.size())&&
+               "Unexpected number of commas!");
+        LHS = Actions.ActOnCallExpr(getCurScope(), LHS.get(), Loc,
+                                    ArgExprs, Tok.getLocation(),
+                                    ExecConfig);
+        PT.consumeClose();
+      }
+
+      break;
+    }
+    case tok::arrow:
+    case tok::period: {
+      // postfix-expression: p-e '->' template[opt] id-expression
+      // postfix-expression: p-e '.' template[opt] id-expression
+      tok::TokenKind OpKind = Tok.getKind();
+      SourceLocation OpLoc = ConsumeToken();  // Eat the "." or "->" token.
+
+      CXXScopeSpec SS;
+      ParsedType ObjectType;
+      bool MayBePseudoDestructor = false;
+      Expr* OrigLHS = !LHS.isInvalid() ? LHS.get() : nullptr;
+
+      PreferredType.enterMemAccess(Actions, Tok.getLocation(), OrigLHS);
+
+      if (getLangOpts().CPlusPlus && !LHS.isInvalid()) {
+        Expr *Base = OrigLHS;
+        const Type* BaseType = Base->getType().getTypePtrOrNull();
+        if (BaseType && Tok.is(tok::l_paren) &&
+            (BaseType->isFunctionType() ||
+             BaseType->isSpecificPlaceholderType(BuiltinType::BoundMember))) {
+          Diag(OpLoc, diag::err_function_is_not_record)
+              << OpKind << Base->getSourceRange()
+              << FixItHint::CreateRemoval(OpLoc);
+          return ParsePostfixExpressionSuffix(Base);
+        }
+
+        LHS = Actions.ActOnStartCXXMemberReference(getCurScope(), Base,
+                                                   OpLoc, OpKind, ObjectType,
+                                                   MayBePseudoDestructor);
+        if (LHS.isInvalid())
+          break;
+
+        ParseOptionalCXXScopeSpecifier(SS, ObjectType,
+                                       /*EnteringContext=*/false,
+                                       &MayBePseudoDestructor);
+        if (SS.isNotEmpty())
+          ObjectType = nullptr;
+      }
+
+      if (Tok.is(tok::code_completion)) {
+        tok::TokenKind CorrectedOpKind =
+            OpKind == tok::arrow ? tok::period : tok::arrow;
+        ExprResult CorrectedLHS(/*Invalid=*/true);
+        if (getLangOpts().CPlusPlus && OrigLHS) {
+          // FIXME: Creating a TentativeAnalysisScope from outside Sema is a
+          // hack.
+          Sema::TentativeAnalysisScope Trap(Actions);
+          CorrectedLHS = Actions.ActOnStartCXXMemberReference(
+              getCurScope(), OrigLHS, OpLoc, CorrectedOpKind, ObjectType,
+              MayBePseudoDestructor);
+        }
+
+        Expr *Base = LHS.get();
+        Expr *CorrectedBase = CorrectedLHS.get();
+        if (!CorrectedBase && !getLangOpts().CPlusPlus)
+          CorrectedBase = Base;
+
+        // Code completion for a member access expression.
+        Actions.CodeCompleteMemberReferenceExpr(
+            getCurScope(), Base, CorrectedBase, OpLoc, OpKind == tok::arrow,
+            Base && ExprStatementTokLoc == Base->getBeginLoc(),
+            PreferredType.get(Tok.getLocation()));
+
+        cutOffParsing();
+        return ExprError();
+      }
+
+      if (MayBePseudoDestructor && !LHS.isInvalid()) {
+        LHS = ParseCXXPseudoDestructor(LHS.get(), OpLoc, OpKind, SS,
+                                       ObjectType);
+        break;
+      }
+
+      // Either the action has told us that this cannot be a
+      // pseudo-destructor expression (based on the type of base
+      // expression), or we didn't see a '~' in the right place. We
+      // can still parse a destructor name here, but in that case it
+      // names a real destructor.
+      // Allow explicit constructor calls in Microsoft mode.
+      // FIXME: Add support for explicit call of template constructor.
+      SourceLocation TemplateKWLoc;
+      UnqualifiedId Name;
+      if (getLangOpts().ObjC && OpKind == tok::period &&
+          Tok.is(tok::kw_class)) {
+        // Objective-C++:
+        //   After a '.' in a member access expression, treat the keyword
+        //   'class' as if it were an identifier.
+        //
+        // This hack allows property access to the 'class' method because it is
+        // such a common method name. For other C++ keywords that are
+        // Objective-C method names, one must use the message send syntax.
+        IdentifierInfo *Id = Tok.getIdentifierInfo();
+        SourceLocation Loc = ConsumeToken();
+        Name.setIdentifier(Id, Loc);
+      } else if (ParseUnqualifiedId(SS,
+                                    /*EnteringContext=*/false,
+                                    /*AllowDestructorName=*/true,
+                                    /*AllowConstructorName=*/
+                                    getLangOpts().MicrosoftExt &&
+                                        SS.isNotEmpty(),
+                                    /*AllowDeductionGuide=*/false,
+                                    ObjectType, &TemplateKWLoc, Name)) {
+        (void)Actions.CorrectDelayedTyposInExpr(LHS);
+        LHS = ExprError();
+      }
+
+      if (!LHS.isInvalid())
+        LHS = Actions.ActOnMemberAccessExpr(getCurScope(), LHS.get(), OpLoc,
+                                            OpKind, SS, TemplateKWLoc, Name,
+                                 CurParsedObjCImpl ? CurParsedObjCImpl->Dcl
+                                                   : nullptr);
+      if (!LHS.isInvalid() && Tok.is(tok::less))
+        checkPotentialAngleBracket(LHS);
+      break;
+    }
+    case tok::plusplus:    // postfix-expression: postfix-expression '++'
+    case tok::minusminus:  // postfix-expression: postfix-expression '--'
+      if (!LHS.isInvalid()) {
+        LHS = Actions.ActOnPostfixUnaryOp(getCurScope(), Tok.getLocation(),
+                                          Tok.getKind(), LHS.get());
+      }
+      ConsumeToken();
+      break;
+    }
+  }
+}
+
+/// ParseExprAfterUnaryExprOrTypeTrait - We parsed a typeof/sizeof/alignof/
+/// vec_step and we are at the start of an expression or a parenthesized
+/// type-id. OpTok is the operand token (typeof/sizeof/alignof). Returns the
+/// expression (isCastExpr == false) or the type (isCastExpr == true).
+///
+/// \verbatim
+///       unary-expression:  [C99 6.5.3]
+///         'sizeof' unary-expression
+///         'sizeof' '(' type-name ')'
+/// [GNU]   '__alignof' unary-expression
+/// [GNU]   '__alignof' '(' type-name ')'
+/// [C11]   '_Alignof' '(' type-name ')'
+/// [C++0x] 'alignof' '(' type-id ')'
+///
+/// [GNU]   typeof-specifier:
+///           typeof ( expressions )
+///           typeof ( type-name )
+/// [GNU/C++] typeof unary-expression
+///
+/// [OpenCL 1.1 6.11.12] vec_step built-in function:
+///           vec_step ( expressions )
+///           vec_step ( type-name )
+/// \endverbatim
+ExprResult
+Parser::ParseExprAfterUnaryExprOrTypeTrait(const Token &OpTok,
+                                           bool &isCastExpr,
+                                           ParsedType &CastTy,
+                                           SourceRange &CastRange) {
+
+  assert(OpTok.isOneOf(tok::kw_typeof, tok::kw_sizeof, tok::kw___alignof,
+                       tok::kw_alignof, tok::kw__Alignof, tok::kw_vec_step,
+                       tok::kw___builtin_omp_required_simd_align) &&
+         "Not a typeof/sizeof/alignof/vec_step expression!");
+
+  ExprResult Operand;
+
+  // If the operand doesn't start with an '(', it must be an expression.
+  if (Tok.isNot(tok::l_paren)) {
+    // If construct allows a form without parenthesis, user may forget to put
+    // pathenthesis around type name.
+    if (OpTok.isOneOf(tok::kw_sizeof, tok::kw___alignof, tok::kw_alignof,
+                      tok::kw__Alignof)) {
+      if (isTypeIdUnambiguously()) {
+        DeclSpec DS(AttrFactory);
+        ParseSpecifierQualifierList(DS);
+        Declarator DeclaratorInfo(DS, DeclaratorContext::TypeNameContext);
+        ParseDeclarator(DeclaratorInfo);
+
+        SourceLocation LParenLoc = PP.getLocForEndOfToken(OpTok.getLocation());
+        SourceLocation RParenLoc = PP.getLocForEndOfToken(PrevTokLocation);
+        Diag(LParenLoc, diag::err_expected_parentheses_around_typename)
+          << OpTok.getName()
+          << FixItHint::CreateInsertion(LParenLoc, "(")
+          << FixItHint::CreateInsertion(RParenLoc, ")");
+        isCastExpr = true;
+        return ExprEmpty();
+      }
+    }
+
+    isCastExpr = false;
+    if (OpTok.is(tok::kw_typeof) && !getLangOpts().CPlusPlus) {
+      Diag(Tok, diag::err_expected_after) << OpTok.getIdentifierInfo()
+                                          << tok::l_paren;
+      return ExprError();
+    }
+
+    Operand = ParseCastExpression(UnaryExprOnly);
+  } else {
+    // If it starts with a '(', we know that it is either a parenthesized
+    // type-name, or it is a unary-expression that starts with a compound
+    // literal, or starts with a primary-expression that is a parenthesized
+    // expression.
+    ParenParseOption ExprType = CastExpr;
+    SourceLocation LParenLoc = Tok.getLocation(), RParenLoc;
+
+    Operand = ParseParenExpression(ExprType, true/*stopIfCastExpr*/,
+                                   false, CastTy, RParenLoc);
+    CastRange = SourceRange(LParenLoc, RParenLoc);
+
+    // If ParseParenExpression parsed a '(typename)' sequence only, then this is
+    // a type.
+    if (ExprType == CastExpr) {
+      isCastExpr = true;
+      return ExprEmpty();
+    }
+
+    if (getLangOpts().CPlusPlus || OpTok.isNot(tok::kw_typeof)) {
+      // GNU typeof in C requires the expression to be parenthesized. Not so for
+      // sizeof/alignof or in C++. Therefore, the parenthesized expression is
+      // the start of a unary-expression, but doesn't include any postfix
+      // pieces. Parse these now if present.
+      if (!Operand.isInvalid())
+        Operand = ParsePostfixExpressionSuffix(Operand.get());
+    }
+  }
+
+  // If we get here, the operand to the typeof/sizeof/alignof was an expression.
+  isCastExpr = false;
+  return Operand;
+}
+
+
+/// Parse a sizeof or alignof expression.
+///
+/// \verbatim
+///       unary-expression:  [C99 6.5.3]
+///         'sizeof' unary-expression
+///         'sizeof' '(' type-name ')'
+/// [C++11] 'sizeof' '...' '(' identifier ')'
+/// [GNU]   '__alignof' unary-expression
+/// [GNU]   '__alignof' '(' type-name ')'
+/// [C11]   '_Alignof' '(' type-name ')'
+/// [C++11] 'alignof' '(' type-id ')'
+/// \endverbatim
+ExprResult Parser::ParseUnaryExprOrTypeTraitExpression() {
+  assert(Tok.isOneOf(tok::kw_sizeof, tok::kw___alignof, tok::kw_alignof,
+                     tok::kw__Alignof, tok::kw_vec_step,
+                     tok::kw___builtin_omp_required_simd_align) &&
+         "Not a sizeof/alignof/vec_step expression!");
+  Token OpTok = Tok;
+  ConsumeToken();
+
+  // [C++11] 'sizeof' '...' '(' identifier ')'
+  if (Tok.is(tok::ellipsis) && OpTok.is(tok::kw_sizeof)) {
+    SourceLocation EllipsisLoc = ConsumeToken();
+    SourceLocation LParenLoc, RParenLoc;
+    IdentifierInfo *Name = nullptr;
+    SourceLocation NameLoc;
+    if (Tok.is(tok::l_paren)) {
+      BalancedDelimiterTracker T(*this, tok::l_paren);
+      T.consumeOpen();
+      LParenLoc = T.getOpenLocation();
+      if (Tok.is(tok::identifier)) {
+        Name = Tok.getIdentifierInfo();
+        NameLoc = ConsumeToken();
+        T.consumeClose();
+        RParenLoc = T.getCloseLocation();
+        if (RParenLoc.isInvalid())
+          RParenLoc = PP.getLocForEndOfToken(NameLoc);
+      } else {
+        Diag(Tok, diag::err_expected_parameter_pack);
+        SkipUntil(tok::r_paren, StopAtSemi);
+      }
+    } else if (Tok.is(tok::identifier)) {
+      Name = Tok.getIdentifierInfo();
+      NameLoc = ConsumeToken();
+      LParenLoc = PP.getLocForEndOfToken(EllipsisLoc);
+      RParenLoc = PP.getLocForEndOfToken(NameLoc);
+      Diag(LParenLoc, diag::err_paren_sizeof_parameter_pack)
+        << Name
+        << FixItHint::CreateInsertion(LParenLoc, "(")
+        << FixItHint::CreateInsertion(RParenLoc, ")");
+    } else {
+      Diag(Tok, diag::err_sizeof_parameter_pack);
+    }
+
+    if (!Name)
+      return ExprError();
+
+    EnterExpressionEvaluationContext Unevaluated(
+        Actions, Sema::ExpressionEvaluationContext::Unevaluated,
+        Sema::ReuseLambdaContextDecl);
+
+    return Actions.ActOnSizeofParameterPackExpr(getCurScope(),
+                                                OpTok.getLocation(),
+                                                *Name, NameLoc,
+                                                RParenLoc);
+  }
+
+  if (OpTok.isOneOf(tok::kw_alignof, tok::kw__Alignof))
+    Diag(OpTok, diag::warn_cxx98_compat_alignof);
+
+  EnterExpressionEvaluationContext Unevaluated(
+      Actions, Sema::ExpressionEvaluationContext::Unevaluated,
+      Sema::ReuseLambdaContextDecl);
+
+  bool isCastExpr;
+  ParsedType CastTy;
+  SourceRange CastRange;
+  ExprResult Operand = ParseExprAfterUnaryExprOrTypeTrait(OpTok,
+                                                          isCastExpr,
+                                                          CastTy,
+                                                          CastRange);
+
+  UnaryExprOrTypeTrait ExprKind = UETT_SizeOf;
+  if (OpTok.isOneOf(tok::kw_alignof, tok::kw__Alignof))
+    ExprKind = UETT_AlignOf;
+  else if (OpTok.is(tok::kw___alignof))
+    ExprKind = UETT_PreferredAlignOf;
+  else if (OpTok.is(tok::kw_vec_step))
+    ExprKind = UETT_VecStep;
+  else if (OpTok.is(tok::kw___builtin_omp_required_simd_align))
+    ExprKind = UETT_OpenMPRequiredSimdAlign;
+
+  if (isCastExpr)
+    return Actions.ActOnUnaryExprOrTypeTraitExpr(OpTok.getLocation(),
+                                                 ExprKind,
+                                                 /*IsType=*/true,
+                                                 CastTy.getAsOpaquePtr(),
+                                                 CastRange);
+
+  if (OpTok.isOneOf(tok::kw_alignof, tok::kw__Alignof))
+    Diag(OpTok, diag::ext_alignof_expr) << OpTok.getIdentifierInfo();
+
+  // If we get here, the operand to the sizeof/alignof was an expression.
+  if (!Operand.isInvalid())
+    Operand = Actions.ActOnUnaryExprOrTypeTraitExpr(OpTok.getLocation(),
+                                                    ExprKind,
+                                                    /*IsType=*/false,
+                                                    Operand.get(),
+                                                    CastRange);
+  return Operand;
+}
+
+/// ParseBuiltinPrimaryExpression
+///
+/// \verbatim
+///       primary-expression: [C99 6.5.1]
+/// [GNU]   '__builtin_va_arg' '(' assignment-expression ',' type-name ')'
+/// [GNU]   '__builtin_offsetof' '(' type-name ',' offsetof-member-designator')'
+/// [GNU]   '__builtin_choose_expr' '(' assign-expr ',' assign-expr ','
+///                                     assign-expr ')'
+/// [GNU]   '__builtin_types_compatible_p' '(' type-name ',' type-name ')'
+/// [GNU]   '__builtin_FILE' '(' ')'
+/// [GNU]   '__builtin_FUNCTION' '(' ')'
+/// [GNU]   '__builtin_LINE' '(' ')'
+/// [CLANG] '__builtin_COLUMN' '(' ')'
+/// [OCL]   '__builtin_astype' '(' assignment-expression ',' type-name ')'
+///
+/// [GNU] offsetof-member-designator:
+/// [GNU]   identifier
+/// [GNU]   offsetof-member-designator '.' identifier
+/// [GNU]   offsetof-member-designator '[' expression ']'
+/// \endverbatim
+ExprResult Parser::ParseBuiltinPrimaryExpression() {
+  ExprResult Res;
+  const IdentifierInfo *BuiltinII = Tok.getIdentifierInfo();
+
+  tok::TokenKind T = Tok.getKind();
+  SourceLocation StartLoc = ConsumeToken();   // Eat the builtin identifier.
+
+  // All of these start with an open paren.
+  if (Tok.isNot(tok::l_paren))
+    return ExprError(Diag(Tok, diag::err_expected_after) << BuiltinII
+                                                         << tok::l_paren);
+
+  BalancedDelimiterTracker PT(*this, tok::l_paren);
+  PT.consumeOpen();
+
+  // TODO: Build AST.
+
+  switch (T) {
+  default: llvm_unreachable("Not a builtin primary expression!");
+  case tok::kw___builtin_va_arg: {
+    ExprResult Expr(ParseAssignmentExpression());
+
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      Expr = ExprError();
+    }
+
+    TypeResult Ty = ParseTypeName();
+
+    if (Tok.isNot(tok::r_paren)) {
+      Diag(Tok, diag::err_expected) << tok::r_paren;
+      Expr = ExprError();
+    }
+
+    if (Expr.isInvalid() || Ty.isInvalid())
+      Res = ExprError();
+    else
+      Res = Actions.ActOnVAArg(StartLoc, Expr.get(), Ty.get(), ConsumeParen());
+    break;
+  }
+  case tok::kw___builtin_offsetof: {
+    SourceLocation TypeLoc = Tok.getLocation();
+    TypeResult Ty = ParseTypeName();
+    if (Ty.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    // We must have at least one identifier here.
+    if (Tok.isNot(tok::identifier)) {
+      Diag(Tok, diag::err_expected) << tok::identifier;
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    // Keep track of the various subcomponents we see.
+    SmallVector<Sema::OffsetOfComponent, 4> Comps;
+
+    Comps.push_back(Sema::OffsetOfComponent());
+    Comps.back().isBrackets = false;
+    Comps.back().U.IdentInfo = Tok.getIdentifierInfo();
+    Comps.back().LocStart = Comps.back().LocEnd = ConsumeToken();
+
+    // FIXME: This loop leaks the index expressions on error.
+    while (1) {
+      if (Tok.is(tok::period)) {
+        // offsetof-member-designator: offsetof-member-designator '.' identifier
+        Comps.push_back(Sema::OffsetOfComponent());
+        Comps.back().isBrackets = false;
+        Comps.back().LocStart = ConsumeToken();
+
+        if (Tok.isNot(tok::identifier)) {
+          Diag(Tok, diag::err_expected) << tok::identifier;
+          SkipUntil(tok::r_paren, StopAtSemi);
+          return ExprError();
+        }
+        Comps.back().U.IdentInfo = Tok.getIdentifierInfo();
+        Comps.back().LocEnd = ConsumeToken();
+
+      } else if (Tok.is(tok::l_square)) {
+        if (CheckProhibitedCXX11Attribute())
+          return ExprError();
+
+        // offsetof-member-designator: offsetof-member-design '[' expression ']'
+        Comps.push_back(Sema::OffsetOfComponent());
+        Comps.back().isBrackets = true;
+        BalancedDelimiterTracker ST(*this, tok::l_square);
+        ST.consumeOpen();
+        Comps.back().LocStart = ST.getOpenLocation();
+        Res = ParseExpression();
+        if (Res.isInvalid()) {
+          SkipUntil(tok::r_paren, StopAtSemi);
+          return Res;
+        }
+        Comps.back().U.E = Res.get();
+
+        ST.consumeClose();
+        Comps.back().LocEnd = ST.getCloseLocation();
+      } else {
+        if (Tok.isNot(tok::r_paren)) {
+          PT.consumeClose();
+          Res = ExprError();
+        } else if (Ty.isInvalid()) {
+          Res = ExprError();
+        } else {
+          PT.consumeClose();
+          Res = Actions.ActOnBuiltinOffsetOf(getCurScope(), StartLoc, TypeLoc,
+                                             Ty.get(), Comps,
+                                             PT.getCloseLocation());
+        }
+        break;
+      }
+    }
+    break;
+  }
+  case tok::kw___builtin_choose_expr: {
+    ExprResult Cond(ParseAssignmentExpression());
+    if (Cond.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return Cond;
+    }
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    ExprResult Expr1(ParseAssignmentExpression());
+    if (Expr1.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return Expr1;
+    }
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    ExprResult Expr2(ParseAssignmentExpression());
+    if (Expr2.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return Expr2;
+    }
+    if (Tok.isNot(tok::r_paren)) {
+      Diag(Tok, diag::err_expected) << tok::r_paren;
+      return ExprError();
+    }
+    Res = Actions.ActOnChooseExpr(StartLoc, Cond.get(), Expr1.get(),
+                                  Expr2.get(), ConsumeParen());
+    break;
+  }
+  case tok::kw___builtin_astype: {
+    // The first argument is an expression to be converted, followed by a comma.
+    ExprResult Expr(ParseAssignmentExpression());
+    if (Expr.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    // Second argument is the type to bitcast to.
+    TypeResult DestTy = ParseTypeName();
+    if (DestTy.isInvalid())
+      return ExprError();
+
+    // Attempt to consume the r-paren.
+    if (Tok.isNot(tok::r_paren)) {
+      Diag(Tok, diag::err_expected) << tok::r_paren;
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    Res = Actions.ActOnAsTypeExpr(Expr.get(), DestTy.get(), StartLoc,
+                                  ConsumeParen());
+    break;
+  }
+  case tok::kw___builtin_convertvector: {
+    // The first argument is an expression to be converted, followed by a comma.
+    ExprResult Expr(ParseAssignmentExpression());
+    if (Expr.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    if (ExpectAndConsume(tok::comma)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    // Second argument is the type to bitcast to.
+    TypeResult DestTy = ParseTypeName();
+    if (DestTy.isInvalid())
+      return ExprError();
+
+    // Attempt to consume the r-paren.
+    if (Tok.isNot(tok::r_paren)) {
+      Diag(Tok, diag::err_expected) << tok::r_paren;
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    Res = Actions.ActOnConvertVectorExpr(Expr.get(), DestTy.get(), StartLoc,
+                                         ConsumeParen());
+    break;
+  }
+  case tok::kw___builtin_COLUMN:
+  case tok::kw___builtin_FILE:
+  case tok::kw___builtin_FUNCTION:
+  case tok::kw___builtin_LINE: {
+    // Attempt to consume the r-paren.
+    if (Tok.isNot(tok::r_paren)) {
+      Diag(Tok, diag::err_expected) << tok::r_paren;
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+    SourceLocExpr::IdentKind Kind = [&] {
+      switch (T) {
+      case tok::kw___builtin_FILE:
+        return SourceLocExpr::File;
+      case tok::kw___builtin_FUNCTION:
+        return SourceLocExpr::Function;
+      case tok::kw___builtin_LINE:
+        return SourceLocExpr::Line;
+      case tok::kw___builtin_COLUMN:
+        return SourceLocExpr::Column;
+      default:
+        llvm_unreachable("invalid keyword");
+      }
+    }();
+    Res = Actions.ActOnSourceLocExpr(Kind, StartLoc, ConsumeParen());
+    break;
+  }
+  }
+
+  if (Res.isInvalid())
+    return ExprError();
+
+  // These can be followed by postfix-expr pieces because they are
+  // primary-expressions.
+  return ParsePostfixExpressionSuffix(Res.get());
+}
+
+/// ParseParenExpression - This parses the unit that starts with a '(' token,
+/// based on what is allowed by ExprType.  The actual thing parsed is returned
+/// in ExprType. If stopIfCastExpr is true, it will only return the parsed type,
+/// not the parsed cast-expression.
+///
+/// \verbatim
+///       primary-expression: [C99 6.5.1]
+///         '(' expression ')'
+/// [GNU]   '(' compound-statement ')'      (if !ParenExprOnly)
+///       postfix-expression: [C99 6.5.2]
+///         '(' type-name ')' '{' initializer-list '}'
+///         '(' type-name ')' '{' initializer-list ',' '}'
+///       cast-expression: [C99 6.5.4]
+///         '(' type-name ')' cast-expression
+/// [ARC]   bridged-cast-expression
+/// [ARC] bridged-cast-expression:
+///         (__bridge type-name) cast-expression
+///         (__bridge_transfer type-name) cast-expression
+///         (__bridge_retained type-name) cast-expression
+///       fold-expression: [C++1z]
+///         '(' cast-expression fold-operator '...' ')'
+///         '(' '...' fold-operator cast-expression ')'
+///         '(' cast-expression fold-operator '...'
+///                 fold-operator cast-expression ')'
+/// \endverbatim
+ExprResult
+Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
+                             bool isTypeCast, ParsedType &CastTy,
+                             SourceLocation &RParenLoc) {
+  assert(Tok.is(tok::l_paren) && "Not a paren expr!");
+  ColonProtectionRAIIObject ColonProtection(*this, false);
+  BalancedDelimiterTracker T(*this, tok::l_paren);
+  if (T.consumeOpen())
+    return ExprError();
+  SourceLocation OpenLoc = T.getOpenLocation();
+
+  PreferredType.enterParenExpr(Tok.getLocation(), OpenLoc);
+
+  ExprResult Result(true);
+  bool isAmbiguousTypeId;
+  CastTy = nullptr;
+
+  if (Tok.is(tok::code_completion)) {
+    Actions.CodeCompleteExpression(
+        getCurScope(), PreferredType.get(Tok.getLocation()),
+        /*IsParenthesized=*/ExprType >= CompoundLiteral);
+    cutOffParsing();
+    return ExprError();
+  }
+
+  // Diagnose use of bridge casts in non-arc mode.
+  bool BridgeCast = (getLangOpts().ObjC &&
+                     Tok.isOneOf(tok::kw___bridge,
+                                 tok::kw___bridge_transfer,
+                                 tok::kw___bridge_retained,
+                                 tok::kw___bridge_retain));
+  if (BridgeCast && !getLangOpts().ObjCAutoRefCount) {
+    if (!TryConsumeToken(tok::kw___bridge)) {
+      StringRef BridgeCastName = Tok.getName();
+      SourceLocation BridgeKeywordLoc = ConsumeToken();
+      if (!PP.getSourceManager().isInSystemHeader(BridgeKeywordLoc))
+        Diag(BridgeKeywordLoc, diag::warn_arc_bridge_cast_nonarc)
+          << BridgeCastName
+          << FixItHint::CreateReplacement(BridgeKeywordLoc, "");
+    }
+    BridgeCast = false;
+  }
+
+  // None of these cases should fall through with an invalid Result
+  // unless they've already reported an error.
+  if (ExprType >= CompoundStmt && Tok.is(tok::l_brace)) {
+    Diag(Tok, diag::ext_gnu_statement_expr);
+
+    if (!getCurScope()->getFnParent() && !getCurScope()->getBlockParent()) {
+      Result = ExprError(Diag(OpenLoc, diag::err_stmtexpr_file_scope));
+    } else {
+      // Find the nearest non-record decl context. Variables declared in a
+      // statement expression behave as if they were declared in the enclosing
+      // function, block, or other code construct.
+      DeclContext *CodeDC = Actions.CurContext;
+      while (CodeDC->isRecord() || isa<EnumDecl>(CodeDC)) {
+        CodeDC = CodeDC->getParent();
+        assert(CodeDC && !CodeDC->isFileContext() &&
+               "statement expr not in code context");
+      }
+      Sema::ContextRAII SavedContext(Actions, CodeDC, /*NewThisContext=*/false);
+
+      Actions.ActOnStartStmtExpr();
+
+      StmtResult Stmt(ParseCompoundStatement(true));
+      ExprType = CompoundStmt;
+
+      // If the substmt parsed correctly, build the AST node.
+      if (!Stmt.isInvalid()) {
+        Result = Actions.ActOnStmtExpr(OpenLoc, Stmt.get(), Tok.getLocation());
+      } else {
+        Actions.ActOnStmtExprError();
+      }
+    }
+  } else if (ExprType >= CompoundLiteral && BridgeCast) {
+    tok::TokenKind tokenKind = Tok.getKind();
+    SourceLocation BridgeKeywordLoc = ConsumeToken();
+
+    // Parse an Objective-C ARC ownership cast expression.
+    ObjCBridgeCastKind Kind;
+    if (tokenKind == tok::kw___bridge)
+      Kind = OBC_Bridge;
+    else if (tokenKind == tok::kw___bridge_transfer)
+      Kind = OBC_BridgeTransfer;
+    else if (tokenKind == tok::kw___bridge_retained)
+      Kind = OBC_BridgeRetained;
+    else {
+      // As a hopefully temporary workaround, allow __bridge_retain as
+      // a synonym for __bridge_retained, but only in system headers.
+      assert(tokenKind == tok::kw___bridge_retain);
+      Kind = OBC_BridgeRetained;
+      if (!PP.getSourceManager().isInSystemHeader(BridgeKeywordLoc))
+        Diag(BridgeKeywordLoc, diag::err_arc_bridge_retain)
+          << FixItHint::CreateReplacement(BridgeKeywordLoc,
+                                          "__bridge_retained");
+    }
+
+    TypeResult Ty = ParseTypeName();
+    T.consumeClose();
+    ColonProtection.restore();
+    RParenLoc = T.getCloseLocation();
+
+    PreferredType.enterTypeCast(Tok.getLocation(), Ty.get().get());
+    ExprResult SubExpr = ParseCastExpression(AnyCastExpr);
+    
+    if (Ty.isInvalid() || SubExpr.isInvalid())
+      return ExprError();
+
+    return Actions.ActOnObjCBridgedCast(getCurScope(), OpenLoc, Kind,
+                                        BridgeKeywordLoc, Ty.get(),
+                                        RParenLoc, SubExpr.get());
+  } else if (ExprType >= CompoundLiteral &&
+             isTypeIdInParens(isAmbiguousTypeId)) {
+
+    // Otherwise, this is a compound literal expression or cast expression.
+
+    // In C++, if the type-id is ambiguous we disambiguate based on context.
+    // If stopIfCastExpr is true the context is a typeof/sizeof/alignof
+    // in which case we should treat it as type-id.
+    // if stopIfCastExpr is false, we need to determine the context past the
+    // parens, so we defer to ParseCXXAmbiguousParenExpression for that.
+    if (isAmbiguousTypeId && !stopIfCastExpr) {
+      ExprResult res = ParseCXXAmbiguousParenExpression(ExprType, CastTy, T,
+                                                        ColonProtection);
+      RParenLoc = T.getCloseLocation();
+      return res;
+    }
+
+    // Parse the type declarator.
+    DeclSpec DS(AttrFactory);
+    ParseSpecifierQualifierList(DS);
+    Declarator DeclaratorInfo(DS, DeclaratorContext::TypeNameContext);
+    ParseDeclarator(DeclaratorInfo);
+
+    // If our type is followed by an identifier and either ':' or ']', then
+    // this is probably an Objective-C message send where the leading '[' is
+    // missing. Recover as if that were the case.
+    if (!DeclaratorInfo.isInvalidType() && Tok.is(tok::identifier) &&
+        !InMessageExpression && getLangOpts().ObjC &&
+        (NextToken().is(tok::colon) || NextToken().is(tok::r_square))) {
+      TypeResult Ty;
+      {
+        InMessageExpressionRAIIObject InMessage(*this, false);
+        Ty = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
+      }
+      Result = ParseObjCMessageExpressionBody(SourceLocation(),
+                                              SourceLocation(),
+                                              Ty.get(), nullptr);
+    } else {
+      // Match the ')'.
+      T.consumeClose();
+      ColonProtection.restore();
+      RParenLoc = T.getCloseLocation();
+      if (Tok.is(tok::l_brace)) {
+        ExprType = CompoundLiteral;
+        TypeResult Ty;
+        {
+          InMessageExpressionRAIIObject InMessage(*this, false);
+          Ty = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
+        }
+        return ParseCompoundLiteralExpression(Ty.get(), OpenLoc, RParenLoc);
+      }
+
+      if (Tok.is(tok::l_paren)) {
+        // This could be OpenCL vector Literals
+        if (getLangOpts().OpenCL)
+        {
+          TypeResult Ty;
+          {
+            InMessageExpressionRAIIObject InMessage(*this, false);
+            Ty = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
+          }
+          if(Ty.isInvalid())
+          {
+             return ExprError();
+          }
+          QualType QT = Ty.get().get().getCanonicalType();
+          if (QT->isVectorType())
+          {
+            // We parsed '(' vector-type-name ')' followed by '('
+
+            // Parse the cast-expression that follows it next.
+            // isVectorLiteral = true will make sure we don't parse any
+            // Postfix expression yet
+            Result = ParseCastExpression(/*isUnaryExpression=*/AnyCastExpr,
+                                         /*isAddressOfOperand=*/false,
+                                         /*isTypeCast=*/IsTypeCast,
+                                         /*isVectorLiteral=*/true);
+
+            if (!Result.isInvalid()) {
+              Result = Actions.ActOnCastExpr(getCurScope(), OpenLoc,
+                                             DeclaratorInfo, CastTy,
+                                             RParenLoc, Result.get());
+            }
+
+            // After we performed the cast we can check for postfix-expr pieces.
+            if (!Result.isInvalid()) {
+              Result = ParsePostfixExpressionSuffix(Result);
+            }
+
+            return Result;
+          }
+        }
+      }
+
+      if (ExprType == CastExpr) {
+        // We parsed '(' type-name ')' and the thing after it wasn't a '{'.
+
+        if (DeclaratorInfo.isInvalidType())
+          return ExprError();
+
+        // Note that this doesn't parse the subsequent cast-expression, it just
+        // returns the parsed type to the callee.
+        if (stopIfCastExpr) {
+          TypeResult Ty;
+          {
+            InMessageExpressionRAIIObject InMessage(*this, false);
+            Ty = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo);
+          }
+          CastTy = Ty.get();
+          return ExprResult();
+        }
+
+        // Reject the cast of super idiom in ObjC.
+        if (Tok.is(tok::identifier) && getLangOpts().ObjC &&
+            Tok.getIdentifierInfo() == Ident_super &&
+            getCurScope()->isInObjcMethodScope() &&
+            GetLookAheadToken(1).isNot(tok::period)) {
+          Diag(Tok.getLocation(), diag::err_illegal_super_cast)
+            << SourceRange(OpenLoc, RParenLoc);
+          return ExprError();
+        }
+
+        PreferredType.enterTypeCast(Tok.getLocation(), CastTy.get());
+        // Parse the cast-expression that follows it next.
+        // TODO: For cast expression with CastTy.
+        Result = ParseCastExpression(/*isUnaryExpression=*/AnyCastExpr,
+                                     /*isAddressOfOperand=*/false,
+                                     /*isTypeCast=*/IsTypeCast);
+        if (!Result.isInvalid()) {
+          Result = Actions.ActOnCastExpr(getCurScope(), OpenLoc,
+                                         DeclaratorInfo, CastTy,
+                                         RParenLoc, Result.get());
+        }
+        return Result;
+      }
+
+      Diag(Tok, diag::err_expected_lbrace_in_compound_literal);
+      return ExprError();
+    }
+  } else if (ExprType >= FoldExpr && Tok.is(tok::ellipsis) &&
+             isFoldOperator(NextToken().getKind())) {
+    ExprType = FoldExpr;
+    return ParseFoldExpression(ExprResult(), T);
+  } else if (isTypeCast) {
+    // Parse the expression-list.
+    InMessageExpressionRAIIObject InMessage(*this, false);
+
+    ExprVector ArgExprs;
+    CommaLocsTy CommaLocs;
+
+    if (!ParseSimpleExpressionList(ArgExprs, CommaLocs)) {
+      // FIXME: If we ever support comma expressions as operands to
+      // fold-expressions, we'll need to allow multiple ArgExprs here.
+      if (ExprType >= FoldExpr && ArgExprs.size() == 1 &&
+          isFoldOperator(Tok.getKind()) && NextToken().is(tok::ellipsis)) {
+        ExprType = FoldExpr;
+        return ParseFoldExpression(ArgExprs[0], T);
+      }
+
+      ExprType = SimpleExpr;
+      Result = Actions.ActOnParenListExpr(OpenLoc, Tok.getLocation(),
+                                          ArgExprs);
+    }
+  } else {
+    InMessageExpressionRAIIObject InMessage(*this, false);
+
+    Result = ParseExpression(MaybeTypeCast);
+    if (!getLangOpts().CPlusPlus && MaybeTypeCast && Result.isUsable()) {
+      // Correct typos in non-C++ code earlier so that implicit-cast-like
+      // expressions are parsed correctly.
+      Result = Actions.CorrectDelayedTyposInExpr(Result);
+    }
+
+    if (ExprType >= FoldExpr && isFoldOperator(Tok.getKind()) &&
+        NextToken().is(tok::ellipsis)) {
+      ExprType = FoldExpr;
+      return ParseFoldExpression(Result, T);
+    }
+    ExprType = SimpleExpr;
+
+    // Don't build a paren expression unless we actually match a ')'.
+    if (!Result.isInvalid() && Tok.is(tok::r_paren))
+      Result =
+          Actions.ActOnParenExpr(OpenLoc, Tok.getLocation(), Result.get());
+  }
+
+  // Match the ')'.
+  if (Result.isInvalid()) {
+    SkipUntil(tok::r_paren, StopAtSemi);
+    return ExprError();
+  }
+
+  T.consumeClose();
+  RParenLoc = T.getCloseLocation();
+  return Result;
+}
+
+/// ParseCompoundLiteralExpression - We have parsed the parenthesized type-name
+/// and we are at the left brace.
+///
+/// \verbatim
+///       postfix-expression: [C99 6.5.2]
+///         '(' type-name ')' '{' initializer-list '}'
+///         '(' type-name ')' '{' initializer-list ',' '}'
+/// \endverbatim
+ExprResult
+Parser::ParseCompoundLiteralExpression(ParsedType Ty,
+                                       SourceLocation LParenLoc,
+                                       SourceLocation RParenLoc) {
+  assert(Tok.is(tok::l_brace) && "Not a compound literal!");
+  if (!getLangOpts().C99)   // Compound literals don't exist in C90.
+    Diag(LParenLoc, diag::ext_c99_compound_literal);
+  ExprResult Result = ParseInitializer();
+  if (!Result.isInvalid() && Ty)
+    return Actions.ActOnCompoundLiteral(LParenLoc, Ty, RParenLoc, Result.get());
+  return Result;
+}
+
+/// ParseStringLiteralExpression - This handles the various token types that
+/// form string literals, and also handles string concatenation [C99 5.1.1.2,
+/// translation phase #6].
+///
+/// \verbatim
+///       primary-expression: [C99 6.5.1]
+///         string-literal
+/// \verbatim
+ExprResult Parser::ParseStringLiteralExpression(bool AllowUserDefinedLiteral) {
+  assert(isTokenStringLiteral() && "Not a string literal!");
+
+  // String concat.  Note that keywords like __func__ and __FUNCTION__ are not
+  // considered to be strings for concatenation purposes.
+  SmallVector<Token, 4> StringToks;
+
+  do {
+    StringToks.push_back(Tok);
+    ConsumeStringToken();
+  } while (isTokenStringLiteral());
+
+  // Pass the set of string tokens, ready for concatenation, to the actions.
+  return Actions.ActOnStringLiteral(StringToks,
+                                    AllowUserDefinedLiteral ? getCurScope()
+                                                            : nullptr);
+}
+
+/// ParseGenericSelectionExpression - Parse a C11 generic-selection
+/// [C11 6.5.1.1].
+///
+/// \verbatim
+///    generic-selection:
+///           _Generic ( assignment-expression , generic-assoc-list )
+///    generic-assoc-list:
+///           generic-association
+///           generic-assoc-list , generic-association
+///    generic-association:
+///           type-name : assignment-expression
+///           default : assignment-expression
+/// \endverbatim
+ExprResult Parser::ParseGenericSelectionExpression() {
+  assert(Tok.is(tok::kw__Generic) && "_Generic keyword expected");
+  if (!getLangOpts().C11)
+    Diag(Tok, diag::ext_c11_feature) << Tok.getName();
+
+  SourceLocation KeyLoc = ConsumeToken();
+  BalancedDelimiterTracker T(*this, tok::l_paren);
+  if (T.expectAndConsume())
+    return ExprError();
+
+  ExprResult ControllingExpr;
+  {
+    // C11 6.5.1.1p3 "The controlling expression of a generic selection is
+    // not evaluated."
+    EnterExpressionEvaluationContext Unevaluated(
+        Actions, Sema::ExpressionEvaluationContext::Unevaluated);
+    ControllingExpr =
+        Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression());
+    if (ControllingExpr.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+  }
+
+  if (ExpectAndConsume(tok::comma)) {
+    SkipUntil(tok::r_paren, StopAtSemi);
+    return ExprError();
+  }
+
+  SourceLocation DefaultLoc;
+  TypeVector Types;
+  ExprVector Exprs;
+  do {
+    ParsedType Ty;
+    if (Tok.is(tok::kw_default)) {
+      // C11 6.5.1.1p2 "A generic selection shall have no more than one default
+      // generic association."
+      if (!DefaultLoc.isInvalid()) {
+        Diag(Tok, diag::err_duplicate_default_assoc);
+        Diag(DefaultLoc, diag::note_previous_default_assoc);
+        SkipUntil(tok::r_paren, StopAtSemi);
+        return ExprError();
+      }
+      DefaultLoc = ConsumeToken();
+      Ty = nullptr;
+    } else {
+      ColonProtectionRAIIObject X(*this);
+      TypeResult TR = ParseTypeName();
+      if (TR.isInvalid()) {
+        SkipUntil(tok::r_paren, StopAtSemi);
+        return ExprError();
+      }
+      Ty = TR.get();
+    }
+    Types.push_back(Ty);
+
+    if (ExpectAndConsume(tok::colon)) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+
+    // FIXME: These expressions should be parsed in a potentially potentially
+    // evaluated context.
+    ExprResult ER(
+        Actions.CorrectDelayedTyposInExpr(ParseAssignmentExpression()));
+    if (ER.isInvalid()) {
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return ExprError();
+    }
+    Exprs.push_back(ER.get());
+  } while (TryConsumeToken(tok::comma));
+
+  T.consumeClose();
+  if (T.getCloseLocation().isInvalid())
+    return ExprError();
+
+  return Actions.ActOnGenericSelectionExpr(KeyLoc, DefaultLoc,
+                                           T.getCloseLocation(),
+                                           ControllingExpr.get(),
+                                           Types, Exprs);
+}
+
+/// Parse A C++1z fold-expression after the opening paren and optional
+/// left-hand-side expression.
+///
+/// \verbatim
+///   fold-expression:
+///       ( cast-expression fold-operator ... )
+///       ( ... fold-operator cast-expression )
+///       ( cast-expression fold-operator ... fold-operator cast-expression )
+ExprResult Parser::ParseFoldExpression(ExprResult LHS,
+                                       BalancedDelimiterTracker &T) {
+  if (LHS.isInvalid()) {
+    T.skipToEnd();
+    return true;
+  }
+
+  tok::TokenKind Kind = tok::unknown;
+  SourceLocation FirstOpLoc;
+  if (LHS.isUsable()) {
+    Kind = Tok.getKind();
+    assert(isFoldOperator(Kind) && "missing fold-operator");
+    FirstOpLoc = ConsumeToken();
+  }
+
+  assert(Tok.is(tok::ellipsis) && "not a fold-expression");
+  SourceLocation EllipsisLoc = ConsumeToken();
+
+  ExprResult RHS;
+  if (Tok.isNot(tok::r_paren)) {
+    if (!isFoldOperator(Tok.getKind()))
+      return Diag(Tok.getLocation(), diag::err_expected_fold_operator);
+
+    if (Kind != tok::unknown && Tok.getKind() != Kind)
+      Diag(Tok.getLocation(), diag::err_fold_operator_mismatch)
+        << SourceRange(FirstOpLoc);
+    Kind = Tok.getKind();
+    ConsumeToken();
+
+    RHS = ParseExpression();
+    if (RHS.isInvalid()) {
+      T.skipToEnd();
+      return true;
+    }
+  }
+
+  Diag(EllipsisLoc, getLangOpts().CPlusPlus17
+                        ? diag::warn_cxx14_compat_fold_expression
+                        : diag::ext_fold_expression);
+
+  T.consumeClose();
+  return Actions.ActOnCXXFoldExpr(T.getOpenLocation(), LHS.get(), Kind,
+                                  EllipsisLoc, RHS.get(), T.getCloseLocation());
+}
+
+/// ParseExpressionList - Used for C/C++ (argument-)expression-list.
+///
+/// \verbatim
+///       argument-expression-list:
+///         assignment-expression
+///         argument-expression-list , assignment-expression
+///
+/// [C++] expression-list:
+/// [C++]   assignment-expression
+/// [C++]   expression-list , assignment-expression
+///
+/// [C++0x] expression-list:
+/// [C++0x]   initializer-list
+///
+/// [C++0x] initializer-list
+/// [C++0x]   initializer-clause ...[opt]
+/// [C++0x]   initializer-list , initializer-clause ...[opt]
+///
+/// [C++0x] initializer-clause:
+/// [C++0x]   assignment-expression
+/// [C++0x]   braced-init-list
+/// \endverbatim
+bool Parser::ParseExpressionList(SmallVectorImpl<Expr *> &Exprs,
+                                 SmallVectorImpl<SourceLocation> &CommaLocs,
+                                 llvm::function_ref<void()> ExpressionStarts) {
+  bool SawError = false;
+  while (1) {
+    if (ExpressionStarts)
+      ExpressionStarts();
+
+    ExprResult Expr;
+    if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
+      Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
+      Expr = ParseBraceInitializer();
+    } else
+      Expr = ParseAssignmentExpression();
+
+    if (Tok.is(tok::ellipsis))
+      Expr = Actions.ActOnPackExpansion(Expr.get(), ConsumeToken());
+    else if (Tok.is(tok::code_completion)) {
+      // There's nothing to suggest in here as we parsed a full expression.
+      // Instead fail and propogate the error since caller might have something
+      // the suggest, e.g. signature help in function call. Note that this is
+      // performed before pushing the \p Expr, so that signature help can report
+      // current argument correctly.
+      SawError = true;
+      cutOffParsing();
+      break;
+    }
+    if (Expr.isInvalid()) {
+      SkipUntil(tok::comma, tok::r_paren, StopBeforeMatch);
+      SawError = true;
+    } else {
+      Exprs.push_back(Expr.get());
+    }
+
+    if (Tok.isNot(tok::comma))
+      break;
+    // Move to the next argument, remember where the comma was.
+    Token Comma = Tok;
+    CommaLocs.push_back(ConsumeToken());
+
+    checkPotentialAngleBracketDelimiter(Comma);
+  }
+  if (SawError) {
+    // Ensure typos get diagnosed when errors were encountered while parsing the
+    // expression list.
+    for (auto &E : Exprs) {
+      ExprResult Expr = Actions.CorrectDelayedTyposInExpr(E);
+      if (Expr.isUsable()) E = Expr.get();
+    }
+  }
+  return SawError;
+}
+
+/// ParseSimpleExpressionList - A simple comma-separated list of expressions,
+/// used for misc language extensions.
+///
+/// \verbatim
+///       simple-expression-list:
+///         assignment-expression
+///         simple-expression-list , assignment-expression
+/// \endverbatim
+bool
+Parser::ParseSimpleExpressionList(SmallVectorImpl<Expr*> &Exprs,
+                                  SmallVectorImpl<SourceLocation> &CommaLocs) {
+  while (1) {
+    ExprResult Expr = ParseAssignmentExpression();
+    if (Expr.isInvalid())
+      return true;
+
+    Exprs.push_back(Expr.get());
+
+    if (Tok.isNot(tok::comma))
+      return false;
+
+    // Move to the next argument, remember where the comma was.
+    Token Comma = Tok;
+    CommaLocs.push_back(ConsumeToken());
+
+    checkPotentialAngleBracketDelimiter(Comma);
+  }
+}
+
+/// ParseBlockId - Parse a block-id, which roughly looks like int (int x).
+///
+/// \verbatim
+/// [clang] block-id:
+/// [clang]   specifier-qualifier-list block-declarator
+/// \endverbatim
+void Parser::ParseBlockId(SourceLocation CaretLoc) {
+  if (Tok.is(tok::code_completion)) {
+    Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Type);
+    return cutOffParsing();
+  }
+
+  // Parse the specifier-qualifier-list piece.
+  DeclSpec DS(AttrFactory);
+  ParseSpecifierQualifierList(DS);
+
+  // Parse the block-declarator.
+  Declarator DeclaratorInfo(DS, DeclaratorContext::BlockLiteralContext);
+  DeclaratorInfo.setFunctionDefinitionKind(FDK_Definition);
+  ParseDeclarator(DeclaratorInfo);
+
+  MaybeParseGNUAttributes(DeclaratorInfo);
+
+  // Inform sema that we are starting a block.
+  Actions.ActOnBlockArguments(CaretLoc, DeclaratorInfo, getCurScope());
+}
+
+/// ParseBlockLiteralExpression - Parse a block literal, which roughly looks
+/// like ^(int x){ return x+1; }
+///
+/// \verbatim
+///         block-literal:
+/// [clang]   '^' block-args[opt] compound-statement
+/// [clang]   '^' block-id compound-statement
+/// [clang] block-args:
+/// [clang]   '(' parameter-list ')'
+/// \endverbatim
+ExprResult Parser::ParseBlockLiteralExpression() {
+  assert(Tok.is(tok::caret) && "block literal starts with ^");
+  SourceLocation CaretLoc = ConsumeToken();
+
+  PrettyStackTraceLoc CrashInfo(PP.getSourceManager(), CaretLoc,
+                                "block literal parsing");
+
+  // Enter a scope to hold everything within the block.  This includes the
+  // argument decls, decls within the compound expression, etc.  This also
+  // allows determining whether a variable reference inside the block is
+  // within or outside of the block.
+  ParseScope BlockScope(this, Scope::BlockScope | Scope::FnScope |
+                                  Scope::CompoundStmtScope | Scope::DeclScope);
+
+  // Inform sema that we are starting a block.
+  Actions.ActOnBlockStart(CaretLoc, getCurScope());
+
+  // Parse the return type if present.
+  DeclSpec DS(AttrFactory);
+  Declarator ParamInfo(DS, DeclaratorContext::BlockLiteralContext);
+  ParamInfo.setFunctionDefinitionKind(FDK_Definition);
+  // FIXME: Since the return type isn't actually parsed, it can't be used to
+  // fill ParamInfo with an initial valid range, so do it manually.
+  ParamInfo.SetSourceRange(SourceRange(Tok.getLocation(), Tok.getLocation()));
+
+  // If this block has arguments, parse them.  There is no ambiguity here with
+  // the expression case, because the expression case requires a parameter list.
+  if (Tok.is(tok::l_paren)) {
+    ParseParenDeclarator(ParamInfo);
+    // Parse the pieces after the identifier as if we had "int(...)".
+    // SetIdentifier sets the source range end, but in this case we're past
+    // that location.
+    SourceLocation Tmp = ParamInfo.getSourceRange().getEnd();
+    ParamInfo.SetIdentifier(nullptr, CaretLoc);
+    ParamInfo.SetRangeEnd(Tmp);
+    if (ParamInfo.isInvalidType()) {
+      // If there was an error parsing the arguments, they may have
+      // tried to use ^(x+y) which requires an argument list.  Just
+      // skip the whole block literal.
+      Actions.ActOnBlockError(CaretLoc, getCurScope());
+      return ExprError();
+    }
+
+    MaybeParseGNUAttributes(ParamInfo);
+
+    // Inform sema that we are starting a block.
+    Actions.ActOnBlockArguments(CaretLoc, ParamInfo, getCurScope());
+  } else if (!Tok.is(tok::l_brace)) {
+    ParseBlockId(CaretLoc);
+  } else {
+    // Otherwise, pretend we saw (void).
+    SourceLocation NoLoc;
+    ParamInfo.AddTypeInfo(
+        DeclaratorChunk::getFunction(/*HasProto=*/true,
+                                     /*IsAmbiguous=*/false,
+                                     /*RParenLoc=*/NoLoc,
+                                     /*ArgInfo=*/nullptr,
+                                     /*NumParams=*/0,
+                                     /*EllipsisLoc=*/NoLoc,
+                                     /*RParenLoc=*/NoLoc,
+                                     /*RefQualifierIsLvalueRef=*/true,
+                                     /*RefQualifierLoc=*/NoLoc,
+                                     /*MutableLoc=*/NoLoc, EST_None,
+                                     /*ESpecRange=*/SourceRange(),
+                                     /*Exceptions=*/nullptr,
+                                     /*ExceptionRanges=*/nullptr,
+                                     /*NumExceptions=*/0,
+                                     /*NoexceptExpr=*/nullptr,
+                                     /*ExceptionSpecTokens=*/nullptr,
+                                     /*DeclsInPrototype=*/None, CaretLoc,
+                                     CaretLoc, ParamInfo),
+        CaretLoc);
+
+    MaybeParseGNUAttributes(ParamInfo);
+
+    // Inform sema that we are starting a block.
+    Actions.ActOnBlockArguments(CaretLoc, ParamInfo, getCurScope());
+  }
+
+
+  ExprResult Result(true);
+  if (!Tok.is(tok::l_brace)) {
+    // Saw something like: ^expr
+    Diag(Tok, diag::err_expected_expression);
+    Actions.ActOnBlockError(CaretLoc, getCurScope());
+    return ExprError();
+  }
+
+  StmtResult Stmt(ParseCompoundStatementBody());
+  BlockScope.Exit();
+  if (!Stmt.isInvalid())
+    Result = Actions.ActOnBlockStmtExpr(CaretLoc, Stmt.get(), getCurScope());
+  else
+    Actions.ActOnBlockError(CaretLoc, getCurScope());
+  return Result;
+}
+
+/// ParseObjCBoolLiteral - This handles the objective-c Boolean literals.
+///
+///         '__objc_yes'
+///         '__objc_no'
+ExprResult Parser::ParseObjCBoolLiteral() {
+  tok::TokenKind Kind = Tok.getKind();
+  return Actions.ActOnObjCBoolLiteral(ConsumeToken(), Kind);
+}
+
+/// Validate availability spec list, emitting diagnostics if necessary. Returns
+/// true if invalid.
+static bool CheckAvailabilitySpecList(Parser &P,
+                                      ArrayRef<AvailabilitySpec> AvailSpecs) {
+  llvm::SmallSet<StringRef, 4> Platforms;
+  bool HasOtherPlatformSpec = false;
+  bool Valid = true;
+  for (const auto &Spec : AvailSpecs) {
+    if (Spec.isOtherPlatformSpec()) {
+      if (HasOtherPlatformSpec) {
+        P.Diag(Spec.getBeginLoc(), diag::err_availability_query_repeated_star);
+        Valid = false;
+      }
+
+      HasOtherPlatformSpec = true;
+      continue;
+    }
+
+    bool Inserted = Platforms.insert(Spec.getPlatform()).second;
+    if (!Inserted) {
+      // Rule out multiple version specs referring to the same platform.
+      // For example, we emit an error for:
+      // @available(macos 10.10, macos 10.11, *)
+      StringRef Platform = Spec.getPlatform();
+      P.Diag(Spec.getBeginLoc(), diag::err_availability_query_repeated_platform)
+          << Spec.getEndLoc() << Platform;
+      Valid = false;
+    }
+  }
+
+  if (!HasOtherPlatformSpec) {
+    SourceLocation InsertWildcardLoc = AvailSpecs.back().getEndLoc();
+    P.Diag(InsertWildcardLoc, diag::err_availability_query_wildcard_required)
+        << FixItHint::CreateInsertion(InsertWildcardLoc, ", *");
+    return true;
+  }
+
+  return !Valid;
+}
+
+/// Parse availability query specification.
+///
+///  availability-spec:
+///     '*'
+///     identifier version-tuple
+Optional<AvailabilitySpec> Parser::ParseAvailabilitySpec() {
+  if (Tok.is(tok::star)) {
+    return AvailabilitySpec(ConsumeToken());
+  } else {
+    // Parse the platform name.
+    if (Tok.is(tok::code_completion)) {
+      Actions.CodeCompleteAvailabilityPlatformName();
+      cutOffParsing();
+      return None;
+    }
+    if (Tok.isNot(tok::identifier)) {
+      Diag(Tok, diag::err_avail_query_expected_platform_name);
+      return None;
+    }
+
+    IdentifierLoc *PlatformIdentifier = ParseIdentifierLoc();
+    SourceRange VersionRange;
+    VersionTuple Version = ParseVersionTuple(VersionRange);
+
+    if (Version.empty())
+      return None;
+
+    StringRef GivenPlatform = PlatformIdentifier->Ident->getName();
+    StringRef Platform =
+        AvailabilityAttr::canonicalizePlatformName(GivenPlatform);
+
+    if (AvailabilityAttr::getPrettyPlatformName(Platform).empty()) {
+      Diag(PlatformIdentifier->Loc,
+           diag::err_avail_query_unrecognized_platform_name)
+          << GivenPlatform;
+      return None;
+    }
+
+    return AvailabilitySpec(Version, Platform, PlatformIdentifier->Loc,
+                            VersionRange.getEnd());
+  }
+}
+
+ExprResult Parser::ParseAvailabilityCheckExpr(SourceLocation BeginLoc) {
+  assert(Tok.is(tok::kw___builtin_available) ||
+         Tok.isObjCAtKeyword(tok::objc_available));
+
+  // Eat the available or __builtin_available.
+  ConsumeToken();
+
+  BalancedDelimiterTracker Parens(*this, tok::l_paren);
+  if (Parens.expectAndConsume())
+    return ExprError();
+
+  SmallVector<AvailabilitySpec, 4> AvailSpecs;
+  bool HasError = false;
+  while (true) {
+    Optional<AvailabilitySpec> Spec = ParseAvailabilitySpec();
+    if (!Spec)
+      HasError = true;
+    else
+      AvailSpecs.push_back(*Spec);
+
+    if (!TryConsumeToken(tok::comma))
+      break;
+  }
+
+  if (HasError) {
+    SkipUntil(tok::r_paren, StopAtSemi);
+    return ExprError();
+  }
+
+  CheckAvailabilitySpecList(*this, AvailSpecs);
+
+  if (Parens.consumeClose())
+    return ExprError();
+
+  return Actions.ActOnObjCAvailabilityCheckExpr(AvailSpecs, BeginLoc,
+                                                Parens.getCloseLocation());
+}