Fix parsing of fold-expressions within a cast expression. We parse the

parenthesized expression a bit differently in this case, just in case the
commas have special meaning.

llvm-svn: 221661

1 files changed, 11 insertions, 5 deletions

diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 6913de9fa19..f4eef811755 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -2203,24 +2203,30 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr,
       Diag(Tok, diag::err_expected_lbrace_in_compound_literal);
       return ExprError();
     }
+  } else if (Tok.is(tok::ellipsis) &&
+             isFoldOperator(NextToken().getKind())) {
+    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 (ArgExprs.size() == 1 && isFoldOperator(Tok.getKind()) &&
+          NextToken().is(tok::ellipsis))
+        return ParseFoldExpression(Result, T);
+
       ExprType = SimpleExpr;
       Result = Actions.ActOnParenListExpr(OpenLoc, Tok.getLocation(),
                                           ArgExprs);
     }
-  } else if (Tok.is(tok::ellipsis) &&
-             isFoldOperator(NextToken().getKind())) {
-    return ParseFoldExpression(ExprResult(), T);
   } else {
     InMessageExpressionRAIIObject InMessage(*this, false);
-    
+
     Result = ParseExpression(MaybeTypeCast);
     ExprType = SimpleExpr;