Fix for PR3418: make sure to handle the RHS of expressions starting with 
__extension__.  This sort of construct shows up in the gcc source code.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63100 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index f701499..5ff0905 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -366,6 +366,7 @@
       // __extension__ can start declarations and it can also be a unary
       // operator for expressions.  Consume multiple __extension__ markers here
       // until we can determine which is which.
+      // FIXME: This loses extension expressions in the AST!
       SourceLocation ExtLoc = ConsumeToken();
       while (Tok.is(tok::kw___extension__))
         ConsumeToken();
@@ -381,21 +382,14 @@
         // FIXME: Pass in the right location for the end of the declstmt.
         R = Actions.ActOnDeclStmt(Res, DeclStart, DeclStart);
       } else {
-        // Otherwise this was a unary __extension__ marker.  Parse the
-        // subexpression and add the __extension__ unary op. 
-        OwningExprResult Res(ParseCastExpression(false));
+        // Otherwise this was a unary __extension__ marker.
+        OwningExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc));
 
         if (Res.isInvalid()) {
           SkipUntil(tok::semi);
           continue;
         }
 
-        // Add the __extension__ node to the AST.
-        Res = Actions.ActOnUnaryOp(CurScope, ExtLoc, tok::kw___extension__,
-                                   move_arg(Res));
-        if (Res.isInvalid())
-          continue;
-
         // Eat the semicolon at the end of stmt and convert the expr into a
         // statement.
         ExpectAndConsume(tok::semi, diag::err_expected_semi_after_expr);