[Bug c++/60955] Erroneous warning about taking address of register with std=c++1y

[manu at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60955

--- Comment #4 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
Perhaps also this special case could also be removed by using TREE_NO_WARNING.

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index c91612c..d8374d9 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -6291,7 +6291,10 @@ maybe_warn_about_useless_cast (tree type, tree expr,
tsubst_flags_t complain)
   if (warn_useless_cast
       && complain & tf_warning)
     {
-      if (REFERENCE_REF_P (expr))
+      /* In C++14 mode, this interacts badly with force_paren_expr.  And it
+     isn't necessary in any mode, because the code below handles
+     glvalues properly.  For 4.9, just skip it in C++14 mode.  */
+      if (cxx_dialect < cxx1y && REFERENCE_REF_P (expr))
     expr = TREE_OPERAND (expr, 0);