re PR c++/55856 (ICE on tuple with rvalue ref member)

	PR c++/55856
	* semantics.c (build_data_member_initialization): Handle DECL_EXPR.

From-SVN: r194865

gcc/cp/ChangeLog

 2013-01-03  Jason Merrill  <jason@redhat.com>
 
+	PR c++/55856
+	* semantics.c (build_data_member_initialization): Handle DECL_EXPR.
+
 	PR c++/53650
 	* call.c (type_has_extended_temps): New.
 	* cp-tree.h: Declare it.

gcc/cp/semantics.c

@@ -5848,15 +5848,19 @@ build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec)
       member = TREE_OPERAND (t, 0);
       init = unshare_expr (TREE_OPERAND (t, 1));
     }
-  else
+  else if (TREE_CODE (t) == CALL_EXPR)
     {
-      gcc_assert (TREE_CODE (t) == CALL_EXPR);
       member = CALL_EXPR_ARG (t, 0);
       /* We don't use build_cplus_new here because it complains about
 	 abstract bases.  Leaving the call unwrapped means that it has the
 	 wrong type, but cxx_eval_constant_expression doesn't care.  */
       init = unshare_expr (t);
     }
+  else if (TREE_CODE (t) == DECL_EXPR)
+    /* Declaring a temporary, don't add it to the CONSTRUCTOR.  */
+    return true;
+  else
+    gcc_unreachable ();
   if (TREE_CODE (member) == INDIRECT_REF)
     member = TREE_OPERAND (member, 0);
   if (TREE_CODE (member) == NOP_EXPR)

gcc/testsuite/g++.dg/cpp0x/constexpr-ctor11.C

+// PR c++/55856
+// { dg-options -std=c++11 }
+
+struct A
+{
+  A(const char *);
+};
+
+template <class T>
+struct B
+{
+  T t;
+  template <class U> constexpr B(U&& u): t(u) { };
+};
+
+B<A&&> b("");