PR c++/66639 - declare __func__ , __FUNCTION__ & __PRETTY_FUNCTION__ constexpr

PR c++/66639 - declare __func__ , __FUNCTION__ & __PRETTY_FUNCTION__ constexpr
* g++.dg/cpp1y/func_constexpr.C: New test.

From-SVN: r235458

gcc/testsuite/ChangeLog

+2016-04-26  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/66639
+	* g++.dg/cpp1y/func_constexpr.C: New test.
+
 2016-04-26  Patrick Palka  <ppalka@gcc.gnu.org>
 
 	PR c++/70241

gcc/testsuite/g++.dg/cpp1y/func_constexpr.C

+// PR c++/66639 - declare __func__ , __FUNCTION__ & __PRETTY_FUNCTION__
+// as constexpr
+// { dg-do compile { target c++11 } }
+
+#define Assert(expr)   static_assert ((expr), #expr)
+#define Compare(a, b)  Assert (0 == __builtin_strcmp (a, b))
+
+constexpr const char* func ()
+{
+  return __func__;
+}
+
+constexpr const char* function ()
+{
+  return __FUNCTION__;
+}
+
+constexpr const char* pretty_function ()
+{
+  return __PRETTY_FUNCTION__;
+}
+
+constexpr const char* f0 = func ();
+constexpr const char* f1 = function ();
+constexpr const char* f2 = pretty_function ();
+
+Compare (f0, "func");
+Compare (f1, "function");
+Compare (f2, "constexpr const char* pretty_function()");