re PR c++/56481 (endless loop compiling a C++ file)

	PR c++/56481
	* g++.dg/cpp0x/constexpr-and.C: New.

From-SVN: r196359

gcc/testsuite/ChangeLog

+2013-02-28  Jason Merrill  <jason@redhat.com>
+
+	PR c++/56481
+	* g++.dg/cpp0x/constexpr-and.C: New.
+
 2013-02-28  Martin Jambor  <mjambor@suse.cz>
 
 	PR tree-optimization/56294

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

+// PR c++/56481
+// Non-linearity in potential_constant_expression_1
+// { dg-options -std=c++11 }
+
+struct S
+{
+  constexpr bool foo ();
+#define A(n) , f##n##0, f##n##1, f##n##2, f##n##3
+#define B(n) A(n##0) A(n##1) A(n##2) A(n##3)
+#define C B(0) B(1) B(2) B(3)
+  bool f C;
+};
+
+constexpr bool
+S::foo ()
+{
+#undef A
+#define A(n) && f##n##0 && f##n##1 && f##n##2 && f##n##3
+  return f C;
+}