--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/cpp/if-unary.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,32 @@
+/* Copyright (C) 2000 Free Software Foundation, Inc.  */
+
+/* { dg-do preprocess } */
+
+/* Test the various unary operators.  */
+
+#if 1 + + + 1   /* allow multiple unary sign operators :) */
+#endif
+
+#if 8 - +3 != +4 + +1
+#error		/* { dg-bogus "error" "unary +" } */
+#endif
+
+#if -2 - -1 != -1
+#error		/* { dg-bogus "error" "unary -" } */
+#endif
+
+#if ~0 != -1
+#error		/* { dg-bogus "error" "unary ~" } */
+#endif
+
+#if !0 && (!1 == 0) && !!1 != 1
+#error		/* { dg-bogus "error" "unary !" } */
+#endif
+
+#if ~~8 != 8
+#error		/* { dg-bogus "error" "double unary ~" } */
+#endif
+
+#if 5 + +!-4 != 5
+#error		/* { dg-bogus "error" "compound unary +, !, -" } */
+#endif