--- utils.h.orig	2018-09-19 23:05:31 UTC
+++ utils.h
@@ -121,7 +121,7 @@ int clock_gettime(int type, struct timespec *tv);
  * This returns a constant expression while determining if an argument is
  * a constant expression, most importantly without evaluating the argument.
  */
-#define __is_constant(x)						\
+#define __is_it_constant(x)						\
 	(sizeof(int) == sizeof(*(1 ? ((void*)((long)(x) * 0l)) : (int*)1)))
 
 #define __eval_once(func, x)						\
@@ -136,7 +136,7 @@ int clock_gettime(int type, struct timespec *tv);
 #define __eval_safe(func, x) __eval_once(func, x)
 #else
 #define __eval_safe(func, x)						\
-	__builtin_choose_expr(__is_constant(x),				\
+	__builtin_choose_expr(__is_it_constant(x),			\
 			      func(x), __eval_once(func, x))
 #endif
 
