gcc/testsuite/gcc.dg/pr8715.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-Wsign-compare -std=c99" } */
   3
   4 #include <stdbool.h>
   5
   6 int foo()
   7 {
   8   unsigned char b = '1';
   9
  10   bool x = ~b; /* { dg-warning "promoted ~unsigned is always non-zero" } */
  11
  12   return 0;
  13 }