gcc/testsuite/gcc.dg/Wstrict-overflow-18.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-fstrict-overflow -O2 -Wstrict-overflow" } */
   3
   4 /* Don't warn about an overflow when folding i > 0.  The loop analysis
   5    should determine that i does not wrap.
   6
   7    The test is really bogus, p->a - p->b can be larger than INT_MAX
   8    and thus i can very well wrap.  */
   9
  10 struct c { unsigned int a; unsigned int b; };
  11 extern void bar (struct c *);
  12 int
  13 foo (struct c *p)
  14 {
  15   int i;
  16   int sum = 0;
  17
  18   for (i = 0; i < p->a - p->b; ++i)
  19     {
  20       if (i > 0)  /* { dg-bogus "warning" "" { xfail *-*-* } } */
  21         sum += 2;
  22       bar (p);
  23     }
  24   return sum;
  25 }