1  /* { dg-do compile } */ 
       2  /* { dg-options "-O2 -fdelete-null-pointer-checks -fisolate-erroneous-paths-attribute -fdump-tree-isolate-paths -fdump-tree-forwprop3" } */
       3  /* { dg-skip-if "" keeps_null_pointer_checks } */
       4  
       5  
       6  int z;
       7  int y;
       8  
       9  int * foo(int a) __attribute__((returns_nonnull));
      10  int * bar(void) __attribute__((returns_nonnull));
      11  
      12  int *
      13  foo(int a)
      14  
      15  {
      16    switch (a)
      17      {
      18        case 0:
      19          return &z;
      20        default:
      21          return (int *)0;
      22      }
      23  }
      24  
      25  
      26  int *
      27  bar (void)
      28  {
      29    return 0;
      30  }
      31  
      32  /* We testing that the path isolation code can take advantage of the
      33     returns non-null attribute to isolate a path where NULL flows into
      34     a return statement.  We test this twice, once where the NULL flows
      35     from a PHI, the second with an explicit return 0 in the IL.
      36  
      37     We also verify that after isolation cprop simplifies the
      38     return statement so that it returns &z directly. */
      39  /* { dg-final { scan-tree-dump-times "__builtin_trap" 2 "isolate-paths"} } */
      40  /* { dg-final { scan-tree-dump-times "return &z;" 1 "forwprop3"} } */
      41  
      42