gcc/testsuite/gcc.dg/tree-ssa/isolate-2.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fisolate-erroneous-paths-attribute -fdump-tree-isolate-paths -fdump-tree-phicprop1" } */
   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 phi-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 "phicprop1"} } */
  41 /* { dg-final { cleanup-tree-dump "isolate-paths" } } */
  42 /* { dg-final { cleanup-tree-dump "phicprop1" } } */
  43
  44