gcc/testsuite/gcc.dg/tree-ssa/pta-escape-1.c

   1 /* { dg-do run } */
   2 /* { dg-options "-O -fdump-tree-alias-details -fdelete-null-pointer-checks" } */
   3
   4 int *i;
   5 void __attribute__((noinline))
   6 foo (void)
   7 {
   8   *i = 1;
   9 }
  10 int __attribute__((noinline))
  11 bar(int local_p)
  12 {
  13   int x = 0;
  14   int *j;
  15   int **p;
  16   if (local_p)
  17     p = &j;
  18   else
  19     p = &i;
  20   *p = &x;  /* This makes x escape.  */
  21   foo ();
  22   return x;
  23 }
  24 extern void abort (void);
  25 int main()
  26 {
  27   int k = 2;
  28   i = &k;
  29   if (bar (1) != 0 || k != 1)
  30     abort ();
  31   if (bar (0) != 1)
  32     abort ();
  33   return 0;
  34 }
  35
  36 /* { dg-final { scan-tree-dump "ESCAPED = { NULL ESCAPED NONLOCAL x }" "alias" { target { ! keeps_null_pointer_checks } } } } */
  37 /* { dg-final { scan-tree-dump "ESCAPED = { ESCAPED NONLOCAL x }" "alias" { target { keeps_null_pointer_checks } } } } */