[Bug testsuite/110763] New: FAIL: gcc.dg/ubsan/object-size-dyn.c -O2 execution test

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110763

            Bug ID: 110763
           Summary: FAIL: gcc.dg/ubsan/object-size-dyn.c   -O2  execution
                    test
           Product: gcc
           Version: 13.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: testsuite
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

I see this testcase FAILing because it ends up returning uninitialized memory.
This can be seen when enabling glibc malloc perturbing.  The 'off' method
ands with zero to avoid this.

int
__attribute__ ((noinline))
dyn (int size, int i)
{
  __builtin_printf ("dyn\n");
  fflush (stdout);
  int *alloc = __builtin_calloc (size, sizeof (int));
  int ret = alloc[i];
  __builtin_free (alloc);
  return ret;
}

...

int
main (void)
{
  int ret = dyn (2, 2);

  ret |= off (4, 4, 0);

  return ret;