1  /* Test to verify that a strlen() call with a pointer to a dynamic type
       2     doesn't make assumptions based on the static type of the original
       3     pointer.  See g++.dg/init/strlen.C for the corresponding C++ test.  */
       4  
       5  struct A { int i; char a[1]; void (*p)(); };
       6  struct B { char a[sizeof (struct A) - __builtin_offsetof (struct A, a)]; };
       7  
       8  __attribute__ ((noipa)) void
       9  init (char *d, const char *s)
      10  {
      11    __builtin_strcpy (d, s);
      12  }
      13  
      14  struct B b;
      15  
      16  __attribute__ ((noipa)) void
      17  test_dynamic_type (struct A *p)
      18  {
      19    /* The following call is undefined because it writes past the end
      20       of the p->a subobject, but the corresponding GIMPLE considers
      21       it valid and there's apparently no way to distinguish invalid
      22       cases from ones like it that might be valid.  If/when GIMPLE
      23       changes to make this possible this test can be removed.  */
      24    char *q = (char*)__builtin_memcpy (p->a, &b, sizeof b);
      25  
      26    init (q, "foobar");
      27  
      28    if (6 != __builtin_strlen (q))
      29      __builtin_abort();
      30  }
      31  
      32  int main (void)
      33  {
      34    struct A *p = (struct A*)__builtin_malloc (sizeof *p);
      35    test_dynamic_type (p);
      36    return 0;
      37  }