| /* { dg-do run } */ |
| |
| struct list { struct list *n; }; |
| |
| struct obj { |
| int n; |
| struct list l; |
| } _o; |
| |
| struct list _l = { .n = &_o.l }; |
| |
| int main(int argc, char *argv[]) |
| { |
| struct obj *o = &_o; |
| _o.l.n = &_l; |
| while (&o->l != &_l) |
| /* Note the following is invoking undefined behavior but in |
| this kind of "obvious" cases we don't want to break things |
| unnecessarily and thus we avoid analyzing o as pointing |
| to nothing via the undefined pointer subtraction. Instead |
| we canonicalize the pointer subtraction followed by the |
| pointer conversion to pointer offsetting. */ |
| o = ((struct obj *)((const char *)(o->l.n) |
| - (const char *)&((struct obj *)0)->l)); |
| return 0; |
| } |
