On 06/20/2017 03:27 AM, Jakub Jelinek wrote:
Hi!
bootstrap-ubsan revealed many
../../gcc/ira-costs.c:1747:20: runtime error: member access within null pointer
of type 'cost_classes *[107]'
issues. The problem is that cost_classes_ptr is sometimes NULL, but
in those cases we have early exit:
if (! allocno_p)
{
if (regno_reg_rtx[i] == NULL_RTX)
continue; // <----- HERE
memcpy (temp_costs, COSTS (costs, i), struct_costs_size);
i_mem_cost = temp_costs->mem_cost;
}
else
{
if (ira_regno_allocno_map[i] == NULL)
continue; // <----- or HERE
...
}
Still, cost_classes_ptr->classes where classes is an array is UB when
cost_classes_ptr is NULL, so this patch moves it after the if (...) continue;
in both branches (because it is needed both later in the else ...
and after the whole if.
Bootstrapped/regtested on x86_64-linux and i686-linux (with
bootstrap-ubsan), ok for trunk?
Sure.
Jakub, thank you for addressing the issue.
2017-06-20 Jakub Jelinek <[email protected]>
* ira-costs.c (find_costs_and_classes): Initialize cost_classes later
to make sure not to dereference a NULL cost_classes_ptr pointer.
