Re: [libunwind] semantics of ALIAS?

[David Mosberger]

>>>>> On Thu, 25 Mar 2004 13:33:30 -0600 (CST), Todd L Miller <address@hidden> 
>>>>> said:

  Todd> That is, I need specify that the entry state is the same as
  Todd> the state at a particular IP, and _not_ that the rest of the
  Todd> procedure follows the aliased procedure in lock-step.  How can
  Todd> I construct such a thing?

I think we may be able to refine the current implementation of
UNW_DYN_ALIAS.  In parse_dynamic(), try changing:

              new_ip = op->val + ((sr->when_target / 3) * 16
                                  + (sr->when_target % 3));

into something along the lines of:

              when = MIN (sr->when_target, sr->region_len);
              new_ip = op->val + (when / 3) * 16 + (when % 3);

Since you'll be putting the ALIAS directive into an empty region, this
should bound it to a single point in the original code.

        --david