On 05/10/2018 04:05 PM, Marc Glisse wrote: > On Thu, 10 May 2018, Martin Sebor wrote: > >> Can you please comment/respond to Jeff's question below and >> confirm whether my understanding of the restriction (below) >> is correct? > > I don't remember it at all, I really should have expanded that comment... > > The documentation of nonzero_chars seems to indicate that, unless > full_string_p, it is only a lower bound on the length of the string, so > not suitable for this kind of alias check. I don't know if we also have > easy access to some upper bound. > > (I noticed while looking at this pass that it could probably use > POINTER_DIFF_EXPR more) So ISTM that we'd need to guard the code that uses si->nonzero_chars in maybe_invalidate to also check FULL_STRING_P since it appears we're using si->nonzero_chars as a string length.
jeff
