[Bug c++/70909] Libiberty Demangler segfaults (4)

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70909

--- Comment #41 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
(In reply to Mark Wielaard from comment #40)
> Created attachment 40316 [details]
> infinite d_print_comp printing protection
> 
> (In reply to Markus Trippelsdorf from comment #39)
> > Mark, could you please post your path to gcc-patches?
> > Then there might be a chance to get it into binutils before 2.28 gets
> > released.
> 
> I did rewrite the patch a little to remove the const arguments, add just the
> testcases it fixes and allow up to 2 levels of recursion. That is attached.
> 
> But I still haven't figured out why we need to allow 2 levels of recursion
> for some of the cases. See the XXX in the patch. I don't feel I can propose
> this unless we figure out why the level needs to be 2 (and not 3 or...)
> 
> If we figure that out we should add the explanation to the comment. Then we
> can propose it on gcc-patches.

Well, then just use one level of recursion in the patch. And increase the level 
in a possible follow-up patch later on. This will fix most stack overflows. 
If we fail to demangle some weird symbols at first, so be it.