[Bug c++/103629] Possible miscompilation triggered by -fvisibility=hidden

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103629

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Mathieu Malaterre from comment #5)
> (In reply to Andrew Pinski from comment #4)
> > (In reply to Mathieu Malaterre from comment #3)
> > > $ export CXXFLAGS=-fvisibility=hidden
> > 
> > Yes you can't just use -fvisibility=hidden without the source being ready
> > for it.
> 
> Andrew, could you please be a bit more specific. I do not see any changes
> related to duplicate `typeinfo` or `visibility=hidden` in the changelog:
> 
> * https://gcc.gnu.org/gcc-11/changes.html

right there has been no major changes in this area as far as I Know. 

> 
> `-fvisibility=hidden` was added in 2015 in the Debian/OpenVDB package and
> has worked quite well for all users so far. It would be nice if gcc/ld would
> help track any `type_info` issue, in large portable c++ codebase.

It was working by accident before. Do you know why it was added? Has the code
upstream in OpenVDB been fixed for adding the visibility attribute where
needed?