[Bug libstdc++/54314] [4.8 Regression] undefined references to 'construction vtable for std::ostream-in-std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> >'

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54314

--- Comment #23 from Jan Hubicka <hubicka at ucw dot cz> 2013-01-26 18:32:15 UTC ---
> I must say I'm surprised by the gimple-fold.c test, I'd really expect
> additional && DECL_VISIBILITY (decl) != VISIBILITY_DEFAULT .
> Another alternative to make those always hidden (which could be an exported ABI
> change for some shared libraries, though unlikely to be actually a real
> problem) would be to add some new bit, either in the tree itself, or better in
> symtab
> node, which would tell gimple-fold.c not to optimize it.  Honza?

Yep, I was just wondering about the same.  It seems C++ frontend has to mark
those
declarations as unusable for referencing.  Is it easy to do on C++ side?
I think we want tree visibility flag here, because we do not really represent
stuff that may get into the game with TBAA.