per-file symbol versioning

[Benjamin Kosnik]

Is there a way to do per-file symbol versioning? Say there exists a new
implementation of libsupc++/demangle.o that has a bunch of std::vector
instantiations that need to be internal-linkage only. Currently, they
are versioned with GLIBCPP_3.2 due to the way the symbol versioning file
(link-map.gnu) is set up.

I could do more edits to the symbol-versioning file, but
am wondering if there is a cleaner solution.

Is there a way to say, hey, for this file only use these rules? Or is
there a way to break apart the libstdc++ and libsupc++ symbol versioning
(which are now done at the same time as libsupc++ is a convenience
library) so that in the libsupc++ symbol-versioning file all the
namespace std:: symbols are not exported, and internal only?

Hmmm...

-benjamin