[Bug libstdc++/54482] failures in static linking with libstdc++, due to versioned symbols

[aaw at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54482

--- Comment #3 from Ollie Wild <aaw at gcc dot gnu.org> 2012-09-12 04:58:29 UTC ---
Note, however, that simply changing pic_flag to

  pic_flag="-D_GLIBCXX_SHARED  -fPIC -DPIC"

is insufficient.  It suffers from the same issue as the original problem,
namely that, when configured with --with-pic, pic_flag is passed even when
compiling objects for libstdc++.a.  Since your solution passes -DPIC and
-D_GLIBCXX_SHARED in tandem, keying off the new macro suffers from the same
limitations as the old one.

See my previous comment.  In particular, the link there points to a more
detailed analysis, as well as a patch which outlines the basics of what I think
needs to change.  As you correctly suggest, we need a mechanism to pass flags
based on whether we're compiling for a static or shared library independently
of whether or not -fPIC is used.  The aforementioned patch does that in our
branch, but that will need to be cleaned up and submitted to upstream libtool
before incorporating it in GCC trunk.