[Bug libstdc++/85298] New: relocation errors on windows when linking C code to libstdc++ built with weakrefs

["rkitover at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85298

            Bug ID: 85298
           Summary: relocation errors on windows when linking C code to
                    libstdc++ built with weakrefs
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rkitover at gmail dot com
  Target Milestone: ---

Apologies in case this is a known issue, I was encouraged to report this to gcc
proper.

See discussion here:

https://github.com/Alexpux/MINGW-packages/issues/1580

The issue happens when linking C code such as ffmpeg to other libs that use
libstdc++, then you get a bunch of "relocation truncated to fit" error
messages.

Disabling weakrefs in libstdc++ fixes the issue, as is done in this patch:

https://github.com/Alexpux/MINGW-packages/blob/master/mingw-w64-gcc/0016-disable-weak-refs-in-libstdc%2B%2B.patch

The issue still affects gcc 7.3.0 and starts with gcc 6.0 .