[FFmpeg-devel] Problem building shared libraries using svn-r11100+ on x86_64

Rich Felker dalias
Wed Dec 5 09:25:03 CET 2007

On Tue, Dec 04, 2007 at 11:23:04PM +0100, Nicolas George wrote:
> Le quartidi 14 frimaire, an CCXVI, M?ns Rullg?rd a ?crit?:
> > No need, I've already fixed configure.
> I have seen, but I am not really happy with the concept of changing the
> linking style of the whole library just to change the linking of a few
> global constants.

It's changing the linking style to be more correct and more optimal
for all global constants. This is a good thing. Actually -Bsymbolic
would be the default and only linking mode in any sane shared library

> In particular, I fear this may break some third party applications that
> relied on overloading specific functions of the library.

Overloading specific functions of a library is NOT VALID. Programs
which do so are nonconforming C and have undefined behavior. It was a
huge and nasty mistake of ELF to try to emulate the traditional
possibility of this rather than just forbidding it alltogether.

> The visibility attributes does _exactly_ the same thing than -Bsymbolic, but
> _just_ for the variables where it is needed. Furthermore, it does not
> require a configure test.

It requires a much worse configure test, one for gcc, and moreover for
versions of gcc which specifically support it.


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