On Mar 20 21:45, Corinna Vinschen wrote:
> On Mar 20 19:19, Achim Gratz wrote:
> > What's going wrong is that the symbols are also defined in libc.a on
> > 32bit and only in libm.a on 64bit.  The configury for Cygwin removes
> > both -lc and -lm from the list of libraries that should explicitly be
> > linked with, a comment is present that both libc and libm symlink to
> > libcygwin and are implied by gcc anyway.  However that doesn't seem to
> > be the case anymore on both architectures (these files are not symlinked
> > and not hardlinked either), but the symbol construction is just
> > different enough for this not to work on 64bit it would seem.
> 
> No, that's not quite it.  The problem is that on 32 bit the
> *underscored* functions are exported by libc.a.  This is an accident,
> and probably one which is many years old.  Here's what's exported by
> libm.a:
> 
>   nm libm.a | grep copysign
> 	   U __imp__copysign
>   00000000 T _copysign
> 	   U __imp__copysignf
>   00000000 T _copysignf
> 
> And here's what's exported on 32 bit by libc.a.  Note the extra leading
> underscore:
> 
>   $ nm libc.a | grep copysign
>   00000000 T __copysign
> 	   U __imp___copysign
>   00000000 T __copysignf
> 	   U __imp___copysignf
> 
> These underscored versions were always exported additionally by the 32
> bit version but they have never been exported on 64 bit since exporting
> them was wrong from the start.

I'd like to get rid of them but the 32 bit versions has to stick to
them for backward compat.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat