Re: libraries order during linking

[Thomas Weber]

On Sat, Jul 03, 2010 at 05:18:27AM -0700, Sergei Steshenko wrote:
> 
> 
> --- On Sat, 6/26/10, Sergei Steshenko <address@hidden> wrote:
> 
> > From: Sergei Steshenko <address@hidden>
> > Subject: libraries order during linking
> > To: address@hidden
> > Date: Saturday, June 26, 2010, 7:17 PM
> > Hello,
> > 
> > I am still building octave-3.0.5 and I've noticed that
> > libraries are supplied
> > in this order : "-lcblas -lf77blas -latlas".
> > 
> > I think that 'atlas' has some functions names the same way
> > as 'blas' ones.
> > 
> > If this is correct, shouldn't the order be "-latlas -lcblas
> > -lf77blas" for
> > 'atlas' functions to be picked ?
> > 
> > Thanks,
> >   Sergei.
> > 
> > 
> >       
> > 
> 
> Anybody ?

It's my understanding that the order at build time doesn't matter. At
run time, the linker needs to find the symbols and will take the first
match. So, as long as ATLAS comes before the normal BLAS when resolving
the symbols, the ATLAS functions will be taken. 

One can achieve that by ldd.conf or LD_PRELOAD.

In fact, Debian packages are built without ATLAS even being installed.

        Thomas