Re: RFC: linker enhancements

[Alan Modra <amodra at bigpond dot net dot au>]

On Wed, Mar 17, 2004 at 10:26:16AM -0800, H. J. Lu wrote:
> On Wed, Mar 17, 2004 at 10:41:49PM +1030, Alan Modra wrote:
> > On Wed, Mar 17, 2004 at 07:31:16AM +0100, Jakub Jelinek wrote:
> > > > One side-effect of this patch is that when --only-if-needed is in
> > > > effect, weak definitions in normal files won't be overridden by
> > > > a strong definition in a shared library.  I'm not sure whether that's
> > > > a bug or a feature..
> > > 
> > > Only if the library is not included, or when it is actually needed as well?
> > 
> > Potentially both cases.  elf_link_add_object_symbols won't use a strong
> > definition in the lib in preference to a weak definition in a regular
> > file until some other definition is needed from the library.  At that
> > point, further weak definitions in regular objects will be overridden.
> 
> Do you have a testcase for that? I think the current linker will never
> let any definition from a shared libray override a weak definition in
> a regular file.

Search for dt_needed in elflink.c and elflink.h.  You'll soon see what
I'm talking about.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre