"H.J. Lu" <hjl.to...@gmail.com> writes: > On Fri, Apr 20, 2012 at 3:59 PM, Ian Lance Taylor <i...@google.com> wrote: >> "H.J. Lu" <hjl.to...@gmail.com> writes: >> >>> On Fri, Apr 20, 2012 at 3:10 PM, Cary Coutant <ccout...@google.com> wrote: >>>>> We only have very few bits to in STB_XXX field. >>>> >>>> This is exactly why I'm not in favor of this extension. The feature >>>> doesn't seem compelling enough to use up one of these precious >>>> reserved values (in fact, you're using the next-to-last one that's >>>> reserved for OS use). >>>> >>>> You want a backup definition? Put a weak def at the end of the link line. >>>> >>> >>> It doesn't work for us since the backup definition is >>> always used even if there is a normal definition in >>> a shared library or an archive. >> >> Can you expand on that? How can you refer to the backup definition if >> there is a normal definition? >> > > We need a definition for symbol, foo. Since we don't know if there > is a definition of foo at the final link time. We provide the backup > definition for foo. The backup one is ignored if there is a normal one in > an archive or DSO at link time.
That use case would be satisfied by Cary's suggestion of adding a weak definition of the symbol in an object included at the end of the link line. Ian
