On Fri, Apr 20, 2012 at 4:40 PM, Ian Lance Taylor <i...@google.com> wrote: > "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.
In our usage, the backup definition may not be at the end of command line since it may reference library symbols. -- H.J.
