Re: FYI: duplicate removal patch [Was Re: ok, new libtool for cygwin updates]

[Gary V . Vaughan]

Hello.

On Sunday 01 April 2001  3:59 pm, Michael Matz wrote:
> On Sun, 1 Apr 2001, Gary V. Vaughan wrote:
> > > I see.  Argh, This then again means, that libtool will probably
> > > generate excessively large link commands for KDE.
> >
> > Yes it does =(O|  Although ugly, Robert has applied the following to MLB
> > so that portability at least is not affected in that case:
>
> I know about the incremental linking (but I'm not sure it also applies to
> libraries, or only to .o files. Given how it works (using ld -r IIRC) it
> normally only _can_ work with .o's, because _all_ libs have to be
> mentioned in one link command, to have any effect).

That's true... I was thinking about problems that might arise due to 
massively increased command line lengths.  I suppose we have a new problem 
now though:  What to do where a link command has so many libraries listed, 
that the command line length limit is reached on certain hosts?  Ugh.

Perhaps we do need to reinstate duplicate removal on a per-platform basis, 
and just hope that we don't find a host with severe command line length 
limits *and* an inability to cope with unordered dependent library lists.  
Experience shows that platforms that have brain-damage tend to have it in 
many places or else not at all (or hardly at all), so I expect hoping 
otherwise is naive.  Our only hope is that the original bug remained 
undetected  for so long because no one is trying to use libtool on such a 
platform right now =(O|

> > > Furthermore it really makes no sense to _not_ remove
> > > duplicates for shared libs (it only applies to archives), because
> > > anyway only the first one is searched for undefined symbols.
> >
> > Certainly for modern UNIX architectures, however, I get the impression
> > from Alexandre that there are platforms which do require topologically
> > ordered listings of shared libraries in the final link line in order to
> > be able to
>
> Hmm, Alexandre?  Are there really platforms where this is the case for
> shared libs?

It seems that even if there are, there is little option but to do 
platformwise duplicate removal if we are to avoid common problems with 
command line lengths.  I'll post a patch in the next day or two.

Cheers,
        Gary.
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