Allow using a system-installed giflib

[Andrew Hughes]

----- Original Message -----
> Hi,
> 
> Updated webrev at:
> http://cr.openjdk.java.net/~omajid/webrevs/system-giflib/01/
> 
> The webrev borrows some idioms that Andrew Hughes pointed out, and
> uses
> system headers for giflib too.
> 
> I checked this by building --with-libgif=system and also by removing
> the
> src/share/native/sun/awt/giflib dir and using --with-giflib=system.
> 

This looks better, though I'd still like to see it using a more
standard --enable format.  That then removes the need to have that
third error case. I'll post a webrev to fix both this and zlib once
committed.

> On 03/08/2013 12:26 PM, Phil Race wrote:
> > If I understand correctly, this removes the directory containing
> > the JDK's copy of giflib sources from the set of locations to be
> > compiled etc, and replaces it with just a link line pointer to use
> > "libgif" which is then expected to be on the default linker path,
> > ie in /usr/lib.
> > 
> > I think this is fine except I would guard USE_EXTERNAL_LIBGIF
> > with an expectation that this is at least "not" windows, since
> > I'm pretty sure that option would always be a mistake there.
> 
> The updated webrev does that. I don't have a windows machine to test
> this on, unfortunately.
> 

This does cause some duplication.  Is this really a major issue?  It's
not the default and, if I was someone on Windows trying to get system
giflib working, this would just get in the way.  We had to remove something
similar in the zlib case that blocked it if not on Mac OS X.

> Any comments or suggestions?
> 
> Thanks,
> Omair
> 
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-- 
Andrew :)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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