libtool, -fPIC and .so libraries

[Michel LESPINASSE]

From: Michel LESPINASSE <address@hidden>
Date: Mon, 13 Nov 2000 04:14:50 -0800
To: David MacKenzie <address@hidden>
Subject: libtool, -fPIC and .so libraries

Hi,

I have a few questions about libtool. I'm sorry to bother you with it -
I have been trying to find answers elsewhere, but without any success.

For one project I've been working on (a linux DVD player), we want to
use libtool to create some plugins. We've been having some trouble
getting it to do what we want though, so I'd like to ask you what is
the right way to do it. The problems we've had are :

* libtool does not want to build an x11 output plugin, it builds a .a
file instead of a .so ... The reason is that some x11 libraries like
libXxf86dga are only distributed as .a files, so libtool does not want
to duplicate the code in there and build a .so plugin from it.
gcc -shared knows how to do it, but libtool does not.

* libtool's insistance on using -fPIC for shared objects is sometimes
annoying. For the mpeg decoder on x86, -fPIC is about a 10% speed
hit... we do not expect to have many simultaneous mpeg decoders
running, so we would rather build the plugin without -fPIC, which is
totally legal. But libtool seems to be built over the assumption that
noone wants to build .so files without -fPIC...

This is all with libtool 1.3.3

Do you know about ways to work around these problems ?

Thanks,

-- 
Michel "Walken" LESPINASSE - Development Engineer at Wind River Systems
Of course I think I'm right. If I thought I was wrong, I'd change my mind.