ld and linktime/runtime lib dirs

[vda <vda at port dot imtp dot ilyichevsk dot odessa dot ua>]

This is a little conversation originated on gcc list.
Question I'm interested in is at the end, please read on.


From: vda <vda@port.imtp.ilyichevsk.odessa.ua>
To: Andreas Jaeger <aj@suse.de>

> There shouldn't be any shared libs in /lib that you link against.  But
> anything outside /usr/lib has to be specified.

Does that mean that I have to dig into and modify KDE makefiles if some
of required libs are NOT in [/usr]/lib?

I looked there and become worried: it looks like KDE will record paths to my 
QT libs in KDE libs (via -rpath) which I _don't want_ to happen! "Hardcoded 
paths to libs??!! AAAAAARRRRRRGGGGGGHHHHHH!!" :-)

I thought it's admin job to put all lib dirs into /etc/ld.so.conf, it adds
flexibility: I can move them around and KDE won't break.

And it's only a part of a problem: while KDE configure have dirty hooks for 
QT libs in it's own dirs, it doesn't do that for other less famous libs 
(pcre lib).

I tried to set LD_LIBRARY_PATH to `cat /etc/ld.so.conf` for KDE make but it 
still moaning about -lpcre...

Is there a way to tell make what lib dirs to use without encoding them in 
rpath? Makefile is autogenerated, I hope to avoid makefile hacking. Any 
environment vars?

> KDE should find those itself.  configure has a switch for e.g. the qt
> Dir and might also have it for others:
>
> ./configure \
>   --prefix=/opt/kde2 \
>  --with-qt-dir=/usr/lib/qt2/

Yes, that's the (ugly) way KDE makefile adds -L and -rpath to gcc/ld.
It does not do that for pcre lib etc.

I want to say: "Hey make, these are my lib dirs, use them for ld, but 
don't encode them into .so libs you make! I'm deadly sure I'll give them good 
/etc/ld.so.conf at runtime!"

Looks like this isn't trivially possible.


If anyone knows how to do it, please enlighten me.
It is ok to tell me that I'm doing something silly/wrong,
but _don't forget_ to CC me :-) Thanks.
--
vda