Re: RPATH on x86_64?

[Pierre Ossman]

Ralf Wildenhues wrote:
> * Pierre Ossman wrote on Wed, Mar 01, 2006 at 10:00:43AM CET:
> > Is there perhaps also some environment variable that can be used to pass 
> > this information? That would allow "make RPATHENV=/usr/lib64" and I 
> > wouldn't have to mess with the build system.
>
> Not at the moment.  You could change the setting of
>   sys_lib_dlsearch_path_spec
> in the generated libtool script (once for each tag).
>
> An patch implementing a functionality like the one you desire would be
> useful.  I'm just not sure about exact semantics and syntax:
>
> - a `libtool --mode=link' option, or
> - an environment variable, or
> - a configure option

configure option is probably the safest. That way we avoid exotic 
breakage if some other part relies on the stability of the library path 
list.

OTOH, that would not allow having different settings for different parts 
of the build. In that case an argument upon invocation would be better.

Environment variables should be a complement, not the primary way of 
controlling it.

> Note there's also been the suggestion to allow a specific environment
> variable to contain all kinds of libtool options; or one for each mode.

It would fit in with the CFLAGS/LDFLAGS/etc. that are used for other 
build tools.

> Next question: should it be possible to
> - add paths to this list, or
> - remove paths, or
> - just set the path list to something new?

Add would be the most desirable version. Do we have any use cases for 
the other two?

> Should the paths be normalized or not?

I'm not familiar with the problems of normalised vs not normalised, but 
my gut instinct is to use whatever the user provides. If they for some 
reason need relative paths then let them add that.

> Which setting should override
> which?

Strictly in the order specified would be the most familiar way of doing 
things.

Rgds
--
Pierre Ossman                Telephone: +46-13-21 46 00
Cendio AB                    Web: http://www.cendio.com