Re: Tune rpath by env. variable

[Pavel Raiskup]

On Thursday 11 of December 2014 23:29:56 Gary V. Vaughan wrote:
> I applied your patch with some fairly heavy-handed changes:
>
>   1. Added a NEWS update.
>   2. Simplified the new documentation.
>   3. Changed the name of some internal API symbols.
>   4. Fixed dollar quoting with quadrigraphs, and then expand the shared
>      function directly into libtool.

Thanks a lot for all of this ^.

>   5. Remove the scripts for slicing and dicing that function out of one
>      file and into another the hard way.

The libtool's code is so sophisticated, thanks, thats perfect!  I need
to give the code-reading another chance (yeah a minute or so) to review
everything properly;  I'll do so but it looks fine to me now.

> I still have some small concerns about the correctness.
>
> Do we really want the configure time LT_SYS_LIBRARY_PATH adjusted
> lt_lib_dlsearch_path_spec injected into the installed libtool script? That
> makes me think that if LT_SYS_LIBRARY_PATH is set in /etc/profile or similar,
> that the adjustment will happen twice.

Yes.  Thats why I wanted let the libtool ignore environment var (to avoid
duplicities);  and because for me, the ./configure time
LT_SYS_LIBRARY_PATH seems to be more important...

> I think it would work better to leave lt_lib_dlsearch_path_spec in the
> generated file as it was before (just the heuristic configure time values),
> and add to the top of libtool:
>
>   : ${LT_SYS_LIBRARY_PATH="/configure/time:/path/list"}
>
> Then installed libtool will work whether the user wants to set it differently,
> or not at all, or if LT_SYS_LIBRARY_PATH is set in the environment for both
> configure and libtool, without double adjusting.
>
> WDYT?

Thats definitely cleaner.  Ack.  I mean, only if we still can use
LT_SYS_LIBRARY_PATH to enhance ltdl.m4's runtime library path
during ./configure time.  Now however, the path munging routine from
libtool.m4 should be easy to reuse in ltdl.m4.  And also if:

  LT_SYS_LIBRARY_PATH="/lib64:/usr/lib64:" ./configure

.. is enough to to stop thinking about LT_SYS_LIBRARY_PATH during
development as it should survive things like 'touch configure.ac ; make'.

Pavel