Re: Dynamic Linkage Problem

[Ralf Wildenhues]

Hi Benjamin, Tommi,

* Benjamin Grauer wrote on Tue, Feb 21, 2006 at 04:42:07PM CET:
> 
> i have a problem using automake with Dynamic Library loading (runtime)

This is really a Libtool issue.

> src/program
> 
> src/entities/libModule.la
> 
> now when i want to link at runtime against src/entities/libModule.la,
> lt_dlopen reports that the file was not found
> what i have to do is supply an absolute path to the lib at runtime....

With
  ../libtool --mode=execute -dlopen src/entities/libModule.la \
             src/program

> since the Programm should be portable, i do not know how to do this in
> a general way.
> e.g:
> 
> when developing, the first (library) search path should be ./src/entities/
> when installed, the first search path should be @libdir@/

Right.  You can add
  -R$libdir
to the link flags for the program, so that it finds the installed
modules.  This currently has a drawback, though: on those systems where
the hardcoded run path overrides the shlibpath environment variable
($shlibpath_overrides_runpath=no), above mode=execute line won't get you
the correct uninstalled libraries.

I plan to add sometime an option to specify a run path that should only
be used for the uninstalled executable.

This post (and thread) has a bit more information:
http://article.gmane.org/gmane.comp.gnu.libtool.general/7248

* Tommi Mäkitalo wrote on Wed, Feb 22, 2006 at 08:13:19AM CET:
> 
> I do it in my project Tntntet (www.tntnet.org). The problem is, that automake 
> does not put your @libdir@ in the search-path. I help myself by setting 
> LD_LIBRARY_PATH when developping my programs. The libraries get installed 
> into /usr/local/lib or /usr/lib, which are searched automatically, so this is 
> not a problem after installation.

Note though that on some systems, the variable in question is not
LD_LIBRARY_PATH.

Cheers,
Ralf