This topic is rather old, and I'm referring to a particular post which
can be found here:
http://www.mail-archive.com/libtool@gnu.org/msg03642.html
Obviously it isn't possible to link a static lib from a shared lib
compiled in libtool as libtool blocks it (technically it would be
possible on many, but not all platforms). This affects all platforms
including Windows, not just Mac OS X.
Robert Boehne suggested some solutions to this:
> Suggestion 1, you could link to shared libraries rather than archives.
>Suggestion 2, if you're building it yourself, make the static libs
>convenience libraries, this will have the same effect as linking to
static libs, but is portable.
This doesn't cover a special case though which I heard isn't *that*
uncommon and which wasn't mentioned in the discussion at all:
Sometimes you create plugins/modules which refer back to functions in
the main program.
On Unix, you can simply do this by unresolved symbols that get resolved
to the main program itself at the point when it loads the shared libs.
On Windows, where unresolved symbols aren't allowed, I am myself
commonly generating a .a symbol file from the main program's symbols and
linking it statically from my dlls, which works fine with mingw and also
generates perfectly usable dlls.
Now with libtool this isn't possible. In my project, that led me to an
ugly hack where I'm simply not using libtool for my modules at all when
compiling for a windows target.
That's a rather unsatisfying solution. It works, but the condition in
every Makefile.am of every module that contains both libtool code and
manual code just for the windows platform to get it compiled seems
rather ugly compared to a much simplier solution:
It could much easier be solved by libtool providing a switch to override
the blocking of static linking out of shared libs. In my case, that also
wouldn't impose a problem to Unix systems not supporting it, as I'd
simply use it solely for the Windows platform where the .a link is
needed to avoid unresolved symbols.
As the problem seems, after 6 years, still unresolved (if I'm wrong
please correct me, I'm by no way an expert or even an advanced libtool
user), it would be really great if such a flag got introduced: people
may use or not use it depending on the target platforms they want to
support, or they may even use it only through an optional condition for
individual target platforms of which they know that they support static
linking out of shared libs to achieve specific things - in my case
avoidance of unresolved symbols.
This wouldn't cause a loss of compatibility for the average libtool user
and provide a considerable amount of less pain in this specific special
case.
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