Re: Any AIX experts out there?

On Sat, Feb 01, 2003 at 11:25:03PM +0100, M.-A. Lemburg wrote:
> Neal Norwitz wrote:
>
> >I am able to build now based on information provided by Gary Hooks
> >from IBM.  Here's what he said:
> >
> >        The python.exp list is wrong.  Using only the #! means that
> >        every listed symbol is a deferred import, and those are
> >        resolved by loading subsequent modules or calling loadbind().
> >        What you need is a first line that has 3 characters: "#!."
> >        The period is critical.  It tells the binder,and later the
> >        loader, that the symbol comes from the main application.  This
> >        is why the module call-back fails.
> >
> >        The "." syntax was introduced in AIX 4.2.  The question is
> >        really, what code was doing the dynamic loading?  If it worked
> >        on AIX 3.2 and 4.1, then it's pretty certain that Jens
> >        Uwe-Mager's dlopen implementation was being used, and his code
> >        did a full loadbind() of every module against every other
> >        module.  That would have resolved the deferred imports.
> >        AFAIK, that old dlopen code still works, although we encourage
> >        people to use the native dlopen API.
> >
> >        If you put the period in, the import list won't be handled
> >        properly pre-4.2.  Yes, much changed in that release.  So you
> >        have a bit of a conundrum.  Not sure if configure can be
> >        trained to figure out the version/release and manipulate the
> >        import list appropriately...
> >
> >I've modified configure to recognize if we are AIX 4.2+ and add in the
> >period.  Is it possible that no one else is using dynamic (shared)
> >libraries on AIX 4.2+?
> 
> No :-)
> 
> I've built Python on AIX a couple of times (both on AIX 3 and 4)
> and always used shared libs (the mx tools and other third party tools).

Did you use AIX 4.2/4.3 or 4.1?

Do you have the dlopen library installed (Jens Uwe-Mager reference above)
or is dynload_aix being used? (see DYNLOADFILE in Makefile)

Do you know if the compiler, etc. were built on 4.2/4.3 or perhaps
on an earlier version?  (Not sure if this would matter or not.)

> I never had to change python.exp, so I'm not sure whether this
> really fixes the problem.

It does allow imports of dynamic libraries to succeed on the test
machine.  Before it would crash.

> Could be that makexp_aix needs fixing though: it relies on the
> format of nm output, so if that changes, it's likely to cause
> problems.

I agree that makexp_aix could need upgrading.  nm isn't a problem
for me now, but I agree with you.

I'm still not comfortable making the change.  I'd really like 
feedback from AIX users.  MAL, can you test if adding a period
works for you?  The easiest way to make the change is modifying
the Makefile (after running configure) and change \"\" to a period
".".

I will definitely update the AIX-NOTES file.

Neal