Re: Problems with AIX4 Compiler

[Tim Mooney]

In regard to: Re: Problems with AIX4 Compiler, Erik Lindahl said (at...:

>>The -Wl,-blibpath:$libdir/usr/lib:/lib
>>
>>is a really really good idea, though. You definitely don't want that to
>>go away, or many of the binaries you generate with libtool will have
>>horrible security problems, because the linker is going to stick *some*
>>libpath in the loader section.  If you don't tell it to use a good one
>>(like the one above), it's going to use one based on the `-L' flags it
>>saw.  That opens you up for all kinds of problems.
>>
>
>Tim, while I do agree the security feature is nice this currently breaks
>libtool in a bad way when you try to use the MPI compiler mpcc to
>build parallel programs on aix; although libtool thinks shared libraries
>are supported, they are not. The compile is ok, but you can't run the
>program.

libtool (and many GNU projects) support based on "popularity", meaning
that the "stuff" (features, OSes, etc. -- in this case, compilers and
build environments) that is most widely used gets support first, and support
for new "stuff" comes when someone needs it and helps get it in place.
Since most users on AIX systems are using either gcc or IBM's cc, that's
what's supported the best.  This also means that libtool works for the
vast majority of people on AIX.  It misses the "edge cases", and here's
a good one you've just pointed out.

I believe it should be very do-able to add support for an additional compiler
on AIX.  Since you have access to mpcc, perhaps you would want to consider
helping with this?  You might want to take a look at the stanza for Linux
and C++ or C -- since there are multiple options for C or C++ compiler there,
it might make a good template for how to add support for mpcc on AIX.  Once
you have that in place there, other people will benefit too, since MPI is
also popular on SGI's Origin's, Beowulf clusters, and elsewhere.

If you've got a patch that you think is close (and it's not huge) submit
it to this list for comments and review.  Since I don't have access to an
SP2 or other IBM system with MPI, I can't test, but there might be others
that could, and the peer review might turn up some issues.

Look forward to seeing the patch.  ;-)

Tim
-- 
Tim Mooney                              address@hidden
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