Re: [PATCH] Re: Problem on rs6000-ibm-aix4.3.2.0 (Fortran) -DPIC

[Kevin Ryde]

Robert Boehne <address@hidden> writes:
>
> Yet again I am suprised by the diversity of uses for Libtool,
> I hadn't imagined this m4->asm script.  I am curious as to what tag
> it uses, the plain old C (empty) tag?

Yes, the rule for automake looks like

.asm.lo:
        $(LIBTOOL) --mode=compile --tag=CC $(top_srcdir)/mpn/m4-ccas 
--m4="$(M4\)" $(CCASCOMPILE) -c `test -f $< || echo '$(srcdir)/'`$<

--tag must be given explicitly, because of course m4-ccas is not the
same as $CC so libtool can't infer it.

The C compiler is a good way to run the assembler.  We know how to
stick it in the right mode (ABI, cpu submodel, etc), and can just let
it invoke the assembler the right way.

And running libtool as such is an easy way to cooperate with the
choice between static or shared, and the object file going to foo.o or
.libs/foo.o.

> if you only support
> gcc, then your script could grep CFLAGS for -fpic or -fPIC to see if
> you're attempting to generate PIC code.

In theory we support various vendor compilers.  I guess it'd be
possible to look for the $pic_flag which libtool adds.