Re: using getconf in autoconf macro to find 64 bit compile options?

[Ed Hartnett]

address@hidden (Bob Proulx) writes:

> Jeff Sheinberg wrote:
> > Ed Hartnett writes:
> >  > I wonder if there is any autoconf macro for running getconf to find
> >  > the compile flags needed for 64-bit compilation on platforms that
> >  > support it. For example, both the AIX and solaris platforms have
> >  > special compile options to get 64 bit pointers. 
> > 
> > Here is what I am using in my configure.ac,
> > 
> >     # Checks for library functions.
> >     AC_FUNC_FSEEKO
> >     AC_SYS_LARGEFILE
> >     # /\ Prior 2 enables large file support.
> 
> Hmm...  I know that Ed's next message asks about large file support
> and so I don't know and it is easy to get them confused but this
> message is asking about compiling with 64-bit pointers.  The above
> enables large file support but not 64-bit pointers.  Of course in
> 64-bit compilation mode you get large files too.
> 
> I think for 64-bit compilation on platforms that support both that it
> is really better to let the user choose.  Most platforms that support
> multiple architectures really do so without a good policy or plan
> about where libraries go and such.  The user can quite easily choose
> 64-bit at configure time when it is desired.
> 
> Bob

Firstly, thanks for all the informative responses. This is really
helping clear up some confusion here!

I'm all in favor of allowing the use to choose, but the fact is, it's
so confusing that it generates tons of support questions for us, and
as an academic-type institution, my outfit doesn't have dedicated
support people - so all these questions end up in my mailbox!

Thus my attempt to try and make some good default choices for the
user.

I'm thinking perhaps I should have a option at configure enable-64bit
which will turn on 64-bit pointers on whatever architectures I can
figure out. So far I've got a good handle on solaris and AIX, but
that's just the tip of the iceberg!

If anyone else out there is working on this, or has worked out the
flags needed for any platforms, please email or post them.

When I'm done I'll certainly contribute the resulting macros to one or
both of the autoconf macro collection sites.

Thanks again for all the help!

Ed Hartnett
Unidata