support additional architectures with autoconf

[bernstei]

It would be nice if FoX's autoconf stuff was updated to support newer architectures, e.g. aarch64 and ppc64le. I don't really know much about autoconf, but would hope that it's as simple as updating autoconf itself, rerunning whatever generates files like config.sub, and pushing those back in. Is there anyone who already knows how to do this?

[bernstei]

I guess maybe #4 is the reason this hasn't been done before :(

[bernstei]

I have a tentative patch that makes FoX compatible with modern autoconf 2.69, at the expense of going back to relying entirely on the autoconf-distributed lang.m4 and fortran.m4, and therefore probably losing compatibility with some old compilers, e.g. ones that cannot do their own source preprocessing.

@andreww is that of interest, or would you rather not break that level of backward compatibility, or have another reason to avoid it?

[andreww]

Yes - #4 (and my lack of time and fading ability with m4) has been the barrier to this kind of thing.

I think the exchange of the loss of some backward compatibility for a more updatable build system is fair. So yes @bernstei, a patch to update to a modern autoconf would be awesome. I need to merge a bunch of other patches and push out a new version, but I don't think this interacts with with any of that.

[andreww]

Can this be closed now or is additional work/testing needed?

[bernstei]

On Feb 23, 2021, at 12:10 PM, Andrew Walker ***@***.******@***.***>> wrote: Can this be closed now or is additional work/testing needed?

If you don't mind waiting until the downstream things to update and see if that problem really is fixed, I hope it won't take long, and I'll follow up here once we know.

[bernstei]

Looks like we may also need newer versions of config.sub and/or config.guess. Should I start a new PR for that?

[andreww]

Yes please. I wonder if it's just a case of using new ones from the autoconf source or if it will need more thought?

[andreww]

I think this is now fixed on master.

[bernstei]

On Mar 4, 2021, at 6:29 AM, Andrew Walker <notifications@github.com<mailto:notifications@github.com>> wrote: I think this is now fixed on master. Thanks. I've propagated the changes, and we should have CI results on various architectures in a few days. Noam