Making *-netbsd-* to mean ELF not a.out for all CPUs

Making *-netbsd-* to mean ELF not a.out for all CPUs

[John Ericson]

Hello Binutils and GCC lists[1],

I would like to propose that GNU tools consistently interpret configs with "netbsd" as meaning ELF as opposed to a.out. Currently, newer CPUs do that, but older ones have "netbsd" mean a.out for historical reasons, and "netbsdelf" is used instead. This inconsistency is a bit of a nuisance to my distro / package set[2] which aims to support cross compilation to/from arbitrary platforms without special cases. Other platforms that formerly used a.out (like Linux) have long since changed the default to be ELF, so I don't know why NetBSD shouldn't too.

I first reached out to the NetBSD toolchain developers[3]. They convinced me some alternate disambiguater (my first suggestion) wasn't worth it, with a.out being so old. But they did offer some tentative support for my second suggestion of changing the meaning of bare "netbsd" --- "netbsdaout" would still be available to unambiguously request a.out for anyone that wants it. I come now to just ask about that second suggestion.

I have prepared a first draft of patches for Binutils and GCC, but before polishing them off to submit, I figured I should ask about the openness to such a change.

Thanks,

John

[1]: I hope it's OK to email both lists at once like this; this is a question about a change that I think only makes sense if both projects approve.

[2] Nixpkgs, https://github.com/nixos/nixpkgs/

[3]: https://mail-index.netbsd.org/tech-toolchain/2021/06/10/msg003976.html this post goes more into more why I am interested in this change for anyone that's curious. Apologies for the duplicate emails; I thought the list was rejecting emails with HTML but it was something else.

Re: Making *-netbsd-* to mean ELF not a.out for all CPUs

[Nick Clifton]

Hi John,

> But they did offer some tentative support for my second suggestion of changing the meaning of bare "netbsd" --- "netbsdaout" would still be available to unambiguously request a.out for anyone that wants it.

I think that this would be OK for the binutils, providing that when configuring for
just "netbsd" there was a prominentant message in the config log saying something like:
"netbsd format now treated as ELF based.  Use netbsdaout if you want a.out format files".
(Probably with slightly better wording than that).

Cheers
   Nick

Re: Making *-netbsd-* to mean ELF not a.out for all CPUs

[Maciej W. Rozycki]

On Fri, 11 Jun 2021, John Ericson wrote:

> I would like to propose that GNU tools consistently interpret configs 
> with "netbsd" as meaning ELF as opposed to a.out. Currently, newer CPUs 
> do that, but older ones have "netbsd" mean a.out for historical reasons, 
> and "netbsdelf" is used instead. This inconsistency is a bit of a 
> nuisance to my distro / package set[2] which aims to support cross 
> compilation to/from arbitrary platforms without special cases. Other 
> platforms that formerly used a.out (like Linux) have long since changed 
> the default to be ELF, so I don't know why NetBSD shouldn't too.

 Have you verified that `config.guess' with DTRT to complement your change 
when indeed natively run on an old a.out installation of NetBSD?

  Maciej