Re: config.sub/config.guess using nonportable $(...) substitutions

[Nick Bowler]

On 09/03/2021, Warren Young <warren@etr-usa.com> wrote:
> On Mar 9, 2021, at 1:26 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
>>
>>> 1) There is no actual benefit to using $(...) over `...`.
>>
>> I disagree with that statement on technical grounds (not merely cosmetic
>> grounds), as I've run into real problems in using `...` along with " and
>> \,
>
> Me too, plus nesting.  The difference is most definitely not cosmetic.

I think what Karl means is that it is usually very easy to portably work
around the problems of nested and/or quoted `...` substitutions (usually
by just using a variable).

In other words, the difference between a script using $(...) and an
equivalent, more portable script using `...` is only one of appearance.

Regardless, there are no quoted or nested substitutions whatsoever in
config.sub.  I see exactly one nested substitution in config.guess, and
just a handful of quoted ones.  None appear particularly challenging to
write portably.

> Autoconf came out in 1991, so it’s the equivalent of supporting Version 6
> Unix (1975) in the original release, which it probably didn’t do, given that
> the Bourne shell didn’t even exist at that point.
>
> Are the malcontents not expecting heroic levels of backwards compatibility
> that Autoconf never has delivered?

No, I'm just expecting that things are not broken gratuitously in core
portability tools because someone does not like the appearance of the
more portable syntax.

I _especially_ don't expect this kind of breakage when upgrading from one
Automake point release to another (1.16.1 to 1.16.3).

Cheers,
  Nick