Re: [PATCH 0/2] First steps in making autoconf ensure a POSIX shell

[Stefano Lattarini]

On 11/10/2012 01:45 AM, Eric Blake wrote:
>
> [SNIP]
>
> What I'm thinking right now (but don't have the patch ready yet) is that
> we will reinstate a spy that loudly warns if autoconf can't find a POSIX
> shell, with a request for bug reports, and in parallel add a new macro
> (maybe named AS_SHELL_POSIX) that other packages can use to require a
> POSIX shell even with autoconf 2.70.  That is, using the new macro would
> switch autoconf from spying to requiring POSIX, but packages that aren't
> ready to require POSIX can still safely use 2.70, and the spy will help
> us know if anyone is really stuck on a non-museum system where it matters.
> 
This is a good idea.  It might also scale well in case we'll decide to
allow the user to request more POSIX or not-so-POSIX features from the
shell: that could be implemented with a similar macro AS_SHELL_EXTRA
(say), or, for finer control and granularity, by having AS_SHELL_POSIX
take arguments specifying extra suggested or required features:

    AS_SHELL_POSIX([
       set-x-dont-corrupt-stderr=suggested
       set-e-respects-exit-traps=required
    ])

Thanks,
  Stefano