Re: Improve AC_CACHE_VAL

[Paolo Bonzini]

> Does it need to be done with shell exec redirections, or is it possible to
> do it solely via m4 pushdef/popdef?

This is just what I had on my hard disk. :-)  But yes, probably shell
is better now that I think of it.

> I agree with Ralf's comments - since AS_MESSAGE_FD is an m4sh construct,
> the push/pop silence macros belong in m4sh.  Which means, for convenience,
> we should then provide AC_CACHE_VAL_SILENT that does the push/pop itself.

More likely AC_CACHE_CHECK_SILENT.

Paolo