Re: [PATCH] use m4_require to implement AS_REQUIRE

[Ralf Wildenhues]

Hi Paolo,

* Paolo Bonzini wrote on Sun, Oct 12, 2008 at 06:20:53PM CEST:
> Hi, I know I should be writing testcases for AS_ME_PREPARE. :-) But
> while I was looking at adding shell functions to Autoconf proper, I
> decided that the current basic implementation of AS_REQUIRE is not
> scalable.
> 
> In particular, AC_CHECK_FUNC will need its own shell function, plus
> the one for AC_LINK_IFELSE.  If AC_LINK_IFELSE has not been expanded yet,
> then something like this comes out of m4:
> 
>   ac_c_check_func() {
>     if test $ac_cv...; then
>       ...
>     else
>       ac_c_link_ifelse() {
>       }
>     fi
>   }
> 
> which does not work of course.

For me mere mortal, who doesn't wade in the problems you've studied in
detail, what exactly is problematic here?
(Not that I expect to review your patch, but I kind of hope the question
would be easy and quick for you anyway)

Thanks!
Ralf