Bernard Dautrevaux wrote:
>
> BTW, having such an automatic default option shoudl be nice for almost all
> tests; I know I can just "ac_c_bigendian=yes ./configure" but I never knows
> the name of the config.cache variables, so "./configure --set-bigendian=yes"
> coudl do the same.
a pre-setting of the cache-variables has no chance to go into a
`make reconfigure` line. Same with pre-setting $CC or $CFLAGS which one usually
does with crosscompiled autoconf. The usage of "--set-bigendian" would be of
course a nice thing, but you could not go with an overall setting for all the
autoconf package, since some packages may not have an AC_BIGENDIAN. It is
therefore needed to have some "--ac-<def>=xxx" that would be silently accept
any <def> even if not used anywhere in configure.
>
> Anyway in both cases what would *really* be needed is when a test like that
> fails would be to add a disgnostic line like "If you know the answer, just
> rerun configure witn option '--set-bigendian=yes'" or "... by typing
> 'ac_c_bigendian=yes ./configure'".
>
> This should not be too hard to do (disclaimer: I'm *not* an M4 programmer)
> and will make the life of cross-compiler-based installers a lot easier :-)
>
Well, it would not be too hard, but it would not solve problems of any
similar scheme. Perhaps have a generic AC_OPTION(defname [,explanation]),
that would go with --ac-defname, but I dunno how to really design it. <sigh>.
As for cross-compiling, I'd ask if there is a pre-include option, e.g.
--include=<pathtoshellscript>, where the script could hold the various
cache-variables to be preset, or even start to preset $CC. This option
would also go into the `make reconfigure`, so all you need is a (global)
script that has all the cache-variables at hand for the target-platforms
that are available in the lab (which is of limited number surely).
If there is no such option (not that is AFAIK), it should be added IMHO.
have fun...
-- Guido
