On 21 Apr 2000, Akim Demaille wrote:
> >>>>> "Alexandre" == Alexandre Oliva <[EMAIL PROTECTED]> writes:
>
> Alexandre> Sounds good to me (i.e., you've got one approval; a patch
> Alexandre> needs two to be installed in the autoconf CVS tree).
>
> I confess I'm a bit lost by the change. We're moving from
>
> ac_cv_host_alias=`$ac_config_guess`
> ac_cv_build_alias=$host_alias
> ac_cv_target_alias=$host_alias
>
> to
>
> ac_cv_host_alias=`$ac_config_guess`
> ac_cv_build_alias=`$ac_config_guess`
> ac_cv_target_alias=$target_alias
The "alias" is the thing that the user could have passed
in on the command line. In the case of the host you
could pass in i586-cygwin32 and get the target_alias set
to that but the target would be i586-pc-cygwin32.
> I don't understand why this helps: how can we define target_alias in
> terms of ac_cv_target_alias since it appears to me that it is the
> converse that happen? See the code:
>
> | ...
> | $1=$ac_cv_$1
> | $1_alias=$ac_cv_$1_alias
> | $1_cpu=$ac_cv_$1_cpu
> | $1_vendor=$ac_cv_$1_vendor
> | $1_os=$ac_cv_$1_os
> | ...
> | ])# _AC_CANONICAL_THING
If the build test was always done then the result of that could
be used when figuring out the host. The host would not need to
do another config.guess in that case.
I hope that helps
Mo DeJong
Red Hat Inc.
> Also, how do we still guarantee a valid default for
> ac_cv_target_alias? Why do we need to run twice config.guess instead
> of propagating ac_cv_build_alias=$host_alias?
>
>
> Personally, I'd like better that thing to be written with an m4_case,
> it is becoming hardly readable. For instance before Mo's patch it
> would have been:
>
> ...
> NONE)
> m4_case([$1],
> [host],
> [ac_cv_host_alias=`$ac_config_guess` ||
> AC_MSG_ERROR(cannot guess host type; you must specify one)],
> [target],
> [ac_cv_target_alias=$host_alias],
> [build],
> [ac_cv_build_alias=$host_alias])
> *) ac_cv_$1_alias=$nonopt ;;
> ...
>
> Akim
>
