Akim Demaille wrote:
>
> >>>>> "Alexandre" == Alexandre Oliva <[EMAIL PROTECTED]> writes:
>
> Alexandre> On May 21, 2000, DEMAILLE Akim <[EMAIL PROTECTED]> wrote:
> >> This point is that if the user did not --build, then
> >> $build_alias='' likewise for the two others. Before, $build_alias
> >> would have been the same as as $build, i.e. computed by
> >> config.guess.
>
> Alexandre> I fear backward compatibility problems. What if
> Alexandre> configure.in refers to $build, $host or $target before
> Alexandre> calling AC_CANONICAL_*?
>
> To me that's a bug which would be revealed by this patch, but it's a
> bug in `configure.in'. Must we be bugward compatible?
bugward :)
I think so, cf. below.
> If so, we can
> set host to host_alias at the end of the handling of the options,
No, host and host_alias can differ, and configure script could
exploit this for whatever reason.
Eg. have a look at the output of the configure script below
(autoconf 2.13):
# cat configure.in
AC_INIT(Makefile.am)
echo "host:$host"
echo "build:$build"
echo "target:$target"
AC_CANONICAL_SYSTEM
AM_INIT_AUTOMAKE(test,0)
echo "host:$host host_alias:$host_alias"
echo "build:$build build_alias:$build_alias"
echo "target:$target target_alias:$target_alias"
AC_OUTPUT(Makefile)
# ./configure --host=sh-rtems --build=i386-linux --quiet
creating cache ./config.cache
host:sh-rtems
build:i386-linux
target:NONE
host:sh-unknown-rtems host_alias:sh-rtems
build:i386-pc-linux build_alias:i386-linux
target:sh-unknown-rtems target_alias:sh-rtems
updating cache ./config.cache
[..]
As you can see it makes an essential difference if using
$[host|build|target] or $*_alias :)
> but
> I'd rather not, since this is wrong from the semantics point of view:
> this would not be the right value of `host', and it would change right
> after AC_CANONICAL is called.
Another difference has been that host, build and target were present
all autoconf configure scripts by default, even if AC_CANONICAL_*
etc. had not been used in a configure.in. Therefore I assume, there
might exist configure scripts which rely on the values of host,
build, target without using AC_CANONICAL_*, esp. in packages not
using automake/config.guess/config.sub.
Ralf
--
Ralf Corsepius
Forschungsinstitut fuer Anwendungsorientierte Wissensverarbeitung
(FAW)
Helmholtzstr. 16, 89081 Ulm, Germany Tel: +49/731/501-8690
mailto:[EMAIL PROTECTED] FAX: +49/731/501-999
http://www.faw.uni-ulm.de
