with_cross_host vs cross-hosted

[Daniel Jacobowitz]

On Thu, Jul 05, 2001 at 02:55:48PM -0400, DJ Delorie wrote:
> 
> My linux-cygwin-cygwin builds have been failing, and I finally took
> the time to track it down.  In libstdc++-v3, configure uses
> ${with_cross_host} to choose whether we run a program to generate
> std_limits.h, or use default values.  Nobody ever sets
> ${with_cross_host}.  I modified configure to explicitly test the
> build, host, and target values.  Has anyone had any success
> cross-building a native?

No.  I posted about this a couple of weeks ago.  Your patch is wrong;
once we're building libstdc++, $host is what is normally considered
$target, and $target is undefined.  --with-cross-host is actually
passed by the toplevel configure if $host != $target, to preserve the
missing piece of information.

> ! if test -n "$with_cross_host"; then

> ! if test "$build $build" != "$host $target"; then

How about 'if test x"$build" != x"$host"' ?  We don't really care what
the compiler's host will be, just what the library's host/target will
be.  If you're compiling x86-linux -> sparc-solaris -> x86-linux, I
don't see anything wrong with running the tests natively.

> ***************
> *** 83,87 ****
>     # If Canadian cross, then don't pick up tools from the build
>     # directory.
> !   if test x"$build" != x"$with_cross_host" && x"$build" != x"$target"; then
>       CANADIAN=yes
>       NULL_TARGET=yes
> --- 85,89 ----
>     # If Canadian cross, then don't pick up tools from the build
>     # directory.
> !   if test x"$build" != x"$host" && x"$build" != x"$target"; then
>       CANADIAN=yes
>       NULL_TARGET=yes
> 

You hit the missing "test" there too :)  Plus, as I mentioned, $target
can't be trusted at this point.

Does 'if test x"$build" != x"$with_cross_host" && test x"$build" !=
x"$host"' work for you?  That's presumably the right test for a true
Canadian cross.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer