Re: [PATCH] remove warning for --host without --build

[Peter Rosin]

On 2012-04-22 19:42, Bruno Haible wrote:
> Hi,
> 
> On bi-arch systems (such as x86 / x86_64) it is often necessary to pass
> the --host option together with an appropriate value for CC. But this
> triggers a warning:
> 
> $ ./configure --host=i686-pc-linux-gnu CC="gcc -m32 -march=i586"
> configure: WARNING: if you wanted to set the --build type, don't use --host.
>     If a cross compiler is detected then cross compile mode will be used
> ...

(CC on the configure line is not involved in triggering the warning)

> This warning was introduced on 2000-06-30, in commit
> <http://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=cb2e761b8e1181f97e8e09d85526bd22078433db>
> with the remark "Re-enable the old behavior of --host and --build."
> 
> This warning was meant to warn users about a changed semantics of
> --build and --host. This change is now 12 years in the past; users
> have had enough time to learn it. I therefore suggest to remove the
> warning.
> 
> I've done lots of cross and bi-arch compilations in the last 10 years,
> all with --host and without --build, and have never observed a problem
> with it, except for the warning. Simply relying on config.guess is sufficient.

If you don't specify --build when you are cross-compiling (i.e. host != build),
in an environment where the build system -- for one reason or another -- is able
to execute the host code, the heuristic to detect a cross-compiler fails.

So, maybe also change the

        checking whether we are cross compiling... yes/no

outcome to a simple $host != $build (or something along those lines) so that

        ./configure --host=whatever

is made more similar to

        ./configure --host=whatever --build=the-default

Cheers,
Peter