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

[Bruno Haible]

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
...

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.

Therefore I suggest to remove the warning:


2012-04-22  Bruno Haible  <address@hidden>

        AC_INIT: Remove a transitional warning.
        * lib/autoconf/general.m4 (_AC_INIT_PARSE_ARGS): Don't warn if --host
        given without --build.

--- lib/autoconf/general.m4.orig        Sun Apr 22 19:22:42 2012
+++ lib/autoconf/general.m4     Sun Apr 22 19:22:27 2012
@@ -949,8 +949,6 @@
 if test "x$host_alias" != x; then
   if test "x$build_alias" = x; then
     cross_compiling=maybe
-    AC_MSG_WARN([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])
   elif test "x$build_alias" != "x$host_alias"; then
     cross_compiling=yes
   fi