Cross compilation, building cross-tools, canadian build

[Sylvain BERTRAND]

Hi,
I wanted to use the build, host, target options to compile a "natively 
cross-compiled"(namely from i686-pc-linux-gnu to i686-pc-linux-gnu) 
GNU/linux distribution.
But right at the beginning with the binutils I got stuck because:

1 - The build, host, target options are handled differently in autoconf 
2.13 than in the latest versions. And binutils, gcc use 2.13 autoconf 
scripts.

2 - In order to detect the build of cross tools or cross compiling or 
both, configure scripts do host, target, build comparison themselves. 
Then if the systems types are the same(in my case i686-pc-linux-gnu), I 
cannot trigger the right behavior without deeply dive in the 
configuration scripts modifying them.

I wonder what is the targeted final behavior for the build, host, target 
options: Is this already implemented is autoconf 2.57?
If so, what would involve the addition of flags and variables in order 
to force cross-compilation, building of cross-tools, or even the 
canadian way?
Or, merely, do I miss something?

Sylvain