How to enable Mudflap in gcc 4.x?

[Deepen Mantri]

Eric Christopher wrote:

>No, at the toplevel (just like your normal build of the compiler and  
>target libraries):
>configure --enable-languages=c --disable-multilib --enable-libmudflap  
>--target=sh-elf ; make -j8 all-gcc all-target

>and you'll get this:
>configure: error: none of the known symbol names works
>make: *** [configure-target-libmudflap] Error 1

>which means that libmudflap needs to be ported to sh-elf.

How should I start the porting? Do you have any document related to such
porting? I would really appreciate your help if you could guide me in
this.