On Wed, 17 Oct 2012, Manuel López-Ibáñez wrote:

> documentation but I can also implement -Wformat=0 being an alias for
> -Wno-format and -Wformat=1 an alias for -Wformat and simply reject
> -Wno-format=.

I think that's what's wanted; -Wno-format= should be rejected, -Wformat= 
should take an arbitrary integer level (of which at present all those 
above 2 are equivalent to 2, just as -O<n> for n > 3 is equivalent to 
-O3).

-- 
Joseph S. Myers
joseph@codesourcery.com