Re: [PATCH] bitfield.h: add FIELD_MAX_CONST

[Jakub Kicinski]

On Mon, 20 May 2024 12:29:54 -0700 Yury Norov wrote:
> > A simplified example of what I actually want to use in a driver:
> >   #define DATA_SIZE_M GENMASK(3, 0)
> >   #define MAX_DATA_SIZE FIELD_MAX_CONST(DATA_SIZE_M)
> >   static void f(void) {
> >   	char buf[MAX_DATA_SIZE];

You need a "+ 1" somewhere here, right?

> >   }
> > 
> > In the implementation, reuse the existing compile-time checks from
> > FIELD_PREP_CONST.
> > 
> > Signed-off-by: Michal Schmidt <mschmidt@xxxxxxxxxx>  
> 
> Hi Michal,
> 
> So... FIELD_MAX() already requires the _mask to be a const value.
> Now you add a FIELD_MAX_CONST(), which makes it more confusing.

+1, I think this is doing too much in general.