Re: cocci script to convert linux-kernel allocs with BITS_TO_LONGS to bitmap_alloc

From: Joe Perches
Date: Sat Jul 10 2021 - 16:02:42 EST


On Sat, 2021-07-10 at 21:50 +0200, Julia Lawall wrote:
> On Fri, 9 Jul 2021, Joe Perches wrote:
>
> > Here is a cocci script to convert various types of bitmap allocations
> > that use BITS_TO_LONGS to the more typical bitmap_alloc functions.
> >
> > Perhaps something like it could be added to scripts/coccinelle.
> > The diff produced by the script is also below.
> >
> > $ cat bitmap_allocs.cocci
> > // typical uses of bitmap allocations
[]
> > @@
> > expression val;
> > expression e1;
> > expression e2;
> > @@
> >
> > - val = kcalloc(BITS_TO_LONGS(e1), sizeof(*val), e2)
> > + val = bitmap_zalloc(e1, e2)
>
> Is there something that guarantees that val has a type that has a size that
> is the same as a long?

no, but afaict, all do.