Re: [PATCH v6] coccinelle: api: add kvfree script

From: Julia Lawall
Date: Mon Aug 03 2020 - 08:12:51 EST

On Mon, 3 Aug 2020, Denis Efremov wrote:

> Is there a difference from cocci point of view between:
> ... when != !is_vmalloc_addr(E)

This will only reject cases where the ! is present. Coccinelle doesn't
apply isomorphisms to the C source code, so it doesn't detect that eg

if (A)
else C

could be rewritten as

if (!A)
ese B

So when != !A would only match when the code is in the second form.
> and
> ... when != is_vmalloc_addr(E)
> Should the latter one be used in most cases?

This matches both a call to is_vmalloc_addr and a negated call, so it is
more general.