[Cocci] position confusion?

[johannes@sipsolutions.net (Johannes Berg)]

On Sat, 2017-01-28 at 12:10 +0530, Vaishali Thakkar wrote:
> On Saturday 28 January 2017 04:40 AM, Johannes Berg wrote:
> > This is nonsense, but I don't see why it shouldn't parse:
> 
> Hi,
> 
> > @a@
> > type T;
> > identifier x;
> > position p;
> > @@
> > T x at p = { };
> > 
> > @b@
> > type T;
> > identifier x;
> > position p;
> 
> This should be "position p != a.p;".

That has no effect on the point I was trying to make. I told you the
spatch was nonsense ... :)

> > @@
> > T x at p = { };
> > 
> > @@
> > position p != a.p;
> > position q != b.p;
> 
> And here no need to put constraint for q.

There was no need to put a constraint anyway, again, the whole patch
made no sense. But assume I wanted to have p and q in different
positions, or whatever. Note that I didn't even *use* @p in the rule,
so you're making wrong assumptions.

> position p != {a.p, b.p};

Nevertheless, that's something I learned.

johannes