Re: [RFC PATCH 4/4] llist.h: Fix parentheses around macro pointer parameter use

[Linus Torvalds]

On Fri, May 5, 2023 at 7:23 AM Mathieu Desnoyers
<mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>
> Is a list iteration position absolutely required to be a local variable,
> or can it be a dereferenced pointer ?

Well, it was certainly the intention, but while the member name
obviously has to be a member name, the iterator *could* be any lvalue.

Many of the "foreach" kind of loops would actually prefer to have
entirely local variables, but C syntax rules didn't allow that (now
with C11 we can do that variable declaration in the for-loop itself,
but we're still limited to just _one_ variable which can be a
problem).

So if we had started with C11, that 'list_for_each()' wouldn't have
had an external 'pos' declaration at all, it would have done it
internally, but that's not the reality we're in today ;/

              Linus