netdev - Re: [PATCH 2/6] treewide: remove using list iterator after loop body as a ptr

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Message-ID: <e3bb7d0632f8ef60f18c19976d57330e1ef00584.camel@sipsolutions.net>
Date:   Mon, 28 Feb 2022 21:27:13 +0100
From:   Johannes Berg <johannes@...solutions.net>
To:     Matthew Wilcox <willy@...radead.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>
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Subject: Re: [PATCH 2/6] treewide: remove using list iterator after loop
 body as a ptr

On Mon, 2022-02-28 at 20:16 +0000, Matthew Wilcox wrote:
> On Mon, Feb 28, 2022 at 12:10:24PM -0800, Linus Torvalds wrote:
> > We can do
> > 
> >         typeof(pos) pos
> > 
> > in the 'for ()' loop, and never use __iter at all.
> > 
> > That means that inside the for-loop, we use a _different_ 'pos' than outside.
> 
> Then we can never use -Wshadow ;-(  I'd love to be able to turn it on;
> it catches real bugs.
> 

I was just going to say the same thing...

If we're willing to change the API for the macro, we could do

  list_for_each_entry(type, pos, head, member)

and then actually take advantage of -Wshadow?

johannes