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Date:   Thu, 26 May 2022 22:06:30 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     Eugenio Perez Martin <eperezma@redhat.com>
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Subject: Re: [PATCH v3 2/4] vhost-vdpa: introduce STOP backend feature bit
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On Thu, May 26, 2022 at 07:00:06PM +0200, Eugenio Perez Martin wrote:
> > It feels like returning any literal that isn't 1 or 0 should trigger a
> > warning...  I've written that and will check it out tonight.
> >
> 
> I'm not sure this should be so strict, or "literal" does not include pointers?
> 

What I mean in exact terms, is that if you're returning a known value
and the function returns bool then the known value should be 0 or 1.
Don't "return 3;".  This new warning will complain if you return a known
pointer as in "return &a;".  It won't complain if you return an
unknown pointer "return p;".

> As an experiment, can Smatch be used to count how many times a
> returned pointer is converted to int / bool before returning vs not
> converted?

I'm not super excited to write that code...  :/

> 
> I find Smatch interesting, especially when switching between projects
> frequently. Does it support changing the code like clang-format? To
> offload cognitive load to tools is usually good :).

No.  Coccinelle does that really well though.

regards,
dan carpenter