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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Thu, 26 Nov 2020 16:28:12 +0100
Message-ID: <CAMuHMdV5kOakvZJMWLxbpigFPS+Xuw6DVYsWCWZy7wGsv3idcw@mail.gmail.com>
Subject: Re: [PATCH 000/141] Fix fall-through warnings for Clang
To:     Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc:     Edward Cree <ecree.xilinx@gmail.com>,
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Hi Miguel,

On Thu, Nov 26, 2020 at 3:54 PM Miguel Ojeda
<miguel.ojeda.sandonis@gmail.com> wrote:
> On Wed, Nov 25, 2020 at 11:44 PM Edward Cree <ecree.xilinx@gmail.com> wrote:
> > To make the intent clear, you have to first be certain that you
> >  understand the intent; otherwise by adding either a break or a
> >  fallthrough to suppress the warning you are just destroying the
> >  information that "the intent of this code is unknown".
>
> If you don't know what the intent of your own code is, then you
> *already* have a problem in your hands.

The maintainer is not necessarily the owner/author of the code, and
thus may not know the intent of the code.

> > or does it flag up code
> >  that can be mindlessly "fixed" (in which case the warning is
> >  worthless)?  Proponents in this thread seem to be trying to
> >  have it both ways.
>
> A warning is not worthless just because you can mindlessly fix it.
> There are many counterexamples, e.g. many
> checkpatch/lint/lang-format/indentation warnings, functional ones like
> the `if (a = b)` warning...

BTW, you cannot mindlessly fix the latter, as you cannot know if
"(a == b)" or "((a = b))" was intended, without understanding the code
(and the (possibly unavailable) data sheet, and the hardware, ...).

P.S. So far I've stayed out of this thread, as I like it if the compiler
     flags possible mistakes.  After all I was the one fixing new
     "may be used uninitialized" warnings thrown up by gcc-4.1, until
     (a bit later than) support for that compiler was removed...

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds