Re: [PATCH 000/141] Fix fall-through warnings for Clang

Karol Herbst
2020-11-26T16:18:52Z

On Thu, Nov 26, 2020 at 4:28 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> 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, ...).
>

to allow assignments in if statements was clearly a mistake and if you
need outside information to understand the code, your code is the
issue already.

> 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
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