Re: [PATCH] x86/syscalls: Mark expected switch fall-throughs

From: Gustavo A. R. Silva
Date: Tue Nov 28 2017 - 15:37:22 EST



Quoting Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>:

On Tue, Nov 28, 2017 at 11:00 AM, Alan Cox <gnomes@xxxxxxxxxxxxxxxxxxx> wrote:

The notation in question has been standard in tools like lint since the
end of the 1970s

Yes.

That said, maybe one option would be to annotate the "case:" and
"default:" statements if that makes people happier.

IOW, we could do something like

#define fallthrough __atttibute__((fallthrough))

and then write

fallthrough case 1:
...

which while absolutely not traditional, might look and read a bit more
logical to people. I mean, it literally _is_ a "fallthrough case", so
it makes semantic sense.


This is elegant. The thing is that this makes it appear as if there is an unconditional fall through.

It is not uncommon to have multiple break statements in the same case block and to fall through also.

Thanks
--
Gustavo A. R. Silva