Re: [PATCH] Use fall-through attribute rather than magic comments

From: Joe Perches
Date: Mon Jun 17 2019 - 12:30:57 EST


On Mon, 2019-06-17 at 17:56 +0200, Pavel Machek wrote:
> Hi!
>
> > +/*
> > + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wimplicit-fallthrough
> > + * gcc: https://developers.redhat.com/blog/2017/03/10/wimplicit-fallthrough-in-gcc-7/
> > + */
> > +#if __has_attribute(__fallthrough__)
> > +# define __fallthrough __attribute__((__fallthrough__))
> > +#else
> > +# define __fallthrough
> > +#endif
>
> Is it good idea to add the __'s ? They look kind of ugly.

Dunno.

I agree it's kind of ugly, but it should always work.

I think the generic problem is introducing a new unprefixed
reserved identifier. Underscored identifiers are reserved.

There is already a fallthrough: label used in kernel sources
in net/sctp/sm_make_chunk.c that should probably be changed.