On Tue, 28 Nov 2017, Thomas Gleixner wrote: +CC Linus.
> On Tue, 28 Nov 2017, Thomas Gleixner wrote: > > > On Tue, 28 Nov 2017, Gustavo A. R. Silva wrote: > > > Quoting Thomas Gleixner <t...@linutronix.de>: > > > > > To be honest, such comments annoy me during a code review especially > > > > > when > > > > > the fallthrough is so obvious as in this case. There might be cases > > > > > where > > > > > its worth to document because it's non obvious, but documenting the > > > > > obvious > > > > > just for the sake of documenting it is just wrong. > > > > > > > > > > I understand that and I agree that in this particular case it is just > > > obvious. > > > The thing is that if we want to benefit from having the compiler help us > > > to > > > spot these kind of issues before committing our code, we have to address > > > every > > > place in the whole code-base. > > > > > > > And _IF_ at all then you want a fixed macro for this and not a comment > > > > which will be formatted as people see it fit. > > > > > > > > GCC supports: __attribute__ ((fallthrough)) which we can wrap into a > > > > macro, > > > > e.g. falltrough() > > > > > > > > That'd be useful, but adding all these comments and then having to > > > > chase a > > > > gazillion of warning instances to figure out whether there is a comment > > > > or > > > > not is just backwards. > > > > > > > > > > I have run into this before and people find what you suggest even uglier. > > > > It's not about ugly. It's about _USEFULL_. > > > > The comments are ugly AND completely useless for the compiler and they are > > going to be malformatted so checker tools can't differentiate the false > > positives. > > > > The macro, in which more or less ugly form written, is both documentation > > and helps the compiler NOT to emit the same crap over and over. > > Just checked and GCC really supports analyzing the comment to some extent. > > But just look at > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77817 > > " It is not really possible. __attribute__((fallthrough)) has precise > rules on where it can appear, while /* FALLTHRU */ comments, being > comments, can appear anywhere. Especially with -Wimplicit-fallthrough=1 > when all comments are considered fallthru comments... " > > I have no idea who came up with that brilliant idea of parsing comments in > the code. It's so simple to make this parser completely fail that it's not > even funny anymore. > > I don't care what other people prefer. The code base I'm responsible for > gets either proper annotations or nothing. And in fact we want ONE solution for the whole kernel. And comments are obviously the wrong one. Thanks, tglx
