Messages in this thread | | | Subject | Re: [PATCH] usbip: Use fallthrough pseudo-keyword | From | Shuah Khan <> | Date | Wed, 8 Jul 2020 08:42:26 -0600 |
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On 7/8/20 4:16 AM, Julia Lawall wrote: > > > On Tue, 7 Jul 2020, Joe Perches wrote: > >> On Tue, 2020-07-07 at 14:06 -0600, Shuah Khan wrote: >>> On 7/7/20 1:52 PM, Gustavo A. R. Silva wrote: >>>> Replace the existing /* fall through */ comments and its variants with >>>> the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary >>>> fall-through markings when it is the case. >>>> >>>> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through >>>> >>> >>> Is fallthrough syntax supported on our min gcc version? >> >> No. Introduced in gcc 7. >> >>> Does checkpatch or coccicheck catch these cases? >> >> Kinda. checkpatch isn't very good at it. >> I _believe_, though I'm not at all sure, >> that coccinelle can find these. > > I would not guarantee anything about the support of Coccinelle for switch. > Coccinelle does now have the ability to match on comments. So since there > is a distinct comment that it is to be removed, it might be possible to do > that part automatically. > > Maybe it would have to look something like this: > > @r1@ > comments c : script:python() { code to recognize the comment }; > statement S; > @@ > > S@c > + fallthrough(); //or whatever is wanted > > @@ > statement r1.S; > @@ > > - S > - fallthrough(); > + S > + fallthrough(); > > The second rule probably looks pretty strange, but the goal is to remove > the comments between S and fallthrough(); > > There is an example demos/comments.cocci that shows how to access the > comment information using both ocaml and python. >
Thanks Julia. Maybe this is a way to address all of the cases. I am a bit concerned about min gcc which is 4.8 and the fallthrough syntax support is in gcc 7
-- Shuah
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