Re: [PATCH RESEND][next] rtl8xxxu: Fix fall-through warnings for Clang

On Wed, Mar 10, 2021 at 02:31:57PM -0500, Jes Sorensen wrote:

On 3/10/21 2:14 PM, Kees Cook wrote:

quoted

On Fri, Mar 05, 2021 at 03:40:33PM +0200, Kalle Valo wrote:

quoted

"Gustavo A. R. Silva" [off-list ref] writes:

quoted

In preparation to enable -Wimplicit-fallthrough for Clang, fix
multiple warnings by replacing /* fall through */ comments with
the new pseudo-keyword macro fallthrough; instead of letting the
code fall through to the next case.

Notice that Clang doesn't recognize /* fall through */ comments as
implicit fall-through markings.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

It's not cool that you ignore the comments you got in [1], then after a
while mark the patch as "RESEND" and not even include a changelog why it
was resent.

[1] https://patchwork.kernel.org/project/linux-wireless/patch/d522f387b2d0dde774785c7169c1f25aa529989d.1605896060.git.gustavoars@kernel.org/

Hm, this conversation looks like a miscommunication, mainly? I see
Gustavo, as requested by many others[1], replacing the fallthrough
comments with the "fallthrough" statement. (This is more than just a
"Clang doesn't parse comments" issue.)

This could be a tree-wide patch and not bother you, but Greg KH has
generally advised us to send these changes broken out. Anyway, this
change still needs to land, so what would be the preferred path? I think
Gustavo could just carry it for Linus to merge without bothering you if
that'd be preferred?

I'll respond with the same I did last time, fallthrough is not C and
it's ugly.

I understand your point of view, but this is not the consensus[1] of
the community. "fallthrough" is a macro, using the GCC fallthrough
attribute, with the expectation that we can move to the C17/C18
"[[fallthrough]]" statement once it is finalized by the C standards
body.

-Kees

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#implicit-switch-case-fall-through

-- 
Kees Cook