Re: [PATCH] Makefile: Convert -Wimplicit-fallthrough=3 to just -Wimplicit-fallthrough for clang

From: Nathan Chancellor
Date: Sat Aug 10 2019 - 22:04:54 EST


On Sat, Aug 10, 2019 at 01:18:22PM -0700, Joe Perches wrote:
> On Sat, 2019-08-10 at 12:44 -0700, Linus Torvalds wrote:
> > On Sat, Aug 10, 2019 at 12:32 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > > What does it take for this sort of patch to be applied by you?
> >
> > The basic rule tends to be: "normal channels".
> []
> > I pulled from Gustavo earlier today to add a few more expected switch
> > fall-through's, I guess I can take this Makefile change directly.
>
> Thanks. It's simple enough.
>
> There are classes of patches generated by scripts that have
> no real mechanism to be applied today.
>
> For instance: global coccinelle scripted changes to use stracpy
> https://lore.kernel.org/lkml/alpine.DEB.2.21.1907251747560.2494@hadrien/
>
> and trivial scripted changes to MAINTAINERS
> https://lore.kernel.org/lkml/6482e6546dc328ec47b07dba9a78a9573ebb3e56.camel@xxxxxxxxxxx/
>
> that are basically impossible to be applied by anyone but you.
>
> Otherwise there are hundreds of little micro patches most of
> which would not otherwise be applied.
>
> There should be some process available to get these treewide
> or difficult to keep up-to-date and apply patches handled.
>
> I believe these sorts of scripted patches should ideally
> be handled immediately before an RC1 so other trees can be
> synchronized in the simplest way possible.
>

Hi Joe,

On a tangential note, how are you planning on doing the fallthrough
comment to attribute conversion? The reason I ask is clang does not
support the comment annotations, meaning that when Nathan Huckleberry's
patch is applied to clang (which has been accepted [1]), we are going
to get slammed by the warnings. I just ran an x86 defconfig build at
296d05cb0d3c with his patch applied and I see 27673 instances of this
warning... (mostly coming from some header files so nothing crazy but it
will be super noisy).

If you have something to share like a script or patch, I'd be happy to
test it locally.

[1]: https://reviews.llvm.org/D64838

Cheers,
Nathan