2020-11-25 23:27:27

by Finn Thain

[permalink] [raw]
Subject: Re: [Intel-wired-lan] [PATCH 000/141] Fix fall-through warnings for Clang

On Wed, 25 Nov 2020, Nick Desaulniers wrote:

> So developers and distributions using Clang can't have
> -Wimplicit-fallthrough enabled because GCC is less strict (which has
> been shown in this thread to lead to bugs)? We'd like to have nice
> things too, you know.
>

Apparently the GCC developers don't want you to have "nice things" either.
Do you think that the kernel should drop gcc in favour of clang?
Or do you think that a codebase can somehow satisfy multiple checkers and
their divergent interpretations of the language spec?

> This is not a shiny new warning; it's already on for GCC and has existed
> in both compilers for multiple releases.
>

Perhaps you're referring to the compiler feature that lead to the
ill-fated, tree-wide /* fallthrough */ patch series.

When the ink dries on the C23 language spec and the implementations figure
out how to interpret it then sure, enforce the warning for new code -- the
cost/benefit analysis is straight forward. However, the case for patching
existing mature code is another story.