Re: [PATCH] clk: samsung: s3c2443: Mark expected switch fall-through
From: Stephen Boyd <sboyd@kernel.org>
Date: 2019-02-16 00:34:52
Also in:
linux-clk, linux-samsung-soc, lkml
Quoting Kees Cook (2019-02-12 10:57:05)
On Mon, Feb 11, 2019 at 11:41 PM Krzysztof Kozlowski [off-list ref] wrote:quoted
It is just the GCC which has to be fixed not the code. You want to adjust the code for specific version of GCC and what if GCC changes its warning? For example GCC might require "fall through: "... or any other syntax. Another point - what about clang's syntax?-Wimplicit-fallthrough=3 is stricter and maps to -Wextra, hence its choice. GCC's levels were chosen based on the existing linters, static analyzers, etc. The patterns are unlikely to change (see the gcc man-page). Clang doesn't recognize anything in C mode (hopefully this will be fixed in the future[1]). As long as one of the compilers is able to check this, we'll avoid the bugs associated with this mis-pattern. Gustavo's efforts here have found kind of a lot of bugs, so I think it's worth a little churn to add these (and make minor adjustments to existing comments).
Just curious, what compilation phase does this check run in? Could we gain a macro like FALLTHRU or even lowercase 'fallthru' that expanded to whatever the compiler wants to see and then there would only be "one way" to do this? It would alleviate the above concerns, but maybe I'm rehashing something that's already been proposed and rejected. Of course, I'm happy to merge any of these patches that tweak things so no worries either way. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel