Re: [PATCH 1/2] Compiler Attributes: add support for __fallthrough (gcc >= 7.1)

[Miguel Ojeda]

On Mon, Oct 22, 2018 at 11:36 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> We need to make sure the static analyzers are happy with either
> method. Additionally, when was -Wimplicit-fallthrough added to GCC? If
> it was added _before_ the attribute, we need to continue using the
> comment style otherwise we lose coverage even with gcc itself.
> Additionally, does Clang support this attribute (it supports
> -Wimplicit-fallthrough).

Please take a look at the rationale (also more details at the linked thread):

  * gcc 7.1 added -Wimplicit-fallthrough at the same time as the
attribute and the comment parsing.
  * clang does *not* support the attribute in C.

Cheers,
Miguel