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

[Theodore Y. Ts'o]

On Sun, Oct 21, 2018 at 07:14:13PM +0200, Miguel Ojeda wrote:
> From the GCC manual:
> 
>   fallthrough
> 
>     The fallthrough attribute with a null statement serves as a
>     fallthrough statement. It hints to the compiler that a statement
>     that falls through to another case label, or user-defined label
>     in a switch statement is intentional and thus the -Wimplicit-fallthrough
>     warning must not trigger. The fallthrough attribute may appear
>     at most once in each attribute list, and may not be mixed with
>     other attributes. It can only be used in a switch statement
>     (the compiler will issue an error otherwise), after a preceding
>     statement and before a logically succeeding case label,
>     or user-defined label.
> 
>   https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html

Do we know if coverity understands the fallthrough attribute?  One of
the reasons why I started using /* fallthrough */ is because it kept
Coverity happy.

If the conversion from /* fallthrough */ to the __fallthrough__
attribute means that we start gethting a lot of Coverity warnings,
that would be unfortunate.  OTOH, if this is getting standardized,
maybe we can get Coverity to understand this attribute?

						- Ted