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

From: Bernd Petrovitsch
Date: Mon Oct 22 2018 - 05:48:15 EST

On 22/10/2018 00:27, Theodore Y. Ts'o wrote:
> 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.
> Do we know if coverity understands the fallthrough attribute? One of
> the reasons why I started using /* fallthrough */ is because it kept
> Coverity happy.

FWIW, current "eclipse" has the same "problem".

> If the conversion from /* fallthrough */ to the __fallthrough__
> attribute means that we start gethting a lot of Coverity warnings,

We could keep both.

Bernd Petrovitsch Email : bernd@xxxxxxxxxxxxxxxxxxx