Subject: Re: [PATCH 2/2] connector, linux++: fix <uapi/linux/cn_proc.h> header

From: Simon Horman <[email-masked]>
Date: Wed, 24 Jan 2024 08:40:27 +0000

On Tue, Jan 23, 2024 at 01:16:46PM +0300, Alexey Dobriyan wrote:
> Rules around enums are stricter in C++, they decay to ints just as
> easily but don't convert back to enums:
> 
> 	#define PROC_EVENT_ALL (PROC_EVENT_FORK|...)
> 	enum proc_cn_event ev_type;
> 	ev_type &= PROC_EVENT_ALL;
> 
> main.cc: In function ‘proc_cn_event valid_event(proc_cn_event)’:
> main.cc:91:17: error: invalid conversion from ‘unsigned int’ to ‘proc_cn_event’ [-fpermissive]
>    91 |         ev_type &= PROC_EVENT_ALL;
>       |                 ^
>       |                 |
>       |                 unsigned int
> 
> Use casts so that both C and C++ compilers are satisfied.
> 
> Signed-off-by: Alexey Dobriyan <[email-masked]>
> ---
> 
>  include/uapi/linux/cn_proc.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> --- a/include/uapi/linux/cn_proc.h
> +++ b/include/uapi/linux/cn_proc.h
> @@ -69,8 +69,7 @@ struct proc_input {
>  
>  static inline enum proc_cn_event valid_event(enum proc_cn_event ev_type)
>  {
> -	ev_type &= PROC_EVENT_ALL;
> -	return ev_type;
> +	return (enum proc_cn_event)(ev_type & PROC_EVENT_ALL)

Hi Alexey,

I think the line above needs a ; at the end of it.

>  }
>  /*
> -- 
> 2.43.0