Re: [PATCH net-next v2] checkpatch: warn about uses of ENOTSUPP

[Joe Perches]

On Mon, 2020-05-11 at 09:53 -0700, Jakub Kicinski wrote:
> ENOTSUPP often feels like the right error code to use, but it's
> in fact not a standard Unix error. E.g.:
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -4199,6 +4199,17 @@ sub process {
>  			     "ENOSYS means 'invalid syscall nr' and nothing else\n" . $herecurr);
>  		}
>  
> +# ENOTSUPP is not a standard error code and should be avoided in new patches.
> +# Folks usually mean EOPNOTSUPP (also called ENOTSUP), when they type ENOTSUPP.
> +# Similarly to ENOSYS warning a small number of false positives is expected.
> +		if (~$file && $line =~ /\bENOTSUPP\b/) {

It's probably my typo or my brain thinking "not" and hitting
the tilde and not the bang, but this should be

		if (!$file & ...)

Otherwise:

Acked-by: Joe Perches <joe@xxxxxxxxxxx>

> +			if (WARN("ENOTSUPP",
> +				 "ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP\n" . $herecurr) &&
> +			    $fix) {
> +				$fixed[$fixlinenr] =~ s/\bENOTSUPP\b/EOPNOTSUPP/;
> +			}
> +		}
> +
>  # function brace can't be on same line, except for #defines of do while,
>  # or if closed on same line
>  		if ($perl_version_ok &&