Re: [PATCH v2 7/7] checkpatch: suggest _BITULL() and _BITUL() for UAPI headers

[Joe Perches <joe@perches.com>]

On Fri, 2021-05-21 at 01:58 -0700, Joe Richey wrote:
> From: Joe Richey <joerichey@google.com>
> 
> Instead of just ignoring UAPI headers, reccomend the UAPI compatible
> macros if a user adds something that looks like (1 << n). Normal kernel
> code will continue to get BIT_ULL() and BIT() reccomended.
> 
> This change also modifies the $realfile regex to match headers that have
> "include/uapi" anywhere in their path so paths like:
>     tools/include/uapi/linux/kvm.h
>     arch/x86/include/uapi/asm/hwcap2.h
> get recognized as UAPI headers.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -7020,15 +7020,17 @@ sub process {
>  			}
>  		}
>  
> 
> -# check for #defines like: 1 << <digit> that could be BIT(digit), it is not exported to uapi
> -		if ($realfile !~ m@^include/uapi/@ &&
> -		    $line =~ /#\s*define\s+\w+\s+\(?\s*1\s*([ulUL]*)\s*\<\<\s*(?:\d+|$Ident)\s*\)?/) {
> -			my $ull = "";
> -			$ull = "_ULL" if (defined($1) && $1 =~ /ll/i);
> +# check for #defines like: 1 << <digit> that could be BIT(digit) or similar
> +		if ($line =~ /#\s*define\s+\w+\s+\(?\s*1\s*([ulUL]*)\s*\<\<\s*(?:\d+|$Ident)\s*\)?/) {
> +			my $ull = (defined($1) && $1 =~ /ll/i);
> +			my $macroname = $ull ? "BIT_ULL" : "BIT";
> +			if ($realfile =~ m@include/uapi/@) {

Likely better with \b
			if ($realfile =~ m@\binclude/uapi/@) {

> +				$macroname = $ull ? "_BITULL" : "_BITUL";
> +			}
>  			if (CHK("BIT_MACRO",
> -				"Prefer using the BIT$ull macro\n" . $herecurr) &&
> +				"Prefer using the $macroname macro\n" . $herecurr) &&
>  			    $fix) {
> -				$fixed[$fixlinenr] =~ s/\(?\s*1\s*[ulUL]*\s*<<\s*(\d+|$Ident)\s*\)?/BIT${ull}($1)/;
> +				$fixed[$fixlinenr] =~ s/\(?\s*1\s*[ulUL]*\s*<<\s*(\d+|$Ident)\s*\)?/${macroname}($1)/;

Doesn't need braces
				$fixed[$fixlinenr] =~ s/\(?\s*1\s*[ulUL]*\s*<<\s*(\d+|$Ident)\s*\)?/$macroname($1)/;

Otherwise, fine by me.