linux-kernel - Re: [PATCH v2] checkpatch: add check for continue statement in UNNECESSARY

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Message-ID: <d15bba541aac03ebe24c733f24b6bda96d03a3ec.camel@perches.com>
Date:   Fri, 01 Oct 2021 14:09:18 -0700
From:   Joe Perches <joe@...ches.com>
To:     Utkarsh Verma <utkarshverma294@...il.com>,
        Andy Whitcroft <apw@...onical.com>
Cc:     Dwaipayan Ray <dwaipayanray1@...il.com>,
        Lukas Bulwahn <lukas.bulwahn@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] checkpatch: add check for continue statement in
 UNNECESSARY_ELSE

On Sat, 2021-10-02 at 02:17 +0530, Utkarsh Verma wrote:
> UNNECESSARY_ELSE only checks for the usage of else after a return or
> break. But the same logic is also true for continue statement.
> 
> else used after a continue statement is unnecessary. So add a test
> for continue statement also.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -4011,15 +4011,15 @@ sub process {
>  
> 
>  # check indentation of any line with a bare else
>  # (but not if it is a multiple line "if (foo) return bar; else return baz;")
> -# if the previous line is a break or return and is indented 1 tab more...
> +# if the previous line is a break or continue or return and is indented 1 tab more...
>  		if ($sline =~ /^\+([\t]+)(?:}[ \t]*)?else(?:[ \t]*{)?\s*$/) {
>  			my $tabs = length($1) + 1;
> -			if ($prevline =~ /^\+\t{$tabs,$tabs}break\b/ ||
> +			if ($prevline =~ /^\+\t{$tabs,$tabs}(?:break|continue)\b/ ||
>  			    ($prevline =~ /^\+\t{$tabs,$tabs}return\b/ &&
>  			     defined $lines[$linenr] &&
>  			     $lines[$linenr] !~ /^[ \+]\t{$tabs,$tabs}return/)) {
>  				WARN("UNNECESSARY_ELSE",
> -				     "else is not generally useful after a break or return\n" . $hereprev);
> +				     "else is not generally useful after a break or continue or return\n" . $hereprev);
>  			}
>  		}
>  
> 

Maybe make the output specific to the break/continue/return
(untested)

			if ($prevline =~ /^\+\t{$tabs,$tabs}(break|continue|return)\b/ &&
			    !($1 == "return" &&
			      defined $lines[$linenr] &&
			      $lines[$linenr] !~ /^[ \+]\t{$tabs,$tabs}return/)) {
				WARN("UNNECESSARY_ELSE",
				     "else is not generally useful after a $1\n" . $hereprev);