Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <d15bba541aac03ebe24c733f24b6bda96d03a3ec.camel@perches.com>
Subject: Re: [PATCH v2] checkpatch: add check for continue statement in
 UNNECESSARY_ELSE
From:   Joe Perches <joe@perches.com>
To:     Utkarsh Verma <utkarshverma294@gmail.com>,
        Andy Whitcroft <apw@canonical.com>
Cc:     Dwaipayan Ray <dwaipayanray1@gmail.com>,
        Lukas Bulwahn <lukas.bulwahn@gmail.com>,
        linux-kernel@vger.kernel.org
Date:   Fri, 01 Oct 2021 14:09:18 -0700
In-Reply-To: <20211001204705.7448-1-utkarshverma294@gmail.com>
References: <91569a87ac55da392fa894e8ad55292b98c558f3.camel@perches.com>
         <20211001204705.7448-1-utkarshverma294@gmail.com>
Content-Type: text/plain; charset="ISO-8859-1"
User-Agent: Evolution 3.40.0-1 
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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);