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: <1823e72eb92280d30457dda49e0a0036dee15dd3.camel@perches.com>
Subject: Re: [PATCH v4] checkpatch: add fix option for LOGICAL_CONTINUATIONS
From:   Joe Perches <joe@perches.com>
To:     Aditya Srivastava <yashsri421@gmail.com>
Cc:     lukas.bulwahn@gmail.com,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-kernel@vger.kernel.org
Date:   Sat, 21 Nov 2020 18:37:29 -0800
In-Reply-To: <20201121210442.17299-1-yashsri421@gmail.com>
References: <a6ee46ce01747627196478ff2a965d48dd4eed73.camel@perches.com>
         <20201121210442.17299-1-yashsri421@gmail.com>
Content-Type: text/plain; charset="ISO-8859-1"
User-Agent: Evolution 3.38.1-1 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Sun, 2020-11-22 at 02:34 +0530, Aditya Srivastava wrote:
> Currently, checkpatch warns if logical continuations are placed at the
> start of a line and not at the end of previous line.
> 
> E.g., running checkpatch on commit 3485507fc272 ("staging:
> bcm2835-camera: Reduce length of enum names") reports:
> 
> CHECK:LOGICAL_CONTINUATIONS: Logical continuations should be on the
> previous line
> +	if (!ret
> +	    && camera_port ==
> 
> Provide a simple fix by adding logical operator at the end of previous
> line and removing from current line, if both the lines are additions
> (ie start with '+')
> 
> Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
> ---
> changes in v2: quote $operator at substitution
> 
> changes in v3: add a check for previous line ending with comment;
> If so, insert $operator at the last non-comment, non-whitespace char of the previous line
> 
> changes in v4: improve the matching mechanism by matching line termination at comment or white space;
> insert the operator before comments (if any) separated by a whitespace;
> append the comment and its pre-whitespace after the inserted operator (if comment was present),
> ie if no comment was present nothing will be inserted after the operator

nak. I gave you a hint to the match string to use.

$prevline =~ /[\s$;]*$/

this matches either /* foo */ or // foo comment styles
(or optional blanks before EOL)

Try something like:
---
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index fab38b493cef..3c78cf0c219f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3434,8 +3434,15 @@ sub process {
 
 # check for && or || at the start of a line
 		if ($rawline =~ /^\+\s*(&&|\|\|)/) {
-			CHK("LOGICAL_CONTINUATIONS",
-			    "Logical continuations should be on the previous line\n" . $hereprev);
+			my $operator = $1;
+			if (CHK("LOGICAL_CONTINUATIONS",
+				"Logical continuations should be on the previous line\n" . $hereprev) &&
+			    $fix && $prevrawline =~ /^\+/) {
+				# add logical operator to the previous line, remove from current line
+				$prevline =~ /([\s$;]*$)/;
+				substr($fixed[$fixlinenr - 1], $-[0]) = " $operator" . substr($prevrawline, $-[0],$+[0]);
+				$fixed[$fixlinenr] =~ s/\Q$operator\E\s*//;
+			}
 		}
 
 # check indentation starts on a tab stop