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From:   Julius Werner <jwerner@chromium.org>
To:     Andy Whitcroft <apw@canonical.com>, Joe Perches <joe@perches.com>
Cc:     linux-kernel@vger.kernel.org, Julius Werner <jwerner@chromium.org>
Subject: [PATCH v2 3/3] checkpatch: Ignore labels when checking indentation
Date:   Wed, 26 May 2021 19:26:24 -0700
Message-Id: <20210527022624.1034423-4-jwerner@chromium.org>
In-Reply-To: <20210527022624.1034423-1-jwerner@chromium.org>
References: <20210527022624.1034423-1-jwerner@chromium.org>
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Goto labels are commonly written in the leftmost column (sometimes with
one space in front), regardless of indentation level. Sometimes they're
on a line of their own, but sometimes the same line is shared with a
normal code statement that then starts at the expected indentation
level. When checking indentation, we should check where that normal
piece of code starts, not where the label starts (there's a separate
INDENTED_LABEL test to check the label itself). Therefore, the
line_stats() function that is used to get indentation level should treat
goto labels like whitespace. The SUSPICIOUS_CODE_INDENT test also needs
to explicitly ignore labels to make sure it doesn't get confused by
them.

Signed-off-by: Julius Werner <jwerner@chromium.org>
---
 scripts/checkpatch.pl | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 624a23c05f5388..6fd16111b52cc6 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1396,8 +1396,12 @@ sub copy_spacing {
 sub line_stats {
 	my ($line) = @_;
 
-	# Drop the diff line leader and expand tabs
+	# Drop the diff line leader
 	$line =~ s/^.//;
+
+	# Treat labels like whitespace when counting indentation
+	$line =~ s/^( ?$Ident:)/" " x length($1)/e;
+
 	$line = expand_tabs($line);
 
 	# Pick the indent from the front of the line.
@@ -4195,6 +4199,9 @@ sub process {
 			# Remove any comments
 			$s_next =~ s/$;//g;
 
+			# Remove any leading labels
+			$s_next =~ s/\n( ?$Ident:)/"\n" . " " x length($1)/eg;
+
 			# Skip this check for in case next statement starts with 'else'
 			if ($s_next !~ /\belse\b/) {
 
-- 
2.29.2