Commit c34c09a8 authored Jan 23, 2014 by Joe Perches Committed by Linus Torvalds Jan 23, 2014

checkpatch: attempt to find missing switch/case break;



switch case statements missing a break statement are an unfortunately
common error.

e.g.:
  commit 4a2c94c9 ("HID: kye: Add report fixup for Genius Manticore Keyboard")

case blocks should end in a break/return/goto/continue.

If a fall-through is used, it should have a comment showing that it is
intentional.  Ideally that comment should be something like:
"/* fall-through */"

Add a test to look for missing break statements.

This looks only at the context lines before an inserted case so it's
possible to have false positives when the context contains a close brace
and the break is before the brace and not part of the patch context.

Looking at recent patches, this is a pretty rare occurrence.  The normal
kernel style uses a break as the last line of the previous block.

Signed-off-by: Joe Perches <joe@perche.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7e4915e7

scripts/checkpatch.pl

+25 −0

Original line number	Diff line number	Diff line
		@@ -4128,6 +4128,31 @@ sub process {
		}
		}

		# check for case / default statements not preceeded by break/fallthrough/switch
		if ($line =~ /^.\s(?:case\s+(?:$Ident\|$Constant)\s\|default):/) {
		my $has_break = 0;
		my $has_statement = 0;
		my $count = 0;
		my $prevline = $linenr;
		while ($prevline > 1 && $count < 3 && !$has_break) {
		$prevline--;
		my $rline = $rawlines[$prevline - 1];
		my $fline = $lines[$prevline - 1];
		last if ($fline =~ /^\@\@/);
		next if ($fline =~ /^\-/);
		next if ($fline =~ /^.(?:\s(?:case\s+(?:$Ident\|$Constant)[\s$;]\|default):[\s$;])$/);
		$has_break = 1 if ($rline =~ /fall[\s_-]*(through\|thru)/i);
		next if ($fline =~ /^.[\s$;]*$/);
		$has_statement = 1;
		$count++;
		$has_break = 1 if ($fline =~ /\bswitch\b\|\b(?:break\s;[\s$;]$\|return\b\|goto\b\|continue\b)/);
		}
		if (!$has_break && $has_statement) {
		WARN("MISSING_BREAK",
		"Possible switch case/default not preceeded by break or fallthrough comment\n" . $herecurr);
		}
		}

		# check for switch/default statements without a break;
		if ($^V && $^V ge 5.10.0 &&
		defined $stat &&

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