[PATCH] checkpatch: skip macros when finding missing switch/case break

[PATCH] checkpatch: skip macros when finding missing switch/case break

[Cambda Zhu]

The checkpatch.pl only searches 3 previous lines when finding missing
switch/case break, and macros are treated as normal statements. If the
cases are surrounded with CONFIG, checkpatch.pl may report false
warnings. For example:

\+#if xxx
\+	case xxx: {
\+		...
\+		break/return/...;
\+	}
\+#endif
\+#if xxx
\+	case xxx:
\+		...
\+#endif

This patch skips lines starting with whitespaces and #, so the counter
of previous statements won't increase in these cases.

Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
---
 scripts/checkpatch.pl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4c820607540b..2c0a51ac82a7 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6503,6 +6503,7 @@ sub process {
 				next if ($fline =~ /^.(?:\s*(?:case\s+(?:$Ident|$Constant)[\s$;]*|default):[\s$;]*)*$/);
 				$has_break = 1 if ($rline =~ /fall[\s_-]*(through|thru)/i);
 				next if ($fline =~ /^.[\s$;]*$/);
+				next if ($fline =~ /^.\s*#/);
 				$has_statement = 1;
 				$count++;
 				$has_break = 1 if ($fline =~ /\bswitch\b|\b(?:break\s*;[\s$;]*$|exit\s*\(\b|return\b|goto\b|continue\b)/);
-- 
2.16.6

Re: [PATCH] checkpatch: skip macros when finding missing switch/case break

[Joe Perches]

On Wed, 2020-07-29 at 20:59 +0800, Cambda Zhu wrote:
> The checkpatch.pl only searches 3 previous lines when finding missing
> switch/case break, and macros are treated as normal statements. If the
> cases are surrounded with CONFIG, checkpatch.pl may report false
> warnings. For example:

Likely this test should be removed altogether as
it's never really worked well and now compilers
find this and emit warnings.

Re: [PATCH] checkpatch: skip macros when finding missing switch/case break

[Cambda Zhu]

I agree with you. Actually there are some false warnings not mentioned in my patch, such as:

case xxx: {
   if () {
       return;
   } else {
           if () {
               return;
           } else {
               return;
           }
   }
}
case xxx:
   ...

Since compiler can do this now, I think this test should be removed.

Regards,
Cambda

> 在 2020年8月1日，02:05，Joe Perches <joe@perches.com> 写道：
> 
> On Wed, 2020-07-29 at 20:59 +0800, Cambda Zhu wrote:
>> The checkpatch.pl only searches 3 previous lines when finding missing
>> switch/case break, and macros are treated as normal statements. If the
>> cases are surrounded with CONFIG, checkpatch.pl may report false
>> warnings. For example:
> 
> Likely this test should be removed altogether as
> it's never really worked well and now compilers
> find this and emit warnings.