Re: [PATCH v3 01/11] checkpatch: check for nested (un)?likely() calls

[Denis Efremov <efremov@xxxxxxxxx>]

On 31.08.2019 12:15, Markus Elfring wrote:
>> +# nested likely/unlikely calls
>> +        if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) {
>> +            WARN("LIKELY_MISUSE",
> 
> How do you think about to use the specification “(?:IS_ERR(?:_(?:OR_NULL|VALUE))?|WARN)”
> in this regular expression?

Hmm, 
(?:   <- Catch group is required here, since it is used in diagnostic message,
         see $1
   IS_ERR
   (?:_ <- Another atomic group just to show that '_' is a common prefix?
           I'm not sure about this. Usually, Perl interpreter is very good at optimizing such things.
           You could see this optimization if you run perl with -Mre=debug.
     (?:OR_NULL|VALUE))?|WARN)

Regards,
Denis