>>>>> +# nested likely/unlikely calls >>>>> + if ($line =~ /\b(?:(?:un)?likely)\s*\(\s*!?\s*(IS_ERR(?:_OR_NULL|_VALUE)?|WARN)/) { >>>>> + WARN("LIKELY_MISUSE", … >> \b(?:un)?likely\s* > > This pair of brackets is required to match "unlikely" > and it's optional in order to match "likely". I agree also to this view if you refer to the shortened regular expression here. But I got an other development opinion for an extra pair of non-capturing parentheses at the front (from the version which you suggested). Regards, Markus