Re: [PATCH] checkpatch: fix a number of COMPLEX_MACRO false positives

[Vladimir Zapolskiy]

On 30.10.2015 00:46, Joe Perches wrote:
> On Thu, 2015-10-29 at 23:36 +0200, Vladimir Zapolskiy wrote:
>> A simple search over the kernel souce displays a number of correctly
>> defined multiline macro, which generally are used as an array element
>> initializer:
>>
>> % find ../linux -type f | xargs grep -B1 -H '^[:space]*\[.*\\$'
>>
>> However checkpatch.pl unexpectedly complains about all these macro
>> definitions:
>>
>> % ./scripts/checkpatch.pl --types COMPLEX_MACRO -f include/linux/perf/arm_pmu.h
>>
>> ERROR: Macros with complex values should be enclosed in parentheses
>> +#define PERF_MAP_ALL_UNSUPPORTED					\
>> +	 [0 ... PERF_COUNT_HW_MAX - 1] = HW_OP_UNSUPPORTED
>>
>> The change intends to fix this type of false positives by flattening
>> only array members and skipping array element designators.
>>
>> Signed-off-by: Vladimir Zapolskiy <vz@xxxxxxxxx>
>> ---
>>  scripts/checkpatch.pl | 5 +++--
>>  1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
>> index f2a1131..3882893 100755
>> --- a/scripts/checkpatch.pl
>> +++ b/scripts/checkpatch.pl
>> @@ -4526,7 +4526,7 @@ sub process {
>>  			# Flatten any parentheses and braces
>>  			while ($dstat =~ s/\([^\(\)]*\)/1/ ||
>>  			       $dstat =~ s/\{[^\{\}]*\}/1/ ||
>> -			       $dstat =~ s/\[[^\[\]]*\]/1/)
>> +			       $dstat =~ s/.\[[^\[\]]*\]/1/)
> 
> Perhaps the . before the [ might be a bit broad.

At this point preceding spaces and parentheses are removed, probably any
alphanumeric symbol should fit here.

OTOH I believe in correct C code here before \[ symbol you may find only
an alphanumeric symbol or ^, so I don't expect any false negatives, if .
is used above.

> I'm not sure there's a great way to handle this.
> 
> Andy?
> 
>>  			{
>>  			}
>>  
>> @@ -4546,7 +4546,8 @@ sub process {
>>  				union|
>>  				struct|
>>  				\.$Ident\s*=\s*|
>> -				^\"|\"$
>> +				^\"|\"$|
>> +				^\[
>>  			}x;
>>  			#print "REST<$rest> dstat<$dstat> ctx<$ctx>\n";
>>  			if ($dstat ne '' &&
> 
> 
> 

--
With best wishes,
Vladimir
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