linux-kernel - Re: [Cocci] [PATCH] crypto: cavium: zip: Remove unnecessary parentheses

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Date:   Sat, 31 Mar 2018 14:18:44 +0530
From:   Varsha Rao <rvarsha016@...il.com>
To:     Julia Lawall <julia.lawall@...6.fr>
Cc:     Joe Perches <joe@...ches.com>, linux-crypto@...r.kernel.org,
        linux-kernel@...r.kernel.org, cocci <cocci@...teme.lip6.fr>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>
Subject: Re: [Cocci] [PATCH] crypto: cavium: zip: Remove unnecessary parentheses

On Sat, Mar 31, 2018 at 11:48 AM, Julia Lawall  wrote:
> On Thu, 29 Mar 2018, Varsha Rao wrote:
>
>> On Wed, Mar 28, 2018 at 11:41 PM, Joe Perches wrote:
>> >
>> > On Wed, 2018-03-28 at 23:27, Varsha Rao wrote:
>> > > This patch fixes the clang warning of extraneous parentheses, with the
>> > > following coccinelle script.
>> > >
>> > > @@
>> > > identifier i;
>> > > constant c;
>> > > @@
>> > > (
>> > > -((i == c))
>> > > +i == c
>> > > >
>> > >
>> > > -((i <= c))
>> > > +i <= c
>> >
>> > Why just the "==" and "<=" cases?
>> > Why not "<", ">" and ">=" too?
>> >
>> > Why not expression instead of constant?
>>
>> Initially I had the other cases too and used expression instead of
>> constant. But the results included only "==" and "<=" cases with
>> constant. Along with one false positive case.
>>
>> --- a/drivers/crypto/cavium/zip/zip_main.c
>> +++ b/drivers/crypto/cavium/zip/zip_main.c
>> @@ -99,7 +99,7 @@ static struct zip_device *zip_alloc_devi
>>   */
>>  struct zip_device *zip_get_device(int node)
>>  {
>> -    if ((node < MAX_ZIP_DEVICES) && (node >= 0))
>> +    if (node < MAX_ZIP_DEVICES && node >= 0)
>
> Why is it a false positive?

The parentheses around multiple expressions in if statement is not
considered extra, right?

Thanks,
Varsha

> julia
>
>>          return zip_dev[node];
>>
>>      zip_err("ZIP device not found for node id %d\n", node);
>>
>> I checked if there was any case of extra parentheses around relational
>> operators left, but there were none. Hence, in the script I included
>> only the cases present in the result.
>>
>> Thanks,
>> Varsha
>> _______________________________________________
>> Cocci mailing list
>> Cocci@...teme.lip6.fr
>> https://systeme.lip6.fr/mailman/listinfo/cocci
>>

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