From mboxrd@z Thu Jan  1 00:00:00 1970
From: der.herr@hofr.at (Nicholas Mc Guire)
Date: Thu, 30 Mar 2017 16:05:51 +0000
Subject: &array[0] vs array
In-Reply-To: <eed8bdcf-bb74-cb0d-aa85-3f705201c70d@mrbrklyn.com>
References: <20170330003044.GI25014@eros>
	<eed8bdcf-bb74-cb0d-aa85-3f705201c70d@mrbrklyn.com>
Message-ID: <20170330160551.GA32725@osadl.at>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

On Thu, Mar 30, 2017 at 09:04:35AM -0400, Ruben Safir wrote:
> On 03/29/2017 08:30 PM, Tobin C. Harding wrote:
> > Does the kernel community have a preference when using the address of
> > the first element of an an array?
> > 
> > 1. addr = &array[0]
> > 2. addr = array;
> > 
> > $ grep '\&.*\[0\]' | wc -l
> > 10077
> > 
> > style (1) is clearly used, I was not able to grep for instances where
> > style (2) is used.
> 
> maybe there is a another reason why 2 is not used.
>
the second form is used - just not quite as often  
with the below quick (and probably incomplete) coccinelle script you 
can find a few hundred occurences of the second form in linux-next 

<snip>
virtual report

@v2@
identifier array,addr;
type T;
position p;
@@

(
* T array[];
|
* T array[] = ...;
)
 ...
* addr = array at p
 
@script:python@
p << v2.p;
@@
print "%s:%s" % (p[0].file,p[0].line)
<snip>

If its really obvious that its an array that you are manipulating
maybe the second version is fine - if its not so obvious the
first version makes it clear - and as readability is a key issue
for any complex code I suspect that readability explains the preference.

thx!
hofrat