&array[0] vs array
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. thanks, Tobin.
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. -- So many immigrant groups have swept through our town that Brooklyn, like Atlantis, reaches mythological proportions in the mind of the world - RI Safir 1998 http://www.mrbrklyn.com DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002 http://www.nylxs.com - Leadership Development in Free Software http://www2.mrbrklyn.com/resources - Unpublished Archive http://www.coinhangout.com - coins! http://www.brooklyn-living.com Being so tracked is for FARM ANIMALS and and extermination camps, but incompatible with living as a free human being. -RI Safir 2013
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@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
On Thu, Mar 30, 2017 at 04:05:51PM +0000, Nicholas Mc Guire wrote:
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@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.
Got it, readability over brevity. thanks, Tobin.
participants (3)
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Nicholas Mc Guire -
Ruben Safir -
Tobin C. Harding