linux-kernel - Re: [PATCH] bluetooth: btwilink: remove unnecessary static in bt_ti

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Date:   Thu, 20 Jul 2017 11:20:46 +0200
From:   Marcel Holtmann <marcel@...tmann.org>
To:     "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Cc:     "Gustavo F. Padovan" <gustavo@...ovan.org>,
        Johan Hedberg <johan.hedberg@...il.com>,
        "open list:BLUETOOTH DRIVERS" <linux-bluetooth@...r.kernel.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] bluetooth: btwilink: remove unnecessary static in
 bt_ti_probe()

Hi Gustavo,

> Remove unnecessary static on local variable hst.
> Such variable is initialized before being used,
> on every execution path throughout the function.
> The static has no benefit and, removing it reduces
> the object file size.
> 
> This issue was detected using Coccinelle and the
> following semantic patch:
> 
> @bad exists@
> position p;
> identifier x;
> type T;
> @@
> 
> static T x@p;
> ...
> x = <+...x...+>
> 
> @@
> identifier x;
> expression e;
> type T;
> position p != bad.p;
> @@
> 
> -static
> T x@p;
> ... when != x
>     when strict
> ?x = e;
> 
> In the following log you can see the difference in the object file size.
> This log is the output of the size command, before and after the code
> change:
> 
> before:
>   text    data     bss     dec     hex filename
>   4029    2528     128    6685    1a1d drivers/bluetooth/btwilink.o
> 
> after:
>   text    data     bss     dec     hex filename
>   4007    2472      64    6543    198f drivers/bluetooth/btwilink.o
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@...eddedor.com>
> ---
> drivers/bluetooth/btwilink.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel