From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755944AbYISGyi (ORCPT ); Fri, 19 Sep 2008 02:54:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750893AbYISGya (ORCPT ); Fri, 19 Sep 2008 02:54:30 -0400 Received: from fg-out-1718.google.com ([72.14.220.158]:51634 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840AbYISGy3 (ORCPT ); Fri, 19 Sep 2008 02:54:29 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=TzkdQ6OzGqKAZhvFmdquESG+rWinDjN3cqYnaJ8to1qnJvBDYrbBQ3WrjafBebC4k2 MeUqgZ7T0VTibcrkyt/u5te2ORSpKzNwbjBvREcSif9r6Iwhf+krgTWkE5mjdiP6bT8b S0/RNaXDIKyvBUpu8/OfHZf38zzkmg6hpB4IY= Date: Fri, 19 Sep 2008 10:54:26 +0400 From: Cyrill Gorcunov To: Eric Miao Cc: Alexey Dobriyan , Ben Dooks , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.arm.linux.org.uk Subject: Re: kernel.h: add ARRAY_AND_SIZE() macro to complement ARRAY_SIZE(). Message-ID: <20080919065426.GA7222@lenovo> References: <20080918132447.516309749@fluff.org.uk> <20080918150624.GA3421@x200.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Eric Miao - Fri, Sep 19, 2008 at 02:38:21AM +0800] | On Thu, Sep 18, 2008 at 11:06 PM, Alexey Dobriyan wrote: | > On Thu, Sep 18, 2008 at 02:24:47PM +0100, Ben Dooks wrote: | >> Move the ARRAY_AND_SIZE() macro from arch/arm/mach-pxa/generic.h | >> to a more useful position in include/linux/kernel.h. This macro | >> is very useful to registration functions that take an array and | >> the number of array elements in it as consecutive arguments. | >> | >> The macro also should ensure that mistakes where the wrong array | >> is used to the ARRAY_SIZE() macro is passed. It also makes it | >> easier to avoid wrapping registration function arguments. | > | >> --- linux-2.6.27-rc6-quilt4.orig/include/linux/kernel.h | >> +++ linux-2.6.27-rc6-quilt4/include/linux/kernel.h | >> @@ -43,6 +43,7 @@ extern const char linux_proc_banner[]; | >> #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) | >> | >> #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) | >> +#define ARRAY_AND_SIZE(arr) (arr), ARRAY_SIZE(arr) | > | > Just like ARRAY_SIZE, it is misnamed. | > | | Any hint about the correct spelling? | | > And it isn't obvious to what it expands. Hopefully arm people will | > remove it. :-) | | This is handy to use, saving several key strokes and making the line | shorter. If it's not obvious to what it expands, there must be some | fix for it? | well, it seems it's not that good to use ARRAY_AND_SIZE at all. Yes it's short but quite frankly - hiding number of args is not that good. example static void ssp_send_cmd(uint32_t *cmd, int num); called as ssp_send_cmd(ARRAY_AND_SIZE(lcd_panel_on)); thanks it's not that spreaded across kernel. Someday it could lead to ARRAY_AND_SIZE_CHECK_IF_EXIST_AND_PANIC :) I hope you agree with me. - Cyrill -