From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BBE0C25B4E for ; Tue, 24 Jan 2023 08:11:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232656AbjAXILy (ORCPT ); Tue, 24 Jan 2023 03:11:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231749AbjAXILx (ORCPT ); Tue, 24 Jan 2023 03:11:53 -0500 Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCD693EFDB; Tue, 24 Jan 2023 00:11:26 -0800 (PST) Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost.zedat.fu-berlin.de (Exim 4.95) with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (envelope-from ) id 1pKEOc-002VKM-MY; Tue, 24 Jan 2023 09:11:10 +0100 Received: from dynamic-078-055-147-119.78.55.pool.telefonica.de ([78.55.147.119] helo=[192.168.1.11]) by inpost2.zedat.fu-berlin.de (Exim 4.95) with esmtpsa (TLS1.3) tls TLS_AES_128_GCM_SHA256 (envelope-from ) id 1pKEOc-001g7K-GG; Tue, 24 Jan 2023 09:11:10 +0100 Message-ID: <17abaf48-9ef3-72e2-010a-7e707d253fa8@physik.fu-berlin.de> Date: Tue, 24 Jan 2023 09:11:09 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH v5 1/1] arch/sh: avoid spurious sizeof-pointer-div warning Content-Language: en-US To: Michael Karcher , linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org, Segher Boessenkool , Rich Felker , Yoshinori Sato References: <9d3bd61a-725c-db40-b3bd-78460bc7e719@mkarcher.dialup.fu-berlin.de> From: John Paul Adrian Glaubitz In-Reply-To: <9d3bd61a-725c-db40-b3bd-78460bc7e719@mkarcher.dialup.fu-berlin.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Original-Sender: glaubitz@physik.fu-berlin.de X-Originating-IP: 78.55.147.119 Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org Hello! On 1/23/23 21:05, Michael Karcher wrote: > Gcc warns about the pattern sizeof(void*)/sizeof(void), as it looks like > the abuse of a pattern to calculate the array size. This pattern appears > in the unevaluated part of the ternary operator in _INTC_ARRAY if the > parameter is NULL. > > The replacement uses an alternate approach to return 0 in case of NULL > which does not generate the pattern sizeof(void*)/sizeof(void), but still > emits the warning if _INTC_ARRAY is called with a nonarray parameter. > > This patch is required for successful compilation with -Werror enabled. > > The idea to use _Generic for type distinction is taken from Comment #7 > inhttps://gcc.gnu.org/bugzilla/show_bug.cgi?id=108483 by Jakub Jelinek > > Signed-off-by: Michael Karcher > --- > History: > v5: > - Cleanly generated the patch > v4: > - Put the case distinction into the numerator instead of the denominator > - Refactor the case disctinction into a second macro > v3: > - I had a stern discussion with Thunderbird about not mangling the > space characters in my email, and I hope spaces get sent as standard > spaces now > v2: > - improve title and remove mostly redundant first sentence of the > description > - adjust formatting of the _Generic construction > > diff --git a/include/linux/sh_intc.h b/include/linux/sh_intc.h > index c255273b0281..37ad81058d6a 100644 > --- a/include/linux/sh_intc.h > +++ b/include/linux/sh_intc.h > @@ -97,7 +97,10 @@ struct intc_hw_desc { > unsigned int nr_subgroups; > }; > > -#define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(*a) > +#define _INTC_SIZEOF_OR_ZERO(a) (_Generic(a, \ > + typeof(NULL): 0, \ > + default: sizeof(a))) > +#define _INTC_ARRAY(a) a, _INTC_SIZEOF_OR_ZERO(a)/sizeof(*a) > > #define INTC_HW_DESC(vectors, groups, mask_regs, \ > prio_regs, sense_regs, ack_regs) \ Can anyone suggest which tree to pick this up through until we have established a new linux-sh tree? Shall this go through Andrew's tree? Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913