Message ID | 8dc791f9-3b44-e81d-6877-c21b9180c48a@mkarcher.dialup.fu-berlin.de |
---|---|
State | New |
Headers |
Return-Path: <linux-kernel-owner@vger.kernel.org> Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp1298373wrn; Sun, 22 Jan 2023 12:53:17 -0800 (PST) X-Google-Smtp-Source: AMrXdXsrFZsiidZedC3qO+FSX8bjnxWVHl7O9hYxmHw91F/7s5LXfHzrQpimYAQxa0lAlpd9mHI0 X-Received: by 2002:a05:6a20:7d9c:b0:ad:2abb:5a5e with SMTP id v28-20020a056a207d9c00b000ad2abb5a5emr58448625pzj.61.1674420797040; Sun, 22 Jan 2023 12:53:17 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674420797; cv=none; d=google.com; s=arc-20160816; b=HPX6PiuzX7n4b6UECj9NLHCT/AQm/lptU3AuHfIyR1b1JAMsihVIncoDfETsjmTHaw zxT6MsgHRiTc9V8cToBcsLcfKb84I0/VAnv6UctOBhbo73ggMWfKkNcheuu4Hl7DyCc/ lD1kxLIx2curRo9KXdL0PbJyaIwaVKSNjq6kA5K7aE4NKTOLUk8SFayWv5qT+HITMBAL HPdrlw7xnVxshqYvayBXAWq3mfJfhbP1kMNyH/+GWibQgdj+i5PV79Yecb7TyIZmG4bt MYvivQSP+khHJ7PoWqocgAFAzFqN0Cpdw5IjQ6jTeDfcj33QZOguKgk9Q/7OXcMGpV4e 9oIw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:to:subject:from :user-agent:mime-version:date:message-id; bh=PsgqtqUwDhDOfryp5q1HTVd96GkV+qmF10cY2b3x2J8=; b=a6T9hYfhmdUfLJ06syWhwA3AJcE3S8VKNSLoDoRbnbwBLRY3FqqstiKwwB18b1TTA2 egvSQ1B4Tj77dKUfZ65NMImp3C2i8jVhDroEW4498ju9ERpINNSnrq8ASp809v9XJK0Q 3BtGF5tl3S1hHC2Z9V6To/eY9KAot8uRJahFaEudYD9jG/YGVNA5aFQFmj8d+VspURir gx/OzWvUymMqXIEjPSjIDeA63YwACE255IPUAY0cnX5rnV6W4nngf1m3eznkQgvobH7J nosE4uufJL9JxRotoRQsMv0bwp0WMyAk6irTCa7+f2ywep81Lefv4MEcj0CmWPM0JgiT hJoQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id k198-20020a633dcf000000b0049b36d5a275si51773026pga.400.2023.01.22.12.53.05; Sun, 22 Jan 2023 12:53:17 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230114AbjAVUvq (ORCPT <rfc822;forouhar.linux@gmail.com> + 99 others); Sun, 22 Jan 2023 15:51:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229566AbjAVUvp (ORCPT <rfc822;linux-kernel@vger.kernel.org>); Sun, 22 Jan 2023 15:51:45 -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 9DF9F1CF4B; Sun, 22 Jan 2023 12:51:44 -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 <mkarcher@zedat.fu-berlin.de>) id 1pJhJU-000iCf-El; Sun, 22 Jan 2023 21:51:40 +0100 Received: from pd9f631ca.dip0.t-ipconnect.de ([217.246.49.202] helo=[192.168.144.87]) by inpost2.zedat.fu-berlin.de (Exim 4.95) with esmtpsa (TLS1.3) tls TLS_AES_128_GCM_SHA256 (envelope-from <kernel@mkarcher.dialup.fu-berlin.de>) id 1pJhJU-000mJx-8h; Sun, 22 Jan 2023 21:51:40 +0100 Message-ID: <8dc791f9-3b44-e81d-6877-c21b9180c48a@mkarcher.dialup.fu-berlin.de> Date: Sun, 22 Jan 2023 21:51:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 From: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de> Subject: [PATCH v3 1/1] arch/sh: avoid spurious sizeof-pointer-div warning To: linux-kernel@vger.kernel.org, linux-sh@vger.kernel.org, Segher Boessenkool <segher@kernel.crashing.org>, Rich Felker <dalias@libc.org>, Yoshinori Sato <ysato@users.sourceforge.jp>, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Original-Sender: kernel@mkarcher.dialup.fu-berlin.de X-Originating-IP: 217.246.49.202 X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: <linux-kernel.vger.kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1755757461843157548?= X-GMAIL-MSGID: =?utf-8?q?1755757461843157548?= |
Series |
[v3,1/1] arch/sh: avoid spurious sizeof-pointer-div warning
|
|
Commit Message
Michael Karcher
Jan. 22, 2023, 8:51 p.m. UTC
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
in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108483 by Jakub Jelinek
Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de>
---
History:
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
Comments
On 1/22/23 12:51, 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 > in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108483 by Jakub Jelinek > > Signed-off-by: Michael Karcher <kernel@mkarcher.dialup.fu-berlin.de> > --- > History: > 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 Looks good now. Thanks. Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested > 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..98d1da0d8e36 100644 > --- a/include/linux/sh_intc.h > +++ b/include/linux/sh_intc.h > @@ -97,7 +97,9 @@ struct intc_hw_desc { > unsigned int nr_subgroups; > }; > > -#define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(*a) > +#define _INTC_ARRAY(a) a, sizeof(a) / (_Generic(a, \ > + typeof(NULL): (size_t)-1, \ > + default: sizeof(*a))) > > #define INTC_HW_DESC(vectors, groups, mask_regs, \ > prio_regs, sense_regs, ack_regs) \ > >
diff --git a/include/linux/sh_intc.h b/include/linux/sh_intc.h index c255273b0281..98d1da0d8e36 100644 --- a/include/linux/sh_intc.h +++ b/include/linux/sh_intc.h @@ -97,7 +97,9 @@ struct intc_hw_desc { unsigned int nr_subgroups; }; -#define _INTC_ARRAY(a) a, __same_type(a, NULL) ? 0 : sizeof(a)/sizeof(*a) +#define _INTC_ARRAY(a) a, sizeof(a) / (_Generic(a, \ + typeof(NULL): (size_t)-1, \ + default: sizeof(*a))) #define INTC_HW_DESC(vectors, groups, mask_regs, \ prio_regs, sense_regs, ack_regs) \