From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.7 required=3.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 0CDA21F424 for ; Wed, 9 May 2018 21:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965214AbeEIVnk (ORCPT ); Wed, 9 May 2018 17:43:40 -0400 Received: from mout.gmx.net ([212.227.17.20]:38105 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935325AbeEIVnj (ORCPT ); Wed, 9 May 2018 17:43:39 -0400 Received: from [10.92.140.17] ([167.220.148.17]) by mail.gmx.com (mrgmx101 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MOjMY-1fChO64A8U-0066tI; Wed, 09 May 2018 23:43:33 +0200 Date: Wed, 9 May 2018 17:43:30 -0400 (DST) From: Johannes Schindelin X-X-Sender: virtualbox@gitforwindows.org To: =?UTF-8?Q?Ren=C3=A9_Scharfe?= cc: Git List , Junio C Hamano Subject: Re: [PATCH] fast-export: avoid NULL pointer arithmetic In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21.1 (DEB 209 2017-03-23) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323328-159547254-1525902213=:77" X-Provags-ID: V03:K1:7RDmjw8lIeVVfl1w+4jANJ5G9qrxpAzAJW+KUOr5NjfXTcGe5vu 6Lu6TxWn9+OWutnzt7IOeI2qsHknKjdR1XI2uErqiFJwUCVhinAi6fglZS/ZT8ZCjZUEMt0 mgiTEV4O5g2jVdNNCljkJDpkI08Ww5S3/GN6vxqZ34A9lOOEbyQq/j5uOqNQuZLbJJL4Rj3 SfXVZS1JDcU+H07BE8x0Q== X-UI-Out-Filterresults: notjunk:1;V01:K0:9vU5BnMQr7c=:m3U+MAafSADwqg+4GAxM2P FSfqP0APJBxTdTmLP1216rvVz2KoM1YKo+hFw4t3/U/2tkolvszH88OcgKh4ZZPqBLWsSthab 8HrF0WuZS3ZD2F4xVMtYCn7TjaPbGYN+00hAOorBlrDiyfawl4+82b/tn39SNpFj0yBtWivbv OgU5bsOjOEddTbXPI3UY1uTGLmLjKrvVzJyVj72vN+H3d+ZEQ7xIYkl3CEs9tD9HVB3le+l0f vntYKeqJq8M/JS4ey3gVmMn3LxMNOnXqskm0di7PocAJTavT+JqXXHlwD+GGs6mVUibuArWZM qQEWGFOBLX5XEjk/CvVhAiuEsP9RfkDzr7GGt5iLLLY3B+d/Em7WQFfpMurOwlpOhL1oU1M1f uiZnUxILz/mo6MJYDfF15LG4dfy6eBZnNM4ozw+R3dLnurJKV7E/iPZqp3G0uRPzEp4nMVZPI pU5l+FmItILReSVWHOjtQ+pv3voETzES3ImOLJSuYGJeaSqqkihoEWvi5oV30I/4aLxXxQMGc BH9WS9J7zuwY2ZI6cOE+1wUnw59PT6wzgIbTjOOns50i3jyCbTI9Y2hcWJSv3BzSKQY8RB0LH rYVX5AFWnp3IB159N3gtK5o1WIPEKKS5I98jJWq+Rleh+7zf1+rbB/yH9/NKPqyNmuT8rqmZf w9dT79UB5TTkBnAdY/V3OveRAKhQe0I9FMzravv66sB8NaYwcXgHjQEonjlwe2jKltx5jh+ly ZSha0ofuFdKuhWV/cp/xl6dPcwixXxX4wLmLs4lJEwgJUuHMEK2uZVmw5dGFRoBXRfS1/iP2/ FE+iUXp Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-159547254-1525902213=:77 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Hi Ren=C3=A9, On Wed, 9 May 2018, Ren=C3=A9 Scharfe wrote: > Clang 6 reports the following warning, which is turned into an error in a > DEVELOPER build: >=20 > =09builtin/fast-export.c:162:28: error: performing pointer arithmetic on = a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic] > =09=09return ((uint32_t *)NULL) + mark; > =09=09 ~~~~~~~~~~~~~~~~~~ ^ > =091 error generated. >=20 > The compiler is correct, and the error message speaks for itself. There > is no need for any undefined operation -- just cast mark to void * or > uint32_t after an intermediate cast to uintptr_t. That encodes the > integer value into a pointer and later decodes it as intended. >=20 > While at it remove an outdated comment -- intptr_t has been used since > ffe659f94d (parse-options: make some arguments optional, add callbacks), > committed in October 2007. ACK. Thanks, Dscho --8323328-159547254-1525902213=:77--