From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_NONE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id BB7201F461 for ; Thu, 5 Sep 2019 19:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389301AbfIETjz (ORCPT ); Thu, 5 Sep 2019 15:39:55 -0400 Received: from mout.web.de ([212.227.15.4]:55679 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388174AbfIETjz (ORCPT ); Thu, 5 Sep 2019 15:39:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1567712379; bh=L+TxzkJfMSmzirk7dIn3ie3u1ek2qo/GittT8wkILT0=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=ViWZKZQsFl1gpadf3Y8/p84mPA0j6nUdzOPZ5ypeZlin4uYepwJSzuKJZ67PehLIL 4j2YMhzvRUuXep04O3pth+Ob39djfPtarey7WLtzdcfgL/RPutndbyAJNkxyuIK3/v 7a0qic6ItKRQrl2/VOMjBuVJ6x79Dg4lc3Tb97jY= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from [192.168.178.26] ([79.203.24.71]) by smtp.web.de (mrweb004 [213.165.67.108]) with ESMTPSA (Nemesis) id 0LwU2B-1iDzgi0VQt-018HVo; Thu, 05 Sep 2019 21:39:39 +0200 Subject: Re: [PATCH] Fix maybe-uninitialized warnings found by gcc 9 -flto To: Junio C Hamano Cc: Jeff King , Stephan Beyer , Paul Tan , "brian m. carlson" , Johannes Schindelin , git@vger.kernel.org References: <20190905082459.26816-1-s-beyer@gmx.net> <6c6c4e71-d9e5-1ad4-74db-12c323da42f7@web.de> <20190905175304.GA23663@sigill.intra.peff.net> From: =?UTF-8?Q?Ren=c3=a9_Scharfe?= Message-ID: <8d90d803-8a4b-2656-550d-ccee5156b643@web.de> Date: Thu, 5 Sep 2019 21:39:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:dHAyfVz7p2VNKf/dkYDn6bkkjckI4LapsPpcG2aQh0QI7bz/6cx cdDfwWk5SzT1s+x9HZSCPbtJjBQ/wiEgXREpPf2bpx5KMcKCm+pOaNv5E/7cIeuTS8wW2XK x0fxe82KSoa5whtESBJPWIQWW4gX6PcRK5E/PcnTdZQcpLa1T8slVIDpMBYGvMWeEmDmN8E hyfRzDo+cEWF7w09BpOUA== X-UI-Out-Filterresults: notjunk:1;V03:K0:XLSnAwJJ2UI=:SCOYiiGcHahf5/WysNSaL3 SOObtYIbA9usGE6c4JTrRKQ1Q3R6pJLWLt/dp+BWtct4jnrS1FoeE8/CkAViL91WLq5KgNHlq FWupAAFC4JK3GhUiBfUiT4fW/NVdoqKQhEewrl6XG9AKy1WrGkGeO4yy1Q+Z3iiMG1zsbEyKG 0t3jxOr4v0X3B5eRZqfhVShCIVsT9zV4cXJQlXpvKPrxq4MNqfRV3T6RcxBStGz2dPBiYekK4 zvdMkGrqrhqkc6/rWKBcApURpLnq0r3vWVwI97DI3TgTE2l1zQ0Dm52nNMoVlmLiIO00cF4xa iKtuF+KgKO7s/cyeKxiYT+lcdvUZtNILeLTBjji8z7HWzfCw3sffZRACB0lEyav+d1IHORFSx ORuaevfZFe6EvtAZzKnq8GPT115izTQISSitLGE5ab0TrQ3y03ivH81NgFdicKLnHt29dzkrQ g8EUEuaw7LbK0c858BUbiFMpqoC9UhHNJjlH8tn1w95XcN6AX3YzLUwWU49wjZaACnkewFxp7 rB69cAJ/oCENgfHHFs6CGYdYBmt3rHH+yRG6ubHYsHU09ULpzCm62qu9OhouTM5/urjwHSStC dpx2h3u8hJdEkHP7FM40V/z/yRg9k4xqXs7gUSnHevpMdZJKp2hH69cTL0SidPhXzXN5TQgy+ SdGQqpQen9cQGo/mlEfhYl6seTNJluUepbchvnYdN1H16Ep3eyYpcOcT1Vd00tfLInURFYwzR jKbd5wdbzea/pj2lJe2cEy3Ev8km6Q8+dw/H2IMfk7yUqIHCAkLQwvK7svkdrnpq1gkrjxGry zRoTTGmBZZIo7iNGoNGAAr+8NzuhI3auoyyc12BbKVCkLhq04OJBvhSxoSo21vGROLDYP9NsY KyxWUvr/VMXrSZru0RwVKZOH/EW/XwE5jD/DG4yCYiB0eSXWVn3IwqCSTxCn2JgIC7sp8PUPK dFOlAudjb1FYq/286jMWTn4mqDV6Igh1xE6xIIo7tJg/yuVAr2XkL5xMxAYP/0b4MtVnhDVcq OtYFgQOZ+QP+GSzMMzyXcUbkounOx+JA2T5b/S/TN/9gd61uNFJb/3JFKo4d5EXmk5Q7UkxDs soRRvmkKP2YceUf+PalEF1n45IkdQt33MFysZgqDoD6475faQ4OoSmdt7YYbKrb4dvBMK4vQd xtY2nLfzXaPTUcl6yiEFTFTbDlV2YRqQn4fD1juog5Lz2il5ekqHUVmwSVgZDr/zLLKl8= Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Am 05.09.19 um 21:25 schrieb Junio C Hamano: > Ren=C3=A9 Scharfe writes: > >> Am 05.09.19 um 19:53 schrieb Jeff King: >>>>> int cmd__read_cache(int argc, const char **argv) >>>>> { >>>>> - int i, cnt =3D 1, namelen; >>>>> + int i, cnt =3D 1, namelen =3D 0; >>> >>> I actually saw this one the other day, because it triggered for me whe= n >>> compiling with SANITIZE=3Daddress. AFAICT it's a false positive. "name= " is >>> always NULL unless skip_prefix() returns true, in which case we always >>> set "namelen". And we only look at "namelen" if "name" is non-NULL. >>> >>> This one doesn't even require LTO, because skip_prefix() is an inline >>> function. I'm not sure why the compiler gets confused here. >> >> Yes, that's curious. >> >>> I don't mind >>> initializing namelen to 0 to silence it, though (we already set name t= o >>> NULL, so this would just match). >> >> Pushing the strlen() call into the loop and getting rid of namelen shou= ld >> work as well -- and I'd be surprised if this had a measurable performan= ce >> impact. > > Yeah, we are making strlen() call on a constant "name" in a loop > over argv[]. I do not think it matters in this case, either. The loop count is either 1 or argv[1] interpreted as a number, i.e. it cou= ld be very high. Its body consists of an index load and writing a number to = a file, though -- a strlen() call on the name of that file should go unnotic= ed amid that activity. (I didn't measure it, though.) Ren=C3=A9