From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zimbra.cs.ucla.edu (zimbra.cs.ucla.edu [131.179.128.68]) by sourceware.org (Postfix) with ESMTPS id F14943858401 for ; Wed, 27 Oct 2021 09:35:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org F14943858401 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=cs.ucla.edu Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=cs.ucla.edu Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 1BD621600C5; Wed, 27 Oct 2021 02:35:36 -0700 (PDT) Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 3rE3N50_EH8H; Wed, 27 Oct 2021 02:35:35 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 767C51600D3; Wed, 27 Oct 2021 02:35:35 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id M8sZnmKWF4-k; Wed, 27 Oct 2021 02:35:35 -0700 (PDT) Received: from [192.168.1.9] (cpe-172-91-119-151.socal.res.rr.com [172.91.119.151]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 52EE31600C5; Wed, 27 Oct 2021 02:35:35 -0700 (PDT) Message-ID: Date: Wed, 27 Oct 2021 02:35:34 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.1.2 Subject: Re: [PATCH] regex: Unnest nested functions in regcomp.c Content-Language: en-US To: Fangrui Song References: <20211027052959.2549214-1-maskray@google.com> Cc: libc-alpha@sourceware.org From: Paul Eggert Organization: UCLA Computer Science Department In-Reply-To: <20211027052959.2549214-1-maskray@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, NICE_REPLY_A, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Oct 2021 09:35:38 -0000 On 10/26/21 22:29, Fangrui Song wrote: > collseqwc, table_size, symb_table, extra are now initialized to appease > GCC -Werror=maybe-uninitialized false positive. Are the diagnostics really false positives? As I understand it, the modified code would have undefined behavior if these variables were not initialized. Can you comment on the efficiency of the modified code compared to the original, when compiled with recent GCC?