From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by sourceware.org (Postfix) with ESMTPS id 476E4385842E for ; Thu, 6 Apr 2023 21:29:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 476E4385842E Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-x330.google.com with SMTP id he13so3617393wmb.2 for ; Thu, 06 Apr 2023 14:29:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680816589; x=1683408589; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :sender:from:to:cc:subject:date:message-id:reply-to; bh=KbXUvesbDPhFbnDx7UfV9XKTTiXMhv4byF3f1IFG6yo=; b=mxyxCJh4bMDuHoKphNzwwjoaodgUHfLWhOzZj3X6ZPvANcWiDwk/spHyu//nfBEkX+ uMGLryhAbBmB8B6vRZliG9O89uC8Mv+v06+HzzCv+UVUj7JFG6gsFBo28NoKdDvVv0mL qmmauWdwA/7edFN3XM2pgd6r2OcmgYJzyAs4F49unbEExDvWOh8Zpk7hY29Ut5MnK3FZ 4Nh8jg0TEY2fl+g7IXQsGl5YfsNd2vRmUZ30Ibv/rNPxM82tTDChIJsHea5h4KWxAEDG Fnagy6WJc14zdXyDWjk6rW/w7lC2FoBqVmig2CZhXhR1JH0hG8U39C9Ybpe6GE2h47Ug zbZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680816589; x=1683408589; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :sender:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=KbXUvesbDPhFbnDx7UfV9XKTTiXMhv4byF3f1IFG6yo=; b=6Na4kDrF1p2I+3OU8EIQWmoIAOBR7RmMhk3mZsts6X/jTz+7aXc8iQERIy21A3UmD4 6NBBXV+r8cKwRFMQmBJlf4ESTZwMd60ahIA7rU6KFUHFUbMAp1lmmXYnbNazVxopos3J H9e+YpQfjZBPtYNCwXT+ayIs+ZelHZ0jrNzFDkv+LCJwhEs5k6tlMN5lX7ufquMa3f4P VOzTpTEEqxkv7rOhisn9DF80m4umLmoaRnMVxXD1KXYoQf6DEUciUdmsZek1SsSeONw1 rWYdrrGQnhGGr+6J4JxYSRxTTDb7FLpJuQgMnRufwkL/mtthTITwE8iG+CgneZHN1BBO JrYA== X-Gm-Message-State: AAQBX9f7p4gs5qkCN+ul0D/KcI4Cm40+ipUCQOyGBwj7n/ZRpoTzDRh8 KXoP3/i8nkRd4EUQ8lJGYnw= X-Google-Smtp-Source: AKy350Yk/RdJ4xWwyxntNuKjtiJGSQ/Vq9dNKgqypyyO1m6kw54W8oFxpGAxWjHDE3EouRKX4nc40A== X-Received: by 2002:a7b:c442:0:b0:3ee:7d95:a39f with SMTP id l2-20020a7bc442000000b003ee7d95a39fmr7710907wmi.33.1680816588995; Thu, 06 Apr 2023 14:29:48 -0700 (PDT) Received: from [192.168.0.160] ([170.253.51.134]) by smtp.gmail.com with ESMTPSA id v7-20020a05600c214700b003eb966d39desm2661553wml.2.2023.04.06.14.29.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Apr 2023 14:29:48 -0700 (PDT) Sender: Alejandro Colomar Message-ID: <354b6c68-c692-25f0-089d-b7d7aad19b63@gmail.com> Date: Thu, 6 Apr 2023 23:29:47 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH 1/2] Implement strlcpy and strlcat [BZ #178] Content-Language: en-US To: Siddhesh Poyarekar , Florian Weimer , libc-alpha@sourceware.org References: From: Alejandro Colomar In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Hi Siddhesh, On 4/6/23 16:22, Siddhesh Poyarekar wrote: [...] >> +size_t >> +__strlcpy (char *__restrict dest, const char *__restrict src, size_t size) >> +{ >> + size_t src_length = strlen (src); >> + >> + if (__glibc_unlikely (src_length >= size)) >> + { >> + if (size > 0) >> + { >> + /* Copy the leading portion of the string. The last >> + character is subsequently overwritten with the NUL >> + terminator, but the destination size is usually a >> + multiple of a small power of two, so writing it twice >> + should be more efficient than copying an odd number of >> + bytes. */ >> + memcpy (dest, src, size); >> + dest[size - 1] = '\0'; >> + } >> + } >> + else >> + /* Copy the string and its terminating NUL character. */ >> + memcpy (dest, src, src_length + 1); > > size == 0 is undefined anyway; we return without touching the dest > because that's convenient for us. OK. Is it really convenient? What real code benefits of that behavior? If we remove the conditional it's one less op. Cheers, Alex > >> + return src_length; >> +}