From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net (mail-out.m-online.net [IPv6:2001:a60:0:28:0:1:25:1]) by sourceware.org (Postfix) with ESMTPS id 837B838425B1 for ; Mon, 9 May 2022 10:07:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 837B838425B1 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=nefkom.net Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4KxcKY3Fc8z1s7tJ; Mon, 9 May 2022 12:07:13 +0200 (CEST) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4KxcKY08xkz1qqkG; Mon, 9 May 2022 12:07:13 +0200 (CEST) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id brFxm_9UddnM; Mon, 9 May 2022 12:07:12 +0200 (CEST) X-Auth-Info: E1swMVULwOhIL4EL9zEA1/8/wc+QlnzPnWidHcb3JTJyfQ0rK/RfEoFPAmO6XZ19 Received: from igel.home (ppp-46-244-189-9.dynamic.mnet-online.de [46.244.189.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Mon, 9 May 2022 12:07:12 +0200 (CEST) Received: by igel.home (Postfix, from userid 1000) id CE72C2C39A5; Mon, 9 May 2022 12:07:11 +0200 (CEST) From: Andreas Schwab To: Florian Weimer via Gcc Cc: Florian Weimer , Ulrich Drepper Subject: Re: -Wformat and u8"" References: <87wnevcb0f.fsf@oldenburg.str.redhat.com> X-Yow: WHOA!! I'm having a RELIGIOUS EXPERIENCE right NOW!! Date: Mon, 09 May 2022 12:07:11 +0200 In-Reply-To: <87wnevcb0f.fsf@oldenburg.str.redhat.com> (Florian Weimer via Gcc's message of "Mon, 09 May 2022 11:26:24 +0200") Message-ID: <87levbkoj4.fsf@igel.home> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE 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: gcc@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 May 2022 10:07:19 -0000 On Mai 09 2022, Florian Weimer via Gcc wrote: > * Ulrich Drepper via Gcc: > >> t.cc: In function ‘int main()’: >> t.cc:5:24: warning: format string is not an array of type ‘char’ [-Wformat=] >> 5 | printf((const char*) u8"test %d\n", 1); >> | ^~~~~~~~~~~~~ > > This is not an aliasing violation because of the exception for char, > right? So the warning does not even highlight theoretical undefined > behavior. > > On the other hand, that cast is still quite ugly. All string-related > functions in the C library currently need it. It might obscure real > type errors. Isn't this a problem with char8_t? In C++20, u8 literals have a distinct type, which is an incompatible change from C++17. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 "And now for something completely different."