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: AS22989 209.51.188.0/24 X-Spam-Status: No, score=-2.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 865FC1F910 for ; Wed, 16 Nov 2022 00:09:09 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ov5yn-0006Dd-KU; Tue, 15 Nov 2022 19:08:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ov5yi-0006DB-98; Tue, 15 Nov 2022 19:08:34 -0500 Received: from smtp.simplesystems.org ([65.66.246.90]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ov5yg-0007rm-Dy; Tue, 15 Nov 2022 19:08:32 -0500 Received: from scrappy.simplesystems.org (scrappy.simplesystems.org [65.66.246.73]) by smtp.simplesystems.org (8.14.4+Sun/8.14.4) with ESMTP id 2AG086te017269; Tue, 15 Nov 2022 18:08:06 -0600 (CST) Date: Tue, 15 Nov 2022 18:08:06 -0600 (CST) From: Bob Friesenhahn X-X-Sender: bfriesen@scrappy.simplesystems.org To: Sam James cc: Paul Eggert , Aaron Ballman , Zack Weinberg , c-std-porting@lists.linux.dev, Autoconf Development , GCC Development , cfe-commits@lists.llvm.org, Gnulib bugs Subject: Re: How can Autoconf help with the transition to stricter compilation defaults? In-Reply-To: <35EC0D15-150F-4325-8FC9-F31E963B328F@gentoo.org> Message-ID: References: <24ed5604-305a-4343-a1b6-a789e4723849@app.fastmail.com> <251923e7-57be-1611-be10-49c3067adf0d@cs.ucla.edu> <7ef0ce03-d908-649a-a6ee-89fea374d2b1@cs.ucla.edu> <35EC0D15-150F-4325-8FC9-F31E963B328F@gentoo.org> User-Agent: Alpine 2.20 (GSO 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (smtp.simplesystems.org [65.66.246.90]); Tue, 15 Nov 2022 18:08:08 -0600 (CST) Received-SPF: pass client-ip=65.66.246.90; envelope-from=bfriesen@simple.dallas.tx.us; helo=smtp.simplesystems.org X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: bug-gnulib@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gnulib discussion list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnulib-bounces+normalperson=yhbt.net@gnu.org Sender: bug-gnulib-bounces+normalperson=yhbt.net@gnu.org On Tue, 15 Nov 2022, Sam James wrote: > > >> On 13 Nov 2022, at 00:43, Paul Eggert wrote: >> >> On 2022-11-11 07:11, Aaron Ballman wrote: >>> We believe the runtime behavior is sufficiently dangerous to >>> warrant a conservative view that any call to a function will be a call >>> that gets executed at runtime, hence a definitive signature mismatch >>> is something we feel comfortable diagnosing (in some form) by default. >> >> As long as these diagnostics by default do not cause the compiler to exit with nonzero status, we should be OK with Autoconf-generated 'configure' scripts. Although there will be problems with people who run "./configure CFLAGS='-Werror'", that sort of usage has always been problematic and unsupported by Autoconf, so we can simply continue to tell people "don't do that". >> > > Is there somewhere in the autoconf docs we actually say this? > > I've seen a few instances of folks adding it themselves very > early in their configure scripts (which is a pain for distros > anyway) which then ends up affecting the rest. Autoconf can help with this issue due to GCC and some other compilers providing extensions (usually a pragma) to control warnings while compiling the C code. So configure can run without -Werror, but Autoconf could help by providing an easy way for enabling -Werror while compiling the application. Of course the above does not require Autoconf since application developers can figure it out by themselves using preprocessor logic and knowledge of compiler-specific behavior. If Autoconf is able to help, then the convoluted code can be in just one place (in Autoconf). Bob -- Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ Public Key, http://www.simplesystems.org/users/bfriesen/public-key.txt