From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 121209 invoked by alias); 27 Aug 2018 20:22:09 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 121196 invoked by uid 89); 27 Aug 2018 20:22:08 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-3.0 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: gateway20.websitewelcome.com Received: from gateway20.websitewelcome.com (HELO gateway20.websitewelcome.com) (192.185.68.24) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 27 Aug 2018 20:22:06 +0000 Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 48022400D857B for ; Mon, 27 Aug 2018 15:22:05 -0500 (CDT) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id uO1GfOJcmaSeyuO1OfshCW; Mon, 27 Aug 2018 15:22:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=W1gEsfdbKB1J14QM0XJssuKLCD/+DOpiKa3m5KGvrxo=; b=nn1gqUqsZpgTtKIPxdrl2Ws9nM rM09PcpSa7nD7g4iKjTbgVD8LYXfSFfIVqcW35JNoSDNSuVPvHzprVkUHaDWVVxT3Q4axoEHvUkCu PTI74hvCOXlY/qA8cELDwvnrO; Received: from 75-166-85-72.hlrn.qwest.net ([75.166.85.72]:40258 helo=bapiya) by box5379.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1fuO1G-001jtR-KZ; Mon, 27 Aug 2018 15:21:50 -0500 From: Tom Tromey To: Simon Marchi Cc: Tom Tromey , Subject: Re: [PATCH 2/9] Use unsigned as base type for some enums References: <20180827145620.11055-1-tom@tromey.com> <20180827145620.11055-3-tom@tromey.com> <86e5c223-9fcc-ad6c-7c29-63037f4bdb74@ericsson.com> Date: Mon, 27 Aug 2018 20:22:00 -0000 In-Reply-To: <86e5c223-9fcc-ad6c-7c29-63037f4bdb74@ericsson.com> (Simon Marchi's message of "Mon, 27 Aug 2018 15:21:43 -0400") Message-ID: <87r2ijy2zm.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-SW-Source: 2018-08/txt/msg00669.txt.bz2 >>>>> "Simon" == Simon Marchi writes: Simon> Can you give an example of how the error manifests itself (I'm not really Simon> familiar with -fsanitize=undefined). Is the error reported at compile-time Simon> or run-time? I'm not able to make a synthetic standalone example to reproduce Simon> the error. You will get an error at runtime, and with the flags added by the last patch in the series, a crash. The error looks somewhat like the error from the expression dumping patch: runtime error: load of value 2887952, which is not a valid value for type 'exp_opcode' (I don't have an exact error handy, this was just taken from the other patch.) Simon> In any case, that LGTM if that makes the compiler happy. If the error reported Simon> by -fsanitize=undefined is at run-time, could we add a static assert in there Simon> to make sure the underlying types of types used with DEF_ENUM_FLAGS_TYPE are Simon> unsigned, to get a compilation error? With the final patch, any UB will cause gdb to crash (in development mode), presumably leading to a test suite failure. I think it isn't necessary to require unsigned as the underlying type -- any type will do. However I don't know how to assert that. Tom