From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by sourceware.org (Postfix) with ESMTPS id BF5513861962 for ; Thu, 9 Jul 2020 09:45:40 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org BF5513861962 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=jguk.org Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=jg@jguk.org Received: by mail-wm1-x332.google.com with SMTP id a6so5865319wmm.0 for ; Thu, 09 Jul 2020 02:45:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jguk.org; s=google; h=from:subject:to:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=oAcU+W5r5tqn2w2OBHLvp5tazZQkx8xz/NtwAPvxX+c=; b=Rytun2p5LRcTX58uWP+WOkILRo8GuRFTJ4UrOdb4z5g7GbW78WjQP2X3w9UOhgDAuV 8I/p55CwoF/MyYP/b1mjK3BHZvyhIcljvI2CGXgKBkWOmjMAmQGV2q1T/u3oCtSmyt13 KGcVJ2JjynOp1VYWAhE8bWRHc+laszdQvOFcTZYCAgqNbbD32Cqag5aaOH5BsqmU76/4 BM4F2WnpyRGiiEOAT8PhMlrzpTUFr4Sx9DoVzYofJVIWJ15GUw6hxi23s83hxbDz7QVU UKtSOPnKfiWvf9viUTBRo6SS0IcZ11TVo92eC3MToMCzB6acvdaqoJCnvVZCm++wO0j2 0WHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:subject:to:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=oAcU+W5r5tqn2w2OBHLvp5tazZQkx8xz/NtwAPvxX+c=; b=KXFeQRpPpO1sbzoHGxhysxiUWoxeE7uce2BSHXSExSZa50n00OrGl6Gcu3aGoX8I/j zGPFXBNE1l1o5deDRhocKeXg1G/QeuX6nUa4LQuu/A5b2VrDnIiMWpADBTNxuneWrGo0 mRRp0lSJYeeRtCvhJmbb7peWTtRKUIaAsCsh48eDLB7zQR1NOqwh9aNYtr3RvHFhSUbO uqIr5ZgZ595zNWJY1O6a+yOqVDrZF5psQY93DIEpwi1QqbgQobm33asvC+T4pgwETJlF 4CZ2Kc91w+64aL+RC+ImpwyahyFwA3BUi7if0RTtVBHV/+hOypxoMrzH5Z+Tk88EPzvc 1xhQ== X-Gm-Message-State: AOAM531LxgiV9oVYBHWbF+3fHhAMNyIyuE5YxBaMrib/f/Bt/Xf0zAqq r944438SL4yjVGVO3T9yNZDj5g== X-Google-Smtp-Source: ABdhPJxRZ2G5jrbgV1smWfQSoRT0JAaKvqrkLS6+0bRj/K11PxNcqsewac1IyV3rNV+D7Qdg9wBVeg== X-Received: by 2002:a1c:c38a:: with SMTP id t132mr13076588wmf.1.1594287939774; Thu, 09 Jul 2020 02:45:39 -0700 (PDT) Received: from [192.168.0.12] (cpc87281-slou4-2-0-cust47.17-4.cable.virginm.net. [92.236.12.48]) by smtp.gmail.com with ESMTPSA id a2sm4640718wrn.68.2020.07.09.02.45.38 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 09 Jul 2020 02:45:38 -0700 (PDT) From: Jonny Grant Subject: gcc warn unreached else {} To: gcc-help Message-ID: <3a091703-4842-b738-bb38-fab01e787650@jguk.org> Date: Thu, 9 Jul 2020 10:45:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, PDS_TONAME_EQ_TOLOCAL_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, TXREP, T_SPF_PERMERROR autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-help@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-help mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Jul 2020 09:45:42 -0000 Hello! There is an example below, (my code is not like this example below). I'm reporting a possible issue, and asking if there is a way to detect it in code bases. If it's a real issue I can file a bug report on Bugzilla. Can gcc warn where code will not get to the 'return 3;' below? Cheers, Jonny int main(void) { const int i = 1; if(1 == i) { return 1; } else if(1 != i) { return 2; } else { return 3; } }