From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x42b.google.com (mail-wr1-x42b.google.com [IPv6:2a00:1450:4864:20::42b]) by sourceware.org (Postfix) with ESMTPS id 29DAA383D02B for ; Sun, 13 Jun 2021 22:30:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 29DAA383D02B Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=jguk.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=jguk.org Received: by mail-wr1-x42b.google.com with SMTP id q5so12342122wrm.1 for ; Sun, 13 Jun 2021 15:30:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jguk.org; s=google; h=to:from:subject:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=cg35WpObjA3v3OEJfXL5lmNwPgnx7TFbvgEVoBfU1UI=; b=cBcMchyXnDxG6gPHdPtO4t+L5WReBcUedhpD6zQcnpVXnfYU6x5ITJ2W/acjJzvkzl vaErv9RhfMZwsDPS4g0NwOyrT7Z94QX6JWBuc03G0vHHZAspwEDkkRDMlH8wXKd6Tcpd pPs8C8i1vJZ/q1tnfRA9w2spQHcPBTprD//AB0fBPLuA7tYXt864aYB+dGfHvKB3kfJp R1u04MRIqu4SxOZ1vAiwXVQZEU43sOhmuT20uWkyTURZkuaqJQS0qcElSjTkNwbKIpO6 mF207WR+wXG9UeApUNaSlOJ5VQXe4wJ+PJ80VeccP2O1NpO+13BdNkOThYlCqtUQ7wk2 V38w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=cg35WpObjA3v3OEJfXL5lmNwPgnx7TFbvgEVoBfU1UI=; b=LXlal267pWE/vGh3xoD1iULNhKidgKrOgL9X0hQgmMo50IQIuSfgMdLRDkkqzgAG8B ZPDkzIA5OcRZZOelRWZWDKRXoT4A+Pn4sI13OJBhR75mWhSvvJMP02OeftFr/TlNrqfH aDBdlLTq3wjjpU676K+oaQKlsTKMH5P6PpY1GE5SBp5VmBPQQFZtwNy/7VMREB57V7na /V3US4rS67C0aGrieacWTqMewEIgaBMTArJhr8dIfuvuyar01SQQ9Inc+Y+wvyZHgBoE wZ162vYGXRG9jxQkQK7WfHaya3SppJR7cGXInNz7Y1n05JJbxLQCiJdeItvIpdEjimls eY9Q== X-Gm-Message-State: AOAM530dyXRYDHxpGMMbrllIkjeg8DkSqfjsAXhJSoiDRy8cpCXtwWn4 aMYDHds7R6ClnooxanlxC52GCm6suxrksA== X-Google-Smtp-Source: ABdhPJwAhGZXCkbwxHNv6+9Srx+IEJX7Eg/lelWZ2X6wctlzssrVExn6xl9V5iH8zNOjzzscQgoukw== X-Received: by 2002:a5d:5752:: with SMTP id q18mr15493818wrw.419.1623623444035; Sun, 13 Jun 2021 15:30:44 -0700 (PDT) Received: from [192.168.0.12] (cpc87345-slou4-2-0-cust172.17-4.cable.virginm.net. [81.101.252.173]) by smtp.gmail.com with ESMTPSA id t1sm14230993wrx.28.2021.06.13.15.30.43 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 13 Jun 2021 15:30:43 -0700 (PDT) To: gcc-help From: Jonny Grant Subject: gcc warn when pointers not checked non-null before de-referencing. Message-ID: <0a9ccbb7-135a-b342-e5cb-35b7c6a44a00@jguk.org> Date: Sun, 13 Jun 2021 23:30:42 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham 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: Sun, 13 Jun 2021 22:30:48 -0000 Hello This isn't real code, just an example to show. I've tried with: -Wall -Wextra -O2 and some other warnings, but couldn't get this to generate a warning that *g was possibly de-referenced. May I ask, does GCC have a way to get warnings when pointers are not checked? I had a look but -Wnull-dereference didn't help. #include #include void f(int * g) { *g = 1; if(NULL == g) { exit(1); } } Best regards Jonny