From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gateway30.websitewelcome.com (gateway30.websitewelcome.com [192.185.168.15]) by sourceware.org (Postfix) with ESMTPS id B992F3858D35 for ; Tue, 30 Jun 2020 20:53:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org B992F3858D35 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=tom@tromey.com Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway30.websitewelcome.com (Postfix) with ESMTP id E1B3A2B05 for ; Tue, 30 Jun 2020 15:53:14 -0500 (CDT) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id qNFijlx2oSxZVqNFijpZ33; Tue, 30 Jun 2020 15:53:14 -0500 X-Authority-Reason: nr=8 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=p5jbvHRnBzW11tufiUfoKzUrMWMYaZ2p/GSMsVZxWuw=; b=diUqPPRqyDS7N/DW9wk6ClOix6 RL9DlYVeDHPY/yYA3tNvzCf44aiK/NI/LUKoXMYjZ+nj7XZm5iiOKRxZTUQwxHw2ecCAhILHS6NJP lvFuvsGLF6oCoZRUSs0ZnXZ/G; Received: from 174-16-104-48.hlrn.qwest.net ([174.16.104.48]:45936 helo=murgatroyd) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1jqNFi-004B3K-J6; Tue, 30 Jun 2020 14:53:14 -0600 From: Tom Tromey To: Simon Marchi via Gdb-patches Subject: Re: [PATCH 2/3] gdb: make macro_expand_next return a gdb::unique_xmalloc_ptr References: <20200628165628.96730-1-simon.marchi@polymtl.ca> <20200628165628.96730-3-simon.marchi@polymtl.ca> X-Attribution: Tom Date: Tue, 30 Jun 2020 14:53:13 -0600 In-Reply-To: <20200628165628.96730-3-simon.marchi@polymtl.ca> (Simon Marchi via Gdb-patches's message of "Sun, 28 Jun 2020 12:56:27 -0400") Message-ID: <87v9j88edi.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 174.16.104.48 X-Source-L: No X-Exim-ID: 1jqNFi-004B3K-J6 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 174-16-104-48.hlrn.qwest.net (murgatroyd) [174.16.104.48]:45936 X-Source-Auth: tom+tromey.com X-Email-Count: 4 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-Spam-Status: No, score=-3027.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, JMQ_SPF_NEUTRAL, RCVD_IN_ABUSEAT, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_NEUTRAL, TXREP 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: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Jun 2020 20:53:33 -0000 >>>>> "Simon" == Simon Marchi via Gdb-patches writes: Simon> I removed the ATTRIBUTE_UNUSED_RESULT on macro_buffer::release, I don't Simon> really understand why it's there. I don't see how this method could be Simon> called without using the result, that would be an obvious memory leak. Simon> The commit that introduced it (4e4a8b932b7 "Add ATTRIBUTE_UNUSED_RESULT Simon> to macro_buffer") doesn't give any details. Sorry about the lack of details! Simon> - /* Release the text of the buffer to the caller, which is now Simon> - responsible for freeing it. */ Simon> - ATTRIBUTE_UNUSED_RESULT char *release () Simon> + /* Release the text of the buffer to the caller. */ Simon> + gdb::unique_xmalloc_ptr release () In the old code, the caller had to remember to free the resulting char*. ATTRIBUTE_UNUSED_RESULT meant that one couldn't write "x.release();" without at least doing something with the result. There was at least one case of this happening, though I didn't read through the thread to find out exactly where it was: https://sourceware.org/pipermail/gdb-patches/2019-February/155835.html Using a unique pointer eliminates this common source of bugs, so I think removing the attribute makes sense. This patch looks fine to me. Tom