From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id m4wPJGn5lmDVagAAWB0awg (envelope-from ) for ; Sat, 08 May 2021 16:49:45 -0400 Received: by simark.ca (Postfix, from userid 112) id 8A24C1F11C; Sat, 8 May 2021 16:49:45 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,T_DKIM_INVALID,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id E78D31E783 for ; Sat, 8 May 2021 16:49:44 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 524F03857000; Sat, 8 May 2021 20:49:44 +0000 (GMT) Received: from gateway32.websitewelcome.com (gateway32.websitewelcome.com [192.185.145.170]) by sourceware.org (Postfix) with ESMTPS id D2333385800F for ; Sat, 8 May 2021 20:49:41 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org D2333385800F 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 cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway32.websitewelcome.com (Postfix) with ESMTP id 59B41EFBF for ; Sat, 8 May 2021 15:49:41 -0500 (CDT) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with SMTP id fTtNlaCYzMGeEfTtNlhHju; Sat, 08 May 2021 15:49:41 -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=YePrgMSVT90F/BgtZyLnqVsN7ALM2oESD3TTe7sFZXs=; b=nKU89Ehq5/LGJ9v+Sl0TtCX8ET jkv8DtTveez6Of911ATVt0LGNWkzj0k0GIbG5qN+fb0K2O7Sl5WZtFqgiG33GLZf/ErH38mMSZ6mD unPjTy4WQKWB//tDjc6vNTgTn; Received: from 97-122-70-176.hlrn.qwest.net ([97.122.70.176]:41268 helo=localhost.localdomain) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lfTtN-000kQB-3R; Sat, 08 May 2021 14:49:41 -0600 From: Tom Tromey To: Mike Frysinger via Gdb-patches Subject: Re: [PATCH/committed] sim: touch modules target References: <20210508163519.19783-1-vapier@gentoo.org> X-Attribution: Tom Date: Sat, 08 May 2021 14:49:40 -0600 In-Reply-To: <20210508163519.19783-1-vapier@gentoo.org> (Mike Frysinger via Gdb-patches's message of "Sat, 8 May 2021 12:35:19 -0400") Message-ID: <875yzt9cij.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2.50 (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: 97.122.70.176 X-Source-L: No X-Exim-ID: 1lfTtN-000kQB-3R X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 97-122-70-176.hlrn.qwest.net (localhost.localdomain) [97.122.70.176]:41268 X-Source-Auth: tom+tromey.com X-Email-Count: 6 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes 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: , Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" >>>>> "Mike" == Mike Frysinger via Gdb-patches writes: Mike> If there are no updates to the file, touch the result so we don't Mike> keep trying to regenerate it. Normally you don't want to do it this way. I think it will result in recompilations if the inputs change but the output does not. Since it depends on Makefile and all the source files, this may be pretty often. Now, if that's ok with you, it's simpler to just replace the move-if-change with a $(MV). The more common approach is to use a stamp file. So you write: modules.c: modules-c-stamp ; @true modules-c-stamp: ... the existing code, but also touch modules-c-stamp There are a few examples of this idiom already in the tree. hw-config.h uses this, in the same file. You'd also want to add the stamp file to the clean rule. Tom