From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS3215 2.6.0.0/16 X-Spam-Status: No, score=-3.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by dcvr.yhbt.net (Postfix) with ESMTP id D3D741F8C4 for ; Wed, 23 Mar 2022 20:25:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240659AbiCWU1Z (ORCPT ); Wed, 23 Mar 2022 16:27:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230375AbiCWU1X (ORCPT ); Wed, 23 Mar 2022 16:27:23 -0400 Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A6F47EB2F for ; Wed, 23 Mar 2022 13:25:53 -0700 (PDT) Received: by mail-il1-x12f.google.com with SMTP id j15so1813309ila.13 for ; Wed, 23 Mar 2022 13:25:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ttaylorr-com.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=FNO6kwQ0Mlcewj8XX9PtnbrQAvWSOECqM8K2ryLuWMc=; b=f0WHPIIUhBJp7UY5NynXu1IeXNAm0AHh28olykmnEWIlHHASK11X03+z/RZCELSv1R 8tLsQqo+fuKBSR9pkR4Tu7Z+2fzPsjyub25q5G7+4wSq3GvGFZ6+JmPMPCa3NfmEXSgD RTXckQbNxGiYhUmMQQi/eyv7olX+r8mFueZgjBi8T2nDdaH/3MUSE005UY6mpvg+5a6Z AcnPx2fBJbFPTcZKO2N0MVN/BnM2hMP6HL8BPbD0B/WnXPUbuzZRuoP7FOdDgdx2pwGI vnpniXHAQeg9N4l+kiXueyu3fmlSIS1blMDcpNmNgSYDHrmGcv9se8D+lbAjImYQ46Gt Rdfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=FNO6kwQ0Mlcewj8XX9PtnbrQAvWSOECqM8K2ryLuWMc=; b=VSGOjtwpfB4scK5wDd/rVnE/K2jaPDeTQHqLudJQUHgwXr7c4VLvm9CfRMOR1nkc+5 eYECO/PdojC7eI74MqaylFY1zc3qJg/wCPFFhljuQ9RzHwf5ti05IPS+VnXu+xM9HFPn hAdsUGYOOqhXE+vaVwPy7AJE3KqhEtdlDNXo1L++vPr0Ew0cSMag3hkBtphbv6JO6wGK dIxjwN7ndI1oElB3sPInM+MZJvlbD9Y88fPSkL1pPo+KOm1d9kjSl3yRPy3KsjY0Q/Fr ZTk2dOMqOASIEYXtntKkk4/Q9hx30rhJlk3Fhg/o63zVs+ZV9VulTWGuADJz2mPY+KfE SR+Q== X-Gm-Message-State: AOAM530FfKKElLAg3ijmpOkVrNZDSHtRRhpvcH6HbRrjg2pIvZ9IGzB2 J0dHQutqvaLr1pyDvOZn0IewONW8lTbca7z0 X-Google-Smtp-Source: ABdhPJxJeh6s7Z69PxeSzf0bCkNV8LEORFEazz2w/XpVTsGwm2eQvhXsfNhU3RCk0BIZzEgDrqoeJw== X-Received: by 2002:a05:6e02:144d:b0:2c8:5cfb:8fe3 with SMTP id p13-20020a056e02144d00b002c85cfb8fe3mr932802ilo.35.1648067152978; Wed, 23 Mar 2022 13:25:52 -0700 (PDT) Received: from localhost (104-178-186-189.lightspeed.milwwi.sbcglobal.net. [104.178.186.189]) by smtp.gmail.com with ESMTPSA id u5-20020a056e02170500b002c7d08a5d95sm579604ill.45.2022.03.23.13.25.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Mar 2022 13:25:52 -0700 (PDT) Date: Wed, 23 Mar 2022 16:25:46 -0400 From: Taylor Blau To: John Garry Cc: git@vger.kernel.org Subject: Re: [Question] .git folder file updates for changing head commit Message-ID: References: <6fa76f28-063b-8964-c0a2-642dae88f1b3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <6fa76f28-063b-8964-c0a2-642dae88f1b3@huawei.com> Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Mar 23, 2022 at 03:19:06PM +0000, John Garry wrote: > For building the linux perf tool we use the git head commit id as part of > the tool version sting. To save time in re-building, the Makefile rule has a > dependency on .git/HEAD for rebuilding. An alternative approach would be to > compare git log output to check current versus previous build head commit, > but that is seen as inefficient time-wise. Having a Makefile recipe that depends on $GIT_DIR/HEAD seems strange to me. Presumably your Makefile rules would map out which parts of your program depend on each other, and would get invalidated when the source itself changes, no? Perhaps you also care about the commit you're building from in order to embed something into your program. But it seems like you could inject the output of "git rev-parse HEAD" when you construct the version identifier whenever you do need to rebuild. Thanks, Taylor