From: Austin Clements Date: Thu, 13 Feb 2014 07:49:44 +0000 (+1900) Subject: Re: [PATCH 1/1] emacs: always write emacs/.eldeps when the target is remade X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=e91af7858042fabf3f3bfa5d33505981e2dff045;p=notmuch-archives.git Re: [PATCH 1/1] emacs: always write emacs/.eldeps when the target is remade --- diff --git a/9a/6ff041cd37a789da8faafeeccadfdead362cb0 b/9a/6ff041cd37a789da8faafeeccadfdead362cb0 new file mode 100644 index 000000000..62bd0741b --- /dev/null +++ b/9a/6ff041cd37a789da8faafeeccadfdead362cb0 @@ -0,0 +1,144 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id 3BFE7431FBD + for ; Wed, 12 Feb 2014 23:49:54 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: -0.7 +X-Spam-Level: +X-Spam-Status: No, score=-0.7 tagged_above=-999 required=5 + tests=[RCVD_IN_DNSWL_LOW=-0.7] autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id nG9ZHu96khMX for ; + Wed, 12 Feb 2014 23:49:48 -0800 (PST) +Received: from dmz-mailsec-scanner-5.mit.edu (dmz-mailsec-scanner-5.mit.edu + [18.7.68.34]) + by olra.theworths.org (Postfix) with ESMTP id 86CDB431FAE + for ; Wed, 12 Feb 2014 23:49:48 -0800 (PST) +X-AuditID: 12074422-f79526d000000c47-d0-52fc791ba2c6 +Received: from mailhub-auth-2.mit.edu ( [18.7.62.36]) + (using TLS with cipher AES256-SHA (256/256 bits)) + (Client did not present a certificate) + by dmz-mailsec-scanner-5.mit.edu (Symantec Messaging Gateway) with SMTP + id 7B.EF.03143.B197CF25; Thu, 13 Feb 2014 02:49:47 -0500 (EST) +Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) + by mailhub-auth-2.mit.edu (8.13.8/8.9.2) with ESMTP id s1D7nlUT005891; + Thu, 13 Feb 2014 02:49:47 -0500 +Received: from awakening.csail.mit.edu (awakening.csail.mit.edu [18.26.4.91]) + (authenticated bits=0) + (User authenticated as amdragon@ATHENA.MIT.EDU) + by outgoing.mit.edu (8.13.8/8.12.4) with ESMTP id s1D7njKj030365 + (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); + Thu, 13 Feb 2014 02:49:46 -0500 +Received: from amthrax by awakening.csail.mit.edu with local (Exim 4.80) + (envelope-from ) + id 1WDr3I-0004i2-MB; Thu, 13 Feb 2014 02:49:44 -0500 +Date: Thu, 13 Feb 2014 02:49:44 -0500 +From: Austin Clements +To: Tomi Ollila +Subject: Re: [PATCH 1/1] emacs: always write emacs/.eldeps when the target is + remade +Message-ID: <20140213074944.GY4375@mit.edu> +References: <1390645309-2326-1-git-send-email-tomi.ollila@iki.fi> + <20140213071026.GX4375@mit.edu> +MIME-Version: 1.0 +Content-Type: text/plain; charset=us-ascii +Content-Disposition: inline +In-Reply-To: +User-Agent: Mutt/1.5.21 (2010-09-15) +X-Brightmail-Tracker: + H4sIAAAAAAAAA+NgFmpmleLIzCtJLcpLzFFi42IRYrdT0ZWu/BNksKrR1uL6zZnMFm9WzmN1 + YPI4/HUhi8ezVbeYA5iiuGxSUnMyy1KL9O0SuDL+fdYvmCFa0bX/J0sD432BLkZODgkBE4nD + T28zQdhiEhfurWfrYuTiEBKYzSSxfvpDdghnI6PExLVfwaqEBE4zSTTczIFILGGU6FizhBkk + wSKgKvFwUSMLiM0moCGxbf9yRhBbREBF4kHbelYQm1lAWuLb72awQcICYRIzF50G6+UV0JY4 + vXceK8TQTkaJy1ffQyUEJU7OfMIC0awlcePfS6BmDrBBy/9xgIQ5BQwkbpyeCzZfFGjXlJPb + 2CYwCs1C0j0LSfcshO4FjMyrGGVTcqt0cxMzc4pTk3WLkxPz8lKLdE31cjNL9FJTSjcxgsPa + RWkH48+DSocYBTgYlXh4NWb8DhJiTSwrrsw9xCjJwaQkynuk/E+QEF9SfkplRmJxRnxRaU5q + 8SFGCQ5mJRFeGQmgHG9KYmVValE+TEqag0VJnLfW4leQkEB6YklqdmpqQWoRTFaGg0NJgvcK + yFDBotT01Iq0zJwShDQTByfIcB6g4ftBaniLCxJzizPTIfKnGBWlxHlFQBICIImM0jy4Xlja + ecUoDvSKMO91kCoeYMqC634FNJgJaHBq1G+QwSWJCCmpBsbm4CiFzo+81otuP2qXmPCaS7Aj + 54DA26h+njnsVg5Sp/kr9zjH7FvG7LddhHf3tLCtvmJFblvryzpSn5TV/Xn3K2O/5zEPi0J2 + U93w0JvnGo782XZzyiqeBTdSzwnNCXZaOn3jUxnxhG/1pWLxPA7xsx662FX+l5mctSQ+yzWT + cf+rLl/xuUosxRmJhlrMRcWJALJ6dn0WAwAA +Cc: notmuch@notmuchmail.org +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Thu, 13 Feb 2014 07:49:54 -0000 + +Quoth Tomi Ollila on Feb 13 at 9:26 am: +> On Thu, Feb 13 2014, Austin Clements wrote: +> +> > Quoth Tomi Ollila on Jan 25 at 12:21 pm: +> >> So that the target is newer than its prerequisites. +> >> --- +> >> emacs/Makefile.local | 3 +-- +> >> 1 file changed, 1 insertion(+), 2 deletions(-) +> >> +> >> diff --git a/emacs/Makefile.local b/emacs/Makefile.local +> >> index 42bfbd9..d5d402e 100644 +> >> --- a/emacs/Makefile.local +> >> +++ b/emacs/Makefile.local +> >> @@ -32,8 +32,7 @@ emacs_bytecode = $(emacs_sources:.el=.elc) +> >> ifeq ($(HAVE_EMACS),1) +> >> $(dir)/.eldeps: $(dir)/Makefile.local $(dir)/make-deps.el $(emacs_sources) +> >> $(call quiet,EMACS) --directory emacs -batch -l make-deps.el \ +> >> - -f batch-make-deps $(emacs_sources) > $@.tmp && \ +> >> - (cmp -s $@.tmp $@ || mv $@.tmp $@) +> >> + -f batch-make-deps $(emacs_sources) > $@.tmp && mv $@.tmp $@ +> >> -include $(dir)/.eldeps +> >> endif +> >> CLEAN+=$(dir)/.eldeps $(dir)/.eldeps.tmp +> > +> > Is this just so the rule doesn't get run again on the next make +> > invocation (unless, of course, a dependent changed)? +> +> Basically yes. I did multiple builds in rapid succession when developing +> something and this thing confused me quite a lot in the beginning... +> +> > Interestingly, if any of the dependents have changed, but in ways that +> > don't affect .eldeps, this change will make the build more expensive +> > because it will trigger a make restart after .eldeps is updated. +> +> I wondered what was the reason for the recipe you've chosen here, has +> it something to do with inodes or something ;) (and were going to ask +> an alternative to touch (or even : > $@) the target... +> +> ... but now I understand. E.g. change in notmuch-lib.el will cause *all* +> .el files to be re-bytecompiled after this change. + +This is unrelated to the cmp in the recipe. A change in +notmuch-lib.el *must* cause almost all .el files to be recompiled +because they almost all require it and may use macros from it. If you +touch, e.g., notmuch-hello.el, you'll see that very little is rebuilt +(with or without this patch). + +> An alternative to this patch would be adding a message to the rule +> which informs user to touch .eldeps to avoid re-doing .eldeps if +> that irritates one :D +> +> something like: +> +> (cmp -s $@.tmp $@ && \ +> echo "touch $@ to avoid redoing this target" || mv $@.tmp $@) + +I think this patch is good as it is; I was just pointing out that the +change also has a performance drawback in some situations. (Knowing +make, there's probably *some* way to get the best of both worlds and +it's probably really ugly.) + +> Thanks, +> +> Tomi