From b1ea945a6195a6f26f09551eb6024b9ed9ca9f9d Mon Sep 17 00:00:00 2001 From: Tomi Ollila Date: Fri, 14 Feb 2014 21:24:15 +0200 Subject: [PATCH] Re: [PATCH 1/1] emacs: always write emacs/.eldeps when the target is remade --- 77/c0ee99b5babe355c5f6db00d06319c8b8b6ced | 156 ++++++++++++++++++++++ 1 file changed, 156 insertions(+) create mode 100644 77/c0ee99b5babe355c5f6db00d06319c8b8b6ced diff --git a/77/c0ee99b5babe355c5f6db00d06319c8b8b6ced b/77/c0ee99b5babe355c5f6db00d06319c8b8b6ced new file mode 100644 index 000000000..22e48ef11 --- /dev/null +++ b/77/c0ee99b5babe355c5f6db00d06319c8b8b6ced @@ -0,0 +1,156 @@ +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 99E47431FBC + for ; Fri, 14 Feb 2014 11:24:28 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 0 +X-Spam-Level: +X-Spam-Status: No, score=0 tagged_above=-999 required=5 tests=[none] + 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 bQ-++ifRqVFv for ; + Fri, 14 Feb 2014 11:24:23 -0800 (PST) +Received: from guru.guru-group.fi (guru.guru-group.fi [46.183.73.34]) + by olra.theworths.org (Postfix) with ESMTP id 8C7CF431FB6 + for ; Fri, 14 Feb 2014 11:24:23 -0800 (PST) +Received: from guru.guru-group.fi (localhost [IPv6:::1]) + by guru.guru-group.fi (Postfix) with ESMTP id 8D71C1000FA; + Fri, 14 Feb 2014 21:24:15 +0200 (EET) +From: Tomi Ollila +To: Austin Clements +Subject: Re: [PATCH 1/1] emacs: always write emacs/.eldeps when the target is + remade +In-Reply-To: <20140213074944.GY4375@mit.edu> +References: <1390645309-2326-1-git-send-email-tomi.ollila@iki.fi> + <20140213071026.GX4375@mit.edu> + <20140213074944.GY4375@mit.edu> +User-Agent: Notmuch/0.17+69~g761b031 (http://notmuchmail.org) Emacs/24.3.1 + (x86_64-unknown-linux-gnu) +X-Face: HhBM'cA~ +MIME-Version: 1.0 +Content-Type: text/plain +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: Fri, 14 Feb 2014 19:24:28 -0000 + +On Thu, Feb 13 2014, Austin Clements wrote: + +> 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 $@) +> +> I think this patch is good as it is; I was just pointing out that the +> change also has a performance drawback in some situations. (Knowing +> make, there's probably *some* way to get the best of both worlds and +> it's probably really ugly.) + +Ah, now I understand, because emacs/Makefile.local includes emacs/.eldeps +when it notices mtime of emacs/.eldeps changes it restarts itself... + +... to compare with current behaviour: + +$ make +... +$ touch emacs/notmuch.el +$ make +... +$ make +Use "make V=1" to see the verbose compile lines. +EMACS emacs/.eldeps +make: Nothing to be done for `all'. +$ make +Use "make V=1" to see the verbose compile lines. +EMACS emacs/.eldeps +make: Nothing to be done for `all'. +$ make +Use "make V=1" to see the verbose compile lines. +EMACS emacs/.eldeps +make: Nothing to be done for `all'. + +It will rerun emacs -L emacs -batch -l make-deps.el -f batch-make-deps ... +over and over again... + +I thought I figured out a solution involving .eldeps.stamp file but +that turned out to be no-go... (circular dependency netween .eldeps.stamp +and Makefile.local). + +So, with this if one edits emacs/* files and keeps building byte-compiled +versions often, make will both run EMACS emacs/.eldeps and restarting +-- and when moving to edit other files both of the above stops. Without +this change after editing emacs/* files EMACS emacs/.eldeps will be +executed until it is touched or make clean executed (I wonder how make +handles rebuilding emacs/.eldeps while doing make clean ;) + + +Tomi -- 2.26.2