From 81777670685e87174b0c9a46aebfd0695a3ec8b9 Mon Sep 17 00:00:00 2001 From: Austin Clements Date: Thu, 12 Apr 2012 16:38:39 +2000 Subject: [PATCH] [PATCH v2] Record dependencies during build instead of before --- 98/cc631d2a31c6dd2acc6bfe6766b1a39c63a557 | 138 ++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 98/cc631d2a31c6dd2acc6bfe6766b1a39c63a557 diff --git a/98/cc631d2a31c6dd2acc6bfe6766b1a39c63a557 b/98/cc631d2a31c6dd2acc6bfe6766b1a39c63a557 new file mode 100644 index 000000000..e25cbb4d9 --- /dev/null +++ b/98/cc631d2a31c6dd2acc6bfe6766b1a39c63a557 @@ -0,0 +1,138 @@ +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 83F08431FAF + for ; Wed, 11 Apr 2012 13:38:44 -0700 (PDT) +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 7+rNSTTay-Po for ; + Wed, 11 Apr 2012 13:38:43 -0700 (PDT) +Received: from dmz-mailsec-scanner-4.mit.edu (DMZ-MAILSEC-SCANNER-4.MIT.EDU + [18.9.25.15]) + by olra.theworths.org (Postfix) with ESMTP id CD353431FAE + for ; Wed, 11 Apr 2012 13:38:43 -0700 (PDT) +X-AuditID: 1209190f-b7f8a6d000000914-9a-4f85ebd3815b +Received: from mailhub-auth-4.mit.edu ( [18.7.62.39]) + by dmz-mailsec-scanner-4.mit.edu (Symantec Messaging Gateway) with SMTP + id 01.EF.02324.3DBE58F4; Wed, 11 Apr 2012 16:38:43 -0400 (EDT) +Received: from outgoing.mit.edu (OUTGOING-AUTH.MIT.EDU [18.7.22.103]) + by mailhub-auth-4.mit.edu (8.13.8/8.9.2) with ESMTP id q3BKcgMb011757; + Wed, 11 Apr 2012 16:38:42 -0400 +Received: from drake.mit.edu (31-35-38.wireless.csail.mit.edu [128.31.35.38]) + (authenticated bits=0) + (User authenticated as amdragon@ATHENA.MIT.EDU) + by outgoing.mit.edu (8.13.6/8.12.4) with ESMTP id q3BKcfbs013275 + (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=NOT); + Wed, 11 Apr 2012 16:38:42 -0400 (EDT) +Received: from amthrax by drake.mit.edu with local (Exim 4.77) + (envelope-from ) + id 1SI4JM-0006Ur-KN; Wed, 11 Apr 2012 16:38:40 -0400 +From: Austin Clements +To: notmuch@notmuchmail.org +Subject: [PATCH v2] Record dependencies during build instead of before +Date: Wed, 11 Apr 2012 16:38:39 -0400 +Message-Id: <1334176719-24781-1-git-send-email-amdragon@mit.edu> +X-Mailer: git-send-email 1.7.9.1 +In-Reply-To: <1333857710-24511-1-git-send-email-amdragon@mit.edu> +References: <1333857710-24511-1-git-send-email-amdragon@mit.edu> +X-Brightmail-Tracker: + H4sIAAAAAAAAA+NgFtrIIsWRmVeSWpSXmKPExsUixG6nrnv5dau/wepeXovrN2cyOzB6PFt1 + izmAMYrLJiU1J7MstUjfLoEr49+Br0wFj8Qqrn1uYG1g3CTUxcjJISFgIrF91k02CFtM4sK9 + 9WC2kMA+RonLDx26GLmA7A2MEhvWd7BAOCeZJBa1v2OEqJrPKHH+CzuIzSagIbFt/3KwuIiA + tMTOu7NZuxg5OJgF1CT+dKmAhIUF3CRW3jrCDGKzCKhKnDywEKyVV8BB4u3CB4wQRyhIPFt3 + nAnE5hRwlHj5o4MZYpWDxP8lkxgnMPIvYGRYxSibklulm5uYmVOcmqxbnJyYl5dapGuil5tZ + opeaUrqJERQynJL8Oxi/HVQ6xCjAwajEw7trQqu/EGtiWXFl7iFGSQ4mJVHeqa+AQnxJ+SmV + GYnFGfFFpTmpxYcYJTiYlUR4XWa3+AvxpiRWVqUW5cOkpDlYlMR51bTe+QkJpCeWpGanphak + FsFkZTg4lCR4vzwFGipYlJqeWpGWmVOCkGbi4AQZzgM0nPsZUA1vcUFibnFmOkT+FKOilDjv + BZBmAZBERmkeXC8spl8xigO9Isx7EaSKB5gO4LpfAQ1mAhr8eTLI1cUliQgpqQbGtGCBGSWb + lr19JaZzQ2PJMY1TquvWmL47cD+pKnhWhrXTp2liEn+6/Ux/lwReN+lvXeV+c8nOD0uOCf6o + 0fewncr683Ii/w/eXxfNreJMHvqGRVoGy4RNb/kS8sI/eUX3oT0nZL8ueLjw16Xo+nNtvB83 + 1Juo+n3/Petgm9iCm4beE09cumi2UomlOCPRUIu5qDgRAG2Fw77EAgAA +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: Wed, 11 Apr 2012 20:38:44 -0000 + +Previously, the makefile created dependency files in a separate, first +pass. In particular, include-ing the dependency files would cause +make to attempt to rebuild those files using the dependency-generation +rules in the makefile. Unfortunately, this approach required obtuse +rules and silently delayed the start of the build process (by quite a +bit on a clean tree without any dependency files). Worse, this +required the dependency files to themselves depend on all of the +headers the source file depended on, which meant that, if a header +file was removed, the depedency file could not be updated because of a +missing dependency (!), which would cause make to silently fail. + +This patch eliminates the dependency generation rules and instead +generates dependency files as a side-effect of the regular build rule. +On the first build, we don't need to know the dependencies beforehand; +the object file doesn't exist, so it will be built anyway. On +subsequent builds, if a header file is updated, the dependency rules +generated by the previous build will force a rebuild. If a source +file is updated, the dependency rules may be stale, but it doesn't +matter because the updated source file will force a rebuild. + +In the final case above, the stale dependency rules may refer to a +header file that no longer exists but is also no longer needed. In +order to prevent this from breaking the build, we also pass gcc the +-MP option, which generates phony targets for every depended-on header +file, so make won't complain if it can't find them during a later +build. +--- +Sorry, the previous version of this patch was corrupted. Hopefully +this one will be correct. + + Makefile.local | 18 ++++-------------- + 1 files changed, 4 insertions(+), 14 deletions(-) + +diff --git a/Makefile.local b/Makefile.local +index 1131dea..525eda0 100644 +--- a/Makefile.local ++++ b/Makefile.local +@@ -256,22 +256,12 @@ endif + quiet ?= $($(shell echo $1 | sed -e s'/ .*//')) + + %.o: %.cc $(global_deps) ++ @mkdir -p .deps/$(@D) ++ $(call quiet,CXX $(CXXFLAGS)) -c $(FINAL_CXXFLAGS) $< -o $@ -MD -MP -MF .deps/$*.d +- $(call quiet,CXX $(CXXFLAGS)) -c $(FINAL_CXXFLAGS) $< -o $@ + + %.o: %.c $(global_deps) ++ @mkdir -p .deps/$(@D) ++ $(call quiet,CC $(CFLAGS)) -c $(FINAL_CFLAGS) $< -o $@ -MD -MP -MF .deps/$*.d +- $(call quiet,CC $(CFLAGS)) -c $(FINAL_CFLAGS) $< -o $@ +- +-.deps/%.d: %.c $(global_deps) +- @set -e; rm -f $@; mkdir -p $$(dirname $@) ; \ +- $(CC) -M $(CPPFLAGS) $(FINAL_CFLAGS) $< > $@.$$$$ 2>/dev/null ; \ +- sed 's,'$$(basename $*)'\.o[ :]*,$*.o $@ : ,g' < $@.$$$$ > $@; \ +- rm -f $@.$$$$ +- +-.deps/%.d: %.cc $(global_deps) +- @set -e; rm -f $@; mkdir -p $$(dirname $@) ; \ +- $(CXX) -M $(CPPFLAGS) $(FINAL_CXXFLAGS) $< > $@.$$$$ 2>/dev/null ; \ +- sed 's,'$$(basename $*)'\.o[ :]*,$*.o $@ : ,g' < $@.$$$$ > $@; \ +- rm -f $@.$$$$ + + .PHONY : clean + clean: +-- +1.7.9.1 + -- 2.26.2