From: Bernhard M. Wiedemann <bwiedemann@suse.de>
Date: Sat, 1 Jul 2017 09:07:19 +0000 (+0200)
Subject: Allow to override build date
X-Git-Tag: v4.2.4~116
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7160749d5ab184e36a3368f24c3ca83383c9ede;p=thirdparty%2Ftvheadend.git

Allow to override build date

to enable reproducible builds

See https://reproducible-builds.org/ for why this is good
and https://reproducible-builds.org/specs/source-date-epoch/
for the definition of this variable.

The date calls are designed to work with both GNU date and BSD date
---

diff --git a/Makefile b/Makefile
index 9ae581d99..14052f147 100644
--- a/Makefile
+++ b/Makefile
@@ -668,10 +668,16 @@ src/webui/extjs.c: make_webui
 include ${ROOTDIR}/support/${OSENV}.mk
 
 # Build files
+DATE_FMT = %Y-%m-%dT%H:%M:%S%z
+ifdef SOURCE_DATE_EPOCH
+	BUILD_DATE ?= $(shell date -u -d "@$(SOURCE_DATE_EPOCH)" "+$(DATE_FMT)"  2>/dev/null || date -u -r "$(SOURCE_DATE_EPOCH)" "+$(DATE_FMT)" 2>/dev/null || date -u "+$(DATE_FMT)")
+else
+	BUILD_DATE ?= $(shell date "+$(DATE_FMT)")
+endif
 $(BUILDDIR)/timestamp.c: FORCE
 	@mkdir -p $(dir $@)
 	@echo '#include "build.h"' > $@
-	@echo 'const char* build_timestamp = "'`date +%Y-%m-%dT%H:%M:%S%z`'";' >> $@
+	@echo 'const char* build_timestamp = "'$(BUILD_DATE)'";' >> $@
 
 $(BUILDDIR)/timestamp.o: $(BUILDDIR)/timestamp.c
 	$(pCC) -c -o $@ $<