Prevent updating autorevision.h's timestamp when its contents haven't…

… changed Signed-off-by: Giel van Schijndel <me@mortis.eu>
Warzone2100 · Jan 4, 2013 · 3042d58 · 3042d58
1 parent 0dae748
commit 3042d58
Showing 1 changed file with 6 additions and 4 deletions.
diff --git a/src/Makefile.am b/src/Makefile.am
@@ -7,13 +7,15 @@ AM_YFLAGS = -d
 .PHONY: autorevision.h
 
 autorevision.h autorevision.cache:
-	(cd $(top_srcdir) && ./build_tools/autorevision -t h -o  $(abs_top_builddir)/src/autorevision.cache > $(abs_top_builddir)/src/autorevision.h)
-
-BUILT_SOURCES = \
-	$(CLEANFILES)
+	cd $(top_srcdir) && ./build_tools/autorevision -t h -o $(abs_builddir)/autorevision.cache > $(abs_builddir)/autorevision.h.new
+	cmp -s autorevision.h.new autorevision.h || mv -f autorevision.h.new autorevision.h
 
 CLEANFILES = \
+	$(BUILT_SOURCES) \
 	autorevision.cache \
+	autorevision.h.new
+
+BUILT_SOURCES = \
 	autorevision.h \
 	scriptvals_parser.h