# HG changeset patch
# User Bruno Haible <bruno@clisp.org>
# Date 1240171796 -7200
# Node ID f4b420294f4b83e56a505f43c81f14452c10ffc6
# Parent  174a2fed8a76741cb715026bd76d8f293c430827
Don't touch configmake.h if it has not actually changed.

diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-19  Bruno Haible  <bruno@clisp.org>
+
+	* modules/configmake (Makefile.am): When the contents of configmake.h
+	does not change, arrange to preserve its modification time.
+
 2009-04-17  Simon Josefsson  <simon@josefsson.org>
 
 	* top/maint.mk (PO_DOMAIN): New variable, allows overriding of
diff --git a/modules/configmake b/modules/configmake
--- a/modules/configmake
+++ b/modules/configmake
@@ -26,7 +26,7 @@
 # The Automake-defined pkg* macros are appended, in the order
 # listed in the Automake 1.10a+ documentation.
 configmake.h: Makefile
-	rm -f $@-t $@
+	rm -f $@-t
 	{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
 	  echo '#define PREFIX "$(prefix)"'; \
 	  echo '#define EXEC_PREFIX "$(exec_prefix)"'; \
@@ -56,7 +56,12 @@
 	  echo '#define PKGLIBDIR "$(pkglibdir)"'; \
 	  echo '#define PKGLIBEXECDIR "$(pkglibexecdir)"'; \
 	} | sed '/""/d' > $@-t
-	mv $@-t $@
+	if test -f $@ && cmp $@-t $@ > /dev/null; then \
+	  rm -f $@-t; \
+	else \
+	  rm -f $@; mv $@-t $@; \
+	fi
+
 BUILT_SOURCES += configmake.h
 CLEANFILES += configmake.h configmake.h-t