+prefix := @prefix@
+exec_prefix := @exec_prefix@
+bindir := @bindir@
+libdir := @libdir@
+includedir := @includedir@
+
+ifneq ($(DESTDIR),)
+# autoconf likes to define some of these in terms of each other
+# so if we want to add a prefix to each one we have to do it this way:
+destdir_prefix=$(DESTDIR)/
+prefix := ${destdir_prefix}${prefix}
+exec_prefix := ${destdir_prefix}${exec_prefix}
+bindir := ${destdir_prefix}${bindir}
+libdir := ${destdir_prefix}${libdir}
+includedir := ${destdir_prefix}${includedir}
+endif