+TEST_EXTENSIONS = .t
+SUFFIXES += .c .t$(EXEEXT) .to
+
+## This unpleasant duplication of rules makes the build system basically work
+## for non-GNU make(1) variants, while GNU Make will associate useful
+## additional dependencies with the test programs. GNU Make seems not to
+## mind the duplicate rules, and uses the second (better) set; non-GNU Make
+## will think the second set refer to bizarrely-named targets which nobody is
+## apparently interested in.