Add a test for #481

testsuite/tests/ghc-regress/driver/recomp009/Main.hs

+{-# LANGUAGE TemplateHaskell #-}
+module Main where
+import Sub
+main = print $x

testsuite/tests/ghc-regress/driver/recomp009/Makefile

+TOP=../../../..
+include $(TOP)/mk/boilerplate.mk
+include $(TOP)/mk/test.mk
+
+# Recompilation tests
+
+clean:
+	rm -f *.o *.hi
+	rm -f B.hs C
+
+# bug #481
+
+recomp009: clean
+	cp Sub1.hs Sub.hs
+	'$(TEST_HC)' $(TEST_HC_OPTS) -v0 --make Main.hs
+	./Main
+	sleep 1
+	cp Sub2.hs Sub.hs
+	-'$(TEST_HC)' $(TEST_HC_OPTS) -v0 --make Main.hs
+	./Main

testsuite/tests/ghc-regress/driver/recomp009/Sub1.hs

+{-# LANGUAGE TemplateHaskell #-}
+module Sub where
+x = [| 1 |]

testsuite/tests/ghc-regress/driver/recomp009/Sub2.hs

+{-# LANGUAGE TemplateHaskell #-}
+module Sub where
+x = [| 2 |]

testsuite/tests/ghc-regress/driver/recomp009/all.T

+# Test for #481, a recompilation bug with Template Haskell
+
+test('recomp009',
+     [ clean_cmd('$MAKE -s clean') ],
+     run_command,
+     ['$MAKE -s --no-print-directory recomp009'])
+

testsuite/tests/ghc-regress/driver/recomp009/recomp009.stdout

+1
+2