Test Trac #4201 (eta reduction)

testsuite/tests/ghc-regress/simplCore/should_compile/Makefile

@@ -17,3 +17,8 @@ T4306:
 	'$(TEST_HC)' -c -O T4306.hs 
 	'$(TEST_HC)' --show-iface T4306.hi | grep 'wupd ::'
 
+T4201:
+	$(RM) -f rm -f T4201.hi T4201.o
+	'$(TEST_HC)' -c -O T4201.hs 
+	'$(TEST_HC)' --show-iface T4201.hi | grep 'Unfolding.*sym'
+

testsuite/tests/ghc-regress/simplCore/should_compile/T4201.hs

+module Eta where
+
+data T = MkT 
+newtype Foo = Foo T
+
+lift :: Foo -> T
+lift (Foo x) = bof x	
+  -- The point is that we expect 
+  --   lift = bof |> co
+  -- not
+  --   lift = \fx -> bof (fx |> co)
+
+bof :: T -> T
+{-# NOINLINE bof #-}
+bof MkT = MkT

testsuite/tests/ghc-regress/simplCore/should_compile/T4201.stdout

+       Unfolding: (Eta.bof `cast` (sym Eta.NTCo:Foo -> Eta.T)) -}

testsuite/tests/ghc-regress/simplCore/should_compile/all.T

@@ -73,6 +73,11 @@ test('T4306',
      run_command,
      ['$MAKE -s --no-print-directory T4306'])
 
+test('T4201',
+     normal,
+     run_command,
+     ['$MAKE -s --no-print-directory T4201'])
+
 test('T3772',
 #      only_ways(['optc','optasm']), 
      extra_clean(['T3772_A.hi', 'T3772_A.o']),