Test Trac #8537

3 files changed, 24 insertions, 0 deletions

diff --git a/testsuite/tests/simplCore/should_compile/T8537.hs b/testsuite/tests/simplCore/should_compile/T8537.hs
new file mode 100644
index 0000000000..f3f8864d65
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T8537.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE GADTs, DataKinds, KindSignatures, FlexibleInstances #-}
+
+module T8537 where
+
+import Data.Functor
+
+data Nat = S !Nat  | Z
+
+infixr 3 :*
+
+data Shape (rank :: Nat) a where
+    Nil  :: Shape Z a
+    (:*) ::  !(a) -> !(Shape r a ) -> Shape  (S r) a
+
+instance Functor (Shape Z) where
+
+    fmap  = \ f Nil -> Nil
+    {-# INLINABLE fmap #-}
+
+    {-# SPECIALIZE fmap :: (Int ->Int )-> (Shape Z Int)-> (Shape Z Int) #-}
diff --git a/testsuite/tests/simplCore/should_compile/T8537.stderr b/testsuite/tests/simplCore/should_compile/T8537.stderr
new file mode 100644
index 0000000000..f27ee675a5
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T8537.stderr
@@ -0,0 +1,3 @@
+
+T8537.hs:20:5: Warning:
+    SPECIALISE pragma for non-overloaded function ‛fmap’
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index fa3189865d..ecc88e176e 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -197,3 +197,4 @@ test('T5996',
      normal,
      run_command,
      ['$MAKE -s --no-print-directory T5996'])
+test('T8537', normal, compile, [''])