Remove redundant constraints from libraries, discovered by -fwarn-redundant-constraints

This patch affects libraries, and requires a submodule update.

Some other libraries, maintained by others, have redundant constraints,
namely:
           containers
           haskeline
           transformers
           binary

I have suppressed the redundant-constraint warnings by settings in
           validate-settings.mk
(in this commit)

12 files changed, 40 insertions, 37 deletions

diff --git a/libraries/array b/libraries/array
-Subproject 4baaf0b6d1e7498f529e41eaa3a065cfa84b078
+Subproject e69fab76b5b15d7e7f413edb936faab30d05b8a
diff --git a/libraries/base/Data/Data.hs b/libraries/base/Data/Data.hs
index 8f1e5f4735..dce610b1d7 100644
--- a/libraries/base/Data/Data.hs
+++ b/libraries/base/Data/Data.hs
@@ -1064,7 +1064,7 @@ ratioConstr = mkConstr ratioDataType ":%" [] Infix
 ratioDataType :: DataType
 ratioDataType = mkDataType "GHC.Real.Ratio" [ratioConstr]
 
-instance (Data a, Integral a) => Data (Ratio a) where
+instance Data a => Data (Ratio a) where
   gfoldl k z (a :% b) = z (:%) `k` a `k` b
   toConstr _ = ratioConstr
   gunfold k z c | constrIndex c == 1 = k (k (z (:%)))
@@ -1303,7 +1303,7 @@ instance (Data a, Data b, Data c, Data d, Data e, Data f, Data g)
 
 ------------------------------------------------------------------------------
 
-instance (Data a, Typeable a) => Data (Ptr a) where
+instance Data a => Data (Ptr a) where
   toConstr _   = error "Data.Data.toConstr(Ptr)"
   gunfold _ _  = error "Data.Data.gunfold(Ptr)"
   dataTypeOf _ = mkNoRepType "GHC.Ptr.Ptr"
@@ -1311,7 +1311,7 @@ instance (Data a, Typeable a) => Data (Ptr a) where
 
 ------------------------------------------------------------------------------
 
-instance (Data a, Typeable a) => Data (ForeignPtr a) where
+instance Data a => Data (ForeignPtr a) where
   toConstr _   = error "Data.Data.toConstr(ForeignPtr)"
   gunfold _ _  = error "Data.Data.gunfold(ForeignPtr)"
   dataTypeOf _ = mkNoRepType "GHC.ForeignPtr.ForeignPtr"
@@ -1320,7 +1320,7 @@ instance (Data a, Typeable a) => Data (ForeignPtr a) where
 ------------------------------------------------------------------------------
 -- The Data instance for Array preserves data abstraction at the cost of
 -- inefficiency. We omit reflection services for the sake of data abstraction.
-instance (Typeable a, Data a, Data b, Ix a) => Data (Array a b)
+instance (Data a, Data b, Ix a) => Data (Array a b)
  where
   gfoldl f z a = z (listArray (bounds a)) `f` (elems a)
   toConstr _   = error "Data.Data.toConstr(Array)"
diff --git a/libraries/base/Data/Foldable.hs b/libraries/base/Data/Foldable.hs
index ed32879d28..a745f66092 100644
--- a/libraries/base/Data/Foldable.hs
+++ b/libraries/base/Data/Foldable.hs
@@ -56,7 +56,7 @@ import Data.Monoid
 import Data.Ord
 import Data.Proxy
 
-import GHC.Arr  ( Array(..), Ix(..), elems, numElements,
+import GHC.Arr  ( Array(..), elems, numElements,
                   foldlElems, foldrElems,
                   foldlElems', foldrElems',
                   foldl1Elems, foldr1Elems)
@@ -254,7 +254,7 @@ instance Foldable ((,) a) where
 
     foldr f z (_, y) = f y z
 
-instance Ix i => Foldable (Array i) where
+instance Foldable (Array i) where
     foldr = foldrElems
     foldl = foldlElems
     foldl' = foldlElems'
diff --git a/libraries/base/GHC/Arr.hs b/libraries/base/GHC/Arr.hs
index cefef97f0f..8b7a2afae0 100644
--- a/libraries/base/GHC/Arr.hs
+++ b/libraries/base/GHC/Arr.hs
@@ -450,7 +450,7 @@ unsafeArray :: Ix i => (i,i) -> [(Int, e)] -> Array i e
 unsafeArray b ies = unsafeArray' b (rangeSize b) ies
 
 {-# INLINE unsafeArray' #-}
-unsafeArray' :: Ix i => (i,i) -> Int -> [(Int, e)] -> Array i e
+unsafeArray' :: (i,i) -> Int -> [(Int, e)] -> Array i e
 unsafeArray' (l,u) n@(I# n#) ies = runST (ST $ \s1# ->
     case newArray# n# arrEleBottom s1# of
         (# s2#, marr# #) ->
@@ -465,7 +465,7 @@ fill marr# (I# i#, e) next
              s2# -> next s2#
 
 {-# INLINE done #-}
-done :: Ix i => i -> i -> Int -> MutableArray# s e -> STRep s (Array i e)
+done :: i -> i -> Int -> MutableArray# s e -> STRep s (Array i e)
 -- See NB on 'fill'
 -- Make sure it is strict in 'n'
 done l u n@(I# _) marr#
@@ -535,18 +535,18 @@ badSafeIndex i' n = error ("Error in array index; " ++ show i' ++
                         " not in range [0.." ++ show n ++ ")")
 
 {-# INLINE unsafeAt #-}
-unsafeAt :: Ix i => Array i e -> Int -> e
+unsafeAt :: Array i e -> Int -> e
 unsafeAt (Array _ _ _ arr#) (I# i#) =
     case indexArray# arr# i# of (# e #) -> e
 
 -- | The bounds with which an array was constructed.
 {-# INLINE bounds #-}
-bounds :: Ix i => Array i e -> (i,i)
+bounds :: Array i e -> (i,i)
 bounds (Array l u _ _) = (l,u)
 
 -- | The number of elements in the array.
 {-# INLINE numElements #-}
-numElements :: Ix i => Array i e -> Int
+numElements :: Array i e -> Int
 numElements (Array _ _ n _) = n
 
 -- | The list of indices of an array in ascending order.
@@ -556,13 +556,13 @@ indices (Array l u _ _) = range (l,u)
 
 -- | The list of elements of an array in index order.
 {-# INLINE elems #-}
-elems :: Ix i => Array i e -> [e]
+elems :: Array i e -> [e]
 elems arr@(Array _ _ n _) =
     [unsafeAt arr i | i <- [0 .. n - 1]]
 
 -- | A right fold over the elements
 {-# INLINABLE foldrElems #-}
-foldrElems :: Ix i => (a -> b -> b) -> b -> Array i a -> b
+foldrElems :: (a -> b -> b) -> b -> Array i a -> b
 foldrElems f b0 = \ arr@(Array _ _ n _) ->
   let
     go i | i == n    = b0
@@ -571,7 +571,7 @@ foldrElems f b0 = \ arr@(Array _ _ n _) ->
 
 -- | A left fold over the elements
 {-# INLINABLE foldlElems #-}
-foldlElems :: Ix i => (b -> a -> b) -> b -> Array i a -> b
+foldlElems :: (b -> a -> b) -> b -> Array i a -> b
 foldlElems f b0 = \ arr@(Array _ _ n _) ->
   let
     go i | i == (-1) = b0
@@ -580,7 +580,7 @@ foldlElems f b0 = \ arr@(Array _ _ n _) ->
 
 -- | A strict right fold over the elements
 {-# INLINABLE foldrElems' #-}
-foldrElems' :: Ix i => (a -> b -> b) -> b -> Array i a -> b
+foldrElems' :: (a -> b -> b) -> b -> Array i a -> b
 foldrElems' f b0 = \ arr@(Array _ _ n _) ->
   let
     go i a | i == (-1) = a
@@ -589,7 +589,7 @@ foldrElems' f b0 = \ arr@(Array _ _ n _) ->
 
 -- | A strict left fold over the elements
 {-# INLINABLE foldlElems' #-}
-foldlElems' :: Ix i => (b -> a -> b) -> b -> Array i a -> b
+foldlElems' :: (b -> a -> b) -> b -> Array i a -> b
 foldlElems' f b0 = \ arr@(Array _ _ n _) ->
   let
     go i a | i == n    = a
@@ -598,7 +598,7 @@ foldlElems' f b0 = \ arr@(Array _ _ n _) ->
 
 -- | A left fold over the elements with no starting value
 {-# INLINABLE foldl1Elems #-}
-foldl1Elems :: Ix i => (a -> a -> a) -> Array i a -> a
+foldl1Elems :: (a -> a -> a) -> Array i a -> a
 foldl1Elems f = \ arr@(Array _ _ n _) ->
   let
     go i | i == 0    = unsafeAt arr 0
@@ -608,7 +608,7 @@ foldl1Elems f = \ arr@(Array _ _ n _) ->
 
 -- | A right fold over the elements with no starting value
 {-# INLINABLE foldr1Elems #-}
-foldr1Elems :: Ix i => (a -> a -> a) -> Array i a -> a
+foldr1Elems :: (a -> a -> a) -> Array i a -> a
 foldr1Elems f = \ arr@(Array _ _ n _) ->
   let
     go i | i == n-1  = unsafeAt arr i
@@ -653,7 +653,7 @@ unsafeAccumArray :: Ix i => (e -> a -> e) -> e -> (i,i) -> [(Int, a)] -> Array i
 unsafeAccumArray f initial b ies = unsafeAccumArray' f initial b (rangeSize b) ies
 
 {-# INLINE unsafeAccumArray' #-}
-unsafeAccumArray' :: Ix i => (e -> a -> e) -> e -> (i,i) -> Int -> [(Int, a)] -> Array i e
+unsafeAccumArray' :: (e -> a -> e) -> e -> (i,i) -> Int -> [(Int, a)] -> Array i e
 unsafeAccumArray' f initial (l,u) n@(I# n#) ies = runST (ST $ \s1# ->
     case newArray# n# initial s1#          of { (# s2#, marr# #) ->
     foldr (adjust f marr#) (done l u n marr#) ies s2# })
@@ -684,7 +684,7 @@ arr@(Array l u n _) // ies =
     unsafeReplace arr [(safeIndex (l,u) n i, e) | (i, e) <- ies]
 
 {-# INLINE unsafeReplace #-}
-unsafeReplace :: Ix i => Array i e -> [(Int, e)] -> Array i e
+unsafeReplace :: Array i e -> [(Int, e)] -> Array i e
 unsafeReplace arr ies = runST (do
     STArray l u n marr# <- thawSTArray arr
     ST (foldr (fill marr#) (done l u n marr#) ies))
@@ -701,13 +701,13 @@ accum f arr@(Array l u n _) ies =
     unsafeAccum f arr [(safeIndex (l,u) n i, e) | (i, e) <- ies]
 
 {-# INLINE unsafeAccum #-}
-unsafeAccum :: Ix i => (e -> a -> e) -> Array i e -> [(Int, a)] -> Array i e
+unsafeAccum :: (e -> a -> e) -> Array i e -> [(Int, a)] -> Array i e
 unsafeAccum f arr ies = runST (do
     STArray l u n marr# <- thawSTArray arr
     ST (foldr (adjust f marr#) (done l u n marr#) ies))
 
 {-# INLINE [1] amap #-}
-amap :: Ix i => (a -> b) -> Array i a -> Array i b
+amap :: (a -> b) -> Array i a -> Array i b
 amap f arr@(Array l u n@(I# n#) _) = runST (ST $ \s1# ->
     case newArray# n# arrEleBottom s1# of
         (# s2#, marr# #) ->
@@ -786,7 +786,7 @@ cmpIntArray arr1@(Array l1 u1 n1 _) arr2@(Array l2 u2 n2 _) =
 ----------------------------------------------------------------------
 -- Array instances
 
-instance Ix i => Functor (Array i) where
+instance Functor (Array i) where
     fmap = amap
 
 instance (Ix i, Eq e) => Eq (Array i e) where
@@ -845,7 +845,7 @@ readSTArray marr@(STArray l u n _) i =
     unsafeReadSTArray marr (safeIndex (l,u) n i)
 
 {-# INLINE unsafeReadSTArray #-}
-unsafeReadSTArray :: Ix i => STArray s i e -> Int -> ST s e
+unsafeReadSTArray :: STArray s i e -> Int -> ST s e
 unsafeReadSTArray (STArray _ _ _ marr#) (I# i#)
     = ST $ \s1# -> readArray# marr# i# s1#
 
@@ -855,7 +855,7 @@ writeSTArray marr@(STArray l u n _) i e =
     unsafeWriteSTArray marr (safeIndex (l,u) n i) e
 
 {-# INLINE unsafeWriteSTArray #-}
-unsafeWriteSTArray :: Ix i => STArray s i e -> Int -> e -> ST s ()
+unsafeWriteSTArray :: STArray s i e -> Int -> e -> ST s ()
 unsafeWriteSTArray (STArray _ _ _ marr#) (I# i#) e = ST $ \s1# ->
     case writeArray# marr# i# e s1# of
         s2# -> (# s2#, () #)
@@ -863,7 +863,7 @@ unsafeWriteSTArray (STArray _ _ _ marr#) (I# i#) e = ST $ \s1# ->
 ----------------------------------------------------------------------
 -- Moving between mutable and immutable
 
-freezeSTArray :: Ix i => STArray s i e -> ST s (Array i e)
+freezeSTArray :: STArray s i e -> ST s (Array i e)
 freezeSTArray (STArray l u n@(I# n#) marr#) = ST $ \s1# ->
     case newArray# n# arrEleBottom s1#  of { (# s2#, marr'# #) ->
     let copy i# s3# | isTrue# (i# ==# n#) = s3#
@@ -876,12 +876,12 @@ freezeSTArray (STArray l u n@(I# n#) marr#) = ST $ \s1# ->
     (# s4#, Array l u n arr# #) }}}
 
 {-# INLINE unsafeFreezeSTArray #-}
-unsafeFreezeSTArray :: Ix i => STArray s i e -> ST s (Array i e)
+unsafeFreezeSTArray :: STArray s i e -> ST s (Array i e)
 unsafeFreezeSTArray (STArray l u n marr#) = ST $ \s1# ->
     case unsafeFreezeArray# marr# s1#   of { (# s2#, arr# #) ->
     (# s2#, Array l u n arr# #) }
 
-thawSTArray :: Ix i => Array i e -> ST s (STArray s i e)
+thawSTArray :: Array i e -> ST s (STArray s i e)
 thawSTArray (Array l u n@(I# n#) arr#) = ST $ \s1# ->
     case newArray# n# arrEleBottom s1#  of { (# s2#, marr# #) ->
     let copy i# s3# | isTrue# (i# ==# n#) = s3#
@@ -893,7 +893,7 @@ thawSTArray (Array l u n@(I# n#) arr#) = ST $ \s1# ->
     (# s3#, STArray l u n marr# #) }}
 
 {-# INLINE unsafeThawSTArray #-}
-unsafeThawSTArray :: Ix i => Array i e -> ST s (STArray s i e)
+unsafeThawSTArray :: Array i e -> ST s (STArray s i e)
 unsafeThawSTArray (Array l u n arr#) = ST $ \s1# ->
     case unsafeThawArray# arr# s1#      of { (# s2#, marr# #) ->
     (# s2#, STArray l u n marr# #) }
diff --git a/libraries/base/GHC/Event/Array.hs b/libraries/base/GHC/Event/Array.hs
index e0e089f8d1..61cc773007 100644
--- a/libraries/base/GHC/Event/Array.hs
+++ b/libraries/base/GHC/Event/Array.hs
@@ -132,7 +132,7 @@ unsafeWrite' (AC es _ cap) ix a = do
       withForeignPtr es $ \p ->
         pokeElemOff p ix a
 
-unsafeLoad :: Storable a => Array a -> (Ptr a -> Int -> IO Int) -> IO Int
+unsafeLoad :: Array a -> (Ptr a -> Int -> IO Int) -> IO Int
 unsafeLoad (Array ref) load = do
     AC es _ cap <- readIORef ref
     len' <- withForeignPtr es $ \p -> load p cap
@@ -170,7 +170,7 @@ snoc (Array ref) e = do
     unsafeWrite' ac' len e
     writeIORef ref (AC es len' cap)
 
-clear :: Storable a => Array a -> IO ()
+clear :: Array a -> IO ()
 clear (Array ref) = do
   atomicModifyIORef' ref $ \(AC es _ cap) ->
         (AC es 0 cap, ())
diff --git a/libraries/base/GHC/IOArray.hs b/libraries/base/GHC/IOArray.hs
index 33b1804dbb..6c925d3b2f 100644
--- a/libraries/base/GHC/IOArray.hs
+++ b/libraries/base/GHC/IOArray.hs
@@ -54,12 +54,12 @@ newIOArray :: Ix i => (i,i) -> e -> IO (IOArray i e)
 newIOArray lu initial  = stToIO $ do {marr <- newSTArray lu initial; return (IOArray marr)}
 
 -- | Read a value from an 'IOArray'
-unsafeReadIOArray  :: Ix i => IOArray i e -> Int -> IO e
+unsafeReadIOArray  :: IOArray i e -> Int -> IO e
 {-# INLINE unsafeReadIOArray #-}
 unsafeReadIOArray (IOArray marr) i = stToIO (unsafeReadSTArray marr i)
 
 -- | Write a new value into an 'IOArray'
-unsafeWriteIOArray :: Ix i => IOArray i e -> Int -> e -> IO ()
+unsafeWriteIOArray :: IOArray i e -> Int -> e -> IO ()
 {-# INLINE unsafeWriteIOArray #-}
 unsafeWriteIOArray (IOArray marr) i e = stToIO (unsafeWriteSTArray marr i e)
 
diff --git a/libraries/base/GHC/Real.hs b/libraries/base/GHC/Real.hs
index 656a22de74..1a18e6a3ac 100644
--- a/libraries/base/GHC/Real.hs
+++ b/libraries/base/GHC/Real.hs
@@ -103,12 +103,12 @@ notANumber = 0 :% 0
 -- | Extract the numerator of the ratio in reduced form:
 -- the numerator and denominator have no common factor and the denominator
 -- is positive.
-numerator       :: (Integral a) => Ratio a -> a
+numerator       :: Ratio a -> a
 
 -- | Extract the denominator of the ratio in reduced form:
 -- the numerator and denominator have no common factor and the denominator
 -- is positive.
-denominator     :: (Integral a) => Ratio a -> a
+denominator     :: Ratio a -> a
 
 
 -- | 'reduce' is a subsidiary function used only in this module.
@@ -410,7 +410,7 @@ instance  (Integral a)  => RealFrac (Ratio a)  where
     properFraction (x:%y) = (fromInteger (toInteger q), r:%y)
                           where (q,r) = quotRem x y
 
-instance  (Integral a, Show a)  => Show (Ratio a)  where
+instance  (Show a)  => Show (Ratio a)  where
     {-# SPECIALIZE instance Show Rational #-}
     showsPrec p (x:%y)  =  showParen (p > ratioPrec) $
                            showsPrec ratioPrec1 x .
diff --git a/libraries/base/Text/Printf.hs b/libraries/base/Text/Printf.hs
index cc8c462688..2ccbc11c2f 100644
--- a/libraries/base/Text/Printf.hs
+++ b/libraries/base/Text/Printf.hs
@@ -461,7 +461,7 @@ intModifierMap = [
   ("ll", toInteger (minBound :: Int64)),
   ("L", toInteger (minBound :: Int64)) ]
 
-parseIntFormat :: Integral a => a -> String -> FormatParse
+parseIntFormat :: a -> String -> FormatParse
 parseIntFormat _ s =
   case foldr matchPrefix Nothing intModifierMap of
     Just m -> m
diff --git a/libraries/deepseq b/libraries/deepseq
-Subproject a79bee5f5da25353b88759cf5ed8d0df2b59946
+Subproject de1bc894de1ffdd34e6eb8be4fb9e057198060c
diff --git a/libraries/hoopl b/libraries/hoopl
-Subproject d39ddd928e0d691ee571768a613fd10f6f951a4
+Subproject b38e92f67cabfa0d0ed12ac93c2d431f2391de7
diff --git a/libraries/parallel b/libraries/parallel
-Subproject 5b86f00553688195ea3496d9b7052ec1a9a9c2f
+Subproject e4e4228ba94178cf31b97fe81b94bff3de6fce0
diff --git a/mk/validate-settings.mk b/mk/validate-settings.mk
index 46d269f03b..44222d0f36 100644
--- a/mk/validate-settings.mk
+++ b/mk/validate-settings.mk
@@ -104,6 +104,7 @@ utils/haddock_dist_EXTRA_HC_OPTS += -fno-warn-deprecations
 
 # containers uses bitSize at the moment
 libraries/containers_dist-install_EXTRA_HC_OPTS += -fno-warn-deprecations
+libraries/containers_dist-install_EXTRA_HC_OPTS += -fno-warn-redundant-constraints
 
 # On Windows, there are also some unused import warnings
 ifeq "$(HostOS_CPP)" "mingw32"
@@ -113,6 +114,7 @@ endif
 # haskeline has warnings about deprecated use of block/unblock
 libraries/haskeline_dist-install_EXTRA_HC_OPTS += -fno-warn-deprecations
 libraries/haskeline_dist-install_EXTRA_HC_OPTS += -fno-warn-unused-imports
+libraries/haskeline_dist-install_EXTRA_HC_OPTS += -fno-warn-redundant-constraints
 
 # binary upstream has some warnings, so don't use -Werror for it
 libraries/binary_dist-boot_EXTRA_HC_OPTS += -Wwarn
@@ -143,6 +145,7 @@ libraries/dph/dph-lifted-common-install_EXTRA_HC_OPTS += -Wwarn
 # transformers has unused function parameters warnings
 libraries/transformers_dist-boot_EXTRA_HC_OPTS += -fno-warn-unused-matches -fno-warn-unused-imports
 libraries/transformers_dist-install_EXTRA_HC_OPTS += -fno-warn-unused-matches -fno-warn-unused-imports
+libraries/transformers_dist-install_EXTRA_HC_OPTS += -fno-warn-redundant-constraints
 
 # Turn of trustworthy-safe warning
 libraries/base_dist-install_EXTRA_HC_OPTS += -fno-warn-trustworthy-safe