Move IP, Symbol, Nat to ghc-prim

This motivation is to declare class IP much earlier (in ghc-prim),
so that implicit parameters (which depend on IP) is available
to library code, notably the 'error' function.

* Move class IP from base:GHC.IP
                to ghc-prim:GHC.Classes
* Delete module GHC.IP from base

* Move types Symbol and Nat
      from base:GHC.TypeLits
      to ghc-prim:GHC.Types

There was a name clash in GHC.RTS.Flags, where I renamed
the local type Nat to RtsNat.

6 files changed, 42 insertions, 43 deletions

diff --git a/libraries/base/GHC/IP.hs b/libraries/base/GHC/IP.hs
deleted file mode 100644
index b85c382a43..0000000000
--- a/libraries/base/GHC/IP.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-{-# LANGUAGE Safe #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE FunctionalDependencies #-}
-{-# LANGUAGE KindSignatures #-}
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE NoImplicitPrelude #-}
-{-# LANGUAGE AllowAmbiguousTypes #-}  
-  -- ip :: IP x a => a  is strictly speaking ambiguous, but IP is magic
-
--- | @since 4.6.0.0
-module GHC.IP (IP(..)) where
-
-import GHC.TypeLits
-
--- | The syntax @?x :: a@ is desugared into @IP "x" a@
-class IP (x :: Symbol) a | x -> a where
-  ip :: a
-
-
diff --git a/libraries/base/GHC/RTS/Flags.hsc b/libraries/base/GHC/RTS/Flags.hsc
index 16764e55c1..308aafbf91 100644
--- a/libraries/base/GHC/RTS/Flags.hsc
+++ b/libraries/base/GHC/RTS/Flags.hsc
@@ -51,7 +51,7 @@ import GHC.Word
 type Time = Word64
 
 -- | @'nat'@ defined in @rts/Types.h@
-type Nat = #{type unsigned int}
+type RtsNat = #{type unsigned int}
 
 data GiveGCStats
     = NoGCStats
@@ -78,19 +78,19 @@ instance Enum GiveGCStats where
 data GCFlags = GCFlags
     { statsFile             :: Maybe FilePath
     , giveStats             :: GiveGCStats
-    , maxStkSize            :: Nat
-    , initialStkSize        :: Nat
-    , stkChunkSize          :: Nat
-    , stkChunkBufferSize    :: Nat
-    , maxHeapSize           :: Nat
-    , minAllocAreaSize      :: Nat
-    , minOldGenSize         :: Nat
-    , heapSizeSuggestion    :: Nat
+    , maxStkSize            :: RtsNat
+    , initialStkSize        :: RtsNat
+    , stkChunkSize          :: RtsNat
+    , stkChunkBufferSize    :: RtsNat
+    , maxHeapSize           :: RtsNat
+    , minAllocAreaSize      :: RtsNat
+    , minOldGenSize         :: RtsNat
+    , heapSizeSuggestion    :: RtsNat
     , heapSizeSuggestionAuto :: Bool
     , oldGenFactor          :: Double
     , pcFreeHeap            :: Double
-    , generations           :: Nat
-    , steps                 :: Nat
+    , generations           :: RtsNat
+    , steps                 :: RtsNat
     , squeezeUpdFrames      :: Bool
     , compact               :: Bool -- ^ True <=> "compact all the time"
     , compactThreshold      :: Double
@@ -305,7 +305,7 @@ getGCFlags = do
   ptr <- getGcFlagsPtr
   GCFlags <$> (peekFilePath =<< #{peek GC_FLAGS, statsFile} ptr)
           <*> (toEnum . fromIntegral <$>
-                (#{peek GC_FLAGS, giveStats} ptr :: IO Nat))
+                (#{peek GC_FLAGS, giveStats} ptr :: IO RtsNat))
           <*> #{peek GC_FLAGS, maxStkSize} ptr
           <*> #{peek GC_FLAGS, initialStkSize} ptr
           <*> #{peek GC_FLAGS, stkChunkSize} ptr
@@ -367,7 +367,7 @@ getCCFlags :: IO CCFlags
 getCCFlags = do
   ptr <- getCcFlagsPtr
   CCFlags <$> (toEnum . fromIntegral
-                <$> (#{peek COST_CENTRE_FLAGS, doCostCentres} ptr :: IO Nat))
+                <$> (#{peek COST_CENTRE_FLAGS, doCostCentres} ptr :: IO RtsNat))
           <*> #{peek COST_CENTRE_FLAGS, profilerTicks} ptr
           <*> #{peek COST_CENTRE_FLAGS, msecsPerTick} ptr
 
diff --git a/libraries/base/GHC/TypeLits.hs b/libraries/base/GHC/TypeLits.hs
index 6da103e73c..dafdb57c69 100644
--- a/libraries/base/GHC/TypeLits.hs
+++ b/libraries/base/GHC/TypeLits.hs
@@ -22,7 +22,7 @@ for working with type-level naturals should be defined in a separate library.
 
 module GHC.TypeLits
   ( -- * Kinds
-    Nat, Symbol
+    Nat, Symbol  -- Both declared in GHC.Types in package ghc-prim
 
     -- * Linking type and value level
   , KnownNat, natVal, natVal'
@@ -39,6 +39,7 @@ module GHC.TypeLits
   ) where
 
 import GHC.Base(Eq(..), Ord(..), Bool(True,False), Ordering(..), otherwise)
+import GHC.Types( Nat, Symbol )
 import GHC.Num(Integer)
 import GHC.Base(String)
 import GHC.Show(Show(..))
@@ -49,13 +50,6 @@ import Data.Proxy (Proxy(..))
 import Data.Type.Equality(type (==), (:~:)(Refl))
 import Unsafe.Coerce(unsafeCoerce)
 
--- | (Kind) This is the kind of type-level natural numbers.
-data Nat
-
--- | (Kind) This is the kind of type-level symbols.
-data Symbol
-
-
 --------------------------------------------------------------------------------
 
 -- | This class gives the integer associated with a type-level natural.
diff --git a/libraries/base/base.cabal b/libraries/base/base.cabal
index ba0151af5c..21a8ae7bcb 100644
--- a/libraries/base/base.cabal
+++ b/libraries/base/base.cabal
@@ -231,7 +231,6 @@ Library
         GHC.IO.IOMode
         GHC.IOArray
         GHC.IORef
-        GHC.IP
         GHC.Int
         GHC.List
         GHC.MVar
diff --git a/libraries/ghc-prim/GHC/Classes.hs b/libraries/ghc-prim/GHC/Classes.hs
index 9028f6edcd..1f9ec2d9f8 100644
--- a/libraries/ghc-prim/GHC/Classes.hs
+++ b/libraries/ghc-prim/GHC/Classes.hs
@@ -1,5 +1,9 @@
 {-# LANGUAGE Trustworthy #-}
-{-# LANGUAGE NoImplicitPrelude, MagicHash, StandaloneDeriving, BangPatterns #-}
+{-# LANGUAGE NoImplicitPrelude, MagicHash, StandaloneDeriving, BangPatterns,
+             KindSignatures, DataKinds, MultiParamTypeClasses, FunctionalDependencies #-}
+{-# LANGUAGE AllowAmbiguousTypes #-}
+  -- ip :: IP x a => a  is strictly speaking ambiguous, but IP is magic
+
 {-# OPTIONS_GHC -fno-warn-unused-imports #-}
 -- XXX -fno-warn-unused-imports needed for the GHC.Tuple import below. Sigh.
 {-# OPTIONS_HADDOCK hide #-}
@@ -17,7 +21,13 @@
 --
 -----------------------------------------------------------------------------
 
-module GHC.Classes where
+module GHC.Classes(
+    IP(..),
+    Eq(..), eqInt, neInt,
+    Ord(..), gtInt, geInt, leInt, ltInt, compareInt, compareInt#,
+    (&&), (||), not,
+    divInt#, modInt#
+ ) where
 
 -- GHC.Magic is used in some derived instances
 import GHC.Magic ()
@@ -32,6 +42,13 @@ infixr 2  ||
 
 default ()              -- Double isn't available yet
 
+-- | The syntax @?x :: a@ is desugared into @IP "x" a@
+-- IP is declared very early, so that libraries can take
+-- advantage of the implicit-call-stack feature
+class IP (x :: Symbol) a | x -> a where
+  ip :: a
+
+
 -- | The 'Eq' class defines equality ('==') and inequality ('/=').
 -- All the basic datatypes exported by the "Prelude" are instances of 'Eq',
 -- and 'Eq' may be derived for any datatype whose constituents are also
diff --git a/libraries/ghc-prim/GHC/Types.hs b/libraries/ghc-prim/GHC/Types.hs
index 808e44f137..e893974116 100644
--- a/libraries/ghc-prim/GHC/Types.hs
+++ b/libraries/ghc-prim/GHC/Types.hs
@@ -22,6 +22,7 @@ module GHC.Types (
         Ordering(..), IO(..),
         isTrue#,
         SPEC(..),
+        Nat, Symbol,
         Coercible,
     ) where
 
@@ -30,6 +31,13 @@ import GHC.Prim
 
 infixr 5 :
 
+-- | (Kind) This is the kind of type-level natural numbers.
+data Nat
+
+-- | (Kind) This is the kind of type-level symbols.
+-- Declared here because class IP needs it
+data Symbol
+
 data [] a = [] | a : [a]
 
 data {-# CTYPE "HsBool" #-} Bool = False | True