Merge remote-tracking branch 'origin/master' into type-nats

Conflicts:
	compiler/coreSyn/CoreLint.lhs
	compiler/deSugar/DsBinds.lhs
	compiler/hsSyn/HsTypes.lhs
	compiler/iface/IfaceType.lhs
	compiler/rename/RnHsSyn.lhs
	compiler/rename/RnTypes.lhs
	compiler/stgSyn/StgLint.lhs
	compiler/typecheck/TcHsType.lhs
	compiler/utils/ListSetOps.lhs

7 files changed, 198 insertions, 297 deletions

diff --git a/compiler/iface/BinIface.hs b/compiler/iface/BinIface.hs
index 8bf6594df5..eff699fd6b 100644
--- a/compiler/iface/BinIface.hs
+++ b/compiler/iface/BinIface.hs
@@ -998,33 +998,10 @@ instance Binary IfaceType where
             putByte bh 3
             put_ bh ag
             put_ bh ah
-    
-        -- Simple compression for common cases of TyConApp
-    put_ bh (IfaceTyConApp IfaceIntTc  [])   = putByte bh 6
-    put_ bh (IfaceTyConApp IfaceCharTc [])   = putByte bh 7
-    put_ bh (IfaceTyConApp IfaceBoolTc [])   = putByte bh 8
-    put_ bh (IfaceTyConApp IfaceListTc [ty]) = do { putByte bh 9; put_ bh ty }
-        -- Unit tuple and pairs
-    put_ bh (IfaceTyConApp (IfaceTupTc BoxedTuple 0) []) = putByte bh 10
-    put_ bh (IfaceTyConApp (IfaceTupTc BoxedTuple 2) [t1,t2])
-      = do { putByte bh 11; put_ bh t1; put_ bh t2 }
-        -- Kind cases
-    put_ bh (IfaceTyConApp IfaceLiftedTypeKindTc [])   = putByte bh 12
-    put_ bh (IfaceTyConApp IfaceOpenTypeKindTc [])     = putByte bh 13
-    put_ bh (IfaceTyConApp IfaceUnliftedTypeKindTc []) = putByte bh 14
-    put_ bh (IfaceTyConApp IfaceUbxTupleKindTc [])     = putByte bh 15
-    put_ bh (IfaceTyConApp IfaceArgTypeKindTc [])      = putByte bh 16
-    put_ bh (IfaceTyConApp IfaceConstraintKindTc [])   = putByte bh 17
-    put_ bh (IfaceTyConApp IfaceSuperKindTc [])        = putByte bh 18
-
     put_ bh (IfaceCoConApp cc tys)
-      = do { putByte bh 19; put_ bh cc; put_ bh tys }
-
-        -- Generic cases
-    put_ bh (IfaceTyConApp (IfaceTc tc) tys)
-      = do { putByte bh 20; put_ bh tc; put_ bh tys }
+      = do { putByte bh 4; put_ bh cc; put_ bh tys }
     put_ bh (IfaceTyConApp tc tys)
-      = do { putByte bh 21; put_ bh tc; put_ bh tys }
+      = do { putByte bh 5; put_ bh tc; put_ bh tys }
 
     put_ bh (IfaceLitTy n)
       = do { putByte bh 30; put_ bh n }
@@ -1044,30 +1021,10 @@ instance Binary IfaceType where
               3 -> do ag <- get bh
                       ah <- get bh
                       return (IfaceFunTy ag ah)
-              
-                -- Now the special cases for TyConApp
-              6 -> return (IfaceTyConApp IfaceIntTc [])
-              7 -> return (IfaceTyConApp IfaceCharTc [])
-              8 -> return (IfaceTyConApp IfaceBoolTc [])
-              9 -> do { ty <- get bh; return (IfaceTyConApp IfaceListTc [ty]) }
-              10 -> return (IfaceTyConApp (IfaceTupTc BoxedTuple 0) [])
-              11 -> do { t1 <- get bh; t2 <- get bh
-                       ; return (IfaceTyConApp (IfaceTupTc BoxedTuple 2) [t1,t2]) }
-              12 -> return (IfaceTyConApp IfaceLiftedTypeKindTc [])
-              13 -> return (IfaceTyConApp IfaceOpenTypeKindTc [])
-              14 -> return (IfaceTyConApp IfaceUnliftedTypeKindTc [])
-              15 -> return (IfaceTyConApp IfaceUbxTupleKindTc [])
-              16 -> return (IfaceTyConApp IfaceArgTypeKindTc [])
-              17 -> return (IfaceTyConApp IfaceConstraintKindTc [])
-              18 -> return (IfaceTyConApp IfaceSuperKindTc [])
-
-              19 -> do { cc <- get bh; tys <- get bh
-                        ; return (IfaceCoConApp cc tys) }
-
-              20 -> do { tc <- get bh; tys <- get bh
-                       ; return (IfaceTyConApp (IfaceTc tc) tys) }
-              21 -> do { tc <- get bh; tys <- get bh
-                        ; return (IfaceTyConApp tc tys) }
+              4 -> do { cc <- get bh; tys <- get bh
+                      ; return (IfaceCoConApp cc tys) }
+              5 -> do { tc <- get bh; tys <- get bh
+                      ; return (IfaceTyConApp tc tys) }
 
               30 -> do n <- get bh
                        return (IfaceLitTy n)
@@ -1088,42 +1045,8 @@ instance Binary IfaceTyLit where
          _ -> panic ("get IfaceTyLit " ++ show tag)
 
 instance Binary IfaceTyCon where
-        -- Int,Char,Bool can't show up here because they can't not be saturated
-   put_ bh IfaceIntTc         = putByte bh 1
-   put_ bh IfaceBoolTc        = putByte bh 2
-   put_ bh IfaceCharTc        = putByte bh 3
-   put_ bh IfaceListTc        = putByte bh 4
-   put_ bh IfacePArrTc        = putByte bh 5
-   put_ bh IfaceLiftedTypeKindTc   = putByte bh 6
-   put_ bh IfaceOpenTypeKindTc     = putByte bh 7
-   put_ bh IfaceUnliftedTypeKindTc = putByte bh 8
-   put_ bh IfaceUbxTupleKindTc     = putByte bh 9
-   put_ bh IfaceArgTypeKindTc      = putByte bh 10
-   put_ bh IfaceConstraintKindTc   = putByte bh 11
-   put_ bh IfaceSuperKindTc        = putByte bh 12
-   put_ bh (IfaceTupTc bx ar)  = do { putByte bh 13; put_ bh bx; put_ bh ar }
-   put_ bh (IfaceTc ext)       = do { putByte bh 14; put_ bh ext }
-   put_ bh (IfaceIPTc n)       = do { putByte bh 15; put_ bh n }
-
-   get bh = do
-        h <- getByte bh
-        case h of
-          1 -> return IfaceIntTc
-          2 -> return IfaceBoolTc
-          3 -> return IfaceCharTc
-          4 -> return IfaceListTc
-          5 -> return IfacePArrTc
-          6 -> return IfaceLiftedTypeKindTc 
-          7 -> return IfaceOpenTypeKindTc 
-          8 -> return IfaceUnliftedTypeKindTc
-          9 -> return IfaceUbxTupleKindTc
-          10 -> return IfaceArgTypeKindTc
-          11 -> return IfaceConstraintKindTc
-          12 -> return IfaceSuperKindTc
-          13 -> do { bx <- get bh; ar <- get bh; return (IfaceTupTc bx ar) }
-          14 -> do { ext <- get bh; return (IfaceTc ext) }
-          15 -> do { n <- get bh; return (IfaceIPTc n) }
-          _  -> panic ("get IfaceTyCon " ++ show h)
+   put_ bh (IfaceTc ext) = put_ bh ext
+   get bh = liftM IfaceTc (get bh)
 
 instance Binary IfaceCoCon where
    put_ bh (IfaceCoAx n)       = do { putByte bh 0; put_ bh n }
@@ -1390,7 +1313,7 @@ instance Binary IfaceDecl where
     put_ _ (IfaceForeign _ _) = 
         error "Binary.put_(IfaceDecl): IfaceForeign"
 
-    put_ bh (IfaceData a1 a2 a3 a4 a5 a6 a7) = do
+    put_ bh (IfaceData a1 a2 a3 a4 a5 a6 a7 a8) = do
         putByte bh 2
         put_ bh (occNameFS a1)
         put_ bh a2
@@ -1399,6 +1322,7 @@ instance Binary IfaceDecl where
         put_ bh a5
         put_ bh a6
         put_ bh a7
+        put_ bh a8
 
     put_ bh (IfaceSyn a1 a2 a3 a4) = do
         putByte bh 3
@@ -1441,8 +1365,9 @@ instance Binary IfaceDecl where
                     a5 <- get bh
                     a6 <- get bh
                     a7 <- get bh
+                    a8 <- get bh
                     occ <- return $! mkOccNameFS tcName a1
-                    return (IfaceData occ a2 a3 a4 a5 a6 a7)
+                    return (IfaceData occ a2 a3 a4 a5 a6 a7 a8)
             3 -> do a1 <- get bh
                     a2 <- get bh
                     a3 <- get bh
diff --git a/compiler/iface/BuildTyCl.lhs b/compiler/iface/BuildTyCl.lhs
index 75b8d91881..4a93a2bbe4 100644
--- a/compiler/iface/BuildTyCl.lhs
+++ b/compiler/iface/BuildTyCl.lhs
@@ -29,6 +29,7 @@ import DataCon
 import Var
 import VarSet
 import BasicTypes
+import ForeignCall
 import Name
 import MkId
 import Class
@@ -56,6 +57,7 @@ buildSynTyCon tc_name tvs rhs rhs_kind parent
 ------------------------------------------------------
 buildAlgTyCon :: Name 
               -> [TyVar]               -- ^ Kind variables and type variables
+	      -> Maybe CType
 	      -> ThetaType	       -- ^ Stupid theta
 	      -> AlgTyConRhs
 	      -> RecFlag
@@ -63,8 +65,8 @@ buildAlgTyCon :: Name
               -> TyConParent
 	      -> TyCon
 
-buildAlgTyCon tc_name ktvs stupid_theta rhs is_rec gadt_syn parent
-  = mkAlgTyCon tc_name kind ktvs stupid_theta rhs parent is_rec gadt_syn
+buildAlgTyCon tc_name ktvs cType stupid_theta rhs is_rec gadt_syn parent
+  = mkAlgTyCon tc_name kind ktvs cType stupid_theta rhs parent is_rec gadt_syn
   where 
     kind = mkPiKinds ktvs liftedTypeKind
 
diff --git a/compiler/iface/FlagChecker.hs b/compiler/iface/FlagChecker.hs
index 5e4a7092bf..0365be7338 100644
--- a/compiler/iface/FlagChecker.hs
+++ b/compiler/iface/FlagChecker.hs
@@ -10,6 +10,7 @@ import Binary
 import BinIface ()
 import DynFlags
 import HscTypes
+import Module
 import Name
 import Fingerprint
 -- import Outputable
@@ -21,11 +22,12 @@ import System.FilePath (normalise)
 -- | Produce a fingerprint of a @DynFlags@ value. We only base
 -- the finger print on important fields in @DynFlags@ so that
 -- the recompilation checker can use this fingerprint.
-fingerprintDynFlags :: DynFlags -> (BinHandle -> Name -> IO ())
+fingerprintDynFlags :: DynFlags -> Module -> (BinHandle -> Name -> IO ())
                     -> IO Fingerprint
 
-fingerprintDynFlags DynFlags{..} nameio =
-    let mainis   = (mainModIs, mainFunIs)
+fingerprintDynFlags DynFlags{..} this_mod nameio =
+    let mainis   = if mainModIs == this_mod then Just mainFunIs else Nothing
+                      -- see #5878
         -- pkgopts  = (thisPackage dflags, sort $ packageFlags dflags)
         safeHs   = setSafeMode safeHaskell
         -- oflags   = sort $ filter filterOFlags $ flags dflags
@@ -38,12 +40,8 @@ fingerprintDynFlags DynFlags{..} nameio =
         cpp = (map normalise includePaths, sOpt_P settings)
             -- normalise: eliminate spurious differences due to "./foo" vs "foo"
 
-        -- -i, -osuf, -hcsuf, -hisuf, -odir, -hidir, -stubdir, -o, -ohi
-        paths = (map normalise importPaths,
-                   [ objectSuf, hcSuf, hiSuf ],
-                   [ objectDir, hiDir, stubDir, outputHi ])
-                   -- NB. not outputFile, we don't want "ghc --make M -o <file>"
-                   -- to force recompilation when <file> changes.
+        -- Note [path flags and recompilation]
+        paths = [ hcSuf ]
 
         -- -fprof-auto etc.
         prof = if opt_SccProfilingOn then fromEnum profAuto else 0
@@ -51,3 +49,33 @@ fingerprintDynFlags DynFlags{..} nameio =
     in -- pprTrace "flags" (ppr (mainis, safeHs, lang, cpp, paths)) $
        computeFingerprint nameio (mainis, safeHs, lang, cpp, paths, prof)
 
+
+{- Note [path flags and recompilation]
+
+There are several flags that we deliberately omit from the
+recompilation check; here we explain why.
+
+-osuf, -odir, -hisuf, -hidir
+  If GHC decides that it does not need to recompile, then
+  it must have found an up-to-date .hi file and .o file.
+  There is no point recording these flags - the user must
+  have passed the correct ones.  Indeed, the user may
+  have compiled the source file in one-shot mode using
+  -o to specify the .o file, and then loaded it in GHCi
+  using -odir.
+
+-stubdir
+  We omit this one because it is automatically set by -outputdir, and
+  we don't want changes in -outputdir to automatically trigger
+  recompilation.  This could be wrong, but only in very rare cases.
+
+-i (importPaths)
+  For the same reason as -osuf etc. above: if GHC decides not to
+  recompile, then it must have already checked all the .hi files on
+  which the current module depends, so it must have found them
+  successfully.  It is occasionally useful to be able to cd to a
+  different directory and use -i flags to enable GHC to find the .hi
+  files; we don't want this to force recompilation.
+
+The only path-related flag left is -hcsuf.
+-}
diff --git a/compiler/iface/IfaceSyn.lhs b/compiler/iface/IfaceSyn.lhs
index ef74b13489..d3e44fe54f 100644
--- a/compiler/iface/IfaceSyn.lhs
+++ b/compiler/iface/IfaceSyn.lhs
@@ -68,6 +68,7 @@ data IfaceDecl
               ifIdInfo    :: IfaceIdInfo }
 
   | IfaceData { ifName       :: OccName,        -- Type constructor
+                ifCType      :: Maybe CType,    -- C type for CAPI FFI
                 ifTyVars     :: [IfaceTvBndr],  -- Type variables
                 ifCtxt       :: IfaceContext,   -- The "stupid theta"
                 ifCons       :: IfaceConDecls,  -- Includes new/data/data family info
@@ -453,7 +454,8 @@ pprIfaceDecl (IfaceId {ifName = var, ifType = ty,
 pprIfaceDecl (IfaceForeign {ifName = tycon})
   = hsep [ptext (sLit "foreign import type dotnet"), ppr tycon]
 
-pprIfaceDecl (IfaceSyn {ifName = tycon, ifTyVars = tyvars,
+pprIfaceDecl (IfaceSyn {ifName = tycon,
+                        ifTyVars = tyvars,
                         ifSynRhs = Just mono_ty})
   = hang (ptext (sLit "type") <+> pprIfaceDeclHead [] tycon tyvars)
        4 (vcat [equals <+> ppr mono_ty])
@@ -463,11 +465,12 @@ pprIfaceDecl (IfaceSyn {ifName = tycon, ifTyVars = tyvars,
   = hang (ptext (sLit "type family") <+> pprIfaceDeclHead [] tycon tyvars)
        4 (dcolon <+> ppr kind)
 
-pprIfaceDecl (IfaceData {ifName = tycon, ifCtxt = context,
+pprIfaceDecl (IfaceData {ifName = tycon, ifCType = cType,
+                         ifCtxt = context,
                          ifTyVars = tyvars, ifCons = condecls,
                          ifRec = isrec, ifAxiom = mbAxiom})
   = hang (pp_nd <+> pprIfaceDeclHead context tycon tyvars)
-       4 (vcat [pprRec isrec, pp_condecls tycon condecls,
+       4 (vcat [pprCType cType, pprRec isrec, pp_condecls tycon condecls,
                 pprAxiom mbAxiom])
   where
     pp_nd = case condecls of
@@ -489,6 +492,10 @@ pprIfaceDecl (IfaceAxiom {ifName = name, ifTyVars = tyvars,
   = hang (ptext (sLit "axiom") <+> ppr name <+> ppr tyvars)
        2 (dcolon <+> ppr lhs <+> text "~#" <+> ppr rhs)
 
+pprCType :: Maybe CType -> SDoc
+pprCType Nothing = ptext (sLit "No C type associated")
+pprCType (Just cType) = ptext (sLit "C type:") <+> ppr cType
+
 pprRec :: RecFlag -> SDoc
 pprRec isrec = ptext (sLit "RecFlag") <+> ppr isrec
 
@@ -876,7 +883,6 @@ freeNamesIfExpr _ = emptyNameSet
 freeNamesIfTc :: IfaceTyCon -> NameSet
 freeNamesIfTc (IfaceTc tc) = unitNameSet tc
 -- ToDo: shouldn't we include IfaceIntTc & co.?
-freeNamesIfTc _ = emptyNameSet
 
 freeNamesIfCo :: IfaceCoCon -> NameSet
 freeNamesIfCo (IfaceCoAx tc) = unitNameSet tc
diff --git a/compiler/iface/IfaceType.lhs b/compiler/iface/IfaceType.lhs
index 77f4b700d2..a833d2c218 100644
--- a/compiler/iface/IfaceType.lhs
+++ b/compiler/iface/IfaceType.lhs
@@ -19,7 +19,6 @@ module IfaceType (
         IfaceType(..), IfacePredType, IfaceKind, IfaceTyCon(..), IfaceCoCon(..),
         IfaceTyLit(..),
 	IfaceContext, IfaceBndr(..), IfaceTvBndr, IfaceIdBndr, IfaceCoercion,
-	ifaceTyConName,
 
 	-- Conversion from Type -> IfaceType
         toIfaceType, toIfaceKind, toIfaceContext,
@@ -93,20 +92,9 @@ data IfaceTyLit
   = IfaceNumTyLit Integer
   | IfaceStrTyLit FastString
 
-data IfaceTyCon 	-- Encodes type constructors, kind constructors
-     			-- coercion constructors, the lot
-  = IfaceTc IfExtName	-- The common case
-  | IfaceIntTc | IfaceBoolTc | IfaceCharTc
-  | IfaceListTc | IfacePArrTc
-  | IfaceTupTc TupleSort Arity 
-  | IfaceIPTc IfIPName       -- Used for implicit parameter TyCons
-
-  -- Kind constructors
-  | IfaceLiftedTypeKindTc | IfaceOpenTypeKindTc | IfaceUnliftedTypeKindTc
-  | IfaceUbxTupleKindTc | IfaceArgTypeKindTc | IfaceConstraintKindTc
-
-  -- SuperKind constructor
-  | IfaceSuperKindTc  -- IA0_NOTE: You might want to check if I didn't forget something.
+-- Encodes type constructors, kind constructors
+-- coercion constructors, the lot
+newtype IfaceTyCon = IfaceTc { ifaceTyConName :: IfExtName }
 
   -- Coercion constructors
 data IfaceCoCon
@@ -115,40 +103,8 @@ data IfaceCoCon
   | IfaceReflCo    | IfaceUnsafeCo  | IfaceSymCo
   | IfaceTransCo   | IfaceInstCo
   | IfaceNthCo Int
-
-ifaceTyConName :: IfaceTyCon -> Name
-ifaceTyConName IfaceIntTc              = intTyConName
-ifaceTyConName IfaceBoolTc 	       = boolTyConName
-ifaceTyConName IfaceCharTc 	       = charTyConName
-ifaceTyConName IfaceListTc 	       = listTyConName
-ifaceTyConName IfacePArrTc 	       = parrTyConName
-ifaceTyConName (IfaceTupTc bx ar)      = getName (tupleTyCon bx ar)
-ifaceTyConName IfaceLiftedTypeKindTc   = liftedTypeKindTyConName
-ifaceTyConName IfaceOpenTypeKindTc     = openTypeKindTyConName
-ifaceTyConName IfaceUnliftedTypeKindTc = unliftedTypeKindTyConName
-ifaceTyConName IfaceUbxTupleKindTc     = ubxTupleKindTyConName
-ifaceTyConName IfaceArgTypeKindTc      = argTypeKindTyConName
-ifaceTyConName IfaceConstraintKindTc   = constraintKindTyConName
-ifaceTyConName IfaceSuperKindTc        = tySuperKindTyConName
-ifaceTyConName (IfaceTc ext)           = ext
-ifaceTyConName (IfaceIPTc n)           = pprPanic "ifaceTyConName:IPTc" (ppr n)
-	       		    	       	 -- Note [The Name of an IfaceAnyTc]
 \end{code}
 
-Note [The Name of an IfaceAnyTc]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-IA0_NOTE: This is an old comment. It needs to be updated with IPTc which
-I don't know about.
-
-It isn't easy to get the Name of an IfaceAnyTc in a pure way.  What you
-really need to do is to transform it to a TyCon, and get the Name of that.
-But doing so needs the monad because there's an IfaceKind inside, and we
-need a Kind.
-
-In fact, ifaceTyConName is only used for instances and rules, and we don't
-expect to instantiate those at these (internal-ish) Any types, so rather
-than solve this potential problem now, I'm going to defer it until it happens!
-
 %************************************************************************
 %*									*
 		Functions over IFaceTypes
@@ -220,9 +176,10 @@ pprIfaceIdBndr :: (IfLclName, IfaceType) -> SDoc
 pprIfaceIdBndr (name, ty) = hsep [ppr name, dcolon, ppr ty]
 
 pprIfaceTvBndr :: IfaceTvBndr -> SDoc
-pprIfaceTvBndr (tv, IfaceTyConApp IfaceLiftedTypeKindTc [])
-  = ppr tv
+pprIfaceTvBndr (tv, IfaceTyConApp tc [])
+  | ifaceTyConName tc == liftedTypeKindTyConName = ppr tv
 pprIfaceTvBndr (tv, kind) = parens (ppr tv <> dcolon <> ppr kind)
+
 pprIfaceTvBndrs :: [IfaceTvBndr] -> SDoc
 pprIfaceTvBndrs tyvars = hsep (map pprIfaceTvBndr tyvars)
 \end{code}
@@ -288,27 +245,25 @@ pprIfaceForAllPart tvs ctxt doc
 ppr_tc_app :: Int -> IfaceTyCon -> [IfaceType] -> SDoc
 ppr_tc_app _         tc          []   = ppr_tc tc
 
-ppr_tc_app _         IfaceListTc [ty] = brackets (pprIfaceType ty)
-ppr_tc_app _         IfaceListTc _    = panic "ppr_tc_app IfaceListTc"
-
-ppr_tc_app _         IfacePArrTc [ty] = pabrackets (pprIfaceType ty)
-ppr_tc_app _         IfacePArrTc _    = panic "ppr_tc_app IfacePArrTc"
-
-ppr_tc_app _         (IfaceTupTc sort _) tys =
-  tupleParens sort (sep (punctuate comma (map pprIfaceType tys)))
-
-ppr_tc_app _         (IfaceIPTc n) [ty] =
-  parens (ppr n <> dcolon <> pprIfaceType ty)
-ppr_tc_app _         (IfaceIPTc _) _ = panic "ppr_tc_app IfaceIPTc"
 
+ppr_tc_app _         (IfaceTc n) [ty] | n == listTyConName = brackets (pprIfaceType ty)
+ppr_tc_app _         (IfaceTc n) [ty] | n == parrTyConName = paBrackets (pprIfaceType ty)
+ppr_tc_app _         (IfaceTc n) tys
+  | Just (ATyCon tc) <- wiredInNameTyThing_maybe n
+  , Just sort <- tyConTuple_maybe tc
+  , tyConArity tc == length tys 
+  = tupleParens sort (sep (punctuate comma (map pprIfaceType tys)))
+  | Just (ATyCon tc) <- wiredInNameTyThing_maybe n
+  , Just ip <- tyConIP_maybe tc
+  , [ty] <- tys
+  = parens (ppr ip <> dcolon <> pprIfaceType ty)
 ppr_tc_app ctxt_prec tc tys
-  = maybeParen ctxt_prec tYCON_PREC 
+  = maybeParen ctxt_prec tYCON_PREC
                (sep [ppr_tc tc, nest 4 (sep (map pprParendIfaceType tys))])
 
 ppr_tc :: IfaceTyCon -> SDoc
 -- Wrap infix type constructors in parens
-ppr_tc tc@(IfaceTc ext_nm) = parenSymOcc (getOccName ext_nm) (ppr tc)
-ppr_tc tc		   = ppr tc
+ppr_tc tc = parenSymOcc (getOccName (ifaceTyConName tc)) (ppr tc)
 
 ppr_tylit :: IfaceTyLit -> SDoc
 ppr_tylit (IfaceNumTyLit n) = integer n
@@ -316,8 +271,7 @@ ppr_tylit (IfaceStrTyLit n) = text (show n)
 
 -------------------
 instance Outputable IfaceTyCon where
-  ppr (IfaceIPTc n)  = ppr (IPName n)
-  ppr other_tc       = ppr (ifaceTyConName other_tc)
+  ppr = ppr . ifaceTyConName
 
 instance Outputable IfaceCoCon where
   ppr (IfaceCoAx n)    = ppr n
@@ -341,10 +295,6 @@ pprIfaceContext theta = ppr_preds theta <+> darrow
 ppr_preds :: [IfacePredType] -> SDoc
 ppr_preds [pred] = ppr pred    -- No parens
 ppr_preds preds  = parens (sep (punctuate comma (map ppr preds))) 
-
--------------------
-pabrackets :: SDoc -> SDoc
-pabrackets p = ptext (sLit "[:") <> p <> ptext (sLit ":]")
 \end{code}
 
 %************************************************************************
@@ -388,35 +338,10 @@ toIfaceCoVar = occNameFS . getOccName
 
 ----------------
 toIfaceTyCon :: TyCon -> IfaceTyCon
-toIfaceTyCon tc 
-  | isTupleTyCon tc            = IfaceTupTc (tupleTyConSort tc) (tyConArity tc)
-  | Just n <- tyConIP_maybe tc = IfaceIPTc (ipFastString n)
-  | otherwise	               = toIfaceTyCon_name (tyConName tc)
+toIfaceTyCon = toIfaceTyCon_name . tyConName
 
 toIfaceTyCon_name :: Name -> IfaceTyCon
-toIfaceTyCon_name nm
-  | Just (ATyCon tc) <- wiredInNameTyThing_maybe nm
-  = toIfaceWiredInTyCon tc nm
-  | otherwise
-  = IfaceTc nm
-
-toIfaceWiredInTyCon :: TyCon -> Name -> IfaceTyCon
-toIfaceWiredInTyCon tc nm
-  | isTupleTyCon tc                 = IfaceTupTc  (tupleTyConSort tc) (tyConArity tc)
-  | Just n <- tyConIP_maybe tc      = IfaceIPTc (ipFastString n)
-  | nm == intTyConName              = IfaceIntTc
-  | nm == boolTyConName             = IfaceBoolTc 
-  | nm == charTyConName             = IfaceCharTc 
-  | nm == listTyConName             = IfaceListTc 
-  | nm == parrTyConName             = IfacePArrTc 
-  | nm == liftedTypeKindTyConName   = IfaceLiftedTypeKindTc
-  | nm == unliftedTypeKindTyConName = IfaceUnliftedTypeKindTc
-  | nm == openTypeKindTyConName     = IfaceOpenTypeKindTc
-  | nm == argTypeKindTyConName      = IfaceArgTypeKindTc
-  | nm == constraintKindTyConName   = IfaceConstraintKindTc
-  | nm == ubxTupleKindTyConName     = IfaceUbxTupleKindTc
-  | nm == tySuperKindTyConName      = IfaceSuperKindTc
-  | otherwise		            = IfaceTc nm
+toIfaceTyCon_name = IfaceTc
 
 toIfaceTyLit :: TyLit -> IfaceTyLit
 toIfaceTyLit (NumTyLit x) = IfaceNumTyLit x
diff --git a/compiler/iface/MkIface.lhs b/compiler/iface/MkIface.lhs
index 9904042fe0..877de44330 100644
--- a/compiler/iface/MkIface.lhs
+++ b/compiler/iface/MkIface.lhs
@@ -19,6 +19,7 @@ module MkIface (
 
         checkOldIface,  -- See if recompilation is required, by
                         -- comparing version information
+        RecompileRequired(..), recompileRequired,
 
         tyThingToIfaceDecl -- Converting things to their Iface equivalents
  ) where
@@ -110,6 +111,7 @@ import Data.List
 import Data.Map (Map)
 import qualified Data.Map as Map
 import Data.IORef
+import System.Directory
 import System.FilePath
 \end{code}
 
@@ -287,7 +289,7 @@ mkIface_ hsc_env maybe_old_fingerprint
                         mi_fixities    = fixities,
                         mi_warns       = warns,
                         mi_anns        = mkIfaceAnnotations anns,
-                        mi_globals     = Just rdr_env,
+                        mi_globals     = maybeGlobalRdrEnv rdr_env,
 
                         -- Left out deliberately: filled in by addFingerprints
                         mi_iface_hash  = fingerprint0,
@@ -344,7 +346,7 @@ mkIface_ hsc_env maybe_old_fingerprint
                 -- correctly.  This stems from the fact that the interface had
                 -- not changed, so addFingerprints returns the old ModIface
                 -- with the old GlobalRdrEnv (mi_globals).
-        ; let final_iface = new_iface{ mi_globals = Just rdr_env }
+        ; let final_iface = new_iface{ mi_globals = maybeGlobalRdrEnv rdr_env }
 
         ; return (errs_and_warns, Just (final_iface, no_change_at_all)) }}
   where
@@ -359,6 +361,17 @@ mkIface_ hsc_env maybe_old_fingerprint
 
      dflags = hsc_dflags hsc_env
 
+     -- We only fill in mi_globals if the module was compiled to byte
+     -- code.  Otherwise, the compiler may not have retained all the
+     -- top-level bindings and they won't be in the TypeEnv (see
+     -- Desugar.addExportFlagsAndRules).  The mi_globals field is used
+     -- by GHCi to decide whether the module has its full top-level
+     -- scope available. (#5534)
+     maybeGlobalRdrEnv :: GlobalRdrEnv -> Maybe GlobalRdrEnv
+     maybeGlobalRdrEnv rdr_env
+         | targetRetainsAllBindings (hscTarget dflags) = Just rdr_env
+         | otherwise                                   = Nothing
+
      deliberatelyOmitted :: String -> a
      deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
 
@@ -380,7 +393,7 @@ mkIface_ hsc_env maybe_old_fingerprint
 -----------------------------
 writeIfaceFile :: DynFlags -> ModLocation -> ModIface -> IO ()
 writeIfaceFile dflags location new_iface
-    = do createDirectoryHierarchy (takeDirectory hi_file_path)
+    = do createDirectoryIfMissing True (takeDirectory hi_file_path)
          writeBinIface dflags hi_file_path new_iface
     where hi_file_path = ml_hi_file location
 
@@ -583,7 +596,7 @@ addFingerprints hsc_env mb_old_fingerprint iface0 new_decls
    --   - (some of) dflags
    -- it returns two hashes, one that shouldn't change
    -- the abi hash and one that should
-   flag_hash <- fingerprintDynFlags dflags putNameLiterally
+   flag_hash <- fingerprintDynFlags dflags this_mod putNameLiterally
 
    -- the ABI hash depends on:
    --   - decls
@@ -1073,11 +1086,28 @@ Trac #5362 for an example.  Such Names are always
 %*                                                                      *
         Load the old interface file for this module (unless
         we have it already), and check whether it is up to date
-        
 %*                                                                      *
 %************************************************************************
 
 \begin{code}
+data RecompileRequired
+  = UpToDate
+       -- ^ everything is up to date, recompilation is not required
+  | MustCompile
+       -- ^ The .hs file has been touched, or the .o/.hi file does not exist
+  | RecompBecause String
+       -- ^ The .o/.hi files are up to date, but something else has changed
+       -- to force recompilation; the String says what (one-line summary)
+  | RecompForcedByTH
+       -- ^ recompile is forced due to use of TH by the module
+   deriving Eq
+
+recompileRequired :: RecompileRequired -> Bool
+recompileRequired UpToDate = False
+recompileRequired _ = True
+
+
+
 -- | Top level function to check if the version of an old interface file
 -- is equivalent to the current source file the user asked us to compile.
 -- If the same, we can avoid recompilation. We return a tuple where the
@@ -1097,7 +1127,7 @@ checkOldIface hsc_env mod_summary source_modified maybe_iface
             check_old_iface hsc_env mod_summary source_modified maybe_iface
 
 check_old_iface :: HscEnv -> ModSummary -> SourceModified -> Maybe ModIface
-                -> IfG (Bool, Maybe ModIface)
+                -> IfG (RecompileRequired, Maybe ModIface)
 check_old_iface hsc_env mod_summary src_modified maybe_iface
   = let dflags = hsc_dflags hsc_env
         getIface =
@@ -1131,19 +1161,19 @@ check_old_iface hsc_env mod_summary src_modified maybe_iface
             -- avoid reading an interface; just return the one we might
             -- have been supplied with.
             True | not (isObjectTarget $ hscTarget dflags) ->
-                return (outOfDate, maybe_iface)
+                return (MustCompile, maybe_iface)
 
             -- Try and read the old interface for the current module
             -- from the .hi file left from the last time we compiled it
             True -> do
                 maybe_iface' <- getIface
-                return (outOfDate, maybe_iface')
+                return (MustCompile, maybe_iface')
 
             False -> do
                 maybe_iface' <- getIface
                 case maybe_iface' of
                     -- We can't retrieve the iface
-                    Nothing    -> return (outOfDate, Nothing)
+                    Nothing    -> return (MustCompile, Nothing)
 
                     -- We have got the old iface; check its versions
                     -- even in the SourceUnmodifiedAndStable case we
@@ -1151,15 +1181,6 @@ check_old_iface hsc_env mod_summary src_modified maybe_iface
                     -- might have changed or gone away.
                     Just iface -> checkVersions hsc_env mod_summary iface
 
--- | @recompileRequired@ is called from the HscMain.   It checks whether
--- a recompilation is required.  It needs access to the persistent state,
--- finder, etc, because it may have to load lots of interface files to
--- check their versions.
-type RecompileRequired = Bool
-upToDate, outOfDate :: Bool
-upToDate  = False  -- Recompile not required
-outOfDate = True   -- Recompile required
-
 -- | Check if a module is still the same 'version'.
 --
 -- This function is called in the recompilation checker after we have
@@ -1180,9 +1201,9 @@ checkVersions hsc_env mod_summary iface
                         ppr (mi_module iface) <> colon)
 
        ; recomp <- checkFlagHash hsc_env iface
-       ; if recomp then return (outOfDate, Nothing) else do {
+       ; if recompileRequired recomp then return (recomp, Nothing) else do {
        ; recomp <- checkDependencies hsc_env mod_summary iface
-       ; if recomp then return (outOfDate, Just iface) else do {
+       ; if recompileRequired recomp then return (recomp, Just iface) else do {
 
        -- Source code unchanged and no errors yet... carry on
        --
@@ -1211,10 +1232,13 @@ checkVersions hsc_env mod_summary iface
 checkFlagHash :: HscEnv -> ModIface -> IfG RecompileRequired
 checkFlagHash hsc_env iface = do
     let old_hash = mi_flag_hash iface
-    new_hash <- liftIO $ fingerprintDynFlags (hsc_dflags hsc_env) putNameLiterally
+    new_hash <- liftIO $ fingerprintDynFlags (hsc_dflags hsc_env)
+                                             (mi_module iface)
+                                             putNameLiterally
     case old_hash == new_hash of
         True  -> up_to_date (ptext $ sLit "Module flags unchanged")
-        False -> out_of_date_hash (ptext $ sLit "  Module flags have changed")
+        False -> out_of_date_hash "flags changed"
+                     (ptext $ sLit "  Module flags have changed")
                      old_hash new_hash
 
 -- If the direct imports of this module are resolved to targets that
@@ -1229,18 +1253,16 @@ checkFlagHash hsc_env iface = do
 -- Returns True if recompilation is required.
 checkDependencies :: HscEnv -> ModSummary -> ModIface -> IfG RecompileRequired
 checkDependencies hsc_env summary iface
- = orM (map dep_missing (ms_imps summary ++ ms_srcimps summary))
+ = checkList (map dep_missing (ms_imps summary ++ ms_srcimps summary))
   where
    prev_dep_mods = dep_mods (mi_deps iface)
    prev_dep_pkgs = dep_pkgs (mi_deps iface)
 
    this_pkg = thisPackage (hsc_dflags hsc_env)
 
-   orM = foldr f (return False)
-    where f m rest = do b <- m; if b then return True else rest
-
    dep_missing (L _ (ImportDecl { ideclName = L _ mod, ideclPkgQual = pkg })) = do
      find_res <- liftIO $ findImportedModule hsc_env mod pkg
+     let reason = moduleNameString mod ++ " changed"
      case find_res of
         Found _ mod
           | pkg == this_pkg
@@ -1248,20 +1270,20 @@ checkDependencies hsc_env summary iface
                  then do traceHiDiffs $
                            text "imported module " <> quotes (ppr mod) <>
                            text " not among previous dependencies"
-                         return outOfDate
+                         return (RecompBecause reason)
                  else
-                         return upToDate
+                         return UpToDate
           | otherwise
            -> if pkg `notElem` (map fst prev_dep_pkgs)
                  then do traceHiDiffs $
                            text "imported module " <> quotes (ppr mod) <>
                            text " is from package " <> quotes (ppr pkg) <>
                            text ", which is not among previous dependencies"
-                         return outOfDate
+                         return (RecompBecause reason)
                  else
-                         return upToDate
+                         return UpToDate
            where pkg = modulePackageId mod
-        _otherwise  -> return outOfDate
+        _otherwise  -> return (RecompBecause reason)
 
 needInterface :: Module -> (ModIface -> IfG RecompileRequired)
               -> IfG RecompileRequired
@@ -1275,8 +1297,10 @@ needInterface mod continue
         -- Instead, get an Either back which we can test
 
     case mb_iface of
-      Failed _ ->  (out_of_date (sep [ptext (sLit "Couldn't load interface for module"),
-                                      ppr mod]))
+      Failed _ -> do
+        traceHiDiffs (sep [ptext (sLit "Couldn't load interface for module"),
+                           ppr mod])
+        return MustCompile
                   -- Couldn't find or parse a module mentioned in the
                   -- old interface file.  Don't complain: it might
                   -- just be that the current module doesn't need that
@@ -1292,7 +1316,8 @@ checkModUsage _this_pkg UsagePackageModule{
                                 usg_mod = mod,
                                 usg_mod_hash = old_mod_hash }
   = needInterface mod $ \iface -> do
-    checkModuleFingerprint old_mod_hash (mi_mod_hash iface)
+    let reason = moduleNameString (moduleName mod) ++ " changed"
+    checkModuleFingerprint reason old_mod_hash (mi_mod_hash iface)
         -- We only track the ABI hash of package modules, rather than
         -- individual entity usages, so if the ABI hash changes we must
         -- recompile.  This is safe but may entail more recompilation when
@@ -1312,19 +1337,21 @@ checkModUsage this_pkg UsageHomeModule{
         new_decl_hash   = mi_hash_fn     iface
         new_export_hash = mi_exp_hash    iface
 
+        reason = moduleNameString mod_name ++ " changed"
+
         -- CHECK MODULE
-    recompile <- checkModuleFingerprint old_mod_hash new_mod_hash
-    if not recompile then return upToDate else do
-                                 
+    recompile <- checkModuleFingerprint reason old_mod_hash new_mod_hash
+    if not (recompileRequired recompile) then return UpToDate else do
+
         -- CHECK EXPORT LIST
-    checkMaybeHash maybe_old_export_hash new_export_hash
+    checkMaybeHash reason maybe_old_export_hash new_export_hash
         (ptext (sLit "  Export list changed")) $ do
 
         -- CHECK ITEMS ONE BY ONE
-    recompile <- checkList [ checkEntityUsage new_decl_hash u 
+    recompile <- checkList [ checkEntityUsage reason new_decl_hash u
                            | u <- old_decl_hash]
-    if recompile 
-      then return outOfDate     -- This one failed, so just bail out now
+    if recompileRequired recompile
+      then return recompile     -- This one failed, so just bail out now
       else up_to_date (ptext (sLit "  Great!  The bits I use are up to date"))
  
 
@@ -1333,65 +1360,72 @@ checkModUsage _this_pkg UsageFile{ usg_file_path = file,
   liftIO $
     handleIO handle $ do
       new_mtime <- getModificationUTCTime file
-      return $ old_mtime /= new_mtime
+      if (old_mtime /= new_mtime)
+         then return recomp
+         else return UpToDate
  where
+   recomp = RecompBecause (file ++ " changed")
    handle =
 #ifdef DEBUG
-       \e -> pprTrace "UsageFile" (text (show e)) $ return True
+       \e -> pprTrace "UsageFile" (text (show e)) $ return recomp
 #else
-       \_ -> return True -- if we can't find the file, just recompile, don't fail
+       \_ -> return recomp -- if we can't find the file, just recompile, don't fail
 #endif
 
 ------------------------
-checkModuleFingerprint :: Fingerprint -> Fingerprint -> IfG RecompileRequired
-checkModuleFingerprint old_mod_hash new_mod_hash
+checkModuleFingerprint :: String -> Fingerprint -> Fingerprint
+                       -> IfG RecompileRequired
+checkModuleFingerprint reason old_mod_hash new_mod_hash
   | new_mod_hash == old_mod_hash
   = up_to_date (ptext (sLit "Module fingerprint unchanged"))
 
   | otherwise
-  = out_of_date_hash (ptext (sLit "  Module fingerprint has changed"))
+  = out_of_date_hash reason (ptext (sLit "  Module fingerprint has changed"))
                      old_mod_hash new_mod_hash
 
 ------------------------
-checkMaybeHash :: Maybe Fingerprint -> Fingerprint -> SDoc
+checkMaybeHash :: String -> Maybe Fingerprint -> Fingerprint -> SDoc
                -> IfG RecompileRequired -> IfG RecompileRequired
-checkMaybeHash maybe_old_hash new_hash doc continue
+checkMaybeHash reason maybe_old_hash new_hash doc continue
   | Just hash <- maybe_old_hash, hash /= new_hash
-  = out_of_date_hash doc hash new_hash
+  = out_of_date_hash reason doc hash new_hash
   | otherwise
   = continue
 
 ------------------------
-checkEntityUsage :: (OccName -> Maybe (OccName, Fingerprint))
+checkEntityUsage :: String
+                 -> (OccName -> Maybe (OccName, Fingerprint))
                  -> (OccName, Fingerprint)
                  -> IfG RecompileRequired
-checkEntityUsage new_hash (name,old_hash)
+checkEntityUsage reason new_hash (name,old_hash)
   = case new_hash name of
 
         Nothing       ->        -- We used it before, but it ain't there now
-                          out_of_date (sep [ptext (sLit "No longer exported:"), ppr name])
+                          out_of_date reason (sep [ptext (sLit "No longer exported:"), ppr name])
 
         Just (_, new_hash)      -- It's there, but is it up to date?
           | new_hash == old_hash -> do traceHiDiffs (text "  Up to date" <+> ppr name <+> parens (ppr new_hash))
-                                       return upToDate
-          | otherwise            -> out_of_date_hash (ptext (sLit "  Out of date:") <+> ppr name)
+                                       return UpToDate
+          | otherwise            -> out_of_date_hash reason (ptext (sLit "  Out of date:") <+> ppr name)
                                                      old_hash new_hash
 
-up_to_date, out_of_date :: SDoc -> IfG RecompileRequired
-up_to_date  msg = traceHiDiffs msg >> return upToDate
-out_of_date msg = traceHiDiffs msg >> return outOfDate
+up_to_date :: SDoc -> IfG RecompileRequired
+up_to_date  msg = traceHiDiffs msg >> return UpToDate
+
+out_of_date :: String -> SDoc -> IfG RecompileRequired
+out_of_date reason msg = traceHiDiffs msg >> return (RecompBecause reason)
 
-out_of_date_hash :: SDoc -> Fingerprint -> Fingerprint -> IfG RecompileRequired
-out_of_date_hash msg old_hash new_hash 
-  = out_of_date (hsep [msg, ppr old_hash, ptext (sLit "->"), ppr new_hash])
+out_of_date_hash :: String -> SDoc -> Fingerprint -> Fingerprint -> IfG RecompileRequired
+out_of_date_hash reason msg old_hash new_hash
+  = out_of_date reason (hsep [msg, ppr old_hash, ptext (sLit "->"), ppr new_hash])
 
 ----------------------
 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
 -- This helper is used in two places
-checkList []             = return upToDate
+checkList []             = return UpToDate
 checkList (check:checks) = do recompile <- check
-                              if recompile
-                                then return outOfDate
+                              if recompileRequired recompile
+                                then return recompile
                                 else checkList checks
 \end{code}
 
@@ -1425,6 +1459,7 @@ tyThingToIfaceDecl (ATyCon tycon)
 
   | isAlgTyCon tycon
   = IfaceData { ifName    = getOccName tycon,
+                ifCType   = tyConCType tycon,
                 ifTyVars  = toIfaceTvBndrs tyvars,
                 ifCtxt    = toIfaceContext (tyConStupidTheta tycon),
                 ifCons    = ifaceConDecls (algTyConRhs tycon),
diff --git a/compiler/iface/TcIface.lhs b/compiler/iface/TcIface.lhs
index a081fbe36e..e0b0f1d2a8 100644
--- a/compiler/iface/TcIface.lhs
+++ b/compiler/iface/TcIface.lhs
@@ -41,7 +41,7 @@ import TyCon
 import DataCon
 import PrelNames
 import TysWiredIn
-import TysPrim          ( tySuperKindTyCon )
+import TysPrim          ( superKindTyConName )
 import BasicTypes       ( Arity, strongLoopBreaker )
 import Literal
 import qualified Var
@@ -432,6 +432,7 @@ tc_iface_decl _ ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type,
         ; return (AnId (mkGlobalId details name ty info)) }
 
 tc_iface_decl parent _ (IfaceData {ifName = occ_name, 
+                          ifCType = cType, 
                           ifTyVars = tv_bndrs, 
                           ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
                           ifCons = rdr_cons, 
@@ -443,7 +444,7 @@ tc_iface_decl parent _ (IfaceData {ifName = occ_name,
             { stupid_theta <- tcIfaceCtxt ctxt
             ; parent' <- tc_parent tyvars mb_axiom_name
             ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
-            ; return (buildAlgTyCon tc_name tyvars stupid_theta 
+            ; return (buildAlgTyCon tc_name tyvars cType stupid_theta 
                                     cons is_rec gadt_syn parent') }
     ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
     ; return (ATyCon tycon) }
@@ -1242,6 +1243,9 @@ tcIfaceGlobal :: Name -> IfL TyThing
 tcIfaceGlobal name
   | Just thing <- wiredInNameTyThing_maybe name
         -- Wired-in things include TyCons, DataCons, and Ids
+        -- Even though we are in an interface file, we want to make
+        -- sure the instances and RULES of this thing (particularly TyCon) are loaded 
+        -- Imagine: f :: Double -> Double
   = do { ifCheckWiredInThing thing; return thing }
   | otherwise
   = do  { env <- getGblEnv
@@ -1286,37 +1290,13 @@ tcIfaceGlobal name
 -- emasculated form (e.g. lacking data constructors).
 
 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
-tcIfaceTyCon IfaceIntTc         = tcWiredInTyCon intTyCon
-tcIfaceTyCon IfaceBoolTc        = tcWiredInTyCon boolTyCon
-tcIfaceTyCon IfaceCharTc        = tcWiredInTyCon charTyCon
-tcIfaceTyCon IfaceListTc        = tcWiredInTyCon listTyCon
-tcIfaceTyCon IfacePArrTc        = tcWiredInTyCon parrTyCon
-tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
-tcIfaceTyCon (IfaceIPTc n)      = do { n' <- newIPName n
-                                     ; tcWiredInTyCon (ipTyCon n') }
-tcIfaceTyCon (IfaceTc name)     = do { thing <- tcIfaceGlobal name
-                                     ; return (check_tc (tyThingTyCon thing)) }
-  where
-    check_tc tc
-     | debugIsOn = case toIfaceTyCon tc of
-                   IfaceTc _ -> tc
-                   _         -> pprTrace "check_tc" (ppr tc) tc
-     | otherwise = tc
--- we should be okay just returning Kind constructors without extra loading
-tcIfaceTyCon IfaceLiftedTypeKindTc   = return liftedTypeKindTyCon
-tcIfaceTyCon IfaceOpenTypeKindTc     = return openTypeKindTyCon
-tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
-tcIfaceTyCon IfaceArgTypeKindTc      = return argTypeKindTyCon
-tcIfaceTyCon IfaceUbxTupleKindTc     = return ubxTupleKindTyCon
-tcIfaceTyCon IfaceConstraintKindTc   = return constraintKindTyCon
-tcIfaceTyCon IfaceSuperKindTc        = return tySuperKindTyCon
-
--- Even though we are in an interface file, we want to make
--- sure the instances and RULES of this tycon are loaded 
--- Imagine: f :: Double -> Double
-tcWiredInTyCon :: TyCon -> IfL TyCon
-tcWiredInTyCon tc = do { ifCheckWiredInThing (ATyCon tc)
-                       ; return tc }
+tcIfaceTyCon (IfaceTc name) 
+  = do { thing <- tcIfaceGlobal name
+       ; case thing of    -- A "type constructor" can be a promoted data constructor
+                          --           c.f. Trac #5881
+           ATyCon   tc -> return tc
+           ADataCon dc -> return (buildPromotedDataCon dc)
+           _ -> pprPanic "tcIfaceTyCon" (ppr name $$ ppr thing) }
 
 tcIfaceCoAxiom :: Name -> IfL CoAxiom
 tcIfaceCoAxiom name = do { thing <- tcIfaceGlobal name
@@ -1388,7 +1368,7 @@ bindIfaceTyVars bndrs thing_inside
     (occs,kinds) = unzip bndrs
 
 isSuperIfaceKind :: IfaceKind -> Bool
-isSuperIfaceKind (IfaceTyConApp IfaceSuperKindTc []) = True
+isSuperIfaceKind (IfaceTyConApp (IfaceTc n) []) = n == superKindTyConName
 isSuperIfaceKind _ = False
 
 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar