Fix Trac #2412: type synonyms and hs-boot recursion

[ghc-hetmet.git] / compiler / iface / TcIface.lhs

diff --git a/compiler/iface/TcIface.lhs b/compiler/iface/TcIface.lhs
index f352faf..32735a4 100644 (file)
--- a/compiler/iface/TcIface.lhs
+++ b/compiler/iface/TcIface.lhs
@@ -6,13 +6,6 @@
 Type checking of type signatures in interface files
 
 \begin{code}
 Type checking of type signatures in interface files
 
 \begin{code}

-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-

 module TcIface ( 
        tcImportDecl, checkWiredInTyCon, tcHiBootIface, typecheckIface, 
        tcIfaceDecl, tcIfaceInst, tcIfaceFamInst, tcIfaceRules,
 module TcIface ( 
        tcImportDecl, checkWiredInTyCon, tcHiBootIface, typecheckIface, 
        tcIfaceDecl, tcIfaceInst, tcIfaceFamInst, tcIfaceRules,

@@ -57,8 +50,11 @@ import ErrUtils
 import Maybes
 import SrcLoc
 import DynFlags
 import Maybes
 import SrcLoc
 import DynFlags

-import Control.Monad
+import Util
+import FastString
+import BasicTypes (Arity)

 
 

+import Control.Monad

 import Data.List
 import Data.Maybe
 \end{code}
 import Data.List
 import Data.Maybe
 \end{code}

@@ -72,7 +68,7 @@ This module takes
 An IfaceDecl is populated with RdrNames, and these are not renamed to
 Names before typechecking, because there should be no scope errors etc.
 
 An IfaceDecl is populated with RdrNames, and these are not renamed to
 Names before typechecking, because there should be no scope errors etc.
 

-       -- For (b) consider: f = $(...h....)
+       -- For (b) consider: f = \$(...h....)

        -- where h is imported, and calls f via an hi-boot file.  
        -- This is bad!  But it is not seen as a staging error, because h
        -- is indeed imported.  We don't want the type-checker to black-hole 
        -- where h is imported, and calls f via an hi-boot file.  
        -- This is bad!  But it is not seen as a staging error, because h
        -- is indeed imported.  We don't want the type-checker to black-hole 

@@ -151,7 +147,7 @@ importDecl name
        ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
        ; case mb_iface of {
                Failed err_msg  -> return (Failed err_msg) ;
        ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
        ; case mb_iface of {
                Failed err_msg  -> return (Failed err_msg) ;

-               Succeeded iface -> do
+               Succeeded _ -> do

 
        -- Now look it up again; this time we should find it
        { eps <- getEps 
 
        -- Now look it up again; this time we should find it
        { eps <- getEps 

@@ -160,11 +156,11 @@ importDecl name
            Nothing    -> return (Failed not_found_msg)
     }}}
   where
            Nothing    -> return (Failed not_found_msg)
     }}}
   where

-    nd_doc = ptext SLIT("Need decl for") <+> ppr name
-    not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+>
+    nd_doc = ptext (sLit "Need decl for") <+> ppr name
+    not_found_msg = hang (ptext (sLit "Can't find interface-file declaration for") <+>

                                pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
                                pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)

-                      2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
-                               ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
+                      2 (vcat [ptext (sLit "Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
+                               ptext (sLit "Use -ddump-if-trace to get an idea of which file caused the error")])

 \end{code}
 
 %************************************************************************
 \end{code}
 
 %************************************************************************

@@ -262,7 +258,7 @@ tcHiBootIface hsc_src mod
                  ; case lookupUFM hpt (moduleName mod) of
                      Just info | mi_boot (hm_iface info) 
                                -> return (hm_details info)
                  ; case lookupUFM hpt (moduleName mod) of
                      Just info | mi_boot (hm_iface info) 
                                -> return (hm_details info)

-                     other -> return emptyModDetails }
+                     _ -> return emptyModDetails }

          else do
 
        -- OK, so we're in one-shot mode.  
          else do
 
        -- OK, so we're in one-shot mode.  

@@ -288,13 +284,13 @@ tcHiBootIface hsc_src mod
                Succeeded (iface, _path) -> typecheckIface iface
     }}}}
   where
                Succeeded (iface, _path) -> typecheckIface iface
     }}}}
   where

-    need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
-                <+> ptext SLIT("to compare against the Real Thing")
+    need = ptext (sLit "Need the hi-boot interface for") <+> ppr mod
+                <+> ptext (sLit "to compare against the Real Thing")

 
 

-    moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod) 
-                    <+> ptext SLIT("depends on itself")
+    moduleLoop = ptext (sLit "Circular imports: module") <+> quotes (ppr mod) 
+                    <+> ptext (sLit "depends on itself")

 
 

-    elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+> 
+    elaborate err = hang (ptext (sLit "Could not find hi-boot interface for") <+> 

                          quotes (ppr mod) <> colon) 4 err
 \end{code}
 
                          quotes (ppr mod) <> colon) 4 err
 \end{code}
 

@@ -358,16 +354,15 @@ tcIfaceDecl ignore_prags (IfaceId {ifName = occ_name, ifType = iface_type, ifIdI
   = do { name <- lookupIfaceTop occ_name
        ; ty <- tcIfaceType iface_type
        ; info <- tcIdInfo ignore_prags name ty info
   = do { name <- lookupIfaceTop occ_name
        ; ty <- tcIfaceType iface_type
        ; info <- tcIdInfo ignore_prags name ty info

-       ; return (AnId (mkVanillaGlobal name ty info)) }
-
-tcIfaceDecl ignore_prags 
-           (IfaceData {ifName = occ_name, 
-                       ifTyVars = tv_bndrs, 
-                       ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
-                       ifCons = rdr_cons, 
-                       ifRec = is_rec, 
-                       ifGeneric = want_generic,
-                       ifFamInst = mb_family })
+       ; return (AnId (mkVanillaGlobalWithInfo name ty info)) }
+
+tcIfaceDecl _ (IfaceData {ifName = occ_name, 
+                         ifTyVars = tv_bndrs, 
+                         ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
+                         ifCons = rdr_cons, 
+                         ifRec = is_rec, 
+                         ifGeneric = want_generic,
+                         ifFamInst = mb_family })

   = do { tc_name <- lookupIfaceTop occ_name
        ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
 
   = do { tc_name <- lookupIfaceTop occ_name
        ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
 

@@ -389,25 +384,30 @@ tcIfaceDecl ignore_prags
        ; return (ATyCon tycon)
     }}
 
        ; return (ATyCon tycon)
     }}
 

-tcIfaceDecl ignore_prags 
-           (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs, 
-                      ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty,
-                      ifFamInst = mb_family})
+tcIfaceDecl _ (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs, 
+                        ifSynRhs = mb_rhs_ty,
+                        ifSynKind = kind, ifFamInst = mb_family})

    = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
      { tc_name <- lookupIfaceTop occ_name
    = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
      { tc_name <- lookupIfaceTop occ_name

-     ; rhs_tyki <- tcIfaceType rdr_rhs_ty
-     ; let rhs = if isOpen then OpenSynTyCon rhs_tyki Nothing
-                          else SynonymTyCon rhs_tyki
-     ; famInst <- case mb_family of
-                   Nothing         -> return Nothing
-                   Just (fam, tys) -> 
-                     do { famTyCon <- tcIfaceTyCon fam
-                        ; insttys <- mapM tcIfaceType tys
-                        ; return $ Just (famTyCon, insttys)
-                        }
-     ; tycon <- buildSynTyCon tc_name tyvars rhs famInst
+     ; rhs_kind <- tcIfaceType kind    -- Note [Synonym kind loop]
+     ; ~(rhs, fam) <- forkM (mk_doc tc_name) $ 
+                             do { rhs <- tc_syn_rhs rhs_kind mb_rhs_ty
+                        ; fam <- tc_syn_fam mb_family
+                        ; return (rhs, fam) }
+     ; tycon <- buildSynTyCon tc_name tyvars rhs rhs_kind fam

      ; return $ ATyCon tycon
      }
      ; return $ ATyCon tycon
      }

+   where
+     mk_doc n = ptext (sLit "Type syonym") <+> ppr n
+     tc_syn_rhs kind Nothing   = return (OpenSynTyCon kind Nothing)
+     tc_syn_rhs _    (Just ty) = do { rhs_ty <- tcIfaceType ty
+                                   ; return (SynonymTyCon rhs_ty) }
+     tc_syn_fam Nothing 
+       = return Nothing
+     tc_syn_fam (Just (fam, tys)) 
+       = do { famTyCon <- tcIfaceTyCon fam
+           ; insttys <- mapM tcIfaceType tys
+                   ; return $ Just (famTyCon, insttys) }

 
 tcIfaceDecl ignore_prags
            (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, 
 
 tcIfaceDecl ignore_prags
            (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, 

@@ -434,7 +434,7 @@ tcIfaceDecl ignore_prags
                -- it mentions unless it's necessray to do so
          ; return (op_name, dm, op_ty) }
 
                -- it mentions unless it's necessray to do so
          ; return (op_name, dm, op_ty) }
 

-   mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
+   mk_doc op_name op_ty = ptext (sLit "Class op") <+> sep [ppr op_name, ppr op_ty]

 
    tc_fd (tvs1, tvs2) = do { tvs1' <- mapM tcIfaceTyVar tvs1
                           ; tvs2' <- mapM tcIfaceTyVar tvs2
 
    tc_fd (tvs1, tvs2) = do { tvs1' <- mapM tcIfaceTyVar tvs1
                           ; tvs2' <- mapM tcIfaceTyVar tvs2

@@ -453,12 +453,13 @@ tcIfaceDecl ignore_prags
      ATyCon (setTyConArgPoss tycon poss)
    setTyThingPoss _              _ = panic "TcIface.setTyThingPoss"
 
      ATyCon (setTyConArgPoss tycon poss)
    setTyThingPoss _              _ = panic "TcIface.setTyThingPoss"
 

-tcIfaceDecl ignore_prags (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
+tcIfaceDecl _ (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})

   = do { name <- lookupIfaceTop rdr_name
        ; return (ATyCon (mkForeignTyCon name ext_name 
                                         liftedTypeKind 0)) }
 
   = do { name <- lookupIfaceTop rdr_name
        ; return (ATyCon (mkForeignTyCon name ext_name 
                                         liftedTypeKind 0)) }
 

-tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
+tcIfaceDataCons :: Name -> TyCon -> [TyVar] -> IfaceConDecls -> IfL AlgTyConRhs
+tcIfaceDataCons tycon_name tycon _ if_cons

   = case if_cons of
        IfAbstractTyCon  -> return mkAbstractTyConRhs
        IfOpenDataTyCon  -> return mkOpenDataTyConRhs
   = case if_cons of
        IfAbstractTyCon  -> return mkAbstractTyConRhs
        IfOpenDataTyCon  -> return mkOpenDataTyConRhs

@@ -497,8 +498,9 @@ tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
                        eq_spec theta 
                       arg_tys tycon
        }
                        eq_spec theta 
                       arg_tys tycon
        }

-    mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
+    mk_doc con_name = ptext (sLit "Constructor") <+> ppr con_name

 
 

+tcIfaceEqSpec :: [(OccName, IfaceType)] -> IfL [(TyVar, Type)]

 tcIfaceEqSpec spec
   = mapM do_item spec
   where
 tcIfaceEqSpec spec
   = mapM do_item spec
   where

@@ -507,6 +509,23 @@ tcIfaceEqSpec spec
                               ; return (tv,ty) }
 \end{code}
 
                               ; return (tv,ty) }
 \end{code}
 

+Note [Synonym kind loop]
+~~~~~~~~~~~~~~~~~~~~~~~~
+Notice that we eagerly grab the *kind* from the interface file, but
+build a forkM thunk for the *rhs* (and family stuff).  To see why, 
+consider this (Trac #2412)
+
+M.hs:       module M where { import X; data T = MkT S }
+X.hs:       module X where { import {-# SOURCE #-} M; type S = T }
+M.hs-boot:  module M where { data T }
+
+When kind-checking M.hs we need S's kind.  But we do not want to
+find S's kind from (typeKind S-rhs), because we don't want to look at
+S-rhs yet!  Since S is imported from X.hi, S gets just one chance to
+be defined, and we must not do that until we've finished with M.T.
+
+Solution: record S's kind in the interface file; now we can safely
+look at it.

 
 %************************************************************************
 %*                                                                     *
 
 %************************************************************************
 %*                                                                     *

@@ -517,9 +536,8 @@ tcIfaceEqSpec spec
 \begin{code}
 tcIfaceInst :: IfaceInst -> IfL Instance
 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
 \begin{code}
 tcIfaceInst :: IfaceInst -> IfL Instance
 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,

-                        ifInstCls = cls, ifInstTys = mb_tcs,
-                        ifInstOrph = orph })
-  = do { dfun    <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
+                        ifInstCls = cls, ifInstTys = mb_tcs })
+  = do { dfun    <- forkM (ptext (sLit "Dict fun") <+> ppr dfun_occ) $

                     tcIfaceExtId dfun_occ
         ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
        ; return (mkImportedInstance cls mb_tcs' dfun oflag) }
                     tcIfaceExtId dfun_occ
         ; let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
        ; return (mkImportedInstance cls mb_tcs' dfun oflag) }

@@ -527,8 +545,8 @@ tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
 tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
 tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon, 
                               ifFamInstFam = fam, ifFamInstTys = mb_tcs })
 tcIfaceFamInst :: IfaceFamInst -> IfL FamInst
 tcIfaceFamInst (IfaceFamInst { ifFamInstTyCon = tycon, 
                               ifFamInstFam = fam, ifFamInstTys = mb_tcs })

---     { tycon'  <- forkM (ptext SLIT("Inst tycon") <+> ppr tycon) $
--- ^^^this line doesn't work, but vvv this does => CPP in Haskell = evil!
+--     { tycon'  <- forkM (ptext (sLit "Inst tycon") <+> ppr tycon) $
+-- the above line doesn't work, but this below does => CPP in Haskell = evil!

     = do tycon'  <- forkM (text ("Inst tycon") <+> ppr tycon) $
                     tcIfaceTyCon tycon
          let mb_tcs' = map (fmap ifaceTyConName) mb_tcs
     = do tycon'  <- forkM (text ("Inst tycon") <+> ppr tycon) $
                     tcIfaceTyCon tycon
          let mb_tcs' = map (fmap ifaceTyConName) mb_tcs

@@ -556,11 +574,10 @@ tcIfaceRules ignore_prags if_rules
 
 tcIfaceRule :: IfaceRule -> IfL CoreRule
 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
 
 tcIfaceRule :: IfaceRule -> IfL CoreRule
 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,

-                       ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
-                       ifRuleOrph = orph })
+                       ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs })

   = do { ~(bndrs', args', rhs') <- 
                -- Typecheck the payload lazily, in the hope it'll never be looked at
   = do { ~(bndrs', args', rhs') <- 
                -- Typecheck the payload lazily, in the hope it'll never be looked at

-               forkM (ptext SLIT("Rule") <+> ftext name) $
+               forkM (ptext (sLit "Rule") <+> ftext name) $

                bindIfaceBndrs bndrs                      $ \ bndrs' ->
                do { args' <- mapM tcIfaceExpr args
                   ; rhs'  <- tcIfaceExpr rhs
                bindIfaceBndrs bndrs                      $ \ bndrs' ->
                do { args' <- mapM tcIfaceExpr args
                   ; rhs'  <- tcIfaceExpr rhs

@@ -583,9 +600,9 @@ tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bnd
        -- to write them out in coreRuleToIfaceRule
     ifTopFreeName :: IfaceExpr -> Maybe Name
     ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)
        -- to write them out in coreRuleToIfaceRule
     ifTopFreeName :: IfaceExpr -> Maybe Name
     ifTopFreeName (IfaceType (IfaceTyConApp tc _ )) = Just (ifaceTyConName tc)

-    ifTopFreeName (IfaceApp f a)                    = ifTopFreeName f
+    ifTopFreeName (IfaceApp f _)                    = ifTopFreeName f

     ifTopFreeName (IfaceExt n)                      = Just n
     ifTopFreeName (IfaceExt n)                      = Just n

-    ifTopFreeName other                             = Nothing
+    ifTopFreeName _                                 = Nothing

 \end{code}
 
 
 \end{code}
 
 

@@ -693,6 +710,7 @@ tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceT
 tcIfaceType (IfaceForAllTy tv t)  = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
 tcIfaceType (IfacePredTy st)      = do { st' <- tcIfacePredType st; return (PredTy st') }
 
 tcIfaceType (IfaceForAllTy tv t)  = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
 tcIfaceType (IfacePredTy st)      = do { st' <- tcIfacePredType st; return (PredTy st') }
 

+tcIfaceTypes :: [IfaceType] -> IfL [Type]

 tcIfaceTypes tys = mapM tcIfaceType tys
 
 -----------------------------------------
 tcIfaceTypes tys = mapM tcIfaceType tys
 
 -----------------------------------------

@@ -798,6 +816,9 @@ tcIfaceExpr (IfaceNote note expr) = do
         IfaceCoreNote n   -> return (Note (CoreNote n) expr')
 
 -------------------------
         IfaceCoreNote n   -> return (Note (CoreNote n) expr')
 
 -------------------------

+tcIfaceAlt :: CoreExpr -> (TyCon, [Type])
+           -> (IfaceConAlt, [FastString], IfaceExpr)
+           -> IfL (AltCon, [TyVar], CoreExpr)

 tcIfaceAlt _ _ (IfaceDefault, names, rhs)
   = ASSERT( null names ) do
     rhs' <- tcIfaceExpr rhs
 tcIfaceAlt _ _ (IfaceDefault, names, rhs)
   = ASSERT( null names ) do
     rhs' <- tcIfaceExpr rhs

@@ -813,17 +834,17 @@ tcIfaceAlt _ _ (IfaceLitAlt lit, names, rhs)
 -- work them out.  True enough, but its not that easy!
 tcIfaceAlt scrut (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
   = do { con <- tcIfaceDataCon data_occ
 -- work them out.  True enough, but its not that easy!
 tcIfaceAlt scrut (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
   = do { con <- tcIfaceDataCon data_occ

-#ifdef DEBUG
-       ; when (not (con `elem` tyConDataCons tycon))
+       ; when (debugIsOn && not (con `elem` tyConDataCons tycon))

               (failIfM (ppr scrut $$ ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon)))
               (failIfM (ppr scrut $$ ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon)))

-#endif

        ; tcIfaceDataAlt con inst_tys arg_strs rhs }
                  
        ; tcIfaceDataAlt con inst_tys arg_strs rhs }
                  

-tcIfaceAlt _ (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
+tcIfaceAlt _ (tycon, inst_tys) (IfaceTupleAlt _boxity, arg_occs, rhs)

   = ASSERT( isTupleTyCon tycon )
     do { let [data_con] = tyConDataCons tycon
        ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
 
   = ASSERT( isTupleTyCon tycon )
     do { let [data_con] = tyConDataCons tycon
        ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
 

+tcIfaceDataAlt :: DataCon -> [Type] -> [FastString] -> IfaceExpr
+               -> IfL (AltCon, [TyVar], CoreExpr)

 tcIfaceDataAlt con inst_tys arg_strs rhs
   = do { us <- newUniqueSupply
        ; let uniqs = uniqsFromSupply us
 tcIfaceDataAlt con inst_tys arg_strs rhs
   = do { us <- newUniqueSupply
        ; let uniqs = uniqsFromSupply us

@@ -880,6 +901,7 @@ tcIdInfo ignore_prags name ty info
     -- we start; default assumption is that it has CAFs
     init_info = vanillaIdInfo
 
     -- we start; default assumption is that it has CAFs
     init_info = vanillaIdInfo
 

+    tcPrag :: IdInfo -> IfaceInfoItem -> IfL IdInfo

     tcPrag info HsNoCafRefs         = return (info `setCafInfo`   NoCafRefs)
     tcPrag info (HsArity arity)     = return (info `setArityInfo` arity)
     tcPrag info (HsStrictness str)  = return (info `setAllStrictnessInfo` Just str)
     tcPrag info HsNoCafRefs         = return (info `setCafInfo`   NoCafRefs)
     tcPrag info (HsArity arity)     = return (info `setArityInfo` arity)
     tcPrag info (HsStrictness str)  = return (info `setAllStrictnessInfo` Just str)

@@ -899,6 +921,7 @@ tcIdInfo ignore_prags name ty info
 \end{code}
 
 \begin{code}
 \end{code}
 
 \begin{code}

+tcWorkerInfo :: Type -> IdInfo -> Name -> Arity -> IfL IdInfo

 tcWorkerInfo ty info wkr arity
   = do         { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
 
 tcWorkerInfo ty info wkr arity
   = do         { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
 

@@ -979,14 +1002,14 @@ tcIfaceGlobal name
                { type_env <- setLclEnv () get_type_env         -- yuk
                ; case lookupNameEnv type_env name of
                        Just thing -> return thing
                { type_env <- setLclEnv () get_type_env         -- yuk
                ; case lookupNameEnv type_env name of
                        Just thing -> return thing

-                       Nothing    -> pprPanic "tcIfaceGlobal (local): not found:"  
+                       Nothing   -> pprPanic "tcIfaceGlobal (local): not found:"  

                                                (ppr name $$ ppr type_env) }
 
                                                (ppr name $$ ppr type_env) }
 

-         ; other -> do
+         ; _ -> do

 
 

-       { (eps,hpt) <- getEpsAndHpt
-       ; dflags <- getDOpts
-       ; case lookupType dflags hpt (eps_PTE eps) name of {
+       { hsc_env <- getTopEnv
+        ; mb_thing <- liftIO (lookupTypeHscEnv hsc_env name)
+       ; case mb_thing of {

            Just thing -> return thing ;
            Nothing    -> do
 
            Just thing -> return thing ;
            Nothing    -> do
 

@@ -1037,13 +1060,11 @@ tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
 tcIfaceTyCon (IfaceTc name)     = do { thing <- tcIfaceGlobal name 
                                     ; return (check_tc (tyThingTyCon thing)) }
   where
 tcIfaceTyCon (IfaceTc name)     = do { thing <- tcIfaceGlobal name 
                                     ; return (check_tc (tyThingTyCon thing)) }
   where

-#ifdef DEBUG
-    check_tc tc = case toIfaceTyCon tc of
-                  IfaceTc _ -> tc
-                  other     -> pprTrace "check_tc" (ppr tc) tc
-#else
-    check_tc tc = tc
-#endif
+    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
 -- we should be okay just returning Kind constructors without extra loading
 tcIfaceTyCon IfaceLiftedTypeKindTc   = return liftedTypeKindTyCon
 tcIfaceTyCon IfaceOpenTypeKindTc     = return openTypeKindTyCon

@@ -1066,13 +1087,13 @@ tcIfaceDataCon :: Name -> IfL DataCon
 tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
                         ; case thing of
                                ADataCon dc -> return dc
 tcIfaceDataCon name = do { thing <- tcIfaceGlobal name
                         ; case thing of
                                ADataCon dc -> return dc

-                               other   -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }
+                               _       -> pprPanic "tcIfaceExtDC" (ppr name$$ ppr thing) }

 
 tcIfaceExtId :: Name -> IfL Id
 tcIfaceExtId name = do { thing <- tcIfaceGlobal name
                       ; case thing of
                          AnId id -> return id
 
 tcIfaceExtId :: Name -> IfL Id
 tcIfaceExtId name = do { thing <- tcIfaceGlobal name
                       ; case thing of
                          AnId id -> return id

-                         other   -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }
+                         _       -> pprPanic "tcIfaceExtId" (ppr name$$ ppr thing) }

 \end{code}
 
 %************************************************************************
 \end{code}
 
 %************************************************************************

@@ -1099,6 +1120,7 @@ bindIfaceBndrs (b:bs) thing_inside
     thing_inside (b':bs')
 
 -----------------------
     thing_inside (b':bs')
 
 -----------------------

+tcIfaceLetBndr :: IfaceLetBndr -> IfL Id

 tcIfaceLetBndr (IfLetBndr fs ty info)
   = do { name <- newIfaceName (mkVarOccFS fs)
        ; ty' <- tcIfaceType ty
 tcIfaceLetBndr (IfLetBndr fs ty info)
   = do { name <- newIfaceName (mkVarOccFS fs)
        ; ty' <- tcIfaceType ty

@@ -1125,13 +1147,13 @@ newExtCoreBndr (IfLetBndr var ty _)    -- Ignoring IdInfo for now
 -----------------------
 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
 bindIfaceTyVar (occ,kind) thing_inside
 -----------------------
 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
 bindIfaceTyVar (occ,kind) thing_inside

-  = do { name <- newIfaceName (mkTyVarOcc occ)
+  = do { name <- newIfaceName (mkTyVarOccFS occ)

        ; tyvar <- mk_iface_tyvar name kind
        ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
 
 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
 bindIfaceTyVars bndrs thing_inside
        ; tyvar <- mk_iface_tyvar name kind
        ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
 
 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
 bindIfaceTyVars bndrs thing_inside

-  = do { names <- newIfaceNames (map mkTyVarOcc occs)
+  = do { names <- newIfaceNames (map mkTyVarOccFS occs)

        ; tyvars <- zipWithM mk_iface_tyvar names kinds
        ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
   where
        ; tyvars <- zipWithM mk_iface_tyvar names kinds
        ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
   where