Fix scoped type variables for expression type signatures

[ghc-hetmet.git] / compiler / simplCore / Simplify.lhs

diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index 43edcf5..dffdd75 100644 (file)
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -13,7 +13,7 @@ import DynFlags       ( dopt, DynFlag(Opt_D_dump_inlinings),
                        )
 import SimplMonad
 import SimplEnv        
-import SimplUtils      ( mkCase, mkLam, mkDataConAlt,
+import SimplUtils      ( mkCase, mkLam, 
                          SimplCont(..), DupFlag(..), LetRhsFlag(..), 
                          mkRhsStop, mkBoringStop,  mkLazyArgStop, pushContArgs,
                          contResultType, countArgs, contIsDupable, contIsRhsOrArg,
@@ -26,8 +26,6 @@ import Id             ( Id, idType, idInfo, idArity, isDataConWorkId,
                          idNewDemandInfo, setIdInfo, 
                          setIdOccInfo, zapLamIdInfo, setOneShotLambda
                        )
-import MkId            ( eRROR_ID )
-import Literal         ( mkStringLit )
 import IdInfo          ( OccInfo(..), isLoopBreaker,
                          setArityInfo, zapDemandInfo,
                          setUnfoldingInfo, 
@@ -35,7 +33,7 @@ import IdInfo         ( OccInfo(..), isLoopBreaker,
                        )
 import NewDemand       ( isStrictDmd )
 import TcGadt          ( dataConCanMatch )
-import DataCon         ( DataCon, dataConTyCon, dataConRepStrictness )
+import DataCon         ( dataConTyCon, dataConRepStrictness )
 import TyCon           ( tyConArity, isAlgTyCon, isNewTyCon, tyConDataCons_maybe )
 import CoreSyn
 import PprCore         ( pprParendExpr, pprCoreExpr )
@@ -44,19 +42,18 @@ import CoreUtils    ( exprIsDupable, exprIsTrivial, needsCaseBinding,
                          exprIsConApp_maybe, mkPiTypes, findAlt, 
                          exprType, exprIsHNF, findDefault, mergeAlts,
                          exprOkForSpeculation, exprArity, 
-                         mkCoerce, mkSCC, mkInlineMe, applyTypeToArg
+                         mkCoerce, mkSCC, mkInlineMe, applyTypeToArg,
+                          dataConRepInstPat
                        )
 import Rules           ( lookupRule )
 import BasicTypes      ( isMarkedStrict )
 import CostCentre      ( currentCCS )
 import Type            ( TvSubstEnv, isUnLiftedType, seqType, tyConAppArgs, funArgTy,
-                         splitFunTy_maybe, splitFunTy, coreEqType, splitTyConApp_maybe,
-                         isTyVarTy, mkTyVarTys, isFunTy, tcEqType
+                         coreEqType, splitTyConApp_maybe,
+                         isTyVarTy, isFunTy, tcEqType
                        )
 import Coercion         ( Coercion, coercionKind,
-                          mkTransCoercion, mkLeftCoercion, mkRightCoercion, 
-                          mkSymCoercion, splitCoercionKind_maybe, decomposeCo  )
-import Var             ( tyVarKind, mkTyVar )
+                          mkTransCoercion, mkSymCoercion, splitCoercionKind_maybe, decomposeCo  )
 import VarEnv          ( elemVarEnv, emptyVarEnv )
 import TysPrim         ( realWorldStatePrimTy )
 import PrelInfo                ( realWorldPrimId )
@@ -611,7 +608,6 @@ completeLazyBind env top_lvl old_bndr new_bndr new_rhs
        -- means that we can avoid tests in exprIsConApp, for example.
        -- This is important: if exprIsConApp says 'yes' for a recursive
        -- thing, then we can get into an infinite loop
-
        -- If the unfolding is a value, the demand info may
        -- go pear-shaped, so we nuke it.  Example:
        --      let x = (a,b) in
@@ -814,9 +810,12 @@ simplCast env body co cont
            -- t2 :=: s2 with left and right on the curried form: 
            --    (->) t1 t2 :=: (->) s1 s2
            [co1, co2] = decomposeCo 2 co
-           new_arg    = mkCoerce (mkSymCoercion co1) (substExpr arg_env arg)
-           arg_env    = setInScope arg_se env
-           result     = ApplyTo dup new_arg (zapSubstEnv env) (addCoerce co2 cont)
+           new_arg    = mkCoerce (mkSymCoercion co1) arg'
+          arg'       = case arg_se of
+                         Nothing     -> arg
+                         Just arg_se -> substExpr (setInScope arg_se env) arg
+           result     = ApplyTo dup new_arg (Just $ zapSubstEnv env) 
+                               (addCoerce co2 cont)
        addCoerce co cont = CoerceIt co cont
     in
     simplType env co           `thenSmpl` \ co' ->
@@ -1517,6 +1516,7 @@ simplDefault :: SimplEnv
 
 simplDefault env case_bndr' imposs_cons cont Nothing
   = return []  -- No default branch
+
 simplDefault env case_bndr' imposs_cons cont (Just rhs)
   |    -- This branch handles the case where we are 
        -- scrutinisng an algebraic data type
@@ -1549,7 +1549,10 @@ simplDefault env case_bndr' imposs_cons cont (Just rhs)
 
        [con] ->        -- It matches exactly one constructor, so fill it in
                 do { tick (FillInCaseDefault case_bndr')
-                   ; con_alt <- mkDataConAlt con inst_tys rhs
+                    ; us <- getUniquesSmpl
+                    ; let (ex_tvs, co_tvs, arg_ids) =
+                              dataConRepInstPat us con inst_tys
+                    ; let con_alt = (DataAlt con, ex_tvs ++ co_tvs ++ arg_ids, rhs)
                    ; Just (_, alt') <- simplAlt env [] case_bndr' cont con_alt
                        -- The simplAlt must succeed with Just because we have
                        -- already filtered out construtors that can't match
@@ -1557,7 +1560,7 @@ simplDefault env case_bndr' imposs_cons cont (Just rhs)
 
        two_or_more -> simplify_default (map DataAlt gadt_imposs ++ imposs_cons)
 
-  | otherwise
+  | otherwise 
   = simplify_default imposs_cons
   where
     cant_match tys data_con = not (dataConCanMatch data_con tys)
@@ -1693,7 +1696,7 @@ knownCon env scrut con args bndr alts cont
                                  simplExprF env rhs cont
 
        (DataAlt dc, bs, rhs)  
-               -> ASSERT( n_drop_tys + length bs == length args )
+               -> -- ASSERT( n_drop_tys + length bs == length args )
                   bind_args env dead_bndr bs (drop n_drop_tys args)    $ \ env ->
                   let
                        -- It's useful to bind bndr to scrut, rather than to a fresh
@@ -1713,6 +1716,7 @@ knownCon env scrut con args bndr alts cont
                   simplNonRecX env bndr bndr_rhs               $ \ env ->
                   simplExprF env rhs cont
                where
+                  dead_bndr  = isDeadBinder bndr
                   n_drop_tys = tyConArity (dataConTyCon dc)
 
 -- Ugh!