[project @ 2004-01-12 14:36:28 by simonpj]

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

diff --git a/ghc/compiler/iface/TcIface.lhs b/ghc/compiler/iface/TcIface.lhs
index 51bf028..57c40de 100644 (file)
--- a/ghc/compiler/iface/TcIface.lhs
+++ b/ghc/compiler/iface/TcIface.lhs
@@ -6,7 +6,7 @@
 \begin{code}
 module TcIface ( 
        tcImportDecl, typecheckIface,
-       tcIfaceKind, loadImportedInsts, loadImportedRules,
+       loadImportedInsts, loadImportedRules,
        tcExtCoreBindings
  ) where
 #include "HsVersions.h"
@@ -20,8 +20,7 @@ import IfaceEnv               ( lookupIfaceTop, newGlobalBinder, lookupOrig,
                          newIfaceName, newIfaceNames )
 import BuildTyCl       ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass )
 import TcRnMonad
-import Type            ( Kind, openTypeKind, liftedTypeKind, 
-                         unliftedTypeKind, mkArrowKind, splitTyConApp, 
+import Type            ( liftedTypeKind, splitTyConApp, 
                          mkTyVarTys, mkGenTyConApp, mkTyVarTys, ThetaType, pprClassPred )
 import TypeRep         ( Type(..), PredType(..) )
 import TyCon           ( TyCon, tyConName )
@@ -51,7 +50,7 @@ import DataCon                ( dataConWorkId, dataConExistentialTyVars, dataConArgTys )
 import TysWiredIn      ( tupleCon )
 import Var             ( TyVar, mkTyVar, tyVarKind )
 import Name            ( Name, NamedThing(..), nameModuleName, nameModule, nameOccName, 
-                         isWiredInName, wiredInNameTyThing_maybe, nameParent )
+                         isWiredInName, wiredInNameTyThing_maybe, nameParent, nameParent_maybe )
 import NameEnv
 import OccName         ( OccName )
 import Module          ( Module, ModuleName, moduleName )
@@ -204,12 +203,28 @@ getThing name
 selectDecl :: ExternalPackageState -> Name -> (ExternalPackageState, Maybe IfaceDecl)
 -- Use nameParent to get the parent name of the thing
 selectDecl eps@(EPS { eps_decls = Pool decls_map n_in n_out}) name
-   = case lookupNameEnv decls_map main_name of
+   = case lookupNameEnv decls_map name of {
+               -- This first lookup will usually fail for subordinate names, because
+               -- the relevant decl is the parent decl.
+               -- But, if we export a data type decl abstractly, its selectors
+               -- get separate type signatures in the interface file
+       Just decl -> let 
+                       decls' = delFromNameEnv decls_map name
+                    in
+                    (eps {eps_decls = Pool decls' n_in (n_out+1)}, Just decl) ;
+
+       Nothing -> 
+    case nameParent_maybe name of {
+       Nothing        -> (eps, Nothing ) ;     -- No "parent" 
+       Just main_name ->                       -- Has a parent; try that
+
+    case lookupNameEnv decls_map main_name of {
+       Just decl -> let 
+                       decls' = delFromNameEnv decls_map main_name
+                    in
+                    (eps {eps_decls = Pool decls' n_in (n_out+1)}, Just decl) ;
        Nothing   -> (eps, Nothing)
-       Just decl -> (eps {eps_decls = Pool decls' n_in (n_out+1)}, Just decl)
-   where
-     main_name = nameParent name
-     decls'    = delFromNameEnv decls_map main_name
+    }}}
 \end{code}
 
 %************************************************************************
@@ -529,8 +544,9 @@ selectInsts pool@(Pool insts n_in n_out) cls tycons
 
        -- Reverses the gated decls, but that doesn't matter
     choose2 (gis, decls) (gates, decl)
-       | any (`elem` tycons) gates = (gis,                decl:decls)
-       | otherwise                 = ((gates,decl) : gis, decls)
+       |  null gates   -- Happens when we have 'instance T a where ...'
+        || any (`elem` tycons) gates = (gis,              decl:decls)
+       | otherwise                  = ((gates,decl) : gis, decls)
 \end{code}
 
 %************************************************************************
@@ -611,13 +627,6 @@ tcIfaceRule (IfaceBuiltinRule fn_rdr core_rule)
 %************************************************************************
 
 \begin{code}
-tcIfaceKind :: IfaceKind -> Kind
-tcIfaceKind IfaceOpenTypeKind     = openTypeKind
-tcIfaceKind IfaceLiftedTypeKind   = liftedTypeKind
-tcIfaceKind IfaceUnliftedTypeKind = unliftedTypeKind
-tcIfaceKind (IfaceFunKind k1 k2)  = mkArrowKind (tcIfaceKind k1) (tcIfaceKind k2)
-
------------------------------------------
 tcIfaceType :: IfaceType -> IfL Type
 tcIfaceType (IfaceTyVar n)        = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
 tcIfaceType (IfaceAppTy t1 t2)    = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
@@ -968,5 +977,5 @@ bindIfaceTyVars bndrs thing_inside
   where
     (occs,kinds) = unzip bndrs
 
-mk_iface_tyvar name kind = mkTyVar name (tcIfaceKind kind)
+mk_iface_tyvar name kind = mkTyVar name kind
 \end{code}