[project @ 2004-12-02 17:18:15 by simonpj]

[ghc-hetmet.git] / ghc / compiler / rename / RnNames.lhs

diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs
index e043ab0..5b426fe 100644 (file)
--- a/ghc/compiler/rename/RnNames.lhs
+++ b/ghc/compiler/rename/RnNames.lhs
@@ -75,9 +75,9 @@ rnImports imports
                -- Do the non {- SOURCE -} ones first, so that we get a helpful
                -- warning for {- SOURCE -} ones that are unnecessary
          this_mod <- getModule
-       ; opt_no_prelude <- doptM Opt_NoImplicitPrelude
+       ; implicit_prelude <- doptM Opt_ImplicitPrelude
        ; let
-           all_imports      = mk_prel_imports this_mod opt_no_prelude ++ imports
+           all_imports        = mk_prel_imports this_mod implicit_prelude ++ imports
            (source, ordinary) = partition is_source_import all_imports
            is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot
 
@@ -101,10 +101,10 @@ rnImports imports
        -- NB: opt_NoImplicitPrelude is slightly different to import Prelude ();
        -- because the former doesn't even look at Prelude.hi for instance 
        -- declarations, whereas the latter does.
-    mk_prel_imports this_mod no_prelude
+    mk_prel_imports this_mod implicit_prelude
        |  this_mod == pRELUDE
        || explicit_prelude_import
-       || no_prelude
+       || not implicit_prelude
        = []
 
        | otherwise = [preludeImportDecl]
@@ -251,18 +251,29 @@ exportsToAvails :: [IfaceExport] -> TcRnIf gbl lcl NameSet
 exportsToAvails exports 
   = foldlM do_one emptyNameSet exports
   where
-    do_one acc (mod, exports)       = foldlM (do_avail mod) acc exports
-    do_avail mod acc (Avail n)      = do { n' <- lookupOrig mod n; 
-                                        ; return (addOneToNameSet acc n') }
-    do_avail mod acc (AvailTC n ns) = do { n' <- lookupOrig mod n
-                                        ; ns' <- mappM (lookup_sub n') ns
-                                        ; return (addListToNameSet acc (n':ns')) }
+    do_one acc (mod, exports)  = foldlM (do_avail mod) acc exports
+    do_avail mod acc (Avail n) = do { n' <- lookupOrig mod n; 
+                                   ; return (addOneToNameSet acc n') }
+    do_avail mod acc (AvailTC p_occ occs) 
+       = do { p_name <- lookupOrig mod p_occ
+            ; ns <- mappM (lookup_sub p_name) occs
+            ; return (addListToNameSet acc ns) }
+       -- Remember that 'occs' is all the exported things, including
+       -- the parent.  It's possible to export just class ops without
+       -- the class, via C( op ). If the class was exported too we'd
+       -- have C( C, op )
        where
-         lookup_sub parent occ = newGlobalBinder mod occ (Just parent) noSrcLoc
-               -- Hack alert! Notice the newGlobalBinder.  It ensures that the subordinate 
-               -- names record their parent; and that in turn ensures that the GlobalRdrEnv
-               -- has the correct parent for all the names in its range.
-               -- For imported things, we only suck in the binding site later, if ever.
+          lookup_sub parent occ 
+               = newGlobalBinder mod occ mb_parent noSrcLoc
+               where
+                 mb_parent | occ == p_occ = Nothing
+                           | otherwise    = Just parent
+
+       -- The use of newGlobalBinder here (rather than lookupOrig) 
+       -- ensures that the subordinate names record their parent; 
+       -- and that in turn ensures that the GlobalRdrEnv
+       -- has the correct parent for all the names in its range.
+       -- For imported things, we only suck in the binding site later, if ever.
        -- Reason for all this:
        --   Suppose module M exports type A.T, and constructor A.MkT
        --   Then, we know that A.MkT is a subordinate name of A.T,
@@ -309,7 +320,7 @@ importsFromLocalDecls group
        -- printer returns False.  It seems awkward to fix, unfortunately.
     mappM_ addDupDeclErr dups                  `thenM_` 
 
-    doptM Opt_NoImplicitPrelude                `thenM` \ implicit_prelude ->
+    doptM Opt_ImplicitPrelude          `thenM` \ implicit_prelude ->
     let
        prov     = LocalDef this_mod
        gbl_env  = mkGlobalRdrEnv gres
@@ -335,8 +346,8 @@ importsFromLocalDecls group
            -- Sigh. It doesn't matter because it only affects the Data.Tuple really.
            -- The important thing is to trim down the exports.
        filtered_names 
-         | implicit_prelude = filter (not . isBuiltInSyntax) all_names
-         | otherwise        = all_names
+         | implicit_prelude = all_names
+         | otherwise        = filter (not . isBuiltInSyntax) all_names
 
        imports = emptyImportAvails {
                        imp_env = unitModuleEnv this_mod $