From: simonpj <unknown>
Date: Wed, 9 Oct 2002 16:28:57 +0000 (+0000)
Subject: [project @ 2002-10-09 16:28:56 by simonpj]
X-Git-Tag: Approx_11550_changesets_converted~1579
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=e2bcc01c862ab0c4a12040172429075aa5921b49;p=ghc-hetmet.git

[project @ 2002-10-09 16:28:56 by simonpj]
Fix and simplify renamer warnings about export lists
---

diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs
index f1c7992..5877872 100644
--- a/ghc/compiler/rename/RnNames.lhs
+++ b/ghc/compiler/rename/RnNames.lhs
@@ -180,7 +180,7 @@ importsFromImportDecl this_mod_name
 
 	mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) 
 	gbl_env      = mkGlobalRdrEnv qual_mod unqual_imp mk_prov filtered_avails deprecs
-	imports      = mkImportAvails qual_mod unqual_imp gbl_env filtered_avails
+	imports      = mkImportAvails qual_mod unqual_imp filtered_avails
     in
     returnM (gbl_env, imports { imp_mods = dir_imp})
     }
@@ -241,9 +241,9 @@ importsFromLocalDecls group
 	    -- Optimisation: filter out names for built-in syntax
 	    -- They just clutter up the environment (esp tuples), and the parser
 	    -- will generate Exact RdrNames for them, so the cluttered
-	    -- envt is no use.  To avoid doing this filter all the type,
+	    -- envt is no use.  To avoid doing this filter all the time,
 	    -- we use -fno-implicit-prelude as a clue that the filter is
-	    -- worth while.  Really, it's only useful for Base and Tuple.
+	    -- worth while.  Really, it's only useful for GHC.Base and GHC.Tuple.
 	    --
 	    -- It's worth doing because it makes the environment smaller for
 	    -- every module that imports the Prelude
@@ -255,7 +255,7 @@ importsFromLocalDecls group
 	    -- but that stops them being Exact, so they get looked up.  Sigh.
 	    -- It doesn't matter because it only affects the Data.Tuple really.
 	    -- The important thing is to trim down the exports.
-	imports = mkImportAvails mod_name unqual_imp gbl_env avails'
+	imports = mkImportAvails mod_name unqual_imp avails'
  	avails' | implicit_prelude = filter not_built_in_syntax avails
 		| otherwise	   = avails
 	not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a))
@@ -513,12 +513,14 @@ exports_from_avail export_items warn_dup_exports
 	= case lookupModuleEnvByName mod_avail_env mod of
 	    Nothing	        -> addErr (modExportErr mod)	`thenM_`
 				   returnM acc
-	    Just mod_avails 
-		-> foldlM (check_occs warn_dup_exports ie) 
-			  occs mod_avails	 	   `thenM` \ occs' ->
-		   let
+	    Just avail_env
+		-> let
+			mod_avails = availEnvElts avail_env
 			avails' = foldl addAvail avails mod_avails
 		   in
+		   foldlM (check_occs warn_dup_exports ie) 
+			  occs mod_avails	`thenM` \ occs' ->
+
 		   returnM (mod:mods, occs', avails')
 
     exports_from_item acc@(mods, occs, avails) ie
diff --git a/ghc/compiler/typecheck/TcRnTypes.lhs b/ghc/compiler/typecheck/TcRnTypes.lhs
index 81909bf..2a3ca22 100644
--- a/ghc/compiler/typecheck/TcRnTypes.lhs
+++ b/ghc/compiler/typecheck/TcRnTypes.lhs
@@ -48,7 +48,7 @@ import RnHsSyn		( RenamedHsExpr, RenamedPat, RenamedArithSeqInfo )
 import HscTypes		( GhciMode, ExternalPackageState, HomePackageTable, NameCache,
 			  GlobalRdrEnv, LocalRdrEnv, FixityEnv, TypeEnv, TyThing, 
 			  Avails, GenAvailInfo(..), AvailInfo, availName,
-			  IsBootInterface, Deprecations, unQualInScope )
+			  IsBootInterface, Deprecations )
 import TcType		( TcTyVarSet, TcType, TcTauType, TcThetaType, TcPredType, TcKind,
 			  tcCmpPred, tcCmpType, tcCmpTypes )
 import InstEnv		( DFunId, InstEnv )
@@ -468,13 +468,13 @@ data ImportAvails
 		-- i.e. *excluding* class ops and constructors
 		--	(which appear inside their parent AvailTC)
 
-	imp_unqual :: ModuleEnv Avails,
+	imp_unqual :: ModuleEnv AvailEnv,
 		-- Used to figure out "module M" export specifiers
 		-- Domain is only modules with *unqualified* imports
 		-- (see 1.4 Report Section 5.1.1)
-		-- The list of Avails is cumulative, not necessarily
-		-- nicely uniquified. For example, we might have Maybe(Nothing)
-		-- and Maybe(Just) in the list, separately.
+		-- We keep the stuff as an AvailEnv so that it's easy to 
+		-- combine stuff coming from different (unqualified) 
+		-- imports of the same module
 
 	imp_mods :: ModuleEnv (Module, Bool)
 		-- Domain is all directly-imported modules
@@ -499,12 +499,12 @@ plusImportAvails
   (ImportAvails { imp_env = env1, imp_unqual = unqual1, imp_mods = mods1 })
   (ImportAvails { imp_env = env2, imp_unqual = unqual2, imp_mods = mods2 })
   = ImportAvails { imp_env    = env1 `plusAvailEnv` env2, 
-		   imp_unqual = plusModuleEnv_C (++) unqual1 unqual2, 
+		   imp_unqual = plusModuleEnv_C plusAvailEnv unqual1 unqual2, 
 		   imp_mods   = mods1 `plusModuleEnv` mods2 }
 
 mkImportAvails :: ModuleName -> Bool
-	       -> GlobalRdrEnv -> [AvailInfo] -> ImportAvails
-mkImportAvails mod_name unqual_imp gbl_env avails 
+	       -> [AvailInfo] -> ImportAvails
+mkImportAvails mod_name unqual_imp avails 
   = ImportAvails { imp_unqual = mod_avail_env, 
 		   imp_env    = entity_avail_env,
 		   imp_mods   = emptyModuleEnv }-- Stays empty for module being compiled;
@@ -517,8 +517,8 @@ mkImportAvails mod_name unqual_imp gbl_env avails
 	--	module M ( module P ) where ...
 	-- Then we must export whatever came from P unqualified.
 
-    unqual_avails | not unqual_imp = []	-- Short cut when no unqualified imports
-		  | otherwise      = pruneAvails (unQualInScope gbl_env) avails
+    unqual_avails | not unqual_imp = emptyAvailEnv	-- Qualified import
+		  | otherwise      = entity_avail_env	-- Unqualified import
 
     entity_avail_env = foldl insert emptyAvailEnv avails
     insert env avail = extendNameEnv_C plusAvail env (availName avail) avail