Fix -fwarn-missing-import-lists (fix Trac #4489)

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

diff --git a/compiler/rename/RnNames.lhs b/compiler/rename/RnNames.lhs
index bc01bf6..a1cadb3 100644 (file)
--- a/compiler/rename/RnNames.lhs
+++ b/compiler/rename/RnNames.lhs
@@ -108,16 +108,14 @@ rnImportDecl this_mod implicit_prelude
        imp_mod_name = unLoc loc_imp_mod_name
        doc = ppr imp_mod_name <+> ptext (sLit "is directly imported")
 
-    let isExplicit lie = case unLoc lie of
-                         IEThingAll _ -> False
-                         _ -> True
+       -- Check for a missing import list
+       -- (Opt_WarnMissingImportList also checks for T(..) items
+       --  but that is done in checkDodgyImport below)
     case imp_details of
-        Just (False, lies)
-         | all isExplicit lies ->
-            return ()
-        _ ->
-            unless implicit_prelude $
-            ifDOptM Opt_WarnMissingImportList (addWarn (missingImportListWarn imp_mod_name))
+        Just (False, _)       -> return ()
+        _  | implicit_prelude -> return ()
+           | otherwise        -> ifDOptM Opt_WarnMissingImportList $
+                                 addWarn (missingImportListWarn imp_mod_name)
 
     iface <- loadSrcInterface doc imp_mod_name want_boot mb_pkg
 
@@ -588,6 +586,9 @@ filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails
                 | IEThingAll n <- ieRdr, (_, AvailTC _ [_]):_ <- stuff
                 = ifDOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn n))
                 -- NB. use the RdrName for reporting the warning
+               | IEThingAll {} <- ieRdr
+                = ifDOptM Opt_WarnMissingImportList $
+                  addWarn (missingImportListItem ieRdr)
             checkDodgyImport _
                 = return ()
 
@@ -1499,11 +1500,23 @@ exportClashErr global_env name1 name2 ie1 ie2
        = case lookupGRE_Name global_env name of
             (gre:_) -> gre
             []      -> pprPanic "exportClashErr" (ppr name)
-    get_loc name = nameSrcLoc $ gre_name $ get_gre name
+    get_loc name = greSrcSpan (get_gre name)
     (name1', ie1', name2', ie2') = if get_loc name1 < get_loc name2
                                    then (name1, ie1, name2, ie2)
                                    else (name2, ie2, name1, ie1)
 
+-- the SrcSpan that pprNameProvenance prints out depends on whether
+-- the Name is defined locally or not: for a local definition the
+-- definition site is used, otherwise the location of the import
+-- declaration.  We want to sort the export locations in
+-- exportClashErr by this SrcSpan, we need to extract it:
+greSrcSpan :: GlobalRdrElt -> SrcSpan
+greSrcSpan gre
+  | Imported (is:_) <- gre_prov gre = is_dloc (is_decl is)
+  | otherwise                       = name_span
+  where
+    name_span = nameSrcSpan (gre_name gre)
+
 addDupDeclErr :: [Name] -> TcRn ()
 addDupDeclErr []
   = panic "addDupDeclErr: empty list"
@@ -1540,6 +1553,10 @@ missingImportListWarn :: ModuleName -> SDoc
 missingImportListWarn mod
   = ptext (sLit "The module") <+> quotes (ppr mod) <+> ptext (sLit "does not have an explicit import list")
 
+missingImportListItem :: IE RdrName -> SDoc
+missingImportListItem ie
+  = ptext (sLit "The import item") <+> quotes (ppr ie) <+> ptext (sLit "does not have an explicit import list")
+
 moduleWarn :: ModuleName -> WarningTxt -> SDoc
 moduleWarn mod (WarningTxt txt)
   = sep [ ptext (sLit "Module") <+> quotes (ppr mod) <> ptext (sLit ":"),