From 2d367f855c3556166d24cf538d5c34d0ff596a2f Mon Sep 17 00:00:00 2001
From: "simonpj@microsoft.com" <unknown>
Date: Mon, 15 Nov 2010 23:21:42 +0000
Subject: [PATCH] Fix -fwarn-missing-import-lists (fix Trac #4489)

---
 compiler/rename/RnNames.lhs |   23 ++++++++++++++---------
 docs/users_guide/flags.xml  |    3 ++-
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/compiler/rename/RnNames.lhs b/compiler/rename/RnNames.lhs
index a9a9c46..a1cadb3 100644
--- 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 ()
 
@@ -1552,6 +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 ":"), 
diff --git a/docs/users_guide/flags.xml b/docs/users_guide/flags.xml
index b80ada7..8482a7c 100644
--- a/docs/users_guide/flags.xml
+++ b/docs/users_guide/flags.xml
@@ -1143,7 +1143,8 @@
 
 	  <row>
 	    <entry><option>-fwarn-missing-import-lists</option></entry>
-	    <entry>warn when explicit imports lack an import list</entry>
+	    <entry>warn when an import declaration does not explicitly 
+                   list all the names brought into scope</entry>
 	    <entry>dynamic</entry>
 	    <entry><option>-fnowarn-missing-import-lists</option></entry>
 	  </row>
-- 
1.7.10.4