SafeHaskell: Add safe import flag (not functional)

3 files changed, 33 insertions, 17 deletions

diff --git a/compiler/iface/BinIface.hs b/compiler/iface/BinIface.hs
index 211417debb..904d5a6877 100644
--- a/compiler/iface/BinIface.hs
+++ b/compiler/iface/BinIface.hs
@@ -511,12 +511,14 @@ instance Binary Usage where
         putByte bh 0
 	put_ bh (usg_mod usg)
 	put_ bh (usg_mod_hash usg)
+	put_ bh (usg_safe     usg)
     put_ bh usg@UsageHomeModule{} = do 
         putByte bh 1
 	put_ bh (usg_mod_name usg)
 	put_ bh (usg_mod_hash usg)
 	put_ bh (usg_exports  usg)
 	put_ bh (usg_entities usg)
+	put_ bh (usg_safe     usg)
 
     get bh = do
         h <- getByte bh
@@ -524,14 +526,16 @@ instance Binary Usage where
           0 -> do
             nm    <- get bh
             mod   <- get bh
-            return UsagePackageModule { usg_mod = nm, usg_mod_hash = mod }
+            safe  <- get bh
+            return UsagePackageModule { usg_mod = nm, usg_mod_hash = mod, usg_safe = safe }
           _ -> do
             nm    <- get bh
             mod   <- get bh
             exps  <- get bh
             ents  <- get bh
+            safe  <- get bh
             return UsageHomeModule { usg_mod_name = nm, usg_mod_hash = mod,
-                            usg_exports = exps, usg_entities = ents }
+                     usg_exports = exps, usg_entities = ents, usg_safe = safe }
 
 instance Binary Warnings where
     put_ bh NoWarnings     = putByte bh 0
diff --git a/compiler/iface/LoadIface.lhs b/compiler/iface/LoadIface.lhs
index ccaaf6928a..219ab6a917 100644
--- a/compiler/iface/LoadIface.lhs
+++ b/compiler/iface/LoadIface.lhs
@@ -697,16 +697,22 @@ pprExport (mod, items)
 
 pprUsage :: Usage -> SDoc
 pprUsage usage@UsagePackageModule{}
-  = hsep [ptext (sLit "import"), ppr (usg_mod usage), 
-	  ppr (usg_mod_hash usage)]
+  = pprUsageImport usage usg_mod
 pprUsage usage@UsageHomeModule{}
-  = hsep [ptext (sLit "import"), ppr (usg_mod_name usage), 
-	  ppr (usg_mod_hash usage)] $$
+  = pprUsageImport usage usg_mod_name $$
     nest 2 (
 	maybe empty (\v -> text "exports: " <> ppr v) (usg_exports usage) $$
         vcat [ ppr n <+> ppr v | (n,v) <- usg_entities usage ]
         )
 
+pprUsageImport :: Outputable a => Usage -> (Usage -> a) -> SDoc
+pprUsageImport usage usg_mod'
+  = hsep [ptext (sLit "import"), safe, ppr (usg_mod' usage),
+                       ppr (usg_mod_hash usage)]
+    where
+        safe | usg_safe usage = ptext $ sLit "safe"
+             | otherwise      = ptext $ sLit " -/ "
+
 pprDeps :: Dependencies -> SDoc
 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs,
 		dep_finsts = finsts })
diff --git a/compiler/iface/MkIface.lhs b/compiler/iface/MkIface.lhs
index 9deceb53b9..6ff91919c9 100644
--- a/compiler/iface/MkIface.lhs
+++ b/compiler/iface/MkIface.lhs
@@ -873,7 +873,8 @@ mk_usage_info pit hsc_env this_mod direct_imports used_names
 
       | modulePackageId mod /= this_pkg
       = Just UsagePackageModule{ usg_mod      = mod,
-                                 usg_mod_hash = mod_hash }
+                                 usg_mod_hash = mod_hash,
+                                 usg_safe     = imp_safe }
         -- for package modules, we record the module hash only
 
       | (null used_occs
@@ -888,22 +889,27 @@ mk_usage_info pit hsc_env this_mod direct_imports used_names
       | otherwise	
       = Just UsageHomeModule { 
                       usg_mod_name = moduleName mod,
-    	  	      usg_mod_hash = mod_hash,
-    		      usg_exports  = export_hash,
-    		      usg_entities = Map.toList ent_hashs }
+                      usg_mod_hash = mod_hash,
+                      usg_exports  = export_hash,
+                      usg_entities = Map.toList ent_hashs,
+                      usg_safe     = imp_safe }
       where
-	maybe_iface  = lookupIfaceByModule dflags hpt pit mod
-		-- In one-shot mode, the interfaces for home-package 
-		-- modules accumulate in the PIT not HPT.  Sigh.
-
-        is_direct_import = mod `elemModuleEnv` direct_imports
+        maybe_iface  = lookupIfaceByModule dflags hpt pit mod
+                -- In one-shot mode, the interfaces for home-package
+                -- modules accumulate in the PIT not HPT.  Sigh.
 
         Just iface   = maybe_iface
 	finsts_mod   = mi_finsts    iface
         hash_env     = mi_hash_fn   iface
         mod_hash     = mi_mod_hash  iface
         export_hash | depend_on_exports = Just (mi_exp_hash iface)
-    		    | otherwise         = Nothing
+                    | otherwise         = Nothing
+
+        (is_direct_import, imp_safe)
+            = case lookupModuleEnv direct_imports mod of
+                Just ((_,_,_,safe):xs) -> (True, safe)
+                Just _                 -> pprPanic "mkUsage: empty direct import" empty
+                Nothing                -> (False, False)
     
         used_occs = lookupModuleEnv ent_map mod `orElse` []
 
@@ -1158,7 +1164,7 @@ checkDependencies hsc_env summary iface
    orM = foldr f (return False)
     where f m rest = do b <- m; if b then return True else rest
 
-   dep_missing (L _ (ImportDecl (L _ mod) pkg _ _ _ _)) = do
+   dep_missing (L _ (ImportDecl (L _ mod) pkg _ _ _ _ _)) = do
      find_res <- liftIO $ findImportedModule hsc_env mod pkg
      case find_res of
         Found _ mod