SafeHaskell: Fix recompilation avoidance to take Safe into account.

compiler/iface/IfaceSyn.lhs

@@ -341,7 +341,7 @@ and suppose we are compiling module X:
         data T = ...
         instance C S T where ...
 
-If we base the instance verion on T, I'm worried that changing S to S'
+If we base the instance version on T, I'm worried that changing S to S'
 would change T's version, but not S or S'.  But an importing module might
 not depend on T, and so might not be recompiled even though the new instance
 (C S' T) might be relevant.  I have not been able to make a concrete example,

compiler/iface/MkIface.lhs

@@ -298,8 +298,6 @@ mkIface_ hsc_env maybe_old_fingerprint
             then return ( errs_and_warns, Nothing )
             else do {
 
--- XXX	; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
-   
 	   	-- Debug printing
 	; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE" 
 			(pprModIface new_iface)
@@ -520,9 +518,13 @@ addFingerprints hsc_env mb_old_fingerprint iface0 new_decls
                       (mi_exports iface0,
                        orphan_hash,
                        dep_orphan_hashes,
-                       dep_pkgs (mi_deps iface0))
+                       dep_pkgs (mi_deps iface0),
                         -- dep_pkgs: see "Package Version Changes" on
                         -- wiki/Commentary/Compiler/RecompilationAvoidance
+                       mi_trust iface0)
+                        -- TODO: Can probably make more fine grained. Only
+                        -- really need to have recompilation for overlapping
+                        -- instances.
 
    -- put the declarations in a canonical order, sorted by OccName
    let sorted_decls = Map.elems $ Map.fromList $

compiler/utils/Binary.hs

@@ -435,6 +435,15 @@ instance (Binary a, Binary b, Binary c, Binary d) => Binary (a,b,c,d) where
                          d <- get bh
                          return (a,b,c,d)
 
+instance (Binary a, Binary b, Binary c, Binary d, Binary e) => Binary (a,b,c,d, e) where
+    put_ bh (a,b,c,d, e) = do put_ bh a; put_ bh b; put_ bh c; put_ bh d; put_ bh e;
+    get bh          = do a <- get bh
+                         b <- get bh
+                         c <- get bh
+                         d <- get bh
+                         e <- get bh
+                         return (a,b,c,d,e)
+
 instance Binary a => Binary (Maybe a) where
     put_ bh Nothing  = putByte bh 0
     put_ bh (Just a) = do putByte bh 1; put_ bh a