X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=compiler%2Frename%2FRnBinds.lhs;h=df3b12d1bbcb26086fd3856d43a5624eb14d511b;hb=1851bb3cb6b5e9f0d413da7afc9b58c768888ecf;hp=0b107645f32dd6a7d7a490956ae939ed62047290;hpb=ba05282d3915e7051b3f016366b971a8506b0093;p=ghc-hetmet.git

diff --git a/compiler/rename/RnBinds.lhs b/compiler/rename/RnBinds.lhs
index 0b10764..df3b12d 100644
--- a/compiler/rename/RnBinds.lhs
+++ b/compiler/rename/RnBinds.lhs
@@ -306,7 +306,10 @@ rnValBindsRHS trim mb_bound_names (ValBindsIn mbinds sigs)
            (anal_binds, anal_dus) -> return (valbind', valbind'_dus)
               where
                 valbind' = ValBindsOut anal_binds sigs'
-                valbind'_dus = usesOnly (hsSigsFVs sigs') `plusDU` anal_dus
+                valbind'_dus = anal_dus `plusDU` usesOnly (hsSigsFVs sigs')
+			       -- Put the sig uses *after* the bindings
+			       -- so that the binders are removed from 
+			       -- the uses in the sigs
        }
 
 rnValBindsRHS _ _ b = pprPanic "rnValBindsRHS" (ppr b)
@@ -357,7 +360,9 @@ rnLocalValBindsAndThen binds@(ValBindsIn _ sigs) thing_inside
 		-- 	let x = x in 3
 		-- should report 'x' unused
 	; let real_uses = findUses dus result_fvs
-	; warnUnusedLocalBinds bound_names real_uses
+	      -- Insert fake uses for variables introduced implicitly by wildcards (#4404)
+	      implicit_uses = hsValBindsImplicits binds'
+	; warnUnusedLocalBinds bound_names (real_uses `unionNameSets` implicit_uses)
 
 	; let
             -- The variables "used" in the val binds are: 
@@ -697,7 +702,7 @@ renameSig _ (SpecInstSig ty)
 -- {-# SPECIALISE #-} pragmas can refer to imported Ids
 -- so, in the top-level case (when mb_names is Nothing)
 -- we use lookupOccRn.  If there's both an imported and a local 'f'
--- then the SPECIALISE pragma is ambiguous, unlike alll other signatures
+-- then the SPECIALISE pragma is ambiguous, unlike all other signatures
 renameSig mb_names sig@(SpecSig v ty inl)
   = do	{ new_v <- case mb_names of
                      Just {} -> lookupSigOccRn mb_names sig v