X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Frename%2FRnBinds.lhs;h=503953d4a0cb47ceb2eb325810ce31a0b03e2da5;hp=0b107645f32dd6a7d7a490956ae939ed62047290;hb=fdf8656855d26105ff36bdd24d41827b05037b91;hpb=ba05282d3915e7051b3f016366b971a8506b0093

diff --git a/compiler/rename/RnBinds.lhs b/compiler/rename/RnBinds.lhs
index 0b10764..503953d 100644
--- a/compiler/rename/RnBinds.lhs
+++ b/compiler/rename/RnBinds.lhs
@@ -357,7 +357,9 @@ 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: 
@@ -453,7 +455,7 @@ rnBind :: (Name -> [Name])		-- Signature tyvar function
 rnBind _ trim (L loc bind@(PatBind { pat_lhs = pat
                                    , pat_rhs = grhss 
                                       -- pat fvs were stored in bind_fvs
-                                      -- after processing the LHS          
+                                      -- after processing the LHS
                                    , bind_fvs = pat_fvs }))
   = setSrcSpan loc $ 
     do	{ let bndrs = collectPatBinders pat
@@ -473,7 +475,7 @@ rnBind sig_fn trim
                             , fun_infix = is_infix 
                             , fun_matches = matches })) 
        -- invariant: no free vars here when it's a FunBind
-  = setSrcSpan loc $ 
+  = setSrcSpan loc $
     do	{ let plain_name = unLoc name
 
 	; (matches', fvs) <- bindSigTyVarsFV (sig_fn plain_name) $