X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Frename%2FRnBinds.lhs;fp=compiler%2Frename%2FRnBinds.lhs;h=6c57cb2aa887f2cd73e89d3be67491a832e5ea95;hp=0b107645f32dd6a7d7a490956ae939ed62047290;hb=41dc5190d5ffec988834fa055f407157c1e1022b;hpb=376bb624b0d66d4f2015ded40c46b3ea7a8263aa

diff --git a/compiler/rename/RnBinds.lhs b/compiler/rename/RnBinds.lhs
index 0b10764..6c57cb2 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: