-- 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:
-> RnM (LHsBinds Name, FreeVars)
rnMethodBinds cls sig_fn gen_tyvars binds
- = foldlM do_one (emptyBag,emptyFVs) (bagToList binds)
+ = do { checkDupRdrNames meth_names
+ -- Check that the same method is not given twice in the
+ -- same instance decl instance C T where
+ -- f x = ...
+ -- g y = ...
+ -- f x = ...
+ -- We must use checkDupRdrNames because the Name of the
+ -- method is the Name of the class selector, whose SrcSpan
+ -- points to the class declaration; and we use rnMethodBinds
+ -- for instance decls too
+
+ ; foldlM do_one (emptyBag, emptyFVs) (bagToList binds) }
where
+ meth_names = collectMethodBinders binds
do_one (binds,fvs) bind
= do { (bind', fvs_bind) <- rnMethodBind cls sig_fn gen_tyvars bind
; return (binds `unionBags` bind', fvs_bind `plusFV` fvs) }
-- Check for duplicates on RdrName version,
-- because renamed version has unboundName for
-- not-in-scope binders, which gives bogus dup-sig errors
-
+ -- NB: in a class decl, a 'generic' sig is not considered
+ -- equal to an ordinary sig, so we allow, say
+ -- class C a where
+ -- op :: a -> a
+ -- generic op :: Eq a => a -> a
+
; sigs' <- mapM (wrapLocM (renameSig mb_names)) sigs
; let (good_sigs, bad_sigs) = partition (ok_sig . unLoc) sigs'
; new_ty <- rnHsSigType (quotes (ppr v)) ty
; return (TypeSig new_v new_ty) }
+renameSig mb_names sig@(GenericSig v ty)
+ = do { new_v <- lookupSigOccRn mb_names sig v
+ ; new_ty <- rnHsSigType (quotes (ppr v)) ty
+ ; return (GenericSig new_v new_ty) } -- JPM: ?
+
renameSig _ (SpecInstSig ty)
= do { new_ty <- rnLHsType (text "A SPECIALISE instance pragma") ty
; return (SpecInstSig new_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
rnGRHS' :: HsMatchContext Name -> GRHS RdrName -> RnM (GRHS Name, FreeVars)
rnGRHS' ctxt (GRHS guards rhs)
= do { pattern_guards_allowed <- xoptM Opt_PatternGuards
- ; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) guards $
+ ; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) guards $ \ _ ->
rnLExpr rhs
; unless (pattern_guards_allowed || is_standard_guard guards')