nlHsDo, nlHsOpApp, nlHsLam, nlHsPar, nlHsIf, nlHsCase, nlList,
mkLHsTupleExpr, mkLHsVarTuple, missingTupArg,
- -- Bindigns
+ -- Bindings
mkFunBind, mkVarBind, mkHsVarBind, mk_easy_FunBind,
-- Literals
collectSigTysFromPats, collectSigTysFromPat,
hsTyClDeclBinders, hsTyClDeclsBinders,
- hsForeignDeclsBinders, hsGroupBinders
+ hsForeignDeclsBinders, hsGroupBinders,
+
+ -- Collecting implicit binders
+ lStmtsImplicits, hsValBindsImplicits, lPatImplicits
) where
import HsDecls
import BasicTypes
import SrcLoc
import FastString
+ import Outputable
import Util
import Bag
+
+ import Data.Either
\end{code}
%************************************************************************
%* *
+ Collecting binders the user did not write
+ %* *
+ %************************************************************************
+
+ The job of this family of functions is to run through binding sites and find the set of all Names
+ that were defined "implicitly", without being explicitly written by the user.
+
+ The main purpose is to find names introduced by record wildcards so that we can avoid
+ warning the user when they don't use those names (#4404)
+
+ \begin{code}
+ lStmtsImplicits :: [LStmtLR Name idR] -> NameSet
+ lStmtsImplicits = hs_lstmts
+ where
+ hs_lstmts :: [LStmtLR Name idR] -> NameSet
+ hs_lstmts = foldr (\stmt rest -> unionNameSets (hs_stmt (unLoc stmt)) rest) emptyNameSet
+
+ hs_stmt (BindStmt pat _ _ _) = lPatImplicits pat
+ hs_stmt (LetStmt binds) = hs_local_binds binds
+ hs_stmt (ExprStmt _ _ _) = emptyNameSet
+ hs_stmt (ParStmt xs) = hs_lstmts $ concatMap fst xs
+
+ hs_stmt (TransformStmt stmts _ _ _) = hs_lstmts stmts
+ hs_stmt (GroupStmt stmts _ _ _) = hs_lstmts stmts
+ hs_stmt (RecStmt { recS_stmts = ss }) = hs_lstmts ss
+
+ hs_local_binds (HsValBinds val_binds) = hsValBindsImplicits val_binds
+ hs_local_binds (HsIPBinds _) = emptyNameSet
+ hs_local_binds EmptyLocalBinds = emptyNameSet
+
+ hsValBindsImplicits :: HsValBindsLR Name idR -> NameSet
+ hsValBindsImplicits (ValBindsOut binds _)
+ = unionManyNameSets [foldBag unionNameSets (hs_bind . unLoc) emptyNameSet hs_binds | (_rec, hs_binds) <- binds]
+ where
+ hs_bind (PatBind { pat_lhs = lpat }) = lPatImplicits lpat
+ hs_bind _ = emptyNameSet
+ hsValBindsImplicits (ValBindsIn {}) = pprPanic "hsValBindsImplicits: ValBindsIn" empty
+
+ lPatImplicits :: LPat Name -> NameSet
+ lPatImplicits = hs_lpat
+ where
+ hs_lpat (L _ pat) = hs_pat pat
+
+ hs_lpats = foldr (\pat rest -> hs_lpat pat `unionNameSets` rest) emptyNameSet
+
+ hs_pat (LazyPat pat) = hs_lpat pat
+ hs_pat (BangPat pat) = hs_lpat pat
+ hs_pat (AsPat _ pat) = hs_lpat pat
+ hs_pat (ViewPat _ pat _) = hs_lpat pat
+ hs_pat (ParPat pat) = hs_lpat pat
+ hs_pat (ListPat pats _) = hs_lpats pats
+ hs_pat (PArrPat pats _) = hs_lpats pats
+ hs_pat (TuplePat pats _ _) = hs_lpats pats
+
+ hs_pat (SigPatIn pat _) = hs_lpat pat
+ hs_pat (SigPatOut pat _) = hs_lpat pat
+ hs_pat (CoPat _ pat _) = hs_pat pat
+
+ hs_pat (ConPatIn _ ps) = details ps
+ hs_pat (ConPatOut {pat_args=ps}) = details ps
+
+ hs_pat _ = emptyNameSet
+
+ details (PrefixCon ps) = hs_lpats ps
+ details (RecCon fs) = hs_lpats explicit `unionNameSets` mkNameSet (collectPatsBinders implicit)
+ where (explicit, implicit) = partitionEithers [if pat_explicit then Left pat else Right pat
+ | (i, fld) <- [0..] `zip` rec_flds fs
+ , let pat = hsRecFieldArg fld
+ pat_explicit = maybe True (i<) (rec_dotdot fs)]
+ details (InfixCon p1 p2) = hs_lpat p1 `unionNameSets` hs_lpat p2
+ \end{code}
+
+
+ %************************************************************************
+ %* *
Collecting type signatures from patterns
%* *
%************************************************************************
-- 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) }
#ifdef GHCI
tcRnStmt, tcRnExpr, tcRnType,
tcRnLookupRdrName,
- getModuleExports,
+ getModuleExports,
#endif
+ tcRnImports,
tcRnLookupName,
tcRnGetInfo,
tcRnModule,
-- any mutually recursive types are done right
-- Just discard the auxiliary bindings; they are generated
-- only for Haskell source code, and should already be in Core
- (tcg_env, _aux_binds, _dm_ids) <- tcTyAndClassDecls emptyModDetails rn_decls ;
+ (tcg_env, _aux_binds, _dm_ids, _) <- tcTyAndClassDecls emptyModDetails rn_decls ;
setGblEnv tcg_env $ do {
-- Make the new type env available to stuff slurped from interface files
-- Typecheck type/class decls
; traceTc "Tc2" empty
- ; (tcg_env, aux_binds, dm_ids)
+ ; (tcg_env, aux_binds, dm_ids, _)
<- tcTyAndClassDecls emptyModDetails tycl_decls
; setGblEnv tcg_env $
tcExtendIdEnv dm_ids $ do {
-- The latter come in via tycl_decls
traceTc "Tc2" empty ;
- (tcg_env, aux_binds, dm_ids) <- tcTyAndClassDecls boot_details tycl_decls ;
+ (tcg_env, aux_binds, dm_ids, kc_decls) <- tcTyAndClassDecls boot_details tycl_decls ;
-- If there are any errors, tcTyAndClassDecls fails here
setGblEnv tcg_env $
setLclTypeEnv tcl_env $ do { -- Environment doesn't change now
-- Second pass over class and instance declarations,
+ -- now using the kind-checked decls
traceTc "Tc6" empty ;
- inst_binds <- tcInstDecls2 (concat tycl_decls) inst_infos ;
+ inst_binds <- tcInstDecls2 kc_decls inst_infos ;
-- Foreign exports
traceTc "Tc7" empty ;
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