-- | -- Module : Cryptol.ModuleSystem.Renamer -- Copyright : (c) 2013-2016 Galois, Inc. -- License : BSD3 -- Maintainer : cryptol@galois.com -- Stability : provisional -- Portability : portable {-# LANGUAGE DeriveAnyClass #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE MultiWayIf #-} {-# LANGUAGE PatternGuards #-} {-# LANGUAGE RecordWildCards #-} {-# LANGUAGE ViewPatterns #-} {-# LANGUAGE OverloadedStrings #-} module Cryptol.ModuleSystem.Renamer ( NamingEnv(), shadowing , BindsNames(..), InModule(..), namingEnv' , checkNamingEnv , shadowNames , Rename(..), runRenamer, RenameM() , RenamerError(..) , RenamerWarning(..) , renameVar , renameType , renameModule ) where import Cryptol.ModuleSystem.Name import Cryptol.ModuleSystem.NamingEnv import Cryptol.ModuleSystem.Exports import Cryptol.Prims.Syntax import Cryptol.Parser.AST import Cryptol.Parser.Position import Cryptol.Parser.Selector(ppNestedSels,selName) import Cryptol.TypeCheck.Type (TCon(..)) import Cryptol.Utils.Ident (packInfix) import Cryptol.Utils.Panic (panic) import Cryptol.Utils.PP import Data.List(find) import qualified Data.Foldable as F import Data.Map.Strict ( Map ) import qualified Data.Map.Strict as Map import qualified Data.Sequence as Seq import qualified Data.Semigroup as S import qualified Data.Set as Set import MonadLib hiding (mapM, mapM_) import GHC.Generics (Generic) import Control.DeepSeq import Prelude () import Prelude.Compat -- Errors ---------------------------------------------------------------------- data RenamerError = MultipleSyms (Located PName) [Name] NameDisp -- ^ Multiple imported symbols contain this name | UnboundExpr (Located PName) NameDisp -- ^ Expression name is not bound to any definition | UnboundType (Located PName) NameDisp -- ^ Type name is not bound to any definition | OverlappingSyms [Name] NameDisp -- ^ An environment has produced multiple overlapping symbols | ExpectedValue (Located PName) NameDisp -- ^ When a value is expected from the naming environment, but one or more -- types exist instead. | ExpectedType (Located PName) NameDisp -- ^ When a type is missing from the naming environment, but one or more -- values exist with the same name. | FixityError (Located Name) (Located Name) NameDisp -- ^ When the fixity of two operators conflict | InvalidConstraint (Type PName) NameDisp -- ^ When it's not possible to produce a Prop from a Type. | MalformedBuiltin (Type PName) PName NameDisp -- ^ When a builtin type/type-function is used incorrectly. | BoundReservedType PName (Maybe Range) Doc NameDisp -- ^ When a builtin type is named in a binder. | OverlappingRecordUpdate (Located [Selector]) (Located [Selector]) NameDisp -- ^ When record updates overlap (e.g., @{ r | x = e1, x.y = e2 }@) deriving (Show, Generic, NFData) instance PP RenamerError where ppPrec _ e = case e of MultipleSyms lqn qns disp -> fixNameDisp disp $ hang (text "[error] at" <+> pp (srcRange lqn)) 4 $ (text "Multiple definitions for symbol:" <+> pp (thing lqn)) $$ vcat (map ppLocName qns) UnboundExpr lqn disp -> fixNameDisp disp $ hang (text "[error] at" <+> pp (srcRange lqn)) 4 (text "Value not in scope:" <+> pp (thing lqn)) UnboundType lqn disp -> fixNameDisp disp $ hang (text "[error] at" <+> pp (srcRange lqn)) 4 (text "Type not in scope:" <+> pp (thing lqn)) OverlappingSyms qns disp -> fixNameDisp disp $ hang (text "[error]") 4 $ text "Overlapping symbols defined:" $$ vcat (map ppLocName qns) ExpectedValue lqn disp -> fixNameDisp disp $ hang (text "[error] at" <+> pp (srcRange lqn)) 4 (fsep [ text "Expected a value named", quotes (pp (thing lqn)) , text "but found a type instead" , text "Did you mean `(" <.> pp (thing lqn) <.> text")?" ]) ExpectedType lqn disp -> fixNameDisp disp $ hang (text "[error] at" <+> pp (srcRange lqn)) 4 (fsep [ text "Expected a type named", quotes (pp (thing lqn)) , text "but found a value instead" ]) FixityError o1 o2 disp -> fixNameDisp disp $ hang (text "[error]") 4 (fsep [ text "The fixities of", pp o1, text "and", pp o2 , text "are not compatible. " , text "You may use explicit parenthesis to disambiguate" ]) InvalidConstraint ty disp -> fixNameDisp disp $ hang (text "[error]" <+> maybe empty (\r -> text "at" <+> pp r) (getLoc ty)) 4 (fsep [ pp ty, text "is not a valid constraint" ]) MalformedBuiltin ty pn disp -> fixNameDisp disp $ hang (text "[error]" <+> maybe empty (\r -> text "at" <+> pp r) (getLoc ty)) 4 (fsep [ text "invalid use of built-in type", pp pn , text "in type", pp ty ]) BoundReservedType n loc src disp -> fixNameDisp disp $ hang (text "[error]" <+> maybe empty (\r -> text "at" <+> pp r) loc) 4 (fsep [ text "built-in type", quotes (pp n), text "shadowed in", src ]) OverlappingRecordUpdate xs ys disp -> fixNameDisp disp $ hang "[error] Overlapping record updates:" 4 (vcat [ ppLab xs, ppLab ys ]) where ppLab as = ppNestedSels (thing as) <+> "at" <+> pp (srcRange as) -- Warnings -------------------------------------------------------------------- data RenamerWarning = SymbolShadowed Name [Name] NameDisp | UnusedName Name NameDisp deriving (Show, Generic, NFData) instance PP RenamerWarning where ppPrec _ (SymbolShadowed new originals disp) = fixNameDisp disp $ hang (text "[warning] at" <+> loc) 4 $ fsep [ text "This binding for" <+> sym , (text "shadows the existing binding" <.> plural) <+> text "from" ] $$ vcat (map ppLocName originals) where plural | length originals > 1 = char 's' | otherwise = empty loc = pp (nameLoc new) sym = pp new ppPrec _ (UnusedName x disp) = fixNameDisp disp $ hang (text "[warning] at" <+> pp (nameLoc x)) 4 (text "Unused name:" <+> pp x) -- Renaming Monad -------------------------------------------------------------- data RO = RO { roLoc :: Range , roMod :: !ModName , roNames :: NamingEnv , roDisp :: !NameDisp } data RW = RW { rwWarnings :: !(Seq.Seq RenamerWarning) , rwErrors :: !(Seq.Seq RenamerError) , rwSupply :: !Supply , rwNameUseCount :: !(Map Name Int) -- ^ How many times did we refer to each name. -- Used to generate warnings for unused definitions. } newtype RenameM a = RenameM { unRenameM :: ReaderT RO (StateT RW Lift) a } instance S.Semigroup a => S.Semigroup (RenameM a) where {-# INLINE (<>) #-} a <> b = do x <- a y <- b return (x S.<> y) instance (S.Semigroup a, Monoid a) => Monoid (RenameM a) where {-# INLINE mempty #-} mempty = return mempty {-# INLINE mappend #-} mappend = (S.<>) instance Functor RenameM where {-# INLINE fmap #-} fmap f m = RenameM (fmap f (unRenameM m)) instance Applicative RenameM where {-# INLINE pure #-} pure x = RenameM (pure x) {-# INLINE (<*>) #-} l <*> r = RenameM (unRenameM l <*> unRenameM r) instance Monad RenameM where {-# INLINE return #-} return x = RenameM (return x) {-# INLINE (>>=) #-} m >>= k = RenameM (unRenameM m >>= unRenameM . k) instance FreshM RenameM where liftSupply f = RenameM $ sets $ \ RW { .. } -> let (a,s') = f rwSupply rw' = RW { rwSupply = s', .. } in a `seq` rw' `seq` (a, rw') runRenamer :: Supply -> ModName -> NamingEnv -> RenameM a -> (Either [RenamerError] (a,Supply),[RenamerWarning]) runRenamer s ns env m = (res, warnUnused ns env ro rw ++ F.toList (rwWarnings rw)) where (a,rw) = runM (unRenameM m) ro RW { rwErrors = Seq.empty , rwWarnings = Seq.empty , rwSupply = s , rwNameUseCount = Map.empty } ro = RO { roLoc = emptyRange , roNames = env , roMod = ns , roDisp = neverQualifyMod ns `mappend` toNameDisp env } res | Seq.null (rwErrors rw) = Right (a,rwSupply rw) | otherwise = Left (F.toList (rwErrors rw)) -- | Record an error. XXX: use a better name record :: (NameDisp -> RenamerError) -> RenameM () record f = RenameM $ do RO { .. } <- ask RW { .. } <- get set RW { rwErrors = rwErrors Seq.|> f roDisp, .. } -- | Get the source range for wahtever we are currently renaming. curLoc :: RenameM Range curLoc = RenameM (roLoc `fmap` ask) -- | Annotate something with the current range. located :: a -> RenameM (Located a) located thing = do srcRange <- curLoc return Located { .. } -- | Do the given computation using the source code range from `loc` if any. withLoc :: HasLoc loc => loc -> RenameM a -> RenameM a withLoc loc m = RenameM $ case getLoc loc of Just range -> do ro <- ask local ro { roLoc = range } (unRenameM m) Nothing -> unRenameM m -- | Retrieve the name of the current module. getNS :: RenameM ModName getNS = RenameM (roMod `fmap` ask) -- | Shadow the current naming environment with some more names. shadowNames :: BindsNames env => env -> RenameM a -> RenameM a shadowNames = shadowNames' CheckAll data EnvCheck = CheckAll -- ^ Check for overlap and shadowing | CheckOverlap -- ^ Only check for overlap | CheckNone -- ^ Don't check the environment deriving (Eq,Show) -- | Shadow the current naming environment with some more names. The boolean -- parameter indicates whether or not to check for shadowing. shadowNames' :: BindsNames env => EnvCheck -> env -> RenameM a -> RenameM a shadowNames' check names m = do do env <- liftSupply (namingEnv' names) RenameM $ do ro <- ask env' <- sets (checkEnv (roDisp ro) check env (roNames ro)) let ro' = ro { roNames = env' `shadowing` roNames ro } local ro' (unRenameM m) shadowNamesNS :: BindsNames (InModule env) => env -> RenameM a -> RenameM a shadowNamesNS names m = do ns <- getNS shadowNames (InModule ns names) m -- | Generate warnings when the left environment shadows things defined in -- the right. Additionally, generate errors when two names overlap in the -- left environment. checkEnv :: NameDisp -> EnvCheck -> NamingEnv -> NamingEnv -> RW -> (NamingEnv,RW) checkEnv disp check l r rw | check == CheckNone = (l',rw) | otherwise = (l',rw'') where l' = l { neExprs = es, neTypes = ts } (rw',es) = Map.mapAccumWithKey (step neExprs) rw (neExprs l) (rw'',ts) = Map.mapAccumWithKey (step neTypes) rw' (neTypes l) step prj acc k ns = (acc', [head ns]) where acc' = acc { rwWarnings = if check == CheckAll then case Map.lookup k (prj r) of Nothing -> rwWarnings acc Just os -> rwWarnings acc Seq.|> SymbolShadowed (head ns) os disp else rwWarnings acc , rwErrors = rwErrors acc Seq.>< containsOverlap disp ns } -- | Check the RHS of a single name rewrite for conflicting sources. containsOverlap :: NameDisp -> [Name] -> Seq.Seq RenamerError containsOverlap _ [_] = Seq.empty containsOverlap _ [] = panic "Renamer" ["Invalid naming environment"] containsOverlap disp ns = Seq.singleton (OverlappingSyms ns disp) -- | Throw errors for any names that overlap in a rewrite environment. checkNamingEnv :: NamingEnv -> ([RenamerError],[RenamerWarning]) checkNamingEnv env = (F.toList out, []) where out = Map.foldr check outTys (neExprs env) outTys = Map.foldr check mempty (neTypes env) disp = toNameDisp env check ns acc = containsOverlap disp ns Seq.>< acc recordUse :: Name -> RenameM () recordUse x = RenameM $ sets_ $ \rw -> rw { rwNameUseCount = Map.insertWith (+) x 1 (rwNameUseCount rw) } warnUnused :: ModName -> NamingEnv -> RO -> RW -> [RenamerWarning] warnUnused m0 env ro rw = map warn $ Map.keys $ Map.filterWithKey keep $ rwNameUseCount rw where warn x = UnusedName x (roDisp ro) keep k n = n == 1 && isLocal k oldNames = fst (visibleNames env) isLocal nm = case nameInfo nm of Declared m sys -> sys == UserName && m == m0 && nm `Set.notMember` oldNames Parameter -> True -- Renaming -------------------------------------------------------------------- class Rename f where rename :: f PName -> RenameM (f Name) renameModule :: Module PName -> RenameM (NamingEnv,Module Name) renameModule m = do env <- liftSupply (namingEnv' m) -- NOTE: we explicitly hide shadowing errors here, by using shadowNames' decls' <- shadowNames' CheckOverlap env (traverse rename (mDecls m)) let m1 = m { mDecls = decls' } exports = modExports m1 mapM_ recordUse (eTypes exports) return (env,m1) instance Rename TopDecl where rename td = case td of Decl d -> Decl <$> traverse rename d TDNewtype n -> TDNewtype <$> traverse rename n Include n -> return (Include n) DParameterFun f -> DParameterFun <$> rename f DParameterType f -> DParameterType <$> rename f DParameterConstraint d -> DParameterConstraint <$> mapM renameLocated d renameLocated :: Rename f => Located (f PName) -> RenameM (Located (f Name)) renameLocated x = do y <- rename (thing x) return x { thing = y } instance Rename ParameterType where rename a = do n' <- rnLocated renameType (ptName a) return a { ptName = n' } instance Rename ParameterFun where rename a = do n' <- rnLocated renameVar (pfName a) sig' <- renameSchema (pfSchema a) return a { pfName = n', pfSchema = snd sig' } rnLocated :: (a -> RenameM b) -> Located a -> RenameM (Located b) rnLocated f loc = withLoc loc $ do a' <- f (thing loc) return loc { thing = a' } instance Rename Decl where rename d = case d of DSignature ns sig -> DSignature <$> traverse (rnLocated renameVar) ns <*> rename sig DPragma ns p -> DPragma <$> traverse (rnLocated renameVar) ns <*> pure p DBind b -> DBind <$> rename b -- XXX we probably shouldn't see these at this point... DPatBind pat e -> do (pe,pat') <- renamePat pat shadowNames pe (DPatBind pat' <$> rename e) DType syn -> DType <$> rename syn DProp syn -> DProp <$> rename syn DLocated d' r -> withLoc r $ DLocated <$> rename d' <*> pure r DFixity{} -> panic "Renamer" ["Unexpected fixity declaration" , show d] instance Rename Newtype where rename n = do name' <- rnLocated renameType (nName n) shadowNames (nParams n) $ do ps' <- traverse rename (nParams n) body' <- traverse (rnNamed rename) (nBody n) return Newtype { nName = name' , nParams = ps' , nBody = body' } renameVar :: PName -> RenameM Name renameVar qn = do ro <- RenameM ask case Map.lookup qn (neExprs (roNames ro)) of Just [n] -> return n Just [] -> panic "Renamer" ["Invalid expression renaming environment"] Just syms -> do n <- located qn record (MultipleSyms n syms) return (head syms) -- This is an unbound value. Record an error and invent a bogus real name -- for it. Nothing -> do n <- located qn case Map.lookup qn (neTypes (roNames ro)) of -- types existed with the name of the value expected Just _ -> record (ExpectedValue n) -- the value is just missing Nothing -> record (UnboundExpr n) mkFakeName qn -- | Produce a name if one exists. Note that this includes situations where -- overlap exists, as it's just a query about anything being in scope. In the -- event that overlap does exist, an error will be recorded. typeExists :: PName -> RenameM (Maybe Name) typeExists pn = do ro <- RenameM ask case Map.lookup pn (neTypes (roNames ro)) of Just [n] -> recordUse n >> return (Just n) Just [] -> panic "Renamer" ["Invalid type renaming environment"] Just syms -> do n <- located pn mapM_ recordUse syms record (MultipleSyms n syms) return (Just (head syms)) Nothing -> return Nothing renameType :: PName -> RenameM Name renameType pn = do mb <- typeExists pn case mb of Just n -> return n -- This is an unbound value. Record an error and invent a bogus real name -- for it. Nothing -> do ro <- RenameM ask let n = Located { srcRange = roLoc ro, thing = pn } case Map.lookup pn (neExprs (roNames ro)) of -- values exist with the same name, so throw a different error Just _ -> record (ExpectedType n) -- no terms with the same name, so the type is just unbound Nothing -> record (UnboundType n) mkFakeName pn -- | Assuming an error has been recorded already, construct a fake name that's -- not expected to make it out of the renamer. mkFakeName :: PName -> RenameM Name mkFakeName pn = do ro <- RenameM ask liftSupply (mkParameter (getIdent pn) (roLoc ro)) -- | Rename a schema, assuming that none of its type variables are already in -- scope. instance Rename Schema where rename s = snd `fmap` renameSchema s -- | Rename a schema, assuming that the type variables have already been brought -- into scope. renameSchema :: Schema PName -> RenameM (NamingEnv,Schema Name) renameSchema (Forall ps p ty loc) = do -- check that the parameters don't shadow any built-in types let reserved = filter (isReserved . tpName) ps mkErr tp = BoundReservedType (tpName tp) (tpRange tp) (text "schema") unless (null reserved) (mapM_ (record . mkErr) reserved) env <- liftSupply (namingEnv' ps) s' <- shadowNames env $ Forall <$> traverse rename ps <*> traverse rename p <*> rename ty <*> pure loc return (env,s') instance Rename TParam where rename TParam { .. } = do n <- renameType tpName return TParam { tpName = n, .. } instance Rename Prop where rename p = case p of CFin t -> CFin <$> rename t CEqual l r -> CEqual <$> rename l <*> rename r CNeq l r -> CNeq <$> rename l <*> rename r CGeq l r -> CGeq <$> rename l <*> rename r CZero t -> CZero <$> rename t CLogic t -> CLogic <$> rename t CArith t -> CArith <$> rename t CCmp t -> CCmp <$> rename t CSignedCmp t -> CSignedCmp <$> rename t CLiteral l r -> CLiteral <$> rename l <*> rename r CUser qn ps -> CUser <$> renameType qn <*> traverse rename ps CLocated p' r -> withLoc r $ CLocated <$> rename p' <*> pure r -- here, we rename the type and then require that it produces something that -- looks like a Prop CType t -> translateProp =<< resolveTypeFixity t translateProp :: Type PName -> RenameM (Prop Name) translateProp ty = go ty where go t = case t of TLocated t' r -> (`CLocated` r) <$> go t' TApp (PC x) [l,r] | PEqual <- x -> CEqual <$> rename l <*> rename r | PNeq <- x -> CNeq <$> rename l <*> rename r | PGeq <- x -> CGeq <$> rename l <*> rename r TUser n [l,r] | isLeq n -> CGeq <$> rename r <*> rename l TUser n ts -> CUser <$> renameType n <*> traverse rename ts -- record an error, but continue renaming to gather any other errors _ -> do record (InvalidConstraint ty) CType <$> rename t -- | Check to see if this identifier is a reserved type/type-function. isReserved :: PName -> Bool isReserved pn = case primTyFromPName pn of Just _ -> True _ -> False -- | Resolve fixity, then rename the resulting type. instance Rename Type where rename ty0 = go =<< resolveTypeFixity ty0 where go :: Type PName -> RenameM (Type Name) go (TFun a b) = TFun <$> go a <*> go b go (TSeq n a) = TSeq <$> go n <*> go a go TBit = return TBit go (TNum c) = return (TNum c) go (TChar c) = return (TChar c) go (TUser pn ps) | Just pt <- primTyFromPName pn = do ps' <- traverse go ps return (TApp (primTyCon pt) ps') go (TUser qn ps) = TUser <$> renameType qn <*> traverse go ps go (TApp f xs) = TApp f <$> traverse go xs go (TRecord fs) = TRecord <$> traverse (rnNamed go) fs go (TTuple fs) = TTuple <$> traverse go fs go TWild = return TWild go (TLocated t' r) = withLoc r (TLocated <$> go t' <*> pure r) go (TParens t') = TParens <$> go t' -- at this point, the fixity is correct, and we just need to perform -- renaming. go (TInfix a o f b) = TInfix <$> rename a <*> rnLocated renameType o <*> pure f <*> rename b resolveTypeFixity :: Type PName -> RenameM (Type PName) resolveTypeFixity = go where go t = case t of TFun a b -> TFun <$> go a <*> go b TSeq n a -> TSeq <$> go n <*> go a TUser pn ps -> TUser pn <$> traverse go ps TApp f xs -> TApp f <$> traverse go xs TRecord fs -> TRecord <$> traverse (traverse go) fs TTuple fs -> TTuple <$> traverse go fs TLocated t' r-> withLoc r (TLocated <$> go t' <*> pure r) TParens t' -> TParens <$> go t' TInfix a o _ b -> do let op = lookupFixity o a' <- go a b' <- go b mkTInfix a' op b' TBit -> return t TNum _ -> return t TChar _ -> return t TWild -> return t type TOp = Type PName -> Type PName -> Type PName mkTInfix :: Type PName -> (TOp,Fixity) -> Type PName -> RenameM (Type PName) mkTInfix t op@(o2,f2) z = case t of TLocated t1 _ -> mkTInfix t1 op z TUser op1 [x,y] | isLeq op1 -> doFixity (TUser op1) leqFixity x y TApp tc [x,y] | Just pt <- primTyFromTC tc , Just f1 <- primTyFixity pt -> doFixity (TApp tc) f1 x y _ -> return (o2 t z) where doFixity mk f1 x y = case compareFixity f1 f2 of FCLeft -> return (o2 t z) FCRight -> do r <- mkTInfix y op z return (mk [x,r]) -- As the fixity table is known, and this is a case where the fixity came -- from that table, it's a real error if the fixities didn't work out. FCError -> panic "Renamer" [ "fixity problem for type operators" , show (o2 t z) ] -- | When possible, rewrite the type operator to a known constructor, otherwise -- return a 'TOp' that reconstructs the original term, and a default fixity. lookupFixity :: Located PName -> (TOp,Fixity) lookupFixity op = case lkp of Just res -> res -- unknown type operator, just use default fixity -- NOTE: this works for the props defined above, as all other operators -- are defined with a higher precedence. Nothing -> (\x y -> TUser sym [x,y], Fixity NonAssoc 0) where sym = thing op lkp = do pt <- primTyFromPName (thing op) fi <- primTyFixity pt return (\x y -> TApp (primTyCon pt) [x,y], fi) `mplus` do guard (isLeq sym) return (\x y -> TUser sym [x,y], leqFixity) leqFixity :: Fixity leqFixity = Fixity NonAssoc 30 leqIdent :: Ident leqIdent = packInfix "<=" isLeq :: PName -> Bool isLeq x = getIdent x == leqIdent -- | Rename a binding. instance Rename Bind where rename b = do n' <- rnLocated renameVar (bName b) mbSig <- traverse renameSchema (bSignature b) shadowNames (fst `fmap` mbSig) $ do (patEnv,pats') <- renamePats (bParams b) -- NOTE: renamePats will generate warnings, so we don't need to trigger -- them again here. e' <- shadowNames' CheckNone patEnv (rnLocated rename (bDef b)) return b { bName = n' , bParams = pats' , bDef = e' , bSignature = snd `fmap` mbSig , bPragmas = bPragmas b } instance Rename BindDef where rename DPrim = return DPrim rename (DExpr e) = DExpr <$> rename e -- NOTE: this only renames types within the pattern. instance Rename Pattern where rename p = case p of PVar lv -> PVar <$> rnLocated renameVar lv PWild -> pure PWild PTuple ps -> PTuple <$> traverse rename ps PRecord nps -> PRecord <$> traverse (rnNamed rename) nps PList elems -> PList <$> traverse rename elems PTyped p' t -> PTyped <$> rename p' <*> rename t PSplit l r -> PSplit <$> rename l <*> rename r PLocated p' loc -> withLoc loc $ PLocated <$> rename p' <*> pure loc -- | Note that after this point the @->@ updates have an explicit funciton -- and there are no more nested updates. instance Rename UpdField where rename (UpdField h ls e) = -- The plan: -- x = e ~~~> x = e -- x -> e ~~~> x -> \x -> e -- x.y = e ~~~> x -> { _ | y = e } -- x.y -> e ~~~> x -> { _ | y -> e } case ls of l : more -> case more of [] -> case h of UpdSet -> UpdField UpdSet [l] <$> rename e UpdFun -> UpdField UpdFun [l] <$> rename (EFun [PVar p] e) where p = UnQual . selName <$> last ls _ -> UpdField UpdFun [l] <$> rename (EUpd Nothing [ UpdField h more e]) [] -> panic "rename@UpdField" [ "Empty label list." ] instance Rename Expr where rename expr = case expr of EVar n -> EVar <$> renameVar n ELit l -> return (ELit l) ENeg e -> ENeg <$> rename e EComplement e -> EComplement <$> rename e ETuple es -> ETuple <$> traverse rename es ERecord fs -> ERecord <$> traverse (rnNamed rename) fs ESel e' s -> ESel <$> rename e' <*> pure s EUpd mb fs -> do checkLabels fs EUpd <$> traverse rename mb <*> traverse rename fs EList es -> EList <$> traverse rename es EFromTo s n e'-> EFromTo <$> rename s <*> traverse rename n <*> rename e' EInfFrom a b -> EInfFrom<$> rename a <*> traverse rename b EComp e' bs -> do arms' <- traverse renameArm bs let (envs,bs') = unzip arms' -- NOTE: renameArm will generate shadowing warnings; we only -- need to check for repeated names across multiple arms shadowNames' CheckOverlap envs (EComp <$> rename e' <*> pure bs') EApp f x -> EApp <$> rename f <*> rename x EAppT f ti -> EAppT <$> rename f <*> traverse rename ti EIf b t f -> EIf <$> rename b <*> rename t <*> rename f EWhere e' ds -> do ns <- getNS shadowNames (map (InModule ns) ds) $ EWhere <$> rename e' <*> traverse rename ds ETyped e' ty -> ETyped <$> rename e' <*> rename ty ETypeVal ty -> ETypeVal<$> rename ty EFun ps e' -> do (env,ps') <- renamePats ps -- NOTE: renamePats will generate warnings, so we don't -- need to duplicate them here shadowNames' CheckNone env (EFun ps' <$> rename e') ELocated e' r -> withLoc r $ ELocated <$> rename e' <*> pure r ESplit e -> ESplit <$> rename e EParens p -> EParens <$> rename p EInfix x y _ z-> do op <- renameOp y x' <- rename x z' <- rename z mkEInfix x' op z' checkLabels :: [UpdField PName] -> RenameM () checkLabels = foldM_ check [] . map labs where labs (UpdField _ ls _) = ls check done l = do case find (overlap l) done of Just l' -> record (OverlappingRecordUpdate (reLoc l) (reLoc l')) Nothing -> pure () pure (l : done) overlap xs ys = case (xs,ys) of ([],_) -> True (_, []) -> True (x : xs', y : ys') -> same x y && overlap xs' ys' same x y = case (thing x, thing y) of (TupleSel a _, TupleSel b _) -> a == b (ListSel a _, ListSel b _) -> a == b (RecordSel a _, RecordSel b _) -> a == b _ -> False reLoc xs = (head xs) { thing = map thing xs } mkEInfix :: Expr Name -- ^ May contain infix expressions -> (Located Name,Fixity) -- ^ The operator to use -> Expr Name -- ^ Will not contain infix expressions -> RenameM (Expr Name) mkEInfix e@(EInfix x o1 f1 y) op@(o2,f2) z = case compareFixity f1 f2 of FCLeft -> return (EInfix e o2 f2 z) FCRight -> do r <- mkEInfix y op z return (EInfix x o1 f1 r) FCError -> do record (FixityError o1 o2) return (EInfix e o2 f2 z) mkEInfix (ELocated e' _) op z = mkEInfix e' op z mkEInfix e (o,f) z = return (EInfix e o f z) renameOp :: Located PName -> RenameM (Located Name,Fixity) renameOp ln = withLoc ln $ do n <- renameVar (thing ln) ro <- RenameM ask case Map.lookup n (neFixity (roNames ro)) of Just fixity -> return (ln { thing = n },fixity) Nothing -> return (ln { thing = n },defaultFixity) instance Rename TypeInst where rename ti = case ti of NamedInst nty -> NamedInst <$> traverse rename nty PosInst ty -> PosInst <$> rename ty renameArm :: [Match PName] -> RenameM (NamingEnv,[Match Name]) renameArm (m:ms) = do (me,m') <- renameMatch m -- NOTE: renameMatch will generate warnings, so we don't -- need to duplicate them here shadowNames' CheckNone me $ do (env,rest) <- renameArm ms -- NOTE: the inner environment shadows the outer one, for examples -- like this: -- -- [ x | x <- xs, let x = 10 ] return (env `shadowing` me, m':rest) renameArm [] = return (mempty,[]) -- | The name environment generated by a single match. renameMatch :: Match PName -> RenameM (NamingEnv,Match Name) renameMatch (Match p e) = do (pe,p') <- renamePat p e' <- rename e return (pe,Match p' e') renameMatch (MatchLet b) = do ns <- getNS be <- liftSupply (namingEnv' (InModule ns b)) b' <- shadowNames be (rename b) return (be,MatchLet b') -- | Rename patterns, and collect the new environment that they introduce. renamePat :: Pattern PName -> RenameM (NamingEnv, Pattern Name) renamePat p = do pe <- patternEnv p p' <- shadowNames pe (rename p) return (pe, p') -- | Rename patterns, and collect the new environment that they introduce. renamePats :: [Pattern PName] -> RenameM (NamingEnv,[Pattern Name]) renamePats = loop where loop ps = case ps of p:rest -> do pe <- patternEnv p shadowNames pe $ do p' <- rename p (env',rest') <- loop rest return (pe `mappend` env', p':rest') [] -> return (mempty, []) patternEnv :: Pattern PName -> RenameM NamingEnv patternEnv = go where go (PVar Located { .. }) = do n <- liftSupply (mkParameter (getIdent thing) srcRange) return (singletonE thing n) go PWild = return mempty go (PTuple ps) = bindVars ps go (PRecord fs) = bindVars (map value fs) go (PList ps) = foldMap go ps go (PTyped p ty) = go p `mappend` typeEnv ty go (PSplit a b) = go a `mappend` go b go (PLocated p loc) = withLoc loc (go p) bindVars [] = return mempty bindVars (p:ps) = do env <- go p shadowNames env $ do rest <- bindVars ps return (env `mappend` rest) typeEnv (TFun a b) = bindTypes [a,b] typeEnv (TSeq a b) = bindTypes [a,b] typeEnv TBit = return mempty typeEnv TNum{} = return mempty typeEnv TChar{} = return mempty typeEnv (TUser pn ps) = do mb <- typeExists pn case mb of -- The type is already bound, don't introduce anything. Just _ -> bindTypes ps Nothing -- Just ignore reserved names, as they'll be resolved when renaming. | isReserved pn -> bindTypes ps -- The type isn't bound, and has no parameters, so it names a portion -- of the type of the pattern. | null ps -> do loc <- curLoc n <- liftSupply (mkParameter (getIdent pn) loc) return (singletonT pn n) -- This references a type synonym that's not in scope. Record an -- error and continue with a made up name. | otherwise -> do loc <- curLoc record (UnboundType (Located loc pn)) n <- liftSupply (mkParameter (getIdent pn) loc) return (singletonT pn n) typeEnv (TApp _ ts) = bindTypes ts typeEnv (TRecord fs) = bindTypes (map value fs) typeEnv (TTuple ts) = bindTypes ts typeEnv TWild = return mempty typeEnv (TLocated ty loc) = withLoc loc (typeEnv ty) typeEnv (TParens ty) = typeEnv ty typeEnv (TInfix a _ _ b) = bindTypes [a,b] bindTypes [] = return mempty bindTypes (t:ts) = do env' <- typeEnv t shadowNames env' $ do res <- bindTypes ts return (env' `mappend` res) instance Rename Match where rename m = case m of Match p e -> Match <$> rename p <*> rename e MatchLet b -> shadowNamesNS b (MatchLet <$> rename b) instance Rename TySyn where rename (TySyn n ps ty) = do when (isReserved (thing n)) (record (BoundReservedType (thing n) (getLoc n) (text "type synonym"))) shadowNames ps $ TySyn <$> rnLocated renameType n <*> traverse rename ps <*> rename ty instance Rename PropSyn where rename (PropSyn n ps cs) = do when (isReserved (thing n)) (record (BoundReservedType (thing n) (getLoc n) (text "constraint synonym"))) shadowNames ps $ PropSyn <$> rnLocated renameType n <*> traverse rename ps <*> traverse rename cs -- Utilities ------------------------------------------------------------------- rnNamed :: (a -> RenameM b) -> Named a -> RenameM (Named b) rnNamed = traverse {-# INLINE rnNamed #-}