cryptol-2.7.0: src/Cryptol/ModuleSystem/Renamer.hs
-- |
-- 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 #-}