\begin{code}
module TcMonad(
- TcM(..), NF_TcM(..), TcDown, TcEnv,
- SST_R, FSST_R,
+ TcM, NF_TcM, TcDown, TcEnv,
initTc,
- returnTc, thenTc, thenTc_, mapTc, listTc,
+ returnTc, thenTc, thenTc_, mapTc, mapTc_, listTc,
foldrTc, foldlTc, mapAndUnzipTc, mapAndUnzip3Tc,
- mapBagTc, fixTc, tryTc,
+ mapBagTc, fixTc, tryTc, tryTc_, getErrsTc,
+ traceTc, ioToTc,
+
+ uniqSMToTcM,
returnNF_Tc, thenNF_Tc, thenNF_Tc_, mapNF_Tc,
+ fixNF_Tc, forkNF_Tc, foldrNF_Tc, foldlNF_Tc,
+
listNF_Tc, mapAndUnzipNF_Tc, mapBagNF_Tc,
checkTc, checkTcM, checkMaybeTc, checkMaybeTcM,
- failTc, warnTc, recoverTc, recoverNF_Tc,
+ failTc, failWithTc, addErrTc, addErrsTc, warnTc,
+ recoverTc, checkNoErrsTc, recoverNF_Tc, discardErrsTc,
+ addErrTcM, addInstErrTcM, failWithTcM,
tcGetEnv, tcSetEnv,
tcGetDefaultTys, tcSetDefaultTys,
- tcGetUnique, tcGetUniques,
+ tcGetUnique, tcGetUniques,
+ doptsTc, getDOptsTc,
- tcAddSrcLoc, tcGetSrcLoc,
+ tcAddSrcLoc, tcGetSrcLoc, tcGetInstLoc,
tcAddErrCtxtM, tcSetErrCtxtM,
- tcAddErrCtxt, tcSetErrCtxt,
+ tcAddErrCtxt, tcSetErrCtxt, tcPopErrCtxt,
- tcNewMutVar, tcReadMutVar, tcWriteMutVar,
+ tcNewMutVar, tcReadMutVar, tcWriteMutVar, TcRef,
+ tcNewMutTyVar, tcReadMutTyVar, tcWriteMutTyVar,
- rn4MtoTcM,
+ InstOrigin(..), InstLoc, pprInstLoc,
- -- For closure
- MutableVar(..), _MutableArray
+ TcError, TcWarning, TidyEnv, emptyTidyEnv,
+ arityErr
) where
+#include "HsVersions.h"
-import TcMLoop ( TcEnv, initEnv, TcMaybe ) -- We need the type TcEnv and an initial Env
+import {-# SOURCE #-} TcEnv ( TcEnv )
-import Type ( Type(..), GenType )
-import TyVar ( TyVar(..), GenTyVar )
-import Usage ( Usage(..), GenUsage )
-import ErrUtils ( Error(..), Message(..), ErrCtxt(..),
- TcWarning(..), TcError(..), mkTcErr )
-
-import SST
-import RnMonad4
-import RnUtils ( GlobalNameMappers(..), GlobalNameMapper(..) )
+import HsLit ( HsOverLit )
+import RnHsSyn ( RenamedPat, RenamedArithSeqInfo, RenamedHsExpr )
+import TcType ( Type, Kind, TyVarDetails )
+import ErrUtils ( addShortErrLocLine, addShortWarnLocLine, ErrMsg, Message, WarnMsg )
import Bag ( Bag, emptyBag, isEmptyBag,
foldBag, unitBag, unionBags, snocBag )
-import FiniteMap ( FiniteMap, emptyFM )
-import Pretty ( Pretty(..), PrettyRep )
-import PprStyle ( PprStyle )
-import Outputable ( Outputable(..), NamedThing(..), ExportFlag )
-import Maybes ( MaybeErr(..) )
+import Class ( Class )
import Name ( Name )
-import ProtoName ( ProtoName )
-import SrcLoc ( SrcLoc, mkUnknownSrcLoc )
-import UniqFM ( UniqFM, emptyUFM )
-import UniqSupply ( UniqSupply, getUnique, getUniques, splitUniqSupply )
+import Var ( Id, TyVar, newMutTyVar, readMutTyVar, writeMutTyVar )
+import VarEnv ( TidyEnv, emptyTidyEnv )
+import UniqSupply ( UniqSupply, uniqFromSupply, uniqsFromSupply,
+ splitUniqSupply, mkSplitUniqSupply,
+ UniqSM, initUs_ )
+import SrcLoc ( SrcLoc, noSrcLoc )
+import BasicTypes ( IPName )
+import UniqFM ( emptyUFM )
import Unique ( Unique )
-import Util
+import CmdLineOpts
+import Outputable
+
+import IOExts ( IORef, newIORef, readIORef, writeIORef,
+ unsafeInterleaveIO, fixIO
+ )
+
infixr 9 `thenTc`, `thenTc_`, `thenNF_Tc`, `thenNF_Tc_`
\end{code}
-\section{TcM, NF_TcM: the type checker monads}
-%~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{The main monads: TcM, NF_TcM}
+%* *
+%************************************************************************
\begin{code}
-type NF_TcM s r = TcDown s -> TcEnv s -> SST s r
-type TcM s r = TcDown s -> TcEnv s -> FSST s r ()
+type NF_TcM r = TcDown -> TcEnv -> IO r -- Can't raise UserError
+type TcM r = TcDown -> TcEnv -> IO r -- Can raise UserError
+
+type Either_TcM r = TcDown -> TcEnv -> IO r -- Either NF_TcM or TcM
+ -- Used only in this file for type signatures which
+ -- have a part that's polymorphic in whether it's NF_TcM or TcM
+ -- E.g. thenNF_Tc
+
+type TcRef a = IORef a
\end{code}
\begin{code}
--- With a builtin polymorphic type for _runSST the type for
--- initTc should use TcM s r instead of TcM _RealWorld r
-
-initTc :: UniqSupply
- -> TcM _RealWorld r
- -> MaybeErr (r, Bag TcWarning)
- (Bag TcError, Bag TcWarning)
-
-initTc us do_this
- = _runSST (
- newMutVarSST us `thenSST` \ us_var ->
- newMutVarSST (emptyBag,emptyBag) `thenSST` \ errs_var ->
- newMutVarSST emptyUFM `thenSST` \ tvs_var ->
- let
- init_down = TcDown [] us_var
- mkUnknownSrcLoc
- [] errs_var
- init_env = initEnv tvs_var
- in
- recoverSST
- (\_ -> returnSST Nothing)
- (do_this init_down init_env `thenFSST` \ res ->
- returnFSST (Just res))
- `thenSST` \ maybe_res ->
- readMutVarSST errs_var `thenSST` \ (warns,errs) ->
- case (maybe_res, isEmptyBag errs) of
- (Just res, True) -> returnSST (Succeeded (res, warns))
- _ -> returnSST (Failed (errs, warns))
- )
-
-thenNF_Tc :: NF_TcM s a
- -> (a -> TcDown s -> TcEnv s -> State# s -> b)
- -> TcDown s -> TcEnv s -> State# s -> b
--- thenNF_Tc :: NF_TcM s a -> (a -> NF_TcM s b) -> NF_TcM s b
--- thenNF_Tc :: NF_TcM s a -> (a -> TcM s b) -> TcM s b
-
-thenNF_Tc m k down env
- = m down env `thenSST` \ r ->
- k r down env
-
-thenNF_Tc_ :: NF_TcM s a
- -> (TcDown s -> TcEnv s -> State# s -> b)
- -> TcDown s -> TcEnv s -> State# s -> b
--- thenNF_Tc :: NF_TcM s a -> NF_TcM s b -> NF_TcM s b
--- thenNF_Tc :: NF_TcM s a -> TcM s b -> TcM s b
-
-thenNF_Tc_ m k down env
- = m down env `thenSST_` k down env
-
-returnNF_Tc :: a -> NF_TcM s a
-returnNF_Tc v down env = returnSST v
-
-mapNF_Tc :: (a -> NF_TcM s b) -> [a] -> NF_TcM s [b]
-mapNF_Tc f [] = returnNF_Tc []
-mapNF_Tc f (x:xs) = f x `thenNF_Tc` \ r ->
- mapNF_Tc f xs `thenNF_Tc` \ rs ->
- returnNF_Tc (r:rs)
-
-listNF_Tc :: [NF_TcM s a] -> NF_TcM s [a]
-listNF_Tc [] = returnNF_Tc []
-listNF_Tc (x:xs) = x `thenNF_Tc` \ r ->
- listNF_Tc xs `thenNF_Tc` \ rs ->
- returnNF_Tc (r:rs)
-
-mapBagNF_Tc :: (a -> NF_TcM s b) -> Bag a -> NF_TcM s (Bag b)
-mapBagNF_Tc f bag
- = foldBag (\ b1 b2 -> b1 `thenNF_Tc` \ r1 ->
- b2 `thenNF_Tc` \ r2 ->
- returnNF_Tc (unionBags r1 r2))
- (\ a -> f a `thenNF_Tc` \ r -> returnNF_Tc (unitBag r))
- (returnNF_Tc emptyBag)
- bag
-mapAndUnzipNF_Tc :: (a -> NF_TcM s (b,c)) -> [a] -> NF_TcM s ([b],[c])
-mapAndUnzipNF_Tc f [] = returnNF_Tc ([],[])
-mapAndUnzipNF_Tc f (x:xs) = f x `thenNF_Tc` \ (r1,r2) ->
- mapAndUnzipNF_Tc f xs `thenNF_Tc` \ (rs1,rs2) ->
- returnNF_Tc (r1:rs1, r2:rs2)
+initTc :: DynFlags
+ -> TcEnv
+ -> TcM r
+ -> IO (Maybe r, (Bag WarnMsg, Bag ErrMsg))
-thenTc :: TcM s a -> (a -> TcM s b) -> TcM s b
-thenTc m k down env
- = m down env `thenFSST` \ r ->
- k r down env
+initTc dflags tc_env do_this
+ = do {
+ us <- mkSplitUniqSupply 'a' ;
+ us_var <- newIORef us ;
+ errs_var <- newIORef (emptyBag,emptyBag) ;
+ tvs_var <- newIORef emptyUFM ;
-thenTc_ :: TcM s a -> TcM s b -> TcM s b
-thenTc_ m k down env
- = m down env `thenFSST_` k down env
-
-returnTc :: a -> TcM s a
-returnTc val down env = returnFSST val
+ let
+ init_down = TcDown { tc_dflags = dflags, tc_def = [],
+ tc_us = us_var, tc_loc = noSrcLoc,
+ tc_ctxt = [], tc_errs = errs_var }
+ ;
+
+ maybe_res <- catch (do { res <- do_this init_down tc_env ;
+ return (Just res)})
+ (\_ -> return Nothing) ;
+
+ (warns,errs) <- readIORef errs_var ;
+ return (maybe_res, (warns, errs))
+ }
+
+-- Monadic operations
+
+returnNF_Tc :: a -> NF_TcM a
+returnTc :: a -> TcM a
+returnTc v down env = return v
+
+thenTc :: TcM a -> (a -> TcM b) -> TcM b
+thenNF_Tc :: NF_TcM a -> (a -> Either_TcM b) -> Either_TcM b
+thenTc m k down env = do { r <- m down env; k r down env }
+
+thenTc_ :: TcM a -> TcM b -> TcM b
+thenNF_Tc_ :: NF_TcM a -> Either_TcM b -> Either_TcM b
+thenTc_ m k down env = do { m down env; k down env }
+
+listTc :: [TcM a] -> TcM [a]
+listNF_Tc :: [NF_TcM a] -> NF_TcM [a]
+listTc [] = returnTc []
+listTc (x:xs) = x `thenTc` \ r ->
+ listTc xs `thenTc` \ rs ->
+ returnTc (r:rs)
-mapTc :: (a -> TcM s b) -> [a] -> TcM s [b]
+mapTc :: (a -> TcM b) -> [a] -> TcM [b]
+mapTc_ :: (a -> TcM b) -> [a] -> TcM ()
+mapNF_Tc :: (a -> NF_TcM b) -> [a] -> NF_TcM [b]
mapTc f [] = returnTc []
mapTc f (x:xs) = f x `thenTc` \ r ->
mapTc f xs `thenTc` \ rs ->
returnTc (r:rs)
+mapTc_ f xs = mapTc f xs `thenTc_` returnTc ()
-listTc :: [TcM s a] -> TcM s [a]
-listTc [] = returnTc []
-listTc (x:xs) = x `thenTc` \ r ->
- listTc xs `thenTc` \ rs ->
- returnTc (r:rs)
-foldrTc :: (a -> b -> TcM s b) -> b -> [a] -> TcM s b
+foldrTc :: (a -> b -> TcM b) -> b -> [a] -> TcM b
+foldrNF_Tc :: (a -> b -> NF_TcM b) -> b -> [a] -> NF_TcM b
foldrTc k z [] = returnTc z
foldrTc k z (x:xs) = foldrTc k z xs `thenTc` \r ->
k x r
-foldlTc :: (a -> b -> TcM s a) -> a -> [b] -> TcM s a
+foldlTc :: (a -> b -> TcM a) -> a -> [b] -> TcM a
+foldlNF_Tc :: (a -> b -> NF_TcM a) -> a -> [b] -> NF_TcM a
foldlTc k z [] = returnTc z
foldlTc k z (x:xs) = k z x `thenTc` \r ->
foldlTc k r xs
-mapAndUnzipTc :: (a -> TcM s (b,c)) -> [a] -> TcM s ([b],[c])
+mapAndUnzipTc :: (a -> TcM (b,c)) -> [a] -> TcM ([b],[c])
+mapAndUnzipNF_Tc :: (a -> NF_TcM (b,c)) -> [a] -> NF_TcM ([b],[c])
mapAndUnzipTc f [] = returnTc ([],[])
mapAndUnzipTc f (x:xs) = f x `thenTc` \ (r1,r2) ->
mapAndUnzipTc f xs `thenTc` \ (rs1,rs2) ->
returnTc (r1:rs1, r2:rs2)
-mapAndUnzip3Tc :: (a -> TcM s (b,c,d)) -> [a] -> TcM s ([b],[c],[d])
+mapAndUnzip3Tc :: (a -> TcM (b,c,d)) -> [a] -> TcM ([b],[c],[d])
mapAndUnzip3Tc f [] = returnTc ([],[],[])
mapAndUnzip3Tc f (x:xs) = f x `thenTc` \ (r1,r2,r3) ->
mapAndUnzip3Tc f xs `thenTc` \ (rs1,rs2,rs3) ->
returnTc (r1:rs1, r2:rs2, r3:rs3)
-mapBagTc :: (a -> TcM s b) -> Bag a -> TcM s (Bag b)
+mapBagTc :: (a -> TcM b) -> Bag a -> TcM (Bag b)
+mapBagNF_Tc :: (a -> NF_TcM b) -> Bag a -> NF_TcM (Bag b)
mapBagTc f bag
= foldBag (\ b1 b2 -> b1 `thenTc` \ r1 ->
b2 `thenTc` \ r2 ->
(returnTc emptyBag)
bag
-fixTc :: (a -> TcM s a) -> TcM s a
-fixTc m env down = fixFSST (\ loop -> m loop env down)
+fixTc :: (a -> TcM a) -> TcM a
+fixNF_Tc :: (a -> NF_TcM a) -> NF_TcM a
+fixTc m env down = fixIO (\ loop -> m loop env down)
+{-# NOINLINE fixTc #-}
+-- aargh! Not inlining fixTc alleviates a space leak problem.
+-- Normally fixTc is used with a lazy tuple match: if the optimiser is
+-- shown the definition of fixTc, it occasionally transforms the code
+-- in such a way that the code generator doesn't spot the selector
+-- thunks. Sigh.
+
+recoverTc :: TcM r -> TcM r -> TcM r
+recoverNF_Tc :: NF_TcM r -> TcM r -> NF_TcM r
+recoverTc recover m down env
+ = catch (m down env) (\ _ -> recover down env)
+
+returnNF_Tc = returnTc
+thenNF_Tc = thenTc
+thenNF_Tc_ = thenTc_
+fixNF_Tc = fixTc
+recoverNF_Tc = recoverTc
+mapNF_Tc = mapTc
+foldrNF_Tc = foldrTc
+foldlNF_Tc = foldlTc
+listNF_Tc = listTc
+mapAndUnzipNF_Tc = mapAndUnzipTc
+mapBagNF_Tc = mapBagTc
+\end{code}
+
+@forkNF_Tc@ runs a sub-typecheck action *lazily* in a separate state
+thread. Ideally, this elegantly ensures that it can't zap any type
+variables that belong to the main thread. But alas, the environment
+contains TyCon and Class environments that include TcKind stuff,
+which is a Royal Pain. By the time this fork stuff is used they'll
+have been unified down so there won't be any kind variables, but we
+can't express that in the current typechecker framework.
+
+So we compromise and use unsafeInterleaveIO.
+
+We throw away any error messages!
+
+\begin{code}
+forkNF_Tc :: NF_TcM r -> NF_TcM r
+forkNF_Tc m down@(TcDown { tc_us = u_var }) env
+ = do
+ -- Get a fresh unique supply
+ us <- readIORef u_var
+ let (us1, us2) = splitUniqSupply us
+ writeIORef u_var us1
+
+ unsafeInterleaveIO (do {
+ us_var' <- newIORef us2 ;
+ err_var' <- newIORef (emptyBag,emptyBag) ;
+ let { down' = down { tc_us = us_var', tc_errs = err_var' } };
+ m down' env
+ -- ToDo: optionally dump any error messages
+ })
\end{code}
-@forkNF_Tc@ runs a sub-typecheck action in a separate state thread.
-This elegantly ensures that it can't zap any type variables that
-belong to the main thread. We throw away any error messages!
+\begin{code}
+traceTc :: SDoc -> NF_TcM ()
+traceTc doc (TcDown { tc_dflags=dflags }) env
+ | dopt Opt_D_dump_tc_trace dflags = printDump doc
+ | otherwise = return ()
+
+ioToTc :: IO a -> NF_TcM a
+ioToTc io down env = io
+\end{code}
-\begin{pseudocode}
-forkNF_Tc :: NF_TcM s r -> NF_TcM s r
-forkNF_Tc m down env
- = forkTcDown down `thenSST` \ down' ->
- returnSST (_runSST (m down' (forkTcEnv env)))
-\end{pseudocode}
+%************************************************************************
+%* *
+\subsection{Error handling}
+%* *
+%************************************************************************
-Error handling
-~~~~~~~~~~~~~~
\begin{code}
-failTc :: Message -> TcM s a
-failTc err_msg down env
- = readMutVarSST errs_var `thenSST` \ (warns,errs) ->
- foldr thenNF_Tc_ (returnNF_Tc []) ctxt down env `thenSST` \ ctxt_msgs ->
- let
- err = mkTcErr loc ctxt_msgs err_msg
- in
- writeMutVarSST errs_var (warns, errs `snocBag` err) `thenSST_`
- failFSST ()
+getErrsTc :: NF_TcM (Bag WarnMsg, Bag ErrMsg)
+getErrsTc down env
+ = readIORef (getTcErrs down)
+
+failTc :: TcM a
+failTc down env = give_up
+
+give_up :: IO a
+give_up = ioError (userError "Typecheck failed")
+
+failWithTc :: Message -> TcM a -- Add an error message and fail
+failWithTc err_msg = failWithTcM (emptyTidyEnv, err_msg)
+
+addErrTc :: Message -> NF_TcM ()
+addErrTc err_msg = addErrTcM (emptyTidyEnv, err_msg)
+
+addErrsTc :: [Message] -> NF_TcM ()
+addErrsTc [] = returnNF_Tc ()
+addErrsTc err_msgs = listNF_Tc (map addErrTc err_msgs) `thenNF_Tc_` returnNF_Tc ()
+
+-- The 'M' variants do the TidyEnv bit
+failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
+failWithTcM env_and_msg
+ = addErrTcM env_and_msg `thenNF_Tc_`
+ failTc
+
+checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
+checkTc True err = returnTc ()
+checkTc False err = failWithTc err
+
+checkTcM :: Bool -> TcM () -> TcM () -- Check that the boolean is true
+checkTcM True err = returnTc ()
+checkTcM False err = err
+
+checkMaybeTc :: Maybe val -> Message -> TcM val
+checkMaybeTc (Just val) err = returnTc val
+checkMaybeTc Nothing err = failWithTc err
+
+checkMaybeTcM :: Maybe val -> TcM val -> TcM val
+checkMaybeTcM (Just val) err = returnTc val
+checkMaybeTcM Nothing err = err
+
+addErrTcM :: (TidyEnv, Message) -> NF_TcM () -- Add an error message but don't fail
+addErrTcM (tidy_env, err_msg) down env
+ = add_err_tcm tidy_env err_msg ctxt loc down env
+ where
+ ctxt = getErrCtxt down
+ loc = getLoc down
+
+addInstErrTcM :: InstLoc -> (TidyEnv, Message) -> NF_TcM () -- Add an error message but don't fail
+addInstErrTcM inst_loc@(_, loc, ctxt) (tidy_env, err_msg) down env
+ = add_err_tcm tidy_env err_msg full_ctxt loc down env
+ where
+ full_ctxt = (\env -> returnNF_Tc (env, pprInstLoc inst_loc)) : ctxt
+
+add_err_tcm tidy_env err_msg ctxt loc down env
+ = do
+ (warns, errs) <- readIORef errs_var
+ ctxt_msgs <- do_ctxt tidy_env ctxt down env
+ let err = addShortErrLocLine loc $
+ vcat (err_msg : ctxt_to_use ctxt_msgs)
+ writeIORef errs_var (warns, errs `snocBag` err)
+ where
+ errs_var = getTcErrs down
+
+do_ctxt tidy_env [] down env
+ = return []
+do_ctxt tidy_env (c:cs) down env
+ = do
+ (tidy_env', m) <- c tidy_env down env
+ ms <- do_ctxt tidy_env' cs down env
+ return (m:ms)
+
+-- warnings don't have an 'M' variant
+warnTc :: Bool -> Message -> NF_TcM ()
+warnTc warn_if_true warn_msg down env
+ | warn_if_true
+ = do
+ (warns,errs) <- readIORef errs_var
+ ctxt_msgs <- do_ctxt emptyTidyEnv ctxt down env
+ let warn = addShortWarnLocLine loc $
+ vcat (warn_msg : ctxt_to_use ctxt_msgs)
+ writeIORef errs_var (warns `snocBag` warn, errs)
+ | otherwise
+ = return ()
where
errs_var = getTcErrs down
ctxt = getErrCtxt down
loc = getLoc down
-warnTc :: Bool -> Message -> NF_TcM s ()
-warnTc warn_if_true warn down env
- = if warn_if_true then
- readMutVarSST errs_var `thenSST` \ (warns,errs) ->
- writeMutVarSST errs_var (warns `snocBag` warn, errs) `thenSST_`
- returnSST ()
- else
- returnSST ()
+-- (tryTc r m) succeeds if m succeeds and generates no errors
+-- If m fails then r is invoked, passing the warnings and errors from m
+-- If m succeeds, (tryTc r m) checks whether m generated any errors messages
+-- (it might have recovered internally)
+-- If so, then r is invoked, passing the warnings and errors from m
+
+tryTc :: ((Bag WarnMsg, Bag ErrMsg) -> TcM r) -- Recovery action
+ -> TcM r -- Thing to try
+ -> TcM r
+tryTc recover main down env
+ = do
+ m_errs_var <- newIORef (emptyBag,emptyBag)
+ catch (my_main m_errs_var) (\ _ -> my_recover m_errs_var)
where
errs_var = getTcErrs down
-recoverTc :: TcM s r -> TcM s r -> TcM s r
-recoverTc recover m down env
- = recoverFSST (\ _ -> recover down env) (m down env)
+ my_recover m_errs_var
+ = do warns_and_errs <- readIORef m_errs_var
+ recover warns_and_errs down env
+
+ my_main m_errs_var
+ = do result <- main (setTcErrs down m_errs_var) env
+
+ -- Check that m has no errors; if it has internal recovery
+ -- mechanisms it might "succeed" but having found a bunch of
+ -- errors along the way.
+ (m_warns, m_errs) <- readIORef m_errs_var
+ if isEmptyBag m_errs then
+ -- No errors, so return normally, but don't lose the warnings
+ if isEmptyBag m_warns then
+ return result
+ else
+ do (warns, errs) <- readIORef errs_var
+ writeIORef errs_var (warns `unionBags` m_warns, errs)
+ return result
+ else
+ give_up -- This triggers the catch
+
+
+-- (checkNoErrsTc m) succeeds iff m succeeds and generates no errors
+-- If m fails then (checkNoErrsTc m) fails.
+-- If m succeeds, it checks whether m generated any errors messages
+-- (it might have recovered internally)
+-- If so, it fails too.
+-- Regardless, any errors generated by m are propagated to the enclosing context.
+checkNoErrsTc :: TcM r -> TcM r
+checkNoErrsTc main
+ = tryTc my_recover main
+ where
+ my_recover (m_warns, m_errs) down env
+ = do (warns, errs) <- readIORef errs_var
+ writeIORef errs_var (warns `unionBags` m_warns,
+ errs `unionBags` m_errs)
+ give_up
+ where
+ errs_var = getTcErrs down
-recoverNF_Tc :: NF_TcM s r -> TcM s r -> NF_TcM s r
-recoverNF_Tc recover m down env
- = recoverSST (\ _ -> recover down env) (m down env)
--- (tryTc r m) tries m; if it succeeds it returns it,
+-- (tryTc_ r m) tries m; if it succeeds it returns it,
-- otherwise it returns r. Any error messages added by m are discarded,
-- whether or not m succeeds.
-tryTc :: TcM s r -> TcM s r -> TcM s r
-tryTc recover m down env
- = recoverFSST (\ _ -> recover down env) $
- newMutVarSST (emptyBag,emptyBag) `thenSST` \ new_errs_var ->
- m (setTcErrs down new_errs_var) env
+tryTc_ :: TcM r -> TcM r -> TcM r
+tryTc_ recover main
+ = tryTc my_recover main
+ where
+ my_recover warns_and_errs = recover
-checkTc :: Bool -> Message -> TcM s () -- Check that the boolean is true
-checkTc True err = returnTc ()
-checkTc False err = failTc err
+-- (discardErrsTc m) runs m, but throw away all its error messages.
+discardErrsTc :: Either_TcM r -> Either_TcM r
+discardErrsTc main down env
+ = do new_errs_var <- newIORef (emptyBag,emptyBag)
+ main (setTcErrs down new_errs_var) env
+\end{code}
-checkTcM :: Bool -> TcM s () -> TcM s () -- Check that the boolean is true
-checkTcM True err = returnTc ()
-checkTcM False err = err
-checkMaybeTc :: Maybe val -> Message -> TcM s val
-checkMaybeTc (Just val) err = returnTc val
-checkMaybeTc Nothing err = failTc err
-checkMaybeTcM :: Maybe val -> TcM s val -> TcM s val
-checkMaybeTcM (Just val) err = returnTc val
-checkMaybeTcM Nothing err = err
-\end{code}
+%************************************************************************
+%* *
+\subsection{Mutable variables}
+%* *
+%************************************************************************
-Mutable variables
-~~~~~~~~~~~~~~~~~
\begin{code}
-tcNewMutVar :: a -> NF_TcM s (MutableVar s a)
-tcNewMutVar val down env = newMutVarSST val
+tcNewMutVar :: a -> NF_TcM (TcRef a)
+tcNewMutVar val down env = newIORef val
+
+tcWriteMutVar :: TcRef a -> a -> NF_TcM ()
+tcWriteMutVar var val down env = writeIORef var val
+
+tcReadMutVar :: TcRef a -> NF_TcM a
+tcReadMutVar var down env = readIORef var
-tcWriteMutVar :: MutableVar s a -> a -> NF_TcM s ()
-tcWriteMutVar var val down env = writeMutVarSST var val
+tcNewMutTyVar :: Name -> Kind -> TyVarDetails -> NF_TcM TyVar
+tcNewMutTyVar name kind details down env = newMutTyVar name kind details
-tcReadMutVar :: MutableVar s a -> NF_TcM s a
-tcReadMutVar var down env = readMutVarSST var
+tcReadMutTyVar :: TyVar -> NF_TcM (Maybe Type)
+tcReadMutTyVar tyvar down env = readMutTyVar tyvar
+
+tcWriteMutTyVar :: TyVar -> Maybe Type -> NF_TcM ()
+tcWriteMutTyVar tyvar val down env = writeMutTyVar tyvar val
\end{code}
-Environment
-~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{The environment}
+%* *
+%************************************************************************
+
\begin{code}
-tcGetEnv :: NF_TcM s (TcEnv s)
-tcGetEnv down env = returnSST env
+tcGetEnv :: NF_TcM TcEnv
+tcGetEnv down env = return env
-tcSetEnv :: TcEnv s -> TcM s a -> TcM s a
+tcSetEnv :: TcEnv -> Either_TcM a -> Either_TcM a
tcSetEnv new_env m down old_env = m down new_env
\end{code}
-Source location
-~~~~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{Source location}
+%* *
+%************************************************************************
+
\begin{code}
-tcGetDefaultTys :: NF_TcM s [Type]
-tcGetDefaultTys down env = returnSST (getDefaultTys down)
+tcGetDefaultTys :: NF_TcM [Type]
+tcGetDefaultTys down env = return (getDefaultTys down)
-tcSetDefaultTys :: [Type] -> TcM s r -> TcM s r
+tcSetDefaultTys :: [Type] -> TcM r -> TcM r
tcSetDefaultTys tys m down env = m (setDefaultTys down tys) env
-tcAddSrcLoc :: SrcLoc -> TcM s a -> TcM s a
+tcAddSrcLoc :: SrcLoc -> Either_TcM a -> Either_TcM a
tcAddSrcLoc loc m down env = m (setLoc down loc) env
-tcGetSrcLoc :: NF_TcM s SrcLoc
-tcGetSrcLoc down env = returnSST (getLoc down)
+tcGetSrcLoc :: NF_TcM SrcLoc
+tcGetSrcLoc down env = return (getLoc down)
-tcSetErrCtxtM, tcAddErrCtxtM :: NF_TcM s Message -> TcM s a -> TcM s a
+tcGetInstLoc :: InstOrigin -> NF_TcM InstLoc
+tcGetInstLoc origin TcDown{tc_loc=loc, tc_ctxt=ctxt} env
+ = return (origin, loc, ctxt)
+
+tcSetErrCtxtM, tcAddErrCtxtM :: (TidyEnv -> NF_TcM (TidyEnv, Message))
+ -> TcM a -> TcM a
tcSetErrCtxtM msg m down env = m (setErrCtxt down msg) env
tcAddErrCtxtM msg m down env = m (addErrCtxt down msg) env
-tcSetErrCtxt, tcAddErrCtxt :: Message -> TcM s a -> TcM s a
-tcSetErrCtxt msg m down env = m (setErrCtxt down (returnNF_Tc msg)) env
-tcAddErrCtxt msg m down env = m (addErrCtxt down (returnNF_Tc msg)) env
+tcSetErrCtxt, tcAddErrCtxt :: Message -> Either_TcM r -> Either_TcM r
+-- Usual thing
+tcSetErrCtxt msg m down env = m (setErrCtxt down (\env -> returnNF_Tc (env, msg))) env
+tcAddErrCtxt msg m down env = m (addErrCtxt down (\env -> returnNF_Tc (env, msg))) env
+
+tcPopErrCtxt :: Either_TcM r -> Either_TcM r
+tcPopErrCtxt m down env = m (popErrCtxt down) env
\end{code}
-Unique supply
-~~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{Unique supply}
+%* *
+%************************************************************************
+
\begin{code}
-tcGetUnique :: NF_TcM s Unique
+tcGetUnique :: NF_TcM Unique
tcGetUnique down env
- = readMutVarSST u_var `thenSST` \ uniq_supply ->
- let
- (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
- uniq = getUnique uniq_s
- in
- writeMutVarSST u_var new_uniq_supply `thenSST_`
- returnSST uniq
+ = do uniq_supply <- readIORef u_var
+ let (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
+ uniq = uniqFromSupply uniq_s
+ writeIORef u_var new_uniq_supply
+ return uniq
where
u_var = getUniqSupplyVar down
-tcGetUniques :: Int -> NF_TcM s [Unique]
-tcGetUniques n down env
- = readMutVarSST u_var `thenSST` \ uniq_supply ->
- let
- (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
- uniqs = getUniques n uniq_s
- in
- writeMutVarSST u_var new_uniq_supply `thenSST_`
- returnSST uniqs
+tcGetUniques :: NF_TcM [Unique]
+tcGetUniques down env
+ = do uniq_supply <- readIORef u_var
+ let (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
+ uniqs = uniqsFromSupply uniq_s
+ writeIORef u_var new_uniq_supply
+ return uniqs
where
u_var = getUniqSupplyVar down
-\end{code}
+uniqSMToTcM :: UniqSM a -> NF_TcM a
+uniqSMToTcM m down env
+ = do uniq_supply <- readIORef u_var
+ let (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
+ writeIORef u_var new_uniq_supply
+ return (initUs_ uniq_s m)
+ where
+ u_var = getUniqSupplyVar down
+\end{code}
-\section{TcDown}
-%~~~~~~~~~~~~~~~
-
-\begin{code}
-data TcDown s
- = TcDown
- [Type] -- Types used for defaulting
- (MutableVar s UniqSupply) -- Unique supply
- SrcLoc -- Source location
- (ErrCtxt s) -- Error context
- (MutableVar s (Bag TcWarning,
- Bag TcError))
+%************************************************************************
+%* *
+\subsection{TcDown}
+%* *
+%************************************************************************
-type ErrCtxt s = [NF_TcM s Message] -- Innermost first. Monadic so that we have a chance
- -- to deal with bound type variables just before error
- -- message construction
+\begin{code}
+data TcDown
+ = TcDown {
+ tc_dflags :: DynFlags,
+ tc_def :: [Type], -- Types used for defaulting
+ tc_us :: (TcRef UniqSupply), -- Unique supply
+ tc_loc :: SrcLoc, -- Source location
+ tc_ctxt :: ErrCtxt, -- Error context
+ tc_errs :: (TcRef (Bag WarnMsg, Bag ErrMsg))
+ }
+
+type ErrCtxt = [TidyEnv -> NF_TcM (TidyEnv, Message)]
+ -- Innermost first. Monadic so that we have a chance
+ -- to deal with bound type variables just before error
+ -- message construction
\end{code}
-- These selectors are *local* to TcMonad.lhs
\begin{code}
-getTcErrs (TcDown def us loc ctxt errs) = errs
-setTcErrs (TcDown def us loc ctxt _ ) errs = TcDown def us loc ctxt errs
+getTcErrs (TcDown{tc_errs=errs}) = errs
+setTcErrs down errs = down{tc_errs=errs}
+
+getDefaultTys (TcDown{tc_def=def}) = def
+setDefaultTys down def = down{tc_def=def}
-getDefaultTys (TcDown def us loc ctxt errs) = def
-setDefaultTys (TcDown _ us loc ctxt errs) def = TcDown def us loc ctxt errs
+getLoc (TcDown{tc_loc=loc}) = loc
+setLoc down loc = down{tc_loc=loc}
-getLoc (TcDown def us loc ctxt errs) = loc
-setLoc (TcDown def us _ ctxt errs) loc = TcDown def us loc ctxt errs
+getUniqSupplyVar (TcDown{tc_us=us}) = us
-getUniqSupplyVar (TcDown def us loc ctxt errs) = us
+getErrCtxt (TcDown{tc_ctxt=ctxt}) = ctxt
+setErrCtxt down msg = down{tc_ctxt=[msg]}
+addErrCtxt down msg = down{tc_ctxt = msg : tc_ctxt down}
-setErrCtxt (TcDown def us loc ctxt errs) msg = TcDown def us loc [msg] errs
-addErrCtxt (TcDown def us loc ctxt errs) msg = TcDown def us loc (msg:ctxt) errs
-getErrCtxt (TcDown def us loc ctxt errs) = ctxt
+popErrCtxt down = case tc_ctxt down of
+ [] -> down
+ m : ms -> down{tc_ctxt = ms}
+
+doptsTc :: DynFlag -> NF_TcM Bool
+doptsTc dflag (TcDown{tc_dflags=dflags}) env_down
+ = return (dopt dflag dflags)
+
+getDOptsTc :: NF_TcM DynFlags
+getDOptsTc (TcDown{tc_dflags=dflags}) env_down
+ = return dflags
\end{code}
-@forkTcDown@ makes a new "down" blob for a lazily-computed fork
-of the type checker.
+
+
+
+%************************************************************************
+%* *
+\subsection{TypeChecking Errors}
+%* *
+%************************************************************************
\begin{code}
-forkTcDown (TcDown deflts u_var src_loc err_cxt err_var)
- = -- Get a fresh unique supply
- readMutVarSST u_var `thenSST` \ us ->
- let
- (us1, us2) = splitUniqSupply us
- in
- writeMutVarSST u_var us1 `thenSST_`
-
- -- Make fresh MutVars for the unique supply and errors
- newMutVarSST us2 `thenSST` \ u_var' ->
- newMutVarSST (emptyBag, emptyBag) `thenSST` \ err_var' ->
-
- -- Done
- returnSST (TcDown deflts u_var' src_loc err_cxt err_var')
+type TcError = Message
+type TcWarning = Message
+
+ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
+ | otherwise = take 3 ctxt
+
+arityErr kind name n m
+ = hsep [ text kind, quotes (ppr name), ptext SLIT("should have"),
+ n_arguments <> comma, text "but has been given", int m]
+ where
+ n_arguments | n == 0 = ptext SLIT("no arguments")
+ | n == 1 = ptext SLIT("1 argument")
+ | True = hsep [int n, ptext SLIT("arguments")]
\end{code}
-\section{rn4MtoTcM}
-%~~~~~~~~~~~~~~~~~~
+
+%************************************************************************
+%* *
+\subsection[Inst-origin]{The @InstOrigin@ type}
+%* *
+%************************************************************************
+
+The @InstOrigin@ type gives information about where a dictionary came from.
+This is important for decent error message reporting because dictionaries
+don't appear in the original source code. Doubtless this type will evolve...
+
+It appears in TcMonad because there are a couple of error-message-generation
+functions that deal with it.
\begin{code}
-rn4MtoTcM :: GlobalNameMappers -> Rn4M a -> NF_TcM s (a, Bag Error)
-
-rn4MtoTcM name_funs rn_action down env
- = readMutVarSST u_var `thenSST` \ uniq_supply ->
- let
- (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
- in
- writeMutVarSST u_var new_uniq_supply `thenSST_`
- let
- (rn_result, rn_errs)
- = rn_action name_funs emptyFM emptyBag uniq_s mkUnknownSrcLoc
- in
- returnSST (rn_result, rn_errs)
+type InstLoc = (InstOrigin, SrcLoc, ErrCtxt)
+
+data InstOrigin
+ = OccurrenceOf Id -- Occurrence of an overloaded identifier
+
+ | IPOcc (IPName Name) -- Occurrence of an implicit parameter
+ | IPBind (IPName Name) -- Binding site of an implicit parameter
+
+ | RecordUpdOrigin
+
+ | DataDeclOrigin -- Typechecking a data declaration
+
+ | InstanceDeclOrigin -- Typechecking an instance decl
+
+ | LiteralOrigin HsOverLit -- Occurrence of a literal
+
+ | PatOrigin RenamedPat
+
+ | ArithSeqOrigin RenamedArithSeqInfo -- [x..], [x..y] etc
+ | PArrSeqOrigin RenamedArithSeqInfo -- [:x..y:] and [:x,y..z:]
+
+ | SignatureOrigin -- A dict created from a type signature
+ | Rank2Origin -- A dict created when typechecking the argument
+ -- of a rank-2 typed function
+
+ | DoOrigin -- The monad for a do expression
+
+ | ClassDeclOrigin -- Manufactured during a class decl
+
+ | InstanceSpecOrigin Class -- in a SPECIALIZE instance pragma
+ Type
+
+ -- When specialising instances the instance info attached to
+ -- each class is not yet ready, so we record it inside the
+ -- origin information. This is a bit of a hack, but it works
+ -- fine. (Patrick is to blame [WDP].)
+
+ | ValSpecOrigin Name -- in a SPECIALIZE pragma for a value
+
+ -- Argument or result of a ccall
+ -- Dictionaries with this origin aren't actually mentioned in the
+ -- translated term, and so need not be bound. Nor should they
+ -- be abstracted over.
+
+ | CCallOrigin String -- CCall label
+ (Maybe RenamedHsExpr) -- Nothing if it's the result
+ -- Just arg, for an argument
+
+ | LitLitOrigin String -- the litlit
+
+ | UnknownOrigin -- Help! I give up...
+\end{code}
+
+\begin{code}
+pprInstLoc :: InstLoc -> SDoc
+pprInstLoc (orig, locn, ctxt)
+ = hsep [text "arising from", pp_orig orig, text "at", ppr locn]
where
- u_var = getUniqSupplyVar down
+ pp_orig (OccurrenceOf id)
+ = hsep [ptext SLIT("use of"), quotes (ppr id)]
+ pp_orig (IPOcc name)
+ = hsep [ptext SLIT("use of implicit parameter"), quotes (char '?' <> ppr name)]
+ pp_orig (IPBind name)
+ = hsep [ptext SLIT("binding for implicit parameter"), quotes (char '?' <> ppr name)]
+ pp_orig RecordUpdOrigin
+ = ptext SLIT("a record update")
+ pp_orig DataDeclOrigin
+ = ptext SLIT("the data type declaration")
+ pp_orig InstanceDeclOrigin
+ = ptext SLIT("the instance declaration")
+ pp_orig (LiteralOrigin lit)
+ = hsep [ptext SLIT("the literal"), quotes (ppr lit)]
+ pp_orig (PatOrigin pat)
+ = hsep [ptext SLIT("the pattern"), quotes (ppr pat)]
+ pp_orig (ArithSeqOrigin seq)
+ = hsep [ptext SLIT("the arithmetic sequence"), quotes (ppr seq)]
+ pp_orig (PArrSeqOrigin seq)
+ = hsep [ptext SLIT("the parallel array sequence"), quotes (ppr seq)]
+ pp_orig (SignatureOrigin)
+ = ptext SLIT("a type signature")
+ pp_orig (Rank2Origin)
+ = ptext SLIT("a function with an overloaded argument type")
+ pp_orig (DoOrigin)
+ = ptext SLIT("a do statement")
+ pp_orig (ClassDeclOrigin)
+ = ptext SLIT("a class declaration")
+ pp_orig (InstanceSpecOrigin clas ty)
+ = hsep [text "a SPECIALIZE instance pragma; class",
+ quotes (ppr clas), text "type:", ppr ty]
+ pp_orig (ValSpecOrigin name)
+ = hsep [ptext SLIT("a SPECIALIZE user-pragma for"), quotes (ppr name)]
+ pp_orig (CCallOrigin clabel Nothing{-ccall result-})
+ = hsep [ptext SLIT("the result of the _ccall_ to"), quotes (text clabel)]
+ pp_orig (CCallOrigin clabel (Just arg_expr))
+ = hsep [ptext SLIT("an argument in the _ccall_ to"), quotes (text clabel) <> comma,
+ text "namely", quotes (ppr arg_expr)]
+ pp_orig (LitLitOrigin s)
+ = hsep [ptext SLIT("the ``literal-literal''"), quotes (text s)]
+ pp_orig (UnknownOrigin)
+ = ptext SLIT("...oops -- I don't know where the overloading came from!")
\end{code}
projects / ghc-hetmet.git / blobdiff