\begin{code}
module TcMonad(
- TcType,
- TcTauType, TcThetaType, TcRhoType,
- TcTyVar, TcTyVarSet,
- TcKind,
-
TcM, NF_TcM, TcDown, TcEnv,
initTc,
- returnTc, thenTc, thenTc_, mapTc, listTc,
+ returnTc, thenTc, thenTc_, mapTc, mapTc_, listTc,
foldrTc, foldlTc, mapAndUnzipTc, mapAndUnzip3Tc,
mapBagTc, fixTc, tryTc, tryTc_, getErrsTc,
traceTc, ioToTc,
listNF_Tc, mapAndUnzipNF_Tc, mapBagNF_Tc,
checkTc, checkTcM, checkMaybeTc, checkMaybeTcM,
- failTc, failWithTc, addErrTc, warnTc, recoverTc, checkNoErrsTc, recoverNF_Tc, discardErrsTc,
- addErrTcM, failWithTcM,
+ 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, tcNewSigTyVar, tcReadMutVar, tcWriteMutVar, TcRef,
+ tcNewMutVar, tcReadMutVar, tcWriteMutVar, TcRef,
tcNewMutTyVar, tcReadMutTyVar, tcWriteMutTyVar,
+ InstOrigin(..), InstLoc, pprInstLoc,
+
TcError, TcWarning, TidyEnv, emptyTidyEnv,
arityErr
) where
import {-# SOURCE #-} TcEnv ( TcEnv )
-import Type ( Type, Kind, ThetaType, RhoType, TauType,
- )
+import HsLit ( HsOverLit )
+import RnHsSyn ( RenamedPat, RenamedArithSeqInfo, RenamedHsExpr )
+import TcType ( Type, Kind, TyVarDetails )
import ErrUtils ( addShortErrLocLine, addShortWarnLocLine, ErrMsg, Message, WarnMsg )
-import CmdLineOpts ( opt_PprStyle_Debug )
import Bag ( Bag, emptyBag, isEmptyBag,
foldBag, unitBag, unionBags, snocBag )
import Class ( Class )
import Name ( Name )
-import Var ( TyVar, newMutTyVar, newSigTyVar, readMutTyVar, writeMutTyVar )
-import VarEnv ( TyVarEnv, emptyVarEnv, TidyEnv, emptyTidyEnv )
-import VarSet ( TyVarSet )
-import UniqSupply ( UniqSupply, uniqFromSupply, uniqsFromSupply, 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 FiniteMap ( FiniteMap, emptyFM )
-import UniqFM ( UniqFM, emptyUFM )
+import BasicTypes ( IPName )
+import UniqFM ( emptyUFM )
import Unique ( Unique )
-import BasicTypes ( Unused )
-import Util
+import CmdLineOpts
import Outputable
-import FastString ( FastString )
import IOExts ( IORef, newIORef, readIORef, writeIORef,
unsafeInterleaveIO, fixIO
\end{code}
-Types
-~~~~~
-\begin{code}
-type TcTyVar = TyVar -- Might be a mutable tyvar
-type TcTyVarSet = TyVarSet
-
-type TcType = Type -- A TcType can have mutable type variables
- -- Invariant on ForAllTy in TcTypes:
- -- forall a. T
- -- a cannot occur inside a MutTyVar in T; that is,
- -- T is "flattened" before quantifying over a
-
-type TcThetaType = ThetaType
-type TcRhoType = RhoType
-type TcTauType = TauType
-type TcKind = TcType
-\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 -> TcEnv -> IO r -- Can't raise UserError
-type TcM s r = TcDown -> TcEnv -> IO r -- Can raise UserError
- -- ToDo: nuke the 's' part
- -- The difference between the two is
- -- now for documentation purposes only
+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 s r = TcDown -> TcEnv -> IO r -- Either NF_TcM or TcM
+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
\end{code}
\begin{code}
--- initEnv is passed in to avoid module recursion between TcEnv & TcMonad.
-initTc :: UniqSupply
- -> (TcRef (UniqFM a) -> TcEnv)
- -> TcM s r
- -> IO (Maybe r, Bag WarnMsg, Bag ErrMsg)
+initTc :: DynFlags
+ -> TcEnv
+ -> TcM r
+ -> IO (Maybe r, (Bag WarnMsg, Bag ErrMsg))
-initTc us initenv do_this
+initTc dflags tc_env do_this
= do {
+ us <- mkSplitUniqSupply 'a' ;
us_var <- newIORef us ;
errs_var <- newIORef (emptyBag,emptyBag) ;
tvs_var <- newIORef emptyUFM ;
let
- init_down = TcDown [] us_var
- noSrcLoc
- [] errs_var
- init_env = initenv tvs_var
+ 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 init_env ;
+ 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)
+ return (maybe_res, (warns, errs))
}
-- Monadic operations
-returnNF_Tc :: a -> NF_TcM s a
-returnTc :: a -> TcM s a
+returnNF_Tc :: a -> NF_TcM a
+returnTc :: a -> TcM a
returnTc v down env = return v
-thenTc :: TcM s a -> (a -> TcM s b) -> TcM s b
-thenNF_Tc :: NF_TcM s a -> (a -> Either_TcM s b) -> Either_TcM s b
+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 s a -> TcM s b -> TcM s b
-thenNF_Tc_ :: NF_TcM s a -> Either_TcM s b -> Either_TcM s b
+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 s a] -> TcM s [a]
-listNF_Tc :: [NF_TcM s a] -> NF_TcM s [a]
+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]
-mapNF_Tc :: (a -> NF_TcM s b) -> [a] -> NF_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 ()
+
-foldrTc :: (a -> b -> TcM s b) -> b -> [a] -> TcM s b
-foldrNF_Tc :: (a -> b -> NF_TcM s b) -> b -> [a] -> NF_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
-foldlNF_Tc :: (a -> b -> NF_TcM s a) -> a -> [b] -> NF_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])
-mapAndUnzipNF_Tc :: (a -> NF_TcM s (b,c)) -> [a] -> NF_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)
-mapBagNF_Tc :: (a -> NF_TcM s b) -> Bag a -> NF_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
-fixNF_Tc :: (a -> NF_TcM s a) -> NF_TcM s a
+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)
-
-recoverTc :: TcM s r -> TcM s r -> TcM s r
-recoverNF_Tc :: NF_TcM s r -> TcM s r -> NF_TcM s r
+{-# 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)
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 unsafeInterleaveSST.
+So we compromise and use unsafeInterleaveIO.
We throw away any error messages!
\begin{code}
-forkNF_Tc :: NF_TcM s r -> NF_TcM s r
-forkNF_Tc m (TcDown deflts u_var src_loc err_cxt err_var) env
+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
unsafeInterleaveIO (do {
us_var' <- newIORef us2 ;
err_var' <- newIORef (emptyBag,emptyBag) ;
- tv_var' <- newIORef emptyUFM ;
- let { down' = TcDown deflts us_var' src_loc err_cxt err_var' } ;
+ let { down' = down { tc_us = us_var', tc_errs = err_var' } };
m down' env
-- ToDo: optionally dump any error messages
})
\end{code}
\begin{code}
-traceTc :: SDoc -> NF_TcM s ()
-traceTc doc down env = printErrs doc
+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 s a
+ioToTc :: IO a -> NF_TcM a
ioToTc io down env = io
\end{code}
%************************************************************************
\begin{code}
-getErrsTc :: NF_TcM s (Bag WarnMsg, Bag ErrMsg)
+getErrsTc :: NF_TcM (Bag WarnMsg, Bag ErrMsg)
getErrsTc down env
= readIORef (getTcErrs down)
-failTc :: TcM s a
+failTc :: TcM a
failTc down env = give_up
give_up :: IO a
-give_up = IOERROR (userError "Typecheck failed")
+give_up = ioError (userError "Typecheck failed")
-failWithTc :: Message -> TcM s a -- Add an error message and fail
+failWithTc :: Message -> TcM a -- Add an error message and fail
failWithTc err_msg = failWithTcM (emptyTidyEnv, err_msg)
-addErrTc :: Message -> NF_TcM s ()
+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 s a -- Add an error message and fail
+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 s () -- Check that the boolean is true
+checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
checkTc True err = returnTc ()
checkTc False err = failWithTc err
-checkTcM :: Bool -> TcM s () -> TcM s () -- Check that the boolean is true
+checkTcM :: Bool -> TcM () -> TcM () -- Check that the boolean is true
checkTcM True err = returnTc ()
checkTcM False err = err
-checkMaybeTc :: Maybe val -> Message -> TcM s val
+checkMaybeTc :: Maybe val -> Message -> TcM val
checkMaybeTc (Just val) err = returnTc val
checkMaybeTc Nothing err = failWithTc err
-checkMaybeTcM :: Maybe val -> TcM s val -> TcM s val
+checkMaybeTcM :: Maybe val -> TcM val -> TcM val
checkMaybeTcM (Just val) err = returnTc val
checkMaybeTcM Nothing err = err
-addErrTcM :: (TidyEnv, Message) -> NF_TcM s () -- Add an error message but don't fail
+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
writeIORef errs_var (warns, errs `snocBag` err)
where
errs_var = getTcErrs down
- ctxt = getErrCtxt down
- loc = getLoc down
do_ctxt tidy_env [] down env
= return []
return (m:ms)
-- warnings don't have an 'M' variant
-warnTc :: Bool -> Message -> NF_TcM s ()
+warnTc :: Bool -> Message -> NF_TcM ()
warnTc warn_if_true warn_msg down env
| warn_if_true
= do
-- (it might have recovered internally)
-- If so, then r is invoked, passing the warnings and errors from m
-tryTc :: ((Bag WarnMsg, Bag ErrMsg) -> TcM s r) -- Recovery action
- -> TcM s r -- Thing to try
- -> TcM s r
+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
+
my_recover m_errs_var
= do warns_and_errs <- readIORef m_errs_var
recover warns_and_errs down env
-- errors along the way.
(m_warns, m_errs) <- readIORef m_errs_var
if isEmptyBag m_errs then
- return result
+ -- 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
-- (it might have recovered internally)
-- If so, it fails too.
-- Regardless, any errors generated by m are propagated to the enclosing context.
-checkNoErrsTc :: TcM s r -> TcM s r
+checkNoErrsTc :: TcM r -> TcM r
checkNoErrsTc main
= tryTc my_recover main
where
-- (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_ :: TcM r -> TcM r -> TcM r
tryTc_ recover main
= tryTc my_recover main
where
my_recover warns_and_errs = recover
-- (discardErrsTc m) runs m, but throw away all its error messages.
-discardErrsTc :: Either_TcM s r -> Either_TcM s r
+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}
-Mutable variables
-~~~~~~~~~~~~~~~~~
+
+
+%************************************************************************
+%* *
+\subsection{Mutable variables}
+%* *
+%************************************************************************
+
\begin{code}
-tcNewMutVar :: a -> NF_TcM s (TcRef a)
+tcNewMutVar :: a -> NF_TcM (TcRef a)
tcNewMutVar val down env = newIORef val
-tcWriteMutVar :: TcRef a -> a -> NF_TcM s ()
+tcWriteMutVar :: TcRef a -> a -> NF_TcM ()
tcWriteMutVar var val down env = writeIORef var val
-tcReadMutVar :: TcRef a -> NF_TcM s a
+tcReadMutVar :: TcRef a -> NF_TcM a
tcReadMutVar var down env = readIORef var
-tcNewMutTyVar :: Name -> Kind -> NF_TcM s TyVar
-tcNewMutTyVar name kind down env = newMutTyVar name kind
-
-tcNewSigTyVar :: Name -> Kind -> NF_TcM s TyVar
-tcNewSigTyVar name kind down env = newSigTyVar name kind
+tcNewMutTyVar :: Name -> Kind -> TyVarDetails -> NF_TcM TyVar
+tcNewMutTyVar name kind details down env = newMutTyVar name kind details
-tcReadMutTyVar :: TyVar -> NF_TcM s (Maybe Type)
+tcReadMutTyVar :: TyVar -> NF_TcM (Maybe Type)
tcReadMutTyVar tyvar down env = readMutTyVar tyvar
-tcWriteMutTyVar :: TyVar -> Maybe Type -> NF_TcM s ()
+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
+tcGetEnv :: NF_TcM TcEnv
tcGetEnv down env = return env
-tcSetEnv :: TcEnv -> Either_TcM s a -> Either_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 :: 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 -> Either_TcM s a -> Either_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 :: NF_TcM SrcLoc
tcGetSrcLoc down env = return (getLoc down)
-tcSetErrCtxtM, tcAddErrCtxtM :: (TidyEnv -> NF_TcM s (TidyEnv, 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 -> Either_TcM s r -> Either_TcM s r
+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
= do uniq_supply <- readIORef u_var
let (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
where
u_var = getUniqSupplyVar down
-tcGetUniques :: Int -> NF_TcM s [Unique]
-tcGetUniques n down env
+tcGetUniques :: NF_TcM [Unique]
+tcGetUniques down env
= do uniq_supply <- readIORef u_var
let (new_uniq_supply, uniq_s) = splitUniqSupply uniq_supply
- uniqs = uniqsFromSupply n uniq_s
+ uniqs = uniqsFromSupply uniq_s
writeIORef u_var new_uniq_supply
return uniqs
where
u_var = getUniqSupplyVar down
-uniqSMToTcM :: UniqSM a -> NF_TcM s a
+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
\end{code}
-\section{TcDown}
-%~~~~~~~~~~~~~~~
+
+%************************************************************************
+%* *
+\subsection{TcDown}
+%* *
+%************************************************************************
\begin{code}
data TcDown
- = TcDown
- [Type] -- Types used for defaulting
-
- (TcRef UniqSupply) -- Unique supply
-
- SrcLoc -- Source location
- ErrCtxt -- Error context
- (TcRef (Bag WarnMsg,
- Bag ErrMsg))
-
-type ErrCtxt = [TidyEnv -> NF_TcM Unused (TidyEnv, Message)]
+ = 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
-- 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}
+
+getLoc (TcDown{tc_loc=loc}) = loc
+setLoc down loc = down{tc_loc=loc}
+
+getUniqSupplyVar (TcDown{tc_us=us}) = us
-getDefaultTys (TcDown def us loc ctxt errs) = def
-setDefaultTys (TcDown _ us loc ctxt errs) def = TcDown def us loc ctxt errs
+getErrCtxt (TcDown{tc_ctxt=ctxt}) = ctxt
+setErrCtxt down msg = down{tc_ctxt=[msg]}
+addErrCtxt down msg = down{tc_ctxt = msg : tc_ctxt down}
-getLoc (TcDown def us loc ctxt errs) = loc
-setLoc (TcDown def us _ ctxt errs) loc = TcDown def us loc ctxt errs
+popErrCtxt down = case tc_ctxt down of
+ [] -> down
+ m : ms -> down{tc_ctxt = ms}
-getUniqSupplyVar (TcDown def us loc ctxt errs) = us
+doptsTc :: DynFlag -> NF_TcM Bool
+doptsTc dflag (TcDown{tc_dflags=dflags}) env_down
+ = return (dopt dflag dflags)
-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
+getDOptsTc :: NF_TcM DynFlags
+getDOptsTc (TcDown{tc_dflags=dflags}) env_down
+ = return dflags
\end{code}
-TypeChecking Errors
-~~~~~~~~~~~~~~~~~~~
+%************************************************************************
+%* *
+\subsection{TypeChecking Errors}
+%* *
+%************************************************************************
\begin{code}
type TcError = Message
type TcWarning = Message
ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
- | otherwise = takeAtMost 3 ctxt
- where
- takeAtMost :: Int -> [a] -> [a]
- takeAtMost 0 ls = []
- takeAtMost n [] = []
- takeAtMost n (x:xs) = x:takeAtMost (n-1) xs
+ | otherwise = take 3 ctxt
arityErr kind name n m
= hsep [ text kind, quotes (ppr name), ptext SLIT("should have"),
\end{code}
+
+%************************************************************************
+%* *
+\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}
+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
+ 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