[project @ 2001-11-19 16:34:12 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcMonad.lhs

diff --git a/ghc/compiler/typecheck/TcMonad.lhs b/ghc/compiler/typecheck/TcMonad.lhs
index acbfd15..d613e07 100644 (file)
--- a/ghc/compiler/typecheck/TcMonad.lhs
+++ b/ghc/compiler/typecheck/TcMonad.lhs
@@ -1,10 +1,5 @@
 \begin{code}
 module TcMonad(
-       TcType, 
-       TcTauType, TcPredType, TcThetaType, TcRhoType,
-       TcTyVar, TcTyVarSet,
-       TcKind,
-
        TcM, NF_TcM, TcDown, TcEnv, 
 
        initTc,
@@ -32,9 +27,9 @@ module TcMonad(
 
        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, 
@@ -47,19 +42,17 @@ module TcMonad(
 
 import {-# SOURCE #-} TcEnv  ( TcEnv )
 
-import HsSyn           ( HsOverLit )
+import HsLit           ( HsOverLit )
 import RnHsSyn         ( RenamedPat, RenamedArithSeqInfo, RenamedHsExpr )
-import Type            ( Type, Kind, PredType, ThetaType, RhoType, TauType,
-                       )
+import TcType          ( Type, Kind, TyVarDetails )
 import ErrUtils                ( addShortErrLocLine, addShortWarnLocLine, ErrMsg, Message, WarnMsg )
 
 import Bag             ( Bag, emptyBag, isEmptyBag,
                          foldBag, unitBag, unionBags, snocBag )
 import Class           ( Class )
 import Name            ( Name )
-import Var             ( Id, TyVar, newMutTyVar, newSigTyVar, readMutTyVar, writeMutTyVar )
+import Var             ( Id, TyVar, newMutTyVar, readMutTyVar, writeMutTyVar )
 import VarEnv          ( TidyEnv, emptyTidyEnv )
-import VarSet          ( TyVarSet )
 import UniqSupply      ( UniqSupply, uniqFromSupply, uniqsFromSupply, 
                          splitUniqSupply, mkSplitUniqSupply,
                          UniqSM, initUs_ )
@@ -80,30 +73,6 @@ infixr 9 `thenTc`, `thenTc_`, `thenNF_Tc`, `thenNF_Tc_`
 
 %************************************************************************
 %*                                                                     *
-\subsection{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 TcPredType     = PredType
-type TcThetaType    = ThetaType
-type TcRhoType      = RhoType
-type TcTauType      = TauType
-type TcKind         = TcType
-\end{code}
-
-
-%************************************************************************
-%*                                                                     *
 \subsection{The main monads: TcM, NF_TcM}
 %*                                                                     *
 %************************************************************************
@@ -298,7 +267,7 @@ 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 a                 -- Add an error message and fail
 failWithTc err_msg = failWithTcM (emptyTidyEnv, err_msg)
@@ -394,6 +363,8 @@ tryTc recover main down env
        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
@@ -406,7 +377,13 @@ tryTc recover main 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
 
@@ -464,11 +441,8 @@ tcWriteMutVar var val down env = writeIORef var val
 tcReadMutVar :: TcRef a -> NF_TcM a
 tcReadMutVar var down env = readIORef var
 
-tcNewMutTyVar :: Name -> Kind -> NF_TcM TyVar
-tcNewMutTyVar name kind down env = newMutTyVar name kind
-
-tcNewSigTyVar :: Name -> Kind -> NF_TcM 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 (Maybe Type)
 tcReadMutTyVar tyvar down env = readMutTyVar tyvar
@@ -524,6 +498,9 @@ 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}
 
 
@@ -544,11 +521,11 @@ tcGetUnique down env
   where
     u_var = getUniqSupplyVar down
 
-tcGetUniques :: Int -> NF_TcM [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
@@ -607,6 +584,10 @@ getErrCtxt (TcDown{tc_ctxt=ctxt}) = ctxt
 setErrCtxt down msg = down{tc_ctxt=[msg]}
 addErrCtxt down msg = down{tc_ctxt = msg : tc_ctxt down}
 
+popErrCtxt down = case tc_ctxt down of
+                       []     -> down
+                       m : ms -> down{tc_ctxt = ms}
+
 doptsTc :: DynFlag -> TcM Bool
 doptsTc dflag (TcDown{tc_dflags=dflags}) env_down
    = return (dopt dflag dflags)
@@ -630,12 +611,7 @@ 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"),
@@ -725,12 +701,16 @@ pprInstLoc (orig, locn, ctxt)
        = 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 (InstanceDeclOrigin)
-       =  ptext SLIT("an instance declaration")
     pp_orig (ArithSeqOrigin seq)
        = hsep [ptext SLIT("the arithmetic sequence"), quotes (ppr seq)]
     pp_orig (SignatureOrigin)