GlobalRdrEnv, LocalRdrEnv, NameCache, FixityEnv,
GhciMode, lookupType, unQualInScope )
import TcRnTypes
-import Module ( Module, moduleName, unitModuleEnv, foldModuleEnv )
+import Module ( Module, unitModuleEnv, foldModuleEnv )
import Name ( Name, isInternalName )
import Type ( Type )
import NameEnv ( extendNameEnvList )
import CmdLineOpts ( DynFlags, DynFlag(..), dopt, opt_PprStyle_Debug )
import BasicTypes ( FixitySig )
import Bag ( snocBag, unionBags )
-
+import Panic ( showException )
+
import Maybe ( isJust )
import IO ( stderr )
import DATA_IOREF ( newIORef, readIORef )
+import EXCEPTION ( Exception )
\end{code}
%************************************************************************
usg_var <- newIORef emptyUsages ;
nc_var <- newIORef (pcs_nc pcs) ;
eps_var <- newIORef eps ;
-
+ ie_var <- newIORef (mkImpInstEnv dflags eps hpt) ;
+
let {
env = Env { env_top = top_env,
env_gbl = gbl_env,
tcg_fix_env = emptyFixityEnv,
tcg_default = defaultDefaultTys,
tcg_type_env = emptyNameEnv,
- tcg_ist = mkImpTypeEnv eps hpt,
- tcg_inst_env = mkImpInstEnv dflags eps hpt,
+ tcg_inst_env = ie_var,
tcg_exports = [],
tcg_imports = init_imports,
tcg_binds = EmptyMonoBinds,
tcg_fords = [] } ;
lcl_env = TcLclEnv {
- tcl_ctxt = [],
- tcl_level = topStage,
- tcl_env = emptyNameEnv,
- tcl_tyvars = tvs_var,
- tcl_lie = panic "initTc:LIE" } ;
+ tcl_ctxt = [],
+ tcl_th_ctxt = topStage,
+ tcl_arrow_ctxt = topArrowCtxt,
+ tcl_env = emptyNameEnv,
+ tcl_tyvars = tvs_var,
+ tcl_lie = panic "initTc:LIE" } ;
-- LIE only valid inside a getLIE
} ;
defaultDefaultTys = [integerTy, doubleTy]
mkImpInstEnv :: DynFlags -> ExternalPackageState -> HomePackageTable -> InstEnv
+-- At the moment we (wrongly) build an instance environment from all the
+-- modules we have already compiled:
+-- (a) eps_inst_env from the external package state
+-- (b) all the md_insts in the home package table
+-- We should really only get instances from modules below us in the
+-- module import tree.
mkImpInstEnv dflags eps hpt
= foldModuleEnv (add . md_insts . hm_details)
(eps_inst_env eps)
setLclEnv :: m -> TcRn m a -> TcRn n a
setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
+
+getEnvs :: TcRn m (TcGblEnv, m)
+getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
+
+setEnvs :: (TcGblEnv, m) -> TcRn m a -> TcRn m a
+setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
\end{code}
+
Command-line flags
\begin{code}
(warns, errs) <- readMutVar errs_var ;
writeMutVar errs_var (warns `unionBags` m_warns,
errs `unionBags` m_errs) }
-
-checkGHCI :: Message -> TcRn m () -- Check that GHCI is on
- -- otherwise add the error message
-#ifdef GHCI
-checkGHCI m = returnM ()
-#else
-checkGHCI m = addErr m
-#endif
\end{code}
-> TcRn m r -- Main action: do this first
-> TcRn m r
recoverM recover thing
- = do { mb_res <- tryM thing ;
+ = do { mb_res <- try_m thing ;
case mb_res of
Left exn -> recover
Right res -> returnM res }
tryTc m
= do { errs_var <- newMutVar emptyMessages ;
- mb_r <- tryM (setErrsVar errs_var m) ;
+ mb_r <- try_m (setErrsVar errs_var m) ;
new_errs <- readMutVar errs_var ;
return (new_errs,
case mb_r of
- Left exn -> Nothing
+ Left exn -> Nothing
Right r | errorsFound dflags new_errs -> Nothing
| otherwise -> Just r)
}
+try_m :: TcRn m r -> TcRn m (Either Exception r)
+-- Does try_m, with a debug-trace on failure
+try_m thing
+ = do { mb_r <- tryM thing ;
+ case mb_r of
+ Left exn -> do { traceTc (exn_msg exn); return mb_r }
+ Right r -> return mb_r }
+ where
+ exn_msg exn = text "recoverM recovering from" <+> text (showException exn)
+
tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
-- Just like tryTc, except that it ensures that the LIE
-- for the thing is propagated only if there are no errors
return (errs, mb_r) }
tryTcLIE_ :: TcM r -> TcM r -> TcM r
--- (tryM_ r m) tries m; if it succeeds it returns it,
+-- (tryTcLIE_ 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.
tryTcLIE_ recover main
-- Run thing_inside in an interleaved thread. It gets a separate
-- * errs_var, and
-- * unique supply,
+-- * LIE var is set to bottom (should never be used)
-- but everything else is shared, so this is DANGEROUS.
--
-- It returns Nothing if the computation fails
= do { us <- newUniqueSupply ;
unsafeInterleaveM $
do { us_var <- newMutVar us ;
- (msgs, mb_res) <- tryTcLIE (setUsVar us_var thing_inside) ;
+ (msgs, mb_res) <- tryTc (setLIEVar (panic "forkM: LIE used") $
+ setUsVar us_var thing_inside) ;
case mb_res of
Just r -> return (Just r)
Nothing -> do {
- -- Bleat about errors in the forked thread
- ioToTcRn (do { printErrs (hdr_doc defaultErrStyle) ;
- printErrorsAndWarnings msgs }) ;
+
+ -- Bleat about errors in the forked thread, if -ddump-tc-trace is on
+ -- Otherwise we silently discard errors. Errors can legitimately
+ -- happen when compiling interface signatures (see tcInterfaceSigs)
+ ifOptM Opt_D_dump_tc_trace
+ (ioToTcRn (do { printErrs (hdr_doc defaultErrStyle) ;
+ printErrorsAndWarnings msgs })) ;
+
return Nothing }
}}
where
%************************************************************************
%* *
- Other stuff specific to type checker
+ Type constraints (the so-called LIE)
%* *
%************************************************************************
writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
\end{code}
-
\begin{code}
-getStage :: TcM Stage
-getStage = do { env <- getLclEnv; return (tcl_level env) }
-
-setStage :: Stage -> TcM a -> TcM a
-setStage s = updLclEnv (\ env -> env { tcl_level = s })
-
setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
-- Set the local type envt, but do *not* disturb other fields,
-- notably the lie_var
%************************************************************************
%* *
+ Template Haskell context
+%* *
+%************************************************************************
+
+\begin{code}
+getStage :: TcM ThStage
+getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
+
+setStage :: ThStage -> TcM a -> TcM a
+setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
+\end{code}
+
+
+%************************************************************************
+%* *
+ Arrow context
+%* *
+%************************************************************************
+
+\begin{code}
+popArrowBinders :: TcM a -> TcM a -- Move to the left of a (-<); see comments in TcRnTypes
+popArrowBinders
+ = updLclEnv (\ env -> env { tcl_arrow_ctxt = pop (tcl_arrow_ctxt env) })
+ where
+ pop (ArrCtxt {proc_level = curr_lvl, proc_banned = banned})
+ = ASSERT( not (curr_lvl `elem` banned) )
+ ArrCtxt {proc_level = curr_lvl, proc_banned = curr_lvl : banned}
+
+getBannedProcLevels :: TcM [ProcLevel]
+ = do { env <- getLclEnv; return (proc_banned (tcl_arrow_ctxt env)) }
+
+incProcLevel :: TcM a -> TcM a
+incProcLevel
+ = updLclEnv (\ env -> env { tcl_arrow_ctxt = inc (tcl_arrow_ctxt env) })
+ where
+ inc ctxt = ctxt { proc_level = proc_level ctxt + 1 }
+\end{code}
+
+
+%************************************************************************
+%* *
Stuff for the renamer's local env
%* *
%************************************************************************
\begin{code}
initRn :: RnMode -> RnM a -> TcRn m a
initRn mode thing_inside
- = do { env <- getGblEnv ;
- let { lcl_env = RnLclEnv {
+ = do { let { lcl_env = RnLclEnv {
rn_mode = mode,
rn_lenv = emptyRdrEnv }} ;
setLclEnv lcl_env thing_inside }