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% (c) The University of Glasgow 2006
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#include "HsVersions.h"
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import TcRnTypes -- Re-export all
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import IOEnv -- Re-export all
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import HsSyn hiding (LIE)
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import qualified Data.Set as Set
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%************************************************************************
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%************************************************************************
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-> Bool -- True <=> retain renamed syntax trees
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-> IO (Messages, Maybe r)
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-- Nothing => error thrown by the thing inside
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-- (error messages should have been printed already)
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initTc hsc_env hsc_src keep_rn_syntax mod do_this
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= do { errs_var <- newIORef (emptyBag, emptyBag) ;
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meta_var <- newIORef initTyVarUnique ;
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tvs_var <- newIORef emptyVarSet ;
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dfuns_var <- newIORef emptyNameSet ;
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keep_var <- newIORef emptyNameSet ;
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used_rdr_var <- newIORef Set.empty ;
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th_var <- newIORef False ;
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lie_var <- newIORef emptyBag ;
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dfun_n_var <- newIORef emptyOccSet ;
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type_env_var <- case hsc_type_env_var hsc_env of {
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Just (_mod, te_var) -> return te_var ;
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Nothing -> newIORef emptyNameEnv } ;
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maybe_rn_syntax :: forall a. a -> Maybe a ;
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maybe_rn_syntax empty_val
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| keep_rn_syntax = Just empty_val
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| otherwise = Nothing ;
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tcg_rdr_env = emptyGlobalRdrEnv,
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tcg_fix_env = emptyNameEnv,
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tcg_field_env = RecFields emptyNameEnv emptyNameSet,
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tcg_default = Nothing,
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tcg_type_env = emptyNameEnv,
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tcg_type_env_var = type_env_var,
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tcg_inst_env = emptyInstEnv,
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tcg_fam_inst_env = emptyFamInstEnv,
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tcg_inst_uses = dfuns_var,
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tcg_th_used = th_var,
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tcg_imports = emptyImportAvails,
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tcg_used_rdrnames = used_rdr_var,
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tcg_rn_exports = maybe_rn_syntax [],
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tcg_rn_decls = maybe_rn_syntax emptyRnGroup,
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tcg_binds = emptyLHsBinds,
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tcg_sigs = emptyNameSet,
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tcg_ev_binds = emptyBag,
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tcg_warns = NoWarnings,
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tcg_dfun_n = dfun_n_var,
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tcg_doc_hdr = Nothing,
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tcl_loc = mkGeneralSrcSpan (fsLit "Top level"),
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tcl_rdr = emptyLocalRdrEnv,
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tcl_th_ctxt = topStage,
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tcl_arrow_ctxt = NoArrowCtxt,
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tcl_env = emptyNameEnv,
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tcl_tyvars = tvs_var,
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tcl_untch = initTyVarUnique
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-- OK, here's the business end!
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maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
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do { r <- tryM do_this
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Right res -> return (Just res)
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Left _ -> return Nothing } ;
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-- Check for unsolved constraints
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lie <- readIORef lie_var ;
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else pprPanic "initTc: unsolved constraints"
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(pprWantedsWithLocs lie) ;
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-- Collect any error messages
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msgs <- readIORef errs_var ;
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let { dflags = hsc_dflags hsc_env
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; final_res | errorsFound dflags msgs = Nothing
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| otherwise = maybe_res } ;
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return (msgs, final_res)
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initTcPrintErrors -- Used from the interactive loop only
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-> IO (Messages, Maybe r)
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initTcPrintErrors env mod todo = do
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(msgs, res) <- initTc env HsSrcFile False mod todo
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%************************************************************************
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%************************************************************************
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initTcRnIf :: Char -- Tag for unique supply
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initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
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= do { us <- mkSplitUniqSupply uniq_tag ;
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; us_var <- newIORef us ;
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; let { env = Env { env_top = hsc_env,
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; runIOEnv env thing_inside
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%************************************************************************
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%************************************************************************
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getTopEnv :: TcRnIf gbl lcl HscEnv
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getTopEnv = do { env <- getEnv; return (env_top env) }
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getGblEnv :: TcRnIf gbl lcl gbl
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getGblEnv = do { env <- getEnv; return (env_gbl env) }
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updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
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updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
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env { env_gbl = upd gbl })
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setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
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setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
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getLclEnv :: TcRnIf gbl lcl lcl
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getLclEnv = do { env <- getEnv; return (env_lcl env) }
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updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
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updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
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env { env_lcl = upd lcl })
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setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
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setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
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getEnvs :: TcRnIf gbl lcl (gbl, lcl)
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getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
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setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
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setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
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getDOpts :: TcRnIf gbl lcl DynFlags
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getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
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xoptM :: ExtensionFlag -> TcRnIf gbl lcl Bool
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xoptM flag = do { dflags <- getDOpts; return (xopt flag dflags) }
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doptM :: DynFlag -> TcRnIf gbl lcl Bool
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doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
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-- XXX setOptM and unsetOptM operate on different types. One should be renamed.
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setOptM :: ExtensionFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
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setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
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env { env_top = top { hsc_dflags = xopt_set (hsc_dflags top) flag}} )
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unsetOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
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unsetOptM flag = updEnv (\ env@(Env { env_top = top }) ->
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env { env_top = top { hsc_dflags = dopt_unset (hsc_dflags top) flag}} )
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-- | Do it flag is true
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ifDOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
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ifDOptM flag thing_inside = do { b <- doptM flag;
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if b then thing_inside else return () }
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ifXOptM :: ExtensionFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
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ifXOptM flag thing_inside = do { b <- xoptM flag;
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if b then thing_inside else return () }
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getGhcMode :: TcRnIf gbl lcl GhcMode
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getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
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getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
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getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
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getEps :: TcRnIf gbl lcl ExternalPackageState
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getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
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-- | Update the external package state. Returns the second result of the
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-- modifier function.
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-- This is an atomic operation and forces evaluation of the modified EPS in
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-- order to avoid space leaks.
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updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
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updateEps upd_fn = do
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traceIf (text "updating EPS")
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atomicUpdMutVar' eps_var upd_fn
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-- | Update the external package state.
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-- This is an atomic operation and forces evaluation of the modified EPS in
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-- order to avoid space leaks.
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updateEps_ :: (ExternalPackageState -> ExternalPackageState)
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updateEps_ upd_fn = do
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traceIf (text "updating EPS_")
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atomicUpdMutVar' eps_var (\eps -> (upd_fn eps, ()))
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getHpt :: TcRnIf gbl lcl HomePackageTable
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getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
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getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
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getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
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; return (eps, hsc_HPT env) }
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%************************************************************************
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%************************************************************************
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newMetaUnique :: TcM Unique
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-- The uniques for TcMetaTyVars are allocated specially
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-- in guaranteed linear order, starting at zero for each module
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= do { env <- getLclEnv
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; let meta_var = tcl_meta env
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; uniq <- readMutVar meta_var
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; writeMutVar meta_var (incrUnique uniq)
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newUnique :: TcRnIf gbl lcl Unique
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= do { env <- getEnv ;
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let { u_var = env_us env } ;
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us <- readMutVar u_var ;
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case splitUniqSupply us of { (us1,_) -> do {
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writeMutVar u_var us1 ;
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return $! uniqFromSupply us }}}
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-- NOTE 1: we strictly split the supply, to avoid the possibility of leaving
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-- a chain of unevaluated supplies behind.
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-- NOTE 2: we use the uniq in the supply from the MutVar directly, and
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-- throw away one half of the new split supply. This is safe because this
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-- is the only place we use that unique. Using the other half of the split
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-- supply is safer, but slower.
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newUniqueSupply :: TcRnIf gbl lcl UniqSupply
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= do { env <- getEnv ;
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let { u_var = env_us env } ;
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us <- readMutVar u_var ;
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case splitUniqSupply us of { (us1,us2) -> do {
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writeMutVar u_var us1 ;
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newLocalName :: Name -> TcRnIf gbl lcl Name
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newLocalName name -- Make a clone
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= do { uniq <- newUnique
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; return (mkInternalName uniq (nameOccName name) (getSrcSpan name)) }
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newSysLocalIds :: FastString -> [TcType] -> TcRnIf gbl lcl [TcId]
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newSysLocalIds fs tys
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= do { us <- newUniqueSupply
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; return (zipWith (mkSysLocal fs) (uniqsFromSupply us) tys) }
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instance MonadUnique (IOEnv (Env gbl lcl)) where
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getUniqueM = newUnique
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getUniqueSupplyM = newUniqueSupply
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%************************************************************************
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%************************************************************************
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newTcRef :: a -> TcRnIf gbl lcl (TcRef a)
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readTcRef :: TcRef a -> TcRnIf gbl lcl a
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readTcRef = readMutVar
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writeTcRef :: TcRef a -> a -> TcRnIf gbl lcl ()
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writeTcRef = writeMutVar
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updTcRef :: TcRef a -> (a -> a) -> TcRnIf gbl lcl ()
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%************************************************************************
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%************************************************************************
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traceTc :: String -> SDoc -> TcRn ()
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traceTcN :: Int -> String -> SDoc -> TcRn ()
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traceTcN level herald doc
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| level <= opt_TraceLevel = traceOptTcRn Opt_D_dump_tc_trace $
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hang (text herald) 2 doc
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| otherwise = return ()
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traceRn, traceSplice :: SDoc -> TcRn ()
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traceRn = traceOptTcRn Opt_D_dump_rn_trace
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traceSplice = traceOptTcRn Opt_D_dump_splices
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traceIf, traceHiDiffs :: SDoc -> TcRnIf m n ()
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traceIf = traceOptIf Opt_D_dump_if_trace
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traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
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traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
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traceOptIf flag doc = ifDOptM flag $
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liftIO (printForUser stderr alwaysQualify doc)
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traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
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-- Output the message, with current location if opt_PprStyle_Debug
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traceOptTcRn flag doc = ifDOptM flag $ do
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| opt_PprStyle_Debug = mkLocMessage loc doc
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| otherwise = doc -- The full location is
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-- usually way too much
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; dumpTcRn real_doc }
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dumpTcRn :: SDoc -> TcRn ()
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dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv
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; liftIO (printForUser stderr (mkPrintUnqualified dflags rdr_env) doc) }
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debugDumpTcRn :: SDoc -> TcRn ()
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debugDumpTcRn doc | opt_NoDebugOutput = return ()
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| otherwise = dumpTcRn doc
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dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
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dumpOptTcRn flag doc = ifDOptM flag (dumpTcRn doc)
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%************************************************************************
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Typechecker global environment
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%************************************************************************
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getModule :: TcRn Module
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getModule = do { env <- getGblEnv; return (tcg_mod env) }
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setModule :: Module -> TcRn a -> TcRn a
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setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
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tcIsHsBoot :: TcRn Bool
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tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
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getGlobalRdrEnv :: TcRn GlobalRdrEnv
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getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
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getRdrEnvs :: TcRn (GlobalRdrEnv, LocalRdrEnv)
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getRdrEnvs = do { (gbl,lcl) <- getEnvs; return (tcg_rdr_env gbl, tcl_rdr lcl) }
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getImports :: TcRn ImportAvails
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getImports = do { env <- getGblEnv; return (tcg_imports env) }
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getFixityEnv :: TcRn FixityEnv
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getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
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extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
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extendFixityEnv new_bit
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= updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
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env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
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getRecFieldEnv :: TcRn RecFieldEnv
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getRecFieldEnv = do { env <- getGblEnv; return (tcg_field_env env) }
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getDeclaredDefaultTys :: TcRn (Maybe [Type])
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getDeclaredDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
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%************************************************************************
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%************************************************************************
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getSrcSpanM :: TcRn SrcSpan
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-- Avoid clash with Name.getSrcLoc
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getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
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setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
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setSrcSpan loc thing_inside
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| isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
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| otherwise = thing_inside -- Don't overwrite useful info with useless
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addLocM :: (a -> TcM b) -> Located a -> TcM b
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addLocM fn (L loc a) = setSrcSpan loc $ fn a
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wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
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wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
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wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
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wrapLocFstM fn (L loc a) =
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wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
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wrapLocSndM fn (L loc a) =
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getErrsVar :: TcRn (TcRef Messages)
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getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
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setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
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setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
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addErr :: Message -> TcRn () -- Ignores the context stack
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addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
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failWith :: Message -> TcRn a
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failWith msg = addErr msg >> failM
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addErrAt :: SrcSpan -> Message -> TcRn ()
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-- addErrAt is mainly (exclusively?) used by the renamer, where
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-- tidying is not an issue, but it's all lazy so the extra
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-- work doesn't matter
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addErrAt loc msg = do { ctxt <- getErrCtxt
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; tidy_env <- tcInitTidyEnv
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; err_info <- mkErrInfo tidy_env ctxt
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; addLongErrAt loc msg err_info }
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addErrs :: [(SrcSpan,Message)] -> TcRn ()
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addErrs msgs = mapM_ add msgs
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add (loc,msg) = addErrAt loc msg
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addWarn :: Message -> TcRn ()
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addWarn msg = addReport (ptext (sLit "Warning:") <+> msg) empty
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addWarnAt :: SrcSpan -> Message -> TcRn ()
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addWarnAt loc msg = addReportAt loc (ptext (sLit "Warning:") <+> msg) empty
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checkErr :: Bool -> Message -> TcRn ()
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-- Add the error if the bool is False
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checkErr ok msg = unless ok (addErr msg)
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warnIf :: Bool -> Message -> TcRn ()
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warnIf True msg = addWarn msg
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warnIf False _ = return ()
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addMessages :: Messages -> TcRn ()
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addMessages (m_warns, m_errs)
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= do { errs_var <- getErrsVar ;
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(warns, errs) <- readTcRef errs_var ;
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writeTcRef errs_var (warns `unionBags` m_warns,
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errs `unionBags` m_errs) }
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discardWarnings :: TcRn a -> TcRn a
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-- Ignore warnings inside the thing inside;
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-- used to ignore-unused-variable warnings inside derived code
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-- With -dppr-debug, the effects is switched off, so you can still see
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-- what warnings derived code would give
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discardWarnings thing_inside
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| opt_PprStyle_Debug = thing_inside
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= do { errs_var <- newTcRef emptyMessages
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; result <- setErrsVar errs_var thing_inside
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; (_warns, errs) <- readTcRef errs_var
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; addMessages (emptyBag, errs)
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%************************************************************************
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Shared error message stuff: renamer and typechecker
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%************************************************************************
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addReport :: Message -> Message -> TcRn ()
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addReport msg extra_info = do loc <- getSrcSpanM; addReportAt loc msg extra_info
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addReportAt :: SrcSpan -> Message -> Message -> TcRn ()
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addReportAt loc msg extra_info
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= do { errs_var <- getErrsVar ;
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rdr_env <- getGlobalRdrEnv ;
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let { warn = mkLongWarnMsg loc (mkPrintUnqualified dflags rdr_env)
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(warns, errs) <- readTcRef errs_var ;
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writeTcRef errs_var (warns `snocBag` warn, errs) }
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addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
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addLongErrAt loc msg extra
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= do { traceTc "Adding error:" (mkLocMessage loc (msg $$ extra)) ;
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errs_var <- getErrsVar ;
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rdr_env <- getGlobalRdrEnv ;
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let { err = mkLongErrMsg loc (mkPrintUnqualified dflags rdr_env) msg extra } ;
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(warns, errs) <- readTcRef errs_var ;
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writeTcRef errs_var (warns, errs `snocBag` err) }
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try_m :: TcRn r -> TcRn (Either IOEnvFailure r)
619
-- Does try_m, with a debug-trace on failure
621
= do { mb_r <- tryM thing ;
623
Left exn -> do { traceTc "tryTc/recoverM recovering from" $
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text (showException exn)
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Right _ -> return mb_r }
628
-----------------------
629
recoverM :: TcRn r -- Recovery action; do this if the main one fails
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-> TcRn r -- Main action: do this first
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-- Errors in 'thing' are retained
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recoverM recover thing
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= do { mb_res <- try_m thing ;
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Right res -> return res }
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-----------------------
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mapAndRecoverM :: (a -> TcRn b) -> [a] -> TcRn [b]
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-- Drop elements of the input that fail, so the result
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-- list can be shorter than the argument list
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mapAndRecoverM _ [] = return []
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mapAndRecoverM f (x:xs) = do { mb_r <- try_m (f x)
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; rs <- mapAndRecoverM f xs
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; return (case mb_r of
652
-----------------------
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tryTc :: TcRn a -> TcRn (Messages, Maybe a)
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-- (tryTc m) executes m, and returns
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-- Just r, if m succeeds (returning r)
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-- Nothing, if m fails
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-- It also returns all the errors and warnings accumulated by m
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-- It always succeeds (never raises an exception)
660
= do { errs_var <- newTcRef emptyMessages ;
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res <- try_m (setErrsVar errs_var m) ;
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msgs <- readTcRef errs_var ;
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return (msgs, case res of
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Right val -> Just val)
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-- The exception is always the IOEnv built-in
667
-- in exception; see IOEnv.failM
670
-----------------------
671
tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
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-- Run the thing, returning
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-- Just r, if m succceeds with no error messages
674
-- Nothing, if m fails, or if it succeeds but has error messages
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-- Either way, the messages are returned; even in the Just case
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-- there might be warnings
678
= do { (msgs, res) <- tryTc thing
680
; let errs_found = errorsFound dflags msgs
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; return (msgs, case res of
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Just val | errs_found -> Nothing
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| otherwise -> Just val)
687
-----------------------
688
tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
689
-- Just like tryTcErrs, except that it ensures that the LIE
690
-- for the thing is propagated only if there are no errors
691
-- Hence it's restricted to the type-check monad
692
tryTcLIE thing_inside
693
= do { ((msgs, mb_res), lie) <- captureConstraints (tryTcErrs thing_inside) ;
695
Nothing -> return (msgs, Nothing)
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Just val -> do { emitConstraints lie; return (msgs, Just val) }
699
-----------------------
700
tryTcLIE_ :: TcM r -> TcM r -> TcM r
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-- (tryTcLIE_ r m) tries m;
702
-- if m succeeds with no error messages, it's the answer
703
-- otherwise tryTcLIE_ drops everything from m and tries r instead.
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tryTcLIE_ recover main
705
= do { (msgs, mb_res) <- tryTcLIE main
707
Just val -> do { addMessages msgs -- There might be warnings
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Nothing -> recover -- Discard all msgs
712
-----------------------
713
checkNoErrs :: TcM r -> TcM r
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-- (checkNoErrs m) succeeds iff m succeeds and generates no errors
715
-- If m fails then (checkNoErrsTc m) fails.
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-- If m succeeds, it checks whether m generated any errors messages
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-- (it might have recovered internally)
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-- If so, it fails too.
719
-- Regardless, any errors generated by m are propagated to the enclosing context.
721
= do { (msgs, mb_res) <- tryTcLIE main
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Just val -> return val
728
ifErrsM :: TcRn r -> TcRn r -> TcRn r
729
-- ifErrsM bale_out main
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-- does 'bale_out' if there are errors in errors collection
731
-- otherwise does 'main'
732
ifErrsM bale_out normal
733
= do { errs_var <- getErrsVar ;
734
msgs <- readTcRef errs_var ;
736
if errorsFound dflags msgs then
741
failIfErrsM :: TcRn ()
742
-- Useful to avoid error cascades
743
failIfErrsM = ifErrsM failM (return ())
747
%************************************************************************
749
Context management for the type checker
751
%************************************************************************
754
getErrCtxt :: TcM [ErrCtxt]
755
getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
757
setErrCtxt :: [ErrCtxt] -> TcM a -> TcM a
758
setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
760
addErrCtxt :: Message -> TcM a -> TcM a
761
addErrCtxt msg = addErrCtxtM (\env -> return (env, msg))
763
addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
764
addErrCtxtM ctxt = updCtxt (\ ctxts -> (False, ctxt) : ctxts)
766
addLandmarkErrCtxt :: Message -> TcM a -> TcM a
767
addLandmarkErrCtxt msg = updCtxt (\ctxts -> (True, \env -> return (env,msg)) : ctxts)
769
-- Helper function for the above
770
updCtxt :: ([ErrCtxt] -> [ErrCtxt]) -> TcM a -> TcM a
771
updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
772
env { tcl_ctxt = upd ctxt })
774
-- Conditionally add an error context
775
maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
776
maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
777
maybeAddErrCtxt Nothing thing_inside = thing_inside
779
popErrCtxt :: TcM a -> TcM a
780
popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (_ : ms) -> ms })
782
getCtLoc :: orig -> TcM (CtLoc orig)
784
= do { loc <- getSrcSpanM ; env <- getLclEnv ;
785
return (CtLoc origin loc (tcl_ctxt env)) }
787
setCtLoc :: CtLoc orig -> TcM a -> TcM a
788
setCtLoc (CtLoc _ src_loc ctxt) thing_inside
789
= setSrcSpan src_loc (setErrCtxt ctxt thing_inside)
792
%************************************************************************
794
Error message generation (type checker)
796
%************************************************************************
798
The addErrTc functions add an error message, but do not cause failure.
799
The 'M' variants pass a TidyEnv that has already been used to
800
tidy up the message; we then use it to tidy the context messages
803
addErrTc :: Message -> TcM ()
804
addErrTc err_msg = do { env0 <- tcInitTidyEnv
805
; addErrTcM (env0, err_msg) }
807
addErrsTc :: [Message] -> TcM ()
808
addErrsTc err_msgs = mapM_ addErrTc err_msgs
810
addErrTcM :: (TidyEnv, Message) -> TcM ()
811
addErrTcM (tidy_env, err_msg)
812
= do { ctxt <- getErrCtxt ;
814
add_err_tcm tidy_env err_msg loc ctxt }
817
The failWith functions add an error message and cause failure
820
failWithTc :: Message -> TcM a -- Add an error message and fail
822
= addErrTc err_msg >> failM
824
failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
825
failWithTcM local_and_msg
826
= addErrTcM local_and_msg >> failM
828
checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
829
checkTc True _ = return ()
830
checkTc False err = failWithTc err
833
Warnings have no 'M' variant, nor failure
836
addWarnTc :: Message -> TcM ()
837
addWarnTc msg = do { env0 <- tcInitTidyEnv
838
; addWarnTcM (env0, msg) }
840
addWarnTcM :: (TidyEnv, Message) -> TcM ()
841
addWarnTcM (env0, msg)
842
= do { ctxt <- getErrCtxt ;
843
err_info <- mkErrInfo env0 ctxt ;
844
addReport (ptext (sLit "Warning:") <+> msg) err_info }
846
warnTc :: Bool -> Message -> TcM ()
847
warnTc warn_if_true warn_msg
848
| warn_if_true = addWarnTc warn_msg
849
| otherwise = return ()
852
-----------------------------------
855
We initialise the "tidy-env", used for tidying types before printing,
856
by building a reverse map from the in-scope type variables to the
857
OccName that the programmer originally used for them
860
tcInitTidyEnv :: TcM TidyEnv
862
= do { lcl_env <- getLclEnv
863
; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
864
| ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
866
; return (foldl add emptyTidyEnv nm_tv_prs) }
868
add (env,subst) (name, tyvar)
869
= case tidyOccName env (nameOccName name) of
870
(env', occ') -> (env', extendVarEnv subst tyvar tyvar')
872
tyvar' = setTyVarName tyvar name'
873
name' = tidyNameOcc name occ'
876
-----------------------------------
877
Other helper functions
880
add_err_tcm :: TidyEnv -> Message -> SrcSpan
883
add_err_tcm tidy_env err_msg loc ctxt
884
= do { err_info <- mkErrInfo tidy_env ctxt ;
885
addLongErrAt loc err_msg err_info }
887
mkErrInfo :: TidyEnv -> [ErrCtxt] -> TcM SDoc
888
-- Tidy the error info, trimming excessive contexts
892
go :: Int -> TidyEnv -> [ErrCtxt] -> TcM SDoc
893
go _ _ [] = return empty
894
go n env ((is_landmark, ctxt) : ctxts)
895
| is_landmark || n < mAX_CONTEXTS -- Too verbose || opt_PprStyle_Debug
896
= do { (env', msg) <- ctxt env
897
; let n' = if is_landmark then n else n+1
898
; rest <- go n' env' ctxts
899
; return (msg $$ rest) }
903
mAX_CONTEXTS :: Int -- No more than this number of non-landmark contexts
907
debugTc is useful for monadic debugging code
910
debugTc :: TcM () -> TcM ()
913
| otherwise = return ()
916
%************************************************************************
920
%************************************************************************
923
newTcEvBinds :: TcM EvBindsVar
924
newTcEvBinds = do { ref <- newTcRef emptyEvBindMap
926
; return (EvBindsVar ref uniq) }
928
extendTcEvBinds :: TcEvBinds -> EvVar -> EvTerm -> TcM TcEvBinds
929
extendTcEvBinds binds@(TcEvBinds binds_var) var rhs
930
= do { addTcEvBind binds_var var rhs
932
extendTcEvBinds (EvBinds bnds) var rhs
933
= return (EvBinds (bnds `snocBag` EvBind var rhs))
935
addTcEvBind :: EvBindsVar -> EvVar -> EvTerm -> TcM ()
936
-- Add a binding to the TcEvBinds by side effect
937
addTcEvBind (EvBindsVar ev_ref _) var rhs
938
= do { bnds <- readTcRef ev_ref
939
; writeTcRef ev_ref (extendEvBinds bnds var rhs) }
941
chooseUniqueOccTc :: (OccSet -> OccName) -> TcM OccName
942
chooseUniqueOccTc fn =
943
do { env <- getGblEnv
944
; let dfun_n_var = tcg_dfun_n env
945
; set <- readTcRef dfun_n_var
947
; writeTcRef dfun_n_var (extendOccSet set occ)
950
getConstraintVar :: TcM (TcRef WantedConstraints)
951
getConstraintVar = do { env <- getLclEnv; return (tcl_lie env) }
953
setConstraintVar :: TcRef WantedConstraints -> TcM a -> TcM a
954
setConstraintVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
956
emitConstraints :: WantedConstraints -> TcM ()
958
= do { lie_var <- getConstraintVar ;
959
updTcRef lie_var (`andWanteds` ct) }
961
emitConstraint :: WantedConstraint -> TcM ()
963
= do { lie_var <- getConstraintVar ;
964
updTcRef lie_var (`extendWanteds` ct) }
966
captureConstraints :: TcM a -> TcM (a, WantedConstraints)
967
-- (captureConstraints m) runs m, and returns the type constraints it generates
968
captureConstraints thing_inside
969
= do { lie_var <- newTcRef emptyWanteds ;
970
res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
972
lie <- readTcRef lie_var ;
975
captureUntouchables :: TcM a -> TcM (a, Untouchables)
976
captureUntouchables thing_inside
977
= do { env <- getLclEnv
978
; low_meta <- readTcRef (tcl_meta env)
979
; res <- setLclEnv (env { tcl_untch = low_meta })
981
; high_meta <- readTcRef (tcl_meta env)
982
; return (res, TouchableRange low_meta high_meta) }
984
isUntouchable :: TcTyVar -> TcM Bool
985
isUntouchable tv = do { env <- getLclEnv
986
; return (varUnique tv < tcl_untch env) }
988
getLclTypeEnv :: TcM (NameEnv TcTyThing)
989
getLclTypeEnv = do { env <- getLclEnv; return (tcl_env env) }
991
setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
992
-- Set the local type envt, but do *not* disturb other fields,
993
-- notably the lie_var
994
setLclTypeEnv lcl_env thing_inside
995
= updLclEnv upd thing_inside
997
upd env = env { tcl_env = tcl_env lcl_env,
998
tcl_tyvars = tcl_tyvars lcl_env }
1002
%************************************************************************
1004
Template Haskell context
1006
%************************************************************************
1009
recordThUse :: TcM ()
1010
recordThUse = do { env <- getGblEnv; writeTcRef (tcg_th_used env) True }
1012
keepAliveTc :: Id -> TcM () -- Record the name in the keep-alive set
1014
| isLocalId id = do { env <- getGblEnv;
1015
; updTcRef (tcg_keep env) (`addOneToNameSet` idName id) }
1016
| otherwise = return ()
1018
keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
1019
keepAliveSetTc ns = do { env <- getGblEnv;
1020
; updTcRef (tcg_keep env) (`unionNameSets` ns) }
1022
getStage :: TcM ThStage
1023
getStage = do { env <- getLclEnv; return (tcl_th_ctxt env) }
1025
setStage :: ThStage -> TcM a -> TcM a
1026
setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
1030
%************************************************************************
1032
Stuff for the renamer's local env
1034
%************************************************************************
1037
getLocalRdrEnv :: RnM LocalRdrEnv
1038
getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
1040
setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
1041
setLocalRdrEnv rdr_env thing_inside
1042
= updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
1046
%************************************************************************
1048
Stuff for interface decls
1050
%************************************************************************
1053
mkIfLclEnv :: Module -> SDoc -> IfLclEnv
1054
mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
1056
if_tv_env = emptyUFM,
1057
if_id_env = emptyUFM }
1059
initIfaceTcRn :: IfG a -> TcRn a
1060
initIfaceTcRn thing_inside
1061
= do { tcg_env <- getGblEnv
1062
; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
1063
; get_type_env = readTcRef (tcg_type_env_var tcg_env) }
1064
; setEnvs (if_env, ()) thing_inside }
1066
initIfaceExtCore :: IfL a -> TcRn a
1067
initIfaceExtCore thing_inside
1068
= do { tcg_env <- getGblEnv
1069
; let { mod = tcg_mod tcg_env
1070
; doc = ptext (sLit "External Core file for") <+> quotes (ppr mod)
1071
; if_env = IfGblEnv {
1072
if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
1073
; if_lenv = mkIfLclEnv mod doc
1075
; setEnvs (if_env, if_lenv) thing_inside }
1077
initIfaceCheck :: HscEnv -> IfG a -> IO a
1078
-- Used when checking the up-to-date-ness of the old Iface
1079
-- Initialise the environment with no useful info at all
1080
initIfaceCheck hsc_env do_this
1081
= do let rec_types = case hsc_type_env_var hsc_env of
1082
Just (mod,var) -> Just (mod, readTcRef var)
1084
gbl_env = IfGblEnv { if_rec_types = rec_types }
1085
initTcRnIf 'i' hsc_env gbl_env () do_this
1087
initIfaceTc :: ModIface
1088
-> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
1089
-- Used when type-checking checking an up-to-date interface file
1090
-- No type envt from the current module, but we do know the module dependencies
1091
initIfaceTc iface do_this
1092
= do { tc_env_var <- newTcRef emptyTypeEnv
1093
; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readTcRef tc_env_var) } ;
1094
; if_lenv = mkIfLclEnv mod doc
1096
; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
1099
mod = mi_module iface
1100
doc = ptext (sLit "The interface for") <+> quotes (ppr mod)
1102
initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
1103
-- Used when sucking in new Rules in SimplCore
1104
-- We have available the type envt of the module being compiled, and we must use it
1105
initIfaceRules hsc_env guts do_this
1107
type_info = (mg_module guts, return (mg_types guts))
1108
; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
1111
-- Run the thing; any exceptions just bubble out from here
1112
; initTcRnIf 'i' hsc_env gbl_env () do_this
1115
initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
1116
initIfaceLcl mod loc_doc thing_inside
1117
= setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
1119
getIfModule :: IfL Module
1120
getIfModule = do { env <- getLclEnv; return (if_mod env) }
1122
--------------------
1123
failIfM :: Message -> IfL a
1124
-- The Iface monad doesn't have a place to accumulate errors, so we
1125
-- just fall over fast if one happens; it "shouldnt happen".
1126
-- We use IfL here so that we can get context info out of the local env
1128
= do { env <- getLclEnv
1129
; let full_msg = (if_loc env <> colon) $$ nest 2 msg
1130
; liftIO (printErrs (full_msg defaultErrStyle))
1133
--------------------
1134
forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
1135
-- Run thing_inside in an interleaved thread.
1136
-- It shares everything with the parent thread, so this is DANGEROUS.
1138
-- It returns Nothing if the computation fails
1140
-- It's used for lazily type-checking interface
1141
-- signatures, which is pretty benign
1143
forkM_maybe doc thing_inside
1144
= do { unsafeInterleaveM $
1145
do { traceIf (text "Starting fork {" <+> doc)
1147
updLclEnv (\env -> env { if_loc = if_loc env $$ doc }) $
1150
Right r -> do { traceIf (text "} ending fork" <+> doc)
1154
-- Bleat about errors in the forked thread, if -ddump-if-trace is on
1155
-- Otherwise we silently discard errors. Errors can legitimately
1156
-- happen when compiling interface signatures (see tcInterfaceSigs)
1157
ifDOptM Opt_D_dump_if_trace
1158
(print_errs (hang (text "forkM failed:" <+> doc)
1159
2 (text (show exn))))
1161
; traceIf (text "} ending fork (badly)" <+> doc)
1165
print_errs sdoc = liftIO (printErrs (sdoc defaultErrStyle))
1167
forkM :: SDoc -> IfL a -> IfL a
1168
forkM doc thing_inside
1169
= do { mb_res <- forkM_maybe doc thing_inside
1170
; return (case mb_res of
1171
Nothing -> pgmError "Cannot continue after interface file error"
1172
-- pprPanic "forkM" doc
added
removed
compiler/typecheck/TcRnMonad.lhs
