+++ /dev/null
-\begin{code}
-module TcRnMonad(
- module TcRnMonad,
- module TcRnTypes,
- module IOEnv
- ) where
-
-#include "HsVersions.h"
-
-import TcRnTypes -- Re-export all
-import IOEnv -- Re-export all
-
-#if defined(GHCI) && defined(BREAKPOINT)
-import TypeRep ( Type(..), liftedTypeKind, TyThing(..) )
-import Var ( mkTyVar, mkGlobalId )
-import IdInfo ( GlobalIdDetails(..), vanillaIdInfo )
-import OccName ( mkOccName, tvName )
-import SrcLoc ( noSrcLoc )
-import TysWiredIn ( intTy, stringTy, mkListTy, unitTy )
-import PrelNames ( breakpointJumpName )
-import NameEnv ( mkNameEnv )
-#endif
-
-import HsSyn ( emptyLHsBinds )
-import HscTypes ( HscEnv(..), ModGuts(..), ModIface(..),
- TyThing, TypeEnv, emptyTypeEnv, HscSource(..),
- isHsBoot, ModSummary(..),
- ExternalPackageState(..), HomePackageTable,
- Deprecs(..), FixityEnv, FixItem,
- lookupType, unQualInScope )
-import Module ( Module, unitModuleEnv )
-import RdrName ( GlobalRdrEnv, emptyGlobalRdrEnv,
- LocalRdrEnv, emptyLocalRdrEnv )
-import Name ( Name, isInternalName, mkInternalName, tidyNameOcc, nameOccName, getSrcLoc )
-import Type ( Type )
-import TcType ( tcIsTyVarTy, tcGetTyVar )
-import NameEnv ( extendNameEnvList, nameEnvElts )
-import InstEnv ( emptyInstEnv )
-
-import Var ( setTyVarName )
-import VarSet ( emptyVarSet )
-import VarEnv ( TidyEnv, emptyTidyEnv, extendVarEnv )
-import ErrUtils ( Message, Messages, emptyMessages, errorsFound,
- mkWarnMsg, printErrorsAndWarnings,
- mkLocMessage, mkLongErrMsg )
-import Packages ( mkHomeModules )
-import SrcLoc ( mkGeneralSrcSpan, isGoodSrcSpan, SrcSpan, Located(..) )
-import NameEnv ( emptyNameEnv )
-import NameSet ( NameSet, emptyDUs, emptyNameSet, unionNameSets, addOneToNameSet )
-import OccName ( emptyOccEnv, tidyOccName )
-import Bag ( emptyBag )
-import Outputable
-import UniqSupply ( UniqSupply, mkSplitUniqSupply, uniqFromSupply, splitUniqSupply )
-import Unique ( Unique )
-import DynFlags ( DynFlags(..), DynFlag(..), dopt, dopt_set, GhcMode )
-import StaticFlags ( opt_PprStyle_Debug )
-import Bag ( snocBag, unionBags )
-import Panic ( showException )
-
-import IO ( stderr )
-import DATA_IOREF ( newIORef, readIORef )
-import EXCEPTION ( Exception )
-\end{code}
-
-
-
-%************************************************************************
-%* *
- initTc
-%* *
-%************************************************************************
-
-\begin{code}
-ioToTcRn :: IO r -> TcRn r
-ioToTcRn = ioToIOEnv
-\end{code}
-
-\begin{code}
-initTc :: HscEnv
- -> HscSource
- -> Module
- -> TcM r
- -> IO (Messages, Maybe r)
- -- Nothing => error thrown by the thing inside
- -- (error messages should have been printed already)
-
-initTc hsc_env hsc_src mod do_this
- = do { errs_var <- newIORef (emptyBag, emptyBag) ;
- tvs_var <- newIORef emptyVarSet ;
- type_env_var <- newIORef emptyNameEnv ;
- dfuns_var <- newIORef emptyNameSet ;
- keep_var <- newIORef emptyNameSet ;
- th_var <- newIORef False ;
- dfun_n_var <- newIORef 1 ;
- let {
- gbl_env = TcGblEnv {
- tcg_mod = mod,
- tcg_src = hsc_src,
- tcg_rdr_env = emptyGlobalRdrEnv,
- tcg_fix_env = emptyNameEnv,
- tcg_default = Nothing,
- tcg_type_env = emptyNameEnv,
- tcg_type_env_var = type_env_var,
- tcg_inst_env = emptyInstEnv,
- tcg_inst_uses = dfuns_var,
- tcg_th_used = th_var,
- tcg_exports = emptyNameSet,
- tcg_imports = init_imports,
- tcg_home_mods = home_mods,
- tcg_dus = emptyDUs,
- tcg_rn_imports = Nothing,
- tcg_rn_exports = Nothing,
- tcg_rn_decls = Nothing,
- tcg_binds = emptyLHsBinds,
- tcg_deprecs = NoDeprecs,
- tcg_insts = [],
- tcg_rules = [],
- tcg_fords = [],
- tcg_dfun_n = dfun_n_var,
- tcg_keep = keep_var
- } ;
- lcl_env = TcLclEnv {
- tcl_errs = errs_var,
- tcl_loc = mkGeneralSrcSpan FSLIT("Top level"),
- tcl_ctxt = [],
- tcl_rdr = emptyLocalRdrEnv,
- tcl_th_ctxt = topStage,
- tcl_arrow_ctxt = NoArrowCtxt,
- tcl_env = emptyNameEnv,
- tcl_tyvars = tvs_var,
- tcl_lie = panic "initTc:LIE" -- LIE only valid inside a getLIE
- } ;
- } ;
-
- -- OK, here's the business end!
- maybe_res <- initTcRnIf 'a' hsc_env gbl_env lcl_env $
- do {
-#if defined(GHCI) && defined(BREAKPOINT)
- unique <- newUnique ;
- let { var = mkInternalName unique (mkOccName tvName "a") noSrcLoc;
- tyvar = mkTyVar var liftedTypeKind;
- breakpointJumpType = mkGlobalId
- (VanillaGlobal)
- (breakpointJumpName)
- (FunTy intTy
- (FunTy (mkListTy unitTy)
- (FunTy stringTy
- (ForAllTy tyvar
- (FunTy (TyVarTy tyvar)
- (TyVarTy tyvar))))))
- (vanillaIdInfo);
- new_env = mkNameEnv [(breakpointJumpName,AGlobal (AnId breakpointJumpType))];
- };
- r <- tryM (updLclEnv (\gbl -> gbl{tcl_env=new_env}) do_this)
-#else
- r <- tryM do_this
-#endif
- ; case r of
- Right res -> return (Just res)
- Left _ -> return Nothing } ;
-
- -- Collect any error messages
- msgs <- readIORef errs_var ;
-
- let { dflags = hsc_dflags hsc_env
- ; final_res | errorsFound dflags msgs = Nothing
- | otherwise = maybe_res } ;
-
- return (msgs, final_res)
- }
- where
- home_mods = mkHomeModules (map ms_mod (hsc_mod_graph hsc_env))
- -- A guess at the home modules. This will be correct in
- -- --make and GHCi modes, but in one-shot mode we need to
- -- fix it up after we know the real dependencies of the current
- -- module (see tcRnModule).
- -- Setting it here is necessary for the typechecker entry points
- -- other than tcRnModule: tcRnGetInfo, for example. These are
- -- all called via the GHC module, so hsc_mod_graph will contain
- -- something sensible.
-
- init_imports = emptyImportAvails {imp_env = unitModuleEnv mod emptyNameSet}
- -- Initialise tcg_imports with an empty set of bindings for
- -- this module, so that if we see 'module M' in the export
- -- list, and there are no bindings in M, we don't bleat
- -- "unknown module M".
-
-initTcPrintErrors -- Used from the interactive loop only
- :: HscEnv
- -> Module
- -> TcM r
- -> IO (Maybe r)
-initTcPrintErrors env mod todo = do
- (msgs, res) <- initTc env HsSrcFile mod todo
- printErrorsAndWarnings (hsc_dflags env) msgs
- return res
-
--- mkImpTypeEnv makes the imported symbol table
-mkImpTypeEnv :: ExternalPackageState -> HomePackageTable
- -> Name -> Maybe TyThing
-mkImpTypeEnv pcs hpt = lookup
- where
- pte = eps_PTE pcs
- lookup name | isInternalName name = Nothing
- | otherwise = lookupType hpt pte name
-\end{code}
-
-
-%************************************************************************
-%* *
- Initialisation
-%* *
-%************************************************************************
-
-
-\begin{code}
-initTcRnIf :: Char -- Tag for unique supply
- -> HscEnv
- -> gbl -> lcl
- -> TcRnIf gbl lcl a
- -> IO a
-initTcRnIf uniq_tag hsc_env gbl_env lcl_env thing_inside
- = do { us <- mkSplitUniqSupply uniq_tag ;
- ; us_var <- newIORef us ;
-
- ; let { env = Env { env_top = hsc_env,
- env_us = us_var,
- env_gbl = gbl_env,
- env_lcl = lcl_env } }
-
- ; runIOEnv env thing_inside
- }
-\end{code}
-
-%************************************************************************
-%* *
- Simple accessors
-%* *
-%************************************************************************
-
-\begin{code}
-getTopEnv :: TcRnIf gbl lcl HscEnv
-getTopEnv = do { env <- getEnv; return (env_top env) }
-
-getGblEnv :: TcRnIf gbl lcl gbl
-getGblEnv = do { env <- getEnv; return (env_gbl env) }
-
-updGblEnv :: (gbl -> gbl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
-updGblEnv upd = updEnv (\ env@(Env { env_gbl = gbl }) ->
- env { env_gbl = upd gbl })
-
-setGblEnv :: gbl -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
-setGblEnv gbl_env = updEnv (\ env -> env { env_gbl = gbl_env })
-
-getLclEnv :: TcRnIf gbl lcl lcl
-getLclEnv = do { env <- getEnv; return (env_lcl env) }
-
-updLclEnv :: (lcl -> lcl) -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
-updLclEnv upd = updEnv (\ env@(Env { env_lcl = lcl }) ->
- env { env_lcl = upd lcl })
-
-setLclEnv :: lcl' -> TcRnIf gbl lcl' a -> TcRnIf gbl lcl a
-setLclEnv lcl_env = updEnv (\ env -> env { env_lcl = lcl_env })
-
-getEnvs :: TcRnIf gbl lcl (gbl, lcl)
-getEnvs = do { env <- getEnv; return (env_gbl env, env_lcl env) }
-
-setEnvs :: (gbl', lcl') -> TcRnIf gbl' lcl' a -> TcRnIf gbl lcl a
-setEnvs (gbl_env, lcl_env) = updEnv (\ env -> env { env_gbl = gbl_env, env_lcl = lcl_env })
-\end{code}
-
-
-Command-line flags
-
-\begin{code}
-getDOpts :: TcRnIf gbl lcl DynFlags
-getDOpts = do { env <- getTopEnv; return (hsc_dflags env) }
-
-doptM :: DynFlag -> TcRnIf gbl lcl Bool
-doptM flag = do { dflags <- getDOpts; return (dopt flag dflags) }
-
-setOptM :: DynFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a
-setOptM flag = updEnv (\ env@(Env { env_top = top }) ->
- env { env_top = top { hsc_dflags = dopt_set (hsc_dflags top) flag}} )
-
-ifOptM :: DynFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl () -- Do it flag is true
-ifOptM flag thing_inside = do { b <- doptM flag;
- if b then thing_inside else return () }
-
-getGhcMode :: TcRnIf gbl lcl GhcMode
-getGhcMode = do { env <- getTopEnv; return (ghcMode (hsc_dflags env)) }
-\end{code}
-
-\begin{code}
-getEpsVar :: TcRnIf gbl lcl (TcRef ExternalPackageState)
-getEpsVar = do { env <- getTopEnv; return (hsc_EPS env) }
-
-getEps :: TcRnIf gbl lcl ExternalPackageState
-getEps = do { env <- getTopEnv; readMutVar (hsc_EPS env) }
-
--- Updating the EPS. This should be an atomic operation.
--- Note the delicate 'seq' which forces the EPS before putting it in the
--- variable. Otherwise what happens is that we get
--- write eps_var (....(unsafeRead eps_var)....)
--- and if the .... is strict, that's obviously bottom. By forcing it beforehand
--- we make the unsafeRead happen before we update the variable.
-
-updateEps :: (ExternalPackageState -> (ExternalPackageState, a))
- -> TcRnIf gbl lcl a
-updateEps upd_fn = do { traceIf (text "updating EPS")
- ; eps_var <- getEpsVar
- ; eps <- readMutVar eps_var
- ; let { (eps', val) = upd_fn eps }
- ; seq eps' (writeMutVar eps_var eps')
- ; return val }
-
-updateEps_ :: (ExternalPackageState -> ExternalPackageState)
- -> TcRnIf gbl lcl ()
-updateEps_ upd_fn = do { traceIf (text "updating EPS_")
- ; eps_var <- getEpsVar
- ; eps <- readMutVar eps_var
- ; let { eps' = upd_fn eps }
- ; seq eps' (writeMutVar eps_var eps') }
-
-getHpt :: TcRnIf gbl lcl HomePackageTable
-getHpt = do { env <- getTopEnv; return (hsc_HPT env) }
-
-getEpsAndHpt :: TcRnIf gbl lcl (ExternalPackageState, HomePackageTable)
-getEpsAndHpt = do { env <- getTopEnv; eps <- readMutVar (hsc_EPS env)
- ; return (eps, hsc_HPT env) }
-\end{code}
-
-%************************************************************************
-%* *
- Unique supply
-%* *
-%************************************************************************
-
-\begin{code}
-newUnique :: TcRnIf gbl lcl Unique
-newUnique = do { us <- newUniqueSupply ;
- return (uniqFromSupply us) }
-
-newUniqueSupply :: TcRnIf gbl lcl UniqSupply
-newUniqueSupply
- = do { env <- getEnv ;
- let { u_var = env_us env } ;
- us <- readMutVar u_var ;
- let { (us1, us2) = splitUniqSupply us } ;
- writeMutVar u_var us1 ;
- return us2 }
-
-newLocalName :: Name -> TcRnIf gbl lcl Name
-newLocalName name -- Make a clone
- = newUnique `thenM` \ uniq ->
- returnM (mkInternalName uniq (nameOccName name) (getSrcLoc name))
-\end{code}
-
-
-%************************************************************************
-%* *
- Debugging
-%* *
-%************************************************************************
-
-\begin{code}
-traceTc, traceRn :: SDoc -> TcRn ()
-traceRn = traceOptTcRn Opt_D_dump_rn_trace
-traceTc = traceOptTcRn Opt_D_dump_tc_trace
-traceSplice = traceOptTcRn Opt_D_dump_splices
-
-
-traceIf :: SDoc -> TcRnIf m n ()
-traceIf = traceOptIf Opt_D_dump_if_trace
-traceHiDiffs = traceOptIf Opt_D_dump_hi_diffs
-
-
-traceOptIf :: DynFlag -> SDoc -> TcRnIf m n () -- No RdrEnv available, so qualify everything
-traceOptIf flag doc = ifOptM flag $
- ioToIOEnv (printForUser stderr alwaysQualify doc)
-
-traceOptTcRn :: DynFlag -> SDoc -> TcRn ()
-traceOptTcRn flag doc = ifOptM flag $ do
- { ctxt <- getErrCtxt
- ; loc <- getSrcSpanM
- ; env0 <- tcInitTidyEnv
- ; ctxt_msgs <- do_ctxt env0 ctxt
- ; let real_doc = mkLocMessage loc (vcat (doc : ctxt_to_use ctxt_msgs))
- ; dumpTcRn real_doc }
-
-dumpTcRn :: SDoc -> TcRn ()
-dumpTcRn doc = do { rdr_env <- getGlobalRdrEnv ;
- ioToTcRn (printForUser stderr (unQualInScope rdr_env) doc) }
-
-dumpOptTcRn :: DynFlag -> SDoc -> TcRn ()
-dumpOptTcRn flag doc = ifOptM flag (dumpTcRn doc)
-\end{code}
-
-
-%************************************************************************
-%* *
- Typechecker global environment
-%* *
-%************************************************************************
-
-\begin{code}
-getModule :: TcRn Module
-getModule = do { env <- getGblEnv; return (tcg_mod env) }
-
-setModule :: Module -> TcRn a -> TcRn a
-setModule mod thing_inside = updGblEnv (\env -> env { tcg_mod = mod }) thing_inside
-
-tcIsHsBoot :: TcRn Bool
-tcIsHsBoot = do { env <- getGblEnv; return (isHsBoot (tcg_src env)) }
-
-getGlobalRdrEnv :: TcRn GlobalRdrEnv
-getGlobalRdrEnv = do { env <- getGblEnv; return (tcg_rdr_env env) }
-
-getImports :: TcRn ImportAvails
-getImports = do { env <- getGblEnv; return (tcg_imports env) }
-
-getFixityEnv :: TcRn FixityEnv
-getFixityEnv = do { env <- getGblEnv; return (tcg_fix_env env) }
-
-extendFixityEnv :: [(Name,FixItem)] -> RnM a -> RnM a
-extendFixityEnv new_bit
- = updGblEnv (\env@(TcGblEnv { tcg_fix_env = old_fix_env }) ->
- env {tcg_fix_env = extendNameEnvList old_fix_env new_bit})
-
-getDefaultTys :: TcRn (Maybe [Type])
-getDefaultTys = do { env <- getGblEnv; return (tcg_default env) }
-\end{code}
-
-%************************************************************************
-%* *
- Error management
-%* *
-%************************************************************************
-
-\begin{code}
-getSrcSpanM :: TcRn SrcSpan
- -- Avoid clash with Name.getSrcLoc
-getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
-
-setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
-setSrcSpan loc thing_inside
- | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
- | otherwise = thing_inside -- Don't overwrite useful info with useless
-
-addLocM :: (a -> TcM b) -> Located a -> TcM b
-addLocM fn (L loc a) = setSrcSpan loc $ fn a
-
-wrapLocM :: (a -> TcM b) -> Located a -> TcM (Located b)
-wrapLocM fn (L loc a) = setSrcSpan loc $ do b <- fn a; return (L loc b)
-
-wrapLocFstM :: (a -> TcM (b,c)) -> Located a -> TcM (Located b, c)
-wrapLocFstM fn (L loc a) =
- setSrcSpan loc $ do
- (b,c) <- fn a
- return (L loc b, c)
-
-wrapLocSndM :: (a -> TcM (b,c)) -> Located a -> TcM (b, Located c)
-wrapLocSndM fn (L loc a) =
- setSrcSpan loc $ do
- (b,c) <- fn a
- return (b, L loc c)
-\end{code}
-
-
-\begin{code}
-getErrsVar :: TcRn (TcRef Messages)
-getErrsVar = do { env <- getLclEnv; return (tcl_errs env) }
-
-setErrsVar :: TcRef Messages -> TcRn a -> TcRn a
-setErrsVar v = updLclEnv (\ env -> env { tcl_errs = v })
-
-addErr :: Message -> TcRn ()
-addErr msg = do { loc <- getSrcSpanM ; addErrAt loc msg }
-
-addLocErr :: Located e -> (e -> Message) -> TcRn ()
-addLocErr (L loc e) fn = addErrAt loc (fn e)
-
-addErrAt :: SrcSpan -> Message -> TcRn ()
-addErrAt loc msg = addLongErrAt loc msg empty
-
-addLongErrAt :: SrcSpan -> Message -> Message -> TcRn ()
-addLongErrAt loc msg extra
- = do { traceTc (ptext SLIT("Adding error:") <+> (mkLocMessage loc (msg $$ extra))) ;
- errs_var <- getErrsVar ;
- rdr_env <- getGlobalRdrEnv ;
- let { err = mkLongErrMsg loc (unQualInScope rdr_env) msg extra } ;
- (warns, errs) <- readMutVar errs_var ;
- writeMutVar errs_var (warns, errs `snocBag` err) }
-
-addErrs :: [(SrcSpan,Message)] -> TcRn ()
-addErrs msgs = mappM_ add msgs
- where
- add (loc,msg) = addErrAt loc msg
-
-addReport :: Message -> TcRn ()
-addReport msg = do loc <- getSrcSpanM; addReportAt loc msg
-
-addReportAt :: SrcSpan -> Message -> TcRn ()
-addReportAt loc msg
- = do { errs_var <- getErrsVar ;
- rdr_env <- getGlobalRdrEnv ;
- let { warn = mkWarnMsg loc (unQualInScope rdr_env) msg } ;
- (warns, errs) <- readMutVar errs_var ;
- writeMutVar errs_var (warns `snocBag` warn, errs) }
-
-addWarn :: Message -> TcRn ()
-addWarn msg = addReport (ptext SLIT("Warning:") <+> msg)
-
-addWarnAt :: SrcSpan -> Message -> TcRn ()
-addWarnAt loc msg = addReportAt loc (ptext SLIT("Warning:") <+> msg)
-
-addLocWarn :: Located e -> (e -> Message) -> TcRn ()
-addLocWarn (L loc e) fn = addReportAt loc (fn e)
-
-checkErr :: Bool -> Message -> TcRn ()
--- Add the error if the bool is False
-checkErr ok msg = checkM ok (addErr msg)
-
-warnIf :: Bool -> Message -> TcRn ()
-warnIf True msg = addWarn msg
-warnIf False msg = return ()
-
-addMessages :: Messages -> TcRn ()
-addMessages (m_warns, m_errs)
- = do { errs_var <- getErrsVar ;
- (warns, errs) <- readMutVar errs_var ;
- writeMutVar errs_var (warns `unionBags` m_warns,
- errs `unionBags` m_errs) }
-
-discardWarnings :: TcRn a -> TcRn a
--- Ignore warnings inside the thing inside;
--- used to ignore-unused-variable warnings inside derived code
--- With -dppr-debug, the effects is switched off, so you can still see
--- what warnings derived code would give
-discardWarnings thing_inside
- | opt_PprStyle_Debug = thing_inside
- | otherwise
- = do { errs_var <- newMutVar emptyMessages
- ; result <- setErrsVar errs_var thing_inside
- ; (_warns, errs) <- readMutVar errs_var
- ; addMessages (emptyBag, errs)
- ; return result }
-\end{code}
-
-
-\begin{code}
-try_m :: TcRn r -> TcRn (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 "tryTc/recoverM recovering from" <+> text (showException exn)
-
------------------------
-recoverM :: TcRn r -- Recovery action; do this if the main one fails
- -> TcRn r -- Main action: do this first
- -> TcRn r
--- Errors in 'thing' are retained
-recoverM recover thing
- = do { mb_res <- try_m thing ;
- case mb_res of
- Left exn -> recover
- Right res -> returnM res }
-
------------------------
-tryTc :: TcRn a -> TcRn (Messages, Maybe a)
--- (tryTc m) executes m, and returns
--- Just r, if m succeeds (returning r)
--- Nothing, if m fails
--- It also returns all the errors and warnings accumulated by m
--- It always succeeds (never raises an exception)
-tryTc m
- = do { errs_var <- newMutVar emptyMessages ;
- res <- try_m (setErrsVar errs_var m) ;
- msgs <- readMutVar errs_var ;
- return (msgs, case res of
- Left exn -> Nothing
- Right val -> Just val)
- -- The exception is always the IOEnv built-in
- -- in exception; see IOEnv.failM
- }
-
------------------------
-tryTcErrs :: TcRn a -> TcRn (Messages, Maybe a)
--- Run the thing, returning
--- Just r, if m succceeds with no error messages
--- Nothing, if m fails, or if it succeeds but has error messages
--- Either way, the messages are returned; even in the Just case
--- there might be warnings
-tryTcErrs thing
- = do { (msgs, res) <- tryTc thing
- ; dflags <- getDOpts
- ; let errs_found = errorsFound dflags msgs
- ; return (msgs, case res of
- Nothing -> Nothing
- Just val | errs_found -> Nothing
- | otherwise -> Just val)
- }
-
------------------------
-tryTcLIE :: TcM a -> TcM (Messages, Maybe a)
--- Just like tryTcErrs, except that it ensures that the LIE
--- for the thing is propagated only if there are no errors
--- Hence it's restricted to the type-check monad
-tryTcLIE thing_inside
- = do { ((msgs, mb_res), lie) <- getLIE (tryTcErrs thing_inside) ;
- ; case mb_res of
- Nothing -> return (msgs, Nothing)
- Just val -> do { extendLIEs lie; return (msgs, Just val) }
- }
-
------------------------
-tryTcLIE_ :: TcM r -> TcM r -> TcM r
--- (tryTcLIE_ r m) tries m;
--- if m succeeds with no error messages, it's the answer
--- otherwise tryTcLIE_ drops everything from m and tries r instead.
-tryTcLIE_ recover main
- = do { (msgs, mb_res) <- tryTcLIE main
- ; case mb_res of
- Just val -> do { addMessages msgs -- There might be warnings
- ; return val }
- Nothing -> recover -- Discard all msgs
- }
-
------------------------
-checkNoErrs :: TcM r -> TcM r
--- (checkNoErrs m) succeeds iff m succeeds and generates no errors
--- If m fails then (checkNoErrsTc m) fails.
--- If m succeeds, it checks whether m generated any errors messages
--- (it might have recovered internally)
--- If so, it fails too.
--- Regardless, any errors generated by m are propagated to the enclosing context.
-checkNoErrs main
- = do { (msgs, mb_res) <- tryTcLIE main
- ; addMessages msgs
- ; case mb_res of
- Nothing -> failM
- Just val -> return val
- }
-
-ifErrsM :: TcRn r -> TcRn r -> TcRn r
--- ifErrsM bale_out main
--- does 'bale_out' if there are errors in errors collection
--- otherwise does 'main'
-ifErrsM bale_out normal
- = do { errs_var <- getErrsVar ;
- msgs <- readMutVar errs_var ;
- dflags <- getDOpts ;
- if errorsFound dflags msgs then
- bale_out
- else
- normal }
-
-failIfErrsM :: TcRn ()
--- Useful to avoid error cascades
-failIfErrsM = ifErrsM failM (return ())
-\end{code}
-
-
-%************************************************************************
-%* *
- Context management and error message generation
- for the type checker
-%* *
-%************************************************************************
-
-\begin{code}
-getErrCtxt :: TcM ErrCtxt
-getErrCtxt = do { env <- getLclEnv; return (tcl_ctxt env) }
-
-setErrCtxt :: ErrCtxt -> TcM a -> TcM a
-setErrCtxt ctxt = updLclEnv (\ env -> env { tcl_ctxt = ctxt })
-
-addErrCtxt :: Message -> TcM a -> TcM a
-addErrCtxt msg = addErrCtxtM (\env -> returnM (env, msg))
-
-addErrCtxtM :: (TidyEnv -> TcM (TidyEnv, Message)) -> TcM a -> TcM a
-addErrCtxtM msg = updCtxt (\ msgs -> msg : msgs)
-
--- Helper function for the above
-updCtxt :: (ErrCtxt -> ErrCtxt) -> TcM a -> TcM a
-updCtxt upd = updLclEnv (\ env@(TcLclEnv { tcl_ctxt = ctxt }) ->
- env { tcl_ctxt = upd ctxt })
-
--- Conditionally add an error context
-maybeAddErrCtxt :: Maybe Message -> TcM a -> TcM a
-maybeAddErrCtxt (Just msg) thing_inside = addErrCtxt msg thing_inside
-maybeAddErrCtxt Nothing thing_inside = thing_inside
-
-popErrCtxt :: TcM a -> TcM a
-popErrCtxt = updCtxt (\ msgs -> case msgs of { [] -> []; (m:ms) -> ms })
-
-getInstLoc :: InstOrigin -> TcM InstLoc
-getInstLoc origin
- = do { loc <- getSrcSpanM ; env <- getLclEnv ;
- return (InstLoc origin loc (tcl_ctxt env)) }
-
-addInstCtxt :: InstLoc -> TcM a -> TcM a
--- Add the SrcSpan and context from the first Inst in the list
--- (they all have similar locations)
-addInstCtxt (InstLoc _ src_loc ctxt) thing_inside
- = setSrcSpan src_loc (updCtxt (\ old_ctxt -> ctxt) thing_inside)
-\end{code}
-
- The addErrTc functions add an error message, but do not cause failure.
- The 'M' variants pass a TidyEnv that has already been used to
- tidy up the message; we then use it to tidy the context messages
-
-\begin{code}
-addErrTc :: Message -> TcM ()
-addErrTc err_msg = do { env0 <- tcInitTidyEnv
- ; addErrTcM (env0, err_msg) }
-
-addErrsTc :: [Message] -> TcM ()
-addErrsTc err_msgs = mappM_ addErrTc err_msgs
-
-addErrTcM :: (TidyEnv, Message) -> TcM ()
-addErrTcM (tidy_env, err_msg)
- = do { ctxt <- getErrCtxt ;
- loc <- getSrcSpanM ;
- add_err_tcm tidy_env err_msg loc ctxt }
-\end{code}
-
-The failWith functions add an error message and cause failure
-
-\begin{code}
-failWithTc :: Message -> TcM a -- Add an error message and fail
-failWithTc err_msg
- = addErrTc err_msg >> failM
-
-failWithTcM :: (TidyEnv, Message) -> TcM a -- Add an error message and fail
-failWithTcM local_and_msg
- = addErrTcM local_and_msg >> failM
-
-checkTc :: Bool -> Message -> TcM () -- Check that the boolean is true
-checkTc True err = returnM ()
-checkTc False err = failWithTc err
-\end{code}
-
- Warnings have no 'M' variant, nor failure
-
-\begin{code}
-addWarnTc :: Message -> TcM ()
-addWarnTc msg
- = do { ctxt <- getErrCtxt ;
- env0 <- tcInitTidyEnv ;
- ctxt_msgs <- do_ctxt env0 ctxt ;
- addWarn (vcat (msg : ctxt_to_use ctxt_msgs)) }
-
-warnTc :: Bool -> Message -> TcM ()
-warnTc warn_if_true warn_msg
- | warn_if_true = addWarnTc warn_msg
- | otherwise = return ()
-\end{code}
-
------------------------------------
- Tidying
-
-We initialise the "tidy-env", used for tidying types before printing,
-by building a reverse map from the in-scope type variables to the
-OccName that the programmer originally used for them
-
-\begin{code}
-tcInitTidyEnv :: TcM TidyEnv
-tcInitTidyEnv
- = do { lcl_env <- getLclEnv
- ; let nm_tv_prs = [ (name, tcGetTyVar "tcInitTidyEnv" ty)
- | ATyVar name ty <- nameEnvElts (tcl_env lcl_env)
- , tcIsTyVarTy ty ]
- ; return (foldl add emptyTidyEnv nm_tv_prs) }
- where
- add (env,subst) (name, tyvar)
- = case tidyOccName env (nameOccName name) of
- (env', occ') -> (env', extendVarEnv subst tyvar tyvar')
- where
- tyvar' = setTyVarName tyvar name'
- name' = tidyNameOcc name occ'
-\end{code}
-
------------------------------------
- Other helper functions
-
-\begin{code}
-add_err_tcm tidy_env err_msg loc ctxt
- = do { ctxt_msgs <- do_ctxt tidy_env ctxt ;
- addLongErrAt loc err_msg (vcat (ctxt_to_use ctxt_msgs)) }
-
-do_ctxt tidy_env []
- = return []
-do_ctxt tidy_env (c:cs)
- = do { (tidy_env', m) <- c tidy_env ;
- ms <- do_ctxt tidy_env' cs ;
- return (m:ms) }
-
-ctxt_to_use ctxt | opt_PprStyle_Debug = ctxt
- | otherwise = take 3 ctxt
-\end{code}
-
-debugTc is useful for monadic debugging code
-
-\begin{code}
-debugTc :: TcM () -> TcM ()
-#ifdef DEBUG
-debugTc thing = thing
-#else
-debugTc thing = return ()
-#endif
-\end{code}
-
- %************************************************************************
-%* *
- Type constraints (the so-called LIE)
-%* *
-%************************************************************************
-
-\begin{code}
-nextDFunIndex :: TcM Int -- Get the next dfun index
-nextDFunIndex = do { env <- getGblEnv
- ; let dfun_n_var = tcg_dfun_n env
- ; n <- readMutVar dfun_n_var
- ; writeMutVar dfun_n_var (n+1)
- ; return n }
-
-getLIEVar :: TcM (TcRef LIE)
-getLIEVar = do { env <- getLclEnv; return (tcl_lie env) }
-
-setLIEVar :: TcRef LIE -> TcM a -> TcM a
-setLIEVar lie_var = updLclEnv (\ env -> env { tcl_lie = lie_var })
-
-getLIE :: TcM a -> TcM (a, [Inst])
--- (getLIE m) runs m, and returns the type constraints it generates
-getLIE thing_inside
- = do { lie_var <- newMutVar emptyLIE ;
- res <- updLclEnv (\ env -> env { tcl_lie = lie_var })
- thing_inside ;
- lie <- readMutVar lie_var ;
- return (res, lieToList lie) }
-
-extendLIE :: Inst -> TcM ()
-extendLIE inst
- = do { lie_var <- getLIEVar ;
- lie <- readMutVar lie_var ;
- writeMutVar lie_var (inst `consLIE` lie) }
-
-extendLIEs :: [Inst] -> TcM ()
-extendLIEs []
- = returnM ()
-extendLIEs insts
- = do { lie_var <- getLIEVar ;
- lie <- readMutVar lie_var ;
- writeMutVar lie_var (mkLIE insts `plusLIE` lie) }
-\end{code}
-
-\begin{code}
-setLclTypeEnv :: TcLclEnv -> TcM a -> TcM a
--- Set the local type envt, but do *not* disturb other fields,
--- notably the lie_var
-setLclTypeEnv lcl_env thing_inside
- = updLclEnv upd thing_inside
- where
- upd env = env { tcl_env = tcl_env lcl_env,
- tcl_tyvars = tcl_tyvars lcl_env }
-\end{code}
-
-
-%************************************************************************
-%* *
- Template Haskell context
-%* *
-%************************************************************************
-
-\begin{code}
-recordThUse :: TcM ()
-recordThUse = do { env <- getGblEnv; writeMutVar (tcg_th_used env) True }
-
-keepAliveTc :: Name -> TcM () -- Record the name in the keep-alive set
-keepAliveTc n = do { env <- getGblEnv;
- ; updMutVar (tcg_keep env) (`addOneToNameSet` n) }
-
-keepAliveSetTc :: NameSet -> TcM () -- Record the name in the keep-alive set
-keepAliveSetTc ns = do { env <- getGblEnv;
- ; updMutVar (tcg_keep env) (`unionNameSets` ns) }
-
-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}
-
-
-%************************************************************************
-%* *
- Stuff for the renamer's local env
-%* *
-%************************************************************************
-
-\begin{code}
-getLocalRdrEnv :: RnM LocalRdrEnv
-getLocalRdrEnv = do { env <- getLclEnv; return (tcl_rdr env) }
-
-setLocalRdrEnv :: LocalRdrEnv -> RnM a -> RnM a
-setLocalRdrEnv rdr_env thing_inside
- = updLclEnv (\env -> env {tcl_rdr = rdr_env}) thing_inside
-\end{code}
-
-
-%************************************************************************
-%* *
- Stuff for interface decls
-%* *
-%************************************************************************
-
-\begin{code}
-mkIfLclEnv :: Module -> SDoc -> IfLclEnv
-mkIfLclEnv mod loc = IfLclEnv { if_mod = mod,
- if_loc = loc,
- if_tv_env = emptyOccEnv,
- if_id_env = emptyOccEnv }
-
-initIfaceTcRn :: IfG a -> TcRn a
-initIfaceTcRn thing_inside
- = do { tcg_env <- getGblEnv
- ; let { if_env = IfGblEnv { if_rec_types = Just (tcg_mod tcg_env, get_type_env) }
- ; get_type_env = readMutVar (tcg_type_env_var tcg_env) }
- ; setEnvs (if_env, ()) thing_inside }
-
-initIfaceExtCore :: IfL a -> TcRn a
-initIfaceExtCore thing_inside
- = do { tcg_env <- getGblEnv
- ; let { mod = tcg_mod tcg_env
- ; doc = ptext SLIT("External Core file for") <+> quotes (ppr mod)
- ; if_env = IfGblEnv {
- if_rec_types = Just (mod, return (tcg_type_env tcg_env)) }
- ; if_lenv = mkIfLclEnv mod doc
- }
- ; setEnvs (if_env, if_lenv) thing_inside }
-
-initIfaceCheck :: HscEnv -> IfG a -> IO a
--- Used when checking the up-to-date-ness of the old Iface
--- Initialise the environment with no useful info at all
-initIfaceCheck hsc_env do_this
- = do { let gbl_env = IfGblEnv { if_rec_types = Nothing }
- ; initTcRnIf 'i' hsc_env gbl_env () do_this
- }
-
-initIfaceTc :: ModIface
- -> (TcRef TypeEnv -> IfL a) -> TcRnIf gbl lcl a
--- Used when type-checking checking an up-to-date interface file
--- No type envt from the current module, but we do know the module dependencies
-initIfaceTc iface do_this
- = do { tc_env_var <- newMutVar emptyTypeEnv
- ; let { gbl_env = IfGblEnv { if_rec_types = Just (mod, readMutVar tc_env_var) } ;
- ; if_lenv = mkIfLclEnv mod doc
- }
- ; setEnvs (gbl_env, if_lenv) (do_this tc_env_var)
- }
- where
- mod = mi_module iface
- doc = ptext SLIT("The interface for") <+> quotes (ppr mod)
-
-initIfaceRules :: HscEnv -> ModGuts -> IfG a -> IO a
--- Used when sucking in new Rules in SimplCore
--- We have available the type envt of the module being compiled, and we must use it
-initIfaceRules hsc_env guts do_this
- = do { let {
- type_info = (mg_module guts, return (mg_types guts))
- ; gbl_env = IfGblEnv { if_rec_types = Just type_info } ;
- }
-
- -- Run the thing; any exceptions just bubble out from here
- ; initTcRnIf 'i' hsc_env gbl_env () do_this
- }
-
-initIfaceLcl :: Module -> SDoc -> IfL a -> IfM lcl a
-initIfaceLcl mod loc_doc thing_inside
- = setLclEnv (mkIfLclEnv mod loc_doc) thing_inside
-
-getIfModule :: IfL Module
-getIfModule = do { env <- getLclEnv; return (if_mod env) }
-
---------------------
-failIfM :: Message -> IfL a
--- The Iface monad doesn't have a place to accumulate errors, so we
--- just fall over fast if one happens; it "shouldnt happen".
--- We use IfL here so that we can get context info out of the local env
-failIfM msg
- = do { env <- getLclEnv
- ; let full_msg = (if_loc env <> colon) $$ nest 2 msg
- ; ioToIOEnv (printErrs (full_msg defaultErrStyle))
- ; failM }
-
---------------------
-forkM_maybe :: SDoc -> IfL a -> IfL (Maybe a)
--- Run thing_inside in an interleaved thread.
--- It shares everything with the parent thread, so this is DANGEROUS.
---
--- It returns Nothing if the computation fails
---
--- It's used for lazily type-checking interface
--- signatures, which is pretty benign
-
-forkM_maybe doc thing_inside
- = do { unsafeInterleaveM $
- do { traceIf (text "Starting fork {" <+> doc)
- ; mb_res <- tryM thing_inside ;
- case mb_res of
- Right r -> do { traceIf (text "} ending fork" <+> doc)
- ; return (Just r) }
- Left exn -> do {
-
- -- Bleat about errors in the forked thread, if -ddump-if-trace is on
- -- Otherwise we silently discard errors. Errors can legitimately
- -- happen when compiling interface signatures (see tcInterfaceSigs)
- ifOptM Opt_D_dump_if_trace
- (print_errs (hang (text "forkM failed:" <+> doc)
- 4 (text (show exn))))
-
- ; traceIf (text "} ending fork (badly)" <+> doc)
- ; return Nothing }
- }}
- where
- print_errs sdoc = ioToIOEnv (printErrs (sdoc defaultErrStyle))
-
-forkM :: SDoc -> IfL a -> IfL a
-forkM doc thing_inside
- = do { mb_res <- forkM_maybe doc thing_inside
- ; return (case mb_res of
- Nothing -> pgmError "Cannot continue after interface file error"
- -- pprPanic "forkM" doc
- Just r -> r) }
-\end{code}
-
-
projects / ghc-hetmet.git / blobdiff