% % (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[TcMovectle]{Typechecking a whole module} \begin{code} {-# OPTIONS -fno-warn-tabs #-} -- The above warning supression flag is a temporary kludge. -- While working on this module you are encouraged to remove it and -- detab the module (please do the detabbing in a separate patch). See -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces -- for details module TcRnDriver ( #ifdef GHCI tcRnStmt, tcRnExpr, tcRnType, tcRnImportDecls, tcRnLookupRdrName, getModuleInterface, tcRnDeclsi, #endif tcRnLookupName, tcRnGetInfo, tcRnModule, tcTopSrcDecls, tcRnExtCore ) where #ifdef GHCI import {-# SOURCE #-} TcSplice ( tcSpliceDecls ) #endif import DynFlags import StaticFlags import HsSyn import PrelNames import RdrName import TcHsSyn import TcExpr import TcRnMonad import TcEvidence import Coercion( pprCoAxiom ) import FamInst import InstEnv import FamInstEnv import TcAnnotations import TcBinds import HeaderInfo ( mkPrelImports ) import TcType ( tidyTopType ) import TcDefaults import TcEnv import TcRules import TcForeign import TcInstDcls import TcIface import TcMType import MkIface import IfaceSyn import TcSimplify import TcTyClsDecls import LoadIface import RnNames import RnEnv import RnSource import PprCore import CoreSyn import ErrUtils import Id import VarEnv import Var import Module import UniqFM import Name import NameEnv import NameSet import Avail import TyCon import SrcLoc import HscTypes import ListSetOps import Outputable import DataCon import Type import Class import TcType ( orphNamesOfDFunHead ) import Inst ( tcGetInstEnvs ) import Data.List ( sortBy ) import Data.IORef ( readIORef ) #ifdef GHCI import TcType ( isUnitTy, isTauTy ) import TcHsType import TcMatches import RnTypes import RnExpr import MkId import BasicTypes import TidyPgm ( globaliseAndTidyId ) import TysWiredIn ( unitTy, mkListTy ) #endif import FastString import Maybes import Util import Bag import Control.Monad #include "HsVersions.h" \end{code} %************************************************************************ %* * Typecheck and rename a module %* * %************************************************************************ \begin{code} -- | Top level entry point for typechecker and renamer tcRnModule :: HscEnv -> HscSource -> Bool -- True <=> save renamed syntax -> HsParsedModule -> IO (Messages, Maybe TcGblEnv) tcRnModule hsc_env hsc_src save_rn_syntax HsParsedModule { hpm_module = (L loc (HsModule maybe_mod export_ies import_decls local_decls mod_deprec maybe_doc_hdr)), hpm_src_files = src_files } = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ; let { this_pkg = thisPackage (hsc_dflags hsc_env) ; (this_mod, prel_imp_loc) = case maybe_mod of Nothing -- 'module M where' is omitted -> (mAIN, srcLocSpan (srcSpanStart loc)) Just (L mod_loc mod) -- The normal case -> (mkModule this_pkg mod, mod_loc) } ; initTc hsc_env hsc_src save_rn_syntax this_mod $ setSrcSpan loc $ do { -- Deal with imports; first add implicit prelude implicit_prelude <- xoptM Opt_ImplicitPrelude; let { prel_imports = mkPrelImports (moduleName this_mod) prel_imp_loc implicit_prelude import_decls } ; ifWOptM Opt_WarnImplicitPrelude $ when (notNull prel_imports) $ addWarn (implicitPreludeWarn) ; tcg_env <- {-# SCC "tcRnImports" #-} tcRnImports hsc_env this_mod (prel_imports ++ import_decls) ; setGblEnv tcg_env $ do { -- Load the hi-boot interface for this module, if any -- We do this now so that the boot_names can be passed -- to tcTyAndClassDecls, because the boot_names are -- automatically considered to be loop breakers -- -- Do this *after* tcRnImports, so that we know whether -- a module that we import imports us; and hence whether to -- look for a hi-boot file boot_iface <- tcHiBootIface hsc_src this_mod ; -- Rename and type check the declarations traceRn (text "rn1a") ; tcg_env <- if isHsBoot hsc_src then tcRnHsBootDecls local_decls else {-# SCC "tcRnSrcDecls" #-} tcRnSrcDecls boot_iface local_decls ; setGblEnv tcg_env $ do { -- Report the use of any deprecated things -- We do this *before* processsing the export list so -- that we don't bleat about re-exporting a deprecated -- thing (especially via 'module Foo' export item) -- That is, only uses in the *body* of the module are complained about traceRn (text "rn3") ; failIfErrsM ; -- finishWarnings crashes sometimes -- as a result of typechecker repairs (e.g. unboundNames) tcg_env <- finishWarnings (hsc_dflags hsc_env) mod_deprec tcg_env ; -- Process the export list traceRn (text "rn4a: before exports"); tcg_env <- rnExports (isJust maybe_mod) export_ies tcg_env ; traceRn (text "rn4b: after exportss") ; -- Check that main is exported (must be after rnExports) checkMainExported tcg_env ; -- Compare the hi-boot iface (if any) with the real thing -- Must be done after processing the exports tcg_env <- checkHiBootIface tcg_env boot_iface ; -- The new type env is already available to stuff slurped from -- interface files, via TcEnv.updateGlobalTypeEnv -- It's important that this includes the stuff in checkHiBootIface, -- because the latter might add new bindings for boot_dfuns, -- which may be mentioned in imported unfoldings -- Don't need to rename the Haddock documentation, -- it's not parsed by GHC anymore. tcg_env <- return (tcg_env { tcg_doc_hdr = maybe_doc_hdr }) ; -- Report unused names reportUnusedNames export_ies tcg_env ; -- add extra source files to tcg_dependent_files addDependentFiles src_files ; -- Dump output and return tcDump tcg_env ; return tcg_env }}}} implicitPreludeWarn :: SDoc implicitPreludeWarn = ptext (sLit "Module `Prelude' implicitly imported") \end{code} %************************************************************************ %* * Import declarations %* * %************************************************************************ \begin{code} tcRnImports :: HscEnv -> Module -> [LImportDecl RdrName] -> TcM TcGblEnv tcRnImports hsc_env this_mod import_decls = do { (rn_imports, rdr_env, imports,hpc_info) <- rnImports import_decls ; ; let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface) -- Make sure we record the dependencies from the DynFlags in the EPS or we -- end up hitting the sanity check in LoadIface.loadInterface that -- checks for unknown home-package modules being loaded. We put -- these dependencies on the left so their (non-source) imports -- take precedence over the (possibly-source) imports on the right. -- We don't add them to any other field (e.g. the imp_dep_mods of -- imports) because we don't want to load their instances etc. ; dep_mods = listToUFM [(mod_nm, (mod_nm, False)) | mod_nm <- dynFlagDependencies (hsc_dflags hsc_env)] `plusUFM` imp_dep_mods imports -- We want instance declarations from all home-package -- modules below this one, including boot modules, except -- ourselves. The 'except ourselves' is so that we don't -- get the instances from this module's hs-boot file ; want_instances :: ModuleName -> Bool ; want_instances mod = mod `elemUFM` dep_mods && mod /= moduleName this_mod ; (home_insts, home_fam_insts) = hptInstances hsc_env want_instances } ; -- Record boot-file info in the EPS, so that it's -- visible to loadHiBootInterface in tcRnSrcDecls, -- and any other incrementally-performed imports ; updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ; -- Update the gbl env ; updGblEnv ( \ gbl -> gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env, tcg_imports = tcg_imports gbl `plusImportAvails` imports, tcg_rn_imports = rn_imports, tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts, tcg_fam_inst_env = extendFamInstEnvList (tcg_fam_inst_env gbl) home_fam_insts, tcg_hpc = hpc_info }) $ do { ; traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) -- Fail if there are any errors so far -- The error printing (if needed) takes advantage -- of the tcg_env we have now set -- ; traceIf (text "rdr_env: " <+> ppr rdr_env) ; failIfErrsM -- Load any orphan-module and family instance-module -- interfaces, so that their rules and instance decls will be -- found. ; loadModuleInterfaces (ptext (sLit "Loading orphan modules")) (imp_orphs imports) -- Check type-family consistency ; traceRn (text "rn1: checking family instance consistency") ; let { dir_imp_mods = moduleEnvKeys . imp_mods $ imports } ; checkFamInstConsistency (imp_finsts imports) dir_imp_mods ; ; getGblEnv } } \end{code} %************************************************************************ %* * Type-checking external-core modules %* * %************************************************************************ \begin{code} tcRnExtCore :: HscEnv -> HsExtCore RdrName -> IO (Messages, Maybe ModGuts) -- Nothing => some error occurred tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds) -- The decls are IfaceDecls; all names are original names = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ; initTc hsc_env ExtCoreFile False this_mod $ do { let { ldecls = map noLoc decls } ; -- Bring the type and class decls into scope -- ToDo: check that this doesn't need to extract the val binds. -- It seems that only the type and class decls need to be in scope below because -- (a) tcTyAndClassDecls doesn't need the val binds, and -- (b) tcExtCoreBindings doesn't need anything -- (in fact, it might not even need to be in the scope of -- this tcg_env at all) (tc_envs, _bndrs) <- getLocalNonValBinders emptyFsEnv {- no fixity decls -} (mkFakeGroup ldecls) ; setEnvs tc_envs $ do { (rn_decls, _fvs) <- checkNoErrs $ rnTyClDecls [] [ldecls] ; -- The empty list is for extra dependencies coming from .hs-boot files -- See Note [Extra dependencies from .hs-boot files] in RnSource -- Dump trace of renaming part rnDump (ppr rn_decls) ; -- Typecheck them all together so that -- any mutually recursive types are done right -- Just discard the auxiliary bindings; they are generated -- only for Haskell source code, and should already be in Core tcg_env <- tcTyAndClassDecls emptyModDetails rn_decls ; safe_mode <- liftIO $ finalSafeMode (hsc_dflags hsc_env) tcg_env ; dep_files <- liftIO $ readIORef (tcg_dependent_files tcg_env) ; setGblEnv tcg_env $ do { -- Make the new type env available to stuff slurped from interface files -- Now the core bindings core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ; -- Wrap up let { bndrs = bindersOfBinds core_binds ; my_exports = map (Avail . idName) bndrs ; -- ToDo: export the data types also? mod_guts = ModGuts { mg_module = this_mod, mg_boot = False, mg_used_names = emptyNameSet, -- ToDo: compute usage mg_used_th = False, mg_dir_imps = emptyModuleEnv, -- ?? mg_deps = noDependencies, -- ?? mg_exports = my_exports, mg_tcs = tcg_tcs tcg_env, mg_insts = tcg_insts tcg_env, mg_fam_insts = tcg_fam_insts tcg_env, mg_inst_env = tcg_inst_env tcg_env, mg_fam_inst_env = tcg_fam_inst_env tcg_env, mg_rules = [], mg_vect_decls = [], mg_anns = [], mg_binds = core_binds, -- Stubs mg_rdr_env = emptyGlobalRdrEnv, mg_fix_env = emptyFixityEnv, mg_warns = NoWarnings, mg_foreign = NoStubs, mg_hpc_info = emptyHpcInfo False, mg_modBreaks = emptyModBreaks, mg_vect_info = noVectInfo, mg_safe_haskell = safe_mode, mg_trust_pkg = False, mg_dependent_files = dep_files } } ; tcCoreDump mod_guts ; return mod_guts }}}} mkFakeGroup :: [LTyClDecl a] -> HsGroup a mkFakeGroup decls -- Rather clumsy; lots of unused fields = emptyRdrGroup { hs_tyclds = [decls] } \end{code} %************************************************************************ %* * Type-checking the top level of a module %* * %************************************************************************ \begin{code} tcRnSrcDecls :: ModDetails -> [LHsDecl RdrName] -> TcM TcGblEnv -- Returns the variables free in the decls -- Reason: solely to report unused imports and bindings tcRnSrcDecls boot_iface decls = do { -- Do all the declarations ((tcg_env, tcl_env), lie) <- captureConstraints $ tc_rn_src_decls boot_iface decls ; ; traceTc "Tc8" empty ; ; setEnvs (tcg_env, tcl_env) $ do { -- Finish simplifying class constraints -- -- simplifyTop deals with constant or ambiguous InstIds. -- How could there be ambiguous ones? They can only arise if a -- top-level decl falls under the monomorphism restriction -- and no subsequent decl instantiates its type. -- -- We do this after checkMain, so that we use the type info -- that checkMain adds -- -- We do it with both global and local env in scope: -- * the global env exposes the instances to simplifyTop -- * the local env exposes the local Ids to simplifyTop, -- so that we get better error messages (monomorphism restriction) new_ev_binds <- {-# SCC "simplifyTop" #-} simplifyTop lie ; traceTc "Tc9" empty ; failIfErrsM ; -- Don't zonk if there have been errors -- It's a waste of time; and we may get debug warnings -- about strangely-typed TyCons! -- Zonk the final code. This must be done last. -- Even simplifyTop may do some unification. -- This pass also warns about missing type signatures let { TcGblEnv { tcg_type_env = type_env, tcg_binds = binds, tcg_sigs = sig_ns, tcg_ev_binds = cur_ev_binds, tcg_imp_specs = imp_specs, tcg_rules = rules, tcg_vects = vects, tcg_fords = fords } = tcg_env ; all_ev_binds = cur_ev_binds `unionBags` new_ev_binds } ; (bind_ids, ev_binds', binds', fords', imp_specs', rules', vects') <- {-# SCC "zonkTopDecls" #-} zonkTopDecls all_ev_binds binds sig_ns rules vects imp_specs fords ; let { final_type_env = extendTypeEnvWithIds type_env bind_ids ; tcg_env' = tcg_env { tcg_binds = binds', tcg_ev_binds = ev_binds', tcg_imp_specs = imp_specs', tcg_rules = rules', tcg_vects = vects', tcg_fords = fords' } } ; setGlobalTypeEnv tcg_env' final_type_env } } tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv) -- Loops around dealing with each top level inter-splice group -- in turn, until it's dealt with the entire module tc_rn_src_decls boot_details ds = {-# SCC "tc_rn_src_decls" #-} do { (first_group, group_tail) <- findSplice ds ; -- If ds is [] we get ([], Nothing) -- The extra_deps are needed while renaming type and class declarations -- See Note [Extra dependencies from .hs-boot files] in RnSource let { extra_deps = map tyConName (typeEnvTyCons (md_types boot_details)) } ; -- Deal with decls up to, but not including, the first splice (tcg_env, rn_decls) <- rnTopSrcDecls extra_deps first_group ; -- rnTopSrcDecls fails if there are any errors (tcg_env, tcl_env) <- setGblEnv tcg_env $ tcTopSrcDecls boot_details rn_decls ; -- If there is no splice, we're nearly done setEnvs (tcg_env, tcl_env) $ case group_tail of { Nothing -> do { tcg_env <- checkMain ; -- Check for `main' return (tcg_env, tcl_env) } ; #ifndef GHCI -- There shouldn't be a splice Just (SpliceDecl {}, _) -> do { failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler") #else -- If there's a splice, we must carry on Just (SpliceDecl splice_expr _, rest_ds) -> do { -- Rename the splice expression, and get its supporting decls (rn_splice_expr, splice_fvs) <- checkNoErrs (rnLExpr splice_expr) ; -- checkNoErrs: don't typecheck if renaming failed rnDump (ppr rn_splice_expr) ; -- Execute the splice spliced_decls <- tcSpliceDecls rn_splice_expr ; -- Glue them on the front of the remaining decls and loop setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $ tc_rn_src_decls boot_details (spliced_decls ++ rest_ds) #endif /* GHCI */ } } } \end{code} %************************************************************************ %* * Compiling hs-boot source files, and comparing the hi-boot interface with the real thing %* * %************************************************************************ \begin{code} tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv tcRnHsBootDecls decls = do { (first_group, group_tail) <- findSplice decls -- Rename the declarations ; (tcg_env, HsGroup { hs_tyclds = tycl_decls, hs_instds = inst_decls, hs_derivds = deriv_decls, hs_fords = for_decls, hs_defds = def_decls, hs_ruleds = rule_decls, hs_vects = vect_decls, hs_annds = _, hs_valds = val_binds }) <- rnTopSrcDecls [] first_group -- The empty list is for extra dependencies coming from .hs-boot files -- See Note [Extra dependencies from .hs-boot files] in RnSource ; (gbl_env, lie) <- captureConstraints $ setGblEnv tcg_env $ do { -- Check for illegal declarations ; case group_tail of Just (SpliceDecl d _, _) -> badBootDecl "splice" d Nothing -> return () ; mapM_ (badBootDecl "foreign") for_decls ; mapM_ (badBootDecl "default") def_decls ; mapM_ (badBootDecl "rule") rule_decls ; mapM_ (badBootDecl "vect") vect_decls -- Typecheck type/class decls ; traceTc "Tc2" empty ; tcg_env <- tcTyAndClassDecls emptyModDetails tycl_decls ; setGblEnv tcg_env $ do { -- Typecheck instance decls -- Family instance declarations are rejected here ; traceTc "Tc3" empty ; (tcg_env, inst_infos, _deriv_binds) <- tcInstDecls1 (concat tycl_decls) inst_decls deriv_decls ; setGblEnv tcg_env $ do { -- Typecheck value declarations ; traceTc "Tc5" empty ; val_ids <- tcHsBootSigs val_binds -- Wrap up -- No simplification or zonking to do ; traceTc "Tc7a" empty ; gbl_env <- getGblEnv -- Make the final type-env -- Include the dfun_ids so that their type sigs -- are written into the interface file. ; let { type_env0 = tcg_type_env gbl_env ; type_env1 = extendTypeEnvWithIds type_env0 val_ids ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids ; dfun_ids = map iDFunId inst_infos } ; setGlobalTypeEnv gbl_env type_env2 }}} ; traceTc "boot" (ppr lie); return gbl_env } badBootDecl :: String -> Located decl -> TcM () badBootDecl what (L loc _) = addErrAt loc (char 'A' <+> text what <+> ptext (sLit "declaration is not (currently) allowed in a hs-boot file")) \end{code} Once we've typechecked the body of the module, we want to compare what we've found (gathered in a TypeEnv) with the hi-boot details (if any). \begin{code} checkHiBootIface :: TcGblEnv -> ModDetails -> TcM TcGblEnv -- Compare the hi-boot file for this module (if there is one) -- with the type environment we've just come up with -- In the common case where there is no hi-boot file, the list -- of boot_names is empty. -- -- The bindings we return give bindings for the dfuns defined in the -- hs-boot file, such as $fbEqT = $fEqT checkHiBootIface tcg_env@(TcGblEnv { tcg_src = hs_src, tcg_binds = binds, tcg_insts = local_insts, tcg_type_env = local_type_env, tcg_exports = local_exports }) (ModDetails { md_insts = boot_insts, md_fam_insts = boot_fam_insts, md_types = boot_type_env, md_exports = boot_exports }) | isHsBoot hs_src -- Current module is already a hs-boot file! = return tcg_env | otherwise = do { traceTc "checkHiBootIface" $ vcat [ ppr boot_type_env, ppr boot_insts, ppr boot_exports] -- Check the exports of the boot module, one by one ; mapM_ check_export boot_exports -- Check for no family instances ; unless (null boot_fam_insts) $ panic ("TcRnDriver.checkHiBootIface: Cannot handle family " ++ "instances in boot files yet...") -- FIXME: Why? The actual comparison is not hard, but what would -- be the equivalent to the dfun bindings returned for class -- instances? We can't easily equate tycons... -- Check instance declarations ; mb_dfun_prs <- mapM check_inst boot_insts ; let dfun_prs = catMaybes mb_dfun_prs boot_dfuns = map fst dfun_prs dfun_binds = listToBag [ mkVarBind boot_dfun (nlHsVar dfun) | (boot_dfun, dfun) <- dfun_prs ] type_env' = extendTypeEnvWithIds local_type_env boot_dfuns tcg_env' = tcg_env { tcg_binds = binds `unionBags` dfun_binds } ; failIfErrsM ; setGlobalTypeEnv tcg_env' type_env' } -- Update the global type env *including* the knot-tied one -- so that if the source module reads in an interface unfolding -- mentioning one of the dfuns from the boot module, then it -- can "see" that boot dfun. See Trac #4003 where check_export boot_avail -- boot_avail is exported by the boot iface | name `elem` dfun_names = return () | isWiredInName name = return () -- No checking for wired-in names. In particular, -- 'error' is handled by a rather gross hack -- (see comments in GHC.Err.hs-boot) -- Check that the actual module exports the same thing | not (null missing_names) = addErrAt (nameSrcSpan (head missing_names)) (missingBootThing (head missing_names) "exported by") -- If the boot module does not *define* the thing, we are done -- (it simply re-exports it, and names match, so nothing further to do) | isNothing mb_boot_thing = return () -- Check that the actual module also defines the thing, and -- then compare the definitions | Just real_thing <- lookupTypeEnv local_type_env name, Just boot_thing <- mb_boot_thing = when (not (checkBootDecl boot_thing real_thing)) $ addErrAt (nameSrcSpan (getName boot_thing)) (let boot_decl = tyThingToIfaceDecl (fromJust mb_boot_thing) real_decl = tyThingToIfaceDecl real_thing in bootMisMatch real_thing boot_decl real_decl) | otherwise = addErrTc (missingBootThing name "defined in") where name = availName boot_avail mb_boot_thing = lookupTypeEnv boot_type_env name missing_names = case lookupNameEnv local_export_env name of Nothing -> [name] Just avail -> availNames boot_avail `minusList` availNames avail dfun_names = map getName boot_insts local_export_env :: NameEnv AvailInfo local_export_env = availsToNameEnv local_exports check_inst :: Instance -> TcM (Maybe (Id, Id)) -- Returns a pair of the boot dfun in terms of the equivalent real dfun check_inst boot_inst = case [dfun | inst <- local_insts, let dfun = instanceDFunId inst, idType dfun `eqType` boot_inst_ty ] of [] -> do { traceTc "check_inst" (vcat [ text "local_insts" <+> vcat (map (ppr . idType . instanceDFunId) local_insts) , text "boot_inst" <+> ppr boot_inst , text "boot_inst_ty" <+> ppr boot_inst_ty ]) ; addErrTc (instMisMatch boot_inst); return Nothing } (dfun:_) -> return (Just (local_boot_dfun, dfun)) where boot_dfun = instanceDFunId boot_inst boot_inst_ty = idType boot_dfun local_boot_dfun = Id.mkExportedLocalId (idName boot_dfun) boot_inst_ty -- This has to compare the TyThing from the .hi-boot file to the TyThing -- in the current source file. We must be careful to allow alpha-renaming -- where appropriate, and also the boot declaration is allowed to omit -- constructors and class methods. -- -- See rnfail055 for a good test of this stuff. checkBootDecl :: TyThing -> TyThing -> Bool checkBootDecl (AnId id1) (AnId id2) = ASSERT(id1 == id2) (idType id1 `eqType` idType id2) checkBootDecl (ATyCon tc1) (ATyCon tc2) = checkBootTyCon tc1 tc2 checkBootDecl (ADataCon dc1) (ADataCon _) = pprPanic "checkBootDecl" (ppr dc1) checkBootDecl _ _ = False -- probably shouldn't happen ---------------- checkBootTyCon :: TyCon -> TyCon -> Bool checkBootTyCon tc1 tc2 | not (eqKind (tyConKind tc1) (tyConKind tc2)) = False -- First off, check the kind | Just c1 <- tyConClass_maybe tc1 , Just c2 <- tyConClass_maybe tc2 = let (clas_tyvars1, clas_fds1, sc_theta1, _, ats1, op_stuff1) = classExtraBigSig c1 (clas_tyvars2, clas_fds2, sc_theta2, _, ats2, op_stuff2) = classExtraBigSig c2 env0 = mkRnEnv2 emptyInScopeSet env = rnBndrs2 env0 clas_tyvars1 clas_tyvars2 eqSig (id1, def_meth1) (id2, def_meth2) = idName id1 == idName id2 && eqTypeX env op_ty1 op_ty2 && def_meth1 == def_meth2 where (_, rho_ty1) = splitForAllTys (idType id1) op_ty1 = funResultTy rho_ty1 (_, rho_ty2) = splitForAllTys (idType id2) op_ty2 = funResultTy rho_ty2 eqAT (tc1, def_ats1) (tc2, def_ats2) = checkBootTyCon tc1 tc2 && eqListBy eqATDef def_ats1 def_ats2 -- Ignore the location of the defaults eqATDef (ATD tvs1 ty_pats1 ty1 _loc1) (ATD tvs2 ty_pats2 ty2 _loc2) = eqListBy same_kind tvs1 tvs2 && eqListBy (eqTypeX env) ty_pats1 ty_pats2 && eqTypeX env ty1 ty2 where env = rnBndrs2 env0 tvs1 tvs2 eqFD (as1,bs1) (as2,bs2) = eqListBy (eqTypeX env) (mkTyVarTys as1) (mkTyVarTys as2) && eqListBy (eqTypeX env) (mkTyVarTys bs1) (mkTyVarTys bs2) same_kind tv1 tv2 = eqKind (tyVarKind tv1) (tyVarKind tv2) in eqListBy same_kind clas_tyvars1 clas_tyvars2 && -- Checks kind of class eqListBy eqFD clas_fds1 clas_fds2 && (null sc_theta1 && null op_stuff1 && null ats1 || -- Above tests for an "abstract" class eqListBy (eqPredX env) sc_theta1 sc_theta2 && eqListBy eqSig op_stuff1 op_stuff2 && eqListBy eqAT ats1 ats2) | isSynTyCon tc1 && isSynTyCon tc2 = ASSERT(tc1 == tc2) let tvs1 = tyConTyVars tc1; tvs2 = tyConTyVars tc2 env = rnBndrs2 env0 tvs1 tvs2 eqSynRhs SynFamilyTyCon SynFamilyTyCon = True eqSynRhs (SynonymTyCon t1) (SynonymTyCon t2) = eqTypeX env t1 t2 eqSynRhs _ _ = False in equalLength tvs1 tvs2 && eqSynRhs (synTyConRhs tc1) (synTyConRhs tc2) | isAlgTyCon tc1 && isAlgTyCon tc2 = ASSERT(tc1 == tc2) eqKind (tyConKind tc1) (tyConKind tc2) && eqListBy eqPred (tyConStupidTheta tc1) (tyConStupidTheta tc2) && eqAlgRhs (algTyConRhs tc1) (algTyConRhs tc2) | isForeignTyCon tc1 && isForeignTyCon tc2 = eqKind (tyConKind tc1) (tyConKind tc2) && tyConExtName tc1 == tyConExtName tc2 | otherwise = False where env0 = mkRnEnv2 emptyInScopeSet eqAlgRhs (AbstractTyCon dis1) rhs2 | dis1 = isDistinctAlgRhs rhs2 --Check compatibility | otherwise = True eqAlgRhs DataFamilyTyCon{} DataFamilyTyCon{} = True eqAlgRhs tc1@DataTyCon{} tc2@DataTyCon{} = eqListBy eqCon (data_cons tc1) (data_cons tc2) eqAlgRhs tc1@NewTyCon{} tc2@NewTyCon{} = eqCon (data_con tc1) (data_con tc2) eqAlgRhs _ _ = False eqCon c1 c2 = dataConName c1 == dataConName c2 && dataConIsInfix c1 == dataConIsInfix c2 && dataConStrictMarks c1 == dataConStrictMarks c2 && dataConFieldLabels c1 == dataConFieldLabels c2 && eqType (dataConUserType c1) (dataConUserType c2) ---------------- missingBootThing :: Name -> String -> SDoc missingBootThing name what = ppr name <+> ptext (sLit "is exported by the hs-boot file, but not") <+> text what <+> ptext (sLit "the module") bootMisMatch :: TyThing -> IfaceDecl -> IfaceDecl -> SDoc bootMisMatch thing boot_decl real_decl = vcat [ppr thing <+> ptext (sLit "has conflicting definitions in the module and its hs-boot file"), ptext (sLit "Main module:") <+> ppr real_decl, ptext (sLit "Boot file: ") <+> ppr boot_decl] instMisMatch :: Instance -> SDoc instMisMatch inst = hang (ppr inst) 2 (ptext (sLit "is defined in the hs-boot file, but not in the module itself")) \end{code} %************************************************************************ %* * Type-checking the top level of a module %* * %************************************************************************ tcRnGroup takes a bunch of top-level source-code declarations, and * renames them * gets supporting declarations from interface files * typechecks them * zonks them * and augments the TcGblEnv with the results In Template Haskell it may be called repeatedly for each group of declarations. It expects there to be an incoming TcGblEnv in the monad; it augments it and returns the new TcGblEnv. \begin{code} ------------------------------------------------ rnTopSrcDecls :: [Name] -> HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name) -- Fails if there are any errors rnTopSrcDecls extra_deps group = do { -- Rename the source decls traceTc "rn12" empty ; (tcg_env, rn_decls) <- checkNoErrs $ rnSrcDecls extra_deps group ; traceTc "rn13" empty ; -- save the renamed syntax, if we want it let { tcg_env' | Just grp <- tcg_rn_decls tcg_env = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) } | otherwise = tcg_env }; -- Dump trace of renaming part rnDump (ppr rn_decls) ; return (tcg_env', rn_decls) } ------------------------------------------------ tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv) tcTopSrcDecls boot_details (HsGroup { hs_tyclds = tycl_decls, hs_instds = inst_decls, hs_derivds = deriv_decls, hs_fords = foreign_decls, hs_defds = default_decls, hs_annds = annotation_decls, hs_ruleds = rule_decls, hs_vects = vect_decls, hs_valds = val_binds }) = do { -- Type-check the type and class decls, and all imported decls -- The latter come in via tycl_decls traceTc "Tc2" empty ; tcg_env <- tcTyAndClassDecls boot_details tycl_decls ; setGblEnv tcg_env $ do { -- Source-language instances, including derivings, -- and import the supporting declarations traceTc "Tc3" empty ; (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 (concat tycl_decls) inst_decls deriv_decls; setGblEnv tcg_env $ do { -- Foreign import declarations next. traceTc "Tc4" empty ; (fi_ids, fi_decls) <- tcForeignImports foreign_decls ; tcExtendGlobalValEnv fi_ids $ do { -- Default declarations traceTc "Tc4a" empty ; default_tys <- tcDefaults default_decls ; updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do { -- Now GHC-generated derived bindings, generics, and selectors -- Do not generate warnings from compiler-generated code; -- hence the use of discardWarnings tc_envs <- discardWarnings (tcTopBinds deriv_binds) ; setEnvs tc_envs $ do { -- Value declarations next traceTc "Tc5" empty ; tc_envs@(tcg_env, tcl_env) <- tcTopBinds val_binds; setEnvs tc_envs $ do { -- Environment doesn't change now -- Second pass over class and instance declarations, -- now using the kind-checked decls traceTc "Tc6" empty ; inst_binds <- tcInstDecls2 (concat tycl_decls) inst_infos ; -- Foreign exports traceTc "Tc7" empty ; (foe_binds, foe_decls) <- tcForeignExports foreign_decls ; -- Annotations annotations <- tcAnnotations annotation_decls ; -- Rules rules <- tcRules rule_decls ; -- Vectorisation declarations vects <- tcVectDecls vect_decls ; -- Wrap up traceTc "Tc7a" empty ; let { all_binds = inst_binds `unionBags` foe_binds ; sig_names = mkNameSet (collectHsValBinders val_binds) `minusNameSet` getTypeSigNames val_binds -- Extend the GblEnv with the (as yet un-zonked) -- bindings, rules, foreign decls ; tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds , tcg_sigs = tcg_sigs tcg_env `unionNameSets` sig_names , tcg_rules = tcg_rules tcg_env ++ rules , tcg_vects = tcg_vects tcg_env ++ vects , tcg_anns = tcg_anns tcg_env ++ annotations , tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ; return (tcg_env', tcl_env) }}}}}}} \end{code} %************************************************************************ %* * Checking for 'main' %* * %************************************************************************ \begin{code} checkMain :: TcM TcGblEnv -- If we are in module Main, check that 'main' is defined. checkMain = do { tcg_env <- getGblEnv ; dflags <- getDOpts ; check_main dflags tcg_env } check_main :: DynFlags -> TcGblEnv -> TcM TcGblEnv check_main dflags tcg_env | mod /= main_mod = traceTc "checkMain not" (ppr main_mod <+> ppr mod) >> return tcg_env | otherwise = do { mb_main <- lookupGlobalOccRn_maybe main_fn -- Check that 'main' is in scope -- It might be imported from another module! ; case mb_main of { Nothing -> do { traceTc "checkMain fail" (ppr main_mod <+> ppr main_fn) ; complain_no_main ; return tcg_env } ; Just main_name -> do { traceTc "checkMain found" (ppr main_mod <+> ppr main_fn) ; let loc = srcLocSpan (getSrcLoc main_name) ; ioTyCon <- tcLookupTyCon ioTyConName ; res_ty <- newFlexiTyVarTy liftedTypeKind ; main_expr <- addErrCtxt mainCtxt $ tcMonoExpr (L loc (HsVar main_name)) (mkTyConApp ioTyCon [res_ty]) -- See Note [Root-main Id] -- Construct the binding -- :Main.main :: IO res_ty = runMainIO res_ty main ; run_main_id <- tcLookupId runMainIOName ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN (mkVarOccFS (fsLit "main")) (getSrcSpan main_name) ; root_main_id = Id.mkExportedLocalId root_main_name (mkTyConApp ioTyCon [res_ty]) ; co = mkWpTyApps [res_ty] ; rhs = nlHsApp (mkLHsWrap co (nlHsVar run_main_id)) main_expr ; main_bind = mkVarBind root_main_id rhs } ; return (tcg_env { tcg_main = Just main_name, tcg_binds = tcg_binds tcg_env `snocBag` main_bind, tcg_dus = tcg_dus tcg_env `plusDU` usesOnly (unitFV main_name) -- Record the use of 'main', so that we don't -- complain about it being defined but not used }) }}} where mod = tcg_mod tcg_env main_mod = mainModIs dflags main_fn = getMainFun dflags complain_no_main | ghcLink dflags == LinkInMemory = return () | otherwise = failWithTc noMainMsg -- In interactive mode, don't worry about the absence of 'main' -- In other modes, fail altogether, so that we don't go on -- and complain a second time when processing the export list. mainCtxt = ptext (sLit "When checking the type of the") <+> pp_main_fn noMainMsg = ptext (sLit "The") <+> pp_main_fn <+> ptext (sLit "is not defined in module") <+> quotes (ppr main_mod) pp_main_fn = ppMainFn main_fn ppMainFn :: RdrName -> SDoc ppMainFn main_fn | main_fn == main_RDR_Unqual = ptext (sLit "function") <+> quotes (ppr main_fn) | otherwise = ptext (sLit "main function") <+> quotes (ppr main_fn) -- | Get the unqualified name of the function to use as the \"main\" for the main module. -- Either returns the default name or the one configured on the command line with -main-is getMainFun :: DynFlags -> RdrName getMainFun dflags = case (mainFunIs dflags) of Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) Nothing -> main_RDR_Unqual checkMainExported :: TcGblEnv -> TcM () checkMainExported tcg_env = do dflags <- getDOpts case tcg_main tcg_env of Nothing -> return () -- not the main module Just main_name -> do let main_mod = mainModIs dflags checkTc (main_name `elem` concatMap availNames (tcg_exports tcg_env)) $ ptext (sLit "The") <+> ppMainFn (nameRdrName main_name) <+> ptext (sLit "is not exported by module") <+> quotes (ppr main_mod) \end{code} Note [Root-main Id] ~~~~~~~~~~~~~~~~~~~ The function that the RTS invokes is always :Main.main, which we call root_main_id. (Because GHC allows the user to have a module not called Main as the main module, we can't rely on the main function being called "Main.main". That's why root_main_id has a fixed module ":Main".) This is unusual: it's a LocalId whose Name has a Module from another module. Tiresomely, we must filter it out again in MkIface, les we get two defns for 'main' in the interface file! %********************************************************* %* * GHCi stuff %* * %********************************************************* \begin{code} setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a setInteractiveContext hsc_env icxt thing_inside = let -- Initialise the tcg_inst_env with instances from all home modules. -- This mimics the more selective call to hptInstances in tcRnModule. (home_insts, home_fam_insts) = hptInstances hsc_env (\_ -> True) (ic_insts, ic_finsts) = ic_instances icxt -- Note [GHCi temporary Ids] -- Ideally we would just make a type_env from ic_tythings -- and ic_sys_vars, adding in implicit things. However, Ids -- bound interactively might have some free type variables -- (RuntimeUnk things), and if we don't register these free -- TyVars as global TyVars then the typechecker will try to -- quantify over them and fall over in zonkQuantifiedTyVar. -- -- So we must add any free TyVars to the typechecker's global -- TyVar set. This is what happens when the local environment -- is extended, so we use tcExtendGhciEnv below which extends -- the local environment with the Ids. -- -- However, any Ids bound this way will shadow other Ids in -- the GlobalRdrEnv, so we have to be careful to only add Ids -- which are visible in the GlobalRdrEnv. -- -- Perhaps it would be better to just extend the global TyVar -- list from the free tyvars in the Ids here? Anyway, at least -- this hack is localised. -- -- Note [delete shadowed tcg_rdr_env entries] -- We also *delete* entries from tcg_rdr_env that we have -- shadowed in the local env (see above). This isn't strictly -- necessary, but in an out-of-scope error when GHC suggests -- names it can be confusing to see multiple identical -- entries. (#5564) -- (tmp_ids, types_n_classes) = partitionWith sel_id (ic_tythings icxt) where sel_id (AnId id) = Left id sel_id other = Right other type_env = mkTypeEnvWithImplicits (map AnId (ic_sys_vars icxt) ++ types_n_classes) visible_tmp_ids = filter visible tmp_ids where visible id = not (null (lookupGRE_Name (ic_rn_gbl_env icxt) (idName id))) con_fields = [ (dataConName c, dataConFieldLabels c) | ATyCon t <- types_n_classes , c <- tyConDataCons t ] in updGblEnv (\env -> env { tcg_rdr_env = delListFromOccEnv (ic_rn_gbl_env icxt) (map getOccName visible_tmp_ids) -- Note [delete shadowed tcg_rdr_env entries] , tcg_type_env = type_env , tcg_inst_env = extendInstEnvList (extendInstEnvList (tcg_inst_env env) ic_insts) home_insts , tcg_fam_inst_env = extendFamInstEnvList (extendFamInstEnvList (tcg_fam_inst_env env) ic_finsts) home_fam_insts , tcg_field_env = RecFields (mkNameEnv con_fields) (mkNameSet (concatMap snd con_fields)) -- setting tcg_field_env is necessary to make RecordWildCards work -- (test: ghci049) }) $ tcExtendGhciEnv visible_tmp_ids $ -- Note [GHCi temporary Ids] thing_inside \end{code} \begin{code} #ifdef GHCI tcRnStmt :: HscEnv -> InteractiveContext -> LStmt RdrName -> IO (Messages, Maybe ([Id], LHsExpr Id)) -- The returned [Id] is the list of new Ids bound by -- this statement. It can be used to extend the -- InteractiveContext via extendInteractiveContext. -- -- The returned TypecheckedHsExpr is of type IO [ () ], -- a list of the bound values, coerced to (). tcRnStmt hsc_env ictxt rdr_stmt = initTcPrintErrors hsc_env iNTERACTIVE $ setInteractiveContext hsc_env ictxt $ do { -- Rename; use CmdLineMode because tcRnStmt is only used interactively (([rn_stmt], _), fvs) <- rnStmts GhciStmt [rdr_stmt] $ \_ -> return ((), emptyFVs) ; traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ; failIfErrsM ; rnDump (ppr rn_stmt) ; -- The real work is done here (bound_ids, tc_expr) <- mkPlan rn_stmt ; zonked_expr <- zonkTopLExpr tc_expr ; zonked_ids <- zonkTopBndrs bound_ids ; -- None of the Ids should be of unboxed type, because we -- cast them all to HValues in the end! mapM_ bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ; traceTc "tcs 1" empty ; let { global_ids = map globaliseAndTidyId zonked_ids } ; -- Note [Interactively-bound Ids in GHCi] {- --------------------------------------------- At one stage I removed any shadowed bindings from the type_env; they are inaccessible but might, I suppose, cause a space leak if we leave them there. However, with Template Haskell they aren't necessarily inaccessible. Consider this GHCi session Prelude> let f n = n * 2 :: Int Prelude> fName <- runQ [| f |] Prelude> $(return $ AppE fName (LitE (IntegerL 7))) 14 Prelude> let f n = n * 3 :: Int Prelude> $(return $ AppE fName (LitE (IntegerL 7))) In the last line we use 'fName', which resolves to the *first* 'f' in scope. If we delete it from the type env, GHCi crashes because it doesn't expect that. Hence this code is commented out -------------------------------------------------- -} dumpOptTcRn Opt_D_dump_tc (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids, text "Typechecked expr" <+> ppr zonked_expr]) ; return (global_ids, zonked_expr) } where bad_unboxed id = addErr (sep [ptext (sLit "GHCi can't bind a variable of unlifted type:"), nest 2 (ppr id <+> dcolon <+> ppr (idType id))]) \end{code} Note [Interactively-bound Ids in GHCi] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The Ids bound by previous Stmts in GHCi are currently a) GlobalIds b) with an Internal Name (not External) c) and a tidied type (a) They must be GlobalIds (not LocalIds) otherwise when we come to compile an expression using these ids later, the byte code generator will consider the occurrences to be free rather than global. (b) They retain their Internal names becuase we don't have a suitable Module to name them with. We could revisit this choice. (c) Their types are tidied. This is important, because :info may ask to look at them, and :info expects the things it looks up to have tidy types -------------------------------------------------------------------------- Typechecking Stmts in GHCi Here is the grand plan, implemented in tcUserStmt What you type The IO [HValue] that hscStmt returns ------------- ------------------------------------ let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...] bindings: [x,y,...] pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...] bindings: [x,y,...] expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it] [NB: result not printed] bindings: [it] expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it] result showable) bindings: [it] expr (of non-IO type, result not showable) ==> error \begin{code} --------------------------- type PlanResult = ([Id], LHsExpr Id) type Plan = TcM PlanResult runPlans :: [Plan] -> TcM PlanResult -- Try the plans in order. If one fails (by raising an exn), try the next. -- If one succeeds, take it. runPlans [] = panic "runPlans" runPlans [p] = p runPlans (p:ps) = tryTcLIE_ (runPlans ps) p -------------------- mkPlan :: LStmt Name -> TcM PlanResult mkPlan (L loc (ExprStmt expr _ _ _)) -- An expression typed at the prompt = do { uniq <- newUnique -- is treated very specially ; let fresh_it = itName uniq loc the_bind = L loc $ mkTopFunBind (L loc fresh_it) matches matches = [mkMatch [] expr emptyLocalBinds] let_stmt = L loc $ LetStmt $ HsValBinds $ ValBindsOut [(NonRecursive,unitBag the_bind)] [] bind_stmt = L loc $ BindStmt (L loc (VarPat fresh_it)) expr (HsVar bindIOName) noSyntaxExpr print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it)) (HsVar thenIOName) noSyntaxExpr placeHolderType -- The plans are: -- [it <- e; print it] but not if it::() -- [it <- e] -- [let it = e; print it] ; runPlans [ -- Plan A do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it] ; it_ty <- zonkTcType (idType it_id) ; when (isUnitTy it_ty) failM ; return stuff }, -- Plan B; a naked bind statment tcGhciStmts [bind_stmt], -- Plan C; check that the let-binding is typeable all by itself. -- If not, fail; if so, try to print it. -- The two-step process avoids getting two errors: one from -- the expression itself, and one from the 'print it' part -- This two-step story is very clunky, alas do { _ <- checkNoErrs (tcGhciStmts [let_stmt]) --- checkNoErrs defeats the error recovery of let-bindings ; tcGhciStmts [let_stmt, print_it] } ]} mkPlan stmt@(L loc (BindStmt {})) | [v] <- collectLStmtBinders stmt -- One binder, for a bind stmt = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v)) (HsVar thenIOName) noSyntaxExpr placeHolderType ; print_bind_result <- doptM Opt_PrintBindResult ; let print_plan = do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v] ; v_ty <- zonkTcType (idType v_id) ; when (isUnitTy v_ty || not (isTauTy v_ty)) failM ; return stuff } -- The plans are: -- [stmt; print v] but not if v::() -- [stmt] ; runPlans ((if print_bind_result then [print_plan] else []) ++ [tcGhciStmts [stmt]]) } mkPlan stmt = tcGhciStmts [stmt] --------------------------- tcGhciStmts :: [LStmt Name] -> TcM PlanResult tcGhciStmts stmts = do { ioTyCon <- tcLookupTyCon ioTyConName ; ret_id <- tcLookupId returnIOName ; -- return @ IO let { ret_ty = mkListTy unitTy ; io_ret_ty = mkTyConApp ioTyCon [ret_ty] ; tc_io_stmts stmts = tcStmtsAndThen GhciStmt tcDoStmt stmts io_ret_ty ; names = collectLStmtsBinders stmts ; } ; -- OK, we're ready to typecheck the stmts traceTc "TcRnDriver.tcGhciStmts: tc stmts" empty ; ((tc_stmts, ids), lie) <- captureConstraints $ tc_io_stmts stmts $ \ _ -> mapM tcLookupId names ; -- Look up the names right in the middle, -- where they will all be in scope -- Simplify the context traceTc "TcRnDriver.tcGhciStmts: simplify ctxt" empty ; const_binds <- checkNoErrs (simplifyInteractive lie) ; -- checkNoErrs ensures that the plan fails if context redn fails traceTc "TcRnDriver.tcGhciStmts: done" empty ; let { -- mk_return builds the expression -- returnIO @ [()] [coerce () x, .., coerce () z] -- -- Despite the inconvenience of building the type applications etc, -- this *has* to be done in type-annotated post-typecheck form -- because we are going to return a list of *polymorphic* values -- coerced to type (). If we built a *source* stmt -- return [coerce x, ..., coerce z] -- then the type checker would instantiate x..z, and we wouldn't -- get their *polymorphic* values. (And we'd get ambiguity errs -- if they were overloaded, since they aren't applied to anything.) ret_expr = nlHsApp (nlHsTyApp ret_id [ret_ty]) (noLoc $ ExplicitList unitTy (map mk_item ids)) ; mk_item id = nlHsApp (nlHsTyApp unsafeCoerceId [idType id, unitTy]) (nlHsVar id) ; stmts = tc_stmts ++ [noLoc (mkLastStmt ret_expr)] } ; return (ids, mkHsDictLet (EvBinds const_binds) $ noLoc (HsDo GhciStmt stmts io_ret_ty)) } \end{code} tcRnExpr just finds the type of an expression \begin{code} tcRnExpr :: HscEnv -> InteractiveContext -> LHsExpr RdrName -> IO (Messages, Maybe Type) tcRnExpr hsc_env ictxt rdr_expr = initTcPrintErrors hsc_env iNTERACTIVE $ setInteractiveContext hsc_env ictxt $ do { (rn_expr, _fvs) <- rnLExpr rdr_expr ; failIfErrsM ; -- Now typecheck the expression; -- it might have a rank-2 type (e.g. :t runST) uniq <- newUnique ; let { fresh_it = itName uniq (getLoc rdr_expr) } ; ((_tc_expr, res_ty), lie) <- captureConstraints (tcInferRho rn_expr) ; ((qtvs, dicts, _, _), lie_top) <- captureConstraints $ {-# SCC "simplifyInfer" #-} simplifyInfer True {- Free vars are closed -} False {- No MR for now -} [(fresh_it, res_ty)] lie ; _ <- simplifyInteractive lie_top ; -- Ignore the dicionary bindings let { all_expr_ty = mkForAllTys qtvs (mkPiTypes dicts res_ty) } ; zonkTcType all_expr_ty } -------------------------- tcRnImportDecls :: HscEnv -> [LImportDecl RdrName] -> IO (Messages, Maybe GlobalRdrEnv) tcRnImportDecls hsc_env import_decls = initTcPrintErrors hsc_env iNTERACTIVE $ do { gbl_env <- tcRnImports hsc_env iNTERACTIVE import_decls ; return (tcg_rdr_env gbl_env) } \end{code} tcRnType just finds the kind of a type \begin{code} tcRnType :: HscEnv -> InteractiveContext -> Bool -- Normalise the returned type -> LHsType RdrName -> IO (Messages, Maybe (Type, Kind)) tcRnType hsc_env ictxt normalise rdr_type = initTcPrintErrors hsc_env iNTERACTIVE $ setInteractiveContext hsc_env ictxt $ do { rn_type <- rnLHsType GHCiCtx rdr_type ; failIfErrsM ; -- Now kind-check the type -- It can have any rank or kind ty <- tcHsSigType GhciCtxt rn_type ; ty' <- if normalise then do { fam_envs <- tcGetFamInstEnvs ; return (snd (normaliseType fam_envs ty)) } -- normaliseType returns a coercion -- which we discard else return ty ; return (ty', typeKind ty) } \end{code} tcRnDeclsi exists to allow class, data, and other declarations in GHCi. \begin{code} tcRnDeclsi :: HscEnv -> InteractiveContext -> [LHsDecl RdrName] -> IO (Messages, Maybe TcGblEnv) tcRnDeclsi hsc_env ictxt local_decls = initTcPrintErrors hsc_env iNTERACTIVE $ setInteractiveContext hsc_env ictxt $ do ((tcg_env, tclcl_env), lie) <- captureConstraints $ tc_rn_src_decls emptyModDetails local_decls setEnvs (tcg_env, tclcl_env) $ do new_ev_binds <- simplifyTop lie failIfErrsM let TcGblEnv { tcg_type_env = type_env, tcg_binds = binds, tcg_sigs = sig_ns, tcg_ev_binds = cur_ev_binds, tcg_imp_specs = imp_specs, tcg_rules = rules, tcg_vects = vects, tcg_fords = fords } = tcg_env all_ev_binds = cur_ev_binds `unionBags` new_ev_binds (bind_ids, ev_binds', binds', fords', imp_specs', rules', vects') <- zonkTopDecls all_ev_binds binds sig_ns rules vects imp_specs fords let --global_ids = map globaliseAndTidyId bind_ids final_type_env = extendTypeEnvWithIds type_env bind_ids --global_ids tcg_env' = tcg_env { tcg_binds = binds', tcg_ev_binds = ev_binds', tcg_imp_specs = imp_specs', tcg_rules = rules', tcg_vects = vects', tcg_fords = fords' } tcg_env'' <- setGlobalTypeEnv tcg_env' final_type_env return tcg_env'' #endif /* GHCi */ \end{code} %************************************************************************ %* * More GHCi stuff, to do with browsing and getting info %* * %************************************************************************ \begin{code} #ifdef GHCI -- | ASSUMES that the module is either in the 'HomePackageTable' or is -- a package module with an interface on disk. If neither of these is -- true, then the result will be an error indicating the interface -- could not be found. getModuleInterface :: HscEnv -> Module -> IO (Messages, Maybe ModIface) getModuleInterface hsc_env mod = initTc hsc_env HsSrcFile False iNTERACTIVE $ loadModuleInterface (ptext (sLit "getModuleInterface")) mod tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Messages, Maybe [Name]) tcRnLookupRdrName hsc_env rdr_name = initTcPrintErrors hsc_env iNTERACTIVE $ setInteractiveContext hsc_env (hsc_IC hsc_env) $ lookup_rdr_name rdr_name lookup_rdr_name :: RdrName -> TcM [Name] lookup_rdr_name rdr_name = do -- If the identifier is a constructor (begins with an -- upper-case letter), then we need to consider both -- constructor and type class identifiers. let rdr_names = dataTcOccs rdr_name -- results :: [Either Messages Name] results <- mapM (tryTcErrs . lookupOccRn) rdr_names traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]) -- The successful lookups will be (Just name) let (warns_s, good_names) = unzip [ (msgs, name) | (msgs, Just name) <- results] errs_s = [msgs | (msgs, Nothing) <- results] -- Fail if nothing good happened, else add warnings if null good_names then addMessages (head errs_s) >> failM -- No lookup succeeded, so -- pick the first error message and report it -- ToDo: If one of the errors is "could be Foo.X or Baz.X", -- while the other is "X is not in scope", -- we definitely want the former; but we might pick the latter else mapM_ addMessages warns_s -- Add deprecation warnings return good_names #endif tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing) tcRnLookupName hsc_env name = initTcPrintErrors hsc_env iNTERACTIVE $ setInteractiveContext hsc_env (hsc_IC hsc_env) $ tcRnLookupName' name -- To look up a name we have to look in the local environment (tcl_lcl) -- as well as the global environment, which is what tcLookup does. -- But we also want a TyThing, so we have to convert: tcRnLookupName' :: Name -> TcRn TyThing tcRnLookupName' name = do tcthing <- tcLookup name case tcthing of AGlobal thing -> return thing ATcId{tct_id=id} -> return (AnId id) _ -> panic "tcRnLookupName'" tcRnGetInfo :: HscEnv -> Name -> IO (Messages, Maybe (TyThing, Fixity, [Instance])) -- Used to implement :info in GHCi -- -- Look up a RdrName and return all the TyThings it might be -- A capitalised RdrName is given to us in the DataName namespace, -- but we want to treat it as *both* a data constructor -- *and* as a type or class constructor; -- hence the call to dataTcOccs, and we return up to two results tcRnGetInfo hsc_env name = initTcPrintErrors hsc_env iNTERACTIVE $ tcRnGetInfo' hsc_env name tcRnGetInfo' :: HscEnv -> Name -> TcRn (TyThing, Fixity, [Instance]) tcRnGetInfo' hsc_env name = let ictxt = hsc_IC hsc_env in setInteractiveContext hsc_env ictxt $ do -- Load the interface for all unqualified types and classes -- That way we will find all the instance declarations -- (Packages have not orphan modules, and we assume that -- in the home package all relevant modules are loaded.) loadUnqualIfaces hsc_env ictxt thing <- tcRnLookupName' name fixity <- lookupFixityRn name ispecs <- lookupInsts thing return (thing, fixity, ispecs) lookupInsts :: TyThing -> TcM [Instance] lookupInsts (ATyCon tc) | Just cls <- tyConClass_maybe tc = do { inst_envs <- tcGetInstEnvs ; return (classInstances inst_envs cls) } | otherwise = do { (pkg_ie, home_ie) <- tcGetInstEnvs -- Load all instances for all classes that are -- in the type environment (which are all the ones -- we've seen in any interface file so far) ; return [ ispec -- Search all | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie , let dfun = instanceDFunId ispec , relevant dfun ] } where relevant df = tc_name `elemNameSet` orphNamesOfDFunHead (idType df) tc_name = tyConName tc lookupInsts _ = return [] loadUnqualIfaces :: HscEnv -> InteractiveContext -> TcM () -- Load the interface for everything that is in scope unqualified -- This is so that we can accurately report the instances for -- something loadUnqualIfaces hsc_env ictxt = initIfaceTcRn $ do mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods)) where this_pkg = thisPackage (hsc_dflags hsc_env) unqual_mods = filter ((/= this_pkg) . modulePackageId) [ nameModule name | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt), let name = gre_name gre, not (isInternalName name), isTcOcc (nameOccName name), -- Types and classes only unQualOK gre ] -- In scope unqualified doc = ptext (sLit "Need interface for module whose export(s) are in scope unqualified") \end{code} %************************************************************************ %* * Degugging output %* * %************************************************************************ \begin{code} rnDump :: SDoc -> TcRn () -- Dump, with a banner, if -ddump-rn rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) } tcDump :: TcGblEnv -> TcRn () tcDump env = do { dflags <- getDOpts ; -- Dump short output if -ddump-types or -ddump-tc when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags) (dumpTcRn short_dump) ; -- Dump bindings if -ddump-tc dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) } where short_dump = pprTcGblEnv env full_dump = pprLHsBinds (tcg_binds env) -- NB: foreign x-d's have undefined's in their types; -- hence can't show the tc_fords tcCoreDump :: ModGuts -> TcM () tcCoreDump mod_guts = do { dflags <- getDOpts ; when (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags) (dumpTcRn (pprModGuts mod_guts)) ; -- Dump bindings if -ddump-tc dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) } where full_dump = pprCoreBindings (mg_binds mod_guts) -- It's unpleasant having both pprModGuts and pprModDetails here pprTcGblEnv :: TcGblEnv -> SDoc pprTcGblEnv (TcGblEnv { tcg_type_env = type_env, tcg_insts = insts, tcg_fam_insts = fam_insts, tcg_rules = rules, tcg_vects = vects, tcg_imports = imports }) = vcat [ ppr_types insts type_env , ppr_tycons fam_insts type_env , ppr_insts insts , ppr_fam_insts fam_insts , vcat (map ppr rules) , vcat (map ppr vects) , ptext (sLit "Dependent modules:") <+> ppr (sortBy cmp_mp $ eltsUFM (imp_dep_mods imports)) , ptext (sLit "Dependent packages:") <+> ppr (sortBy stablePackageIdCmp $ imp_dep_pkgs imports)] where -- The two uses of sortBy are just to reduce unnecessary -- wobbling in testsuite output cmp_mp (mod_name1, is_boot1) (mod_name2, is_boot2) = (mod_name1 `stableModuleNameCmp` mod_name2) `thenCmp` (is_boot1 `compare` is_boot2) pprModGuts :: ModGuts -> SDoc pprModGuts (ModGuts { mg_tcs = tcs , mg_rules = rules }) = vcat [ ppr_types [] (mkTypeEnv (map ATyCon tcs)), ppr_rules rules ] ppr_types :: [Instance] -> TypeEnv -> SDoc ppr_types insts type_env = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids) where dfun_ids = map instanceDFunId insts ids = [id | id <- typeEnvIds type_env, want_sig id] want_sig id | opt_PprStyle_Debug = True | otherwise = isLocalId id && isExternalName (idName id) && not (id `elem` dfun_ids) -- isLocalId ignores data constructors, records selectors etc. -- The isExternalName ignores local dictionary and method bindings -- that the type checker has invented. Top-level user-defined things -- have External names. ppr_tycons :: [FamInst] -> TypeEnv -> SDoc ppr_tycons fam_insts type_env = vcat [ text "TYPE CONSTRUCTORS" , nest 2 (ppr_tydecls tycons) , text "COERCION AXIOMS" , nest 2 (vcat (map pprCoAxiom (typeEnvCoAxioms type_env))) ] where fi_tycons = map famInstTyCon fam_insts tycons = [tycon | tycon <- typeEnvTyCons type_env, want_tycon tycon] want_tycon tycon | opt_PprStyle_Debug = True | otherwise = not (isImplicitTyCon tycon) && isExternalName (tyConName tycon) && not (tycon `elem` fi_tycons) ppr_insts :: [Instance] -> SDoc ppr_insts [] = empty ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs) ppr_fam_insts :: [FamInst] -> SDoc ppr_fam_insts [] = empty ppr_fam_insts fam_insts = text "FAMILY INSTANCES" $$ nest 2 (pprFamInsts fam_insts) ppr_sigs :: [Var] -> SDoc ppr_sigs ids -- Print type signatures; sort by OccName = vcat (map ppr_sig (sortLe le_sig ids)) where le_sig id1 id2 = getOccName id1 <= getOccName id2 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id)) ppr_tydecls :: [TyCon] -> SDoc ppr_tydecls tycons -- Print type constructor info; sort by OccName = vcat (map ppr_tycon (sortLe le_sig tycons)) where le_sig tycon1 tycon2 = getOccName tycon1 <= getOccName tycon2 ppr_tycon tycon = ppr (tyThingToIfaceDecl (ATyCon tycon)) ppr_rules :: [CoreRule] -> SDoc ppr_rules [] = empty ppr_rules rs = vcat [ptext (sLit "{-# RULES"), nest 2 (pprRules rs), ptext (sLit "#-}")] \end{code}