X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcModule.lhs;h=50343ef502de6aff26a0489593709f27a07db984;hb=20d1c20c49feae6b862c87504bbd9b8c483044f3;hp=d10c84b307d1586a701c9681ba36a65162a105a2;hpb=ff755dd9a0a0ad2f106c323852553ea247f16141;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcModule.lhs b/ghc/compiler/typecheck/TcModule.lhs index d10c84b..50343ef 100644 --- a/ghc/compiler/typecheck/TcModule.lhs +++ b/ghc/compiler/typecheck/TcModule.lhs @@ -5,63 +5,63 @@ \begin{code} module TcModule ( - typecheckModule, - TcResults(..) + typecheckModule, typecheckIface, typecheckExpr, TcResults(..) ) where #include "HsVersions.h" -import CmdLineOpts ( opt_D_dump_tc, opt_D_dump_types, opt_PprStyle_Debug ) -import HsSyn ( HsModule(..), HsBinds(..), MonoBinds(..), HsDecl(..) ) +import CmdLineOpts ( DynFlag(..), DynFlags, opt_PprStyle_Debug ) +import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..), HsExpr(..), + isIfaceRuleDecl, nullBinds, andMonoBindList + ) import HsTypes ( toHsType ) -import RnHsSyn ( RenamedHsModule ) -import TcHsSyn ( TcMonoBinds, TypecheckedMonoBinds, +import PrelNames ( SyntaxMap, mAIN_Name, mainName, ioTyConName, printName ) +import RnHsSyn ( RenamedHsBinds, RenamedHsDecl, RenamedHsExpr ) +import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr, TypecheckedForeignDecl, TypecheckedRuleDecl, - zonkTopBinds, zonkForeignExports, zonkRules + zonkTopBinds, zonkForeignExports, zonkRules, mkHsLet, + zonkExpr ) + import TcMonad -import Inst ( Inst, emptyLIE, plusLIE ) -import TcBinds ( tcTopBindsAndThen ) -import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds ) -import TcDefaults ( tcDefaults ) -import TcEnv ( tcExtendGlobalValEnv, tcExtendTypeEnv, - getEnvTyCons, getEnvClasses, tcLookupValueByKeyMaybe, - explicitLookupValueByKey, tcSetValueEnv, tcSetInstEnv, - initEnv, - ValueEnv, TcTyThing(..) +import TcType ( newTyVarTy, zonkTcType, tcInstType ) +import TcUnify ( unifyTauTy ) +import Inst ( plusLIE ) +import VarSet ( varSetElems ) +import TcBinds ( tcTopBinds ) +import TcClassDcl ( tcClassDecls2 ) +import TcDefaults ( tcDefaults, defaultDefaultTys ) +import TcExpr ( tcMonoExpr ) +import TcEnv ( TcEnv, RecTcEnv, InstInfo, tcExtendGlobalValEnv, tcLookup_maybe, + isLocalThing, tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv, + TcTyThing(..), tcLookupTyCon ) -import TcRules ( tcRules ) +import TcRules ( tcIfaceRules, tcSourceRules ) import TcForeign ( tcForeignImports, tcForeignExports ) import TcIfaceSig ( tcInterfaceSigs ) import TcInstDcls ( tcInstDecls1, tcInstDecls2 ) -import TcInstUtil ( buildInstanceEnv, InstInfo ) -import TcSimplify ( tcSimplifyTop ) +import TcSimplify ( tcSimplifyTop, tcSimplifyInfer ) import TcTyClsDecls ( tcTyAndClassDecls ) -import TcTyDecls ( mkImplicitDataBinds ) -import TcType ( TcType, typeToTcType, - TcKind, kindToTcKind, - newTyVarTy - ) -import RnMonad ( RnNameSupply, FixityEnv ) -import Bag ( isEmptyBag ) -import ErrUtils ( Message, printErrorsAndWarnings, dumpIfSet ) -import Id ( Id, idType, idName ) -import Module ( pprModuleName ) -import OccName ( isSysOcc ) -import Name ( Name, nameUnique, nameOccName, isLocallyDefined, - toRdrName, nameEnvElts, NamedThing(..) - ) -import TyCon ( TyCon, tyConKind ) -import Class ( Class, classSelIds, classTyCon ) -import PrelInfo ( mAIN_Name ) -import Unique ( Unique, mainKey ) -import UniqSupply ( UniqSupply ) -import Maybes ( maybeToBool ) +import CoreUnfold ( unfoldingTemplate, hasUnfolding ) +import Type ( funResultTy, splitForAllTys, mkForAllTys, mkFunTys, + liftedTypeKind, openTypeKind, mkTyConApp, tyVarsOfType, tidyType ) +import ErrUtils ( printErrorsAndWarnings, errorsFound, dumpIfSet_dyn, showPass ) +import Id ( idType, idName, isLocalId, idUnfolding ) +import Module ( Module, isHomeModule, moduleName ) +import Name ( Name, toRdrName, isGlobalName ) +import Name ( nameEnvElts, lookupNameEnv ) +import TyCon ( tyConGenInfo ) import Util -import Bag ( Bag, isEmptyBag ) +import BasicTypes ( EP(..), Fixity ) import Outputable +import HscTypes ( PersistentCompilerState(..), HomeSymbolTable, + PackageTypeEnv, ModIface(..), + TypeEnv, extendTypeEnvList, + TyThing(..), implicitTyThingIds, + mkTypeEnv + ) \end{code} Outside-world interface: @@ -70,170 +70,220 @@ Outside-world interface: -- Convenient type synonyms first: data TcResults = TcResults { - tc_binds :: TypecheckedMonoBinds, - tc_tycons :: [TyCon], - tc_classes :: [Class], - tc_insts :: Bag InstInfo, -- Instance declaration information + -- All these fields have info *just for this module* + tc_env :: TypeEnv, -- The top level TypeEnv + tc_binds :: TypecheckedMonoBinds, -- Bindings tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports. - tc_rules :: [TypecheckedRuleDecl], -- Transformation rules - tc_env :: ValueEnv + tc_rules :: [TypecheckedRuleDecl] -- Transformation rules } --------------- typecheckModule - :: UniqSupply - -> RnNameSupply - -> FixityEnv - -> RenamedHsModule - -> IO (Maybe TcResults) - -typecheckModule us rn_name_supply fixity_env mod - = initTc us initEnv (tcModule rn_name_supply fixity_env mod) >>= \ (maybe_result, warns, errs) -> - - printErrorsAndWarnings errs warns >> - - (case maybe_result of - Nothing -> return () - Just results -> dumpIfSet opt_D_dump_types "Type signatures" (dump_sigs results) >> - dumpIfSet opt_D_dump_tc "Typechecked" (dump_tc results) - ) >> - - return (if isEmptyBag errs then - maybe_result - else - Nothing) + :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> ModIface -- Iface for this module (just module & fixities) + -> PrintUnqualified -- For error printing + -> (SyntaxMap, [RenamedHsDecl]) + -> IO (Maybe (PersistentCompilerState, TcResults)) + -- The new PCS is Augmented with imported information, + -- (but not stuff from this module) + + +typecheckModule dflags pcs hst mod_iface unqual (syn_map, decls) + = do { maybe_tc_result <- typecheck dflags syn_map pcs hst unqual $ + tcModule pcs hst get_fixity this_mod decls + ; printTcDump dflags maybe_tc_result + ; return maybe_tc_result } + where + this_mod = mi_module mod_iface + fixity_env = mi_fixities mod_iface -dump_tc results - = ppr (tc_binds results) $$ pp_rules (tc_rules results) + get_fixity :: Name -> Maybe Fixity + get_fixity nm = lookupNameEnv fixity_env nm -dump_sigs results -- Print type signatures - = -- Convert to HsType so that we get source-language style printing - -- And sort by RdrName - vcat $ map ppr_sig $ sortLt lt_sig $ - [(toRdrName id, toHsType (idType id)) | id <- nameEnvElts (tc_env results), - want_sig id - ] +--------------- +typecheckIface + :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> ModIface -- Iface for this module (just module & fixities) + -> (SyntaxMap, [RenamedHsDecl]) + -> IO (Maybe (PersistentCompilerState, TypeEnv, [TypecheckedRuleDecl])) + -- The new PCS is Augmented with imported information, + -- (but not stuff from this module). + -- The TcResults returned contains only the environment + -- and rules. + + +typecheckIface dflags pcs hst mod_iface (syn_map, decls) + = do { maybe_tc_stuff <- typecheck dflags syn_map pcs hst alwaysQualify $ + tcIfaceImports pcs hst get_fixity this_mod decls + ; printIfaceDump dflags maybe_tc_stuff + ; return maybe_tc_stuff } where - lt_sig (n1,_) (n2,_) = n1 < n2 - ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t + this_mod = mi_module mod_iface + fixity_env = mi_fixities mod_iface + + get_fixity :: Name -> Maybe Fixity + get_fixity nm = lookupNameEnv fixity_env nm + + tcIfaceImports pcs hst get_fixity this_mod decls + = fixTc (\ ~(unf_env, _, _, _, _) -> + tcImports unf_env pcs hst get_fixity this_mod decls + ) `thenTc` \ (env, new_pcs, local_inst_info, + deriv_binds, local_rules) -> + ASSERT(nullBinds deriv_binds) + let + local_things = filter (isLocalThing this_mod) + (nameEnvElts (getTcGEnv env)) + local_type_env :: TypeEnv + local_type_env = mkTypeEnv local_things + in + + -- throw away local_inst_info + returnTc (new_pcs, local_type_env, local_rules) - want_sig id | opt_PprStyle_Debug = True - | otherwise = isLocallyDefined n && not (isSysOcc (nameOccName n)) - where - n = idName id +--------------- +typecheckExpr :: DynFlags + -> Bool -- True <=> wrap in 'print' to get a result of IO type + -> PersistentCompilerState + -> HomeSymbolTable + -> PrintUnqualified -- For error printing + -> Module + -> (SyntaxMap, + RenamedHsExpr, -- The expression itself + [RenamedHsDecl]) -- Plus extra decls it sucked in from interface files + -> IO (Maybe (PersistentCompilerState, TypecheckedHsExpr, TcType)) + +typecheckExpr dflags wrap_io pcs hst unqual this_mod (syn_map, expr, decls) + = typecheck dflags syn_map pcs hst unqual $ + + -- use the default default settings, i.e. [Integer, Double] + tcSetDefaultTys defaultDefaultTys $ + + -- Typecheck the extra declarations + fixTc (\ ~(unf_env, _, _, _, _) -> + tcImports unf_env pcs hst get_fixity this_mod decls + ) `thenTc` \ (env, new_pcs, local_inst_info, deriv_binds, local_rules) -> + ASSERT( null local_inst_info && nullBinds deriv_binds && null local_rules ) + + -- Now typecheck the expression + tcSetEnv env $ + tc_expr expr `thenTc` \ (expr', expr_ty) -> + zonkExpr expr' `thenNF_Tc` \ zonked_expr -> + zonkTcType expr_ty `thenNF_Tc` \ zonked_ty -> + ioToTc (dumpIfSet_dyn dflags + Opt_D_dump_tc "Typechecked" (ppr zonked_expr)) `thenNF_Tc_` + returnTc (new_pcs, zonked_expr, zonked_ty) -pp_rules [] = empty -pp_rules rs = vcat [ptext SLIT("{-# RULES"), - nest 4 (vcat (map ppr rs)), - ptext SLIT("#-}")] + where + get_fixity :: Name -> Maybe Fixity + get_fixity n = pprPanic "typecheckExpr" (ppr n) + + smpl_doc = ptext SLIT("main expression") + + -- Typecheck it, wrapping in 'print' if necessary to + -- get a result of type IO t. Returns the result type + -- that is free in the result type + tc_expr e + | wrap_io = tryTc_ (tc_io_expr (HsApp (HsVar printName) e)) -- Recovery case + (tc_io_expr e) -- Main case + | otherwise = newTyVarTy openTypeKind `thenTc` \ ty -> + tcMonoExpr e ty `thenTc` \ (e', lie) -> + tcSimplifyInfer smpl_doc (varSetElems (tyVarsOfType ty)) lie + `thenTc` \ (qtvs, lie_free, dict_binds, dict_ids) -> + tcSimplifyTop lie_free `thenTc` \ const_binds -> + let all_expr = mkHsLet const_binds $ + TyLam qtvs $ + DictLam dict_ids $ + mkHsLet dict_binds $ + e' + all_expr_ty = mkForAllTys qtvs $ + mkFunTys (map idType dict_ids) $ + ty + in + returnTc (all_expr, all_expr_ty) + where + tc_io_expr e = newTyVarTy openTypeKind `thenTc` \ ty -> + tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon -> + let + res_ty = mkTyConApp ioTyCon [ty] + in + tcMonoExpr e res_ty `thenTc` \ (e', lie) -> + tcSimplifyTop lie `thenTc` \ const_binds -> + let all_expr = mkHsLet const_binds e' in + returnTc (all_expr, res_ty) + +--------------- +typecheck :: DynFlags + -> SyntaxMap + -> PersistentCompilerState + -> HomeSymbolTable + -> PrintUnqualified -- For error printing + -> TcM r + -> IO (Maybe r) + +typecheck dflags syn_map pcs hst unqual thing_inside + = do { showPass dflags "Typechecker"; + ; env <- initTcEnv syn_map hst (pcs_PTE pcs) + + ; (maybe_tc_result, errs) <- initTc dflags env thing_inside + + ; printErrorsAndWarnings unqual errs + + ; if errorsFound errs then + return Nothing + else + return maybe_tc_result + } \end{code} The internal monster: \begin{code} -tcModule :: RnNameSupply -- for renaming derivings - -> FixityEnv -- needed for Show/Read derivings. - -> RenamedHsModule -- input - -> TcM s TcResults -- output - -tcModule rn_name_supply fixities - (HsModule mod_name _ _ _ decls _ src_loc) - = tcAddSrcLoc src_loc $ -- record where we're starting - - fixTc (\ ~(unf_env ,_) -> - -- unf_env is used for type-checking interface pragmas - -- which is done lazily [ie failure just drops the pragma - -- without having any global-failure effect]. - -- - -- unf_env is also used to get the pragam info - -- for imported dfuns and default methods - - -- Type-check the type and class decls - tcTyAndClassDecls unf_env decls `thenTc` \ env -> - - -- Typecheck the instance decls, includes deriving - tcSetEnv env $ - - tcInstDecls1 unf_env decls - mod_name fixities - rn_name_supply `thenTc` \ (inst_info, deriv_binds) -> - - buildInstanceEnv inst_info `thenNF_Tc` \ inst_env -> - - tcSetInstEnv inst_env $ - let - tycons = getEnvTyCons env - classes = getEnvClasses env - local_tycons = filter isLocallyDefined tycons - local_classes = filter isLocallyDefined classes - in - - -- Default declarations - tcDefaults decls `thenTc` \ defaulting_tys -> - tcSetDefaultTys defaulting_tys $ - - -- Extend the TyCon envt with the tycons corresponding to - -- the classes. - -- They are mentioned in types in interface files. - tcExtendTypeEnv [ (getName tycon, (kindToTcKind (tyConKind tycon), ADataTyCon tycon)) - | clas <- classes, - let tycon = classTyCon clas - ] $ - - -- Interface type signatures - -- We tie a knot so that the Ids read out of interfaces are in scope - -- when we read their pragmas. - -- What we rely on is that pragmas are typechecked lazily; if - -- any type errors are found (ie there's an inconsistency) - -- we silently discard the pragma - -- We must do this before mkImplicitDataBinds (which comes next), since - -- the latter looks up unpackCStringId, for example, which is usually - -- imported - tcInterfaceSigs unf_env decls `thenTc` \ sig_ids -> - tcExtendGlobalValEnv sig_ids $ - - -- Create any necessary record selector Ids and their bindings - -- "Necessary" includes data and newtype declarations - -- We don't create bindings for dictionary constructors; - -- they are always fully applied, and the bindings are just there - -- to support partial applications - mkImplicitDataBinds tycons `thenTc` \ (data_ids, imp_data_binds) -> - mkImplicitClassBinds classes `thenNF_Tc` \ (cls_ids, imp_cls_binds) -> - - -- Extend the global value environment with - -- (a) constructors - -- (b) record selectors - -- (c) class op selectors - -- (d) default-method ids... where? I can't see where these are - -- put into the envt, and I'm worried that the zonking phase - -- will find they aren't there and complain. - tcExtendGlobalValEnv data_ids $ - tcExtendGlobalValEnv cls_ids $ - - -- foreign import declarations next. - tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) -> +tcModule :: PersistentCompilerState + -> HomeSymbolTable + -> (Name -> Maybe Fixity) + -> Module + -> [RenamedHsDecl] + -> TcM (PersistentCompilerState, TcResults) + +tcModule pcs hst get_fixity this_mod decls + = fixTc (\ ~(unf_env, _, _) -> + -- Loop back the final environment, including the fully zonkec + -- versions of bindings from this module. In the presence of mutual + -- recursion, interface type signatures may mention variables defined + -- in this module, which is why the knot is so big + + -- Type-check the type and class decls, and all imported decls + tcImports unf_env pcs hst get_fixity this_mod decls + `thenTc` \ (env, new_pcs, local_insts, deriv_binds, local_rules) -> + + tcSetEnv env $ + + -- Foreign import declarations next + traceTc (text "Tc4") `thenNF_Tc_` + tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) -> tcExtendGlobalValEnv fo_ids $ - + + -- Default declarations + tcDefaults decls `thenTc` \ defaulting_tys -> + tcSetDefaultTys defaulting_tys $ + -- Value declarations next. -- We also typecheck any extra binds that came out of the "deriving" process - tcTopBindsAndThen - (\ is_rec binds1 (binds2, thing) -> (binds1 `AndMonoBinds` binds2, thing)) - (get_val_decls decls `ThenBinds` deriv_binds) - ( tcGetEnv `thenNF_Tc` \ env -> - tcGetUnique `thenNF_Tc` \ uniq -> - returnTc ((EmptyMonoBinds, env), emptyLIE) - ) `thenTc` \ ((val_binds, final_env), lie_valdecls) -> - tcSetEnv final_env $ - - -- foreign export declarations next. - tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) -> - - -- Second pass over class and instance declarations, - -- to compile the bindings themselves. - tcInstDecls2 inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) -> - tcClassDecls2 decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) -> - tcRules decls `thenNF_Tc` \ (lie_rules, rules) -> - - + traceTc (text "Default types" <+> ppr defaulting_tys) `thenNF_Tc_` + traceTc (text "Tc5") `thenNF_Tc_` + tcTopBinds (val_binds `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) -> + + -- Second pass over class and instance declarations, + -- plus rules and foreign exports, to generate bindings + tcSetEnv env $ + tcInstDecls2 local_insts `thenNF_Tc` \ (lie_instdecls, inst_binds) -> + tcClassDecls2 this_mod tycl_decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) -> + tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) -> + tcSourceRules source_rules `thenNF_Tc` \ (lie_rules, more_local_rules) -> + -- Deal with constant or ambiguous InstIds. How could -- there be ambiguous ones? They can only arise if a -- top-level decl falls under the monomorphism @@ -241,59 +291,282 @@ tcModule rn_name_supply fixities -- type. (Usually, ambiguous type variables are resolved -- during the generalisation step.) let - lie_alldecls = lie_valdecls `plusLIE` + lie_alldecls = lie_valdecls `plusLIE` lie_instdecls `plusLIE` lie_clasdecls `plusLIE` lie_fodecls `plusLIE` lie_rules in + traceTc (text "Tc6") `thenNF_Tc_` tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds -> - - -- Check that Main defines main - (if mod_name == mAIN_Name then - tcLookupValueByKeyMaybe mainKey `thenNF_Tc` \ maybe_main -> - checkTc (maybeToBool maybe_main) noMainErr - else - returnTc () - ) `thenTc_` - + + -- CHECK THAT main IS DEFINED WITH RIGHT TYPE, IF REQUIRED + tcCheckMain this_mod `thenTc_` + -- Backsubstitution. This must be done last. -- Even tcSimplifyTop may do some unification. let - all_binds = imp_data_binds `AndMonoBinds` - imp_cls_binds `AndMonoBinds` - val_binds `AndMonoBinds` - inst_binds `AndMonoBinds` - cls_dm_binds `AndMonoBinds` - const_inst_binds `AndMonoBinds` - foe_binds + all_binds = val_binds `AndMonoBinds` + inst_binds `AndMonoBinds` + cls_dm_binds `AndMonoBinds` + const_inst_binds `AndMonoBinds` + foe_binds in - zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', really_final_env) -> - tcSetValueEnv really_final_env $ - zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' -> - zonkRules rules `thenNF_Tc` \ rules' -> - - returnTc (really_final_env, - (TcResults { tc_binds = all_binds', - tc_tycons = local_tycons, - tc_classes = local_classes, - tc_insts = inst_info, - tc_fords = foi_decls ++ foe_decls', - tc_rules = rules', - tc_env = really_final_env - })) - - -- End of outer fix loop - ) `thenTc` \ (final_env, stuff) -> - returnTc stuff - -get_val_decls decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls] + traceTc (text "Tc7") `thenNF_Tc_` + zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) -> + tcSetEnv final_env $ + -- zonkTopBinds puts all the top-level Ids into the tcGEnv + traceTc (text "Tc8") `thenNF_Tc_` + zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' -> + traceTc (text "Tc9") `thenNF_Tc_` + zonkRules more_local_rules `thenNF_Tc` \ more_local_rules' -> + + + let local_things = filter (isLocalThing this_mod) (nameEnvElts (getTcGEnv final_env)) + + -- Create any necessary "implicit" bindings (data constructors etc) + -- Should we create bindings for dictionary constructors? + -- They are always fully applied, and the bindings are just there + -- to support partial applications. But it's easier to let them through. + implicit_binds = andMonoBindList [ CoreMonoBind id (unfoldingTemplate unf) + | id <- implicitTyThingIds local_things + , let unf = idUnfolding id + , hasUnfolding unf + ] + + local_type_env :: TypeEnv + local_type_env = mkTypeEnv local_things + + all_local_rules = local_rules ++ more_local_rules' + in + traceTc (text "Tc10") `thenNF_Tc_` + returnTc (final_env, + new_pcs, + TcResults { tc_env = local_type_env, + tc_binds = implicit_binds `AndMonoBinds` all_binds', + tc_fords = foi_decls ++ foe_decls', + tc_rules = all_local_rules + } + ) + ) `thenTc` \ (_, pcs, tc_result) -> + returnTc (pcs, tc_result) + where + tycl_decls = [d | TyClD d <- decls] + val_binds = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls] + source_rules = [d | RuleD d <- decls, not (isIfaceRuleDecl d)] \end{code} \begin{code} -noMainErr - = hsep [ptext SLIT("Module"), quotes (pprModuleName mAIN_Name), - ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))] +tcImports :: RecTcEnv + -> PersistentCompilerState + -> HomeSymbolTable + -> (Name -> Maybe Fixity) + -> Module + -> [RenamedHsDecl] + -> TcM (TcEnv, PersistentCompilerState, [InstInfo], + RenamedHsBinds, [TypecheckedRuleDecl]) + +-- tcImports is a slight mis-nomer. +-- It deals with everythign that could be an import: +-- type and class decls +-- interface signatures +-- instance decls +-- rule decls +-- These can occur in source code too, of course + +tcImports unf_env pcs hst get_fixity this_mod decls + -- (unf_env :: RecTcEnv) is used for type-checking interface pragmas + -- which is done lazily [ie failure just drops the pragma + -- without having any global-failure effect]. + -- + -- unf_env is also used to get the pragama info + -- for imported dfuns and default methods + + = checkNoErrsTc $ + -- tcImports recovers internally, but if anything gave rise to + -- an error we'd better stop now, to avoid a cascade + + traceTc (text "Tc1") `thenNF_Tc_` + tcTyAndClassDecls unf_env tycl_decls `thenTc` \ env -> + tcSetEnv env $ + + -- Typecheck the instance decls, includes deriving + traceTc (text "Tc2") `thenNF_Tc_` + tcInstDecls1 (pcs_insts pcs) (pcs_PRS pcs) + hst unf_env get_fixity this_mod + decls `thenTc` \ (new_pcs_insts, inst_env, local_insts, deriv_binds) -> + tcSetInstEnv inst_env $ + + -- Interface type signatures + -- We tie a knot so that the Ids read out of interfaces are in scope + -- when we read their pragmas. + -- What we rely on is that pragmas are typechecked lazily; if + -- any type errors are found (ie there's an inconsistency) + -- we silently discard the pragma + traceTc (text "Tc3") `thenNF_Tc_` + tcInterfaceSigs unf_env tycl_decls `thenTc` \ sig_ids -> + tcExtendGlobalValEnv sig_ids $ + + + tcIfaceRules (pcs_rules pcs) this_mod iface_rules `thenNF_Tc` \ (new_pcs_rules, local_rules) -> + -- When relinking this module from its interface-file decls + -- we'll have IfaceRules that are in fact local to this module + -- That's the reason we we get any local_rules out here + + tcGetEnv `thenTc` \ unf_env -> + let + all_things = nameEnvElts (getTcGEnv unf_env) + + -- sometimes we're compiling in the context of a package module + -- (on the GHCi command line, for example). In this case, we + -- want to treat everything we pulled in as an imported thing. + imported_things + | isHomeModule this_mod + = filter (not . isLocalThing this_mod) all_things + | otherwise + = all_things + + new_pte :: PackageTypeEnv + new_pte = extendTypeEnvList (pcs_PTE pcs) imported_things + + new_pcs :: PersistentCompilerState + new_pcs = pcs { pcs_PTE = new_pte, + pcs_insts = new_pcs_insts, + pcs_rules = new_pcs_rules + } + in + returnTc (unf_env, new_pcs, local_insts, deriv_binds, local_rules) + where + tycl_decls = [d | TyClD d <- decls] + iface_rules = [d | RuleD d <- decls, isIfaceRuleDecl d] +\end{code} + +%************************************************************************ +%* * +\subsection{Checking the type of main} +%* * +%************************************************************************ + +We must check that in module Main, + a) main is defined + b) main :: forall a1...an. IO t, for some type t + +If we have + main = error "Urk" +then the type of main will be + main :: forall a. a +and that should pass the test too. + +So we just instantiate the type and unify with IO t, and declare +victory if doing so succeeds. + +\begin{code} +tcCheckMain :: Module -> TcM () +tcCheckMain this_mod + | not (moduleName this_mod == mAIN_Name ) + = returnTc () + + | otherwise + = -- First unify the main_id with IO t, for any old t + tcLookup_maybe mainName `thenNF_Tc` \ maybe_thing -> + case maybe_thing of + Just (ATcId main_id) -> check_main_ty (idType main_id) + other -> addErrTc noMainErr + where + check_main_ty main_ty + = tcInstType main_ty `thenNF_Tc` \ (tvs, theta, main_tau) -> + newTyVarTy liftedTypeKind `thenNF_Tc` \ arg_ty -> + tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon -> + tcAddErrCtxtM (mainTypeCtxt main_ty) $ + if not (null theta) then + failWithTc empty -- Context has the error message + else + unifyTauTy main_tau (mkTyConApp ioTyCon [arg_ty]) + +mainTypeCtxt main_ty tidy_env + = zonkTcType main_ty `thenNF_Tc` \ main_ty' -> + returnNF_Tc (tidy_env, ptext SLIT("`main' has the illegal type") <+> + quotes (ppr (tidyType tidy_env main_ty'))) + +noMainErr = hsep [ptext SLIT("Module") <+> quotes (ppr mAIN_Name), + ptext SLIT("must include a definition for") <+> quotes (ptext SLIT("main"))] \end{code} + +%************************************************************************ +%* * +\subsection{Dumping output} +%* * +%************************************************************************ + +\begin{code} +printTcDump dflags Nothing = return () +printTcDump dflags (Just (_, results)) + = do dumpIfSet_dyn dflags Opt_D_dump_types + "Type signatures" (dump_sigs (tc_env results)) + dumpIfSet_dyn dflags Opt_D_dump_tc + "Typechecked" (dump_tc results) + +printIfaceDump dflags Nothing = return () +printIfaceDump dflags (Just (_, env, rules)) + = do dumpIfSet_dyn dflags Opt_D_dump_types + "Type signatures" (dump_sigs env) + dumpIfSet_dyn dflags Opt_D_dump_tc + "Typechecked" (dump_iface env rules) + +dump_tc results + = vcat [ppr (tc_binds results), + pp_rules (tc_rules results), + ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)] + ] + +dump_iface env rules + = vcat [pp_rules rules, + ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts env] + ] + +dump_sigs env -- Print type signatures + = -- Convert to HsType so that we get source-language style printing + -- And sort by RdrName + vcat $ map ppr_sig $ sortLt lt_sig $ + [ (toRdrName id, toHsType (idType id)) + | AnId id <- nameEnvElts env, + want_sig id + ] + where + lt_sig (n1,_) (n2,_) = n1 < n2 + ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t + + want_sig id | opt_PprStyle_Debug = True + | otherwise = isLocalId id && isGlobalName (idName id) + -- isLocalId ignores data constructors, records selectors etc + -- The isGlobalName ignores local dictionary and method bindings + -- that the type checker has invented. User-defined things have + -- Global names. + +ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"), + vcat (map ppr_gen_tycon tcs), + ptext SLIT("#-}") + ] + +-- x&y are now Id's, not CoreExpr's +ppr_gen_tycon tycon + | Just ep <- tyConGenInfo tycon + = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep) + + | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable") + +ppr_ep (EP from to) + = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau), + ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)), + ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to)) + ] + where + (_,from_tau) = splitForAllTys (idType from) + +pp_rules [] = empty +pp_rules rs = vcat [ptext SLIT("{-# RULES"), + nest 4 (vcat (map ppr rs)), + ptext SLIT("#-}")] +\end{code}