X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcModule.lhs;h=9baf81bb40e153147f346f4a786feee996c309ec;hb=979947f545d70c63edb7ca96f6e47008ac90e3bf;hp=631167b3acf619c20f5e5d84eec12f89d28dc2a7;hpb=f8456d1ac4860a6718cca8210682e4516345baf7;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcModule.lhs b/ghc/compiler/typecheck/TcModule.lhs index 631167b..9baf81b 100644 --- a/ghc/compiler/typecheck/TcModule.lhs +++ b/ghc/compiler/typecheck/TcModule.lhs @@ -5,382 +5,674 @@ \begin{code} module TcModule ( - typecheckModule, typecheckExpr, TcResults(..) + typecheckModule, typecheckIface, typecheckStmt, typecheckExpr, + typecheckExtraDecls, + TcResults(..) ) where #include "HsVersions.h" -import CmdLineOpts ( DynFlag(..), DynFlags, opt_PprStyle_Debug ) +import CmdLineOpts ( DynFlag(..), DynFlags, dopt ) import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..), HsExpr(..), - isIfaceRuleDecl, nullBinds, andMonoBindList + Stmt(..), InPat(..), HsMatchContext(..), HsDoContext(..), RuleDecl(..), + isSourceInstDecl, mkSimpleMatch, placeHolderType ) -import HsTypes ( toHsType ) -import PrelNames ( mAIN_Name, mainName, ioTyConName, printName ) -import RnHsSyn ( RenamedHsBinds, RenamedHsDecl, RenamedHsExpr ) +import PrelNames ( ioTyConName, printName, + returnIOName, bindIOName, failIOName, runMainName, + dollarMainName, itName + ) +import MkId ( unsafeCoerceId ) +import RnHsSyn ( RenamedHsDecl, RenamedStmt, RenamedHsExpr, + RenamedRuleDecl, RenamedTyClDecl, RenamedInstDecl ) import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr, TypecheckedForeignDecl, TypecheckedRuleDecl, zonkTopBinds, zonkForeignExports, zonkRules, mkHsLet, - zonkExpr + zonkExpr, zonkIdBndr ) - +import Rename ( RnResult(..) ) +import MkIface ( pprModDetails ) +import TcExpr ( tcMonoExpr ) import TcMonad -import TcType ( newTyVarTy, zonkTcType, tcInstType ) -import TcUnify ( unifyTauTy ) -import Inst ( plusLIE ) -import VarSet ( varSetElems ) +import TcMType ( newTyVarTy, zonkTcType ) +import TcType ( Type, liftedTypeKind, openTypeKind, + tyVarsOfType, tcFunResultTy, + mkForAllTys, mkFunTys, mkTyConApp, tcSplitForAllTys, + tcSplitTyConApp_maybe, isUnitTy + ) +import TcMatches ( tcStmtsAndThen ) +import Inst ( LIE, emptyLIE, plusLIE ) import TcBinds ( tcTopBinds ) import TcClassDcl ( tcClassDecls2 ) import TcDefaults ( tcDefaults, defaultDefaultTys ) -import TcExpr ( tcMonoExpr ) -import TcEnv ( TcEnv, InstInfo, tcExtendGlobalValEnv, tcLookup_maybe, +import TcEnv ( TcEnv, RecTcEnv, InstInfo(iDFunId), tcExtendGlobalValEnv, isLocalThing, tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv, - TcTyThing(..), tcLookupTyCon + tcExtendGlobalEnv, tcExtendGlobalTypeEnv, + tcLookupGlobalId, tcLookupTyCon, + TyThing(..), tcLookupId ) import TcRules ( tcIfaceRules, tcSourceRules ) import TcForeign ( tcForeignImports, tcForeignExports ) import TcIfaceSig ( tcInterfaceSigs ) -import TcInstDcls ( tcInstDecls1, tcInstDecls2 ) +import TcInstDcls ( tcInstDecls1, tcIfaceInstDecls1, addInstDFuns, initInstEnv, tcInstDecls2 ) import TcSimplify ( tcSimplifyTop, tcSimplifyInfer ) import TcTyClsDecls ( tcTyAndClassDecls ) - -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 CoreUnfold ( unfoldingTemplate ) +import TysWiredIn ( mkListTy, unitTy ) +import ErrUtils ( printErrorsAndWarnings, errorsFound, + dumpIfSet_dyn, dumpIfSet_dyn_or, showPass ) +import Rules ( extendRuleBase ) +import Id ( Id, mkLocalId, idType, idUnfolding, setIdLocalExported ) +import Module ( Module ) +import Name ( Name, getName, getSrcLoc ) import TyCon ( tyConGenInfo ) -import Util -import BasicTypes ( EP(..), Fixity ) +import BasicTypes ( EP(..), RecFlag(..) ) +import SrcLoc ( noSrcLoc ) import Outputable +import IO ( stdout ) import HscTypes ( PersistentCompilerState(..), HomeSymbolTable, PackageTypeEnv, ModIface(..), - TypeEnv, extendTypeEnvList, - TyThing(..), implicitTyThingIds, + ModDetails(..), DFunId, + TypeEnv, extendTypeEnvList, typeEnvTyCons, typeEnvElts, mkTypeEnv ) -import IOExts +import List ( partition ) \end{code} -Outside-world interface: + +%************************************************************************ +%* * +\subsection{The stmt interface} +%* * +%************************************************************************ + \begin{code} +typecheckStmt + :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> TypeEnv -- The interactive context's type envt + -> PrintUnqualified -- For error printing + -> Module -- Is this really needed + -> [Name] -- Names bound by the Stmt (empty for expressions) + -> (RenamedStmt, -- The stmt itself + [RenamedHsDecl]) -- Plus extra decls it sucked in from interface files + -> IO (Maybe (PersistentCompilerState, + TypecheckedHsExpr, + [Id], + Type)) + -- The returned [Id] is the same as the input except for + -- ExprStmt, in which case the returned [Name] is [itName] + +typecheckStmt dflags pcs hst ic_type_env unqual this_mod names (stmt, iface_decls) + = typecheck dflags pcs hst unqual $ --- Convenient type synonyms first: -data TcResults - = TcResults { - -- 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 - } + -- use the default default settings, i.e. [Integer, Double] + tcSetDefaultTys defaultDefaultTys $ ---------------- -typecheckModule - :: DynFlags - -> PersistentCompilerState - -> HomeSymbolTable - -> ModIface -- Iface for this module - -> PrintUnqualified -- For error printing - -> [RenamedHsDecl] - -> IO (Maybe (PersistentCompilerState, TcResults)) - -- The new PCS is Augmented with imported information, - -- (but not stuff from this module) + -- Typecheck the extra declarations + tcExtraDecls pcs hst this_mod iface_decls `thenTc` \ (new_pcs, env) -> + tcSetEnv env $ + tcExtendGlobalTypeEnv ic_type_env $ -typecheckModule dflags pcs hst mod_iface unqual decls - = do { maybe_tc_result <- typecheck dflags pcs hst unqual $ - tcModule pcs hst get_fixity this_mod decls - ; printTcDump dflags maybe_tc_result - ; return maybe_tc_result } + -- The real work is done here + tcUserStmt names stmt `thenTc` \ (expr, bound_ids) -> + + traceTc (text "tcs 1") `thenNF_Tc_` + zonkExpr expr `thenNF_Tc` \ zonked_expr -> + mapNF_Tc zonkIdBndr bound_ids `thenNF_Tc` \ zonked_ids -> + + ioToTc (dumpIfSet_dyn dflags Opt_D_dump_tc "Bound Ids" (vcat (map ppr zonked_ids))) `thenNF_Tc_` + ioToTc (dumpIfSet_dyn dflags Opt_D_dump_tc "Typechecked" (ppr zonked_expr)) `thenNF_Tc_` + + returnTc (new_pcs, zonked_expr, zonked_ids, error "typecheckStmt: no type") +\end{code} + +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 >>= \ v -> return [v] + [NB: result not printed] bindings: [it] + + + expr (of non-IO type, + result showable) ==> let v = expr in print v >> return [v] + bindings: [it] + + expr (of non-IO type, + result not showable) ==> error + + +\begin{code} +tcUserStmt :: [Name] -> RenamedStmt -> TcM (TypecheckedHsExpr, [Id]) + +tcUserStmt names (ExprStmt expr _ loc) + = ASSERT( null names ) + tcGetUnique `thenNF_Tc` \ uniq -> + let + fresh_it = itName uniq + the_bind = FunMonoBind fresh_it False + [ mkSimpleMatch [] expr placeHolderType loc ] loc + in + tryTc_ (traceTc (text "tcs 1b") `thenNF_Tc_` + tc_stmts [fresh_it] [ + LetStmt (MonoBind the_bind [] NonRecursive), + ExprStmt (HsApp (HsVar printName) (HsVar fresh_it)) placeHolderType loc]) + ( traceTc (text "tcs 1a") `thenNF_Tc_` + tc_stmts [fresh_it] [BindStmt (VarPatIn fresh_it) expr loc]) + +tcUserStmt names stmt + = tc_stmts names [stmt] + + +tc_stmts names stmts + = tcLookupGlobalId returnIOName `thenNF_Tc` \ return_id -> + tcLookupGlobalId bindIOName `thenNF_Tc` \ bind_id -> + tcLookupGlobalId failIOName `thenNF_Tc` \ fail_id -> + tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon -> + newTyVarTy liftedTypeKind `thenNF_Tc` \ res_ty -> + let + io_ty = (\ ty -> mkTyConApp ioTyCon [ty], res_ty) + + -- mk_return builds the expression + -- returnIO @ [()] [coerce () x, .., coerce () z] + mk_return ids = HsApp (TyApp (HsVar return_id) [mkListTy unitTy]) + (ExplicitList unitTy (map mk_item ids)) + + mk_item id = HsApp (TyApp (HsVar unsafeCoerceId) [idType id, unitTy]) + (HsVar id) + in + + traceTc (text "tcs 2") `thenNF_Tc_` + tcStmtsAndThen combine (DoCtxt DoExpr) io_ty stmts ( + -- Look up the names right in the middle, + -- where they will all be in scope + mapNF_Tc tcLookupId names `thenNF_Tc` \ ids -> + returnTc ((ids, [ResultStmt (mk_return ids) noSrcLoc]), emptyLIE) + ) `thenTc` \ ((ids, tc_stmts), lie) -> + + -- Simplify the context right here, so that we fail + -- if there aren't enough instances. Notably, when we see + -- e + -- we use tryTc_ to try it <- e + -- and then let it = e + -- It's the simplify step that rejects the first. + + traceTc (text "tcs 3") `thenNF_Tc_` + tcSimplifyTop lie `thenTc` \ const_binds -> + traceTc (text "tcs 4") `thenNF_Tc_` + + returnTc (mkHsLet const_binds $ + HsDoOut DoExpr tc_stmts return_id bind_id fail_id + (mkTyConApp ioTyCon [mkListTy unitTy]) noSrcLoc, + ids) where - this_mod = mi_module mod_iface - fixity_env = mi_fixities mod_iface + combine stmt (ids, stmts) = (ids, stmt:stmts) +\end{code} - get_fixity :: Name -> Maybe Fixity - get_fixity nm = lookupNameEnv fixity_env nm +%************************************************************************ +%* * +\subsection{Typechecking an expression} +%* * +%************************************************************************ ---------------- +\begin{code} typecheckExpr :: DynFlags - -> Bool -- True <=> wrap in 'print' to get a result of IO type -> PersistentCompilerState -> HomeSymbolTable + -> TypeEnv -- The interactive context's type envt -> PrintUnqualified -- For error printing -> Module -> (RenamedHsExpr, -- The expression itself [RenamedHsDecl]) -- Plus extra decls it sucked in from interface files - -> IO (Maybe (PersistentCompilerState, TypecheckedHsExpr, TcType)) + -> IO (Maybe (PersistentCompilerState, + TypecheckedHsExpr, + [Id], -- always empty (matches typecheckStmt) + Type)) -typecheckExpr dflags wrap_io pcs hst unqual this_mod (expr, decls) +typecheckExpr dflags pcs hst ic_type_env unqual this_mod (expr, decls) = typecheck dflags pcs hst unqual $ -- use the default default settings, i.e. [Integer, Double] tcSetDefaultTys defaultDefaultTys $ - tcImports 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 ) - tcSetEnv env $ - tc_expr expr `thenTc` \ (expr', lie, expr_ty) -> - tcSimplifyInfer smpl_doc - (varSetElems (tyVarsOfType expr_ty)) lie `thenTc` \ (qtvs, lie_free, dict_binds, dict_ids) -> - tcSimplifyTop lie_free `thenTc` \ const_binds -> + -- Typecheck the extra declarations + tcExtraDecls pcs hst this_mod decls `thenTc` \ (new_pcs, env) -> + + -- Now typecheck the expression + tcSetEnv env $ + tcExtendGlobalTypeEnv ic_type_env $ + + newTyVarTy openTypeKind `thenTc` \ ty -> + tcMonoExpr expr ty `thenTc` \ (e', lie) -> + tcSimplifyInfer smpl_doc (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 $ - expr' - all_expr_ty = mkForAllTys qtvs (mkFunTys (map idType dict_ids) expr_ty) + TyLam qtvs $ + DictLam dict_ids $ + mkHsLet dict_binds $ + e' + + all_expr_ty = mkForAllTys qtvs $ + mkFunTys (map idType dict_ids) $ + ty in - zonkExpr all_expr `thenNF_Tc` \ zonked_expr -> - zonkTcType all_expr_ty `thenNF_Tc` \ zonked_ty -> + + zonkExpr all_expr `thenNF_Tc` \ zonked_expr -> + zonkTcType all_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) + returnTc (new_pcs, zonked_expr, [], zonked_ty) where - get_fixity :: Name -> Maybe Fixity - get_fixity n = pprPanic "typecheckExpr" (ppr n) - smpl_doc = ptext SLIT("main expression") +\end{code} - -- 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) -> - returnTc (e', lie, 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) -> - returnTc (e', lie, res_ty) - ---------------- -typecheck :: DynFlags - -> PersistentCompilerState - -> HomeSymbolTable - -> PrintUnqualified -- For error printing - -> TcM r - -> IO (Maybe r) - -typecheck dflags pcs hst unqual thing_inside - = do { showPass dflags "Typechecker"; - ; env <- initTcEnv hst (pcs_PTE pcs) +%************************************************************************ +%* * +\subsection{Typechecking extra declarations} +%* * +%************************************************************************ - ; (maybe_tc_result, errs) <- initTc dflags env thing_inside +\begin{code} +typecheckExtraDecls + :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> PrintUnqualified -- For error printing + -> Module -- Is this really needed + -> [RenamedHsDecl] -- extra decls sucked in from interface files + -> IO (Maybe PersistentCompilerState) + +typecheckExtraDecls dflags pcs hst unqual this_mod decls + = typecheck dflags pcs hst unqual $ + tcExtraDecls pcs hst this_mod decls `thenTc` \ (new_pcs, _) -> + returnTc new_pcs + +tcExtraDecls :: PersistentCompilerState + -> HomeSymbolTable + -> Module + -> [RenamedHsDecl] + -> TcM (PersistentCompilerState, TcEnv) + -- Returned environment includes instances + +tcExtraDecls pcs hst this_mod decls + = tcIfaceImports this_mod decls `thenTc` \ (env, all_things, dfuns, rules) -> + addInstDFuns (pcs_insts pcs) dfuns `thenNF_Tc` \ new_pcs_insts -> + let + new_pcs_pte = extendTypeEnvList (pcs_PTE pcs) all_things + new_pcs_rules = addIfaceRules (pcs_rules pcs) rules + + new_pcs :: PersistentCompilerState + new_pcs = pcs { pcs_PTE = new_pcs_pte, + pcs_insts = new_pcs_insts, + pcs_rules = new_pcs_rules + } + in + -- Initialise the instance environment + tcSetEnv env ( + initInstEnv new_pcs hst `thenNF_Tc` \ inst_env -> + tcSetInstEnv inst_env tcGetEnv + ) `thenNF_Tc` \ new_env -> + returnTc (new_pcs, new_env) +\end{code} - ; printErrorsAndWarnings unqual errs - ; if errorsFound errs then - return Nothing - else - return maybe_tc_result - } -\end{code} +%************************************************************************ +%* * +\subsection{Typechecking a module} +%* * +%************************************************************************ -The internal monster: \begin{code} +typecheckModule + :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> PrintUnqualified -- For error printing + -> RnResult + -> IO (Maybe (PersistentCompilerState, TcResults)) + -- The new PCS is Augmented with imported information, + -- (but not stuff from this module) + +data TcResults + = TcResults { + -- All these fields have info *just for this module* + tc_env :: TypeEnv, -- The top level TypeEnv + tc_insts :: [DFunId], -- Instances + tc_rules :: [TypecheckedRuleDecl], -- Transformation rules + tc_binds :: TypecheckedMonoBinds, -- Bindings + tc_fords :: [TypecheckedForeignDecl] -- Foreign import & exports. + } + + +typecheckModule dflags pcs hst unqual rn_result + = do { maybe_tc_result <- typecheck dflags pcs hst unqual $ + tcModule pcs hst rn_result + ; printTcDump dflags unqual maybe_tc_result + ; return maybe_tc_result } + tcModule :: PersistentCompilerState -> HomeSymbolTable - -> (Name -> Maybe Fixity) - -> Module - -> [RenamedHsDecl] + -> RnResult -> TcM (PersistentCompilerState, TcResults) -tcModule pcs hst get_fixity this_mod decls - = -- Type-check the type and class decls, and all imported decls - -- tcImports recovers internally, but if anything gave rise to - -- an error we'd better stop now, to avoid a cascade - checkNoErrsTc ( - tcImports pcs hst get_fixity this_mod decls - ) `thenTc` \ (env, new_pcs, local_inst_info, deriv_binds, local_rules) -> +tcModule pcs hst (RnResult { rr_decls = decls, rr_mod = this_mod, + rr_fixities = fix_env, rr_main = maybe_main_name }) + = fixTc (\ ~(unf_env, _, _) -> + -- Loop back the final environment, including the fully zonked + -- 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 - tcSetEnv env $ + -- Type-check the type and class decls, and all imported decls + tcImports unf_env pcs hst this_mod + tycl_decls iface_inst_decls iface_rule_decls `thenTc` \ (env1, new_pcs) -> + + tcSetEnv env1 $ + + -- Do the source-language instances, including derivings + initInstEnv new_pcs hst `thenNF_Tc` \ inst_env1 -> + tcInstDecls1 (pcs_PRS new_pcs) inst_env1 + fix_env this_mod + tycl_decls src_inst_decls `thenTc` \ (inst_env2, inst_info, deriv_binds) -> + tcSetInstEnv inst_env2 $ -- Foreign import declarations next --- traceTc (text "Tc4") `thenNF_Tc_` - tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) -> - tcExtendGlobalValEnv fo_ids $ + 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 $ + tcDefaults decls `thenTc` \ defaulting_tys -> + tcSetDefaultTys defaulting_tys $ -- Value declarations next. -- We also typecheck any extra binds that came out of the "deriving" process --- traceTc (text "Tc5") `thenNF_Tc_` - tcTopBinds (val_binds `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) -> - tcSetEnv env $ - - -- Foreign export declarations next --- traceTc (text "Tc6") `thenNF_Tc_` - tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) -> - - -- Second pass over class and instance declarations, - -- to compile the bindings themselves. - tcInstDecls2 local_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) -> - tcClassDecls2 this_mod tycl_decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) -> - 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 - -- restriction, and no subsequent decl instantiates its - -- type. (Usually, ambiguous type variables are resolved - -- during the generalisation step.) - let - lie_alldecls = lie_valdecls `plusLIE` - lie_instdecls `plusLIE` - lie_clasdecls `plusLIE` - lie_fodecls `plusLIE` - lie_rules - in - tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds -> + traceTc (text "Default types" <+> ppr defaulting_tys) `thenNF_Tc_` + traceTc (text "Tc5") `thenNF_Tc_` + tcTopBinds (val_binds `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env2), lie_valdecls) -> + + -- Second pass over class and instance declarations, + -- plus rules and foreign exports, to generate bindings + tcSetEnv env2 $ + traceTc (text "Tc6") `thenNF_Tc_` + traceTc (ppr (getTcGEnv env2)) `thenNF_Tc_` + tcClassDecls2 this_mod tycl_decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds, dm_ids) -> + tcExtendGlobalValEnv dm_ids $ + traceTc (text "Tc7") `thenNF_Tc_` + tcInstDecls2 inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) -> + traceTc (text "Tc8") `thenNF_Tc_` + tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) -> + traceTc (text "Tc9") `thenNF_Tc_` + tcSourceRules src_rule_decls `thenNF_Tc` \ (lie_rules, src_rules) -> + + -- CHECK THAT main IS DEFINED WITH RIGHT TYPE, IF REQUIRED + traceTc (text "Tc10") `thenNF_Tc_` + tcCheckMain maybe_main_name `thenTc` \ (main_bind, lie_main) -> + + -- 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 + -- restriction, and no subsequent decl instantiates its + -- type. (Usually, ambiguous type variables are resolved + -- during the generalisation step.) + -- + -- Note that we must do this *after* tcCheckMain, because of the + -- following bizarre case: + -- main = return () + -- Here, we infer main :: forall a. m a, where m is a free + -- type variable. tcCheckMain will unify it with IO, and that + -- must happen before tcSimplifyTop, since the latter will report + -- m as ambiguous + let + lie_alldecls = lie_valdecls `plusLIE` + lie_instdecls `plusLIE` + lie_clasdecls `plusLIE` + lie_fodecls `plusLIE` + lie_rules `plusLIE` + lie_main + in + tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds -> + traceTc (text "endsimpltop") `thenTc_` + + -- Backsubstitution. This must be done last. + -- Even tcSimplifyTop may do some unification. + let + all_binds = val_binds `AndMonoBinds` + inst_binds `AndMonoBinds` + cls_dm_binds `AndMonoBinds` + const_inst_binds `AndMonoBinds` + foe_binds `AndMonoBinds` + main_bind + in + 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 src_rules `thenNF_Tc` \ src_rules' -> + + + let src_things = filter (isLocalThing this_mod) (typeEnvElts (getTcGEnv final_env)) + -- This is horribly crude; the env might be jolly big + in + traceTc (text "Tc10") `thenNF_Tc_` + returnTc (final_env, + new_pcs, + TcResults { tc_env = mkTypeEnv src_things, + tc_insts = map iDFunId inst_info, + tc_binds = all_binds', + tc_fords = foi_decls ++ foe_decls', + tc_rules = src_rules' + } + ) + ) `thenTc` \ (_, pcs, tc_result) -> + returnTc (pcs, tc_result) + where + tycl_decls = [d | TyClD d <- decls] + rule_decls = [d | RuleD d <- decls] + inst_decls = [d | InstD d <- decls] + val_decls = [d | ValD d <- decls] + + (src_inst_decls, iface_inst_decls) = partition isSourceInstDecl inst_decls + (src_rule_decls, iface_rule_decls) = partition (isSourceRuleDecl this_mod) rule_decls + val_binds = foldr ThenBinds EmptyBinds val_decls +\end{code} - -- 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. + +%************************************************************************ +%* * +\subsection{Typechecking interface decls} +%* * +%************************************************************************ + +\begin{code} +typecheckIface + :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> ModIface -- Iface for this module (just module & fixities) + -> [RenamedHsDecl] + -> IO (Maybe (PersistentCompilerState, ModDetails)) + -- The new PCS is Augmented with imported information, + -- (but not stuff from this module). + +typecheckIface dflags pcs hst mod_iface decls + = do { maybe_tc_stuff <- typecheck dflags pcs hst alwaysQualify $ + tcIface pcs this_mod decls + ; printIfaceDump dflags maybe_tc_stuff + ; return maybe_tc_stuff } + where + this_mod = mi_module mod_iface + +tcIface pcs this_mod decls +-- The decls are coming from this_mod's interface file, together +-- with imported interface decls that belong in the "package" stuff. +-- (With GHCi, all the home modules have already been processed.) +-- That is why we need to do the partitioning below. + = tcIfaceImports this_mod decls `thenTc` \ (_, all_things, dfuns, rules) -> + + let + -- Do the partitioning (see notes above) + (local_things, imported_things) = partition (isLocalThing this_mod) all_things + (local_rules, imported_rules) = partition is_local_rule rules + (local_dfuns, imported_dfuns) = partition (isLocalThing this_mod) dfuns + is_local_rule (IfaceRuleOut n _) = isLocalThing this_mod n + in + addInstDFuns (pcs_insts pcs) imported_dfuns `thenNF_Tc` \ new_pcs_insts -> let - all_binds = val_binds `AndMonoBinds` - inst_binds `AndMonoBinds` - cls_dm_binds `AndMonoBinds` - const_inst_binds `AndMonoBinds` - foe_binds + new_pcs_pte :: PackageTypeEnv + new_pcs_pte = extendTypeEnvList (pcs_PTE pcs) imported_things + new_pcs_rules = addIfaceRules (pcs_rules pcs) imported_rules + + new_pcs :: PersistentCompilerState + new_pcs = pcs { pcs_PTE = new_pcs_pte, + pcs_insts = new_pcs_insts, + pcs_rules = new_pcs_rules + } + + mod_details = ModDetails { md_types = mkTypeEnv local_things, + md_insts = local_dfuns, + md_rules = [(id,rule) | IfaceRuleOut id rule <- local_rules], + md_binds = [] } + -- All the rules from an interface are of the IfaceRuleOut form in --- traceTc (text "Tc9") `thenNF_Tc_` - zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) -> - tcSetEnv final_env $ - -- zonkTopBinds puts all the top-level Ids into the tcGEnv - zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' -> - 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 (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 - } + returnTc (new_pcs, mod_details) + + +tcIfaceImports :: Module + -> [RenamedHsDecl] -- All interface-file decls + -> TcM (TcEnv, [TyThing], [DFunId], [TypecheckedRuleDecl]) +tcIfaceImports this_mod decls +-- The decls are all interface-file declarations + = let + inst_decls = [d | InstD d <- decls] + tycl_decls = [d | TyClD d <- decls] + rule_decls = [d | RuleD d <- decls] + in + fixTc (\ ~(unf_env, _, _, _) -> + -- This fixTc follows the same general plan as tcImports, + -- which is better commented (below) + tcTyAndClassDecls unf_env this_mod tycl_decls `thenTc` \ tycl_things -> + tcExtendGlobalEnv tycl_things $ + tcInterfaceSigs unf_env this_mod tycl_decls `thenTc` \ sig_ids -> + tcExtendGlobalValEnv sig_ids $ + tcIfaceInstDecls1 inst_decls `thenTc` \ dfuns -> + tcIfaceRules rule_decls `thenTc` \ rules -> + tcGetEnv `thenTc` \ env -> + let + all_things = map AnId sig_ids ++ tycl_things + in + returnTc (env, all_things, dfuns, rules) ) - 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} -tcImports :: PersistentCompilerState +tcImports :: RecTcEnv + -> PersistentCompilerState -> HomeSymbolTable - -> (Name -> Maybe Fixity) -> Module - -> [RenamedHsDecl] - -> TcM (TcEnv, PersistentCompilerState, - [InstInfo], RenamedHsBinds, [TypecheckedRuleDecl]) + -> [RenamedTyClDecl] + -> [RenamedInstDecl] + -> [RenamedRuleDecl] + -> TcM (TcEnv, PersistentCompilerState) -- 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 +-- It deals with everything that could be an import: +-- type and class decls (some source, some imported) +-- interface signatures (checked lazily) +-- instance decls (some source, some imported) +-- rule decls (all imported) -- These can occur in source code too, of course +-- +-- tcImports is only called when processing source code, +-- so that any interface-file declarations are for other modules, not this one -tcImports pcs hst get_fixity this_mod decls - = fixTc (\ ~(unf_env, _, _, _, _) -> - -- (unf_env :: RecTcEnv) is used for type-checking interface pragmas +tcImports unf_env pcs hst this_mod + tycl_decls inst_decls rule_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 - --- 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_inst_info, deriv_binds) -> - tcSetInstEnv inst_env $ + + = 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 this_mod tycl_decls `thenTc` \ tycl_things -> + tcExtendGlobalEnv tycl_things $ + -- 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_inst_info, deriv_binds, local_rules) - ) + traceTc (text "Tc2") `thenNF_Tc_` + tcInterfaceSigs unf_env this_mod tycl_decls `thenTc` \ sig_ids -> + tcExtendGlobalValEnv sig_ids $ + + -- Typecheck the instance decls, includes deriving + -- Note that imported dictionary functions are already + -- in scope from the preceding tcInterfaceSigs + traceTc (text "Tc3") `thenNF_Tc_` + tcIfaceInstDecls1 inst_decls `thenTc` \ dfuns -> + tcIfaceRules rule_decls `thenNF_Tc` \ rules -> + + addInstDFuns (pcs_insts pcs) dfuns `thenNF_Tc` \ new_pcs_insts -> + tcGetEnv `thenTc` \ unf_env -> + let + -- 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 = map AnId sig_ids ++ -- All imported + filter (not . isLocalThing this_mod) tycl_things + + new_pte :: PackageTypeEnv + new_pte = extendTypeEnvList (pcs_PTE pcs) imported_things + + new_pcs_rules = addIfaceRules (pcs_rules pcs) rules + + 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) + +isSourceRuleDecl :: Module -> RenamedRuleDecl -> Bool +-- This is a bit gruesome. +-- Usually, HsRules come only from source files; IfaceRules only from interface files +-- But built-in rules appear as an IfaceRuleOut... and when compiling +-- the source file for that built-in rule, we want to treat it as a source +-- rule, so it gets put with the other rules for that module. +isSourceRuleDecl this_mod (HsRule _ _ _ _ _ _) = True +isSourceRuleDecl this_mod (IfaceRule _ _ _ n _ _ _) = False +isSourceRuleDecl this_mod (IfaceRuleOut name _) = isLocalThing this_mod name + +addIfaceRules rule_base rules + = foldl add_rule rule_base rules where - tycl_decls = [d | TyClD d <- decls] - iface_rules = [d | RuleD d <- decls, isIfaceRuleDecl d] + add_rule rule_base (IfaceRuleOut id rule) = extendRuleBase rule_base (id, rule) \end{code} + %************************************************************************ %* * \subsection{Checking the type of main} @@ -388,89 +680,114 @@ tcImports pcs hst get_fixity this_mod decls %************************************************************************ We must check that in module Main, - a) main is defined - b) main :: forall a1...an. IO t, for some type t + a) Main.main is in scope + b) Main.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. +Then we build + $main = PrelTopHandler.runMain Main.main -So we just instantiate the type and unify with IO t, and declare -victory if doing so succeeds. +The function + PrelTopHandler :: IO a -> IO () +catches the top level exceptions. +It accepts a Main.main of any type (IO a). \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 +tcCheckMain :: Maybe Name -> TcM (TypecheckedMonoBinds, LIE) +tcCheckMain Nothing = returnTc (EmptyMonoBinds, emptyLIE) + +tcCheckMain (Just main_name) + = tcLookupId main_name `thenNF_Tc` \ main_id -> + -- If it is not Nothing, it should be in the env + tcAddSrcLoc (getSrcLoc main_id) $ + tcAddErrCtxt mainCtxt $ + newTyVarTy liftedTypeKind `thenNF_Tc` \ ty -> + tcMonoExpr rhs ty `thenTc` \ (main_expr, lie) -> + zonkTcType ty `thenNF_Tc` \ ty -> + ASSERT( is_io_unit ty ) + let + dollar_main_id = setIdLocalExported (mkLocalId dollarMainName ty) + in + returnTc (VarMonoBind dollar_main_id main_expr, lie) 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"))] + rhs = HsApp (HsVar runMainName) (HsVar main_name) + +is_io_unit :: Type -> Bool -- True for IO () +is_io_unit tau = case tcSplitTyConApp_maybe tau of + Just (tc, [arg]) -> getName tc == ioTyConName && isUnitTy arg + other -> False + +mainCtxt = ptext SLIT("When checking the type of 'main'") \end{code} %************************************************************************ %* * -\subsection{Dumping output} +\subsection{Interfacing the Tc monad to the IO monad} %* * %************************************************************************ \begin{code} -printTcDump dflags Nothing = return () -printTcDump dflags (Just (_, results)) - = do dumpIfSet_dyn dflags Opt_D_dump_types - "Type signatures" (dump_sigs results) - dumpIfSet_dyn dflags Opt_D_dump_tc - "Typechecked" (dump_tc results) +typecheck :: DynFlags + -> PersistentCompilerState + -> HomeSymbolTable + -> PrintUnqualified -- For error printing + -> TcM r + -> IO (Maybe r) -dump_tc results - = vcat [ppr (tc_binds results), - pp_rules (tc_rules results), - ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)] - ] +typecheck dflags pcs hst unqual thing_inside + = do { showPass dflags "Typechecker"; + ; env <- initTcEnv hst (pcs_PTE pcs) + + ; (maybe_tc_result, errs) <- initTc dflags env thing_inside + + ; printErrorsAndWarnings unqual errs -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)) - | AnId id <- nameEnvElts (tc_env results), - want_sig id + ; if errorsFound errs then + return Nothing + else + return maybe_tc_result + } +\end{code} + + +%************************************************************************ +%* * +\subsection{Dumping output} +%* * +%************************************************************************ + +\begin{code} +printTcDump dflags unqual Nothing = return () +printTcDump dflags unqual (Just (_, results)) + = do if dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags then + printForUser stdout unqual (dump_tc_iface dflags results) + else return () + + dumpIfSet_dyn dflags Opt_D_dump_tc + "Typechecked" (ppr (tc_binds results)) + + +printIfaceDump dflags Nothing = return () +printIfaceDump dflags (Just (_, details)) + = dumpIfSet_dyn_or dflags [Opt_D_dump_types, Opt_D_dump_tc] + "Interface" (pprModDetails details) + +dump_tc_iface dflags results + = vcat [pprModDetails (ModDetails {md_types = tc_env results, + md_insts = tc_insts results, + md_rules = [], md_binds = []}) , + ppr_rules (tc_rules results), + + if dopt Opt_Generics dflags then + ppr_gen_tycons (typeEnvTyCons (tc_env results)) + else + empty ] - 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_rules [] = empty +ppr_rules rs = vcat [ptext SLIT("{-# RULES"), + nest 4 (vcat (map ppr rs)), + ptext SLIT("#-}")] ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"), vcat (map ppr_gen_tycon tcs), @@ -485,15 +802,10 @@ ppr_gen_tycon tycon | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable") ppr_ep (EP from to) - = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau), + = vcat [ ptext SLIT("Rep type:") <+> ppr (tcFunResultTy 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("#-}")] + (_,from_tau) = tcSplitForAllTys (idType from) \end{code}