%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcModule]{Typechecking a whole module}
\begin{code}
-#include "HsVersions.h"
-
module TcModule (
- tcModule
+ typecheckModule, typecheckExpr, TcResults(..)
) where
-import Ubiq
+#include "HsVersions.h"
-import HsSyn ( HsModule(..), HsBinds(..), Bind, HsExpr,
- TyDecl, SpecDataSig, ClassDecl, InstDecl,
- SpecInstSig, DefaultDecl, Sig, Fake, InPat,
- FixityDecl, IE, ImportDecl
+import CmdLineOpts ( DynFlag(..), DynFlags, opt_PprStyle_Debug )
+import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..), HsExpr(..),
+ isIfaceRuleDecl, nullBinds, andMonoBindList
)
-import RnHsSyn ( RenamedHsModule(..), RenamedFixityDecl(..) )
-import TcHsSyn ( TypecheckedHsBinds(..), TypecheckedHsExpr(..),
- TcIdOcc(..), zonkBinds, zonkInst, zonkId )
+import HsTypes ( toHsType )
+import PrelNames ( mAIN_Name, mainName, ioTyConName, printName )
+import RnHsSyn ( RenamedHsBinds, RenamedHsDecl, RenamedHsExpr )
+import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr,
+ TypecheckedForeignDecl, TypecheckedRuleDecl,
+ zonkTopBinds, zonkForeignExports, zonkRules, mkHsLet,
+ zonkExpr
+ )
+
import TcMonad
-import Inst ( Inst, plusLIE )
-import TcBinds ( tcBindsAndThen )
+import TcType ( newTyVarTy, zonkTcType, tcInstType )
+import TcUnify ( unifyTauTy )
+import Inst ( plusLIE )
+import VarSet ( varSetElems )
+import TcBinds ( tcTopBinds )
import TcClassDcl ( tcClassDecls2 )
-import TcDefaults ( tcDefaults )
-import TcEnv ( tcExtendGlobalValEnv, getEnv_LocalIds,
- getEnv_TyCons, getEnv_Classes,
- tcLookupLocalValueByKey, tcLookupTyConByKey )
+import TcDefaults ( tcDefaults, defaultDefaultTys )
+import TcExpr ( tcMonoExpr )
+import TcEnv ( TcEnv, InstInfo, tcExtendGlobalValEnv, tcLookup_maybe,
+ isLocalThing, tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv,
+ TcTyThing(..), tcLookupTyCon
+ )
+import TcRules ( tcIfaceRules, tcSourceRules )
+import TcForeign ( tcForeignImports, tcForeignExports )
import TcIfaceSig ( tcInterfaceSigs )
import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
-import TcInstUtil ( buildInstanceEnvs, InstInfo )
-import TcSimplify ( tcSimplifyTop )
-import TcTyClsDecls ( tcTyAndClassDecls1 )
-
-import Bag ( listToBag )
-import Class ( GenClass )
-import Id ( GenId, isDataCon, isMethodSelId, idType )
-import Maybes ( catMaybes )
-import Outputable ( isExported, isLocallyDefined )
-import PrelInfo ( unitTy, mkPrimIoTy )
-import Pretty
-import RnUtils ( GlobalNameMappers(..), GlobalNameMapper(..) )
-import TyCon ( TyCon )
-import Type ( applyTyCon )
-import Unify ( unifyTauTy )
-import UniqFM ( lookupUFM_Directly, lookupWithDefaultUFM_Directly,
- filterUFM, eltsUFM )
-import Unique ( iOTyConKey, mainIdKey, mainPrimIOIdKey )
+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 TyCon ( tyConGenInfo )
import Util
-
-
-import FiniteMap ( emptyFM )
-tycon_specs = emptyFM
-
-
+import BasicTypes ( EP(..), Fixity )
+import Outputable
+import HscTypes ( PersistentCompilerState(..), HomeSymbolTable,
+ PackageTypeEnv, ModIface(..),
+ TypeEnv, extendTypeEnvList,
+ TyThing(..), implicitTyThingIds,
+ mkTypeEnv
+ )
\end{code}
+Outside-world interface:
\begin{code}
-tcModule :: GlobalNameMappers -- final renamer info for derivings
- -> RenamedHsModule -- input
- -> TcM s ((TypecheckedHsBinds, -- record selector binds
- TypecheckedHsBinds, -- binds from class decls; does NOT
- -- include default-methods bindings
- TypecheckedHsBinds, -- binds from instance decls; INCLUDES
- -- class default-methods binds
- TypecheckedHsBinds, -- binds from value decls
-
- [(Id, TypecheckedHsExpr)]), -- constant instance binds
-
- ([RenamedFixityDecl], [Id], [TyCon], [Class], Bag InstInfo),
- -- things for the interface generator
-
- ([TyCon], [Class]),
- -- environments of info from this module only
-
- FiniteMap TyCon [(Bool, [Maybe Type])],
- -- source tycon specialisation requests
-
- PprStyle -> Pretty) -- -ddump-deriving info
-
-tcModule renamer_name_funs
- (HsModule mod_name verion exports imports fixities
- ty_decls specdata_sigs cls_decls inst_decls specinst_sigs
- default_decls val_decls sigs src_loc)
- = ASSERT(null imports)
-
- tcAddSrcLoc src_loc $ -- record where we're starting
-
- -- Tie the knot for inteface-file value declaration signatures
- -- This info is only used inside the knot for type-checking the
- -- pragmas, which is done lazily [ie failure just drops the pragma
- -- without having any global-failure effect].
-
- fixTc (\ ~(_, _, _, _, _, _, sig_ids) ->
- tcExtendGlobalValEnv sig_ids (
-
- -- The knot for instance information. This isn't used at all
- -- till we type-check value declarations
- fixTc ( \ ~(rec_inst_mapper, _, _, _, _, _) ->
-
- -- Type-check the type and class decls
- trace "tcTyAndClassDecls:" $
- tcTyAndClassDecls1 rec_inst_mapper ty_decls_bag cls_decls_bag
- `thenTc` \ (env, record_binds) ->
-
- -- Typecheck the instance decls, includes deriving
- tcSetEnv env (
- trace "tcInstDecls:" $
- tcInstDecls1 inst_decls_bag specinst_sigs
- mod_name renamer_name_funs fixities
- ) `thenTc` \ (inst_info, deriv_binds, ddump_deriv) ->
-
- buildInstanceEnvs inst_info `thenTc` \ inst_mapper ->
-
- returnTc (inst_mapper, env, record_binds, inst_info, deriv_binds, ddump_deriv)
-
- ) `thenTc` \ (_, env, record_binds, inst_info, deriv_binds, ddump_deriv) ->
- tcSetEnv env (
-
- -- Default declarations
- tcDefaults default_decls `thenTc` \ defaulting_tys ->
- tcSetDefaultTys defaulting_tys ( -- for the iface sigs...
-
- -- 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
- tcInterfaceSigs sigs `thenTc` \ sig_ids ->
-
- returnTc (env, inst_info, record_binds, deriv_binds, ddump_deriv, defaulting_tys, sig_ids)
-
- )))) `thenTc` \ (env, inst_info, record_binds, deriv_binds, ddump_deriv, defaulting_tys, _) ->
+-- 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
+ }
+
+---------------
+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)
+
+
+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 }
+ where
+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
+
+---------------
+typecheckExpr :: DynFlags
+ -> Bool -- True <=> wrap in 'print' to get a result of IO type
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> PrintUnqualified -- For error printing
+ -> Module
+ -> (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 (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 ->
+ 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)
+ in
+ 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)
- tcSetEnv env ( -- to the end...
- tcSetDefaultTys defaulting_tys ( -- ditto
+ 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 expr ty `thenTc` \ (expr', lie) ->
+ returnTc (expr', lie, ty)
+
+ where
+ -- (tc_io_expr e) typechecks 'e' if that gives a result of IO t,
+ -- or 'print e' otherwise. Either way the result is of type IO t
+ tc_io_expr e = newTyVarTy openTypeKind `thenTc` \ ty ->
+ tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon ->
+ let
+ res_ty = mkTyConApp ioTyCon [ty]
+ in
+ tcMonoExpr expr res_ty `thenTc` \ (expr', lie) ->
+ returnTc (expr', 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)
+
+ ; (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 :: PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> 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) ->
+
+ 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
- trace "tcBinds:" $
- tcBindsAndThen
- (\ binds1 (binds2, thing) -> (binds1 `ThenBinds` binds2, thing))
- (val_decls `ThenBinds` deriv_binds)
- ( -- Second pass over instance declarations,
- -- to compile the bindings themselves.
- tcInstDecls2 inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
- tcClassDecls2 cls_decls_bag `thenNF_Tc` \ (lie_clasdecls, cls_binds) ->
- tcGetEnv `thenNF_Tc` \ env ->
- returnTc ( (EmptyBinds, (inst_binds, cls_binds, env)),
- lie_instdecls `plusLIE` lie_clasdecls,
- () ))
-
- `thenTc` \ ((val_binds, (inst_binds, cls_binds, final_env)), lie_alldecls, _) ->
-
- checkTopLevelIds mod_name final_env `thenTc_`
-
- -- 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.)
- tcSimplifyTop lie_alldecls `thenTc` \ const_insts ->
+-- 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
- localids = getEnv_LocalIds final_env
- tycons = getEnv_TyCons final_env
- classes = getEnv_Classes final_env
-
- local_tycons = filter isLocallyDefined tycons
- local_classes = filter isLocallyDefined classes
+ lie_alldecls = lie_valdecls `plusLIE`
+ lie_instdecls `plusLIE`
+ lie_clasdecls `plusLIE`
+ lie_fodecls `plusLIE`
+ lie_rules
+ in
+ tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
- exported_ids = [v | v <- localids,
- isExported v && not (isDataCon v) && not (isMethodSelId v)]
+ -- 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 = val_binds `AndMonoBinds`
+ inst_binds `AndMonoBinds`
+ cls_dm_binds `AndMonoBinds`
+ const_inst_binds `AndMonoBinds`
+ foe_binds
in
- -- Backsubstitution. Monomorphic top-level decls may have
- -- been instantiated by subsequent decls, and the final
- -- simplification step may have instantiated some
- -- ambiguous types. So, sadly, we need to back-substitute
- -- over the whole bunch of bindings.
- zonkBinds record_binds `thenNF_Tc` \ record_binds' ->
- zonkBinds val_binds `thenNF_Tc` \ val_binds' ->
- zonkBinds inst_binds `thenNF_Tc` \ inst_binds' ->
- zonkBinds cls_binds `thenNF_Tc` \ cls_binds' ->
- mapNF_Tc zonkInst const_insts `thenNF_Tc` \ const_insts' ->
- mapNF_Tc (zonkId.TcId) exported_ids `thenNF_Tc` \ exported_ids' ->
-
- -- FINISHED AT LAST
- returnTc (
- (record_binds', cls_binds', inst_binds', val_binds', const_insts'),
-
- -- the next collection is just for mkInterface
- (fixities, exported_ids', tycons, classes, inst_info),
-
- (local_tycons, local_classes),
-
- tycon_specs,
-
- ddump_deriv
- )))
+-- 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
+ }
+ )
where
- ty_decls_bag = listToBag ty_decls
- cls_decls_bag = listToBag cls_decls
- inst_decls_bag = listToBag inst_decls
-
+ 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
+ -> 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 pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _, _, _) ->
+ -- (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 $
+
+ -- 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) ->
+
+ 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)
+ )
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ iface_rules = [d | RuleD d <- decls, isIfaceRuleDecl d]
+\end{code}
+
%************************************************************************
%* *
-\subsection{Error checking 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.
-checkTopLevelIds checks that Main.main or Main.mainPrimIO has correct type.
+So we just instantiate the type and unify with IO t, and declare
+victory if doing so succeeds.
\begin{code}
-checkTopLevelIds :: FAST_STRING -> TcEnv s -> TcM s ()
-checkTopLevelIds mod final_env
- | mod /= SLIT("Main")
+tcCheckMain :: Module -> TcM ()
+tcCheckMain this_mod
+ | not (moduleName this_mod == mAIN_Name )
= returnTc ()
| otherwise
- = tcSetEnv final_env (
- tcLookupLocalValueByKey mainIdKey `thenNF_Tc` \ maybe_main ->
- tcLookupLocalValueByKey mainPrimIOIdKey `thenNF_Tc` \ maybe_prim ->
- tcLookupTyConByKey iOTyConKey `thenNF_Tc` \ io_tc ->
-
- case (maybe_main, maybe_prim) of
- (Just main, Nothing) -> tcAddErrCtxt mainCtxt $
- unifyTauTy (applyTyCon io_tc [unitTy])
- (idType main)
-
- (Nothing, Just prim) -> tcAddErrCtxt primCtxt $
- unifyTauTy (mkPrimIoTy unitTy)
- (idType prim)
-
- (Just _ , Just _ ) -> failTc mainBothIdErr
- (Nothing, Nothing) -> failTc mainNoneIdErr
- )
-
-mainCtxt sty
- = ppStr "main should have type IO ()"
+ = -- 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}
-primCtxt sty
- = ppStr "mainPrimIO should have type PrimIO ()"
-mainBothIdErr sty
- = ppStr "module Main contains definitions for both main and mainPrimIO"
+%************************************************************************
+%* *
+\subsection{Dumping output}
+%* *
+%************************************************************************
-mainNoneIdErr sty
- = panic "ToDo: sort out mainIdKey"
- -- ppStr "module Main does not contain a definition for main (or mainPrimIO)"
+\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)
+
+dump_tc results
+ = vcat [ppr (tc_binds results),
+ pp_rules (tc_rules results),
+ ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)]
+ ]
+
+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
+ ]
+ 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}
projects / ghc-hetmet.git / blobdiff