%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1995
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcModule]{Typechecking a whole module}
\begin{code}
-#include "HsVersions.h"
-
module TcModule (
- tcModule,
-
- -- to make the interface self-sufficient...
- Module, Bag, CE(..), E, Binds, FixityDecl, Expr, InPat,
- RenamedPat(..), TypecheckedPat, Id, Inst, Maybe, TcResult,
- Name, ProtoName, SrcLoc, Subst, TCE(..), UniqFM,
- Error(..), Pretty(..), PprStyle, PrettyRep, InstInfo
+ typecheckModule,
+ TcResults(..)
) where
-import TcMonad -- typechecking monad machinery
-import AbsSyn -- the stuff being typechecked
-
--- OLD:
---import AbsPrel ( stringTy,
--- eqStringId, neStringId, ltStringId,
--- leStringId, geStringId, gtStringId,
--- maxStringId, minStringId, tagCmpStringId,
--- dfunEqStringId, dfunOrdStringId,
--- pRELUDE_CORE
--- IF_ATTACK_PRAGMAS(COMMA mkListTy COMMA charTy)
--- )
---#if USE_ATTACK_PRAGMAS
---import PrelVals ( string_cmp_id ) -- shouldn't even be visible, really
---#endif
-import BackSubst ( applyTcSubstToBinds )
-import Bag ( unionBags, bagToList, emptyBag, listToBag )
-import CE ( nullCE, checkClassCycles, lookupCE, CE(..) )
-import CmdLineOpts ( GlobalSwitch(..) )
-import E
-import HsCore -- ****** NEED TO SEE CONSTRUCTORS ******
-import HsPragmas -- ****** NEED TO SEE CONSTRUCTORS ******
-import InstEnv
-import LIE ( unMkLIE, plusLIE, LIE )
-import Name ( Name(..) )
-import RenameAuxFuns ( GlobalNameFuns(..), GlobalNameFun(..), ProtoName, Maybe )
-import SrcLoc ( mkBuiltinSrcLoc, SrcLoc )
-import TCE ( checkTypeCycles, TCE(..), UniqFM )
+#include "HsVersions.h"
+
+import CmdLineOpts ( opt_D_dump_tc )
+import HsSyn ( HsModule(..), HsBinds(..), MonoBinds(..), HsDecl(..) )
+import RnHsSyn ( RenamedHsModule )
+import TcHsSyn ( TcMonoBinds, TypecheckedMonoBinds,
+ TypecheckedForeignDecl, TypecheckedRuleDecl,
+ zonkTopBinds, zonkForeignExports, zonkRules
+ )
+
+import TcMonad
+import Inst ( Inst, emptyLIE, plusLIE )
import TcBinds ( tcTopBindsAndThen )
-import TcClassDcl ( tcClassDecls1, tcClassDecls2, ClassInfo )
+import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds )
import TcDefaults ( tcDefaults )
-import TcDeriv ( tcDeriving )
+import TcEnv ( tcExtendGlobalValEnv, tcExtendTypeEnv,
+ getEnvTyCons, getEnvClasses, tcLookupValueMaybe,
+ explicitLookupValueByKey, tcSetValueEnv,
+ tcLookupTyCon, initEnv,
+ ValueEnv, TcTyThing(..)
+ )
+import TcExpr ( tcId )
+import TcRules ( tcRules )
+import TcForeign ( tcForeignImports, tcForeignExports )
import TcIfaceSig ( tcInterfaceSigs )
-import TcInstDcls ( tcInstDecls1, tcInstDecls2, tcSpecInstSigs, buildInstanceEnvs, InstInfo(..) )
+import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
+import TcInstUtil ( buildInstanceEnvs, classDataCon, InstInfo )
import TcSimplify ( tcSimplifyTop )
-import TcTyDecls ( tcTyDecls )
-import Unique -- some ClassKey stuff
-import UniqFM ( emptyUFM ) -- profiling, pragmas only
+import TcTyClsDecls ( tcTyAndClassDecls )
+import TcTyDecls ( mkImplicitDataBinds )
+import TcType ( TcType, typeToTcType,
+ TcKind, kindToTcKind,
+ newTyVarTy
+ )
+
+import RnMonad ( RnNameSupply, getIfaceFixities, Fixities, InterfaceDetails )
+import Bag ( isEmptyBag )
+import ErrUtils ( Message, printErrorsAndWarnings, dumpIfSet )
+import Id ( Id, idType )
+import Module ( pprModuleName )
+import Name ( Name, nameUnique, isLocallyDefined, NamedThing(..) )
+import TyCon ( TyCon, tyConKind )
+import Class ( Class, classSelIds, classTyCon )
+import Type ( mkTyConApp, mkForAllTy,
+ boxedTypeKind, getTyVar, Type )
+import TysWiredIn ( unitTy )
+import PrelMods ( mAIN_Name )
+import PrelInfo ( main_NAME, thinAirIdNames, setThinAirIds )
+import TcUnify ( unifyTauTy )
+import Unique ( Unique )
+import UniqSupply ( UniqSupply )
+import Maybes ( maybeToBool )
import Util
+import Bag ( Bag, isEmptyBag )
+import Outputable
-import Pretty -- Debugging
+import IOExts
\end{code}
+Outside-world interface:
\begin{code}
-tcModule :: E -- initial typechecker environment
- -> GlobalNameFuns -- final renamer info (to do derivings)
- -> RenamedModule -- input
- -> TcM ((TypecheckedBinds, -- binds from class decls; does NOT
- -- include default-methods bindings
- TypecheckedBinds, -- binds from instance decls; INCLUDES
- -- class default-methods binds
- TypecheckedBinds, -- binds from value decls
- [(Inst, TypecheckedExpr)]),
-
- ([RenamedFixityDecl], -- things for the interface generator
- [Id], -- to look at...
- CE,
- TCE,
- Bag InstInfo),
-
- FiniteMap TyCon [[Maybe UniType]],
- -- source tycon specialisation requests
-
---UNUSED: E, -- environment of total accumulated info
- E, -- environment of info due to this module only
- PprStyle -> Pretty) -- -ddump-deriving info (passed upwards)
-
-tcModule e1 renamer_name_funs
- (Module mod_name exports imports_should_be_empty fixities
- tydecls ty_sigs classdecls instdecls specinst_sigs
- default_decls valdecls sigs src_loc)
-
- = addSrcLocTc 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 (\ ~(rec_gve_sigs, _, _, _, _, _, _, _, _, _) ->
- let
- e2 = plusE_GVE e1 rec_gve_sigs
- in
-
- -- The knot for instance information. This isn't used at all
- -- till we type-check value declarations.
- fixTc ( \ ~(rec_inst_mapper, _, _, _, _, _, _, _, _) ->
-
- -- The knot for TyCons and Classes
- fixTc ( \ ~(_, rec_tce, rec_ce, rec_datacons_gve, rec_ops_gve, _, _) ->
- let
- e3 = e2
- `plusE_GVE` rec_datacons_gve
- `plusE_GVE` rec_ops_gve
- `plusE_TCE` rec_tce
- `plusE_CE` rec_ce
- in
- -- DO THE TYPE DECLS
- -- Including the pragmas: {-# ABSTRACT TypeSyn #-}
- -- {-# SPECIALIZE data DataType ... #-}
- let
- (absty_sigs, specdata_sigs) = partition is_absty_sig ty_sigs
- is_absty_sig (AbstractTypeSig _ _) = True
- is_absty_sig (SpecDataSig _ _ _) = False
-
- is_abs_syn :: Name -> Bool -- a lookup fn for abs synonyms
- is_abs_syn n
- = n `is_elem` [ tc | (AbstractTypeSig tc _) <- absty_sigs ]
- where
- is_elem = isIn "tcModule"
-
- get_spec_sigs :: Name -> [RenamedDataTypeSig]
- get_spec_sigs n
- = [ sig | sig@(SpecDataSig tc _ _) <- specdata_sigs, n == tc]
- in
- babyTcMtoTcM (tcTyDecls e3 is_abs_syn get_spec_sigs tydecls)
- `thenTc` \ (tce, datacons_gve, tycon_specs) ->
-
- -- DO THE CLASS DECLS
- tcClassDecls1 e3 rec_inst_mapper classdecls
- `thenTc` \ (class_info, ce, ops_gve) ->
-
- -- End of TyCon/Class knot
- -- Augment whatever TCE/GVE/CE stuff was in orig_e
- returnTc (e3, tce, ce, datacons_gve, ops_gve, class_info, tycon_specs)
-
- -- End of inner fixTc
- ) `thenTc` ( \ (e3, tce_here, ce_here, _, _, class_info, tycon_specs) ->
- -- The "here" things are the extra decls defined in this
- -- module or its imports; but not including whatever was
- -- in the incoming e.
-
- -- Grab completed tce/ce and check for type/class cycles
- -- The tce/ce are now stable and lookable-at, with the
- -- exception of the instance information inside classes
- let
- ce3 = getE_CE e3
- tce3 = getE_TCE e3
- in
- checkMaybeErrTc (checkTypeCycles tce3) id `thenTc_`
- checkMaybeErrTc (checkClassCycles ce3) id `thenTc_`
-
- -- Now instance declarations
- tcInstDecls1 e3 ce3 tce3 instdecls `thenNF_Tc` \ decl_inst_info ->
-
- -- Handle "derived" instances; note that we only do derivings
- -- for things in this module; we ignore deriving decls from
- -- interfaces! We pass fixities, because they may be used in
- -- doing Text.
-
- tcDeriving mod_name renamer_name_funs decl_inst_info tce3 fixities
- `thenTc` \ (deriv_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- let
- inst_info = deriv_inst_info `unionBags` decl_inst_info
- in
- -- Handle specialise instance pragmas
--- getSwitchCheckerTc `thenNF_Tc` \ sw_chkr ->
--- (if sw_chkr GlasgowExts then
- tcSpecInstSigs e3 ce3 tce3 inst_info specinst_sigs
--- else
--- returnTc emptyBag)
- `thenTc` \ spec_inst_info ->
- let
- full_inst_info = inst_info `unionBags` spec_inst_info
- in
- -- OK, now do the inst-mapper stuff
- buildInstanceEnvs full_inst_info `thenTc` \ all_insts_mapper ->
-
- returnTc (all_insts_mapper, e3, ce_here, tce_here, class_info, tycon_specs,
- full_inst_info, extra_deriv_binds, ddump_deriv)
-
- -- End of outer fixTc
- )) `thenTc` ( \ (_, e3, ce_here, tce_here, class_info, tycon_specs,
- full_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- -- Default declarations
- tcDefaults e3 default_decls `thenTc` \ defaulting_tys ->
- setDefaultingTys 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
-
- babyTcMtoTcM (tcInterfaceSigs e3 sigs) `thenTc` \ gve_sigs ->
-
- returnTc (gve_sigs, e3, ce_here, tce_here, class_info, tycon_specs, defaulting_tys,
- full_inst_info, extra_deriv_binds, ddump_deriv)
-
- -- End of extremely outer fixTc
- ))) `thenTc` \ (_, e3, ce_here, tce_here, class_info, tycon_specs, defaulting_tys,
- full_inst_info, extra_deriv_binds, ddump_deriv) ->
-
- setDefaultingTys defaulting_tys ( -- to the end...
+-- Convenient type synonyms first:
+data TcResults
+ = TcResults {
+ tc_binds :: TypecheckedMonoBinds,
+ tc_tycons :: [TyCon],
+ tc_classes :: [Class],
+ tc_insts :: Bag InstInfo, -- Instance declaration information
+ tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports.
+ tc_rules :: [TypecheckedRuleDecl], -- Transformation rules
+ tc_env :: ValueEnv,
+ tc_thinair :: [Id] -- The thin-air Ids
+ }
+
+---------------
+typecheckModule
+ :: UniqSupply
+ -> RnNameSupply
+ -> InterfaceDetails
+ -> RenamedHsModule
+ -> IO (Maybe TcResults)
+
+typecheckModule us rn_name_supply iface_det mod
+ = initTc us initEnv (tcModule rn_name_supply (getIfaceFixities iface_det) mod)
+ >>= \ (maybe_result, warns, errs) ->
+
+ printErrorsAndWarnings errs warns >>
+
+ -- write the thin-air Id map
+ (case maybe_result of
+ Just results -> setThinAirIds (tc_thinair results)
+ Nothing -> return ()
+ ) >>
+
+ dumpIfSet opt_D_dump_tc "Typechecked"
+ (case maybe_result of
+ Just results -> ppr (tc_binds results)
+ $$
+ pp_rules (tc_rules results)
+ Nothing -> text "Typecheck failed") >>
+
+ return (if isEmptyBag errs then
+ maybe_result
+ else
+ Nothing)
+
+pp_rules [] = empty
+pp_rules rs = vcat [ptext SLIT("{-# RULES"),
+ nest 4 (vcat (map ppr rs)),
+ ptext SLIT("#-}")]
+\end{code}
+
+The internal monster:
+\begin{code}
+tcModule :: RnNameSupply -- for renaming derivings
+ -> Fixities -- needed for Show/Read derivings.
+ -> RenamedHsModule -- input
+ -> TcM s TcResults -- output
+
+tcModule rn_name_supply fixities
+ (HsModule mod_name verion exports imports 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
+
+ -- 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
+ tcTyAndClassDecls unf_env rec_inst_mapper 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) ->
+
+ buildInstanceEnvs inst_info `thenNF_Tc` \ inst_mapper ->
+
+ returnTc (inst_mapper, env, inst_info, deriv_binds)
+
+ -- End of inner fix loop
+ ) `thenTc` \ (_, env, inst_info, deriv_binds) ->
+
+ tcSetEnv env (
+
+ -- Default declarations
+ tcDefaults decls `thenTc` \ defaulting_tys ->
+ tcSetDefaultTys defaulting_tys $
+
+ -- 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
+ let
+ tycons = getEnvTyCons env
+ classes = getEnvClasses env
+ local_tycons = filter isLocallyDefined tycons
+ local_classes = filter isLocallyDefined classes
+ in
+ 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 $
+
+ -- 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), Nothing, ATyCon 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
+ tcInterfaceSigs unf_env decls `thenTc` \ sig_ids ->
+ tcExtendGlobalValEnv sig_ids $
+
+ -- foreign import declarations next.
+ tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
+ tcExtendGlobalValEnv fo_ids $
-- Value declarations next.
-- We also typecheck any extra binds that came out of the "deriving" process
- -- Nota bene
- tcTopBindsAndThen
- e3
- (\ binds1 (binds2, thing) -> (binds1 `ThenBinds` binds2, thing))
- (valdecls `ThenBinds` extra_deriv_binds)
- (\ e4 ->
- -- Second pass over instance declarations,
+ 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 e4 full_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
- tcClassDecls2 e4 class_info `thenNF_Tc` \ (lie_clasdecls, class_binds) ->
- returnTc ( (EmptyBinds, (inst_binds, class_binds, e4)),
- lie_instdecls `plusLIE` lie_clasdecls,
- () )
+ 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) ->
+
+
+ -- 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 ->
+
+ -- Check that Main defines main
+ (if mod_name == mAIN_Name then
+ tcLookupValueMaybe main_NAME `thenNF_Tc` \ maybe_main ->
+ checkTc (maybeToBool maybe_main) noMainErr
+ else
+ returnTc ()
+ ) `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
+ 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' ->
+
+ let
+ thin_air_ids = map (explicitLookupValueByKey really_final_env . nameUnique) thinAirIdNames
+ -- When looking up the thin-air names we must use
+ -- a global env that includes the zonked locally-defined Ids too
+ -- Hence using really_final_env
+ in
+ 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,
+ tc_thinair = thin_air_ids
+ }))
)
- `thenTc` \ ((val_binds, (inst_binds, class_binds, e4)), lie_alldecls, _) ->
+ -- End of outer fix loop
+ ) `thenTc` \ (final_env, stuff) ->
+ returnTc stuff
- -- 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 (unMkLIE lie_alldecls) `thenTc` \ const_inst_binds ->
-
- -- 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.
-
- applyTcSubstToBinds val_binds `thenNF_Tc` \ val_binds' ->
- applyTcSubstToBinds inst_binds `thenNF_Tc` \ inst_binds' ->
- applyTcSubstToBinds class_binds `thenNF_Tc` \ class_binds' ->
-
- -- ToDo: probably need to back-substitute over all
- -- stuff in 'e4'; we do so here over the Ids,
- -- which is probably enough. WDP 95/06
- mapNF_Tc applyTcSubstToId (getE_GlobalVals e4)
- `thenNF_Tc` \ if_global_ids ->
-
- -- FINISHED AT LAST
- returnTc (
- (class_binds', inst_binds', val_binds', const_inst_binds),
-
- -- the next collection is just for mkInterface
- (fixities, if_global_ids, ce_here, tce_here, full_inst_info),
-
- tycon_specs,
+get_val_decls decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
+\end{code}
---UNUSED: e4,
- -- and... TCE needed for code generation; rest needed for interpreter.
- -- ToDo: still wrong: needs isLocallyDeclared run over everything
- mkE tce_here {-gve_here lve-} ce_here,
- -- NB: interpreter would probably need the gve_here stuff
- ddump_deriv
- )))
+\begin{code}
+noMainErr
+ = hsep [ptext SLIT("Module"), quotes (pprModuleName mAIN_Name),
+ ptext SLIT("must include a definition for"), quotes (ppr main_NAME)]
\end{code}
+