\begin{code}
module TcModule (
- typecheckModule,
+ typecheckModule, typecheckIface, typecheckStmt, 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 HsTypes ( toHsType )
-import RnHsSyn ( RenamedHsModule )
-import TcHsSyn ( TcMonoBinds, TypecheckedMonoBinds,
+import CmdLineOpts ( DynFlag(..), DynFlags, dopt )
+import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..), HsExpr(..),
+ Stmt(..), InPat(..), HsMatchContext(..), HsDoContext(..), RuleDecl(..),
+ isIfaceRuleDecl, nullBinds, andMonoBindList, mkSimpleMatch, placeHolderType
+ )
+import PrelNames ( mAIN_Name, mainName, ioTyConName, printName,
+ returnIOName, bindIOName, failIOName,
+ itName
+ )
+import MkId ( unsafeCoerceId )
+import RnHsSyn ( RenamedHsBinds, RenamedHsDecl, RenamedStmt,
+ RenamedHsExpr )
+import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr,
TypecheckedForeignDecl, TypecheckedRuleDecl,
- zonkTopBinds, zonkForeignExports, zonkRules
+ zonkTopBinds, zonkForeignExports, zonkRules, mkHsLet,
+ zonkExpr, zonkIdBndr
)
+import MkIface ( pprModDetails )
+import TcExpr ( tcMonoExpr )
import TcMonad
-import Inst ( Inst, emptyLIE, plusLIE )
-import TcBinds ( tcTopBindsAndThen )
-import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds )
-import TcDefaults ( tcDefaults )
-import TcEnv ( tcExtendGlobalValEnv, tcExtendTypeEnv,
- getEnvTyCons, getEnvClasses, tcLookupValueByKeyMaybe,
- tcSetValueEnv, tcSetInstEnv,
- initEnv,
- ValueEnv,
+import TcMType ( unifyTauTy, newTyVarTy, zonkTcType, tcInstType )
+import TcType ( Type, liftedTypeKind, openTypeKind,
+ tyVarsOfType, tidyType, tcFunResultTy,
+ mkForAllTys, mkFunTys, mkTyConApp, tcSplitForAllTys
+ )
+import TcMatches ( tcStmtsAndThen )
+import Inst ( emptyLIE, plusLIE )
+import TcBinds ( tcTopBinds )
+import TcClassDcl ( tcClassDecls2 )
+import TcDefaults ( tcDefaults, defaultDefaultTys )
+import TcEnv ( TcEnv, RecTcEnv, InstInfo(iDFunId), tcExtendGlobalValEnv, tcLookup_maybe,
+ isLocalThing, tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv,
+ tcExtendGlobalTypeEnv, tcLookupGlobalId, tcLookupTyCon,
+ TcTyThing(..), tcLookupId
)
-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, TcKind )
-
-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 Util
-import Bag ( Bag, isEmptyBag )
+import CoreUnfold ( unfoldingTemplate, hasUnfolding )
+import TysWiredIn ( mkListTy, unitTy )
+import ErrUtils ( printErrorsAndWarnings, errorsFound,
+ dumpIfSet_dyn, dumpIfSet_dyn_or, showPass )
+import Id ( Id, idType, idUnfolding )
+import Module ( Module, moduleName )
+import Name ( Name )
+import NameEnv ( nameEnvElts, lookupNameEnv )
+import TyCon ( tyConGenInfo )
+import BasicTypes ( EP(..), Fixity, RecFlag(..) )
+import SrcLoc ( noSrcLoc )
import Outputable
+import IO ( stdout )
+import HscTypes ( PersistentCompilerState(..), HomeSymbolTable,
+ PackageTypeEnv, ModIface(..),
+ ModDetails(..), DFunId,
+ TypeEnv, extendTypeEnvList,
+ TyThing(..), implicitTyThingIds,
+ mkTypeEnv
+ )
+\end{code}
+
+
+%************************************************************************
+%* *
+\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 $
+
+ -- 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 iface_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 $
+ tcExtendGlobalTypeEnv ic_type_env $
+
+ -- 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")
+
+ where
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity n = pprPanic "typecheckStmt" (ppr n)
+\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
+ combine stmt (ids, stmts) = (ids, stmt:stmts)
+\end{code}
+
+%************************************************************************
+%* *
+\subsection{Typechecking an expression}
+%* *
+%************************************************************************
+
+\begin{code}
+typecheckExpr :: DynFlags
+ -> 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,
+ [Id], -- always empty (matches typecheckStmt)
+ Type))
+
+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 $
+
+ -- 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 $
+ 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 $
+ 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 ->
+ ioToTc (dumpIfSet_dyn dflags
+ Opt_D_dump_tc "Typechecked" (ppr zonked_expr)) `thenNF_Tc_`
+ 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}
-Outside-world interface:
+%************************************************************************
+%* *
+\subsection{Typechecking a module}
+%* *
+%************************************************************************
+
\begin{code}
+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)
--- 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.
+ -- 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_env :: ValueEnv
+ tc_binds :: TypecheckedMonoBinds, -- Bindings
+ tc_fords :: [TypecheckedForeignDecl] -- Foreign import & exports.
}
----------------
-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)
-
-dump_tc results
- = ppr (tc_binds results) $$ pp_rules (tc_rules 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)) | id <- nameEnvElts (tc_env results),
- want_sig id
- ]
+
+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 unqual maybe_tc_result
+ ; return maybe_tc_result }
where
- lt_sig (n1,_) (n2,_) = n1 < n2
- ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
-
- want_sig id | opt_PprStyle_Debug = True
- | otherwise = isLocallyDefined n && not (isSysOcc (nameOccName n))
- where
- n = idName id
-
-pp_rules [] = empty
-pp_rules rs = vcat [ptext SLIT("{-# RULES"),
- nest 4 (vcat (map ppr rs)),
- ptext SLIT("#-}")]
-\end{code}
+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
-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 $
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
- 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 $
-
- -- 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) ->
- tcExtendGlobalValEnv fo_ids $
- -- 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 $
+tcModule :: PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (PersistentCompilerState, TcResults)
- -- foreign export declarations next.
- tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
+tcModule pcs hst get_fixity this_mod decls
+ = 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
- -- 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) ->
+ -- 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
+ 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) ->
+
+ -- CHECK THAT main IS DEFINED WITH RIGHT TYPE, IF REQUIRED
+ traceTc (text "Tc6") `thenNF_Tc_`
+ tcCheckMain this_mod `thenTc_`
-- Deal with constant or ambiguous InstIds. How could
-- there be ambiguous ones? They can only arise if a
-- 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_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
- tcLookupValueByKeyMaybe mainKey `thenNF_Tc` \ maybe_main ->
- checkTc (maybeToBool maybe_main) noMainErr
- else
- returnTc ()
- ) `thenTc_`
-
+ 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 = 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_insts = map iDFunId local_insts,
+ 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}
+
+
+%************************************************************************
+%* *
+\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 $
+ tcIfaceImports pcs hst get_fixity this_mod decls
+ ; printIfaceDump dflags maybe_tc_stuff
+ ; return maybe_tc_stuff }
+ 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
+
+ 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))
+
+ mod_details = ModDetails { md_types = mkTypeEnv local_things,
+ md_insts = map iDFunId local_inst_info,
+ md_rules = [(id,rule) | IfaceRuleOut id rule <- local_rules],
+ md_binds = [] }
+ -- All the rules from an interface are of the IfaceRuleOut form
+ in
+ returnTc (new_pcs, mod_details)
+
+tcImports :: RecTcEnv
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (TcEnv, PersistentCompilerState, [InstInfo],
+ RenamedHsBinds, [TypecheckedRuleDecl])
+
+-- tcImports is a slight mis-nomer.
+-- It deals with everything that could be an import:
+-- type and class decls
+-- interface signatures (checked lazily)
+-- 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 this_mod 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
+ = filter (not . isLocalThing this_mod) 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{Interfacing the Tc monad to the IO monad}
+%* *
+%************************************************************************
+
\begin{code}
-noMainErr
- = hsep [ptext SLIT("Module"), quotes (pprModuleName mAIN_Name),
- ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
+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}
+
+%************************************************************************
+%* *
+\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 [tc | ATyCon tc <- nameEnvElts (tc_env results)]
+ else
+ empty
+ ]
+
+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),
+ 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 (tcFunResultTy from_tau),
+ ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
+ ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
+ ]
+ where
+ (_,from_tau) = tcSplitForAllTys (idType from)
+\end{code}
projects / ghc-hetmet.git / blobdiff