\begin{code}
module TcModule (
- typecheckModule,
- TcResults(..)
+ typecheckModule, typecheckIface, typecheckExpr, TcResults(..)
) where
#include "HsVersions.h"
import CmdLineOpts ( DynFlag(..), DynFlags, opt_PprStyle_Debug )
-import HsSyn ( HsModule(..), HsBinds(..), MonoBinds(..), HsDecl(..) )
+import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..), HsExpr(..),
+ isIfaceRuleDecl, nullBinds, andMonoBindList
+ )
import HsTypes ( toHsType )
-import RnHsSyn ( RenamedHsModule, RenamedHsDecl )
-import TcHsSyn ( TypecheckedMonoBinds,
+import PrelNames ( SyntaxMap, mAIN_Name, mainName, ioTyConName, printName )
+import RnHsSyn ( RenamedHsBinds, RenamedHsDecl, RenamedHsExpr )
+import TcHsSyn ( TypecheckedMonoBinds, TypecheckedHsExpr,
TypecheckedForeignDecl, TypecheckedRuleDecl,
- zonkTopBinds, zonkForeignExports, zonkRules
+ zonkTopBinds, zonkForeignExports, zonkRules, mkHsLet,
+ zonkExpr
)
+
import TcMonad
+import TcType ( newTyVarTy, zonkTcType, tcInstType )
+import TcUnify ( unifyTauTy )
import Inst ( plusLIE )
+import VarSet ( varSetElems )
import TcBinds ( tcTopBinds )
-import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds )
-import TcDefaults ( tcDefaults )
-import TcEnv ( TcEnv, tcExtendGlobalValEnv, tcLookupGlobal_maybe,
- tcEnvTyCons, tcEnvClasses,
- tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv
+import TcClassDcl ( tcClassDecls2 )
+import TcDefaults ( tcDefaults, defaultDefaultTys )
+import TcExpr ( tcMonoExpr )
+import TcEnv ( TcEnv, RecTcEnv, InstInfo, tcExtendGlobalValEnv, tcLookup_maybe,
+ isLocalThing, tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv,
+ TcTyThing(..), tcLookupTyCon
)
-import TcRules ( tcRules )
+import TcRules ( tcIfaceRules, tcSourceRules )
import TcForeign ( tcForeignImports, tcForeignExports )
import TcIfaceSig ( tcInterfaceSigs )
import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
-import InstEnv ( InstInfo(..) )
-import TcSimplify ( tcSimplifyTop )
+import TcSimplify ( tcSimplifyTop, tcSimplifyInfer )
import TcTyClsDecls ( tcTyAndClassDecls )
-import TcTyDecls ( mkImplicitDataBinds )
-
-import CoreUnfold ( unfoldingTemplate )
-import Type ( funResultTy, splitForAllTys )
-import Bag ( isEmptyBag )
-import ErrUtils ( printErrorsAndWarnings, dumpIfSet_dyn )
-import Id ( idType, idName, idUnfolding )
-import Module ( Module, moduleName, plusModuleEnv )
-import Name ( Name, nameOccName, isLocallyDefined, isGlobalName,
- toRdrName, nameEnvElts, emptyNameEnv, lookupNameEnv
- )
-import TyCon ( tyConGenInfo, isClassTyCon )
-import OccName ( isSysOcc )
-import PrelNames ( mAIN_Name, mainName )
-import Maybes ( thenMaybe )
+
+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 BasicTypes ( EP(..), Fixity )
-import Bag ( isEmptyBag )
import Outputable
-import HscTypes ( PersistentCompilerState(..), HomeSymbolTable, HomeIfaceTable,
- PackageSymbolTable, PackageIfaceTable, DFunId, ModIface(..),
- TypeEnv, extendTypeEnv, lookupTable,
- TyThing(..), groupTyThings )
-import FiniteMap ( FiniteMap, delFromFM, lookupWithDefaultFM )
+import HscTypes ( PersistentCompilerState(..), HomeSymbolTable,
+ PackageTypeEnv, ModIface(..),
+ TypeEnv, extendTypeEnvList,
+ TyThing(..), implicitTyThingIds,
+ mkTypeEnv
+ )
\end{code}
Outside-world interface:
-- Convenient type synonyms first:
data TcResults
= TcResults {
- tc_pcs :: PersistentCompilerState, -- Augmented with imported information,
- -- (but not stuff from this module)
- tc_env :: TypeEnv, -- The TypeEnv just for the stuff from this module
- tc_insts :: [DFunId], -- Instances, just for this module
- tc_binds :: TypecheckedMonoBinds,
+ -- 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
- -> Module
-> PersistentCompilerState
-> HomeSymbolTable
- -> HomeIfaceTable
- -> PackageIfaceTable
- -> RenamedHsModule
- -> IO (Maybe (TcEnv, TcResults))
-
-typecheckModule dflags this_mod pcs hst hit pit (HsModule mod_name _ _ _ decls _ src_loc)
- = do env <- initTcEnv global_symbol_table
- (maybe_result, (errs,warns)) <- initTc dflags env src_loc tc_module
- printErrorsAndWarnings (errs,warns)
- printTcDump dflags maybe_result
- if isEmptyBag errs then
- return Nothing
- else
- return maybe_result
+ -> ModIface -- Iface for this module (just module & fixities)
+ -> PrintUnqualified -- For error printing
+ -> (SyntaxMap, [RenamedHsDecl])
+ -> IO (Maybe (PersistentCompilerState, TcResults))
+ -- The new PCS is Augmented with imported information,
+ -- (but not stuff from this module)
+
+
+typecheckModule dflags pcs hst mod_iface unqual (syn_map, decls)
+ = do { maybe_tc_result <- typecheck dflags syn_map pcs hst unqual $
+ tcModule pcs hst get_fixity this_mod decls
+ ; printTcDump dflags maybe_tc_result
+ ; return maybe_tc_result }
where
- global_symbol_table = pcs_PST pcs `plusModuleEnv` hst
+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
+
+---------------
+typecheckIface
+ :: DynFlags
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> ModIface -- Iface for this module (just module & fixities)
+ -> (SyntaxMap, [RenamedHsDecl])
+ -> IO (Maybe (PersistentCompilerState, TypeEnv, [TypecheckedRuleDecl]))
+ -- The new PCS is Augmented with imported information,
+ -- (but not stuff from this module).
+ -- The TcResults returned contains only the environment
+ -- and rules.
+
+
+typecheckIface dflags pcs hst mod_iface (syn_map, decls)
+ = do { maybe_tc_stuff <- typecheck dflags syn_map pcs hst alwaysQualify $
+ tcIfaceImports pcs hst get_fixity this_mod decls
+ ; printIfaceDump dflags maybe_tc_stuff
+ ; return maybe_tc_stuff }
+ where
+ this_mod = mi_module mod_iface
+ fixity_env = mi_fixities mod_iface
+
+ get_fixity :: Name -> Maybe Fixity
+ get_fixity nm = lookupNameEnv fixity_env nm
- tc_module = fixTc (\ ~(unf_env ,_)
- -> tcModule pcs hst get_fixity this_mod decls unf_env)
+ tcIfaceImports pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _, _, _) ->
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ ) `thenTc` \ (env, new_pcs, local_inst_info,
+ deriv_binds, local_rules) ->
+ ASSERT(nullBinds deriv_binds)
+ let
+ local_things = filter (isLocalThing this_mod)
+ (nameEnvElts (getTcGEnv env))
+ local_type_env :: TypeEnv
+ local_type_env = mkTypeEnv local_things
+ in
+ -- throw away local_inst_info
+ returnTc (new_pcs, local_type_env, local_rules)
+
+---------------
+typecheckExpr :: DynFlags
+ -> Bool -- True <=> wrap in 'print' to get a result of IO type
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> PrintUnqualified -- For error printing
+ -> Module
+ -> (SyntaxMap,
+ RenamedHsExpr, -- The expression itself
+ [RenamedHsDecl]) -- Plus extra decls it sucked in from interface files
+ -> IO (Maybe (PersistentCompilerState, TypecheckedHsExpr, TcType))
+
+typecheckExpr dflags wrap_io pcs hst unqual this_mod (syn_map, expr, decls)
+ = typecheck dflags syn_map pcs hst unqual $
+
+ -- use the default default settings, i.e. [Integer, Double]
+ tcSetDefaultTys defaultDefaultTys $
+
+ -- Typecheck the extra declarations
+ fixTc (\ ~(unf_env, _, _, _, _) ->
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ ) `thenTc` \ (env, new_pcs, local_inst_info, deriv_binds, local_rules) ->
+ ASSERT( null local_inst_info && nullBinds deriv_binds && null local_rules )
+
+ -- Now typecheck the expression
+ tcSetEnv env $
+ tc_expr expr `thenTc` \ (expr', expr_ty) ->
+ zonkExpr expr' `thenNF_Tc` \ zonked_expr ->
+ zonkTcType expr_ty `thenNF_Tc` \ zonked_ty ->
+ ioToTc (dumpIfSet_dyn dflags
+ Opt_D_dump_tc "Typechecked" (ppr zonked_expr)) `thenNF_Tc_`
+ returnTc (new_pcs, zonked_expr, zonked_ty)
+
+ where
get_fixity :: Name -> Maybe Fixity
- get_fixity nm = lookupTable hit pit nm `thenMaybe` \ iface ->
- lookupNameEnv (mi_fixities iface) nm
+ get_fixity n = pprPanic "typecheckExpr" (ppr n)
+
+ smpl_doc = ptext SLIT("main expression")
+
+ -- Typecheck it, wrapping in 'print' if necessary to
+ -- get a result of type IO t. Returns the result type
+ -- that is free in the result type
+ tc_expr e
+ | wrap_io = tryTc_ (tc_io_expr (HsApp (HsVar printName) e)) -- Recovery case
+ (tc_io_expr e) -- Main case
+ | otherwise = newTyVarTy openTypeKind `thenTc` \ ty ->
+ tcMonoExpr e ty `thenTc` \ (e', lie) ->
+ tcSimplifyInfer smpl_doc (varSetElems (tyVarsOfType ty)) lie
+ `thenTc` \ (qtvs, lie_free, dict_binds, dict_ids) ->
+ tcSimplifyTop lie_free `thenTc` \ const_binds ->
+ let all_expr = mkHsLet const_binds $
+ TyLam qtvs $
+ DictLam dict_ids $
+ mkHsLet dict_binds $
+ e'
+ all_expr_ty = mkForAllTys qtvs $
+ mkFunTys (map idType dict_ids) $
+ ty
+ in
+ returnTc (all_expr, all_expr_ty)
+ where
+ tc_io_expr e = newTyVarTy openTypeKind `thenTc` \ ty ->
+ tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon ->
+ let
+ res_ty = mkTyConApp ioTyCon [ty]
+ in
+ tcMonoExpr e res_ty `thenTc` \ (e', lie) ->
+ tcSimplifyTop lie `thenTc` \ const_binds ->
+ let all_expr = mkHsLet const_binds e' in
+ returnTc (all_expr, res_ty)
+
+---------------
+typecheck :: DynFlags
+ -> SyntaxMap
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> PrintUnqualified -- For error printing
+ -> TcM r
+ -> IO (Maybe r)
+
+typecheck dflags syn_map pcs hst unqual thing_inside
+ = do { showPass dflags "Typechecker";
+ ; env <- initTcEnv syn_map hst (pcs_PTE pcs)
+
+ ; (maybe_tc_result, errs) <- initTc dflags env thing_inside
+
+ ; printErrorsAndWarnings unqual errs
+
+ ; if errorsFound errs then
+ return Nothing
+ else
+ return maybe_tc_result
+ }
\end{code}
The internal monster:
-> (Name -> Maybe Fixity)
-> Module
-> [RenamedHsDecl]
- -> TcEnv -- The knot-tied environment
- -> TcM (TcEnv, TcResults)
-
- -- (unf_env :: TcEnv) 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
-
-tcModule pcs hst get_fixity this_mod decls unf_env
- = -- Type-check the type and class decls
- tcTyAndClassDecls unf_env decls `thenTc` \ env ->
+ -> TcM (PersistentCompilerState, TcResults)
+
+tcModule pcs hst get_fixity this_mod decls
+ = fixTc (\ ~(unf_env, _, _) ->
+ -- Loop back the final environment, including the fully zonkec
+ -- versions of bindings from this module. In the presence of mutual
+ -- recursion, interface type signatures may mention variables defined
+ -- in this module, which is why the knot is so big
+
+ -- Type-check the type and class decls, and all imported decls
+ tcImports unf_env pcs hst get_fixity this_mod decls
+ `thenTc` \ (env, new_pcs, local_insts, deriv_binds, local_rules) ->
+
+ tcSetEnv env $
+
+ -- Foreign import declarations next
+ traceTc (text "Tc4") `thenNF_Tc_`
+ tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
+ tcExtendGlobalValEnv fo_ids $
+
+ -- Default declarations
+ tcDefaults decls `thenTc` \ defaulting_tys ->
+ tcSetDefaultTys defaulting_tys $
+
+ -- Value declarations next.
+ -- We also typecheck any extra binds that came out of the "deriving" process
+ traceTc (text "Default types" <+> ppr defaulting_tys) `thenNF_Tc_`
+ traceTc (text "Tc5") `thenNF_Tc_`
+ tcTopBinds (val_binds `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
+
+ -- Second pass over class and instance declarations,
+ -- plus rules and foreign exports, to generate bindings
+ tcSetEnv env $
+ tcInstDecls2 local_insts `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
+ tcClassDecls2 this_mod tycl_decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
+ tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
+ tcSourceRules source_rules `thenNF_Tc` \ (lie_rules, more_local_rules) ->
+
+ -- Deal with constant or ambiguous InstIds. How could
+ -- there be ambiguous ones? They can only arise if a
+ -- top-level decl falls under the monomorphism
+ -- 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
+ traceTc (text "Tc6") `thenNF_Tc_`
+ tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
+
+ -- 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
+ traceTc (text "Tc7") `thenNF_Tc_`
+ zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
+ tcSetEnv final_env $
+ -- zonkTopBinds puts all the top-level Ids into the tcGEnv
+ traceTc (text "Tc8") `thenNF_Tc_`
+ zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
+ traceTc (text "Tc9") `thenNF_Tc_`
+ zonkRules more_local_rules `thenNF_Tc` \ more_local_rules' ->
+
+
+ let local_things = filter (isLocalThing this_mod) (nameEnvElts (getTcGEnv final_env))
+
+ -- Create any necessary "implicit" bindings (data constructors etc)
+ -- Should we create bindings for dictionary constructors?
+ -- They are always fully applied, and the bindings are just there
+ -- to support partial applications. But it's easier to let them through.
+ implicit_binds = andMonoBindList [ CoreMonoBind id (unfoldingTemplate unf)
+ | id <- implicitTyThingIds local_things
+ , let unf = idUnfolding id
+ , hasUnfolding unf
+ ]
+
+ local_type_env :: TypeEnv
+ local_type_env = mkTypeEnv local_things
+
+ all_local_rules = local_rules ++ more_local_rules'
+ in
+ traceTc (text "Tc10") `thenNF_Tc_`
+ returnTc (final_env,
+ new_pcs,
+ TcResults { tc_env = local_type_env,
+ tc_binds = implicit_binds `AndMonoBinds` all_binds',
+ tc_fords = foi_decls ++ foe_decls',
+ tc_rules = all_local_rules
+ }
+ )
+ ) `thenTc` \ (_, pcs, tc_result) ->
+ returnTc (pcs, tc_result)
+ where
+ tycl_decls = [d | TyClD d <- decls]
+ val_binds = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
+ source_rules = [d | RuleD d <- decls, not (isIfaceRuleDecl d)]
+\end{code}
+
+
+\begin{code}
+tcImports :: RecTcEnv
+ -> PersistentCompilerState
+ -> HomeSymbolTable
+ -> (Name -> Maybe Fixity)
+ -> Module
+ -> [RenamedHsDecl]
+ -> TcM (TcEnv, PersistentCompilerState, [InstInfo],
+ RenamedHsBinds, [TypecheckedRuleDecl])
+
+-- tcImports is a slight mis-nomer.
+-- It deals with everythign that could be an import:
+-- type and class decls
+-- interface signatures
+-- instance decls
+-- rule decls
+-- These can occur in source code too, of course
+
+tcImports unf_env pcs hst get_fixity this_mod decls
+ -- (unf_env :: RecTcEnv) is used for type-checking interface pragmas
+ -- which is done lazily [ie failure just drops the pragma
+ -- without having any global-failure effect].
+ --
+ -- unf_env is also used to get the pragama info
+ -- for imported dfuns and default methods
+
+ = checkNoErrsTc $
+ -- tcImports recovers internally, but if anything gave rise to
+ -- an error we'd better stop now, to avoid a cascade
+
+ traceTc (text "Tc1") `thenNF_Tc_`
+ tcTyAndClassDecls unf_env tycl_decls `thenTc` \ env ->
tcSetEnv env $
- let
- classes = tcEnvClasses env
- tycons = tcEnvTyCons env -- INCLUDES tycons derived from classes
- local_tycons = [ tc | tc <- tycons,
- isLocallyDefined tc,
- not (isClassTyCon tc)
- ]
- -- For local_tycons, filter out the ones derived from classes
- -- Otherwise the latter show up in interface files
- in
-- Typecheck the instance decls, includes deriving
- tcInstDecls1 pcs hst unf_env get_fixity this_mod
- local_tycons decls `thenTc` \ (pcs_with_insts, inst_env, inst_info, deriv_binds) ->
+ 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 $
- -- 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 ->
+ traceTc (text "Tc3") `thenNF_Tc_`
+ tcInterfaceSigs unf_env tycl_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
- tcTopBinds (get_binds decls `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
- tcSetEnv env $
- -- Foreign export declarations next
- tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
+ 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
- -- 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) ->
-
- -- 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.)
+ tcGetEnv `thenTc` \ unf_env ->
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 ->
+ all_things = nameEnvElts (getTcGEnv unf_env)
- -- Check that Main defines main
- checkMain this_mod `thenTc_`
+ -- 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
- -- 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
+ 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
- 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 rules `thenNF_Tc` \ rules' ->
-
-
- let groups :: FiniteMap Module TypeEnv
- groups = groupTyThings (nameEnvElts (getTcGEnv final_env))
-
- local_type_env :: TypeEnv
- local_type_env = lookupWithDefaultFM groups emptyNameEnv this_mod
-
- new_pst :: PackageSymbolTable
- new_pst = extendTypeEnv (pcs_PST pcs) (delFromFM groups this_mod)
-
- final_pcs :: PersistentCompilerState
- final_pcs = pcs_with_insts {pcs_PST = new_pst}
- in
- returnTc (final_env, -- WAS: really_final_env,
- TcResults { tc_pcs = final_pcs,
- tc_env = local_type_env,
- tc_binds = all_binds',
- tc_insts = map iDFunId inst_info,
- tc_fords = foi_decls ++ foe_decls',
- tc_rules = rules'
- })
-
-get_binds decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
-\end{code}
+ 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}
-checkMain :: Module -> TcM ()
-checkMain this_mod
- | moduleName this_mod == mAIN_Name
- = tcLookupGlobal_maybe mainName `thenNF_Tc` \ maybe_main ->
- case maybe_main of
- Just (AnId _) -> returnTc ()
- other -> addErrTc noMainErr
-
- | otherwise = returnTc ()
-
-noMainErr
- = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
- ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
+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}
\begin{code}
printTcDump dflags Nothing = return ()
-printTcDump dflags (Just (_,results))
+printTcDump dflags (Just (_, results))
= do dumpIfSet_dyn dflags Opt_D_dump_types
- "Type signatures" (dump_sigs results)
+ "Type signatures" (dump_sigs (tc_env results))
dumpIfSet_dyn dflags Opt_D_dump_tc
"Typechecked" (dump_tc results)
+printIfaceDump dflags Nothing = return ()
+printIfaceDump dflags (Just (_, env, rules))
+ = do dumpIfSet_dyn dflags Opt_D_dump_types
+ "Type signatures" (dump_sigs env)
+ dumpIfSet_dyn dflags Opt_D_dump_tc
+ "Typechecked" (dump_iface env rules)
+
dump_tc results
= vcat [ppr (tc_binds results),
pp_rules (tc_rules results),
ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)]
]
-dump_sigs results -- Print type signatures
+dump_iface env rules
+ = vcat [pp_rules rules,
+ ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts env]
+ ]
+
+dump_sigs env -- Print type signatures
= -- Convert to HsType so that we get source-language style printing
-- And sort by RdrName
vcat $ map ppr_sig $ sortLt lt_sig $
- [(toRdrName id, toHsType (idType id))
- | AnId id <- nameEnvElts (tc_env results),
- want_sig id
+ [ (toRdrName id, toHsType (idType id))
+ | AnId id <- nameEnvElts env,
+ want_sig id
]
where
lt_sig (n1,_) (n2,_) = n1 < n2
ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
want_sig id | opt_PprStyle_Debug = True
- | otherwise = isLocallyDefined n &&
- isGlobalName n &&
- not (isSysOcc (nameOccName n))
- where
- n = idName id
+ | 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 (filter isLocallyDefined tcs)),
+ vcat (map ppr_gen_tycon tcs),
ptext SLIT("#-}")
]