2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcModule]{Typechecking a whole module}
12 #include "HsVersions.h"
14 import CmdLineOpts ( DynFlag(..), DynFlags, opt_PprStyle_Debug )
15 import HsSyn ( HsBinds(..), MonoBinds(..), HsDecl(..) )
16 import HsTypes ( toHsType )
17 import RnHsSyn ( RenamedHsDecl )
18 import TcHsSyn ( TypecheckedMonoBinds,
19 TypecheckedForeignDecl, TypecheckedRuleDecl,
20 zonkTopBinds, zonkForeignExports, zonkRules
24 import Inst ( plusLIE )
25 import TcBinds ( tcTopBinds )
26 import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds )
27 import TcDefaults ( tcDefaults )
28 import TcEnv ( TcEnv, InstInfo(iDFunId), tcExtendGlobalValEnv, tcLookupGlobal_maybe,
29 tcEnvTyCons, tcEnvClasses,
30 tcSetEnv, tcSetInstEnv, initTcEnv, getTcGEnv
32 import TcRules ( tcRules )
33 import TcForeign ( tcForeignImports, tcForeignExports )
34 import TcIfaceSig ( tcInterfaceSigs )
35 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
36 import TcSimplify ( tcSimplifyTop )
37 import TcTyClsDecls ( tcTyAndClassDecls )
38 import TcTyDecls ( mkImplicitDataBinds )
40 import CoreUnfold ( unfoldingTemplate )
41 import Type ( funResultTy, splitForAllTys )
42 import Bag ( isEmptyBag )
43 import ErrUtils ( printErrorsAndWarnings, dumpIfSet_dyn )
44 import Id ( idType, idName, idUnfolding )
45 import Module ( Module, moduleName, plusModuleEnv )
46 import Name ( Name, nameOccName, isLocallyDefined, isGlobalName,
47 toRdrName, nameEnvElts, emptyNameEnv, lookupNameEnv
49 import TyCon ( tyConGenInfo, isClassTyCon )
50 import OccName ( isSysOcc )
51 import PrelNames ( mAIN_Name, mainName )
52 import Maybes ( thenMaybe )
54 import BasicTypes ( EP(..), Fixity )
55 import Bag ( isEmptyBag )
57 import HscTypes ( PersistentCompilerState(..), HomeSymbolTable, HomeIfaceTable,
58 PackageSymbolTable, DFunId, ModIface(..),
59 TypeEnv, extendTypeEnv, lookupTable,
60 TyThing(..), groupTyThings )
61 import FiniteMap ( FiniteMap, delFromFM, lookupWithDefaultFM )
64 Outside-world interface:
67 -- Convenient type synonyms first:
70 tc_pcs :: PersistentCompilerState, -- Augmented with imported information,
71 -- (but not stuff from this module)
73 -- All these fields have info *just for this module*
74 tc_env :: TypeEnv, -- The top level TypeEnv
75 tc_insts :: [DFunId], -- Instances
76 tc_binds :: TypecheckedMonoBinds, -- Bindings
77 tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports.
78 tc_rules :: [TypecheckedRuleDecl] -- Transformation rules
85 -> PersistentCompilerState
86 -> HomeSymbolTable -> HomeIfaceTable
88 -> IO (Maybe TcResults)
90 typecheckModule dflags this_mod pcs hst hit decls
91 = do env <- initTcEnv global_symbol_table
93 (maybe_result, (errs,warns)) <- initTc dflags env tc_module
95 let { maybe_tc_result :: Maybe TcResults ;
96 maybe_tc_result = case maybe_result of
98 Just (_,r) -> Just r }
100 printErrorsAndWarnings (errs,warns)
101 printTcDump dflags maybe_tc_result
103 if isEmptyBag errs then
106 return maybe_tc_result
108 global_symbol_table = pcs_PST pcs `plusModuleEnv` hst
110 tc_module :: TcM (TcEnv, TcResults)
111 tc_module = fixTc (\ ~(unf_env ,_) -> tcModule pcs hst get_fixity this_mod decls unf_env)
115 get_fixity :: Name -> Maybe Fixity
116 get_fixity nm = lookupTable hit pit nm `thenMaybe` \ iface ->
117 lookupNameEnv (mi_fixities iface) nm
120 The internal monster:
122 tcModule :: PersistentCompilerState
124 -> (Name -> Maybe Fixity)
127 -> TcEnv -- The knot-tied environment
128 -> TcM (TcEnv, TcResults)
130 -- (unf_env :: TcEnv) is used for type-checking interface pragmas
131 -- which is done lazily [ie failure just drops the pragma
132 -- without having any global-failure effect].
134 -- unf_env is also used to get the pragama info
135 -- for imported dfuns and default methods
137 tcModule pcs hst get_fixity this_mod decls unf_env
138 = -- Type-check the type and class decls
139 tcTyAndClassDecls unf_env decls `thenTc` \ env ->
142 classes = tcEnvClasses env
143 tycons = tcEnvTyCons env -- INCLUDES tycons derived from classes
144 local_tycons = [ tc | tc <- tycons,
146 not (isClassTyCon tc)
148 -- For local_tycons, filter out the ones derived from classes
149 -- Otherwise the latter show up in interface files
152 -- Typecheck the instance decls, includes deriving
153 tcInstDecls1 (pcs_insts pcs) (pcs_PRS pcs)
154 hst unf_env get_fixity this_mod
155 local_tycons decls `thenTc` \ (new_pcs_insts, inst_env, local_inst_info, deriv_binds) ->
156 tcSetInstEnv inst_env $
158 -- Default declarations
159 tcDefaults decls `thenTc` \ defaulting_tys ->
160 tcSetDefaultTys defaulting_tys $
162 -- Interface type signatures
163 -- We tie a knot so that the Ids read out of interfaces are in scope
164 -- when we read their pragmas.
165 -- What we rely on is that pragmas are typechecked lazily; if
166 -- any type errors are found (ie there's an inconsistency)
167 -- we silently discard the pragma
168 -- We must do this before mkImplicitDataBinds (which comes next), since
169 -- the latter looks up unpackCStringId, for example, which is usually
171 tcInterfaceSigs unf_env decls `thenTc` \ sig_ids ->
172 tcExtendGlobalValEnv sig_ids $
174 -- Create any necessary record selector Ids and their bindings
175 -- "Necessary" includes data and newtype declarations
176 -- We don't create bindings for dictionary constructors;
177 -- they are always fully applied, and the bindings are just there
178 -- to support partial applications
179 mkImplicitDataBinds tycons `thenTc` \ (data_ids, imp_data_binds) ->
180 mkImplicitClassBinds classes `thenNF_Tc` \ (cls_ids, imp_cls_binds) ->
182 -- Extend the global value environment with
184 -- (b) record selectors
185 -- (c) class op selectors
186 -- (d) default-method ids... where? I can't see where these are
187 -- put into the envt, and I'm worried that the zonking phase
188 -- will find they aren't there and complain.
189 tcExtendGlobalValEnv data_ids $
190 tcExtendGlobalValEnv cls_ids $
192 -- Foreign import declarations next
193 tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
194 tcExtendGlobalValEnv fo_ids $
196 -- Value declarations next.
197 -- We also typecheck any extra binds that came out of the "deriving" process
198 tcTopBinds (get_binds decls `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
201 -- Foreign export declarations next
202 tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
204 -- Second pass over class and instance declarations,
205 -- to compile the bindings themselves.
206 tcInstDecls2 local_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
207 tcClassDecls2 decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
208 tcRules (pcs_rules pcs) this_mod decls `thenNF_Tc` \ (new_pcs_rules, lie_rules, local_rules) ->
210 -- Deal with constant or ambiguous InstIds. How could
211 -- there be ambiguous ones? They can only arise if a
212 -- top-level decl falls under the monomorphism
213 -- restriction, and no subsequent decl instantiates its
214 -- type. (Usually, ambiguous type variables are resolved
215 -- during the generalisation step.)
217 lie_alldecls = lie_valdecls `plusLIE`
218 lie_instdecls `plusLIE`
219 lie_clasdecls `plusLIE`
220 lie_fodecls `plusLIE`
223 tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
225 -- Check that Main defines main
226 checkMain this_mod `thenTc_`
228 -- Backsubstitution. This must be done last.
229 -- Even tcSimplifyTop may do some unification.
231 all_binds = imp_data_binds `AndMonoBinds`
232 imp_cls_binds `AndMonoBinds`
233 val_binds `AndMonoBinds`
234 inst_binds `AndMonoBinds`
235 cls_dm_binds `AndMonoBinds`
236 const_inst_binds `AndMonoBinds`
239 zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
241 -- zonkTopBinds puts all the top-level Ids into the tcGEnv
242 zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
243 zonkRules local_rules `thenNF_Tc` \ local_rules' ->
246 let groups :: FiniteMap Module TypeEnv
247 groups = groupTyThings (nameEnvElts (getTcGEnv final_env))
249 local_type_env :: TypeEnv
250 local_type_env = lookupWithDefaultFM groups emptyNameEnv this_mod
252 new_pst :: PackageSymbolTable
253 new_pst = extendTypeEnv (pcs_PST pcs) (delFromFM groups this_mod)
255 final_pcs :: PersistentCompilerState
256 final_pcs = pcs { pcs_PST = new_pst,
257 pcs_insts = new_pcs_insts,
258 pcs_rules = new_pcs_rules
262 TcResults { tc_pcs = final_pcs,
263 tc_env = local_type_env,
264 tc_binds = all_binds',
265 tc_insts = map iDFunId local_inst_info,
266 tc_fords = foi_decls ++ foe_decls',
267 tc_rules = local_rules'
270 get_binds decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
275 checkMain :: Module -> TcM ()
277 | moduleName this_mod == mAIN_Name
278 = tcLookupGlobal_maybe mainName `thenNF_Tc` \ maybe_main ->
280 Just (AnId _) -> returnTc ()
281 other -> addErrTc noMainErr
283 | otherwise = returnTc ()
286 = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
287 ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
291 %************************************************************************
293 \subsection{Dumping output}
295 %************************************************************************
298 printTcDump dflags Nothing = return ()
299 printTcDump dflags (Just results)
300 = do dumpIfSet_dyn dflags Opt_D_dump_types
301 "Type signatures" (dump_sigs results)
302 dumpIfSet_dyn dflags Opt_D_dump_tc
303 "Typechecked" (dump_tc results)
306 = vcat [ppr (tc_binds results),
307 pp_rules (tc_rules results),
308 ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)]
311 dump_sigs results -- Print type signatures
312 = -- Convert to HsType so that we get source-language style printing
313 -- And sort by RdrName
314 vcat $ map ppr_sig $ sortLt lt_sig $
315 [(toRdrName id, toHsType (idType id))
316 | AnId id <- nameEnvElts (tc_env results),
320 lt_sig (n1,_) (n2,_) = n1 < n2
321 ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
323 want_sig id | opt_PprStyle_Debug = True
324 | otherwise = isLocallyDefined n &&
326 not (isSysOcc (nameOccName n))
330 ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
331 vcat (map ppr_gen_tycon (filter isLocallyDefined tcs)),
335 -- x&y are now Id's, not CoreExpr's
337 | Just ep <- tyConGenInfo tycon
338 = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
340 | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
343 = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau),
344 ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
345 ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
348 (_,from_tau) = splitForAllTys (idType from)
351 pp_rules rs = vcat [ptext SLIT("{-# RULES"),
352 nest 4 (vcat (map ppr rs)),