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 ( HsModule(..), HsBinds(..), MonoBinds(..), HsDecl(..) )
16 import HsTypes ( toHsType )
17 import RnHsSyn ( RenamedHsModule, RenamedHsDecl )
18 import TcHsSyn ( TypecheckedMonoBinds,
19 TypecheckedForeignDecl, TypecheckedRuleDecl,
20 zonkTopBinds, zonkForeignExports, zonkRules
24 import Inst ( emptyLIE, plusLIE )
25 import TcBinds ( tcTopBinds )
26 import TcClassDcl ( tcClassDecls2, mkImplicitClassBinds )
27 import TcDefaults ( tcDefaults )
28 import TcEnv ( TcEnv, 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 InstEnv ( InstInfo(..) )
37 import TcSimplify ( tcSimplifyTop )
38 import TcTyClsDecls ( tcTyAndClassDecls )
39 import TcTyDecls ( mkImplicitDataBinds )
41 import CoreUnfold ( unfoldingTemplate )
42 import Type ( funResultTy, splitForAllTys )
43 import Bag ( isEmptyBag )
44 import ErrUtils ( printErrorsAndWarnings, dumpIfSet_dyn )
45 import Id ( idType, idName, idUnfolding )
46 import Module ( Module, moduleName, plusModuleEnv )
47 import Name ( nameOccName, isLocallyDefined, isGlobalName,
48 toRdrName, nameEnvElts, emptyNameEnv
50 import TyCon ( TyCon, isDataTyCon, tyConName, tyConGenInfo )
51 import OccName ( isSysOcc )
52 import TyCon ( TyCon, isClassTyCon )
53 import Class ( Class )
54 import PrelNames ( mAIN_Name, mainName )
55 import UniqSupply ( UniqSupply )
56 import Maybes ( maybeToBool )
58 import BasicTypes ( EP(..) )
59 import Bag ( Bag, isEmptyBag )
61 import HscTypes ( PersistentCompilerState(..), HomeSymbolTable,
62 PackageSymbolTable, DFunId,
63 TypeEnv, extendTypeEnv,
64 TyThing(..), groupTyThings )
65 import FiniteMap ( FiniteMap, delFromFM, lookupWithDefaultFM )
68 Outside-world interface:
71 -- Convenient type synonyms first:
74 tc_pcs :: PersistentCompilerState, -- Augmented with imported information,
75 -- (but not stuff from this module)
76 tc_env :: TypeEnv, -- The TypeEnv just for the stuff from this module
77 tc_insts :: [DFunId], -- Instances, just for this module
78 tc_binds :: TypecheckedMonoBinds,
79 tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports.
80 tc_rules :: [TypecheckedRuleDecl] -- Transformation rules
87 -> PersistentCompilerState
92 -> IO (Maybe (TcEnv, TcResults))
94 typecheckModule dflags this_mod pcs hst hit pit (HsModule mod_name _ _ _ decls _ src_loc)
95 = do env <- initTcEnv global_symbol_table
96 (maybe_result, (errs,warns)) <- initTc dflags env src_loc tc_module
97 printErrorsAndWarnings (errs,warns)
98 printTcDump dflags maybe_result
99 if isEmptyBag errs then
104 global_symbol_table = pcs_PST pcs `plusModuleEnv` hst
106 tc_module = fixTc (\ ~(unf_env ,_)
107 -> tcModule pcs hst get_fixity this_mod decls unf_env)
109 get_fixity :: Name -> Maybe Fixity
111 = case lookupFixityEnv hit nm of
113 Nothing -> lookupFixityEnv pit nm
116 The internal monster:
118 tcModule :: PersistentCompilerState
120 -> (Name -> Maybe Fixity)
123 -> TcEnv -- The knot-tied environment
124 -> TcM (TcEnv, TcResults)
126 -- (unf_env :: TcEnv) is used for type-checking interface pragmas
127 -- which is done lazily [ie failure just drops the pragma
128 -- without having any global-failure effect].
130 -- unf_env is also used to get the pragama info
131 -- for imported dfuns and default methods
133 tcModule pcs hst get_fixity this_mod decls unf_env
134 = -- Type-check the type and class decls
135 tcTyAndClassDecls unf_env decls `thenTc` \ env ->
138 classes = tcEnvClasses env
139 tycons = tcEnvTyCons env -- INCLUDES tycons derived from classes
140 local_classes = filter isLocallyDefined classes
141 local_tycons = [ tc | tc <- tycons,
143 not (isClassTyCon tc)
145 -- For local_tycons, filter out the ones derived from classes
146 -- Otherwise the latter show up in interface files
149 -- Typecheck the instance decls, includes deriving
150 tcInstDecls1 pcs hst unf_env get_fixity this_mod
151 local_tycons decls `thenTc` \ (pcs_with_insts, inst_env, inst_info, deriv_binds) ->
152 tcSetInstEnv inst_env $
154 -- Default declarations
155 tcDefaults decls `thenTc` \ defaulting_tys ->
156 tcSetDefaultTys defaulting_tys $
158 -- Interface type signatures
159 -- We tie a knot so that the Ids read out of interfaces are in scope
160 -- when we read their pragmas.
161 -- What we rely on is that pragmas are typechecked lazily; if
162 -- any type errors are found (ie there's an inconsistency)
163 -- we silently discard the pragma
164 -- We must do this before mkImplicitDataBinds (which comes next), since
165 -- the latter looks up unpackCStringId, for example, which is usually
167 tcInterfaceSigs unf_env decls `thenTc` \ sig_ids ->
168 tcExtendGlobalValEnv sig_ids $
170 -- Create any necessary record selector Ids and their bindings
171 -- "Necessary" includes data and newtype declarations
172 -- We don't create bindings for dictionary constructors;
173 -- they are always fully applied, and the bindings are just there
174 -- to support partial applications
175 mkImplicitDataBinds tycons `thenTc` \ (data_ids, imp_data_binds) ->
176 mkImplicitClassBinds classes `thenNF_Tc` \ (cls_ids, imp_cls_binds) ->
178 -- Extend the global value environment with
180 -- (b) record selectors
181 -- (c) class op selectors
182 -- (d) default-method ids... where? I can't see where these are
183 -- put into the envt, and I'm worried that the zonking phase
184 -- will find they aren't there and complain.
185 tcExtendGlobalValEnv data_ids $
186 tcExtendGlobalValEnv cls_ids $
188 -- Foreign import declarations next
189 tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
190 tcExtendGlobalValEnv fo_ids $
192 -- Value declarations next.
193 -- We also typecheck any extra binds that came out of the "deriving" process
194 tcTopBinds (get_binds decls `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
197 -- Foreign export declarations next
198 tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
200 -- Second pass over class and instance declarations,
201 -- to compile the bindings themselves.
202 tcInstDecls2 inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
203 tcClassDecls2 decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
204 tcRules decls `thenNF_Tc` \ (lie_rules, rules) ->
206 -- Deal with constant or ambiguous InstIds. How could
207 -- there be ambiguous ones? They can only arise if a
208 -- top-level decl falls under the monomorphism
209 -- restriction, and no subsequent decl instantiates its
210 -- type. (Usually, ambiguous type variables are resolved
211 -- during the generalisation step.)
213 lie_alldecls = lie_valdecls `plusLIE`
214 lie_instdecls `plusLIE`
215 lie_clasdecls `plusLIE`
216 lie_fodecls `plusLIE`
219 tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
221 -- Check that Main defines main
222 checkMain this_mod `thenTc_`
224 -- Backsubstitution. This must be done last.
225 -- Even tcSimplifyTop may do some unification.
227 all_binds = imp_data_binds `AndMonoBinds`
228 imp_cls_binds `AndMonoBinds`
229 val_binds `AndMonoBinds`
230 inst_binds `AndMonoBinds`
231 cls_dm_binds `AndMonoBinds`
232 const_inst_binds `AndMonoBinds`
235 zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
237 -- zonkTopBinds puts all the top-level Ids into the tcGEnv
238 zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
239 zonkRules rules `thenNF_Tc` \ rules' ->
242 let groups :: FiniteMap Module TypeEnv
243 groups = groupTyThings (nameEnvElts (getTcGEnv final_env))
245 local_type_env :: TypeEnv
246 local_type_env = lookupWithDefaultFM groups emptyNameEnv this_mod
248 new_pst :: PackageSymbolTable
249 new_pst = extendTypeEnv (pcs_PST pcs) (delFromFM groups this_mod)
251 final_pcs :: PersistentCompilerState
252 final_pcs = pcs_with_insts {pcs_PST = new_pst}
254 returnTc (final_env, -- WAS: really_final_env,
255 TcResults { tc_pcs = final_pcs,
256 tc_env = local_type_env,
257 tc_binds = all_binds',
258 tc_insts = map iDFunId inst_info,
259 tc_fords = foi_decls ++ foe_decls',
263 get_binds decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
268 checkMain :: Module -> TcM ()
270 | moduleName this_mod == mAIN_Name
271 = tcLookupGlobal_maybe mainName `thenNF_Tc` \ maybe_main ->
273 Just (AnId _) -> returnTc ()
274 other -> addErrTc noMainErr
276 | otherwise = returnTc ()
279 = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
280 ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
284 %************************************************************************
286 \subsection{Dumping output}
288 %************************************************************************
291 printTcDump dflags Nothing = return ()
292 printTcDump dflags (Just (_,results))
293 = do dumpIfSet_dyn dflags Opt_D_dump_types
294 "Type signatures" (dump_sigs results)
295 dumpIfSet_dyn dflags Opt_D_dump_tc
296 "Typechecked" (dump_tc results)
299 = vcat [ppr (tc_binds results),
300 pp_rules (tc_rules results) --,
301 -- ppr_gen_tycons (tc_tycons results)
304 dump_sigs results -- Print type signatures
305 = -- Convert to HsType so that we get source-language style printing
306 -- And sort by RdrName
307 vcat $ map ppr_sig $ sortLt lt_sig $
308 [(toRdrName id, toHsType (idType id))
309 | AnId id <- nameEnvElts (tc_env results),
313 lt_sig (n1,_) (n2,_) = n1 < n2
314 ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
316 want_sig id | opt_PprStyle_Debug = True
317 | otherwise = isLocallyDefined n &&
319 not (isSysOcc (nameOccName n))
323 ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
324 vcat (map ppr_gen_tycon (filter isLocallyDefined tcs)),
328 -- x&y are now Id's, not CoreExpr's
330 | Just ep <- tyConGenInfo tycon
331 = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
333 | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
336 = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau),
337 ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
338 ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
341 (_,from_tau) = splitForAllTys (idType from)
344 pp_rules rs = vcat [ptext SLIT("{-# RULES"),
345 nest 4 (vcat (map ppr rs)),