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 ( 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 ( Name, nameOccName, isLocallyDefined, isGlobalName,
48 toRdrName, nameEnvElts, emptyNameEnv, lookupNameEnv
50 import TyCon ( tyConGenInfo, isClassTyCon )
51 import OccName ( isSysOcc )
52 import PrelNames ( mAIN_Name, mainName )
53 import Maybes ( thenMaybe )
55 import BasicTypes ( EP(..), Fixity )
56 import Bag ( isEmptyBag )
58 import HscTypes ( PersistentCompilerState(..), HomeSymbolTable, HomeIfaceTable,
59 PackageSymbolTable, PackageIfaceTable, DFunId, ModIface(..),
60 TypeEnv, extendTypeEnv, lookupTable,
61 TyThing(..), groupTyThings )
62 import FiniteMap ( FiniteMap, delFromFM, lookupWithDefaultFM )
65 Outside-world interface:
68 -- Convenient type synonyms first:
71 tc_pcs :: PersistentCompilerState, -- Augmented with imported information,
72 -- (but not stuff from this module)
73 tc_env :: TypeEnv, -- The TypeEnv just for the stuff from this module
74 tc_insts :: [DFunId], -- Instances, just for this module
75 tc_binds :: TypecheckedMonoBinds,
76 tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports.
77 tc_rules :: [TypecheckedRuleDecl] -- Transformation rules
84 -> PersistentCompilerState
89 -> IO (Maybe (TcEnv, TcResults))
91 typecheckModule dflags this_mod pcs hst hit pit (HsModule mod_name _ _ _ decls _ src_loc)
92 = do env <- initTcEnv global_symbol_table
93 (maybe_result, (errs,warns)) <- initTc dflags env src_loc tc_module
94 printErrorsAndWarnings (errs,warns)
95 printTcDump dflags maybe_result
96 if isEmptyBag errs then
101 global_symbol_table = pcs_PST pcs `plusModuleEnv` hst
103 tc_module = fixTc (\ ~(unf_env ,_)
104 -> tcModule pcs hst get_fixity this_mod decls unf_env)
106 get_fixity :: Name -> Maybe Fixity
107 get_fixity nm = lookupTable hit pit nm `thenMaybe` \ iface ->
108 lookupNameEnv (mi_fixities iface) nm
111 The internal monster:
113 tcModule :: PersistentCompilerState
115 -> (Name -> Maybe Fixity)
118 -> TcEnv -- The knot-tied environment
119 -> TcM (TcEnv, TcResults)
121 -- (unf_env :: TcEnv) is used for type-checking interface pragmas
122 -- which is done lazily [ie failure just drops the pragma
123 -- without having any global-failure effect].
125 -- unf_env is also used to get the pragama info
126 -- for imported dfuns and default methods
128 tcModule pcs hst get_fixity this_mod decls unf_env
129 = -- Type-check the type and class decls
130 tcTyAndClassDecls unf_env decls `thenTc` \ env ->
133 classes = tcEnvClasses env
134 tycons = tcEnvTyCons env -- INCLUDES tycons derived from classes
135 local_tycons = [ tc | tc <- tycons,
137 not (isClassTyCon tc)
139 -- For local_tycons, filter out the ones derived from classes
140 -- Otherwise the latter show up in interface files
143 -- Typecheck the instance decls, includes deriving
144 tcInstDecls1 pcs hst unf_env get_fixity this_mod
145 local_tycons decls `thenTc` \ (pcs_with_insts, inst_env, inst_info, deriv_binds) ->
146 tcSetInstEnv inst_env $
148 -- Default declarations
149 tcDefaults decls `thenTc` \ defaulting_tys ->
150 tcSetDefaultTys defaulting_tys $
152 -- Interface type signatures
153 -- We tie a knot so that the Ids read out of interfaces are in scope
154 -- when we read their pragmas.
155 -- What we rely on is that pragmas are typechecked lazily; if
156 -- any type errors are found (ie there's an inconsistency)
157 -- we silently discard the pragma
158 -- We must do this before mkImplicitDataBinds (which comes next), since
159 -- the latter looks up unpackCStringId, for example, which is usually
161 tcInterfaceSigs unf_env decls `thenTc` \ sig_ids ->
162 tcExtendGlobalValEnv sig_ids $
164 -- Create any necessary record selector Ids and their bindings
165 -- "Necessary" includes data and newtype declarations
166 -- We don't create bindings for dictionary constructors;
167 -- they are always fully applied, and the bindings are just there
168 -- to support partial applications
169 mkImplicitDataBinds tycons `thenTc` \ (data_ids, imp_data_binds) ->
170 mkImplicitClassBinds classes `thenNF_Tc` \ (cls_ids, imp_cls_binds) ->
172 -- Extend the global value environment with
174 -- (b) record selectors
175 -- (c) class op selectors
176 -- (d) default-method ids... where? I can't see where these are
177 -- put into the envt, and I'm worried that the zonking phase
178 -- will find they aren't there and complain.
179 tcExtendGlobalValEnv data_ids $
180 tcExtendGlobalValEnv cls_ids $
182 -- Foreign import declarations next
183 tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
184 tcExtendGlobalValEnv fo_ids $
186 -- Value declarations next.
187 -- We also typecheck any extra binds that came out of the "deriving" process
188 tcTopBinds (get_binds decls `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
191 -- Foreign export declarations next
192 tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
194 -- Second pass over class and instance declarations,
195 -- to compile the bindings themselves.
196 tcInstDecls2 inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
197 tcClassDecls2 decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
198 tcRules decls `thenNF_Tc` \ (lie_rules, rules) ->
200 -- Deal with constant or ambiguous InstIds. How could
201 -- there be ambiguous ones? They can only arise if a
202 -- top-level decl falls under the monomorphism
203 -- restriction, and no subsequent decl instantiates its
204 -- type. (Usually, ambiguous type variables are resolved
205 -- during the generalisation step.)
207 lie_alldecls = lie_valdecls `plusLIE`
208 lie_instdecls `plusLIE`
209 lie_clasdecls `plusLIE`
210 lie_fodecls `plusLIE`
213 tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
215 -- Check that Main defines main
216 checkMain this_mod `thenTc_`
218 -- Backsubstitution. This must be done last.
219 -- Even tcSimplifyTop may do some unification.
221 all_binds = imp_data_binds `AndMonoBinds`
222 imp_cls_binds `AndMonoBinds`
223 val_binds `AndMonoBinds`
224 inst_binds `AndMonoBinds`
225 cls_dm_binds `AndMonoBinds`
226 const_inst_binds `AndMonoBinds`
229 zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
231 -- zonkTopBinds puts all the top-level Ids into the tcGEnv
232 zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
233 zonkRules rules `thenNF_Tc` \ rules' ->
236 let groups :: FiniteMap Module TypeEnv
237 groups = groupTyThings (nameEnvElts (getTcGEnv final_env))
239 local_type_env :: TypeEnv
240 local_type_env = lookupWithDefaultFM groups emptyNameEnv this_mod
242 new_pst :: PackageSymbolTable
243 new_pst = extendTypeEnv (pcs_PST pcs) (delFromFM groups this_mod)
245 final_pcs :: PersistentCompilerState
246 final_pcs = pcs_with_insts {pcs_PST = new_pst}
248 returnTc (final_env, -- WAS: really_final_env,
249 TcResults { tc_pcs = final_pcs,
250 tc_env = local_type_env,
251 tc_binds = all_binds',
252 tc_insts = map iDFunId inst_info,
253 tc_fords = foi_decls ++ foe_decls',
257 get_binds decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
262 checkMain :: Module -> TcM ()
264 | moduleName this_mod == mAIN_Name
265 = tcLookupGlobal_maybe mainName `thenNF_Tc` \ maybe_main ->
267 Just (AnId _) -> returnTc ()
268 other -> addErrTc noMainErr
270 | otherwise = returnTc ()
273 = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
274 ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
278 %************************************************************************
280 \subsection{Dumping output}
282 %************************************************************************
285 printTcDump dflags Nothing = return ()
286 printTcDump dflags (Just (_,results))
287 = do dumpIfSet_dyn dflags Opt_D_dump_types
288 "Type signatures" (dump_sigs results)
289 dumpIfSet_dyn dflags Opt_D_dump_tc
290 "Typechecked" (dump_tc results)
293 = vcat [ppr (tc_binds results),
294 pp_rules (tc_rules results),
295 ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)]
298 dump_sigs results -- Print type signatures
299 = -- Convert to HsType so that we get source-language style printing
300 -- And sort by RdrName
301 vcat $ map ppr_sig $ sortLt lt_sig $
302 [(toRdrName id, toHsType (idType id))
303 | AnId id <- nameEnvElts (tc_env results),
307 lt_sig (n1,_) (n2,_) = n1 < n2
308 ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
310 want_sig id | opt_PprStyle_Debug = True
311 | otherwise = isLocallyDefined n &&
313 not (isSysOcc (nameOccName n))
317 ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
318 vcat (map ppr_gen_tycon (filter isLocallyDefined tcs)),
322 -- x&y are now Id's, not CoreExpr's
324 | Just ep <- tyConGenInfo tycon
325 = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
327 | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
330 = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau),
331 ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
332 ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
335 (_,from_tau) = splitForAllTys (idType from)
338 pp_rules rs = vcat [ptext SLIT("{-# RULES"),
339 nest 4 (vcat (map ppr rs)),