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, 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)
74 -- All these fields have info *just for this module*
75 tc_env :: TypeEnv, -- The top level TypeEnv
76 tc_insts :: [DFunId], -- Instances
77 tc_binds :: TypecheckedMonoBinds, -- Bindings
78 tc_fords :: [TypecheckedForeignDecl], -- Foreign import & exports.
79 tc_rules :: [TypecheckedRuleDecl] -- Transformation rules
86 -> PersistentCompilerState
87 -> HomeSymbolTable -> HomeIfaceTable
89 -> IO (Maybe TcResults)
91 typecheckModule dflags this_mod pcs hst hit decls
92 = do env <- initTcEnv global_symbol_table
94 (maybe_result, (errs,warns)) <- initTc dflags env tc_module
96 let { maybe_tc_result :: Maybe TcResults ;
97 maybe_tc_result = case maybe_result of
99 Just (_,r) -> Just r }
101 printErrorsAndWarnings (errs,warns)
102 printTcDump dflags maybe_tc_result
104 if isEmptyBag errs then
107 return maybe_tc_result
109 global_symbol_table = pcs_PST pcs `plusModuleEnv` hst
111 tc_module :: TcM (TcEnv, TcResults)
112 tc_module = fixTc (\ ~(unf_env ,_) -> tcModule pcs hst get_fixity this_mod decls unf_env)
116 get_fixity :: Name -> Maybe Fixity
117 get_fixity nm = lookupTable hit pit nm `thenMaybe` \ iface ->
118 lookupNameEnv (mi_fixities iface) nm
121 The internal monster:
123 tcModule :: PersistentCompilerState
125 -> (Name -> Maybe Fixity)
128 -> TcEnv -- The knot-tied environment
129 -> TcM (TcEnv, TcResults)
131 -- (unf_env :: TcEnv) is used for type-checking interface pragmas
132 -- which is done lazily [ie failure just drops the pragma
133 -- without having any global-failure effect].
135 -- unf_env is also used to get the pragama info
136 -- for imported dfuns and default methods
138 tcModule pcs hst get_fixity this_mod decls unf_env
139 = -- Type-check the type and class decls
140 tcTyAndClassDecls unf_env decls `thenTc` \ env ->
143 classes = tcEnvClasses env
144 tycons = tcEnvTyCons env -- INCLUDES tycons derived from classes
145 local_tycons = [ tc | tc <- tycons,
147 not (isClassTyCon tc)
149 -- For local_tycons, filter out the ones derived from classes
150 -- Otherwise the latter show up in interface files
153 -- Typecheck the instance decls, includes deriving
154 tcInstDecls1 (pcs_insts pcs) (pcs_PRS pcs)
155 hst unf_env get_fixity this_mod
156 local_tycons decls `thenTc` \ (new_pcs_insts, inst_env, local_inst_info, deriv_binds) ->
157 tcSetInstEnv inst_env $
159 -- Default declarations
160 tcDefaults decls `thenTc` \ defaulting_tys ->
161 tcSetDefaultTys defaulting_tys $
163 -- Interface type signatures
164 -- We tie a knot so that the Ids read out of interfaces are in scope
165 -- when we read their pragmas.
166 -- What we rely on is that pragmas are typechecked lazily; if
167 -- any type errors are found (ie there's an inconsistency)
168 -- we silently discard the pragma
169 -- We must do this before mkImplicitDataBinds (which comes next), since
170 -- the latter looks up unpackCStringId, for example, which is usually
172 tcInterfaceSigs unf_env decls `thenTc` \ sig_ids ->
173 tcExtendGlobalValEnv sig_ids $
175 -- Create any necessary record selector Ids and their bindings
176 -- "Necessary" includes data and newtype declarations
177 -- We don't create bindings for dictionary constructors;
178 -- they are always fully applied, and the bindings are just there
179 -- to support partial applications
180 mkImplicitDataBinds tycons `thenTc` \ (data_ids, imp_data_binds) ->
181 mkImplicitClassBinds classes `thenNF_Tc` \ (cls_ids, imp_cls_binds) ->
183 -- Extend the global value environment with
185 -- (b) record selectors
186 -- (c) class op selectors
187 -- (d) default-method ids... where? I can't see where these are
188 -- put into the envt, and I'm worried that the zonking phase
189 -- will find they aren't there and complain.
190 tcExtendGlobalValEnv data_ids $
191 tcExtendGlobalValEnv cls_ids $
193 -- Foreign import declarations next
194 tcForeignImports decls `thenTc` \ (fo_ids, foi_decls) ->
195 tcExtendGlobalValEnv fo_ids $
197 -- Value declarations next.
198 -- We also typecheck any extra binds that came out of the "deriving" process
199 tcTopBinds (get_binds decls `ThenBinds` deriv_binds) `thenTc` \ ((val_binds, env), lie_valdecls) ->
202 -- Foreign export declarations next
203 tcForeignExports decls `thenTc` \ (lie_fodecls, foe_binds, foe_decls) ->
205 -- Second pass over class and instance declarations,
206 -- to compile the bindings themselves.
207 tcInstDecls2 local_inst_info `thenNF_Tc` \ (lie_instdecls, inst_binds) ->
208 tcClassDecls2 decls `thenNF_Tc` \ (lie_clasdecls, cls_dm_binds) ->
209 tcRules (pcs_rules pcs) decls `thenNF_Tc` \ (new_pcs_rules, lie_rules, local_rules) ->
211 -- Deal with constant or ambiguous InstIds. How could
212 -- there be ambiguous ones? They can only arise if a
213 -- top-level decl falls under the monomorphism
214 -- restriction, and no subsequent decl instantiates its
215 -- type. (Usually, ambiguous type variables are resolved
216 -- during the generalisation step.)
218 lie_alldecls = lie_valdecls `plusLIE`
219 lie_instdecls `plusLIE`
220 lie_clasdecls `plusLIE`
221 lie_fodecls `plusLIE`
224 tcSimplifyTop lie_alldecls `thenTc` \ const_inst_binds ->
226 -- Check that Main defines main
227 checkMain this_mod `thenTc_`
229 -- Backsubstitution. This must be done last.
230 -- Even tcSimplifyTop may do some unification.
232 all_binds = imp_data_binds `AndMonoBinds`
233 imp_cls_binds `AndMonoBinds`
234 val_binds `AndMonoBinds`
235 inst_binds `AndMonoBinds`
236 cls_dm_binds `AndMonoBinds`
237 const_inst_binds `AndMonoBinds`
240 zonkTopBinds all_binds `thenNF_Tc` \ (all_binds', final_env) ->
242 -- zonkTopBinds puts all the top-level Ids into the tcGEnv
243 zonkForeignExports foe_decls `thenNF_Tc` \ foe_decls' ->
244 zonkRules local_rules `thenNF_Tc` \ local_rules' ->
247 let groups :: FiniteMap Module TypeEnv
248 groups = groupTyThings (nameEnvElts (getTcGEnv final_env))
250 local_type_env :: TypeEnv
251 local_type_env = lookupWithDefaultFM groups emptyNameEnv this_mod
253 new_pst :: PackageSymbolTable
254 new_pst = extendTypeEnv (pcs_PST pcs) (delFromFM groups this_mod)
256 final_pcs :: PersistentCompilerState
257 final_pcs = pcs { pcs_PST = new_pst,
258 pcs_insts = new_pcs_insts,
259 pcs_rules = new_pcs_rules
263 TcResults { tc_pcs = final_pcs,
264 tc_env = local_type_env,
265 tc_binds = all_binds',
266 tc_insts = map iDFunId local_inst_info,
267 tc_fords = foi_decls ++ foe_decls',
271 get_binds decls = foldr ThenBinds EmptyBinds [binds | ValD binds <- decls]
276 checkMain :: Module -> TcM ()
278 | moduleName this_mod == mAIN_Name
279 = tcLookupGlobal_maybe mainName `thenNF_Tc` \ maybe_main ->
281 Just (AnId _) -> returnTc ()
282 other -> addErrTc noMainErr
284 | otherwise = returnTc ()
287 = hsep [ptext SLIT("Module"), quotes (ppr mAIN_Name),
288 ptext SLIT("must include a definition for"), quotes (ptext SLIT("main"))]
292 %************************************************************************
294 \subsection{Dumping output}
296 %************************************************************************
299 printTcDump dflags Nothing = return ()
300 printTcDump dflags (Just results)
301 = do dumpIfSet_dyn dflags Opt_D_dump_types
302 "Type signatures" (dump_sigs results)
303 dumpIfSet_dyn dflags Opt_D_dump_tc
304 "Typechecked" (dump_tc results)
307 = vcat [ppr (tc_binds results),
308 pp_rules (tc_rules results),
309 ppr_gen_tycons [tc | ATyCon tc <- nameEnvElts (tc_env results)]
312 dump_sigs results -- Print type signatures
313 = -- Convert to HsType so that we get source-language style printing
314 -- And sort by RdrName
315 vcat $ map ppr_sig $ sortLt lt_sig $
316 [(toRdrName id, toHsType (idType id))
317 | AnId id <- nameEnvElts (tc_env results),
321 lt_sig (n1,_) (n2,_) = n1 < n2
322 ppr_sig (n,t) = ppr n <+> dcolon <+> ppr t
324 want_sig id | opt_PprStyle_Debug = True
325 | otherwise = isLocallyDefined n &&
327 not (isSysOcc (nameOccName n))
331 ppr_gen_tycons tcs = vcat [ptext SLIT("{-# Generic type constructor details"),
332 vcat (map ppr_gen_tycon (filter isLocallyDefined tcs)),
336 -- x&y are now Id's, not CoreExpr's
338 | Just ep <- tyConGenInfo tycon
339 = (ppr tycon <> colon) $$ nest 4 (ppr_ep ep)
341 | otherwise = ppr tycon <> colon <+> ptext SLIT("Not derivable")
344 = vcat [ ptext SLIT("Rep type:") <+> ppr (funResultTy from_tau),
345 ptext SLIT("From:") <+> ppr (unfoldingTemplate (idUnfolding from)),
346 ptext SLIT("To:") <+> ppr (unfoldingTemplate (idUnfolding to))
349 (_,from_tau) = splitForAllTys (idType from)
352 pp_rules rs = vcat [ptext SLIT("{-# RULES"),
353 nest 4 (vcat (map ppr rs)),