2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcIfaceSig]{Type checking of type signatures in interface files}
8 tcImportDecl, typecheckIface,
9 tcIfaceKind, loadImportedInsts, loadImportedRules,
12 #include "HsVersions.h"
15 import LoadIface ( loadHomeInterface, predInstGates )
16 import IfaceEnv ( lookupIfaceTop, newGlobalBinder, lookupOrig,
17 extendIfaceIdEnv, extendIfaceTyVarEnv, newIPName,
18 tcIfaceTyVar, tcIfaceTyCon, tcIfaceClass, tcIfaceExtId,
19 tcIfaceDataCon, tcIfaceLclId,
20 newIfaceName, newIfaceNames )
21 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass )
23 import Type ( Kind, openTypeKind, liftedTypeKind,
24 unliftedTypeKind, mkArrowKind, splitTyConApp,
25 mkTyVarTys, mkGenTyConApp, mkTyVarTys, ThetaType )
26 import TypeRep ( Type(..), PredType(..) )
27 import TyCon ( TyCon, tyConName )
28 import HscTypes ( ExternalPackageState(..), PackageInstEnv, PackageRuleBase,
29 HscEnv, TyThing(..), implicitTyThings, typeEnvIds,
30 ModIface(..), ModDetails(..), InstPool, ModGuts,
31 TypeEnv, mkTypeEnv, extendTypeEnvList, lookupTypeEnv,
32 DeclPool, RulePool, Pool(..), Gated, addRuleToPool )
33 import InstEnv ( extendInstEnv )
35 import PprType ( pprClassPred )
36 import PprCore ( pprIdRules )
37 import Rules ( extendRuleBaseList )
38 import CoreUtils ( exprType )
40 import CoreLint ( lintUnfolding )
41 import WorkWrap ( mkWrapper )
42 import InstEnv ( DFunId )
43 import Id ( Id, mkVanillaGlobal, mkLocalId )
44 import MkId ( mkFCallId )
45 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
46 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
47 setArityInfo, setInlinePragInfo, setCafInfo,
48 vanillaIdInfo, newStrictnessInfo )
49 import Class ( Class )
50 import TyCon ( DataConDetails(..), tyConDataCons, tyConTyVars, isTupleTyCon, mkForeignTyCon )
51 import DataCon ( dataConWorkId, dataConExistentialTyVars, dataConArgTys )
52 import TysWiredIn ( tupleCon )
53 import Var ( TyVar, mkTyVar, tyVarKind )
54 import Name ( Name, NamedThing(..), nameModuleName, nameModule, nameOccName,
55 isWiredInName, wiredInNameTyThing_maybe, nameParent )
57 import OccName ( OccName )
58 import Module ( Module, ModuleName, moduleName )
59 import UniqSupply ( initUs_ )
61 import SrcLoc ( noSrcLoc )
62 import Util ( zipWithEqual, dropList, equalLength, zipLazy )
63 import Maybes ( expectJust )
64 import CmdLineOpts ( DynFlag(..) )
73 An IfaceDecl is populated with RdrNames, and these are not renamed to
74 Names before typechecking, because there should be no scope errors etc.
76 -- For (b) consider: f = $(...h....)
77 -- where h is imported, and calls f via an hi-boot file.
78 -- This is bad! But it is not seen as a staging error, because h
79 -- is indeed imported. We don't want the type-checker to black-hole
80 -- when simplifying and compiling the splice!
82 -- Simple solution: discard any unfolding that mentions a variable
83 -- bound in this module (and hence not yet processed).
84 -- The discarding happens when forkM finds a type error.
86 %************************************************************************
88 %* tcImportDecl is the key function for "faulting in" *
91 %************************************************************************
93 The main idea is this. We are chugging along type-checking source code, and
94 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
95 it in the EPS type envt. So it
97 2 gets the decl for GHC.Base.map
98 3 typechecks it via tcIfaceDecl
99 4 and adds it to the type env in the EPS
101 Note that DURING STEP 4, we may find that map's type mentions a type
102 constructor that also
104 Notice that for imported things we read the current version from the EPS
105 mutable variable. This is important in situations like
107 where the code that e1 expands to might import some defns that
108 also turn out to be needed by the code that e2 expands to.
111 tcImportDecl :: Name -> IfG TyThing
112 -- Get the TyThing for this Name from an interface file
115 -- Make sure the interface is loaded
116 ; let { nd_doc = ptext SLIT("Need decl for") <+> ppr name }
117 ; traceIf (nd_doc <+> char '{') -- Brace matches the later message
118 ; loadHomeInterface nd_doc name
120 -- Get the real name of the thing, with a correct nameParent field.
121 -- Before the interface is loaded, we may have a non-committal 'Nothing'
122 -- in the namePareent field (made up by IfaceEnv.lookupOrig), but
123 -- loading the interface updates the name cache.
124 -- We need the right nameParent field in getThing
125 ; real_name <- lookupOrig (nameModuleName name) (nameOccName name)
127 -- Get the decl out of the EPS
128 ; main_thing <- ASSERT( real_name == name ) -- Unique should not change!
131 -- Record the import in the type env,
132 -- slurp any rules it allows in
133 ; recordImportOf main_thing
135 ; let { extra | getName main_thing == real_name = empty
136 | otherwise = brackets (ptext SLIT("when seeking") <+> ppr real_name) }
137 ; traceIf (ptext SLIT(" ...imported decl for") <+> ppr main_thing <+> extra <+> char '}')
140 -- Look up the wanted Name in the type envt; it might be
141 -- one of the subordinate members of the input thing
142 ; if real_name == getName main_thing
143 then return main_thing
146 ; return (expectJust "tcImportDecl" $
147 lookupTypeEnv (eps_PTE eps) real_name) }}
149 recordImportOf :: TyThing -> IfG ()
150 -- Update the EPS to record the import of the Thing
151 -- (a) augment the type environment; this is done even for wired-in
152 -- things, so that we don't go through this rigmarole a second time
153 -- (b) slurp in any rules to maintain the invariant that any rule
154 -- whose gates are all in the type envt, is in eps_rule_base
157 = do { new_things <- updateEps (\ eps ->
158 let { new_things = thing : implicitTyThings thing
159 ; new_type_env = extendTypeEnvList (eps_PTE eps) new_things
160 -- NB: opportunity for a very subtle loop here!
161 -- If working out what the implicitTyThings are involves poking
162 -- any of the fork'd thunks in 'thing', then here's what happens
163 -- * recordImportOf succeed, extending type-env with a thunk
164 -- * the next guy to pull on type-env forces the thunk
165 -- * which pokes the suspended forks
166 -- * which, to execute, need to consult type-env (to check
167 -- entirely unrelated types, perhaps)
169 in (eps { eps_PTE = new_type_env }, new_things)
171 ; traceIf (text "tcImport: extend type env" <+> ppr new_things)
174 getThing :: Name -> IfG TyThing
175 -- Find and typecheck the thing; the Name might be a "subordinate name"
176 -- of the "main thing" (e.g. the constructor of a data type declaration)
177 -- The Thing we return is the parent "main thing"
180 | Just thing <- wiredInNameTyThing_maybe name
183 | otherwise = do -- The normal case, not wired in
184 { -- Get the decl from the pool
185 decl <- updateEps (\ eps ->
187 (decls', decl) = selectDecl (eps_decls eps) name
189 (eps { eps_decls = decls' }, decl))
192 -- Side-effects EPS by faulting in any needed decls
193 -- (via nested calls to tcImportDecl)
194 ; initIfaceLcl (nameModuleName name) (tcIfaceDecl decl) }
197 selectDecl :: DeclPool -> Name -> (DeclPool, IfaceDecl)
198 -- Use nameParent to get the parent name of the thing
199 selectDecl (Pool decls_map n_in n_out) name
200 = (Pool decls' n_in (n_out+1), decl)
202 main_name = nameParent name
203 decl = case lookupNameEnv decls_map main_name of
204 Nothing -> pprPanic "selectDecl" (ppr main_name <+> ppr name) ;
207 decls' = delFromNameEnv decls_map main_name
210 %************************************************************************
212 Type-checking a complete interface
214 %************************************************************************
216 Suppose we discover we don't need to recompile. Then we must type
217 check the old interface file. This is a bit different to the
218 incremental type checking we do as we suck in interface files. Instead
219 we do things similarly as when we are typechecking source decls: we
220 bring into scope the type envt for the interface all at once, using a
221 knot. Remember, the decls aren't necessarily in dependency order --
222 and even if they were, the type decls might be mutually recursive.
225 typecheckIface :: HscEnv
226 -> ModIface -- Get the decls from here
228 typecheckIface hsc_env iface@(ModIface { mi_module = mod, mi_decls = ver_decls,
229 mi_rules = rules, mi_insts = dfuns })
230 = initIfaceTc hsc_env iface $ \ tc_env_var -> do
231 { -- Typecheck the decls
232 names <- mappM (lookupOrig (moduleName mod) . ifName) decls
233 ; ty_things <- fixM (\ rec_ty_things -> do
234 { writeMutVar tc_env_var (mkNameEnv (names `zipLazy` rec_ty_things))
235 -- This only makes available the "main" things,
236 -- but that's enough for the strictly-checked part
237 ; mapM tcIfaceDecl decls })
239 -- Now augment the type envt with all the implicit things
240 -- These will be needed when type-checking the unfoldings for
241 -- the IfaceIds, but this is done lazily, so writing the thing
243 ; let { add_implicits main_thing = main_thing : implicitTyThings main_thing
244 ; type_env = mkTypeEnv (concatMap add_implicits ty_things) }
245 ; writeMutVar tc_env_var type_env
247 -- Now do those rules and instances
248 ; dfuns <- mapM tcIfaceInst (mi_insts iface)
249 ; rules <- mapM tcIfaceRule (mi_rules iface)
252 ; return (ModDetails { md_types = type_env, md_insts = dfuns, md_rules = rules })
255 decls = map snd ver_decls
259 %************************************************************************
261 Type and class declarations
263 %************************************************************************
265 When typechecking a data type decl, we *lazily* (via forkM) typecheck
266 the constructor argument types. This is in the hope that we may never
267 poke on those argument types, and hence may never need to load the
268 interface files for types mentioned in the arg types.
271 data Foo.S = MkS Baz.T
272 Mabye we can get away without even loading the interface for Baz!
274 This is not just a performance thing. Suppose we have
275 data Foo.S = MkS Baz.T
276 data Baz.T = MkT Foo.S
277 (in different interface files, of course).
278 Now, first we load and typecheck Foo.S, and add it to the type envt.
279 If we do explore MkS's argument, we'll load and typecheck Baz.T.
280 If we explore MkT's argument we'll find Foo.S already in the envt.
282 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
283 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
284 which isn't done yet.
286 All very cunning. However, there is a rather subtle gotcha which bit
287 me when developing this stuff. When we typecheck the decl for S, we
288 extend the type envt with S, MkS, and all its implicit Ids. Suppose
289 (a bug, but it happened) that the list of implicit Ids depended in
290 turn on the constructor arg types. Then the following sequence of
292 * we build a thunk <t> for the constructor arg tys
293 * we build a thunk for the extended type environment (depends on <t>)
294 * we write the extended type envt into the global EPS mutvar
296 Now we look something up in the type envt
298 * which reads the global type envt out of the global EPS mutvar
299 * but that depends in turn on <t>
301 It's subtle, because, it'd work fine if we typechecked the constructor args
302 eagerly -- they don't need the extended type envt. They just get the extended
303 type envt by accident, because they look at it later.
305 What this means is that the implicitTyThings MUST NOT DEPEND on any of
310 tcIfaceDecl :: IfaceDecl -> IfL TyThing
312 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
313 = do { name <- lookupIfaceTop occ_name
314 ; ty <- tcIfaceType iface_type
315 ; info <- tcIdInfo name ty info
316 ; return (AnId (mkVanillaGlobal name ty info)) }
318 tcIfaceDecl (IfaceData {ifND = new_or_data, ifName = occ_name,
319 ifTyVars = tv_bndrs, ifCtxt = rdr_ctxt,
321 ifVrcs = arg_vrcs, ifRec = is_rec,
322 ifGeneric = want_generic })
323 = do { tc_name <- lookupIfaceTop occ_name
324 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
326 { traceIf (text "tcIfaceDecl" <+> ppr rdr_ctxt)
328 ; ctxt <- forkM (ptext SLIT("Ctxt of data decl") <+> ppr tc_name) $
330 -- The reason for laziness here is to postpone
331 -- looking at the context, because the class may not
332 -- be in the type envt yet. E.g.
333 -- class Real a where { toRat :: a -> Ratio Integer }
334 -- data (Real a) => Ratio a = ...
335 -- We suck in the decl for Real, and type check it, which sucks
336 -- in the data type Ratio; but we must postpone typechecking the
339 ; tycon <- fixM ( \ tycon -> do
340 { cons <- tcIfaceDataCons tycon tyvars ctxt rdr_cons
341 ; tycon <- buildAlgTyCon new_or_data tc_name tyvars ctxt cons
342 arg_vrcs is_rec want_generic
345 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
346 ; return (ATyCon tycon)
349 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
350 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
351 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
352 { tc_name <- lookupIfaceTop occ_name
353 ; rhs_ty <- tcIfaceType rdr_rhs_ty
354 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
357 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
358 ifFDs = rdr_fds, ifSigs = rdr_sigs,
359 ifVrcs = tc_vrcs, ifRec = tc_isrec })
360 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
361 { cls_name <- lookupIfaceTop occ_name
362 ; ctxt <- tcIfaceCtxt rdr_ctxt
363 ; sigs <- mappM tc_sig rdr_sigs
364 ; fds <- mappM tc_fd rdr_fds
365 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
366 ; return (AClass cls) }
368 tc_sig (IfaceClassOp occ dm rdr_ty)
369 = do { op_name <- lookupIfaceTop occ
370 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
371 -- Must be done lazily for just the same reason as the
372 -- context of a data decl: the type sig might mention the
373 -- class being defined
374 ; return (op_name, dm, op_ty) }
376 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
378 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
379 ; tvs2' <- mappM tcIfaceTyVar tvs2
380 ; return (tvs1', tvs2') }
382 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
383 = do { name <- lookupIfaceTop rdr_name
384 ; return (ATyCon (mkForeignTyCon name ext_name
385 liftedTypeKind 0 [])) }
387 tcIfaceDataCons tycon tyvars ctxt Unknown
390 tcIfaceDataCons tycon tyvars ctxt (DataCons cs)
391 = mappM tc_con_decl cs `thenM` \ data_cons ->
392 returnM (DataCons data_cons)
394 tc_con_decl (IfaceConDecl occ ex_tvs ex_ctxt args stricts field_lbls)
395 = bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
396 { name <- lookupIfaceTop occ
397 ; ex_theta <- tcIfaceCtxt ex_ctxt -- Laziness seems not worth the bother here
399 -- Read the argument types, but lazily to avoid faulting in
400 -- the component types unless they are really needed
401 ; arg_tys <- forkM (mk_doc name args) (mappM tcIfaceType args) ;
403 ; lbl_names <- mappM lookupIfaceTop field_lbls
405 ; buildDataCon name stricts lbl_names
406 tyvars ctxt ex_tyvars ex_theta
409 mk_doc con_name args = ptext SLIT("Constructor") <+> sep [ppr con_name, ppr args]
413 %************************************************************************
417 %************************************************************************
419 The gating story for instance declarations
420 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
421 When we are looking for a dict (C t1..tn), we slurp in instance decls for
423 mention at least one of the type constructors
424 at the roots of t1..tn
426 Why "at least one" rather than "all"? Because functional dependencies
427 complicate the picture. Consider
428 class C a b | a->b where ...
429 instance C Foo Baz where ...
430 Here, the gates are really only C and Foo, *not* Baz.
431 That is, if C and Foo are visible, even if Baz isn't, we must
432 slurp the decl, even if Baz is thus far completely unknown to the
435 Why "roots of the types"? Reason is overlap. For example, suppose there
436 are interfaces in the pool for
440 Then, if we are trying to resolve (C Int x), we need (a)
441 if we are trying to resolve (C x [y]), we need *both* (b) and (c),
442 even though T is not involved yet, so that we spot the overlap.
445 loadImportedInsts :: Class -> [Type] -> TcM PackageInstEnv
446 loadImportedInsts cls tys
447 = do { -- Get interfaces for wired-in things, such as Integer
448 -- Any non-wired-in tycons will already be loaded, else
449 -- we couldn't have them in the Type
450 ; this_mod <- getModule
451 ; let { (cls_gate, tc_gates) = predInstGates cls tys
452 ; imp_wi n = isWiredInName n && this_mod /= nameModule n
453 ; wired_tcs = filter imp_wi tc_gates }
454 -- Wired-in tycons not from this module. The "this-module"
455 -- test bites only when compiling Base etc, because loadHomeInterface
456 -- barfs if it's asked to load a non-existent interface
457 ; if null wired_tcs then returnM ()
458 else initIfaceTcRn (mapM_ (loadHomeInterface wired_doc) wired_tcs)
460 ; eps_var <- getEpsVar
461 ; eps <- readMutVar eps_var
463 -- Suck in the instances
464 ; let { (inst_pool', iface_insts)
465 = selectInsts (eps_insts eps) cls_gate tc_gates }
467 -- Empty => finish up rapidly, without writing to eps
468 ; if null iface_insts then
469 return (eps_inst_env eps)
471 { writeMutVar eps_var (eps {eps_insts = inst_pool'})
473 ; traceIf (sep [ptext SLIT("Importing instances for") <+> pprClassPred cls tys,
474 nest 2 (vcat (map ppr iface_insts))])
476 -- Typecheck the new instances
477 ; dfuns <- initIfaceTcRn (mappM tc_inst iface_insts)
479 -- And put them in the package instance environment
480 ; updateEps ( \ eps ->
482 inst_env' = foldl extendInstEnv (eps_inst_env eps) dfuns
484 (eps { eps_inst_env = inst_env' }, inst_env')
487 wired_doc = ptext SLIT("Need home inteface for wired-in thing")
489 tc_inst (mod, inst) = initIfaceLcl mod (tcIfaceInst inst)
491 tcIfaceInst :: IfaceInst -> IfL DFunId
492 tcIfaceInst (IfaceInst { ifDFun = dfun_occ })
493 = tcIfaceExtId (LocalTop dfun_occ)
495 selectInsts :: InstPool -> Name -> [Name] -> (InstPool, [(ModuleName, IfaceInst)])
496 selectInsts pool@(Pool insts n_in n_out) cls tycons
497 = (Pool insts' n_in (n_out + length iface_insts), iface_insts)
499 (insts', iface_insts)
500 = case lookupNameEnv insts cls of {
501 Nothing -> (insts, []) ;
504 case foldl choose ([],[]) gated_insts of {
505 (_, []) -> (insts, []) ; -- None picked
506 (gated_insts', iface_insts') ->
508 (extendNameEnv insts cls gated_insts', iface_insts') }}
510 -- Reverses the gated decls, but that doesn't matter
511 choose (gis, decls) (gates, decl)
512 | any (`elem` tycons) gates = (gis, decl:decls)
513 | otherwise = ((gates,decl) : gis, decls)
516 %************************************************************************
520 %************************************************************************
522 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
523 are in the type environment. However, remember that typechecking a Rule may
524 (as a side effect) augment the type envt, and so we may need to iterate the process.
527 loadImportedRules :: HscEnv -> ModGuts -> IO PackageRuleBase
528 loadImportedRules hsc_env guts
529 = initIfaceRules hsc_env guts $ do
531 if_rules <- updateEps (\ eps ->
532 let { (new_pool, if_rules) = selectRules (eps_rules eps) (eps_PTE eps) }
533 in (eps { eps_rules = new_pool }, if_rules) )
535 ; traceIf (ptext SLIT("Importing rules:") <+> vcat (map ppr if_rules))
537 ; let tc_rule (mod, rule) = initIfaceLcl mod (tcIfaceRule rule)
538 ; core_rules <- mapM tc_rule if_rules
541 ; traceIf (ptext SLIT("Imported rules:") <+> pprIdRules core_rules)
543 -- Update the rule base and return it
544 ; updateEps (\ eps ->
545 let { new_rule_base = extendRuleBaseList (eps_rule_base eps) core_rules }
546 in (eps { eps_rule_base = new_rule_base }, new_rule_base)
549 -- Strictly speaking, at this point we should go round again, since
550 -- typechecking one set of rules may bring in new things which enable
551 -- some more rules to come in. But we call loadImportedRules several
552 -- times anyway, so I'm going to be lazy and ignore this.
556 selectRules :: RulePool -> TypeEnv -> (RulePool, [(ModuleName, IfaceRule)])
557 -- Not terribly efficient. Look at each rule in the pool to see if
558 -- all its gates are in the type env. If so, take it out of the pool.
559 -- If not, trim its gates for next time.
560 selectRules (Pool rules n_in n_out) type_env
561 = (Pool rules' n_in (n_out + length if_rules), if_rules)
563 (rules', if_rules) = foldl do_one ([], []) rules
565 do_one (pool, if_rules) (gates, rule)
566 | null gates' = (pool, rule:if_rules)
567 | otherwise = ((gates',rule) : pool, if_rules)
569 gates' = filter (`elemNameEnv` type_env) gates
572 tcIfaceRule :: IfaceRule -> IfL IdCoreRule
573 tcIfaceRule (IfaceRule {ifRuleName = rule_name, ifActivation = act, ifRuleBndrs = bndrs,
574 ifRuleHead = fn_rdr, ifRuleArgs = args, ifRuleRhs = rhs })
575 = bindIfaceBndrs bndrs $ \ bndrs' ->
576 do { fn <- tcIfaceExtId fn_rdr
577 ; args' <- mappM tcIfaceExpr args
578 ; rhs' <- tcIfaceExpr rhs
579 ; returnM (fn, (Rule rule_name act bndrs' args' rhs')) }
581 tcIfaceRule (IfaceBuiltinRule fn_rdr core_rule)
582 = do { fn <- tcIfaceExtId fn_rdr
583 ; returnM (fn, core_rule) }
587 %************************************************************************
591 %************************************************************************
594 tcIfaceKind :: IfaceKind -> Kind
595 tcIfaceKind IfaceOpenTypeKind = openTypeKind
596 tcIfaceKind IfaceLiftedTypeKind = liftedTypeKind
597 tcIfaceKind IfaceUnliftedTypeKind = unliftedTypeKind
598 tcIfaceKind (IfaceFunKind k1 k2) = mkArrowKind (tcIfaceKind k1) (tcIfaceKind k2)
600 -----------------------------------------
601 tcIfaceType :: IfaceType -> IfL Type
602 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
603 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
604 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
605 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkGenTyConApp tc' ts') }
606 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
607 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
609 tcIfaceTypes tys = mapM tcIfaceType tys
611 -----------------------------------------
612 tcIfacePredType :: IfacePredType -> IfL PredType
613 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
614 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
616 -----------------------------------------
617 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
618 tcIfaceCtxt sts = mappM tcIfacePredType sts
622 %************************************************************************
626 %************************************************************************
629 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
630 tcIfaceExpr (IfaceType ty)
631 = tcIfaceType ty `thenM` \ ty' ->
634 tcIfaceExpr (IfaceLcl name)
635 = tcIfaceLclId name `thenM` \ id ->
638 tcIfaceExpr (IfaceExt gbl)
639 = tcIfaceExtId gbl `thenM` \ id ->
642 tcIfaceExpr (IfaceLit lit)
645 tcIfaceExpr (IfaceFCall cc ty)
646 = tcIfaceType ty `thenM` \ ty' ->
647 newUnique `thenM` \ u ->
648 returnM (Var (mkFCallId u cc ty'))
650 tcIfaceExpr (IfaceTuple boxity args)
651 = mappM tcIfaceExpr args `thenM` \ args' ->
653 -- Put the missing type arguments back in
654 con_args = map (Type . exprType) args' ++ args'
656 returnM (mkApps (Var con_id) con_args)
659 con_id = dataConWorkId (tupleCon boxity arity)
662 tcIfaceExpr (IfaceLam bndr body)
663 = bindIfaceBndr bndr $ \ bndr' ->
664 tcIfaceExpr body `thenM` \ body' ->
665 returnM (Lam bndr' body')
667 tcIfaceExpr (IfaceApp fun arg)
668 = tcIfaceExpr fun `thenM` \ fun' ->
669 tcIfaceExpr arg `thenM` \ arg' ->
670 returnM (App fun' arg')
672 tcIfaceExpr (IfaceCase scrut case_bndr alts)
673 = tcIfaceExpr scrut `thenM` \ scrut' ->
674 newIfaceName case_bndr `thenM` \ case_bndr_name ->
676 scrut_ty = exprType scrut'
677 case_bndr' = mkLocalId case_bndr_name scrut_ty
678 tc_app = splitTyConApp scrut_ty
679 -- NB: Won't always succeed (polymoprhic case)
680 -- but won't be demanded in those cases
681 -- NB: not tcSplitTyConApp; we are looking at Core here
682 -- look through non-rec newtypes to find the tycon that
683 -- corresponds to the datacon in this case alternative
685 extendIfaceIdEnv [case_bndr'] $
686 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
687 returnM (Case scrut' case_bndr' alts')
689 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
690 = tcIfaceExpr rhs `thenM` \ rhs' ->
691 bindIfaceId bndr $ \ bndr' ->
692 tcIfaceExpr body `thenM` \ body' ->
693 returnM (Let (NonRec bndr' rhs') body')
695 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
696 = bindIfaceIds bndrs $ \ bndrs' ->
697 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
698 tcIfaceExpr body `thenM` \ body' ->
699 returnM (Let (Rec (bndrs' `zip` rhss')) body')
701 (bndrs, rhss) = unzip pairs
703 tcIfaceExpr (IfaceNote note expr)
704 = tcIfaceExpr expr `thenM` \ expr' ->
706 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
707 returnM (Note (Coerce to_ty'
708 (exprType expr')) expr')
709 IfaceInlineCall -> returnM (Note InlineCall expr')
710 IfaceInlineMe -> returnM (Note InlineMe expr')
711 IfaceSCC cc -> returnM (Note (SCC cc) expr')
712 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
714 -------------------------
715 tcIfaceAlt _ (IfaceDefault, names, rhs)
716 = ASSERT( null names )
717 tcIfaceExpr rhs `thenM` \ rhs' ->
718 returnM (DEFAULT, [], rhs')
720 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
721 = ASSERT( null names )
722 tcIfaceExpr rhs `thenM` \ rhs' ->
723 returnM (LitAlt lit, [], rhs')
725 -- A case alternative is made quite a bit more complicated
726 -- by the fact that we omit type annotations because we can
727 -- work them out. True enough, but its not that easy!
728 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
730 tycon_mod = nameModuleName (tyConName tycon)
732 tcIfaceDataCon (ExtPkg tycon_mod data_occ) `thenM` \ con ->
733 newIfaceNames arg_occs `thenM` \ arg_names ->
735 ex_tyvars = dataConExistentialTyVars con
736 main_tyvars = tyConTyVars tycon
737 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- arg_names `zip` ex_tyvars]
738 ex_tys' = mkTyVarTys ex_tyvars'
739 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
740 id_names = dropList ex_tyvars arg_names
743 | not (equalLength id_names arg_tys)
744 = pprPanic "tcIfaceAlts" (ppr (con, arg_names, rhs) $$
745 (ppr main_tyvars <+> ppr ex_tyvars) $$
749 = zipWithEqual "tcIfaceAlts" mkLocalId id_names arg_tys
751 ASSERT2( con `elem` tyConDataCons tycon && equalLength inst_tys main_tyvars,
752 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) $$ ppr arg_tys $$ ppr main_tyvars )
753 extendIfaceTyVarEnv ex_tyvars' $
754 extendIfaceIdEnv arg_ids $
755 tcIfaceExpr rhs `thenM` \ rhs' ->
756 returnM (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
758 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
759 = newIfaceNames arg_occs `thenM` \ arg_names ->
761 [con] = tyConDataCons tycon
762 arg_ids = zipWithEqual "tcIfaceAlts" mkLocalId arg_names inst_tys
764 ASSERT( isTupleTyCon tycon )
765 extendIfaceIdEnv arg_ids $
766 tcIfaceExpr rhs `thenM` \ rhs' ->
767 returnM (DataAlt con, arg_ids, rhs')
772 tcExtCoreBindings :: Module -> [IfaceBinding] -> IfL [CoreBind] -- Used for external core
773 tcExtCoreBindings mod [] = return []
774 tcExtCoreBindings mod (b:bs) = do_one mod b (tcExtCoreBindings mod bs)
776 do_one :: Module -> IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
777 do_one mod (IfaceNonRec bndr rhs) thing_inside
778 = do { rhs' <- tcIfaceExpr rhs
779 ; bndr' <- newExtCoreBndr mod bndr
780 ; extendIfaceIdEnv [bndr'] $ do
781 { core_binds <- thing_inside
782 ; return (NonRec bndr' rhs' : core_binds) }}
784 do_one mod (IfaceRec pairs) thing_inside
785 = do { bndrs' <- mappM (newExtCoreBndr mod) bndrs
786 ; extendIfaceIdEnv bndrs' $ do
787 { rhss' <- mappM tcIfaceExpr rhss
788 ; core_binds <- thing_inside
789 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
791 (bndrs,rhss) = unzip pairs
795 %************************************************************************
799 %************************************************************************
802 tcIdInfo name ty NoInfo = return vanillaIdInfo
803 tcIdInfo name ty DiscardedInfo = return vanillaIdInfo
804 tcIdInfo name ty (HasInfo iface_info)
805 = foldlM tcPrag init_info iface_info
807 -- Set the CgInfo to something sensible but uninformative before
808 -- we start; default assumption is that it has CAFs
809 init_info = vanillaIdInfo
811 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
812 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
813 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
815 -- The next two are lazy, so they don't transitively suck stuff in
816 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
817 tcPrag info (HsUnfold inline_prag expr)
818 = tcPragExpr name expr `thenM` \ maybe_expr' ->
820 -- maybe_expr' doesn't get looked at if the unfolding
821 -- is never inspected; so the typecheck doesn't even happen
822 unfold_info = case maybe_expr' of
823 Nothing -> noUnfolding
824 Just expr' -> mkTopUnfolding expr'
826 returnM (info `setUnfoldingInfoLazily` unfold_info
827 `setInlinePragInfo` inline_prag)
831 tcWorkerInfo ty info wkr_name arity
832 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId (LocalTop wkr_name))
834 -- We return without testing maybe_wkr_id, but as soon as info is
835 -- looked at we will test it. That's ok, because its outside the
836 -- knot; and there seems no big reason to further defer the
837 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
838 -- over the unfolding until it's actually used does seem worth while.)
839 ; us <- newUniqueSupply
841 ; returnM (case mb_wkr_id of
843 Just wkr_id -> add_wkr_info us wkr_id info) }
845 doc = text "Worker for" <+> ppr wkr_name
846 add_wkr_info us wkr_id info
847 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
848 `setWorkerInfo` HasWorker wkr_id arity
850 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
852 -- We are relying here on strictness info always appearing
853 -- before worker info, fingers crossed ....
854 strict_sig = case newStrictnessInfo info of
856 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr_name)
859 For unfoldings we try to do the job lazily, so that we never type check
860 an unfolding that isn't going to be looked at.
863 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
866 tcIfaceExpr expr `thenM` \ core_expr' ->
868 -- Check for type consistency in the unfolding
869 ifOptM Opt_DoCoreLinting (
870 get_in_scope_ids `thenM` \ in_scope ->
871 case lintUnfolding noSrcLoc in_scope core_expr' of
872 Nothing -> returnM ()
873 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
878 doc = text "Unfolding of" <+> ppr name
879 get_in_scope_ids -- Urgh; but just for linting
881 do { env <- getGblEnv
882 ; case if_rec_types env of {
883 Nothing -> return [] ;
884 Just (_, get_env) -> do
885 { type_env <- get_env
886 ; return (typeEnvIds type_env) }}}
891 %************************************************************************
895 %************************************************************************
898 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
899 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
900 = bindIfaceId bndr thing_inside
901 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
902 = bindIfaceTyVar bndr thing_inside
904 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
905 bindIfaceBndrs [] thing_inside = thing_inside []
906 bindIfaceBndrs (b:bs) thing_inside
907 = bindIfaceBndr b $ \ b' ->
908 bindIfaceBndrs bs $ \ bs' ->
909 thing_inside (b':bs')
911 -----------------------
912 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
913 bindIfaceId (occ, ty) thing_inside
914 = do { name <- newIfaceName occ
915 ; ty' <- tcIfaceType ty
916 ; let { id = mkLocalId name ty' }
917 ; extendIfaceIdEnv [id] (thing_inside id) }
919 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
920 bindIfaceIds bndrs thing_inside
921 = do { names <- newIfaceNames occs
922 ; tys' <- mappM tcIfaceType tys
923 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
924 ; extendIfaceIdEnv ids (thing_inside ids) }
926 (occs,tys) = unzip bndrs
929 -----------------------
930 newExtCoreBndr :: Module -> (OccName, IfaceType) -> IfL Id
931 newExtCoreBndr mod (occ, ty)
932 = do { name <- newGlobalBinder mod occ Nothing noSrcLoc
933 ; ty' <- tcIfaceType ty
934 ; return (mkLocalId name ty') }
936 -----------------------
937 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
938 bindIfaceTyVar (occ,kind) thing_inside
939 = do { name <- newIfaceName occ
940 ; let tyvar = mk_iface_tyvar name kind
941 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
943 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
944 bindIfaceTyVars bndrs thing_inside
945 = do { names <- newIfaceNames occs
946 ; let tyvars = zipWith mk_iface_tyvar names kinds
947 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
949 (occs,kinds) = unzip bndrs
951 mk_iface_tyvar name kind = mkTyVar name (tcIfaceKind kind)