2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcIfaceSig]{Type checking of type signatures in interface files}
8 tcImportDecl, checkWiredInTyCon, tcHiBootIface, typecheckIface,
9 tcIfaceDecl, tcIfaceInst, tcIfaceRule, tcIfaceGlobal,
13 #include "HsVersions.h"
16 import LoadIface ( loadInterface, loadWiredInHomeIface,
17 loadDecls, findAndReadIface )
18 import IfaceEnv ( lookupIfaceTop, lookupIfaceExt, newGlobalBinder,
19 extendIfaceIdEnv, extendIfaceTyVarEnv, newIPName,
20 tcIfaceTyVar, tcIfaceLclId, lookupIfaceTc,
21 newIfaceName, newIfaceNames, ifaceExportNames )
22 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon,
24 mkAbstractTyConRhs, mkOpenDataTyConRhs,
25 mkOpenNewTyConRhs, mkDataTyConRhs, mkNewTyConRhs )
27 import Type ( liftedTypeKind, splitTyConApp, mkTyConApp,
28 liftedTypeKindTyCon, unliftedTypeKindTyCon,
29 openTypeKindTyCon, argTypeKindTyCon,
31 mkTyVarTys, ThetaType )
32 import TypeRep ( Type(..), PredType(..) )
33 import TyCon ( TyCon, tyConName, SynTyConRhs(..),
34 AlgTyConParent(..), setTyConArgPoss )
35 import HscTypes ( ExternalPackageState(..),
36 TyThing(..), tyThingClass, tyThingTyCon,
37 ModIface(..), ModDetails(..), HomeModInfo(..),
38 emptyModDetails, lookupTypeEnv, lookupType, typeEnvIds )
39 import InstEnv ( Instance(..), mkImportedInstance )
41 import CoreUtils ( exprType, dataConRepFSInstPat )
43 import CoreLint ( lintUnfolding )
44 import WorkWrap ( mkWrapper )
45 import Id ( Id, mkVanillaGlobal, mkLocalId )
46 import MkId ( mkFCallId )
47 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
48 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
49 setArityInfo, setInlinePragInfo, setCafInfo,
50 vanillaIdInfo, newStrictnessInfo )
51 import Class ( Class )
52 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
53 import DataCon ( DataCon, dataConWorkId, dataConExTyVars, dataConInstArgTys )
54 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
55 import Var ( TyVar, mkTyVar, tyVarKind )
56 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
57 nameOccName, wiredInNameTyThing_maybe )
59 import OccName ( OccName, mkVarOccFS, mkTyVarOcc, occNameSpace,
60 pprNameSpace, occNameFS )
61 import FastString ( FastString )
62 import Module ( Module, moduleName )
63 import UniqFM ( lookupUFM )
64 import UniqSupply ( initUs_, uniqsFromSupply )
66 import ErrUtils ( Message )
67 import Maybes ( MaybeErr(..) )
68 import SrcLoc ( noSrcLoc )
69 import Util ( zipWithEqual, equalLength, splitAtList )
70 import DynFlags ( DynFlag(..), isOneShot )
72 import List ( elemIndex)
73 import Maybe ( catMaybes )
74 import Monad ( liftM )
83 An IfaceDecl is populated with RdrNames, and these are not renamed to
84 Names before typechecking, because there should be no scope errors etc.
86 -- For (b) consider: f = $(...h....)
87 -- where h is imported, and calls f via an hi-boot file.
88 -- This is bad! But it is not seen as a staging error, because h
89 -- is indeed imported. We don't want the type-checker to black-hole
90 -- when simplifying and compiling the splice!
92 -- Simple solution: discard any unfolding that mentions a variable
93 -- bound in this module (and hence not yet processed).
94 -- The discarding happens when forkM finds a type error.
96 %************************************************************************
98 %* tcImportDecl is the key function for "faulting in" *
101 %************************************************************************
103 The main idea is this. We are chugging along type-checking source code, and
104 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
105 it in the EPS type envt. So it
107 2 gets the decl for GHC.Base.map
108 3 typechecks it via tcIfaceDecl
109 4 and adds it to the type env in the EPS
111 Note that DURING STEP 4, we may find that map's type mentions a type
112 constructor that also
114 Notice that for imported things we read the current version from the EPS
115 mutable variable. This is important in situations like
117 where the code that e1 expands to might import some defns that
118 also turn out to be needed by the code that e2 expands to.
121 tcImportDecl :: Name -> TcM TyThing
122 -- Entry point for *source-code* uses of importDecl
124 | Just thing <- wiredInNameTyThing_maybe name
125 = do { initIfaceTcRn (loadWiredInHomeIface name)
128 = do { traceIf (text "tcImportDecl" <+> ppr name)
129 ; mb_thing <- initIfaceTcRn (importDecl name)
131 Succeeded thing -> return thing
132 Failed err -> failWithTc err }
134 checkWiredInTyCon :: TyCon -> TcM ()
135 -- Ensure that the home module of the TyCon (and hence its instances)
136 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
137 -- in which case this is a no-op.
139 | not (isWiredInName tc_name)
142 = do { mod <- getModule
143 ; if nameIsLocalOrFrom mod tc_name then
144 -- Don't look for (non-existent) Float.hi when
145 -- compiling Float.lhs, which mentions Float of course
147 else -- A bit yukky to call initIfaceTcRn here
148 initIfaceTcRn (loadWiredInHomeIface tc_name)
151 tc_name = tyConName tc
153 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
154 -- Get the TyThing for this Name from an interface file
155 -- It's not a wired-in thing -- the caller caught that
157 = ASSERT( not (isWiredInName name) )
160 -- Load the interface, which should populate the PTE
161 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
163 Failed err_msg -> return (Failed err_msg) ;
164 Succeeded iface -> do
166 -- Now look it up again; this time we should find it
168 ; case lookupTypeEnv (eps_PTE eps) name of
169 Just thing -> return (Succeeded thing)
170 Nothing -> return (Failed not_found_msg)
173 nd_doc = ptext SLIT("Need decl for") <+> ppr name
174 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+>
175 pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
176 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
177 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
180 %************************************************************************
182 Type-checking a complete interface
184 %************************************************************************
186 Suppose we discover we don't need to recompile. Then we must type
187 check the old interface file. This is a bit different to the
188 incremental type checking we do as we suck in interface files. Instead
189 we do things similarly as when we are typechecking source decls: we
190 bring into scope the type envt for the interface all at once, using a
191 knot. Remember, the decls aren't necessarily in dependency order --
192 and even if they were, the type decls might be mutually recursive.
195 typecheckIface :: ModIface -- Get the decls from here
196 -> TcRnIf gbl lcl ModDetails
198 = initIfaceTc iface $ \ tc_env_var -> do
199 -- The tc_env_var is freshly allocated, private to
200 -- type-checking this particular interface
201 { -- Get the right set of decls and rules. If we are compiling without -O
202 -- we discard pragmas before typechecking, so that we don't "see"
203 -- information that we shouldn't. From a versioning point of view
204 -- It's not actually *wrong* to do so, but in fact GHCi is unable
205 -- to handle unboxed tuples, so it must not see unfoldings.
206 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
208 -- Load & typecheck the decls
209 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
211 ; let type_env = mkNameEnv decl_things
212 ; writeMutVar tc_env_var type_env
214 -- Now do those rules and instances
215 ; let { rules | ignore_prags = []
216 | otherwise = mi_rules iface
217 ; dfuns = mi_insts iface
219 ; dfuns <- mapM tcIfaceInst dfuns
220 ; rules <- mapM tcIfaceRule rules
223 ; exports <- ifaceExportNames (mi_exports iface)
226 ; return (ModDetails { md_types = type_env,
229 md_exports = exports })
234 %************************************************************************
236 Type and class declarations
238 %************************************************************************
241 tcHiBootIface :: Module -> TcRn ModDetails
242 -- Load the hi-boot iface for the module being compiled,
243 -- if it indeed exists in the transitive closure of imports
244 -- Return the ModDetails, empty if no hi-boot iface
246 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
249 ; if not (isOneShot mode)
250 -- In --make and interactive mode, if this module has an hs-boot file
251 -- we'll have compiled it already, and it'll be in the HPT
253 -- We check wheher the interface is a *boot* interface.
254 -- It can happen (when using GHC from Visual Studio) that we
255 -- compile a module in TypecheckOnly mode, with a stable,
256 -- fully-populated HPT. In that case the boot interface isn't there
257 -- (it's been replaced by the mother module) so we can't check it.
258 -- And that's fine, because if M's ModInfo is in the HPT, then
259 -- it's been compiled once, and we don't need to check the boot iface
260 then do { hpt <- getHpt
261 ; case lookupUFM hpt (moduleName mod) of
262 Just info | mi_boot (hm_iface info)
263 -> return (hm_details info)
264 other -> return emptyModDetails }
267 -- OK, so we're in one-shot mode.
268 -- In that case, we're read all the direct imports by now,
269 -- so eps_is_boot will record if any of our imports mention us by
270 -- way of hi-boot file
272 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
273 Nothing -> return emptyModDetails ; -- The typical case
275 Just (_, False) -> failWithTc moduleLoop ;
276 -- Someone below us imported us!
277 -- This is a loop with no hi-boot in the way
279 Just (_mod, True) -> -- There's a hi-boot interface below us
281 do { read_result <- findAndReadIface
285 ; case read_result of
286 Failed err -> failWithTc (elaborate err)
287 Succeeded (iface, _path) -> typecheckIface iface
290 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
291 <+> ptext SLIT("to compare against the Real Thing")
293 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
294 <+> ptext SLIT("depends on itself")
296 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
297 quotes (ppr mod) <> colon) 4 err
301 %************************************************************************
303 Type and class declarations
305 %************************************************************************
307 When typechecking a data type decl, we *lazily* (via forkM) typecheck
308 the constructor argument types. This is in the hope that we may never
309 poke on those argument types, and hence may never need to load the
310 interface files for types mentioned in the arg types.
313 data Foo.S = MkS Baz.T
314 Mabye we can get away without even loading the interface for Baz!
316 This is not just a performance thing. Suppose we have
317 data Foo.S = MkS Baz.T
318 data Baz.T = MkT Foo.S
319 (in different interface files, of course).
320 Now, first we load and typecheck Foo.S, and add it to the type envt.
321 If we do explore MkS's argument, we'll load and typecheck Baz.T.
322 If we explore MkT's argument we'll find Foo.S already in the envt.
324 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
325 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
326 which isn't done yet.
328 All very cunning. However, there is a rather subtle gotcha which bit
329 me when developing this stuff. When we typecheck the decl for S, we
330 extend the type envt with S, MkS, and all its implicit Ids. Suppose
331 (a bug, but it happened) that the list of implicit Ids depended in
332 turn on the constructor arg types. Then the following sequence of
334 * we build a thunk <t> for the constructor arg tys
335 * we build a thunk for the extended type environment (depends on <t>)
336 * we write the extended type envt into the global EPS mutvar
338 Now we look something up in the type envt
340 * which reads the global type envt out of the global EPS mutvar
341 * but that depends in turn on <t>
343 It's subtle, because, it'd work fine if we typechecked the constructor args
344 eagerly -- they don't need the extended type envt. They just get the extended
345 type envt by accident, because they look at it later.
347 What this means is that the implicitTyThings MUST NOT DEPEND on any of
352 tcIfaceDecl :: IfaceDecl -> IfL TyThing
354 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
355 = do { name <- lookupIfaceTop occ_name
356 ; ty <- tcIfaceType iface_type
357 ; info <- tcIdInfo name ty info
358 ; return (AnId (mkVanillaGlobal name ty info)) }
360 tcIfaceDecl (IfaceData {ifName = occ_name,
362 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
365 ifGeneric = want_generic,
366 ifFamInst = mb_family })
367 = do { tc_name <- lookupIfaceTop occ_name
368 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
370 { tycon <- fixM ( \ tycon -> do
371 { stupid_theta <- tcIfaceCtxt ctxt
374 Nothing -> return Nothing
376 do { famTyCon <- tcIfaceTyCon fam
377 ; insttys <- mapM tcIfaceType tys
378 ; return $ Just (famTyCon, insttys)
380 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
381 ; buildAlgTyCon tc_name tyvars stupid_theta
382 cons is_rec want_generic gadt_syn famInst
384 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
385 ; return (ATyCon tycon)
388 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
389 ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty})
390 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
391 { tc_name <- lookupIfaceTop occ_name
392 ; rhs_tyki <- tcIfaceType rdr_rhs_ty
393 ; let rhs = if isOpen then OpenSynTyCon rhs_tyki
394 else SynonymTyCon rhs_tyki
395 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs))
398 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name,
399 ifTyVars = tv_bndrs, ifFDs = rdr_fds,
400 ifATs = rdr_ats, ifSigs = rdr_sigs,
402 -- ToDo: in hs-boot files we should really treat abstract classes specially,
403 -- as we do abstract tycons
404 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
405 { cls_name <- lookupIfaceTop occ_name
406 ; ctxt <- tcIfaceCtxt rdr_ctxt
407 ; sigs <- mappM tc_sig rdr_sigs
408 ; fds <- mappM tc_fd rdr_fds
409 ; ats' <- mappM tcIfaceDecl rdr_ats
410 ; let ats = zipWith setTyThingPoss ats' (map ifTyVars rdr_ats)
411 ; cls <- buildClass cls_name tyvars ctxt fds ats sigs tc_isrec
412 ; return (AClass cls) }
414 tc_sig (IfaceClassOp occ dm rdr_ty)
415 = do { op_name <- lookupIfaceTop occ
416 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
417 -- Must be done lazily for just the same reason as the
418 -- context of a data decl: the type sig might mention the
419 -- class being defined
420 ; return (op_name, dm, op_ty) }
422 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
424 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
425 ; tvs2' <- mappM tcIfaceTyVar tvs2
426 ; return (tvs1', tvs2') }
428 -- For each AT argument compute the position of the corresponding class
429 -- parameter in the class head. This will later serve as a permutation
430 -- vector when checking the validity of instance declarations.
431 setTyThingPoss (ATyCon tycon) atTyVars =
432 let classTyVars = map fst tv_bndrs
434 . map ((`elemIndex` classTyVars) . fst)
436 -- There will be no Nothing, as we already passed renaming
438 ATyCon (setTyConArgPoss tycon poss)
439 setTyThingPoss _ _ = panic "TcIface.setTyThingPoss"
441 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
442 = do { name <- lookupIfaceTop rdr_name
443 ; return (ATyCon (mkForeignTyCon name ext_name
446 tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
448 IfAbstractTyCon -> return mkAbstractTyConRhs
449 IfOpenDataTyCon -> return mkOpenDataTyConRhs
450 IfOpenNewTyCon -> return mkOpenNewTyConRhs
451 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
452 ; return (mkDataTyConRhs data_cons) }
453 IfNewTyCon con -> do { data_con <- tc_con_decl con
454 ; mkNewTyConRhs tycon_name tycon data_con }
456 tc_con_decl (IfCon { ifConInfix = is_infix,
457 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
458 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
459 ifConArgTys = args, ifConFields = field_lbls,
460 ifConStricts = stricts})
461 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
462 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
463 { name <- lookupIfaceTop occ
464 ; eq_spec <- tcIfaceEqSpec spec
465 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
466 -- At one stage I thought that this context checking *had*
467 -- to be lazy, because of possible mutual recursion between the
468 -- type and the classe:
470 -- class Real a where { toRat :: a -> Ratio Integer }
471 -- data (Real a) => Ratio a = ...
472 -- But now I think that the laziness in checking class ops breaks
473 -- the loop, so no laziness needed
475 -- Read the argument types, but lazily to avoid faulting in
476 -- the component types unless they are really needed
477 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
478 ; lbl_names <- mappM lookupIfaceTop field_lbls
480 ; buildDataCon name is_infix {- Not infix -}
482 univ_tyvars ex_tyvars
486 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
491 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
492 ; ty <- tcIfaceType if_ty
497 %************************************************************************
501 %************************************************************************
504 tcIfaceInst :: IfaceInst -> IfL Instance
505 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
506 ifInstCls = cls, ifInstTys = mb_tcs,
508 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
509 tcIfaceExtId (LocalTop dfun_occ)
510 ; cls' <- lookupIfaceExt cls
511 ; mb_tcs' <- mapM do_tc mb_tcs
512 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
514 do_tc Nothing = return Nothing
515 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
519 %************************************************************************
523 %************************************************************************
525 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
526 are in the type environment. However, remember that typechecking a Rule may
527 (as a side effect) augment the type envt, and so we may need to iterate the process.
530 tcIfaceRule :: IfaceRule -> IfL CoreRule
531 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
532 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
534 = do { fn' <- lookupIfaceExt fn
535 ; ~(bndrs', args', rhs') <-
536 -- Typecheck the payload lazily, in the hope it'll never be looked at
537 forkM (ptext SLIT("Rule") <+> ftext name) $
538 bindIfaceBndrs bndrs $ \ bndrs' ->
539 do { args' <- mappM tcIfaceExpr args
540 ; rhs' <- tcIfaceExpr rhs
541 ; return (bndrs', args', rhs') }
542 ; mb_tcs <- mapM ifTopFreeName args
543 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
544 ru_bndrs = bndrs', ru_args = args',
545 ru_rhs = rhs', ru_orph = orph,
547 ru_local = isLocalIfaceExtName fn }) }
549 -- This function *must* mirror exactly what Rules.topFreeName does
550 -- We could have stored the ru_rough field in the iface file
551 -- but that would be redundant, I think.
552 -- The only wrinkle is that we must not be deceived by
553 -- type syononyms at the top of a type arg. Since
554 -- we can't tell at this point, we are careful not
555 -- to write them out in coreRuleToIfaceRule
556 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
557 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
558 = do { n <- lookupIfaceTc tc
560 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
561 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
563 ifTopFreeName other = return Nothing
567 %************************************************************************
571 %************************************************************************
574 tcIfaceType :: IfaceType -> IfL Type
575 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
576 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
577 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
578 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
579 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
580 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
582 tcIfaceTypes tys = mapM tcIfaceType tys
584 -----------------------------------------
585 tcIfacePredType :: IfacePredType -> IfL PredType
586 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
587 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
588 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
590 -----------------------------------------
591 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
592 tcIfaceCtxt sts = mappM tcIfacePredType sts
596 %************************************************************************
600 %************************************************************************
603 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
604 tcIfaceExpr (IfaceType ty)
605 = tcIfaceType ty `thenM` \ ty' ->
608 tcIfaceExpr (IfaceLcl name)
609 = tcIfaceLclId name `thenM` \ id ->
612 tcIfaceExpr (IfaceExt gbl)
613 = tcIfaceExtId gbl `thenM` \ id ->
616 tcIfaceExpr (IfaceLit lit)
619 tcIfaceExpr (IfaceFCall cc ty)
620 = tcIfaceType ty `thenM` \ ty' ->
621 newUnique `thenM` \ u ->
622 returnM (Var (mkFCallId u cc ty'))
624 tcIfaceExpr (IfaceTuple boxity args)
625 = mappM tcIfaceExpr args `thenM` \ args' ->
627 -- Put the missing type arguments back in
628 con_args = map (Type . exprType) args' ++ args'
630 returnM (mkApps (Var con_id) con_args)
633 con_id = dataConWorkId (tupleCon boxity arity)
636 tcIfaceExpr (IfaceLam bndr body)
637 = bindIfaceBndr bndr $ \ bndr' ->
638 tcIfaceExpr body `thenM` \ body' ->
639 returnM (Lam bndr' body')
641 tcIfaceExpr (IfaceApp fun arg)
642 = tcIfaceExpr fun `thenM` \ fun' ->
643 tcIfaceExpr arg `thenM` \ arg' ->
644 returnM (App fun' arg')
646 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
647 = tcIfaceExpr scrut `thenM` \ scrut' ->
648 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
650 scrut_ty = exprType scrut'
651 case_bndr' = mkLocalId case_bndr_name scrut_ty
652 tc_app = splitTyConApp scrut_ty
653 -- NB: Won't always succeed (polymoprhic case)
654 -- but won't be demanded in those cases
655 -- NB: not tcSplitTyConApp; we are looking at Core here
656 -- look through non-rec newtypes to find the tycon that
657 -- corresponds to the datacon in this case alternative
659 extendIfaceIdEnv [case_bndr'] $
660 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
661 tcIfaceType ty `thenM` \ ty' ->
662 returnM (Case scrut' case_bndr' ty' alts')
664 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
665 = tcIfaceExpr rhs `thenM` \ rhs' ->
666 bindIfaceId bndr $ \ bndr' ->
667 tcIfaceExpr body `thenM` \ body' ->
668 returnM (Let (NonRec bndr' rhs') body')
670 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
671 = bindIfaceIds bndrs $ \ bndrs' ->
672 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
673 tcIfaceExpr body `thenM` \ body' ->
674 returnM (Let (Rec (bndrs' `zip` rhss')) body')
676 (bndrs, rhss) = unzip pairs
678 tcIfaceExpr (IfaceCast expr co) = do
679 expr' <- tcIfaceExpr expr
680 co' <- tcIfaceType co
681 returnM (Cast expr' co')
683 tcIfaceExpr (IfaceNote note expr)
684 = tcIfaceExpr expr `thenM` \ expr' ->
686 IfaceInlineMe -> returnM (Note InlineMe expr')
687 IfaceSCC cc -> returnM (Note (SCC cc) expr')
688 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
690 -------------------------
691 tcIfaceAlt _ (IfaceDefault, names, rhs)
692 = ASSERT( null names )
693 tcIfaceExpr rhs `thenM` \ rhs' ->
694 returnM (DEFAULT, [], rhs')
696 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
697 = ASSERT( null names )
698 tcIfaceExpr rhs `thenM` \ rhs' ->
699 returnM (LitAlt lit, [], rhs')
701 -- A case alternative is made quite a bit more complicated
702 -- by the fact that we omit type annotations because we can
703 -- work them out. True enough, but its not that easy!
704 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
705 = do { let tycon_mod = nameModule (tyConName tycon)
706 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
707 ; ASSERT2( con `elem` tyConDataCons tycon,
708 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
709 tcIfaceDataAlt con inst_tys arg_strs rhs }
711 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
712 = ASSERT( isTupleTyCon tycon )
713 do { let [data_con] = tyConDataCons tycon
714 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
716 tcIfaceDataAlt con inst_tys arg_strs rhs
717 = do { us <- newUniqueSupply
718 ; let uniqs = uniqsFromSupply us
719 ; let (ex_tvs, co_tvs, arg_ids)
720 = dataConRepFSInstPat arg_strs uniqs con inst_tys
721 all_tvs = ex_tvs ++ co_tvs
723 ; rhs' <- extendIfaceTyVarEnv all_tvs $
724 extendIfaceIdEnv arg_ids $
726 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
731 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
732 tcExtCoreBindings [] = return []
733 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
735 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
736 do_one (IfaceNonRec bndr rhs) thing_inside
737 = do { rhs' <- tcIfaceExpr rhs
738 ; bndr' <- newExtCoreBndr bndr
739 ; extendIfaceIdEnv [bndr'] $ do
740 { core_binds <- thing_inside
741 ; return (NonRec bndr' rhs' : core_binds) }}
743 do_one (IfaceRec pairs) thing_inside
744 = do { bndrs' <- mappM newExtCoreBndr bndrs
745 ; extendIfaceIdEnv bndrs' $ do
746 { rhss' <- mappM tcIfaceExpr rhss
747 ; core_binds <- thing_inside
748 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
750 (bndrs,rhss) = unzip pairs
754 %************************************************************************
758 %************************************************************************
761 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
762 tcIdInfo name ty NoInfo = return vanillaIdInfo
763 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
765 -- Set the CgInfo to something sensible but uninformative before
766 -- we start; default assumption is that it has CAFs
767 init_info = vanillaIdInfo
769 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
770 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
771 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
773 -- The next two are lazy, so they don't transitively suck stuff in
774 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
775 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
776 tcPrag info (HsUnfold expr)
777 = tcPragExpr name expr `thenM` \ maybe_expr' ->
779 -- maybe_expr' doesn't get looked at if the unfolding
780 -- is never inspected; so the typecheck doesn't even happen
781 unfold_info = case maybe_expr' of
782 Nothing -> noUnfolding
783 Just expr' -> mkTopUnfolding expr'
785 returnM (info `setUnfoldingInfoLazily` unfold_info)
789 tcWorkerInfo ty info wkr arity
790 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
792 -- We return without testing maybe_wkr_id, but as soon as info is
793 -- looked at we will test it. That's ok, because its outside the
794 -- knot; and there seems no big reason to further defer the
795 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
796 -- over the unfolding until it's actually used does seem worth while.)
797 ; us <- newUniqueSupply
799 ; returnM (case mb_wkr_id of
801 Just wkr_id -> add_wkr_info us wkr_id info) }
803 doc = text "Worker for" <+> ppr wkr
804 add_wkr_info us wkr_id info
805 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
806 `setWorkerInfo` HasWorker wkr_id arity
808 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
810 -- We are relying here on strictness info always appearing
811 -- before worker info, fingers crossed ....
812 strict_sig = case newStrictnessInfo info of
814 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
817 For unfoldings we try to do the job lazily, so that we never type check
818 an unfolding that isn't going to be looked at.
821 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
824 tcIfaceExpr expr `thenM` \ core_expr' ->
826 -- Check for type consistency in the unfolding
827 ifOptM Opt_DoCoreLinting (
828 get_in_scope_ids `thenM` \ in_scope ->
829 case lintUnfolding noSrcLoc in_scope core_expr' of
830 Nothing -> returnM ()
831 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
836 doc = text "Unfolding of" <+> ppr name
837 get_in_scope_ids -- Urgh; but just for linting
839 do { env <- getGblEnv
840 ; case if_rec_types env of {
841 Nothing -> return [] ;
842 Just (_, get_env) -> do
843 { type_env <- get_env
844 ; return (typeEnvIds type_env) }}}
849 %************************************************************************
851 Getting from Names to TyThings
853 %************************************************************************
856 tcIfaceGlobal :: Name -> IfL TyThing
858 | Just thing <- wiredInNameTyThing_maybe name
859 -- Wired-in things include TyCons, DataCons, and Ids
860 = do { loadWiredInHomeIface name; return thing }
861 -- Even though we are in an interface file, we want to make
862 -- sure its instances are loaded (imagine f :: Double -> Double)
863 -- and its RULES are loaded too
865 = do { (eps,hpt) <- getEpsAndHpt
867 ; case lookupType dflags hpt (eps_PTE eps) name of {
868 Just thing -> return thing ;
872 ; case if_rec_types env of {
873 Just (mod, get_type_env)
874 | nameIsLocalOrFrom mod name
875 -> do -- It's defined in the module being compiled
876 { type_env <- setLclEnv () get_type_env -- yuk
877 ; case lookupNameEnv type_env name of
878 Just thing -> return thing
879 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
880 (ppr name $$ ppr type_env) }
884 { mb_thing <- importDecl name -- It's imported; go get it
886 Failed err -> failIfM err
887 Succeeded thing -> return thing
890 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
891 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
892 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
893 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
894 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
895 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
896 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
897 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
898 ; thing <- tcIfaceGlobal name
899 ; return (check_tc (tyThingTyCon thing)) }
902 check_tc tc = case toIfaceTyCon (error "urk") tc of
904 other -> pprTrace "check_tc" (ppr tc) tc
908 -- we should be okay just returning Kind constructors without extra loading
909 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
910 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
911 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
912 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
913 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
915 -- Even though we are in an interface file, we want to make
916 -- sure the instances and RULES of this tycon are loaded
917 -- Imagine: f :: Double -> Double
918 tcWiredInTyCon :: TyCon -> IfL TyCon
919 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
922 tcIfaceClass :: IfaceExtName -> IfL Class
923 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
924 ; thing <- tcIfaceGlobal name
925 ; return (tyThingClass thing) }
927 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
928 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
929 ; thing <- tcIfaceGlobal name
931 ADataCon dc -> return dc
932 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
934 tcIfaceExtId :: IfaceExtName -> IfL Id
935 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
936 ; thing <- tcIfaceGlobal name
939 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
942 %************************************************************************
946 %************************************************************************
949 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
950 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
951 = bindIfaceId bndr thing_inside
952 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
953 = bindIfaceTyVar bndr thing_inside
955 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
956 bindIfaceBndrs [] thing_inside = thing_inside []
957 bindIfaceBndrs (b:bs) thing_inside
958 = bindIfaceBndr b $ \ b' ->
959 bindIfaceBndrs bs $ \ bs' ->
960 thing_inside (b':bs')
962 -----------------------
963 bindIfaceId :: IfaceIdBndr -> (Id -> IfL a) -> IfL a
964 bindIfaceId (occ, ty) thing_inside
965 = do { name <- newIfaceName (mkVarOccFS occ)
966 ; ty' <- tcIfaceType ty
967 ; let { id = mkLocalId name ty' }
968 ; extendIfaceIdEnv [id] (thing_inside id) }
970 bindIfaceIds :: [IfaceIdBndr] -> ([Id] -> IfL a) -> IfL a
971 bindIfaceIds bndrs thing_inside
972 = do { names <- newIfaceNames (map mkVarOccFS occs)
973 ; tys' <- mappM tcIfaceType tys
974 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
975 ; extendIfaceIdEnv ids (thing_inside ids) }
977 (occs,tys) = unzip bndrs
980 -----------------------
981 newExtCoreBndr :: IfaceIdBndr -> IfL Id
982 newExtCoreBndr (var, ty)
983 = do { mod <- getIfModule
984 ; name <- newGlobalBinder mod (mkVarOccFS var) Nothing noSrcLoc
985 ; ty' <- tcIfaceType ty
986 ; return (mkLocalId name ty') }
988 -----------------------
989 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
990 bindIfaceTyVar (occ,kind) thing_inside
991 = do { name <- newIfaceName (mkTyVarOcc occ)
992 ; tyvar <- mk_iface_tyvar name kind
993 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
995 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
996 bindIfaceTyVars bndrs thing_inside
997 = do { names <- newIfaceNames (map mkTyVarOcc occs)
998 ; tyvars <- zipWithM mk_iface_tyvar names kinds
999 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
1001 (occs,kinds) = unzip bndrs
1003 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
1004 mk_iface_tyvar name ifKind = do { kind <- tcIfaceType ifKind
1005 ; return (mkTyVar name kind)