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(..),
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 Monad ( liftM )
81 An IfaceDecl is populated with RdrNames, and these are not renamed to
82 Names before typechecking, because there should be no scope errors etc.
84 -- For (b) consider: f = $(...h....)
85 -- where h is imported, and calls f via an hi-boot file.
86 -- This is bad! But it is not seen as a staging error, because h
87 -- is indeed imported. We don't want the type-checker to black-hole
88 -- when simplifying and compiling the splice!
90 -- Simple solution: discard any unfolding that mentions a variable
91 -- bound in this module (and hence not yet processed).
92 -- The discarding happens when forkM finds a type error.
94 %************************************************************************
96 %* tcImportDecl is the key function for "faulting in" *
99 %************************************************************************
101 The main idea is this. We are chugging along type-checking source code, and
102 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
103 it in the EPS type envt. So it
105 2 gets the decl for GHC.Base.map
106 3 typechecks it via tcIfaceDecl
107 4 and adds it to the type env in the EPS
109 Note that DURING STEP 4, we may find that map's type mentions a type
110 constructor that also
112 Notice that for imported things we read the current version from the EPS
113 mutable variable. This is important in situations like
115 where the code that e1 expands to might import some defns that
116 also turn out to be needed by the code that e2 expands to.
119 tcImportDecl :: Name -> TcM TyThing
120 -- Entry point for *source-code* uses of importDecl
122 | Just thing <- wiredInNameTyThing_maybe name
123 = do { initIfaceTcRn (loadWiredInHomeIface name)
126 = do { traceIf (text "tcImportDecl" <+> ppr name)
127 ; mb_thing <- initIfaceTcRn (importDecl name)
129 Succeeded thing -> return thing
130 Failed err -> failWithTc err }
132 checkWiredInTyCon :: TyCon -> TcM ()
133 -- Ensure that the home module of the TyCon (and hence its instances)
134 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
135 -- in which case this is a no-op.
137 | not (isWiredInName tc_name)
140 = do { mod <- getModule
141 ; if nameIsLocalOrFrom mod tc_name then
142 -- Don't look for (non-existent) Float.hi when
143 -- compiling Float.lhs, which mentions Float of course
145 else -- A bit yukky to call initIfaceTcRn here
146 initIfaceTcRn (loadWiredInHomeIface tc_name)
149 tc_name = tyConName tc
151 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
152 -- Get the TyThing for this Name from an interface file
153 -- It's not a wired-in thing -- the caller caught that
155 = ASSERT( not (isWiredInName name) )
158 -- Load the interface, which should populate the PTE
159 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
161 Failed err_msg -> return (Failed err_msg) ;
162 Succeeded iface -> do
164 -- Now look it up again; this time we should find it
166 ; case lookupTypeEnv (eps_PTE eps) name of
167 Just thing -> return (Succeeded thing)
168 Nothing -> return (Failed not_found_msg)
171 nd_doc = ptext SLIT("Need decl for") <+> ppr name
172 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+>
173 pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
174 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
175 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
178 %************************************************************************
180 Type-checking a complete interface
182 %************************************************************************
184 Suppose we discover we don't need to recompile. Then we must type
185 check the old interface file. This is a bit different to the
186 incremental type checking we do as we suck in interface files. Instead
187 we do things similarly as when we are typechecking source decls: we
188 bring into scope the type envt for the interface all at once, using a
189 knot. Remember, the decls aren't necessarily in dependency order --
190 and even if they were, the type decls might be mutually recursive.
193 typecheckIface :: ModIface -- Get the decls from here
194 -> TcRnIf gbl lcl ModDetails
196 = initIfaceTc iface $ \ tc_env_var -> do
197 -- The tc_env_var is freshly allocated, private to
198 -- type-checking this particular interface
199 { -- Get the right set of decls and rules. If we are compiling without -O
200 -- we discard pragmas before typechecking, so that we don't "see"
201 -- information that we shouldn't. From a versioning point of view
202 -- It's not actually *wrong* to do so, but in fact GHCi is unable
203 -- to handle unboxed tuples, so it must not see unfoldings.
204 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
206 -- Load & typecheck the decls
207 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
209 ; let type_env = mkNameEnv decl_things
210 ; writeMutVar tc_env_var type_env
212 -- Now do those rules and instances
213 ; let { rules | ignore_prags = []
214 | otherwise = mi_rules iface
215 ; dfuns = mi_insts iface
217 ; dfuns <- mapM tcIfaceInst dfuns
218 ; rules <- mapM tcIfaceRule rules
221 ; exports <- ifaceExportNames (mi_exports iface)
224 ; return (ModDetails { md_types = type_env,
227 md_exports = exports })
232 %************************************************************************
234 Type and class declarations
236 %************************************************************************
239 tcHiBootIface :: Module -> TcRn ModDetails
240 -- Load the hi-boot iface for the module being compiled,
241 -- if it indeed exists in the transitive closure of imports
242 -- Return the ModDetails, empty if no hi-boot iface
244 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
247 ; if not (isOneShot mode)
248 -- In --make and interactive mode, if this module has an hs-boot file
249 -- we'll have compiled it already, and it'll be in the HPT
251 -- We check wheher the interface is a *boot* interface.
252 -- It can happen (when using GHC from Visual Studio) that we
253 -- compile a module in TypecheckOnly mode, with a stable,
254 -- fully-populated HPT. In that case the boot interface isn't there
255 -- (it's been replaced by the mother module) so we can't check it.
256 -- And that's fine, because if M's ModInfo is in the HPT, then
257 -- it's been compiled once, and we don't need to check the boot iface
258 then do { hpt <- getHpt
259 ; case lookupUFM hpt (moduleName mod) of
260 Just info | mi_boot (hm_iface info)
261 -> return (hm_details info)
262 other -> return emptyModDetails }
265 -- OK, so we're in one-shot mode.
266 -- In that case, we're read all the direct imports by now,
267 -- so eps_is_boot will record if any of our imports mention us by
268 -- way of hi-boot file
270 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
271 Nothing -> return emptyModDetails ; -- The typical case
273 Just (_, False) -> failWithTc moduleLoop ;
274 -- Someone below us imported us!
275 -- This is a loop with no hi-boot in the way
277 Just (_mod, True) -> -- There's a hi-boot interface below us
279 do { read_result <- findAndReadIface
283 ; case read_result of
284 Failed err -> failWithTc (elaborate err)
285 Succeeded (iface, _path) -> typecheckIface iface
288 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
289 <+> ptext SLIT("to compare against the Real Thing")
291 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
292 <+> ptext SLIT("depends on itself")
294 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
295 quotes (ppr mod) <> colon) 4 err
299 %************************************************************************
301 Type and class declarations
303 %************************************************************************
305 When typechecking a data type decl, we *lazily* (via forkM) typecheck
306 the constructor argument types. This is in the hope that we may never
307 poke on those argument types, and hence may never need to load the
308 interface files for types mentioned in the arg types.
311 data Foo.S = MkS Baz.T
312 Mabye we can get away without even loading the interface for Baz!
314 This is not just a performance thing. Suppose we have
315 data Foo.S = MkS Baz.T
316 data Baz.T = MkT Foo.S
317 (in different interface files, of course).
318 Now, first we load and typecheck Foo.S, and add it to the type envt.
319 If we do explore MkS's argument, we'll load and typecheck Baz.T.
320 If we explore MkT's argument we'll find Foo.S already in the envt.
322 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
323 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
324 which isn't done yet.
326 All very cunning. However, there is a rather subtle gotcha which bit
327 me when developing this stuff. When we typecheck the decl for S, we
328 extend the type envt with S, MkS, and all its implicit Ids. Suppose
329 (a bug, but it happened) that the list of implicit Ids depended in
330 turn on the constructor arg types. Then the following sequence of
332 * we build a thunk <t> for the constructor arg tys
333 * we build a thunk for the extended type environment (depends on <t>)
334 * we write the extended type envt into the global EPS mutvar
336 Now we look something up in the type envt
338 * which reads the global type envt out of the global EPS mutvar
339 * but that depends in turn on <t>
341 It's subtle, because, it'd work fine if we typechecked the constructor args
342 eagerly -- they don't need the extended type envt. They just get the extended
343 type envt by accident, because they look at it later.
345 What this means is that the implicitTyThings MUST NOT DEPEND on any of
350 tcIfaceDecl :: IfaceDecl -> IfL TyThing
352 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
353 = do { name <- lookupIfaceTop occ_name
354 ; ty <- tcIfaceType iface_type
355 ; info <- tcIdInfo name ty info
356 ; return (AnId (mkVanillaGlobal name ty info)) }
358 tcIfaceDecl (IfaceData {ifName = occ_name,
360 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
363 ifGeneric = want_generic,
364 ifFamInst = mb_family })
365 = do { tc_name <- lookupIfaceTop occ_name
366 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
368 { tycon <- fixM ( \ tycon -> do
369 { stupid_theta <- tcIfaceCtxt ctxt
372 Nothing -> return Nothing
374 do { famTyCon <- tcIfaceTyCon fam
375 ; insttys <- mapM tcIfaceType tys
376 ; return $ Just (famTyCon, insttys)
378 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
379 ; buildAlgTyCon tc_name tyvars stupid_theta
380 cons is_rec want_generic gadt_syn famInst
382 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
383 ; return (ATyCon tycon)
386 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
387 ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty})
388 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
389 { tc_name <- lookupIfaceTop occ_name
390 ; rhs_tyki <- tcIfaceType rdr_rhs_ty
391 ; let rhs = if isOpen then OpenSynTyCon rhs_tyki
392 else SynonymTyCon rhs_tyki
393 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs))
396 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
397 ifFDs = rdr_fds, ifSigs = rdr_sigs,
399 -- ToDo: in hs-boot files we should really treat abstract classes specially,
400 -- as we do abstract tycons
401 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
402 { cls_name <- lookupIfaceTop occ_name
403 ; ctxt <- tcIfaceCtxt rdr_ctxt
404 ; sigs <- mappM tc_sig rdr_sigs
405 ; fds <- mappM tc_fd rdr_fds
406 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec
407 ; return (AClass cls) }
409 tc_sig (IfaceClassOp occ dm rdr_ty)
410 = do { op_name <- lookupIfaceTop occ
411 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
412 -- Must be done lazily for just the same reason as the
413 -- context of a data decl: the type sig might mention the
414 -- class being defined
415 ; return (op_name, dm, op_ty) }
417 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
419 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
420 ; tvs2' <- mappM tcIfaceTyVar tvs2
421 ; return (tvs1', tvs2') }
423 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
424 = do { name <- lookupIfaceTop rdr_name
425 ; return (ATyCon (mkForeignTyCon name ext_name
428 tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
430 IfAbstractTyCon -> return mkAbstractTyConRhs
431 IfOpenDataTyCon -> return mkOpenDataTyConRhs
432 IfOpenNewTyCon -> return mkOpenNewTyConRhs
433 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
434 ; return (mkDataTyConRhs data_cons) }
435 IfNewTyCon con -> do { data_con <- tc_con_decl con
436 ; mkNewTyConRhs tycon_name tycon data_con }
438 tc_con_decl (IfCon { ifConInfix = is_infix,
439 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
440 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
441 ifConArgTys = args, ifConFields = field_lbls,
442 ifConStricts = stricts})
443 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
444 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
445 { name <- lookupIfaceTop occ
446 ; eq_spec <- tcIfaceEqSpec spec
447 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
448 -- At one stage I thought that this context checking *had*
449 -- to be lazy, because of possible mutual recursion between the
450 -- type and the classe:
452 -- class Real a where { toRat :: a -> Ratio Integer }
453 -- data (Real a) => Ratio a = ...
454 -- But now I think that the laziness in checking class ops breaks
455 -- the loop, so no laziness needed
457 -- Read the argument types, but lazily to avoid faulting in
458 -- the component types unless they are really needed
459 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
460 ; lbl_names <- mappM lookupIfaceTop field_lbls
462 ; buildDataCon name is_infix {- Not infix -}
464 univ_tyvars ex_tyvars
468 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
473 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
474 ; ty <- tcIfaceType if_ty
479 %************************************************************************
483 %************************************************************************
486 tcIfaceInst :: IfaceInst -> IfL Instance
487 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
488 ifInstCls = cls, ifInstTys = mb_tcs,
490 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
491 tcIfaceExtId (LocalTop dfun_occ)
492 ; cls' <- lookupIfaceExt cls
493 ; mb_tcs' <- mapM do_tc mb_tcs
494 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
496 do_tc Nothing = return Nothing
497 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
501 %************************************************************************
505 %************************************************************************
507 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
508 are in the type environment. However, remember that typechecking a Rule may
509 (as a side effect) augment the type envt, and so we may need to iterate the process.
512 tcIfaceRule :: IfaceRule -> IfL CoreRule
513 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
514 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
516 = do { fn' <- lookupIfaceExt fn
517 ; ~(bndrs', args', rhs') <-
518 -- Typecheck the payload lazily, in the hope it'll never be looked at
519 forkM (ptext SLIT("Rule") <+> ftext name) $
520 bindIfaceBndrs bndrs $ \ bndrs' ->
521 do { args' <- mappM tcIfaceExpr args
522 ; rhs' <- tcIfaceExpr rhs
523 ; return (bndrs', args', rhs') }
524 ; mb_tcs <- mapM ifTopFreeName args
525 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
526 ru_bndrs = bndrs', ru_args = args',
527 ru_rhs = rhs', ru_orph = orph,
529 ru_local = isLocalIfaceExtName fn }) }
531 -- This function *must* mirror exactly what Rules.topFreeName does
532 -- We could have stored the ru_rough field in the iface file
533 -- but that would be redundant, I think.
534 -- The only wrinkle is that we must not be deceived by
535 -- type syononyms at the top of a type arg. Since
536 -- we can't tell at this point, we are careful not
537 -- to write them out in coreRuleToIfaceRule
538 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
539 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
540 = do { n <- lookupIfaceTc tc
542 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
543 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
545 ifTopFreeName other = return Nothing
549 %************************************************************************
553 %************************************************************************
556 tcIfaceType :: IfaceType -> IfL Type
557 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
558 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
559 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
560 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
561 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
562 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
564 tcIfaceTypes tys = mapM tcIfaceType tys
566 -----------------------------------------
567 tcIfacePredType :: IfacePredType -> IfL PredType
568 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
569 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
570 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
572 -----------------------------------------
573 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
574 tcIfaceCtxt sts = mappM tcIfacePredType sts
578 %************************************************************************
582 %************************************************************************
585 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
586 tcIfaceExpr (IfaceType ty)
587 = tcIfaceType ty `thenM` \ ty' ->
590 tcIfaceExpr (IfaceLcl name)
591 = tcIfaceLclId name `thenM` \ id ->
594 tcIfaceExpr (IfaceExt gbl)
595 = tcIfaceExtId gbl `thenM` \ id ->
598 tcIfaceExpr (IfaceLit lit)
601 tcIfaceExpr (IfaceFCall cc ty)
602 = tcIfaceType ty `thenM` \ ty' ->
603 newUnique `thenM` \ u ->
604 returnM (Var (mkFCallId u cc ty'))
606 tcIfaceExpr (IfaceTuple boxity args)
607 = mappM tcIfaceExpr args `thenM` \ args' ->
609 -- Put the missing type arguments back in
610 con_args = map (Type . exprType) args' ++ args'
612 returnM (mkApps (Var con_id) con_args)
615 con_id = dataConWorkId (tupleCon boxity arity)
618 tcIfaceExpr (IfaceLam bndr body)
619 = bindIfaceBndr bndr $ \ bndr' ->
620 tcIfaceExpr body `thenM` \ body' ->
621 returnM (Lam bndr' body')
623 tcIfaceExpr (IfaceApp fun arg)
624 = tcIfaceExpr fun `thenM` \ fun' ->
625 tcIfaceExpr arg `thenM` \ arg' ->
626 returnM (App fun' arg')
628 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
629 = tcIfaceExpr scrut `thenM` \ scrut' ->
630 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
632 scrut_ty = exprType scrut'
633 case_bndr' = mkLocalId case_bndr_name scrut_ty
634 tc_app = splitTyConApp scrut_ty
635 -- NB: Won't always succeed (polymoprhic case)
636 -- but won't be demanded in those cases
637 -- NB: not tcSplitTyConApp; we are looking at Core here
638 -- look through non-rec newtypes to find the tycon that
639 -- corresponds to the datacon in this case alternative
641 extendIfaceIdEnv [case_bndr'] $
642 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
643 tcIfaceType ty `thenM` \ ty' ->
644 returnM (Case scrut' case_bndr' ty' alts')
646 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
647 = tcIfaceExpr rhs `thenM` \ rhs' ->
648 bindIfaceId bndr $ \ bndr' ->
649 tcIfaceExpr body `thenM` \ body' ->
650 returnM (Let (NonRec bndr' rhs') body')
652 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
653 = bindIfaceIds bndrs $ \ bndrs' ->
654 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
655 tcIfaceExpr body `thenM` \ body' ->
656 returnM (Let (Rec (bndrs' `zip` rhss')) body')
658 (bndrs, rhss) = unzip pairs
660 tcIfaceExpr (IfaceCast expr co) = do
661 expr' <- tcIfaceExpr expr
662 co' <- tcIfaceType co
663 returnM (Cast expr' co')
665 tcIfaceExpr (IfaceNote note expr)
666 = tcIfaceExpr expr `thenM` \ expr' ->
668 IfaceInlineMe -> returnM (Note InlineMe expr')
669 IfaceSCC cc -> returnM (Note (SCC cc) expr')
670 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
672 -------------------------
673 tcIfaceAlt _ (IfaceDefault, names, rhs)
674 = ASSERT( null names )
675 tcIfaceExpr rhs `thenM` \ rhs' ->
676 returnM (DEFAULT, [], rhs')
678 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
679 = ASSERT( null names )
680 tcIfaceExpr rhs `thenM` \ rhs' ->
681 returnM (LitAlt lit, [], rhs')
683 -- A case alternative is made quite a bit more complicated
684 -- by the fact that we omit type annotations because we can
685 -- work them out. True enough, but its not that easy!
686 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
687 = do { let tycon_mod = nameModule (tyConName tycon)
688 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
689 ; ASSERT2( con `elem` tyConDataCons tycon,
690 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
691 tcIfaceDataAlt con inst_tys arg_strs rhs }
693 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
694 = ASSERT( isTupleTyCon tycon )
695 do { let [data_con] = tyConDataCons tycon
696 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
698 tcIfaceDataAlt con inst_tys arg_strs rhs
699 = do { us <- newUniqueSupply
700 ; let uniqs = uniqsFromSupply us
701 ; let (ex_tvs, co_tvs, arg_ids)
702 = dataConRepFSInstPat arg_strs uniqs con inst_tys
703 all_tvs = ex_tvs ++ co_tvs
705 ; rhs' <- extendIfaceTyVarEnv all_tvs $
706 extendIfaceIdEnv arg_ids $
708 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
713 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
714 tcExtCoreBindings [] = return []
715 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
717 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
718 do_one (IfaceNonRec bndr rhs) thing_inside
719 = do { rhs' <- tcIfaceExpr rhs
720 ; bndr' <- newExtCoreBndr bndr
721 ; extendIfaceIdEnv [bndr'] $ do
722 { core_binds <- thing_inside
723 ; return (NonRec bndr' rhs' : core_binds) }}
725 do_one (IfaceRec pairs) thing_inside
726 = do { bndrs' <- mappM newExtCoreBndr bndrs
727 ; extendIfaceIdEnv bndrs' $ do
728 { rhss' <- mappM tcIfaceExpr rhss
729 ; core_binds <- thing_inside
730 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
732 (bndrs,rhss) = unzip pairs
736 %************************************************************************
740 %************************************************************************
743 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
744 tcIdInfo name ty NoInfo = return vanillaIdInfo
745 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
747 -- Set the CgInfo to something sensible but uninformative before
748 -- we start; default assumption is that it has CAFs
749 init_info = vanillaIdInfo
751 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
752 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
753 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
755 -- The next two are lazy, so they don't transitively suck stuff in
756 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
757 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
758 tcPrag info (HsUnfold expr)
759 = tcPragExpr name expr `thenM` \ maybe_expr' ->
761 -- maybe_expr' doesn't get looked at if the unfolding
762 -- is never inspected; so the typecheck doesn't even happen
763 unfold_info = case maybe_expr' of
764 Nothing -> noUnfolding
765 Just expr' -> mkTopUnfolding expr'
767 returnM (info `setUnfoldingInfoLazily` unfold_info)
771 tcWorkerInfo ty info wkr arity
772 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
774 -- We return without testing maybe_wkr_id, but as soon as info is
775 -- looked at we will test it. That's ok, because its outside the
776 -- knot; and there seems no big reason to further defer the
777 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
778 -- over the unfolding until it's actually used does seem worth while.)
779 ; us <- newUniqueSupply
781 ; returnM (case mb_wkr_id of
783 Just wkr_id -> add_wkr_info us wkr_id info) }
785 doc = text "Worker for" <+> ppr wkr
786 add_wkr_info us wkr_id info
787 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
788 `setWorkerInfo` HasWorker wkr_id arity
790 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
792 -- We are relying here on strictness info always appearing
793 -- before worker info, fingers crossed ....
794 strict_sig = case newStrictnessInfo info of
796 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
799 For unfoldings we try to do the job lazily, so that we never type check
800 an unfolding that isn't going to be looked at.
803 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
806 tcIfaceExpr expr `thenM` \ core_expr' ->
808 -- Check for type consistency in the unfolding
809 ifOptM Opt_DoCoreLinting (
810 get_in_scope_ids `thenM` \ in_scope ->
811 case lintUnfolding noSrcLoc in_scope core_expr' of
812 Nothing -> returnM ()
813 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
818 doc = text "Unfolding of" <+> ppr name
819 get_in_scope_ids -- Urgh; but just for linting
821 do { env <- getGblEnv
822 ; case if_rec_types env of {
823 Nothing -> return [] ;
824 Just (_, get_env) -> do
825 { type_env <- get_env
826 ; return (typeEnvIds type_env) }}}
831 %************************************************************************
833 Getting from Names to TyThings
835 %************************************************************************
838 tcIfaceGlobal :: Name -> IfL TyThing
840 | Just thing <- wiredInNameTyThing_maybe name
841 -- Wired-in things include TyCons, DataCons, and Ids
842 = do { loadWiredInHomeIface name; return thing }
843 -- Even though we are in an interface file, we want to make
844 -- sure its instances are loaded (imagine f :: Double -> Double)
845 -- and its RULES are loaded too
847 = do { (eps,hpt) <- getEpsAndHpt
849 ; case lookupType dflags hpt (eps_PTE eps) name of {
850 Just thing -> return thing ;
854 ; case if_rec_types env of {
855 Just (mod, get_type_env)
856 | nameIsLocalOrFrom mod name
857 -> do -- It's defined in the module being compiled
858 { type_env <- setLclEnv () get_type_env -- yuk
859 ; case lookupNameEnv type_env name of
860 Just thing -> return thing
861 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
862 (ppr name $$ ppr type_env) }
866 { mb_thing <- importDecl name -- It's imported; go get it
868 Failed err -> failIfM err
869 Succeeded thing -> return thing
872 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
873 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
874 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
875 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
876 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
877 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
878 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
879 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
880 ; thing <- tcIfaceGlobal name
881 ; return (check_tc (tyThingTyCon thing)) }
884 check_tc tc = case toIfaceTyCon (error "urk") tc of
886 other -> pprTrace "check_tc" (ppr tc) tc
890 -- we should be okay just returning Kind constructors without extra loading
891 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
892 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
893 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
894 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
895 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
897 -- Even though we are in an interface file, we want to make
898 -- sure the instances and RULES of this tycon are loaded
899 -- Imagine: f :: Double -> Double
900 tcWiredInTyCon :: TyCon -> IfL TyCon
901 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
904 tcIfaceClass :: IfaceExtName -> IfL Class
905 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
906 ; thing <- tcIfaceGlobal name
907 ; return (tyThingClass thing) }
909 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
910 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
911 ; thing <- tcIfaceGlobal name
913 ADataCon dc -> return dc
914 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
916 tcIfaceExtId :: IfaceExtName -> IfL Id
917 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
918 ; thing <- tcIfaceGlobal name
921 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
924 %************************************************************************
928 %************************************************************************
931 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
932 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
933 = bindIfaceId bndr thing_inside
934 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
935 = bindIfaceTyVar bndr thing_inside
937 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
938 bindIfaceBndrs [] thing_inside = thing_inside []
939 bindIfaceBndrs (b:bs) thing_inside
940 = bindIfaceBndr b $ \ b' ->
941 bindIfaceBndrs bs $ \ bs' ->
942 thing_inside (b':bs')
944 -----------------------
945 bindIfaceId :: IfaceIdBndr -> (Id -> IfL a) -> IfL a
946 bindIfaceId (occ, ty) thing_inside
947 = do { name <- newIfaceName (mkVarOccFS occ)
948 ; ty' <- tcIfaceType ty
949 ; let { id = mkLocalId name ty' }
950 ; extendIfaceIdEnv [id] (thing_inside id) }
952 bindIfaceIds :: [IfaceIdBndr] -> ([Id] -> IfL a) -> IfL a
953 bindIfaceIds bndrs thing_inside
954 = do { names <- newIfaceNames (map mkVarOccFS occs)
955 ; tys' <- mappM tcIfaceType tys
956 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
957 ; extendIfaceIdEnv ids (thing_inside ids) }
959 (occs,tys) = unzip bndrs
962 -----------------------
963 newExtCoreBndr :: IfaceIdBndr -> IfL Id
964 newExtCoreBndr (var, ty)
965 = do { mod <- getIfModule
966 ; name <- newGlobalBinder mod (mkVarOccFS var) Nothing noSrcLoc
967 ; ty' <- tcIfaceType ty
968 ; return (mkLocalId name ty') }
970 -----------------------
971 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
972 bindIfaceTyVar (occ,kind) thing_inside
973 = do { name <- newIfaceName (mkTyVarOcc occ)
974 ; tyvar <- mk_iface_tyvar name kind
975 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
977 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
978 bindIfaceTyVars bndrs thing_inside
979 = do { names <- newIfaceNames (map mkTyVarOcc occs)
980 ; tyvars <- zipWithM mk_iface_tyvar names kinds
981 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
983 (occs,kinds) = unzip bndrs
985 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
986 mk_iface_tyvar name ifKind = do { kind <- tcIfaceType ifKind
987 ; return (mkTyVar name kind)