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 import HscTypes ( ExternalPackageState(..),
35 TyThing(..), tyThingClass, tyThingTyCon,
36 ModIface(..), ModDetails(..), HomeModInfo(..),
37 emptyModDetails, lookupTypeEnv, lookupType, typeEnvIds )
38 import InstEnv ( Instance(..), mkImportedInstance )
40 import CoreUtils ( exprType, dataConRepFSInstPat )
42 import CoreLint ( lintUnfolding )
43 import WorkWrap ( mkWrapper )
44 import Id ( Id, mkVanillaGlobal, mkLocalId )
45 import MkId ( mkFCallId )
46 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
47 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
48 setArityInfo, setInlinePragInfo, setCafInfo,
49 vanillaIdInfo, newStrictnessInfo )
50 import Class ( Class )
51 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
52 import DataCon ( DataCon, dataConWorkId, dataConExTyVars, dataConInstArgTys )
53 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
54 import Var ( TyVar, mkTyVar, tyVarKind )
55 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
56 nameOccName, wiredInNameTyThing_maybe )
58 import OccName ( OccName, mkVarOccFS, mkTyVarOcc, occNameSpace,
59 pprNameSpace, occNameFS )
60 import FastString ( FastString )
61 import Module ( Module, moduleName )
62 import UniqFM ( lookupUFM )
63 import UniqSupply ( initUs_, uniqsFromSupply )
65 import ErrUtils ( Message )
66 import Maybes ( MaybeErr(..) )
67 import SrcLoc ( noSrcLoc )
68 import Util ( zipWithEqual, equalLength, splitAtList )
69 import DynFlags ( DynFlag(..), isOneShot )
79 An IfaceDecl is populated with RdrNames, and these are not renamed to
80 Names before typechecking, because there should be no scope errors etc.
82 -- For (b) consider: f = $(...h....)
83 -- where h is imported, and calls f via an hi-boot file.
84 -- This is bad! But it is not seen as a staging error, because h
85 -- is indeed imported. We don't want the type-checker to black-hole
86 -- when simplifying and compiling the splice!
88 -- Simple solution: discard any unfolding that mentions a variable
89 -- bound in this module (and hence not yet processed).
90 -- The discarding happens when forkM finds a type error.
92 %************************************************************************
94 %* tcImportDecl is the key function for "faulting in" *
97 %************************************************************************
99 The main idea is this. We are chugging along type-checking source code, and
100 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
101 it in the EPS type envt. So it
103 2 gets the decl for GHC.Base.map
104 3 typechecks it via tcIfaceDecl
105 4 and adds it to the type env in the EPS
107 Note that DURING STEP 4, we may find that map's type mentions a type
108 constructor that also
110 Notice that for imported things we read the current version from the EPS
111 mutable variable. This is important in situations like
113 where the code that e1 expands to might import some defns that
114 also turn out to be needed by the code that e2 expands to.
117 tcImportDecl :: Name -> TcM TyThing
118 -- Entry point for *source-code* uses of importDecl
120 | Just thing <- wiredInNameTyThing_maybe name
121 = do { initIfaceTcRn (loadWiredInHomeIface name)
124 = do { traceIf (text "tcImportDecl" <+> ppr name)
125 ; mb_thing <- initIfaceTcRn (importDecl name)
127 Succeeded thing -> return thing
128 Failed err -> failWithTc err }
130 checkWiredInTyCon :: TyCon -> TcM ()
131 -- Ensure that the home module of the TyCon (and hence its instances)
132 -- are loaded. It might not be a wired-in tycon (see the calls in TcUnify),
133 -- in which case this is a no-op.
135 | not (isWiredInName tc_name)
138 = do { mod <- getModule
139 ; if nameIsLocalOrFrom mod tc_name then
140 -- Don't look for (non-existent) Float.hi when
141 -- compiling Float.lhs, which mentions Float of course
143 else -- A bit yukky to call initIfaceTcRn here
144 initIfaceTcRn (loadWiredInHomeIface tc_name)
147 tc_name = tyConName tc
149 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
150 -- Get the TyThing for this Name from an interface file
151 -- It's not a wired-in thing -- the caller caught that
153 = ASSERT( not (isWiredInName name) )
156 -- Load the interface, which should populate the PTE
157 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
159 Failed err_msg -> return (Failed err_msg) ;
160 Succeeded iface -> do
162 -- Now look it up again; this time we should find it
164 ; case lookupTypeEnv (eps_PTE eps) name of
165 Just thing -> return (Succeeded thing)
166 Nothing -> return (Failed not_found_msg)
169 nd_doc = ptext SLIT("Need decl for") <+> ppr name
170 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+>
171 pprNameSpace (occNameSpace (nameOccName name)) <+> ppr name)
172 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
173 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
176 %************************************************************************
178 Type-checking a complete interface
180 %************************************************************************
182 Suppose we discover we don't need to recompile. Then we must type
183 check the old interface file. This is a bit different to the
184 incremental type checking we do as we suck in interface files. Instead
185 we do things similarly as when we are typechecking source decls: we
186 bring into scope the type envt for the interface all at once, using a
187 knot. Remember, the decls aren't necessarily in dependency order --
188 and even if they were, the type decls might be mutually recursive.
191 typecheckIface :: ModIface -- Get the decls from here
192 -> TcRnIf gbl lcl ModDetails
194 = initIfaceTc iface $ \ tc_env_var -> do
195 -- The tc_env_var is freshly allocated, private to
196 -- type-checking this particular interface
197 { -- Get the right set of decls and rules. If we are compiling without -O
198 -- we discard pragmas before typechecking, so that we don't "see"
199 -- information that we shouldn't. From a versioning point of view
200 -- It's not actually *wrong* to do so, but in fact GHCi is unable
201 -- to handle unboxed tuples, so it must not see unfoldings.
202 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
204 -- Load & typecheck the decls
205 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
207 ; let type_env = mkNameEnv decl_things
208 ; writeMutVar tc_env_var type_env
210 -- Now do those rules and instances
211 ; let { rules | ignore_prags = []
212 | otherwise = mi_rules iface
213 ; dfuns = mi_insts iface
215 ; dfuns <- mapM tcIfaceInst dfuns
216 ; rules <- mapM tcIfaceRule rules
219 ; exports <- ifaceExportNames (mi_exports iface)
222 ; return (ModDetails { md_types = type_env,
225 md_exports = exports })
230 %************************************************************************
232 Type and class declarations
234 %************************************************************************
237 tcHiBootIface :: Module -> TcRn ModDetails
238 -- Load the hi-boot iface for the module being compiled,
239 -- if it indeed exists in the transitive closure of imports
240 -- Return the ModDetails, empty if no hi-boot iface
242 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
245 ; if not (isOneShot mode)
246 -- In --make and interactive mode, if this module has an hs-boot file
247 -- we'll have compiled it already, and it'll be in the HPT
249 -- We check wheher the interface is a *boot* interface.
250 -- It can happen (when using GHC from Visual Studio) that we
251 -- compile a module in TypecheckOnly mode, with a stable,
252 -- fully-populated HPT. In that case the boot interface isn't there
253 -- (it's been replaced by the mother module) so we can't check it.
254 -- And that's fine, because if M's ModInfo is in the HPT, then
255 -- it's been compiled once, and we don't need to check the boot iface
256 then do { hpt <- getHpt
257 ; case lookupUFM hpt (moduleName mod) of
258 Just info | mi_boot (hm_iface info)
259 -> return (hm_details info)
260 other -> return emptyModDetails }
263 -- OK, so we're in one-shot mode.
264 -- In that case, we're read all the direct imports by now,
265 -- so eps_is_boot will record if any of our imports mention us by
266 -- way of hi-boot file
268 ; case lookupUFM (eps_is_boot eps) (moduleName mod) of {
269 Nothing -> return emptyModDetails ; -- The typical case
271 Just (_, False) -> failWithTc moduleLoop ;
272 -- Someone below us imported us!
273 -- This is a loop with no hi-boot in the way
275 Just (_mod, True) -> -- There's a hi-boot interface below us
277 do { read_result <- findAndReadIface
281 ; case read_result of
282 Failed err -> failWithTc (elaborate err)
283 Succeeded (iface, _path) -> typecheckIface iface
286 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
287 <+> ptext SLIT("to compare against the Real Thing")
289 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
290 <+> ptext SLIT("depends on itself")
292 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
293 quotes (ppr mod) <> colon) 4 err
297 %************************************************************************
299 Type and class declarations
301 %************************************************************************
303 When typechecking a data type decl, we *lazily* (via forkM) typecheck
304 the constructor argument types. This is in the hope that we may never
305 poke on those argument types, and hence may never need to load the
306 interface files for types mentioned in the arg types.
309 data Foo.S = MkS Baz.T
310 Mabye we can get away without even loading the interface for Baz!
312 This is not just a performance thing. Suppose we have
313 data Foo.S = MkS Baz.T
314 data Baz.T = MkT Foo.S
315 (in different interface files, of course).
316 Now, first we load and typecheck Foo.S, and add it to the type envt.
317 If we do explore MkS's argument, we'll load and typecheck Baz.T.
318 If we explore MkT's argument we'll find Foo.S already in the envt.
320 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
321 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
322 which isn't done yet.
324 All very cunning. However, there is a rather subtle gotcha which bit
325 me when developing this stuff. When we typecheck the decl for S, we
326 extend the type envt with S, MkS, and all its implicit Ids. Suppose
327 (a bug, but it happened) that the list of implicit Ids depended in
328 turn on the constructor arg types. Then the following sequence of
330 * we build a thunk <t> for the constructor arg tys
331 * we build a thunk for the extended type environment (depends on <t>)
332 * we write the extended type envt into the global EPS mutvar
334 Now we look something up in the type envt
336 * which reads the global type envt out of the global EPS mutvar
337 * but that depends in turn on <t>
339 It's subtle, because, it'd work fine if we typechecked the constructor args
340 eagerly -- they don't need the extended type envt. They just get the extended
341 type envt by accident, because they look at it later.
343 What this means is that the implicitTyThings MUST NOT DEPEND on any of
348 tcIfaceDecl :: IfaceDecl -> IfL TyThing
350 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
351 = do { name <- lookupIfaceTop occ_name
352 ; ty <- tcIfaceType iface_type
353 ; info <- tcIdInfo name ty info
354 ; return (AnId (mkVanillaGlobal name ty info)) }
356 tcIfaceDecl (IfaceData {ifName = occ_name,
358 ifCtxt = ctxt, ifGadtSyntax = gadt_syn,
361 ifGeneric = want_generic })
362 = do { tc_name <- lookupIfaceTop occ_name
363 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
365 { tycon <- fixM ( \ tycon -> do
366 { stupid_theta <- tcIfaceCtxt ctxt
367 ; cons <- tcIfaceDataCons tc_name tycon tyvars rdr_cons
368 ; buildAlgTyCon tc_name tyvars stupid_theta
369 cons is_rec want_generic gadt_syn
371 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
372 ; return (ATyCon tycon)
375 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
376 ifOpenSyn = isOpen, ifSynRhs = rdr_rhs_ty})
377 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
378 { tc_name <- lookupIfaceTop occ_name
379 ; rhs_tyki <- tcIfaceType rdr_rhs_ty
380 ; let rhs = if isOpen then OpenSynTyCon rhs_tyki
381 else SynonymTyCon rhs_tyki
382 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs))
385 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
386 ifFDs = rdr_fds, ifSigs = rdr_sigs,
388 -- ToDo: in hs-boot files we should really treat abstract classes specially,
389 -- as we do abstract tycons
390 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
391 { cls_name <- lookupIfaceTop occ_name
392 ; ctxt <- tcIfaceCtxt rdr_ctxt
393 ; sigs <- mappM tc_sig rdr_sigs
394 ; fds <- mappM tc_fd rdr_fds
395 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec
396 ; return (AClass cls) }
398 tc_sig (IfaceClassOp occ dm rdr_ty)
399 = do { op_name <- lookupIfaceTop occ
400 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
401 -- Must be done lazily for just the same reason as the
402 -- context of a data decl: the type sig might mention the
403 -- class being defined
404 ; return (op_name, dm, op_ty) }
406 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
408 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
409 ; tvs2' <- mappM tcIfaceTyVar tvs2
410 ; return (tvs1', tvs2') }
412 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
413 = do { name <- lookupIfaceTop rdr_name
414 ; return (ATyCon (mkForeignTyCon name ext_name
417 tcIfaceDataCons tycon_name tycon tc_tyvars if_cons
419 IfAbstractTyCon -> return mkAbstractTyConRhs
420 IfOpenDataTyCon -> return mkOpenDataTyConRhs
421 IfOpenNewTyCon -> return mkOpenNewTyConRhs
422 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
423 ; return (mkDataTyConRhs data_cons) }
424 IfNewTyCon con -> do { data_con <- tc_con_decl con
425 ; mkNewTyConRhs tycon_name tycon data_con }
427 tc_con_decl (IfCon { ifConInfix = is_infix,
428 ifConUnivTvs = univ_tvs, ifConExTvs = ex_tvs,
429 ifConOcc = occ, ifConCtxt = ctxt, ifConEqSpec = spec,
430 ifConArgTys = args, ifConFields = field_lbls,
431 ifConStricts = stricts})
432 = bindIfaceTyVars univ_tvs $ \ univ_tyvars -> do
433 bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
434 { name <- lookupIfaceTop occ
435 ; eq_spec <- tcIfaceEqSpec spec
436 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
437 -- At one stage I thought that this context checking *had*
438 -- to be lazy, because of possible mutual recursion between the
439 -- type and the classe:
441 -- class Real a where { toRat :: a -> Ratio Integer }
442 -- data (Real a) => Ratio a = ...
443 -- But now I think that the laziness in checking class ops breaks
444 -- the loop, so no laziness needed
446 -- Read the argument types, but lazily to avoid faulting in
447 -- the component types unless they are really needed
448 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
449 ; lbl_names <- mappM lookupIfaceTop field_lbls
451 ; buildDataCon name is_infix {- Not infix -}
453 univ_tyvars ex_tyvars
457 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
462 do_item (occ, if_ty) = do { tv <- tcIfaceTyVar (occNameFS occ)
463 ; ty <- tcIfaceType if_ty
468 %************************************************************************
472 %************************************************************************
475 tcIfaceInst :: IfaceInst -> IfL Instance
476 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
477 ifInstCls = cls, ifInstTys = mb_tcs,
479 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
480 tcIfaceExtId (LocalTop dfun_occ)
481 ; cls' <- lookupIfaceExt cls
482 ; mb_tcs' <- mapM do_tc mb_tcs
483 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
485 do_tc Nothing = return Nothing
486 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
490 %************************************************************************
494 %************************************************************************
496 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
497 are in the type environment. However, remember that typechecking a Rule may
498 (as a side effect) augment the type envt, and so we may need to iterate the process.
501 tcIfaceRule :: IfaceRule -> IfL CoreRule
502 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
503 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
505 = do { fn' <- lookupIfaceExt fn
506 ; ~(bndrs', args', rhs') <-
507 -- Typecheck the payload lazily, in the hope it'll never be looked at
508 forkM (ptext SLIT("Rule") <+> ftext name) $
509 bindIfaceBndrs bndrs $ \ bndrs' ->
510 do { args' <- mappM tcIfaceExpr args
511 ; rhs' <- tcIfaceExpr rhs
512 ; return (bndrs', args', rhs') }
513 ; mb_tcs <- mapM ifTopFreeName args
514 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
515 ru_bndrs = bndrs', ru_args = args',
516 ru_rhs = rhs', ru_orph = orph,
518 ru_local = isLocalIfaceExtName fn }) }
520 -- This function *must* mirror exactly what Rules.topFreeName does
521 -- We could have stored the ru_rough field in the iface file
522 -- but that would be redundant, I think.
523 -- The only wrinkle is that we must not be deceived by
524 -- type syononyms at the top of a type arg. Since
525 -- we can't tell at this point, we are careful not
526 -- to write them out in coreRuleToIfaceRule
527 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
528 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
529 = do { n <- lookupIfaceTc tc
531 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
532 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
534 ifTopFreeName other = return Nothing
538 %************************************************************************
542 %************************************************************************
545 tcIfaceType :: IfaceType -> IfL Type
546 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
547 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
548 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
549 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkTyConApp tc' ts') }
550 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
551 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
553 tcIfaceTypes tys = mapM tcIfaceType tys
555 -----------------------------------------
556 tcIfacePredType :: IfacePredType -> IfL PredType
557 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
558 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
559 tcIfacePredType (IfaceEqPred t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (EqPred t1' t2') }
561 -----------------------------------------
562 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
563 tcIfaceCtxt sts = mappM tcIfacePredType sts
567 %************************************************************************
571 %************************************************************************
574 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
575 tcIfaceExpr (IfaceType ty)
576 = tcIfaceType ty `thenM` \ ty' ->
579 tcIfaceExpr (IfaceLcl name)
580 = tcIfaceLclId name `thenM` \ id ->
583 tcIfaceExpr (IfaceExt gbl)
584 = tcIfaceExtId gbl `thenM` \ id ->
587 tcIfaceExpr (IfaceLit lit)
590 tcIfaceExpr (IfaceFCall cc ty)
591 = tcIfaceType ty `thenM` \ ty' ->
592 newUnique `thenM` \ u ->
593 returnM (Var (mkFCallId u cc ty'))
595 tcIfaceExpr (IfaceTuple boxity args)
596 = mappM tcIfaceExpr args `thenM` \ args' ->
598 -- Put the missing type arguments back in
599 con_args = map (Type . exprType) args' ++ args'
601 returnM (mkApps (Var con_id) con_args)
604 con_id = dataConWorkId (tupleCon boxity arity)
607 tcIfaceExpr (IfaceLam bndr body)
608 = bindIfaceBndr bndr $ \ bndr' ->
609 tcIfaceExpr body `thenM` \ body' ->
610 returnM (Lam bndr' body')
612 tcIfaceExpr (IfaceApp fun arg)
613 = tcIfaceExpr fun `thenM` \ fun' ->
614 tcIfaceExpr arg `thenM` \ arg' ->
615 returnM (App fun' arg')
617 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
618 = tcIfaceExpr scrut `thenM` \ scrut' ->
619 newIfaceName (mkVarOccFS case_bndr) `thenM` \ case_bndr_name ->
621 scrut_ty = exprType scrut'
622 case_bndr' = mkLocalId case_bndr_name scrut_ty
623 tc_app = splitTyConApp scrut_ty
624 -- NB: Won't always succeed (polymoprhic case)
625 -- but won't be demanded in those cases
626 -- NB: not tcSplitTyConApp; we are looking at Core here
627 -- look through non-rec newtypes to find the tycon that
628 -- corresponds to the datacon in this case alternative
630 extendIfaceIdEnv [case_bndr'] $
631 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
632 tcIfaceType ty `thenM` \ ty' ->
633 returnM (Case scrut' case_bndr' ty' alts')
635 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
636 = tcIfaceExpr rhs `thenM` \ rhs' ->
637 bindIfaceId bndr $ \ bndr' ->
638 tcIfaceExpr body `thenM` \ body' ->
639 returnM (Let (NonRec bndr' rhs') body')
641 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
642 = bindIfaceIds bndrs $ \ bndrs' ->
643 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
644 tcIfaceExpr body `thenM` \ body' ->
645 returnM (Let (Rec (bndrs' `zip` rhss')) body')
647 (bndrs, rhss) = unzip pairs
649 tcIfaceExpr (IfaceCast expr co) = do
650 expr' <- tcIfaceExpr expr
651 co' <- tcIfaceType co
652 returnM (Cast expr' co')
654 tcIfaceExpr (IfaceNote note expr)
655 = tcIfaceExpr expr `thenM` \ expr' ->
657 IfaceInlineMe -> returnM (Note InlineMe expr')
658 IfaceSCC cc -> returnM (Note (SCC cc) expr')
659 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
661 -------------------------
662 tcIfaceAlt _ (IfaceDefault, names, rhs)
663 = ASSERT( null names )
664 tcIfaceExpr rhs `thenM` \ rhs' ->
665 returnM (DEFAULT, [], rhs')
667 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
668 = ASSERT( null names )
669 tcIfaceExpr rhs `thenM` \ rhs' ->
670 returnM (LitAlt lit, [], rhs')
672 -- A case alternative is made quite a bit more complicated
673 -- by the fact that we omit type annotations because we can
674 -- work them out. True enough, but its not that easy!
675 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_strs, rhs)
676 = do { let tycon_mod = nameModule (tyConName tycon)
677 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
678 ; ASSERT2( con `elem` tyConDataCons tycon,
679 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
680 tcIfaceDataAlt con inst_tys arg_strs rhs }
682 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
683 = ASSERT( isTupleTyCon tycon )
684 do { let [data_con] = tyConDataCons tycon
685 ; tcIfaceDataAlt data_con inst_tys arg_occs rhs }
687 tcIfaceDataAlt con inst_tys arg_strs rhs
688 = do { us <- newUniqueSupply
689 ; let uniqs = uniqsFromSupply us
690 ; let (ex_tvs, co_tvs, arg_ids)
691 = dataConRepFSInstPat arg_strs uniqs con inst_tys
692 all_tvs = ex_tvs ++ co_tvs
694 ; rhs' <- extendIfaceTyVarEnv all_tvs $
695 extendIfaceIdEnv arg_ids $
697 ; return (DataAlt con, all_tvs ++ arg_ids, rhs') }
702 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
703 tcExtCoreBindings [] = return []
704 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
706 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
707 do_one (IfaceNonRec bndr rhs) thing_inside
708 = do { rhs' <- tcIfaceExpr rhs
709 ; bndr' <- newExtCoreBndr bndr
710 ; extendIfaceIdEnv [bndr'] $ do
711 { core_binds <- thing_inside
712 ; return (NonRec bndr' rhs' : core_binds) }}
714 do_one (IfaceRec pairs) thing_inside
715 = do { bndrs' <- mappM newExtCoreBndr bndrs
716 ; extendIfaceIdEnv bndrs' $ do
717 { rhss' <- mappM tcIfaceExpr rhss
718 ; core_binds <- thing_inside
719 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
721 (bndrs,rhss) = unzip pairs
725 %************************************************************************
729 %************************************************************************
732 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
733 tcIdInfo name ty NoInfo = return vanillaIdInfo
734 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
736 -- Set the CgInfo to something sensible but uninformative before
737 -- we start; default assumption is that it has CAFs
738 init_info = vanillaIdInfo
740 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
741 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
742 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
744 -- The next two are lazy, so they don't transitively suck stuff in
745 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
746 tcPrag info (HsInline inline_prag) = returnM (info `setInlinePragInfo` inline_prag)
747 tcPrag info (HsUnfold expr)
748 = tcPragExpr name expr `thenM` \ maybe_expr' ->
750 -- maybe_expr' doesn't get looked at if the unfolding
751 -- is never inspected; so the typecheck doesn't even happen
752 unfold_info = case maybe_expr' of
753 Nothing -> noUnfolding
754 Just expr' -> mkTopUnfolding expr'
756 returnM (info `setUnfoldingInfoLazily` unfold_info)
760 tcWorkerInfo ty info wkr arity
761 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
763 -- We return without testing maybe_wkr_id, but as soon as info is
764 -- looked at we will test it. That's ok, because its outside the
765 -- knot; and there seems no big reason to further defer the
766 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
767 -- over the unfolding until it's actually used does seem worth while.)
768 ; us <- newUniqueSupply
770 ; returnM (case mb_wkr_id of
772 Just wkr_id -> add_wkr_info us wkr_id info) }
774 doc = text "Worker for" <+> ppr wkr
775 add_wkr_info us wkr_id info
776 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
777 `setWorkerInfo` HasWorker wkr_id arity
779 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
781 -- We are relying here on strictness info always appearing
782 -- before worker info, fingers crossed ....
783 strict_sig = case newStrictnessInfo info of
785 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
788 For unfoldings we try to do the job lazily, so that we never type check
789 an unfolding that isn't going to be looked at.
792 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
795 tcIfaceExpr expr `thenM` \ core_expr' ->
797 -- Check for type consistency in the unfolding
798 ifOptM Opt_DoCoreLinting (
799 get_in_scope_ids `thenM` \ in_scope ->
800 case lintUnfolding noSrcLoc in_scope core_expr' of
801 Nothing -> returnM ()
802 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
807 doc = text "Unfolding of" <+> ppr name
808 get_in_scope_ids -- Urgh; but just for linting
810 do { env <- getGblEnv
811 ; case if_rec_types env of {
812 Nothing -> return [] ;
813 Just (_, get_env) -> do
814 { type_env <- get_env
815 ; return (typeEnvIds type_env) }}}
820 %************************************************************************
822 Getting from Names to TyThings
824 %************************************************************************
827 tcIfaceGlobal :: Name -> IfL TyThing
829 | Just thing <- wiredInNameTyThing_maybe name
830 -- Wired-in things include TyCons, DataCons, and Ids
831 = do { loadWiredInHomeIface name; return thing }
832 -- Even though we are in an interface file, we want to make
833 -- sure its instances are loaded (imagine f :: Double -> Double)
834 -- and its RULES are loaded too
836 = do { (eps,hpt) <- getEpsAndHpt
838 ; case lookupType dflags hpt (eps_PTE eps) name of {
839 Just thing -> return thing ;
843 ; case if_rec_types env of {
844 Just (mod, get_type_env)
845 | nameIsLocalOrFrom mod name
846 -> do -- It's defined in the module being compiled
847 { type_env <- setLclEnv () get_type_env -- yuk
848 ; case lookupNameEnv type_env name of
849 Just thing -> return thing
850 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
851 (ppr name $$ ppr type_env) }
855 { mb_thing <- importDecl name -- It's imported; go get it
857 Failed err -> failIfM err
858 Succeeded thing -> return thing
861 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
862 tcIfaceTyCon IfaceIntTc = tcWiredInTyCon intTyCon
863 tcIfaceTyCon IfaceBoolTc = tcWiredInTyCon boolTyCon
864 tcIfaceTyCon IfaceCharTc = tcWiredInTyCon charTyCon
865 tcIfaceTyCon IfaceListTc = tcWiredInTyCon listTyCon
866 tcIfaceTyCon IfacePArrTc = tcWiredInTyCon parrTyCon
867 tcIfaceTyCon (IfaceTupTc bx ar) = tcWiredInTyCon (tupleTyCon bx ar)
868 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
869 ; thing <- tcIfaceGlobal name
870 ; return (check_tc (tyThingTyCon thing)) }
873 check_tc tc = case toIfaceTyCon (error "urk") tc of
875 other -> pprTrace "check_tc" (ppr tc) tc
879 -- we should be okay just returning Kind constructors without extra loading
880 tcIfaceTyCon IfaceLiftedTypeKindTc = return liftedTypeKindTyCon
881 tcIfaceTyCon IfaceOpenTypeKindTc = return openTypeKindTyCon
882 tcIfaceTyCon IfaceUnliftedTypeKindTc = return unliftedTypeKindTyCon
883 tcIfaceTyCon IfaceArgTypeKindTc = return argTypeKindTyCon
884 tcIfaceTyCon IfaceUbxTupleKindTc = return ubxTupleKindTyCon
886 -- Even though we are in an interface file, we want to make
887 -- sure the instances and RULES of this tycon are loaded
888 -- Imagine: f :: Double -> Double
889 tcWiredInTyCon :: TyCon -> IfL TyCon
890 tcWiredInTyCon tc = do { loadWiredInHomeIface (tyConName tc)
893 tcIfaceClass :: IfaceExtName -> IfL Class
894 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
895 ; thing <- tcIfaceGlobal name
896 ; return (tyThingClass thing) }
898 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
899 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
900 ; thing <- tcIfaceGlobal name
902 ADataCon dc -> return dc
903 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
905 tcIfaceExtId :: IfaceExtName -> IfL Id
906 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
907 ; thing <- tcIfaceGlobal name
910 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
913 %************************************************************************
917 %************************************************************************
920 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
921 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
922 = bindIfaceId bndr thing_inside
923 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
924 = bindIfaceTyVar bndr thing_inside
926 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
927 bindIfaceBndrs [] thing_inside = thing_inside []
928 bindIfaceBndrs (b:bs) thing_inside
929 = bindIfaceBndr b $ \ b' ->
930 bindIfaceBndrs bs $ \ bs' ->
931 thing_inside (b':bs')
933 -----------------------
934 bindIfaceId :: IfaceIdBndr -> (Id -> IfL a) -> IfL a
935 bindIfaceId (occ, ty) thing_inside
936 = do { name <- newIfaceName (mkVarOccFS occ)
937 ; ty' <- tcIfaceType ty
938 ; let { id = mkLocalId name ty' }
939 ; extendIfaceIdEnv [id] (thing_inside id) }
941 bindIfaceIds :: [IfaceIdBndr] -> ([Id] -> IfL a) -> IfL a
942 bindIfaceIds bndrs thing_inside
943 = do { names <- newIfaceNames (map mkVarOccFS occs)
944 ; tys' <- mappM tcIfaceType tys
945 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
946 ; extendIfaceIdEnv ids (thing_inside ids) }
948 (occs,tys) = unzip bndrs
951 -----------------------
952 newExtCoreBndr :: IfaceIdBndr -> IfL Id
953 newExtCoreBndr (var, ty)
954 = do { mod <- getIfModule
955 ; name <- newGlobalBinder mod (mkVarOccFS var) Nothing noSrcLoc
956 ; ty' <- tcIfaceType ty
957 ; return (mkLocalId name ty') }
959 -----------------------
960 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
961 bindIfaceTyVar (occ,kind) thing_inside
962 = do { name <- newIfaceName (mkTyVarOcc occ)
963 ; tyvar <- mk_iface_tyvar name kind
964 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
966 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
967 bindIfaceTyVars bndrs thing_inside
968 = do { names <- newIfaceNames (map mkTyVarOcc occs)
969 ; tyvars <- zipWithM mk_iface_tyvar names kinds
970 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
972 (occs,kinds) = unzip bndrs
974 mk_iface_tyvar :: Name -> IfaceKind -> IfL TyVar
975 mk_iface_tyvar name ifKind = do { kind <- tcIfaceType ifKind
976 ; return (mkTyVar name kind)