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, loadHomeInterface, loadDecls, findAndReadIface )
17 import IfaceEnv ( lookupIfaceTop, lookupIfaceExt, newGlobalBinder,
18 extendIfaceIdEnv, extendIfaceTyVarEnv, newIPName,
19 tcIfaceTyVar, tcIfaceLclId, lookupIfaceTc,
20 newIfaceName, newIfaceNames, ifaceExportNames )
21 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass,
22 mkAbstractTyConRhs, mkDataTyConRhs, mkNewTyConRhs )
24 import TcType ( hoistForAllTys ) -- TEMPORARY HACK
25 import Type ( liftedTypeKind, splitTyConApp, mkSynTy, mkTyConApp,
26 mkTyVarTys, ThetaType,
27 mkGenTyConApp ) -- Don't remove this... see mkIfTcApp
28 import TypeRep ( Type(..), PredType(..) )
29 import TyCon ( TyCon, tyConName, isSynTyCon )
30 import HscTypes ( ExternalPackageState(..),
31 TyThing(..), tyThingClass, tyThingTyCon,
32 ModIface(..), ModDetails(..), HomeModInfo(..),
33 emptyModDetails, lookupTypeEnv, lookupType, typeEnvIds )
34 import InstEnv ( Instance(..), mkImportedInstance )
36 import CoreUtils ( exprType )
38 import CoreLint ( lintUnfolding )
39 import WorkWrap ( mkWrapper )
40 import Id ( Id, mkVanillaGlobal, mkLocalId )
41 import MkId ( mkFCallId )
42 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
43 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
44 setArityInfo, setInlinePragInfo, setCafInfo,
45 vanillaIdInfo, newStrictnessInfo )
46 import Class ( Class )
47 import TyCon ( tyConDataCons, isTupleTyCon, mkForeignTyCon )
48 import DataCon ( DataCon, dataConWorkId, dataConTyVars, dataConArgTys, isVanillaDataCon )
49 import TysWiredIn ( tupleCon, tupleTyCon, listTyCon, intTyCon, boolTyCon, charTyCon, parrTyCon )
50 import Var ( TyVar, mkTyVar, tyVarKind )
51 import Name ( Name, nameModule, nameIsLocalOrFrom, isWiredInName,
52 wiredInNameTyThing_maybe, nameParent )
54 import OccName ( OccName )
55 import Module ( Module, lookupModuleEnv )
56 import UniqSupply ( initUs_ )
58 import ErrUtils ( Message )
59 import Maybes ( MaybeErr(..) )
60 import SrcLoc ( noSrcLoc )
61 import Util ( zipWithEqual, dropList, equalLength )
62 import DynFlags ( DynFlag(..), isOneShot )
71 An IfaceDecl is populated with RdrNames, and these are not renamed to
72 Names before typechecking, because there should be no scope errors etc.
74 -- For (b) consider: f = $(...h....)
75 -- where h is imported, and calls f via an hi-boot file.
76 -- This is bad! But it is not seen as a staging error, because h
77 -- is indeed imported. We don't want the type-checker to black-hole
78 -- when simplifying and compiling the splice!
80 -- Simple solution: discard any unfolding that mentions a variable
81 -- bound in this module (and hence not yet processed).
82 -- The discarding happens when forkM finds a type error.
84 %************************************************************************
86 %* tcImportDecl is the key function for "faulting in" *
89 %************************************************************************
91 The main idea is this. We are chugging along type-checking source code, and
92 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
93 it in the EPS type envt. So it
95 2 gets the decl for GHC.Base.map
96 3 typechecks it via tcIfaceDecl
97 4 and adds it to the type env in the EPS
99 Note that DURING STEP 4, we may find that map's type mentions a type
100 constructor that also
102 Notice that for imported things we read the current version from the EPS
103 mutable variable. This is important in situations like
105 where the code that e1 expands to might import some defns that
106 also turn out to be needed by the code that e2 expands to.
109 tcImportDecl :: Name -> TcM TyThing
110 -- Entry point for *source-code* uses of importDecl
112 | Just thing <- wiredInNameTyThing_maybe name
113 = do { checkWiredInName name; return thing }
115 = do { traceIf (text "tcLookupGlobal" <+> ppr name)
116 ; mb_thing <- initIfaceTcRn (importDecl name)
118 Succeeded thing -> return thing
119 Failed err -> failWithTc err }
121 checkWiredInTyCon :: TyCon -> TcM ()
122 -- Ensure its instances are loaded
123 -- It might not be a wired-in tycon (see the calls in TcUnify)
125 | not (isWiredInName tc_name) = return ()
126 | otherwise = checkWiredInName tc_name
128 tc_name = tyConName tc
130 checkWiredInName :: Name -> TcM ()
131 -- We "check" a wired-in name solely to check that its
132 -- interface file is loaded, so that we're sure that we see
133 -- its instance declarations and rules
134 checkWiredInName name
135 = ASSERT( isWiredInName name )
136 do { mod <- getModule
137 ; if nameIsLocalOrFrom mod name then
138 -- Don't look for (non-existent) Float.hi when
139 -- compiling Float.lhs, which mentions Float of course
141 else -- A bit yukky to call initIfaceTcRn here
142 do { loadHomeInterface doc name; return () }
145 doc = ptext SLIT("Need home interface for wired-in thing") <+> ppr name
147 importDecl :: Name -> IfM lcl (MaybeErr Message TyThing)
148 -- Get the TyThing for this Name from an interface file
149 -- It's not a wired-in thing -- the caller caught that
151 = ASSERT( not (isWiredInName name) )
154 -- Load the interface, which should populate the PTE
155 ; mb_iface <- loadInterface nd_doc (nameModule name) ImportBySystem
157 Failed err_msg -> return (Failed err_msg) ;
158 Succeeded iface -> do
160 -- Now look it up again; this time we should find it
162 ; case lookupTypeEnv (eps_PTE eps) name of
163 Just thing -> return (Succeeded thing)
164 Nothing -> return (Failed not_found_msg)
167 nd_doc = ptext SLIT("Need decl for") <+> ppr name
168 not_found_msg = hang (ptext SLIT("Can't find interface-file declaration for") <+> ppr (nameParent name))
169 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
170 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
173 %************************************************************************
175 Type-checking a complete interface
177 %************************************************************************
179 Suppose we discover we don't need to recompile. Then we must type
180 check the old interface file. This is a bit different to the
181 incremental type checking we do as we suck in interface files. Instead
182 we do things similarly as when we are typechecking source decls: we
183 bring into scope the type envt for the interface all at once, using a
184 knot. Remember, the decls aren't necessarily in dependency order --
185 and even if they were, the type decls might be mutually recursive.
188 typecheckIface :: ModIface -- Get the decls from here
189 -> TcRnIf gbl lcl ModDetails
191 = initIfaceTc iface $ \ tc_env_var -> do
192 -- The tc_env_var is freshly allocated, private to
193 -- type-checking this particular interface
194 { -- Get the right set of decls and rules. If we are compiling without -O
195 -- we discard pragmas before typechecking, so that we don't "see"
196 -- information that we shouldn't. From a versioning point of view
197 -- It's not actually *wrong* to do so, but in fact GHCi is unable
198 -- to handle unboxed tuples, so it must not see unfoldings.
199 ignore_prags <- doptM Opt_IgnoreInterfacePragmas
201 -- Load & typecheck the decls
202 ; decl_things <- loadDecls ignore_prags (mi_decls iface)
204 ; let type_env = mkNameEnv decl_things
205 ; writeMutVar tc_env_var type_env
207 -- Now do those rules and instances
208 ; let { rules | ignore_prags = []
209 | otherwise = mi_rules iface
210 ; dfuns = mi_insts iface
212 ; dfuns <- mapM tcIfaceInst dfuns
213 ; rules <- mapM tcIfaceRule rules
216 ; exports <- ifaceExportNames (mi_exports iface)
219 ; return (ModDetails { md_types = type_env,
222 md_exports = exports })
227 %************************************************************************
229 Type and class declarations
231 %************************************************************************
234 tcHiBootIface :: Module -> TcRn ModDetails
235 -- Load the hi-boot iface for the module being compiled,
236 -- if it indeed exists in the transitive closure of imports
237 -- Return the ModDetails, empty if no hi-boot iface
239 = do { traceIf (text "loadHiBootInterface" <+> ppr mod)
241 ; mode <- getGhciMode
242 ; if not (isOneShot mode)
243 -- In --make and interactive mode, if this module has an hs-boot file
244 -- we'll have compiled it already, and it'll be in the HPT
245 then do { hpt <- getHpt
246 ; case lookupModuleEnv hpt mod of
247 Just info -> return (hm_details info)
248 Nothing -> return emptyModDetails }
251 -- OK, so we're in one-shot mode.
252 -- In that case, we're read all the direct imports by now,
253 -- so eps_is_boot will record if any of our imports mention us by
254 -- way of hi-boot file
256 ; case lookupModuleEnv (eps_is_boot eps) mod of {
257 Nothing -> return emptyModDetails ; -- The typical case
259 Just (_, False) -> failWithTc moduleLoop ;
260 -- Someone below us imported us!
261 -- This is a loop with no hi-boot in the way
263 Just (mod, True) -> -- There's a hi-boot interface below us
265 do { read_result <- findAndReadIface
266 True -- Explicit import?
270 ; case read_result of
271 Failed err -> failWithTc (elaborate err)
272 Succeeded (iface, _path) -> typecheckIface iface
275 need = ptext SLIT("Need the hi-boot interface for") <+> ppr mod
276 <+> ptext SLIT("to compare against the Real Thing")
278 moduleLoop = ptext SLIT("Circular imports: module") <+> quotes (ppr mod)
279 <+> ptext SLIT("depends on itself")
281 elaborate err = hang (ptext SLIT("Could not find hi-boot interface for") <+>
282 quotes (ppr mod) <> colon) 4 err
286 %************************************************************************
288 Type and class declarations
290 %************************************************************************
292 When typechecking a data type decl, we *lazily* (via forkM) typecheck
293 the constructor argument types. This is in the hope that we may never
294 poke on those argument types, and hence may never need to load the
295 interface files for types mentioned in the arg types.
298 data Foo.S = MkS Baz.T
299 Mabye we can get away without even loading the interface for Baz!
301 This is not just a performance thing. Suppose we have
302 data Foo.S = MkS Baz.T
303 data Baz.T = MkT Foo.S
304 (in different interface files, of course).
305 Now, first we load and typecheck Foo.S, and add it to the type envt.
306 If we do explore MkS's argument, we'll load and typecheck Baz.T.
307 If we explore MkT's argument we'll find Foo.S already in the envt.
309 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
310 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
311 which isn't done yet.
313 All very cunning. However, there is a rather subtle gotcha which bit
314 me when developing this stuff. When we typecheck the decl for S, we
315 extend the type envt with S, MkS, and all its implicit Ids. Suppose
316 (a bug, but it happened) that the list of implicit Ids depended in
317 turn on the constructor arg types. Then the following sequence of
319 * we build a thunk <t> for the constructor arg tys
320 * we build a thunk for the extended type environment (depends on <t>)
321 * we write the extended type envt into the global EPS mutvar
323 Now we look something up in the type envt
325 * which reads the global type envt out of the global EPS mutvar
326 * but that depends in turn on <t>
328 It's subtle, because, it'd work fine if we typechecked the constructor args
329 eagerly -- they don't need the extended type envt. They just get the extended
330 type envt by accident, because they look at it later.
332 What this means is that the implicitTyThings MUST NOT DEPEND on any of
337 tcIfaceDecl :: IfaceDecl -> IfL TyThing
339 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
340 = do { name <- lookupIfaceTop occ_name
341 ; ty <- tcIfaceType iface_type
342 ; info <- tcIdInfo name ty info
343 ; return (AnId (mkVanillaGlobal name ty info)) }
345 tcIfaceDecl (IfaceData {ifName = occ_name,
349 ifVrcs = arg_vrcs, ifRec = is_rec,
350 ifGeneric = want_generic })
351 = do { tc_name <- lookupIfaceTop occ_name
352 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
354 { tycon <- fixM ( \ tycon -> do
355 { stupid_theta <- tcIfaceCtxt ctxt
356 ; cons <- tcIfaceDataCons tycon tyvars rdr_cons
357 ; buildAlgTyCon tc_name tyvars stupid_theta
358 cons arg_vrcs is_rec want_generic
360 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
361 ; return (ATyCon tycon)
364 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
365 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
366 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
367 { tc_name <- lookupIfaceTop occ_name
368 ; rhs_ty <- tcIfaceType rdr_rhs_ty
369 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
372 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
373 ifFDs = rdr_fds, ifSigs = rdr_sigs,
374 ifVrcs = tc_vrcs, ifRec = tc_isrec })
375 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
376 { cls_name <- lookupIfaceTop occ_name
377 ; ctxt <- tcIfaceCtxt rdr_ctxt
378 ; sigs <- mappM tc_sig rdr_sigs
379 ; fds <- mappM tc_fd rdr_fds
380 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
381 ; return (AClass cls) }
383 tc_sig (IfaceClassOp occ dm rdr_ty)
384 = do { op_name <- lookupIfaceTop occ
385 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
386 -- Must be done lazily for just the same reason as the
387 -- context of a data decl: the type sig might mention the
388 -- class being defined
389 ; return (op_name, dm, op_ty) }
391 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
393 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
394 ; tvs2' <- mappM tcIfaceTyVar tvs2
395 ; return (tvs1', tvs2') }
397 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
398 = do { name <- lookupIfaceTop rdr_name
399 ; return (ATyCon (mkForeignTyCon name ext_name
400 liftedTypeKind 0 [])) }
402 tcIfaceDataCons tycon tc_tyvars if_cons
404 IfAbstractTyCon -> return mkAbstractTyConRhs
405 IfDataTyCon cons -> do { data_cons <- mappM tc_con_decl cons
406 ; return (mkDataTyConRhs data_cons) }
407 IfNewTyCon con -> do { data_con <- tc_con_decl con
408 ; return (mkNewTyConRhs tycon data_con) }
410 tc_con_decl (IfVanillaCon { ifConOcc = occ, ifConInfix = is_infix, ifConArgTys = args,
411 ifConStricts = stricts, ifConFields = field_lbls})
412 = do { name <- lookupIfaceTop occ
413 -- Read the argument types, but lazily to avoid faulting in
414 -- the component types unless they are really needed
415 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
416 ; lbl_names <- mappM lookupIfaceTop field_lbls
417 ; buildDataCon name is_infix True {- Vanilla -}
419 tc_tyvars [] arg_tys tycon
420 (mkTyVarTys tc_tyvars) -- Vanilla => we know result tys
423 tc_con_decl (IfGadtCon { ifConTyVars = con_tvs,
424 ifConOcc = occ, ifConCtxt = ctxt,
425 ifConArgTys = args, ifConResTys = ress,
426 ifConStricts = stricts})
427 = bindIfaceTyVars con_tvs $ \ con_tyvars -> do
428 { name <- lookupIfaceTop occ
429 ; theta <- tcIfaceCtxt ctxt -- Laziness seems not worth the bother here
430 -- At one stage I thought that this context checking *had*
431 -- to be lazy, because of possible mutual recursion between the
432 -- type and the classe:
434 -- class Real a where { toRat :: a -> Ratio Integer }
435 -- data (Real a) => Ratio a = ...
436 -- But now I think that the laziness in checking class ops breaks
437 -- the loop, so no laziness needed
439 -- Read the argument types, but lazily to avoid faulting in
440 -- the component types unless they are really needed
441 ; arg_tys <- forkM (mk_doc name) (mappM tcIfaceType args)
442 ; res_tys <- forkM (mk_doc name) (mappM tcIfaceType ress)
444 ; buildDataCon name False {- Not infix -} False {- Not vanilla -}
445 stricts [{- No fields -}]
447 arg_tys tycon res_tys
449 mk_doc con_name = ptext SLIT("Constructor") <+> ppr con_name
453 %************************************************************************
457 %************************************************************************
460 tcIfaceInst :: IfaceInst -> IfL Instance
461 tcIfaceInst (IfaceInst { ifDFun = dfun_occ, ifOFlag = oflag,
462 ifInstCls = cls, ifInstTys = mb_tcs,
464 = do { dfun <- forkM (ptext SLIT("Dict fun") <+> ppr dfun_occ) $
465 tcIfaceExtId (LocalTop dfun_occ)
466 ; cls' <- lookupIfaceExt cls
467 ; mb_tcs' <- mapM do_tc mb_tcs
468 ; return (mkImportedInstance cls' mb_tcs' orph dfun oflag) }
470 do_tc Nothing = return Nothing
471 do_tc (Just tc) = do { tc' <- lookupIfaceTc tc; return (Just tc') }
475 %************************************************************************
479 %************************************************************************
481 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
482 are in the type environment. However, remember that typechecking a Rule may
483 (as a side effect) augment the type envt, and so we may need to iterate the process.
486 tcIfaceRule :: IfaceRule -> IfL CoreRule
487 tcIfaceRule (IfaceRule {ifRuleName = name, ifActivation = act, ifRuleBndrs = bndrs,
488 ifRuleHead = fn, ifRuleArgs = args, ifRuleRhs = rhs,
490 = do { fn' <- lookupIfaceExt fn
491 ; ~(bndrs', args', rhs') <-
492 -- Typecheck the payload lazily, in the hope it'll never be looked at
493 forkM (ptext SLIT("Rule") <+> ftext name) $
494 bindIfaceBndrs bndrs $ \ bndrs' ->
495 do { args' <- mappM tcIfaceExpr args
496 ; rhs' <- tcIfaceExpr rhs
497 ; return (bndrs', args', rhs') }
498 ; mb_tcs <- mapM ifTopFreeName args
499 ; returnM (Rule { ru_name = name, ru_fn = fn', ru_act = act,
500 ru_bndrs = bndrs', ru_args = args',
501 ru_rhs = rhs', ru_orph = orph,
503 ru_local = isLocalIfaceExtName fn }) }
505 -- This function *must* mirror exactly what Rules.topFreeName does
506 -- We could have stored the ru_rough field in the iface file
507 -- but that would be redundant, I think.
508 -- The only wrinkle is that we must not be deceived by
509 -- type syononyms at the top of a type arg. Since
510 -- we can't tell at this point, we are careful not
511 -- to write them out in coreRuleToIfaceRule
512 ifTopFreeName :: IfaceExpr -> IfL (Maybe Name)
513 ifTopFreeName (IfaceType (IfaceTyConApp tc _ ))
514 = do { n <- lookupIfaceTc tc
516 ifTopFreeName (IfaceApp f a) = ifTopFreeName f
517 ifTopFreeName (IfaceExt ext) = do { n <- lookupIfaceExt ext
519 ifTopFreeName other = return Nothing
523 %************************************************************************
527 %************************************************************************
530 tcIfaceType :: IfaceType -> IfL Type
531 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
532 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
533 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
534 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkIfTcApp tc' ts') }
535 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
536 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
538 tcIfaceTypes tys = mapM tcIfaceType tys
540 mkIfTcApp :: TyCon -> [Type] -> Type
541 -- In interface files we retain type synonyms (for brevity and better error
542 -- messages), but type synonyms can expand into non-hoisted types (ones with
543 -- foralls to the right of an arrow), so we must be careful to hoist them here.
544 -- This hack should go away when we get rid of hoisting.
545 -- Then we should go back to mkGenTyConApp or something like it
547 | isSynTyCon tc = hoistForAllTys (mkSynTy tc tys)
548 | otherwise = mkTyConApp tc tys
550 -----------------------------------------
551 tcIfacePredType :: IfacePredType -> IfL PredType
552 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
553 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
555 -----------------------------------------
556 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
557 tcIfaceCtxt sts = mappM tcIfacePredType sts
561 %************************************************************************
565 %************************************************************************
568 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
569 tcIfaceExpr (IfaceType ty)
570 = tcIfaceType ty `thenM` \ ty' ->
573 tcIfaceExpr (IfaceLcl name)
574 = tcIfaceLclId name `thenM` \ id ->
577 tcIfaceExpr (IfaceExt gbl)
578 = tcIfaceExtId gbl `thenM` \ id ->
581 tcIfaceExpr (IfaceLit lit)
584 tcIfaceExpr (IfaceFCall cc ty)
585 = tcIfaceType ty `thenM` \ ty' ->
586 newUnique `thenM` \ u ->
587 returnM (Var (mkFCallId u cc ty'))
589 tcIfaceExpr (IfaceTuple boxity args)
590 = mappM tcIfaceExpr args `thenM` \ args' ->
592 -- Put the missing type arguments back in
593 con_args = map (Type . exprType) args' ++ args'
595 returnM (mkApps (Var con_id) con_args)
598 con_id = dataConWorkId (tupleCon boxity arity)
601 tcIfaceExpr (IfaceLam bndr body)
602 = bindIfaceBndr bndr $ \ bndr' ->
603 tcIfaceExpr body `thenM` \ body' ->
604 returnM (Lam bndr' body')
606 tcIfaceExpr (IfaceApp fun arg)
607 = tcIfaceExpr fun `thenM` \ fun' ->
608 tcIfaceExpr arg `thenM` \ arg' ->
609 returnM (App fun' arg')
611 tcIfaceExpr (IfaceCase scrut case_bndr ty alts)
612 = tcIfaceExpr scrut `thenM` \ scrut' ->
613 newIfaceName case_bndr `thenM` \ case_bndr_name ->
615 scrut_ty = exprType scrut'
616 case_bndr' = mkLocalId case_bndr_name scrut_ty
617 tc_app = splitTyConApp scrut_ty
618 -- NB: Won't always succeed (polymoprhic case)
619 -- but won't be demanded in those cases
620 -- NB: not tcSplitTyConApp; we are looking at Core here
621 -- look through non-rec newtypes to find the tycon that
622 -- corresponds to the datacon in this case alternative
624 extendIfaceIdEnv [case_bndr'] $
625 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
626 tcIfaceType ty `thenM` \ ty' ->
627 returnM (Case scrut' case_bndr' ty' alts')
629 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
630 = tcIfaceExpr rhs `thenM` \ rhs' ->
631 bindIfaceId bndr $ \ bndr' ->
632 tcIfaceExpr body `thenM` \ body' ->
633 returnM (Let (NonRec bndr' rhs') body')
635 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
636 = bindIfaceIds bndrs $ \ bndrs' ->
637 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
638 tcIfaceExpr body `thenM` \ body' ->
639 returnM (Let (Rec (bndrs' `zip` rhss')) body')
641 (bndrs, rhss) = unzip pairs
643 tcIfaceExpr (IfaceNote note expr)
644 = tcIfaceExpr expr `thenM` \ expr' ->
646 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
647 returnM (Note (Coerce to_ty'
648 (exprType expr')) expr')
649 IfaceInlineCall -> returnM (Note InlineCall expr')
650 IfaceInlineMe -> returnM (Note InlineMe expr')
651 IfaceSCC cc -> returnM (Note (SCC cc) expr')
652 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
654 -------------------------
655 tcIfaceAlt _ (IfaceDefault, names, rhs)
656 = ASSERT( null names )
657 tcIfaceExpr rhs `thenM` \ rhs' ->
658 returnM (DEFAULT, [], rhs')
660 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
661 = ASSERT( null names )
662 tcIfaceExpr rhs `thenM` \ rhs' ->
663 returnM (LitAlt lit, [], rhs')
665 -- A case alternative is made quite a bit more complicated
666 -- by the fact that we omit type annotations because we can
667 -- work them out. True enough, but its not that easy!
668 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
669 = do { let tycon_mod = nameModule (tyConName tycon)
670 ; con <- tcIfaceDataCon (ExtPkg tycon_mod data_occ)
671 ; ASSERT2( con `elem` tyConDataCons tycon,
672 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) )
674 if isVanillaDataCon con then
675 tcVanillaAlt con inst_tys arg_occs rhs
678 arg_names <- newIfaceNames arg_occs
679 ; let tyvars = [ mkTyVar name (tyVarKind tv)
680 | (name,tv) <- arg_names `zip` dataConTyVars con]
681 arg_tys = dataConArgTys con (mkTyVarTys tyvars)
682 id_names = dropList tyvars arg_names
683 arg_ids = ASSERT2( equalLength id_names arg_tys,
684 ppr (con, arg_names, rhs) $$ ppr tyvars $$ ppr arg_tys )
685 zipWith mkLocalId id_names arg_tys
687 ; rhs' <- extendIfaceTyVarEnv tyvars $
688 extendIfaceIdEnv arg_ids $
690 ; return (DataAlt con, tyvars ++ arg_ids, rhs') }}
692 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
693 = ASSERT( isTupleTyCon tycon )
694 do { let [data_con] = tyConDataCons tycon
695 ; tcVanillaAlt data_con inst_tys arg_occs rhs }
697 tcVanillaAlt data_con inst_tys arg_occs rhs
698 = do { arg_names <- newIfaceNames arg_occs
699 ; let arg_tys = dataConArgTys data_con inst_tys
700 ; let arg_ids = ASSERT2( equalLength arg_names arg_tys,
701 ppr data_con <+> ppr inst_tys <+> ppr arg_occs $$ ppr rhs )
702 zipWith mkLocalId arg_names arg_tys
703 ; rhs' <- extendIfaceIdEnv arg_ids (tcIfaceExpr rhs)
704 ; returnM (DataAlt data_con, arg_ids, rhs') }
709 tcExtCoreBindings :: [IfaceBinding] -> IfL [CoreBind] -- Used for external core
710 tcExtCoreBindings [] = return []
711 tcExtCoreBindings (b:bs) = do_one b (tcExtCoreBindings bs)
713 do_one :: IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
714 do_one (IfaceNonRec bndr rhs) thing_inside
715 = do { rhs' <- tcIfaceExpr rhs
716 ; bndr' <- newExtCoreBndr bndr
717 ; extendIfaceIdEnv [bndr'] $ do
718 { core_binds <- thing_inside
719 ; return (NonRec bndr' rhs' : core_binds) }}
721 do_one (IfaceRec pairs) thing_inside
722 = do { bndrs' <- mappM newExtCoreBndr bndrs
723 ; extendIfaceIdEnv bndrs' $ do
724 { rhss' <- mappM tcIfaceExpr rhss
725 ; core_binds <- thing_inside
726 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
728 (bndrs,rhss) = unzip pairs
732 %************************************************************************
736 %************************************************************************
739 tcIdInfo :: Name -> Type -> IfaceIdInfo -> IfL IdInfo
740 tcIdInfo name ty NoInfo = return vanillaIdInfo
741 tcIdInfo name ty (HasInfo info) = foldlM tcPrag init_info info
743 -- Set the CgInfo to something sensible but uninformative before
744 -- we start; default assumption is that it has CAFs
745 init_info = vanillaIdInfo
747 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
748 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
749 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
751 -- The next two are lazy, so they don't transitively suck stuff in
752 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
753 tcPrag info (HsUnfold inline_prag expr)
754 = tcPragExpr name expr `thenM` \ maybe_expr' ->
756 -- maybe_expr' doesn't get looked at if the unfolding
757 -- is never inspected; so the typecheck doesn't even happen
758 unfold_info = case maybe_expr' of
759 Nothing -> noUnfolding
760 Just expr' -> mkTopUnfolding expr'
762 returnM (info `setUnfoldingInfoLazily` unfold_info
763 `setInlinePragInfo` inline_prag)
767 tcWorkerInfo ty info wkr arity
768 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId wkr)
770 -- We return without testing maybe_wkr_id, but as soon as info is
771 -- looked at we will test it. That's ok, because its outside the
772 -- knot; and there seems no big reason to further defer the
773 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
774 -- over the unfolding until it's actually used does seem worth while.)
775 ; us <- newUniqueSupply
777 ; returnM (case mb_wkr_id of
779 Just wkr_id -> add_wkr_info us wkr_id info) }
781 doc = text "Worker for" <+> ppr wkr
782 add_wkr_info us wkr_id info
783 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
784 `setWorkerInfo` HasWorker wkr_id arity
786 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
788 -- We are relying here on strictness info always appearing
789 -- before worker info, fingers crossed ....
790 strict_sig = case newStrictnessInfo info of
792 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr)
795 For unfoldings we try to do the job lazily, so that we never type check
796 an unfolding that isn't going to be looked at.
799 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
802 tcIfaceExpr expr `thenM` \ core_expr' ->
804 -- Check for type consistency in the unfolding
805 ifOptM Opt_DoCoreLinting (
806 get_in_scope_ids `thenM` \ in_scope ->
807 case lintUnfolding noSrcLoc in_scope core_expr' of
808 Nothing -> returnM ()
809 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
814 doc = text "Unfolding of" <+> ppr name
815 get_in_scope_ids -- Urgh; but just for linting
817 do { env <- getGblEnv
818 ; case if_rec_types env of {
819 Nothing -> return [] ;
820 Just (_, get_env) -> do
821 { type_env <- get_env
822 ; return (typeEnvIds type_env) }}}
827 %************************************************************************
829 Getting from Names to TyThings
831 %************************************************************************
834 tcIfaceGlobal :: Name -> IfL TyThing
836 | Just thing <- wiredInNameTyThing_maybe name
839 = do { (eps,hpt) <- getEpsAndHpt
840 ; case lookupType hpt (eps_PTE eps) name of {
841 Just thing -> return thing ;
845 ; case if_rec_types env of {
846 Just (mod, get_type_env)
847 | nameIsLocalOrFrom mod name
848 -> do -- It's defined in the module being compiled
849 { type_env <- setLclEnv () get_type_env -- yuk
850 ; case lookupNameEnv type_env name of
851 Just thing -> return thing
852 Nothing -> pprPanic "tcIfaceGlobal (local): not found:"
853 (ppr name $$ ppr type_env) }
857 { mb_thing <- importDecl name -- It's imported; go get it
859 Failed err -> failIfM err
860 Succeeded thing -> return thing
863 tcIfaceTyCon :: IfaceTyCon -> IfL TyCon
864 tcIfaceTyCon IfaceIntTc = return intTyCon
865 tcIfaceTyCon IfaceBoolTc = return boolTyCon
866 tcIfaceTyCon IfaceCharTc = return charTyCon
867 tcIfaceTyCon IfaceListTc = return listTyCon
868 tcIfaceTyCon IfacePArrTc = return parrTyCon
869 tcIfaceTyCon (IfaceTupTc bx ar) = return (tupleTyCon bx ar)
870 tcIfaceTyCon (IfaceTc ext_nm) = do { name <- lookupIfaceExt ext_nm
871 ; thing <- tcIfaceGlobal name
872 ; return (tyThingTyCon thing) }
874 tcIfaceClass :: IfaceExtName -> IfL Class
875 tcIfaceClass rdr_name = do { name <- lookupIfaceExt rdr_name
876 ; thing <- tcIfaceGlobal name
877 ; return (tyThingClass thing) }
879 tcIfaceDataCon :: IfaceExtName -> IfL DataCon
880 tcIfaceDataCon gbl = do { name <- lookupIfaceExt gbl
881 ; thing <- tcIfaceGlobal name
883 ADataCon dc -> return dc
884 other -> pprPanic "tcIfaceExtDC" (ppr gbl $$ ppr name$$ ppr thing) }
886 tcIfaceExtId :: IfaceExtName -> IfL Id
887 tcIfaceExtId gbl = do { name <- lookupIfaceExt gbl
888 ; thing <- tcIfaceGlobal name
891 other -> pprPanic "tcIfaceExtId" (ppr gbl $$ ppr name$$ ppr thing) }
894 %************************************************************************
898 %************************************************************************
901 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
902 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
903 = bindIfaceId bndr thing_inside
904 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
905 = bindIfaceTyVar bndr thing_inside
907 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
908 bindIfaceBndrs [] thing_inside = thing_inside []
909 bindIfaceBndrs (b:bs) thing_inside
910 = bindIfaceBndr b $ \ b' ->
911 bindIfaceBndrs bs $ \ bs' ->
912 thing_inside (b':bs')
914 -----------------------
915 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
916 bindIfaceId (occ, ty) thing_inside
917 = do { name <- newIfaceName occ
918 ; ty' <- tcIfaceType ty
919 ; let { id = mkLocalId name ty' }
920 ; extendIfaceIdEnv [id] (thing_inside id) }
922 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
923 bindIfaceIds bndrs thing_inside
924 = do { names <- newIfaceNames occs
925 ; tys' <- mappM tcIfaceType tys
926 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
927 ; extendIfaceIdEnv ids (thing_inside ids) }
929 (occs,tys) = unzip bndrs
932 -----------------------
933 newExtCoreBndr :: (OccName, IfaceType) -> IfL Id
934 newExtCoreBndr (occ, ty)
935 = do { mod <- getIfModule
936 ; name <- newGlobalBinder mod occ Nothing noSrcLoc
937 ; ty' <- tcIfaceType ty
938 ; return (mkLocalId name ty') }
940 -----------------------
941 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
942 bindIfaceTyVar (occ,kind) thing_inside
943 = do { name <- newIfaceName occ
944 ; let tyvar = mk_iface_tyvar name kind
945 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
947 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
948 bindIfaceTyVars bndrs thing_inside
949 = do { names <- newIfaceNames occs
950 ; let tyvars = zipWith mk_iface_tyvar names kinds
951 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
953 (occs,kinds) = unzip bndrs
955 mk_iface_tyvar name kind = mkTyVar name kind