2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcIfaceSig]{Type checking of type signatures in interface files}
8 tcImportDecl, typecheckIface,
9 tcIfaceKind, loadImportedInsts, loadImportedRules,
12 #include "HsVersions.h"
15 import LoadIface ( loadHomeInterface, predInstGates )
16 import IfaceEnv ( lookupIfaceTop, newGlobalBinder, lookupOrig,
17 extendIfaceIdEnv, extendIfaceTyVarEnv, newIPName,
18 tcIfaceTyVar, tcIfaceTyCon, tcIfaceClass, tcIfaceExtId,
19 tcIfaceDataCon, tcIfaceLclId,
20 newIfaceName, newIfaceNames )
21 import BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, buildClass )
23 import Type ( Kind, openTypeKind, liftedTypeKind,
24 unliftedTypeKind, mkArrowKind, splitTyConApp,
25 mkTyVarTys, mkGenTyConApp, mkTyVarTys, ThetaType )
26 import TypeRep ( Type(..), PredType(..) )
27 import TyCon ( TyCon, tyConName )
28 import HscTypes ( ExternalPackageState(..), PackageInstEnv, PackageRuleBase,
29 HscEnv, TyThing(..), implicitTyThings, typeEnvIds,
30 ModIface(..), ModDetails(..), InstPool,
31 TypeEnv, mkTypeEnv, extendTypeEnvList, lookupTypeEnv,
32 DeclPool, RulePool, Pool(..), Gated, addRuleToPool )
33 import InstEnv ( extendInstEnv )
35 import PprCore ( pprIdRules )
36 import Rules ( extendRuleBaseList )
37 import CoreUtils ( exprType )
39 import CoreLint ( lintUnfolding )
40 import WorkWrap ( mkWrapper )
41 import InstEnv ( DFunId )
42 import Id ( Id, mkVanillaGlobal, mkLocalId )
43 import MkId ( mkFCallId )
44 import IdInfo ( IdInfo, CafInfo(..), WorkerInfo(..),
45 setUnfoldingInfoLazily, setAllStrictnessInfo, setWorkerInfo,
46 setArityInfo, setInlinePragInfo, setCafInfo,
47 vanillaIdInfo, newStrictnessInfo )
48 import Class ( Class )
49 import TyCon ( DataConDetails(..), tyConDataCons, tyConTyVars, isTupleTyCon, mkForeignTyCon )
50 import DataCon ( dataConWorkId, dataConExistentialTyVars, dataConArgTys )
51 import TysWiredIn ( tupleCon )
52 import Var ( TyVar, mkTyVar, tyVarKind )
53 import Name ( Name, NamedThing(..), nameModuleName, nameModule, nameOccName,
54 isWiredInName, wiredInNameTyThing_maybe, nameParent )
56 import OccName ( OccName )
57 import Module ( Module, ModuleName, moduleName )
58 import UniqSupply ( initUs_ )
60 import SrcLoc ( noSrcLoc )
61 import Util ( zipWithEqual, dropList, equalLength )
62 import Maybes ( expectJust )
63 import CmdLineOpts ( DynFlag(..) )
72 An IfaceDecl is populated with RdrNames, and these are not renamed to
73 Names before typechecking, because there should be no scope errors etc.
75 -- For (b) consider: f = $(...h....)
76 -- where h is imported, and calls f via an hi-boot file.
77 -- This is bad! But it is not seen as a staging error, because h
78 -- is indeed imported. We don't want the type-checker to black-hole
79 -- when simplifying and compiling the splice!
81 -- Simple solution: discard any unfolding that mentions a variable
82 -- bound in this module (and hence not yet processed).
83 -- The discarding happens when forkM finds a type error.
85 %************************************************************************
87 %* tcImportDecl is the key function for "faulting in" *
90 %************************************************************************
92 The main idea is this. We are chugging along type-checking source code, and
93 find a reference to GHC.Base.map. We call tcLookupGlobal, which doesn't find
94 it in the EPS type envt. So it
96 2 gets the decl for GHC.Base.map
97 3 typechecks it via tcIfaceDecl
98 4 and adds it to the type env in the EPS
100 Note that DURING STEP 4, we may find that map's type mentions a type
101 constructor that also
103 Notice that for imported things we read the current version from the EPS
104 mutable variable. This is important in situations like
106 where the code that e1 expands to might import some defns that
107 also turn out to be needed by the code that e2 expands to.
110 tcImportDecl :: Name -> IfG TyThing
111 -- Get the TyThing for this Name from an interface file
114 -- Make sure the interface is loaded
115 ; let { nd_doc = ptext SLIT("Need decl for") <+> ppr name }
116 ; traceIf (nd_doc <+> char '{') -- Brace matches the later message
117 ; loadHomeInterface nd_doc name
119 -- Get the real name of the thing, with a correct nameParent field.
120 -- Before the interface is loaded, we may have a non-committal 'Nothing'
121 -- in the namePareent field (made up by IfaceEnv.lookupOrig), but
122 -- loading the interface updates the name cache.
123 -- We need the right nameParent field in getThing
124 ; real_name <- lookupOrig (nameModuleName name) (nameOccName name)
126 -- Get the decl out of the EPS
127 ; main_thing <- ASSERT( real_name == name ) -- Unique should not change!
130 -- Record the import in the type env,
131 -- slurp any rules it allows in
132 ; recordImportOf main_thing
134 ; let { extra | getName main_thing == real_name = empty
135 | otherwise = brackets (ptext SLIT("when seeking") <+> ppr real_name) }
136 ; traceIf (ptext SLIT(" ...imported decl for") <+> ppr main_thing <+> extra <+> char '}')
139 -- Look up the wanted Name in the type envt; it might be
140 -- one of the subordinate members of the input thing
141 ; if real_name == getName main_thing
142 then return main_thing
145 ; return (expectJust "tcImportDecl" $
146 lookupTypeEnv (eps_PTE eps) real_name) }}
148 recordImportOf :: TyThing -> IfG ()
149 -- Update the EPS to record the import of the Thing
150 -- (a) augment the type environment; this is done even for wired-in
151 -- things, so that we don't go through this rigmarole a second time
152 -- (b) slurp in any rules to maintain the invariant that any rule
153 -- whose gates are all in the type envt, is in eps_rule_base
156 = do { new_things <- updateEps (\ eps ->
157 let { new_things = thing : implicitTyThings thing
158 ; new_type_env = extendTypeEnvList (eps_PTE eps) new_things
159 -- NB: opportunity for a very subtle loop here!
160 -- If working out what the implicitTyThings are involves poking
161 -- any of the fork'd thunks in 'thing', then here's what happens
162 -- * recordImportOf succeed, extending type-env with a thunk
163 -- * the next guy to pull on type-env forces the thunk
164 -- * which pokes the suspended forks
165 -- * which, to execute, need to consult type-env (to check
166 -- entirely unrelated types, perhaps)
168 in (eps { eps_PTE = new_type_env }, new_things)
170 ; traceIf (text "tcImport: extend type env" <+> ppr new_things)
173 getThing :: Name -> IfG TyThing
174 -- Find and typecheck the thing; the Name might be a "subordinate name"
175 -- of the "main thing" (e.g. the constructor of a data type declaration)
176 -- The Thing we return is the parent "main thing"
179 | Just thing <- wiredInNameTyThing_maybe name
182 | otherwise = do -- The normal case, not wired in
183 { -- Get the decl from the pool
184 decl <- updateEps (\ eps ->
186 (decls', decl) = selectDecl (eps_decls eps) name
188 (eps { eps_decls = decls' }, decl))
191 -- Side-effects EPS by faulting in any needed decls
192 -- (via nested calls to tcImportDecl)
193 ; initIfaceLcl (nameModuleName name) (tcIfaceDecl decl) }
196 selectDecl :: DeclPool -> Name -> (DeclPool, IfaceDecl)
197 -- Use nameParent to get the parent name of the thing
198 selectDecl (Pool decls_map n_in n_out) name
199 = (Pool decls' n_in (n_out+1), decl)
201 main_name = nameParent name
202 decl = case lookupNameEnv decls_map main_name of
203 Nothing -> pprPanic "selectDecl" (ppr main_name <+> ppr name) ;
206 decls' = delFromNameEnv decls_map main_name
209 %************************************************************************
213 %************************************************************************
216 typecheckIface :: ModIface -> IfG ModDetails
217 -- Used when we decide not to recompile, but intead to use the
218 -- interface to construct the type environment for the module
220 = initIfaceLcl (moduleName (mi_module iface)) $
221 do { ty_things <- mapM (tcIfaceDecl . snd) (mi_decls iface)
222 ; rules <- mapM tcIfaceRule (mi_rules iface)
223 ; dfuns <- mapM tcIfaceInst (mi_insts iface)
224 ; return (ModDetails { md_types = mkTypeEnv ty_things,
226 md_rules = rules }) }
230 %************************************************************************
232 Type and class declarations
234 %************************************************************************
236 When typechecking a data type decl, we *lazily* (via forkM) typecheck
237 the constructor argument types. This is in the hope that we may never
238 poke on those argument types, and hence may never need to load the
239 interface files for types mentioned in the arg types.
242 data Foo.S = MkS Baz.T
243 Mabye we can get away without even loading the interface for Baz!
245 This is not just a performance thing. Suppose we have
246 data Foo.S = MkS Baz.T
247 data Baz.T = MkT Foo.S
248 (in different interface files, of course).
249 Now, first we load and typecheck Foo.S, and add it to the type envt.
250 If we do explore MkS's argument, we'll load and typecheck Baz.T.
251 If we explore MkT's argument we'll find Foo.S already in the envt.
253 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
254 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
255 which isn't done yet.
257 All very cunning. However, there is a rather subtle gotcha which bit
258 me when developing this stuff. When we typecheck the decl for S, we
259 extend the type envt with S, MkS, and all its implicit Ids. Suppose
260 (a bug, but it happened) that the list of implicit Ids depended in
261 turn on the constructor arg types. Then the following sequence of
263 * we build a thunk <t> for the constructor arg tys
264 * we build a thunk for the extended type environment (depends on <t>)
265 * we write the extended type envt into the global EPS mutvar
267 Now we look something up in the type envt
269 * which reads the global type envt out of the global EPS mutvar
270 * but that depends in turn on <t>
272 It's subtle, because, it'd work fine if we typechecked the constructor args
273 eagerly -- they don't need the extended type envt. They just get the extended
274 type envt by accident, because they look at it later.
276 What this means is that the implicitTyThings MUST NOT DEPEND on any of
281 tcIfaceDecl :: IfaceDecl -> IfL TyThing
283 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
284 = do { name <- lookupIfaceTop occ_name
285 ; ty <- tcIfaceType iface_type
286 ; info <- tcIdInfo name ty info
287 ; return (AnId (mkVanillaGlobal name ty info)) }
289 tcIfaceDecl (IfaceData {ifND = new_or_data, ifName = occ_name,
290 ifTyVars = tv_bndrs, ifCtxt = rdr_ctxt,
292 ifVrcs = arg_vrcs, ifRec = is_rec,
293 ifGeneric = want_generic })
294 = do { tc_name <- lookupIfaceTop occ_name
295 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
297 { traceIf (text "tcIfaceDecl" <+> ppr rdr_ctxt)
299 ; ctxt <- forkM (ptext SLIT("Ctxt of data decl") <+> ppr tc_name) $
301 -- The reason for laziness here is to postpone
302 -- looking at the context, because the class may not
303 -- be in the type envt yet. E.g.
304 -- class Real a where { toRat :: a -> Ratio Integer }
305 -- data (Real a) => Ratio a = ...
306 -- We suck in the decl for Real, and type check it, which sucks
307 -- in the data type Ratio; but we must postpone typechecking the
310 ; tycon <- fixM ( \ tycon -> do
311 { cons <- tcIfaceDataCons tycon tyvars ctxt rdr_cons
312 ; tycon <- buildAlgTyCon new_or_data tc_name tyvars ctxt cons
313 arg_vrcs is_rec want_generic
316 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
317 ; return (ATyCon tycon)
320 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
321 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
322 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
323 { tc_name <- lookupIfaceTop occ_name
324 ; rhs_ty <- tcIfaceType rdr_rhs_ty
325 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
328 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
329 ifFDs = rdr_fds, ifSigs = rdr_sigs,
330 ifVrcs = tc_vrcs, ifRec = tc_isrec })
331 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
332 { cls_name <- lookupIfaceTop occ_name
333 ; ctxt <- tcIfaceCtxt rdr_ctxt
334 ; sigs <- mappM tc_sig rdr_sigs
335 ; fds <- mappM tc_fd rdr_fds
336 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
337 ; return (AClass cls) }
339 tc_sig (IfaceClassOp occ dm rdr_ty)
340 = do { op_name <- lookupIfaceTop occ
341 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
342 -- Must be done lazily for just the same reason as the
343 -- context of a data decl: the type sig might mention the
344 -- class being defined
345 ; return (op_name, dm, op_ty) }
347 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
349 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
350 ; tvs2' <- mappM tcIfaceTyVar tvs2
351 ; return (tvs1', tvs2') }
353 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
354 = do { name <- lookupIfaceTop rdr_name
355 ; return (ATyCon (mkForeignTyCon name ext_name
356 liftedTypeKind 0 [])) }
358 tcIfaceDataCons tycon tyvars ctxt Unknown
361 tcIfaceDataCons tycon tyvars ctxt (DataCons cs)
362 = mappM tc_con_decl cs `thenM` \ data_cons ->
363 returnM (DataCons data_cons)
365 tc_con_decl (IfaceConDecl occ ex_tvs ex_ctxt args stricts field_lbls)
366 = bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
367 { name <- lookupIfaceTop occ
368 ; ex_theta <- tcIfaceCtxt ex_ctxt -- Laziness seems not worth the bother here
370 -- Read the argument types, but lazily to avoid faulting in
371 -- the component types unless they are really needed
372 ; arg_tys <- forkM (mk_doc name args) (mappM tcIfaceType args) ;
374 ; lbl_names <- mappM lookupIfaceTop field_lbls
376 ; buildDataCon name stricts lbl_names
377 tyvars ctxt ex_tyvars ex_theta
380 mk_doc con_name args = ptext SLIT("Constructor") <+> sep [ppr con_name, ppr args]
384 %************************************************************************
388 %************************************************************************
390 The gating story for instance declarations
391 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
392 When we are looking for a dict (C t1..tn), we slurp in instance decls for
394 mention at least one of the type constructors
395 at the roots of t1..tn
397 Why "at least one" rather than "all"? Because functional dependencies
398 complicate the picture. Consider
399 class C a b | a->b where ...
400 instance C Foo Baz where ...
401 Here, the gates are really only C and Foo, *not* Baz.
402 That is, if C and Foo are visible, even if Baz isn't, we must
403 slurp the decl, even if Baz is thus far completely unknown to the
406 Why "roots of the types"? Reason is overlap. For example, suppose there
407 are interfaces in the pool for
411 Then, if we are trying to resolve (C Int x), we need (a)
412 if we are trying to resolve (C x [y]), we need *both* (b) and (c),
413 even though T is not involved yet, so that we spot the overlap.
416 loadImportedInsts :: Class -> [Type] -> TcM PackageInstEnv
417 loadImportedInsts cls tys
418 = do { -- Get interfaces for wired-in things, such as Integer
419 -- Any non-wired-in tycons will already be loaded, else
420 -- we couldn't have them in the Type
421 ; this_mod <- getModule
422 ; let { (cls_gate, tc_gates) = predInstGates cls tys
423 ; imp_wi n = isWiredInName n && this_mod /= nameModule n
424 ; wired_tcs = filter imp_wi tc_gates }
425 -- Wired-in tycons not from this module. The "this-module"
426 -- test bites only when compiling Base etc, because loadHomeInterface
427 -- barfs if it's asked to load a non-existent interface
428 ; if null wired_tcs then returnM ()
429 else initIfaceTcRn (mapM_ (loadHomeInterface wired_doc) wired_tcs)
431 ; eps_var <- getEpsVar
432 ; eps <- readMutVar eps_var
434 -- Suck in the instances
435 ; let { (inst_pool', iface_insts)
436 = selectInsts (eps_insts eps) cls_gate tc_gates }
438 -- Empty => finish up rapidly, without writing to eps
439 ; if null iface_insts then
440 return (eps_inst_env eps)
442 { writeMutVar eps_var (eps {eps_insts = inst_pool'})
444 -- Typecheck the new instances
445 ; dfuns <- initIfaceTcRn (mappM tc_inst iface_insts)
447 -- And put them in the package instance environment
448 ; updateEps ( \ eps ->
450 inst_env' = foldl extendInstEnv (eps_inst_env eps) dfuns
452 (eps { eps_inst_env = inst_env' }, inst_env')
455 wired_doc = ptext SLIT("Need home inteface for wired-in thing")
457 tc_inst (mod, inst) = initIfaceLcl mod (tcIfaceInst inst)
459 tcIfaceInst :: IfaceInst -> IfL DFunId
460 tcIfaceInst (IfaceInst { ifDFun = dfun_occ })
461 = tcIfaceExtId (LocalTop dfun_occ)
463 selectInsts :: InstPool -> Name -> [Name] -> (InstPool, [(ModuleName, IfaceInst)])
464 selectInsts pool@(Pool insts n_in n_out) cls tycons
465 = (Pool insts' n_in (n_out + length iface_insts), iface_insts)
467 (insts', iface_insts)
468 = case lookupNameEnv insts cls of {
469 Nothing -> (insts, []) ;
472 case foldl choose ([],[]) gated_insts of {
473 (_, []) -> (insts, []) ; -- None picked
474 (gated_insts', iface_insts') ->
476 (extendNameEnv insts cls gated_insts', iface_insts') }}
478 -- Reverses the gated decls, but that doesn't matter
479 choose (gis, decls) (gates, decl)
480 | any (`elem` tycons) gates = (gis, decl:decls)
481 | otherwise = ((gates,decl) : gis, decls)
484 %************************************************************************
488 %************************************************************************
490 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
491 are in the type environment. However, remember that typechecking a Rule may
492 (as a side effect) augment the type envt, and so we may need to iterate the process.
495 loadImportedRules :: HscEnv -> IO PackageRuleBase
496 loadImportedRules hsc_env
497 = initIfaceIO hsc_env $ do
499 if_rules <- updateEps (\ eps ->
500 let { (new_pool, if_rules) = selectRules (eps_rules eps) (eps_PTE eps) }
501 in (eps { eps_rules = new_pool }, if_rules) )
503 ; let tc_rule (mod, rule) = initIfaceLcl mod (tcIfaceRule rule)
504 ; core_rules <- mapM tc_rule if_rules
507 ; traceIf (ptext SLIT("Importing rules:") <+> pprIdRules core_rules)
509 -- Update the rule base and return it
510 ; updateEps (\ eps ->
511 let { new_rule_base = extendRuleBaseList (eps_rule_base eps) core_rules }
512 in (eps { eps_rule_base = new_rule_base }, new_rule_base)
516 selectRules :: RulePool -> TypeEnv -> (RulePool, [(ModuleName, IfaceRule)])
517 -- Not terribly efficient. Look at each rule in the pool to see if
518 -- all its gates are in the type env. If so, take it out of the pool.
519 -- If not, trim its gates for next time.
520 selectRules (Pool rules n_in n_out) type_env
521 = (Pool rules' n_in (n_out + length if_rules), if_rules)
523 (rules', if_rules) = foldl do_one ([], []) rules
525 do_one (pool, if_rules) (gates, rule)
526 | null gates' = (pool, rule:if_rules)
527 | otherwise = ((gates',rule) : pool, if_rules)
529 gates' = filter (`elemNameEnv` type_env) gates
532 tcIfaceRule :: IfaceRule -> IfL IdCoreRule
533 tcIfaceRule (IfaceRule {ifRuleName = rule_name, ifActivation = act, ifRuleBndrs = bndrs,
534 ifRuleHead = fn_rdr, ifRuleArgs = args, ifRuleRhs = rhs })
535 = bindIfaceBndrs bndrs $ \ bndrs' ->
536 do { fn <- tcIfaceExtId fn_rdr
537 ; args' <- mappM tcIfaceExpr args
538 ; rhs' <- tcIfaceExpr rhs
539 ; returnM (fn, (Rule rule_name act bndrs' args' rhs')) }
541 tcIfaceRule (IfaceBuiltinRule fn_rdr core_rule)
542 = do { fn <- tcIfaceExtId fn_rdr
543 ; returnM (fn, core_rule) }
547 %************************************************************************
551 %************************************************************************
554 tcIfaceKind :: IfaceKind -> Kind
555 tcIfaceKind IfaceOpenTypeKind = openTypeKind
556 tcIfaceKind IfaceLiftedTypeKind = liftedTypeKind
557 tcIfaceKind IfaceUnliftedTypeKind = unliftedTypeKind
558 tcIfaceKind (IfaceFunKind k1 k2) = mkArrowKind (tcIfaceKind k1) (tcIfaceKind k2)
560 -----------------------------------------
561 tcIfaceType :: IfaceType -> IfL Type
562 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
563 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
564 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
565 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkGenTyConApp tc' ts') }
566 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
567 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
569 tcIfaceTypes tys = mapM tcIfaceType tys
571 -----------------------------------------
572 tcIfacePredType :: IfacePredType -> IfL PredType
573 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
574 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
576 -----------------------------------------
577 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
578 tcIfaceCtxt sts = mappM tcIfacePredType sts
582 %************************************************************************
586 %************************************************************************
589 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
590 tcIfaceExpr (IfaceType ty)
591 = tcIfaceType ty `thenM` \ ty' ->
594 tcIfaceExpr (IfaceLcl name)
595 = tcIfaceLclId name `thenM` \ id ->
598 tcIfaceExpr (IfaceExt gbl)
599 = tcIfaceExtId gbl `thenM` \ id ->
602 tcIfaceExpr (IfaceLit lit)
605 tcIfaceExpr (IfaceFCall cc ty)
606 = tcIfaceType ty `thenM` \ ty' ->
607 newUnique `thenM` \ u ->
608 returnM (Var (mkFCallId u cc ty'))
610 tcIfaceExpr (IfaceTuple boxity args)
611 = mappM tcIfaceExpr args `thenM` \ args' ->
613 -- Put the missing type arguments back in
614 con_args = map (Type . exprType) args' ++ args'
616 returnM (mkApps (Var con_id) con_args)
619 con_id = dataConWorkId (tupleCon boxity arity)
622 tcIfaceExpr (IfaceLam bndr body)
623 = bindIfaceBndr bndr $ \ bndr' ->
624 tcIfaceExpr body `thenM` \ body' ->
625 returnM (Lam bndr' body')
627 tcIfaceExpr (IfaceApp fun arg)
628 = tcIfaceExpr fun `thenM` \ fun' ->
629 tcIfaceExpr arg `thenM` \ arg' ->
630 returnM (App fun' arg')
632 tcIfaceExpr (IfaceCase scrut case_bndr alts)
633 = tcIfaceExpr scrut `thenM` \ scrut' ->
634 newIfaceName case_bndr `thenM` \ case_bndr_name ->
636 scrut_ty = exprType scrut'
637 case_bndr' = mkLocalId case_bndr_name scrut_ty
638 tc_app = splitTyConApp scrut_ty
639 -- NB: Won't always succeed (polymoprhic case)
640 -- but won't be demanded in those cases
641 -- NB: not tcSplitTyConApp; we are looking at Core here
642 -- look through non-rec newtypes to find the tycon that
643 -- corresponds to the datacon in this case alternative
645 extendIfaceIdEnv [case_bndr'] $
646 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
647 returnM (Case scrut' case_bndr' alts')
649 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
650 = tcIfaceExpr rhs `thenM` \ rhs' ->
651 bindIfaceId bndr $ \ bndr' ->
652 tcIfaceExpr body `thenM` \ body' ->
653 returnM (Let (NonRec bndr' rhs') body')
655 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
656 = bindIfaceIds bndrs $ \ bndrs' ->
657 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
658 tcIfaceExpr body `thenM` \ body' ->
659 returnM (Let (Rec (bndrs' `zip` rhss')) body')
661 (bndrs, rhss) = unzip pairs
663 tcIfaceExpr (IfaceNote note expr)
664 = tcIfaceExpr expr `thenM` \ expr' ->
666 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
667 returnM (Note (Coerce to_ty'
668 (exprType expr')) expr')
669 IfaceInlineCall -> returnM (Note InlineCall expr')
670 IfaceInlineMe -> returnM (Note InlineMe expr')
671 IfaceSCC cc -> returnM (Note (SCC cc) expr')
672 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
674 -------------------------
675 tcIfaceAlt _ (IfaceDefault, names, rhs)
676 = ASSERT( null names )
677 tcIfaceExpr rhs `thenM` \ rhs' ->
678 returnM (DEFAULT, [], rhs')
680 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
681 = ASSERT( null names )
682 tcIfaceExpr rhs `thenM` \ rhs' ->
683 returnM (LitAlt lit, [], rhs')
685 -- A case alternative is made quite a bit more complicated
686 -- by the fact that we omit type annotations because we can
687 -- work them out. True enough, but its not that easy!
688 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
690 tycon_mod = nameModuleName (tyConName tycon)
692 tcIfaceDataCon (ExtPkg tycon_mod data_occ) `thenM` \ con ->
693 newIfaceNames arg_occs `thenM` \ arg_names ->
695 ex_tyvars = dataConExistentialTyVars con
696 main_tyvars = tyConTyVars tycon
697 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- arg_names `zip` ex_tyvars]
698 ex_tys' = mkTyVarTys ex_tyvars'
699 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
700 id_names = dropList ex_tyvars arg_names
703 | not (equalLength id_names arg_tys)
704 = pprPanic "tcIfaceAlts" (ppr (con, arg_names, rhs) $$
705 (ppr main_tyvars <+> ppr ex_tyvars) $$
709 = zipWithEqual "tcIfaceAlts" mkLocalId id_names arg_tys
711 ASSERT2( con `elem` tyConDataCons tycon && equalLength inst_tys main_tyvars,
712 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) $$ ppr arg_tys $$ ppr main_tyvars )
713 extendIfaceTyVarEnv ex_tyvars' $
714 extendIfaceIdEnv arg_ids $
715 tcIfaceExpr rhs `thenM` \ rhs' ->
716 returnM (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
718 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
719 = newIfaceNames arg_occs `thenM` \ arg_names ->
721 [con] = tyConDataCons tycon
722 arg_ids = zipWithEqual "tcIfaceAlts" mkLocalId arg_names inst_tys
724 ASSERT( isTupleTyCon tycon )
725 extendIfaceIdEnv arg_ids $
726 tcIfaceExpr rhs `thenM` \ rhs' ->
727 returnM (DataAlt con, arg_ids, rhs')
732 tcExtCoreBindings :: Module -> [IfaceBinding] -> IfL [CoreBind] -- Used for external core
733 tcExtCoreBindings mod [] = return []
734 tcExtCoreBindings mod (b:bs) = do_one mod b (tcExtCoreBindings mod bs)
736 do_one :: Module -> IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
737 do_one mod (IfaceNonRec bndr rhs) thing_inside
738 = do { rhs' <- tcIfaceExpr rhs
739 ; bndr' <- newExtCoreBndr mod bndr
740 ; extendIfaceIdEnv [bndr'] $ do
741 { core_binds <- thing_inside
742 ; return (NonRec bndr' rhs' : core_binds) }}
744 do_one mod (IfaceRec pairs) thing_inside
745 = do { bndrs' <- mappM (newExtCoreBndr mod) bndrs
746 ; extendIfaceIdEnv bndrs' $ do
747 { rhss' <- mappM tcIfaceExpr rhss
748 ; core_binds <- thing_inside
749 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
751 (bndrs,rhss) = unzip pairs
755 %************************************************************************
759 %************************************************************************
762 tcIdInfo name ty NoInfo = return vanillaIdInfo
763 tcIdInfo name ty DiscardedInfo = return vanillaIdInfo
764 tcIdInfo name ty (HasInfo iface_info)
765 = foldlM tcPrag init_info iface_info
767 -- Set the CgInfo to something sensible but uninformative before
768 -- we start; default assumption is that it has CAFs
769 init_info = vanillaIdInfo
771 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
772 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
773 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
775 -- The next two are lazy, so they don't transitively suck stuff in
776 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
777 tcPrag info (HsUnfold inline_prag expr)
778 = tcPragExpr name expr `thenM` \ maybe_expr' ->
780 -- maybe_expr' doesn't get looked at if the unfolding
781 -- is never inspected; so the typecheck doesn't even happen
782 unfold_info = case maybe_expr' of
783 Nothing -> noUnfolding
784 Just expr' -> mkTopUnfolding expr'
786 returnM (info `setUnfoldingInfoLazily` unfold_info
787 `setInlinePragInfo` inline_prag)
791 tcWorkerInfo ty info wkr_name arity
792 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId (LocalTop wkr_name))
794 -- We return without testing maybe_wkr_id, but as soon as info is
795 -- looked at we will test it. That's ok, because its outside the
796 -- knot; and there seems no big reason to further defer the
797 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
798 -- over the unfolding until it's actually used does seem worth while.)
799 ; us <- newUniqueSupply
801 ; returnM (case mb_wkr_id of
803 Just wkr_id -> add_wkr_info us wkr_id info) }
805 doc = text "Worker for" <+> ppr wkr_name
806 add_wkr_info us wkr_id info
807 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
808 `setWorkerInfo` HasWorker wkr_id arity
810 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
812 -- We are relying here on strictness info always appearing
813 -- before worker info, fingers crossed ....
814 strict_sig = case newStrictnessInfo info of
816 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr_name)
819 For unfoldings we try to do the job lazily, so that we never type check
820 an unfolding that isn't going to be looked at.
823 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
826 tcIfaceExpr expr `thenM` \ core_expr' ->
828 -- Check for type consistency in the unfolding
829 ifOptM Opt_DoCoreLinting (
830 get_in_scope_ids `thenM` \ in_scope ->
831 case lintUnfolding noSrcLoc in_scope core_expr' of
832 Nothing -> returnM ()
833 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
838 doc = text "Unfolding of" <+> ppr name
839 get_in_scope_ids -- Urgh; but just for linting
841 do { env <- getGblEnv
842 ; case if_rec_types env of {
843 Nothing -> return [] ;
844 Just (_, get_env) -> do
845 { type_env <- get_env
846 ; return (typeEnvIds type_env) }}}
851 %************************************************************************
855 %************************************************************************
858 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
859 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
860 = bindIfaceId bndr thing_inside
861 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
862 = bindIfaceTyVar bndr thing_inside
864 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
865 bindIfaceBndrs [] thing_inside = thing_inside []
866 bindIfaceBndrs (b:bs) thing_inside
867 = bindIfaceBndr b $ \ b' ->
868 bindIfaceBndrs bs $ \ bs' ->
869 thing_inside (b':bs')
871 -----------------------
872 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
873 bindIfaceId (occ, ty) thing_inside
874 = do { name <- newIfaceName occ
875 ; ty' <- tcIfaceType ty
876 ; let { id = mkLocalId name ty' }
877 ; extendIfaceIdEnv [id] (thing_inside id) }
879 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
880 bindIfaceIds bndrs thing_inside
881 = do { names <- newIfaceNames occs
882 ; tys' <- mappM tcIfaceType tys
883 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
884 ; extendIfaceIdEnv ids (thing_inside ids) }
886 (occs,tys) = unzip bndrs
889 -----------------------
890 newExtCoreBndr :: Module -> (OccName, IfaceType) -> IfL Id
891 newExtCoreBndr mod (occ, ty)
892 = do { name <- newGlobalBinder mod occ Nothing noSrcLoc
893 ; ty' <- tcIfaceType ty
894 ; return (mkLocalId name ty') }
896 -----------------------
897 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
898 bindIfaceTyVar (occ,kind) thing_inside
899 = do { name <- newIfaceName occ
900 ; let tyvar = mk_iface_tyvar name kind
901 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
903 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
904 bindIfaceTyVars bndrs thing_inside
905 = do { names <- newIfaceNames occs
906 ; let tyvars = zipWith mk_iface_tyvar names kinds
907 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
909 (occs,kinds) = unzip bndrs
911 mk_iface_tyvar name kind = mkTyVar name (tcIfaceKind kind)