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 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, pprClassPred )
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, ModGuts,
31 TypeEnv, mkTypeEnv, extendTypeEnvList, lookupTypeEnv,
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, zipLazy )
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 mb_decl <- updateEps (\ eps -> selectDecl eps name)
187 Just decl -> initIfaceLcl (nameModuleName name) (tcIfaceDecl decl)
189 -- Side-effects EPS by faulting in any needed decls
190 -- (via nested calls to tcImportDecl)
193 Nothing -> do { ioToIOEnv (printErrs (msg defaultErrStyle)); failM }
194 -- Declaration not found
195 -- No errors-var to accumulate errors in, so just
196 -- print out the error right now
200 msg = hang (ptext SLIT("Can't find interface-file declaration for") <+> ppr (nameParent name))
201 2 (vcat [ptext SLIT("Probable cause: bug in .hi-boot file, or inconsistent .hi file"),
202 ptext SLIT("Use -ddump-if-trace to get an idea of which file caused the error")])
204 selectDecl :: ExternalPackageState -> Name -> (ExternalPackageState, Maybe IfaceDecl)
205 -- Use nameParent to get the parent name of the thing
206 selectDecl eps@(EPS { eps_decls = Pool decls_map n_in n_out}) name
207 = case lookupNameEnv decls_map main_name of
208 Nothing -> (eps, Nothing)
209 Just decl -> (eps {eps_decls = Pool decls' n_in (n_out+1)}, Just decl)
211 main_name = nameParent name
212 decls' = delFromNameEnv decls_map main_name
215 %************************************************************************
217 Type-checking a complete interface
219 %************************************************************************
221 Suppose we discover we don't need to recompile. Then we must type
222 check the old interface file. This is a bit different to the
223 incremental type checking we do as we suck in interface files. Instead
224 we do things similarly as when we are typechecking source decls: we
225 bring into scope the type envt for the interface all at once, using a
226 knot. Remember, the decls aren't necessarily in dependency order --
227 and even if they were, the type decls might be mutually recursive.
230 typecheckIface :: HscEnv
231 -> ModIface -- Get the decls from here
233 typecheckIface hsc_env iface@(ModIface { mi_module = mod, mi_decls = ver_decls,
234 mi_rules = rules, mi_insts = dfuns })
235 = initIfaceTc hsc_env iface $ \ tc_env_var -> do
236 { -- Typecheck the decls
237 names <- mappM (lookupOrig (moduleName mod) . ifName) decls
238 ; ty_things <- fixM (\ rec_ty_things -> do
239 { writeMutVar tc_env_var (mkNameEnv (names `zipLazy` rec_ty_things))
240 -- This only makes available the "main" things,
241 -- but that's enough for the strictly-checked part
242 ; mapM tcIfaceDecl decls })
244 -- Now augment the type envt with all the implicit things
245 -- These will be needed when type-checking the unfoldings for
246 -- the IfaceIds, but this is done lazily, so writing the thing
248 ; let { add_implicits main_thing = main_thing : implicitTyThings main_thing
249 ; type_env = mkTypeEnv (concatMap add_implicits ty_things) }
250 ; writeMutVar tc_env_var type_env
252 -- Now do those rules and instances
253 ; dfuns <- mapM tcIfaceInst (mi_insts iface)
254 ; rules <- mapM tcIfaceRule (mi_rules iface)
257 ; return (ModDetails { md_types = type_env, md_insts = dfuns, md_rules = rules })
260 decls = map snd ver_decls
264 %************************************************************************
266 Type and class declarations
268 %************************************************************************
270 When typechecking a data type decl, we *lazily* (via forkM) typecheck
271 the constructor argument types. This is in the hope that we may never
272 poke on those argument types, and hence may never need to load the
273 interface files for types mentioned in the arg types.
276 data Foo.S = MkS Baz.T
277 Mabye we can get away without even loading the interface for Baz!
279 This is not just a performance thing. Suppose we have
280 data Foo.S = MkS Baz.T
281 data Baz.T = MkT Foo.S
282 (in different interface files, of course).
283 Now, first we load and typecheck Foo.S, and add it to the type envt.
284 If we do explore MkS's argument, we'll load and typecheck Baz.T.
285 If we explore MkT's argument we'll find Foo.S already in the envt.
287 If we typechecked constructor args eagerly, when loading Foo.S we'd try to
288 typecheck the type Baz.T. So we'd fault in Baz.T... and then need Foo.S...
289 which isn't done yet.
291 All very cunning. However, there is a rather subtle gotcha which bit
292 me when developing this stuff. When we typecheck the decl for S, we
293 extend the type envt with S, MkS, and all its implicit Ids. Suppose
294 (a bug, but it happened) that the list of implicit Ids depended in
295 turn on the constructor arg types. Then the following sequence of
297 * we build a thunk <t> for the constructor arg tys
298 * we build a thunk for the extended type environment (depends on <t>)
299 * we write the extended type envt into the global EPS mutvar
301 Now we look something up in the type envt
303 * which reads the global type envt out of the global EPS mutvar
304 * but that depends in turn on <t>
306 It's subtle, because, it'd work fine if we typechecked the constructor args
307 eagerly -- they don't need the extended type envt. They just get the extended
308 type envt by accident, because they look at it later.
310 What this means is that the implicitTyThings MUST NOT DEPEND on any of
315 tcIfaceDecl :: IfaceDecl -> IfL TyThing
317 tcIfaceDecl (IfaceId {ifName = occ_name, ifType = iface_type, ifIdInfo = info})
318 = do { name <- lookupIfaceTop occ_name
319 ; ty <- tcIfaceType iface_type
320 ; info <- tcIdInfo name ty info
321 ; return (AnId (mkVanillaGlobal name ty info)) }
323 tcIfaceDecl (IfaceData {ifND = new_or_data, ifName = occ_name,
324 ifTyVars = tv_bndrs, ifCtxt = rdr_ctxt,
326 ifVrcs = arg_vrcs, ifRec = is_rec,
327 ifGeneric = want_generic })
328 = do { tc_name <- lookupIfaceTop occ_name
329 ; bindIfaceTyVars tv_bndrs $ \ tyvars -> do
331 { traceIf (text "tcIfaceDecl" <+> ppr rdr_ctxt)
333 ; ctxt <- forkM (ptext SLIT("Ctxt of data decl") <+> ppr tc_name) $
335 -- The reason for laziness here is to postpone
336 -- looking at the context, because the class may not
337 -- be in the type envt yet. E.g.
338 -- class Real a where { toRat :: a -> Ratio Integer }
339 -- data (Real a) => Ratio a = ...
340 -- We suck in the decl for Real, and type check it, which sucks
341 -- in the data type Ratio; but we must postpone typechecking the
344 ; tycon <- fixM ( \ tycon -> do
345 { cons <- tcIfaceDataCons tycon tyvars ctxt rdr_cons
346 ; tycon <- buildAlgTyCon new_or_data tc_name tyvars ctxt cons
347 arg_vrcs is_rec want_generic
350 ; traceIf (text "tcIfaceDecl4" <+> ppr tycon)
351 ; return (ATyCon tycon)
354 tcIfaceDecl (IfaceSyn {ifName = occ_name, ifTyVars = tv_bndrs,
355 ifSynRhs = rdr_rhs_ty, ifVrcs = arg_vrcs})
356 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
357 { tc_name <- lookupIfaceTop occ_name
358 ; rhs_ty <- tcIfaceType rdr_rhs_ty
359 ; return (ATyCon (buildSynTyCon tc_name tyvars rhs_ty arg_vrcs))
362 tcIfaceDecl (IfaceClass {ifCtxt = rdr_ctxt, ifName = occ_name, ifTyVars = tv_bndrs,
363 ifFDs = rdr_fds, ifSigs = rdr_sigs,
364 ifVrcs = tc_vrcs, ifRec = tc_isrec })
365 = bindIfaceTyVars tv_bndrs $ \ tyvars -> do
366 { cls_name <- lookupIfaceTop occ_name
367 ; ctxt <- tcIfaceCtxt rdr_ctxt
368 ; sigs <- mappM tc_sig rdr_sigs
369 ; fds <- mappM tc_fd rdr_fds
370 ; cls <- buildClass cls_name tyvars ctxt fds sigs tc_isrec tc_vrcs
371 ; return (AClass cls) }
373 tc_sig (IfaceClassOp occ dm rdr_ty)
374 = do { op_name <- lookupIfaceTop occ
375 ; op_ty <- forkM (mk_doc op_name rdr_ty) (tcIfaceType rdr_ty)
376 -- Must be done lazily for just the same reason as the
377 -- context of a data decl: the type sig might mention the
378 -- class being defined
379 ; return (op_name, dm, op_ty) }
381 mk_doc op_name op_ty = ptext SLIT("Class op") <+> sep [ppr op_name, ppr op_ty]
383 tc_fd (tvs1, tvs2) = do { tvs1' <- mappM tcIfaceTyVar tvs1
384 ; tvs2' <- mappM tcIfaceTyVar tvs2
385 ; return (tvs1', tvs2') }
387 tcIfaceDecl (IfaceForeign {ifName = rdr_name, ifExtName = ext_name})
388 = do { name <- lookupIfaceTop rdr_name
389 ; return (ATyCon (mkForeignTyCon name ext_name
390 liftedTypeKind 0 [])) }
392 tcIfaceDataCons tycon tyvars ctxt Unknown
395 tcIfaceDataCons tycon tyvars ctxt (DataCons cs)
396 = mappM tc_con_decl cs `thenM` \ data_cons ->
397 returnM (DataCons data_cons)
399 tc_con_decl (IfaceConDecl occ ex_tvs ex_ctxt args stricts field_lbls)
400 = bindIfaceTyVars ex_tvs $ \ ex_tyvars -> do
401 { name <- lookupIfaceTop occ
402 ; ex_theta <- tcIfaceCtxt ex_ctxt -- Laziness seems not worth the bother here
404 -- Read the argument types, but lazily to avoid faulting in
405 -- the component types unless they are really needed
406 ; arg_tys <- forkM (mk_doc name args) (mappM tcIfaceType args) ;
408 ; lbl_names <- mappM lookupIfaceTop field_lbls
410 ; buildDataCon name stricts lbl_names
411 tyvars ctxt ex_tyvars ex_theta
414 mk_doc con_name args = ptext SLIT("Constructor") <+> sep [ppr con_name, ppr args]
418 %************************************************************************
422 %************************************************************************
424 The gating story for instance declarations
425 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
426 When we are looking for a dict (C t1..tn), we slurp in instance decls for
428 mention at least one of the type constructors
429 at the roots of t1..tn
431 Why "at least one" rather than "all"? Because functional dependencies
432 complicate the picture. Consider
433 class C a b | a->b where ...
434 instance C Foo Baz where ...
435 Here, the gates are really only C and Foo, *not* Baz.
436 That is, if C and Foo are visible, even if Baz isn't, we must
437 slurp the decl, even if Baz is thus far completely unknown to the
440 Why "roots of the types"? Reason is overlap. For example, suppose there
441 are interfaces in the pool for
445 Then, if we are trying to resolve (C Int x), we need (a)
446 if we are trying to resolve (C x [y]), we need *both* (b) and (c),
447 even though T is not involved yet, so that we spot the overlap.
450 NOTE: if you use an instance decl with NO type constructors
451 instance C a where ...
452 and look up an Inst that only has type variables such as (C (n o))
453 then GHC won't necessarily suck in the instances that overlap with this.
457 loadImportedInsts :: Class -> [Type] -> TcM PackageInstEnv
458 loadImportedInsts cls tys
459 = do { -- Get interfaces for wired-in things, such as Integer
460 -- Any non-wired-in tycons will already be loaded, else
461 -- we couldn't have them in the Type
462 ; this_mod <- getModule
463 ; let { (cls_gate, tc_gates) = predInstGates cls tys
464 ; imp_wi n = isWiredInName n && this_mod /= nameModule n
465 ; wired_tcs = filter imp_wi tc_gates }
466 -- Wired-in tycons not from this module. The "this-module"
467 -- test bites only when compiling Base etc, because loadHomeInterface
468 -- barfs if it's asked to load a non-existent interface
469 ; if null wired_tcs then returnM ()
470 else initIfaceTcRn (mapM_ (loadHomeInterface wired_doc) wired_tcs)
472 ; eps_var <- getEpsVar
473 ; eps <- readMutVar eps_var
475 -- Suck in the instances
476 ; let { (inst_pool', iface_insts)
477 = WARN( null tc_gates, ptext SLIT("Interesting! No tycons in Inst:")
478 <+> pprClassPred cls tys )
479 selectInsts (eps_insts eps) cls_gate tc_gates }
481 -- Empty => finish up rapidly, without writing to eps
482 ; if null iface_insts then
483 return (eps_inst_env eps)
485 { writeMutVar eps_var (eps {eps_insts = inst_pool'})
487 ; traceIf (sep [ptext SLIT("Importing instances for") <+> pprClassPred cls tys,
488 nest 2 (vcat (map ppr iface_insts))])
490 -- Typecheck the new instances
491 ; dfuns <- initIfaceTcRn (mappM tc_inst iface_insts)
493 -- And put them in the package instance environment
494 ; updateEps ( \ eps ->
496 inst_env' = foldl extendInstEnv (eps_inst_env eps) dfuns
498 (eps { eps_inst_env = inst_env' }, inst_env')
501 wired_doc = ptext SLIT("Need home inteface for wired-in thing")
503 tc_inst (mod, inst) = initIfaceLcl mod (tcIfaceInst inst)
505 tcIfaceInst :: IfaceInst -> IfL DFunId
506 tcIfaceInst (IfaceInst { ifDFun = dfun_occ })
507 = tcIfaceExtId (LocalTop dfun_occ)
509 selectInsts :: InstPool -> Name -> [Name] -> (InstPool, [(ModuleName, IfaceInst)])
510 selectInsts pool@(Pool insts n_in n_out) cls tycons
511 = (Pool insts' n_in (n_out + length iface_insts), iface_insts)
513 (insts', iface_insts)
514 = case lookupNameEnv insts cls of {
515 Nothing -> (insts, []) ;
518 case choose1 gated_insts of {
519 (_, []) -> (insts, []) ; -- None picked
520 (gated_insts', iface_insts') ->
522 (extendNameEnv insts cls gated_insts', iface_insts') }}
525 | null tycons -- Bizarre special case of C (a b); then there are no tycons
526 = ([], map snd gated_insts) -- Just grab all the instances, no real alternative
527 | otherwise -- Normal case
528 = foldl choose2 ([],[]) gated_insts
530 -- Reverses the gated decls, but that doesn't matter
531 choose2 (gis, decls) (gates, decl)
532 | null gates -- Happens when we have 'instance T a where ...'
533 || any (`elem` tycons) gates = (gis, decl:decls)
534 | otherwise = ((gates,decl) : gis, decls)
537 %************************************************************************
541 %************************************************************************
543 We move a IfaceRule from eps_rules to eps_rule_base when all its LHS free vars
544 are in the type environment. However, remember that typechecking a Rule may
545 (as a side effect) augment the type envt, and so we may need to iterate the process.
548 loadImportedRules :: HscEnv -> ModGuts -> IO PackageRuleBase
549 loadImportedRules hsc_env guts
550 = initIfaceRules hsc_env guts $ do
552 if_rules <- updateEps (\ eps ->
553 let { (new_pool, if_rules) = selectRules (eps_rules eps) (eps_PTE eps) }
554 in (eps { eps_rules = new_pool }, if_rules) )
556 ; traceIf (ptext SLIT("Importing rules:") <+> vcat (map ppr if_rules))
558 ; let tc_rule (mod, rule) = initIfaceLcl mod (tcIfaceRule rule)
559 ; core_rules <- mapM tc_rule if_rules
562 ; traceIf (ptext SLIT("Imported rules:") <+> pprIdRules core_rules)
564 -- Update the rule base and return it
565 ; updateEps (\ eps ->
566 let { new_rule_base = extendRuleBaseList (eps_rule_base eps) core_rules }
567 in (eps { eps_rule_base = new_rule_base }, new_rule_base)
570 -- Strictly speaking, at this point we should go round again, since
571 -- typechecking one set of rules may bring in new things which enable
572 -- some more rules to come in. But we call loadImportedRules several
573 -- times anyway, so I'm going to be lazy and ignore this.
577 selectRules :: RulePool -> TypeEnv -> (RulePool, [(ModuleName, IfaceRule)])
578 -- Not terribly efficient. Look at each rule in the pool to see if
579 -- all its gates are in the type env. If so, take it out of the pool.
580 -- If not, trim its gates for next time.
581 selectRules (Pool rules n_in n_out) type_env
582 = (Pool rules' n_in (n_out + length if_rules), if_rules)
584 (rules', if_rules) = foldl do_one ([], []) rules
586 do_one (pool, if_rules) (gates, rule)
587 | null gates' = (pool, rule:if_rules)
588 | otherwise = ((gates',rule) : pool, if_rules)
590 gates' = filter (not . (`elemNameEnv` type_env)) gates
593 tcIfaceRule :: IfaceRule -> IfL IdCoreRule
594 tcIfaceRule (IfaceRule {ifRuleName = rule_name, ifActivation = act, ifRuleBndrs = bndrs,
595 ifRuleHead = fn_rdr, ifRuleArgs = args, ifRuleRhs = rhs })
596 = bindIfaceBndrs bndrs $ \ bndrs' ->
597 do { fn <- tcIfaceExtId fn_rdr
598 ; args' <- mappM tcIfaceExpr args
599 ; rhs' <- tcIfaceExpr rhs
600 ; returnM (fn, (Rule rule_name act bndrs' args' rhs')) }
602 tcIfaceRule (IfaceBuiltinRule fn_rdr core_rule)
603 = do { fn <- tcIfaceExtId fn_rdr
604 ; returnM (fn, core_rule) }
608 %************************************************************************
612 %************************************************************************
615 tcIfaceType :: IfaceType -> IfL Type
616 tcIfaceType (IfaceTyVar n) = do { tv <- tcIfaceTyVar n; return (TyVarTy tv) }
617 tcIfaceType (IfaceAppTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (AppTy t1' t2') }
618 tcIfaceType (IfaceFunTy t1 t2) = do { t1' <- tcIfaceType t1; t2' <- tcIfaceType t2; return (FunTy t1' t2') }
619 tcIfaceType (IfaceTyConApp tc ts) = do { tc' <- tcIfaceTyCon tc; ts' <- tcIfaceTypes ts; return (mkGenTyConApp tc' ts') }
620 tcIfaceType (IfaceForAllTy tv t) = bindIfaceTyVar tv $ \ tv' -> do { t' <- tcIfaceType t; return (ForAllTy tv' t') }
621 tcIfaceType (IfacePredTy st) = do { st' <- tcIfacePredType st; return (PredTy st') }
623 tcIfaceTypes tys = mapM tcIfaceType tys
625 -----------------------------------------
626 tcIfacePredType :: IfacePredType -> IfL PredType
627 tcIfacePredType (IfaceClassP cls ts) = do { cls' <- tcIfaceClass cls; ts' <- tcIfaceTypes ts; return (ClassP cls' ts') }
628 tcIfacePredType (IfaceIParam ip t) = do { ip' <- newIPName ip; t' <- tcIfaceType t; return (IParam ip' t') }
630 -----------------------------------------
631 tcIfaceCtxt :: IfaceContext -> IfL ThetaType
632 tcIfaceCtxt sts = mappM tcIfacePredType sts
636 %************************************************************************
640 %************************************************************************
643 tcIfaceExpr :: IfaceExpr -> IfL CoreExpr
644 tcIfaceExpr (IfaceType ty)
645 = tcIfaceType ty `thenM` \ ty' ->
648 tcIfaceExpr (IfaceLcl name)
649 = tcIfaceLclId name `thenM` \ id ->
652 tcIfaceExpr (IfaceExt gbl)
653 = tcIfaceExtId gbl `thenM` \ id ->
656 tcIfaceExpr (IfaceLit lit)
659 tcIfaceExpr (IfaceFCall cc ty)
660 = tcIfaceType ty `thenM` \ ty' ->
661 newUnique `thenM` \ u ->
662 returnM (Var (mkFCallId u cc ty'))
664 tcIfaceExpr (IfaceTuple boxity args)
665 = mappM tcIfaceExpr args `thenM` \ args' ->
667 -- Put the missing type arguments back in
668 con_args = map (Type . exprType) args' ++ args'
670 returnM (mkApps (Var con_id) con_args)
673 con_id = dataConWorkId (tupleCon boxity arity)
676 tcIfaceExpr (IfaceLam bndr body)
677 = bindIfaceBndr bndr $ \ bndr' ->
678 tcIfaceExpr body `thenM` \ body' ->
679 returnM (Lam bndr' body')
681 tcIfaceExpr (IfaceApp fun arg)
682 = tcIfaceExpr fun `thenM` \ fun' ->
683 tcIfaceExpr arg `thenM` \ arg' ->
684 returnM (App fun' arg')
686 tcIfaceExpr (IfaceCase scrut case_bndr alts)
687 = tcIfaceExpr scrut `thenM` \ scrut' ->
688 newIfaceName case_bndr `thenM` \ case_bndr_name ->
690 scrut_ty = exprType scrut'
691 case_bndr' = mkLocalId case_bndr_name scrut_ty
692 tc_app = splitTyConApp scrut_ty
693 -- NB: Won't always succeed (polymoprhic case)
694 -- but won't be demanded in those cases
695 -- NB: not tcSplitTyConApp; we are looking at Core here
696 -- look through non-rec newtypes to find the tycon that
697 -- corresponds to the datacon in this case alternative
699 extendIfaceIdEnv [case_bndr'] $
700 mappM (tcIfaceAlt tc_app) alts `thenM` \ alts' ->
701 returnM (Case scrut' case_bndr' alts')
703 tcIfaceExpr (IfaceLet (IfaceNonRec bndr rhs) body)
704 = tcIfaceExpr rhs `thenM` \ rhs' ->
705 bindIfaceId bndr $ \ bndr' ->
706 tcIfaceExpr body `thenM` \ body' ->
707 returnM (Let (NonRec bndr' rhs') body')
709 tcIfaceExpr (IfaceLet (IfaceRec pairs) body)
710 = bindIfaceIds bndrs $ \ bndrs' ->
711 mappM tcIfaceExpr rhss `thenM` \ rhss' ->
712 tcIfaceExpr body `thenM` \ body' ->
713 returnM (Let (Rec (bndrs' `zip` rhss')) body')
715 (bndrs, rhss) = unzip pairs
717 tcIfaceExpr (IfaceNote note expr)
718 = tcIfaceExpr expr `thenM` \ expr' ->
720 IfaceCoerce to_ty -> tcIfaceType to_ty `thenM` \ to_ty' ->
721 returnM (Note (Coerce to_ty'
722 (exprType expr')) expr')
723 IfaceInlineCall -> returnM (Note InlineCall expr')
724 IfaceInlineMe -> returnM (Note InlineMe expr')
725 IfaceSCC cc -> returnM (Note (SCC cc) expr')
726 IfaceCoreNote n -> returnM (Note (CoreNote n) expr')
728 -------------------------
729 tcIfaceAlt _ (IfaceDefault, names, rhs)
730 = ASSERT( null names )
731 tcIfaceExpr rhs `thenM` \ rhs' ->
732 returnM (DEFAULT, [], rhs')
734 tcIfaceAlt _ (IfaceLitAlt lit, names, rhs)
735 = ASSERT( null names )
736 tcIfaceExpr rhs `thenM` \ rhs' ->
737 returnM (LitAlt lit, [], rhs')
739 -- A case alternative is made quite a bit more complicated
740 -- by the fact that we omit type annotations because we can
741 -- work them out. True enough, but its not that easy!
742 tcIfaceAlt (tycon, inst_tys) (IfaceDataAlt data_occ, arg_occs, rhs)
744 tycon_mod = nameModuleName (tyConName tycon)
746 tcIfaceDataCon (ExtPkg tycon_mod data_occ) `thenM` \ con ->
747 newIfaceNames arg_occs `thenM` \ arg_names ->
749 ex_tyvars = dataConExistentialTyVars con
750 main_tyvars = tyConTyVars tycon
751 ex_tyvars' = [mkTyVar name (tyVarKind tv) | (name,tv) <- arg_names `zip` ex_tyvars]
752 ex_tys' = mkTyVarTys ex_tyvars'
753 arg_tys = dataConArgTys con (inst_tys ++ ex_tys')
754 id_names = dropList ex_tyvars arg_names
757 | not (equalLength id_names arg_tys)
758 = pprPanic "tcIfaceAlts" (ppr (con, arg_names, rhs) $$
759 (ppr main_tyvars <+> ppr ex_tyvars) $$
763 = zipWithEqual "tcIfaceAlts" mkLocalId id_names arg_tys
765 ASSERT2( con `elem` tyConDataCons tycon && equalLength inst_tys main_tyvars,
766 ppr con $$ ppr tycon $$ ppr (tyConDataCons tycon) $$ ppr arg_tys $$ ppr main_tyvars )
767 extendIfaceTyVarEnv ex_tyvars' $
768 extendIfaceIdEnv arg_ids $
769 tcIfaceExpr rhs `thenM` \ rhs' ->
770 returnM (DataAlt con, ex_tyvars' ++ arg_ids, rhs')
772 tcIfaceAlt (tycon, inst_tys) (IfaceTupleAlt boxity, arg_occs, rhs)
773 = newIfaceNames arg_occs `thenM` \ arg_names ->
775 [con] = tyConDataCons tycon
776 arg_ids = zipWithEqual "tcIfaceAlts" mkLocalId arg_names inst_tys
778 ASSERT( isTupleTyCon tycon )
779 extendIfaceIdEnv arg_ids $
780 tcIfaceExpr rhs `thenM` \ rhs' ->
781 returnM (DataAlt con, arg_ids, rhs')
786 tcExtCoreBindings :: Module -> [IfaceBinding] -> IfL [CoreBind] -- Used for external core
787 tcExtCoreBindings mod [] = return []
788 tcExtCoreBindings mod (b:bs) = do_one mod b (tcExtCoreBindings mod bs)
790 do_one :: Module -> IfaceBinding -> IfL [CoreBind] -> IfL [CoreBind]
791 do_one mod (IfaceNonRec bndr rhs) thing_inside
792 = do { rhs' <- tcIfaceExpr rhs
793 ; bndr' <- newExtCoreBndr mod bndr
794 ; extendIfaceIdEnv [bndr'] $ do
795 { core_binds <- thing_inside
796 ; return (NonRec bndr' rhs' : core_binds) }}
798 do_one mod (IfaceRec pairs) thing_inside
799 = do { bndrs' <- mappM (newExtCoreBndr mod) bndrs
800 ; extendIfaceIdEnv bndrs' $ do
801 { rhss' <- mappM tcIfaceExpr rhss
802 ; core_binds <- thing_inside
803 ; return (Rec (bndrs' `zip` rhss') : core_binds) }}
805 (bndrs,rhss) = unzip pairs
809 %************************************************************************
813 %************************************************************************
816 tcIdInfo name ty NoInfo = return vanillaIdInfo
817 tcIdInfo name ty DiscardedInfo = return vanillaIdInfo
818 tcIdInfo name ty (HasInfo iface_info)
819 = foldlM tcPrag init_info iface_info
821 -- Set the CgInfo to something sensible but uninformative before
822 -- we start; default assumption is that it has CAFs
823 init_info = vanillaIdInfo
825 tcPrag info HsNoCafRefs = returnM (info `setCafInfo` NoCafRefs)
826 tcPrag info (HsArity arity) = returnM (info `setArityInfo` arity)
827 tcPrag info (HsStrictness str) = returnM (info `setAllStrictnessInfo` Just str)
829 -- The next two are lazy, so they don't transitively suck stuff in
830 tcPrag info (HsWorker nm arity) = tcWorkerInfo ty info nm arity
831 tcPrag info (HsUnfold inline_prag expr)
832 = tcPragExpr name expr `thenM` \ maybe_expr' ->
834 -- maybe_expr' doesn't get looked at if the unfolding
835 -- is never inspected; so the typecheck doesn't even happen
836 unfold_info = case maybe_expr' of
837 Nothing -> noUnfolding
838 Just expr' -> mkTopUnfolding expr'
840 returnM (info `setUnfoldingInfoLazily` unfold_info
841 `setInlinePragInfo` inline_prag)
845 tcWorkerInfo ty info wkr_name arity
846 = do { mb_wkr_id <- forkM_maybe doc (tcIfaceExtId (LocalTop wkr_name))
848 -- We return without testing maybe_wkr_id, but as soon as info is
849 -- looked at we will test it. That's ok, because its outside the
850 -- knot; and there seems no big reason to further defer the
851 -- tcIfaceId lookup. (Contrast with tcPragExpr, where postponing walking
852 -- over the unfolding until it's actually used does seem worth while.)
853 ; us <- newUniqueSupply
855 ; returnM (case mb_wkr_id of
857 Just wkr_id -> add_wkr_info us wkr_id info) }
859 doc = text "Worker for" <+> ppr wkr_name
860 add_wkr_info us wkr_id info
861 = info `setUnfoldingInfoLazily` mk_unfolding us wkr_id
862 `setWorkerInfo` HasWorker wkr_id arity
864 mk_unfolding us wkr_id = mkTopUnfolding (initUs_ us (mkWrapper ty strict_sig) wkr_id)
866 -- We are relying here on strictness info always appearing
867 -- before worker info, fingers crossed ....
868 strict_sig = case newStrictnessInfo info of
870 Nothing -> pprPanic "Worker info but no strictness for" (ppr wkr_name)
873 For unfoldings we try to do the job lazily, so that we never type check
874 an unfolding that isn't going to be looked at.
877 tcPragExpr :: Name -> IfaceExpr -> IfL (Maybe CoreExpr)
880 tcIfaceExpr expr `thenM` \ core_expr' ->
882 -- Check for type consistency in the unfolding
883 ifOptM Opt_DoCoreLinting (
884 get_in_scope_ids `thenM` \ in_scope ->
885 case lintUnfolding noSrcLoc in_scope core_expr' of
886 Nothing -> returnM ()
887 Just fail_msg -> pprPanic "Iface Lint failure" (doc <+> fail_msg)
892 doc = text "Unfolding of" <+> ppr name
893 get_in_scope_ids -- Urgh; but just for linting
895 do { env <- getGblEnv
896 ; case if_rec_types env of {
897 Nothing -> return [] ;
898 Just (_, get_env) -> do
899 { type_env <- get_env
900 ; return (typeEnvIds type_env) }}}
905 %************************************************************************
909 %************************************************************************
912 bindIfaceBndr :: IfaceBndr -> (CoreBndr -> IfL a) -> IfL a
913 bindIfaceBndr (IfaceIdBndr bndr) thing_inside
914 = bindIfaceId bndr thing_inside
915 bindIfaceBndr (IfaceTvBndr bndr) thing_inside
916 = bindIfaceTyVar bndr thing_inside
918 bindIfaceBndrs :: [IfaceBndr] -> ([CoreBndr] -> IfL a) -> IfL a
919 bindIfaceBndrs [] thing_inside = thing_inside []
920 bindIfaceBndrs (b:bs) thing_inside
921 = bindIfaceBndr b $ \ b' ->
922 bindIfaceBndrs bs $ \ bs' ->
923 thing_inside (b':bs')
925 -----------------------
926 bindIfaceId :: (OccName, IfaceType) -> (Id -> IfL a) -> IfL a
927 bindIfaceId (occ, ty) thing_inside
928 = do { name <- newIfaceName occ
929 ; ty' <- tcIfaceType ty
930 ; let { id = mkLocalId name ty' }
931 ; extendIfaceIdEnv [id] (thing_inside id) }
933 bindIfaceIds :: [(OccName, IfaceType)] -> ([Id] -> IfL a) -> IfL a
934 bindIfaceIds bndrs thing_inside
935 = do { names <- newIfaceNames occs
936 ; tys' <- mappM tcIfaceType tys
937 ; let { ids = zipWithEqual "tcCoreValBndr" mkLocalId names tys' }
938 ; extendIfaceIdEnv ids (thing_inside ids) }
940 (occs,tys) = unzip bndrs
943 -----------------------
944 newExtCoreBndr :: Module -> (OccName, IfaceType) -> IfL Id
945 newExtCoreBndr mod (occ, ty)
946 = do { name <- newGlobalBinder mod occ Nothing noSrcLoc
947 ; ty' <- tcIfaceType ty
948 ; return (mkLocalId name ty') }
950 -----------------------
951 bindIfaceTyVar :: IfaceTvBndr -> (TyVar -> IfL a) -> IfL a
952 bindIfaceTyVar (occ,kind) thing_inside
953 = do { name <- newIfaceName occ
954 ; let tyvar = mk_iface_tyvar name kind
955 ; extendIfaceTyVarEnv [tyvar] (thing_inside tyvar) }
957 bindIfaceTyVars :: [IfaceTvBndr] -> ([TyVar] -> IfL a) -> IfL a
958 bindIfaceTyVars bndrs thing_inside
959 = do { names <- newIfaceNames occs
960 ; let tyvars = zipWith mk_iface_tyvar names kinds
961 ; extendIfaceTyVarEnv tyvars (thing_inside tyvars) }
963 (occs,kinds) = unzip bndrs
965 mk_iface_tyvar name kind = mkTyVar name kind