2 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
4 \section[MkIface]{Print an interface for a module}
13 #include "HsVersions.h"
15 import IO ( Handle, hPutStr, openFile,
16 hClose, hPutStrLn, IOMode(..) )
19 import BasicTypes ( Fixity(..), FixityDirection(..), NewOrData(..),
23 import RnEnv ( availName )
25 import TcInstUtil ( InstInfo(..) )
26 import WorkWrap ( getWorkerIdAndCons )
29 import Id ( Id, idType, idInfo, omitIfaceSigForId,
34 import DataCon ( dataConSig, dataConFieldLabels, dataConStrictMarks )
35 import IdInfo ( IdInfo, StrictnessInfo, ArityInfo, InlinePragInfo(..), inlinePragInfo,
36 arityInfo, ppArityInfo,
37 strictnessInfo, ppStrictnessInfo,
39 workerExists, isBottomingStrictness
41 import CoreSyn ( CoreExpr, CoreBind, Bind(..) )
42 import CoreUtils ( exprSomeFreeVars )
43 import CoreUnfold ( calcUnfoldingGuidance, UnfoldingGuidance(..),
44 Unfolding, okToUnfoldInHiFile )
45 import Module ( moduleString, pprModule, pprModuleBoot )
46 import Name ( isLocallyDefined, isWiredInName, nameRdrName, nameModule,
50 import OccName ( OccName, pprOccName )
51 import TyCon ( TyCon, getSynTyConDefn, isSynTyCon, isNewTyCon, isAlgTyCon,
52 tyConTheta, tyConTyVars, tyConDataCons
54 import Class ( Class, classBigSig )
55 import SpecEnv ( specEnvToList )
56 import FieldLabel ( fieldLabelName, fieldLabelType )
57 import Type ( mkSigmaTy, splitSigmaTy, mkDictTy, tidyTopType, deNoteType,
62 import PprCore ( pprIfaceUnfolding )
64 import Bag ( bagToList, isEmptyBag )
65 import Maybes ( catMaybes, maybeToBool )
66 import FiniteMap ( emptyFM, addToFM, addToFM_C, fmToList, FiniteMap )
67 import UniqFM ( lookupUFM, listToUFM )
68 import UniqSet ( uniqSetToList )
69 import Util ( sortLt, mapAccumL )
73 We have a function @startIface@ to open the output file and put
74 (something like) ``interface Foo'' in it. It gives back a handle
75 for subsequent additions to the interface file.
77 We then have one-function-per-block-of-interface-stuff, e.g.,
78 @ifaceExportList@ produces the @__exports__@ section; it appends
79 to the handle provided by @startIface@.
83 -> IO (Maybe Handle) -- Nothing <=> don't do an interface
85 ifaceMain :: Maybe Handle
90 ifaceDecls :: Maybe Handle
93 -> [Id] -- Ids used at code-gen time; they have better pragma info!
94 -> [CoreBind] -- In dependency order, later depend on earlier
97 endIface :: Maybe Handle -> IO ()
102 = case opt_ProduceHi of
103 Nothing -> return Nothing -- not producing any .hi file
105 if_hdl <- openFile fn WriteMode
106 hPutStr if_hdl ("__interface " ++ moduleString mod ++ ' ':show (opt_HiVersion :: Int))
107 hPutStrLn if_hdl " where"
110 endIface Nothing = return ()
111 endIface (Just if_hdl) = hPutStr if_hdl "\n" >> hClose if_hdl
116 ifaceMain Nothing iface_stuff = return ()
117 ifaceMain (Just if_hdl)
118 (import_usages, ExportEnv avails fixities, instance_modules)
120 ifaceImports if_hdl import_usages
121 ifaceInstanceModules if_hdl instance_modules
122 ifaceExports if_hdl avails
123 ifaceFixities if_hdl fixities
126 ifaceDecls Nothing tycons classes inst_info final_ids simplified = return ()
127 ifaceDecls (Just hdl)
131 | null_decls = return ()
132 -- You could have a module with just (re-)exports/instances in it
134 = ifaceClasses hdl classes >>
135 ifaceInstances hdl inst_infos >>= \ needed_ids ->
136 ifaceTyCons hdl tycons >>
137 ifaceBinds hdl needed_ids final_ids binds >>
140 null_decls = null binds &&
143 isEmptyBag inst_infos
147 ifaceImports if_hdl import_usages
148 = hPutCol if_hdl upp_uses (sortLt lt_imp_vers import_usages)
150 upp_uses (m, mv, whats_imported)
151 = ptext SLIT("import ") <>
152 hsep [pprModule m, pprModuleBoot m, int mv, dcolon,
153 upp_import_versions whats_imported
156 -- Importing the whole module is indicated by an empty list
157 upp_import_versions Everything = empty
159 -- For imported versions we do print the version number
160 upp_import_versions (Specifically nvs)
161 = hsep [ hsep [ppr_unqual_name n, int v] | (n,v) <- sort_versions nvs ]
163 ifaceInstanceModules if_hdl [] = return ()
164 ifaceInstanceModules if_hdl imods
165 = let sorted = sortLt (<) imods
166 lines = map (\m -> ptext SLIT("__instimport ") <> pprModule m <>
167 ptext SLIT(" ;")) sorted
169 printForIface if_hdl (vcat lines) >>
172 ifaceExports if_hdl [] = return ()
173 ifaceExports if_hdl avails
174 = hPutCol if_hdl do_one_module (fmToList export_fm)
176 -- Sort them into groups by module
177 export_fm :: FiniteMap Module [AvailInfo]
178 export_fm = foldr insert emptyFM avails
180 insert avail efm = addToFM_C (++) efm mod [avail]
182 mod = nameModule (availName avail)
184 -- Print one module's worth of stuff
185 do_one_module :: (Module, [AvailInfo]) -> SDoc
186 do_one_module (mod_name, avails@(avail1:_))
187 = ptext SLIT("__export ") <>
188 hsep [pprModuleBoot (nameModule (availName avail1)),
190 hsep (map upp_avail (sortLt lt_avail avails))
193 ifaceFixities if_hdl [] = return ()
194 ifaceFixities if_hdl fixities
195 = hPutCol if_hdl upp_fixity fixities
198 %************************************************************************
200 \subsection{Instance declarations}
202 %************************************************************************
206 ifaceInstances :: Handle -> Bag InstInfo -> IO IdSet -- The IdSet is the needed dfuns
207 ifaceInstances if_hdl inst_infos
208 | null togo_insts = return emptyVarSet
209 | otherwise = hPutCol if_hdl pp_inst (sortLt lt_inst togo_insts) >>
212 togo_insts = filter is_togo_inst (bagToList inst_infos)
213 needed_ids = mkVarSet [dfun_id | InstInfo _ _ _ _ dfun_id _ _ _ <- togo_insts]
214 is_togo_inst (InstInfo _ _ _ _ dfun_id _ _ _) = isLocallyDefined dfun_id
217 lt_inst (InstInfo _ _ _ _ dfun_id1 _ _ _)
218 (InstInfo _ _ _ _ dfun_id2 _ _ _)
219 = getOccName dfun_id1 < getOccName dfun_id2
220 -- The dfuns are assigned names df1, df2, etc, in order of original textual
221 -- occurrence, and this makes as good a sort order as any
224 pp_inst (InstInfo clas tvs tys theta dfun_id _ _ _)
226 -- The deNoteType is very important. It removes all type
227 -- synonyms from the instance type in interface files.
228 -- That in turn makes sure that when reading in instance decls
229 -- from interface files that the 'gating' mechanism works properly.
230 -- Otherwise you could have
231 -- type Tibble = T Int
232 -- instance Foo Tibble where ...
233 -- and this instance decl wouldn't get imported into a module
234 -- that mentioned T but not Tibble.
235 forall_ty = mkSigmaTy tvs theta (deNoteType (mkDictTy clas tys))
236 renumbered_ty = tidyTopType forall_ty
238 hcat [ptext SLIT("instance "), pprType renumbered_ty,
239 ptext SLIT(" = "), ppr_unqual_name dfun_id, semi]
243 %************************************************************************
245 \subsection{Printing values}
247 %************************************************************************
250 ifaceId :: (Id -> IdInfo) -- This function "knows" the extra info added
251 -- by the STG passes. Sigh
253 -> IdSet -- Set of Ids that are needed by earlier interface
254 -- file emissions. If the Id isn't in this set, and isn't
255 -- exported, there's no need to emit anything
256 -> Bool -- True <=> recursive, so don't print unfolding
258 -> CoreExpr -- The Id's right hand side
259 -> Maybe (SDoc, IdSet) -- The emitted stuff, plus a possibly-augmented set of needed Ids
261 ifaceId get_idinfo needed_ids is_rec id rhs
262 | not (id `elemVarSet` needed_ids || -- Needed [no id in needed_ids has omitIfaceSigForId]
263 (isExported id && not (omitIfaceSigForId id))) -- or exported and not to be omitted
264 = Nothing -- Well, that was easy!
266 ifaceId get_idinfo needed_ids is_rec id rhs
267 = Just (hsep [sig_pretty, prag_pretty, char ';'], new_needed_ids)
269 idinfo = get_idinfo id
270 inline_pragma = inlinePragInfo idinfo
272 ty_pretty = pprType (idType id)
273 sig_pretty = hsep [ppr (getOccName id), dcolon, ty_pretty]
276 | opt_OmitInterfacePragmas = empty
277 | otherwise = hsep [ptext SLIT("{-##"),
285 ------------ Arity --------------
286 arity_pretty = ppArityInfo (arityInfo idinfo)
288 ------------ Caf Info --------------
289 caf_pretty = ppCafInfo (cafInfo idinfo)
291 ------------ Strictness --------------
292 strict_info = strictnessInfo idinfo
293 has_worker = workerExists strict_info
294 bottoming_fn = isBottomingStrictness strict_info
295 strict_pretty = ppStrictnessInfo strict_info <+> wrkr_pretty
297 wrkr_pretty | not has_worker = empty
298 | null con_list = ppr work_id
299 | otherwise = ppr work_id <+>
300 braces (hsep (map ppr con_list))
302 (work_id, wrapper_cons) = getWorkerIdAndCons id rhs
303 con_list = uniqSetToList wrapper_cons
305 ------------ Unfolding --------------
306 unfold_pretty | show_unfold = unfold_herald <+> pprIfaceUnfolding rhs
309 show_unfold = not has_worker && -- Not unnecessary
310 not bottoming_fn && -- Not necessary
311 unfolding_needed -- Not dangerous
313 unfolding_needed = case inline_pragma of
314 IMustBeINLINEd -> definitely_ok_to_unfold
315 IWantToBeINLINEd -> definitely_ok_to_unfold
316 NoInlinePragInfo -> rhs_is_small
320 unfold_herald = case inline_pragma of
321 NoInlinePragInfo -> ptext SLIT("__u")
322 other -> ppr inline_pragma
324 rhs_is_small = case calcUnfoldingGuidance opt_InterfaceUnfoldThreshold rhs of
325 UnfoldNever -> False -- Too big
326 other -> definitely_ok_to_unfold -- Small enough
328 definitely_ok_to_unfold = okToUnfoldInHiFile rhs
330 ------------ Specialisations --------------
331 spec_list = specEnvToList (getIdSpecialisation id)
332 spec_pretty = hsep (map pp_spec spec_list)
333 pp_spec (tyvars, tys, rhs) = hsep [ptext SLIT("__P"),
334 if null tyvars then ptext SLIT("[ ]")
335 else brackets (interppSP tyvars),
336 -- The lexer interprets "[]" as a CONID. Sigh.
337 hsep (map pprParendType tys),
339 pprIfaceUnfolding rhs
342 ------------ Extra free Ids --------------
343 new_needed_ids = (needed_ids `minusVarSet` unitVarSet id) `unionVarSet`
346 extra_ids | opt_OmitInterfacePragmas = emptyVarSet
347 | otherwise = worker_ids `unionVarSet`
348 unfold_ids `unionVarSet`
351 worker_ids | has_worker && interesting work_id = unitVarSet work_id
352 -- Conceivably, the worker might come from
354 | otherwise = emptyVarSet
356 spec_ids = foldr add emptyVarSet spec_list
358 add (_, _, rhs) = unionVarSet (find_fvs rhs)
360 unfold_ids | show_unfold = find_fvs rhs
361 | otherwise = emptyVarSet
363 find_fvs expr = free_vars
365 free_vars = exprSomeFreeVars interesting expr
367 interesting id = isId id && isLocallyDefined id &&
368 not (omitIfaceSigForId id)
373 -> IdSet -- These Ids are needed already
374 -> [Id] -- Ids used at code-gen time; they have better pragma info!
375 -> [CoreBind] -- In dependency order, later depend on earlier
378 ifaceBinds hdl needed_ids final_ids binds
379 = mapIO (printForIface hdl) pretties >>
382 final_id_map = listToUFM [(id,id) | id <- final_ids]
383 get_idinfo id = case lookupUFM final_id_map id of
384 Just id' -> idInfo id'
385 Nothing -> pprTrace "ifaceBinds not found:" (ppr id) $
388 pretties = go needed_ids (reverse binds) -- Reverse so that later things will
389 -- provoke earlier ones to be emitted
390 go needed [] = if not (isEmptyVarSet needed) then
391 pprTrace "ifaceBinds: free vars:"
392 (sep (map ppr (varSetElems needed))) $
397 go needed (NonRec id rhs : binds)
398 = case ifaceId get_idinfo needed False id rhs of
399 Nothing -> go needed binds
400 Just (pretty, needed') -> pretty : go needed' binds
402 -- Recursive groups are a bit more of a pain. We may only need one to
403 -- start with, but it may call out the next one, and so on. So we
404 -- have to look for a fixed point.
405 go needed (Rec pairs : binds)
406 = pretties ++ go needed'' binds
408 (needed', pretties) = go_rec needed pairs
409 needed'' = needed' `minusVarSet` mkVarSet (map fst pairs)
410 -- Later ones may spuriously cause earlier ones to be "needed" again
412 go_rec :: IdSet -> [(Id,CoreExpr)] -> (IdSet, [SDoc])
414 | null pretties = (needed, [])
415 | otherwise = (final_needed, more_pretties ++ pretties)
417 reduced_pairs = [pair | (pair,Nothing) <- pairs `zip` maybes]
418 pretties = catMaybes maybes
419 (needed', maybes) = mapAccumL do_one needed pairs
420 (final_needed, more_pretties) = go_rec needed' reduced_pairs
422 do_one needed (id,rhs) = case ifaceId get_idinfo needed True id rhs of
423 Nothing -> (needed, Nothing)
424 Just (pretty, needed') -> (needed', Just pretty)
428 %************************************************************************
430 \subsection{Random small things}
432 %************************************************************************
435 ifaceTyCons hdl tycons = hPutCol hdl upp_tycon (sortLt (<) (filter (for_iface_name . getName) tycons ))
436 ifaceClasses hdl classes = hPutCol hdl upp_class (sortLt (<) (filter (for_iface_name . getName) classes))
438 for_iface_name name = isLocallyDefined name &&
439 not (isWiredInName name)
441 upp_tycon tycon = ifaceTyCon tycon
442 upp_class clas = ifaceClass clas
447 ifaceTyCon :: TyCon -> SDoc
450 = hsep [ ptext SLIT("type"),
452 pprTyVarBndrs tyvars,
458 (tyvars, ty) = getSynTyConDefn tycon
462 = hsep [ ptext keyword,
463 ppr_decl_context (tyConTheta tycon),
465 pprTyVarBndrs (tyConTyVars tycon),
467 hsep (punctuate (ptext SLIT(" | ")) (map ppr_con (tyConDataCons tycon))),
471 keyword | isNewTyCon tycon = SLIT("newtype")
472 | otherwise = SLIT("data")
474 tyvars = tyConTyVars tycon
478 = ASSERT( tycon == tycon1 && tyvars == tyvars1 )
479 hsep [ ppr_ex ex_tyvars ex_theta,
481 hsep (map ppr_arg_ty (strict_marks `zip` arg_tys))
485 = hsep [ ppr_ex ex_tyvars ex_theta,
487 braces $ hsep $ punctuate comma (map ppr_field (strict_marks `zip` field_labels))
490 (tyvars1, theta1, ex_tyvars, ex_theta, arg_tys, tycon1) = dataConSig data_con
491 field_labels = dataConFieldLabels data_con
492 strict_marks = dataConStrictMarks data_con
493 name = getName data_con
495 ppr_ex [] ex_theta = ASSERT( null ex_theta ) empty
496 ppr_ex ex_tvs ex_theta = ptext SLIT("__forall") <+> brackets (pprTyVarBndrs ex_tvs)
497 <+> pprIfaceTheta ex_theta <+> ptext SLIT("=>")
499 ppr_arg_ty (strict_mark, ty) = ppr_strict_mark strict_mark <> pprParendType ty
501 ppr_strict_mark NotMarkedStrict = empty
502 ppr_strict_mark (MarkedUnboxed _ _) = ptext SLIT("! ! ")
503 ppr_strict_mark MarkedStrict = ptext SLIT("! ")
505 ppr_field (strict_mark, field_label)
506 = hsep [ ppr (fieldLabelName field_label),
508 ppr_strict_mark strict_mark <> pprParendType (fieldLabelType field_label)
512 = pprPanic "pprIfaceTyDecl" (ppr tycon)
515 = hsep [ptext SLIT("class"),
516 ppr_decl_context sc_theta,
517 ppr clas, -- Print the name
518 pprTyVarBndrs clas_tyvars,
523 (clas_tyvars, sc_theta, _, sel_ids, defms) = classBigSig clas
525 pp_ops | null sel_ids = empty
526 | otherwise = hsep [ptext SLIT("where"),
527 braces (hsep (punctuate semi (zipWith ppr_classop sel_ids defms)))
530 ppr_classop sel_id maybe_defm
531 = ASSERT( sel_tyvars == clas_tyvars)
532 hsep [ppr (getOccName sel_id),
533 if maybeToBool maybe_defm then equals else empty,
538 (sel_tyvars, _, op_ty) = splitSigmaTy (idType sel_id)
540 ppr_decl_context :: ThetaType -> SDoc
541 ppr_decl_context [] = empty
542 ppr_decl_context theta = pprIfaceTheta theta <+> ptext SLIT(" =>")
544 pprIfaceTheta :: ThetaType -> SDoc -- Use braces rather than parens in interface files
545 pprIfaceTheta [] = empty
546 pprIfaceTheta theta = braces (hsep (punctuate comma [pprConstraint c tys | (c,tys) <- theta]))
549 %************************************************************************
551 \subsection{Random small things}
553 %************************************************************************
555 When printing export lists, we print like this:
557 AvailTC C [C, x, y] C(x,y)
558 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
561 upp_avail :: AvailInfo -> SDoc
562 upp_avail (Avail name) = pprOccName (getOccName name)
563 upp_avail (AvailTC name []) = empty
564 upp_avail (AvailTC name ns) = hcat [pprOccName (getOccName name), bang, upp_export ns']
566 bang | name `elem` ns = empty
567 | otherwise = char '|'
568 ns' = filter (/= name) ns
570 upp_export :: [Name] -> SDoc
571 upp_export [] = empty
572 upp_export names = braces (hsep (map (pprOccName . getOccName) names))
574 upp_fixity :: (Name, Fixity) -> SDoc
575 upp_fixity (name, fixity) = hsep [ptext SLIT("0"), ppr fixity, ppr name, semi]
576 -- Dummy version number!
578 ppr_unqual_name :: NamedThing a => a -> SDoc -- Just its occurrence name
579 ppr_unqual_name name = pprOccName (getOccName name)
583 %************************************************************************
585 \subsection{Comparisons
587 %************************************************************************
590 The various sorts above simply prevent unnecessary "wobbling" when
591 things change that don't have to. We therefore compare lexically, not
595 lt_avail :: AvailInfo -> AvailInfo -> Bool
597 a1 `lt_avail` a2 = availName a1 `lt_name` availName a2
599 lt_name :: Name -> Name -> Bool
600 n1 `lt_name` n2 = nameRdrName n1 < nameRdrName n2
602 lt_lexical :: NamedThing a => a -> a -> Bool
603 lt_lexical a1 a2 = getName a1 `lt_name` getName a2
605 lt_imp_vers :: ImportVersion a -> ImportVersion a -> Bool
606 lt_imp_vers (m1,_,_) (m2,_,_) = m1 < m2
608 sort_versions vs = sortLt lt_vers vs
610 lt_vers :: LocalVersion Name -> LocalVersion Name -> Bool
611 lt_vers (n1,v1) (n2,v2) = n1 `lt_name` n2
620 hPutCol hdl fmt xs = mapIO (printForIface hdl . fmt) xs
622 mapIO :: (a -> IO b) -> [a] -> IO ()
623 mapIO f [] = return ()
624 mapIO f (x:xs) = f x >> mapIO f xs