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 Name ( isLocallyDefined, isWiredInName, nameRdrName, nameModule,
49 import OccName ( OccName, pprOccName, moduleString, pprModule, pprModuleBoot )
50 import TyCon ( TyCon, getSynTyConDefn, isSynTyCon, isNewTyCon, isAlgTyCon,
51 tyConTheta, tyConTyVars, tyConDataCons
53 import Class ( Class, classBigSig )
54 import SpecEnv ( specEnvToList )
55 import FieldLabel ( fieldLabelName, fieldLabelType )
56 import Type ( mkSigmaTy, splitSigmaTy, mkDictTy, tidyTopType, deNoteType,
61 import PprCore ( pprIfaceUnfolding )
63 import Bag ( bagToList, isEmptyBag )
64 import Maybes ( catMaybes, maybeToBool )
65 import FiniteMap ( emptyFM, addToFM, addToFM_C, fmToList, FiniteMap )
66 import UniqFM ( lookupUFM, listToUFM )
67 import UniqSet ( uniqSetToList )
68 import Util ( sortLt, mapAccumL )
72 We have a function @startIface@ to open the output file and put
73 (something like) ``interface Foo'' in it. It gives back a handle
74 for subsequent additions to the interface file.
76 We then have one-function-per-block-of-interface-stuff, e.g.,
77 @ifaceExportList@ produces the @__exports__@ section; it appends
78 to the handle provided by @startIface@.
82 -> IO (Maybe Handle) -- Nothing <=> don't do an interface
84 ifaceMain :: Maybe Handle
89 ifaceDecls :: Maybe Handle
92 -> [Id] -- Ids used at code-gen time; they have better pragma info!
93 -> [CoreBind] -- In dependency order, later depend on earlier
96 endIface :: Maybe Handle -> IO ()
101 = case opt_ProduceHi of
102 Nothing -> return Nothing -- not producing any .hi file
104 if_hdl <- openFile fn WriteMode
105 hPutStr if_hdl ("__interface " ++ moduleString mod ++ ' ':show (opt_HiVersion :: Int))
106 hPutStrLn if_hdl " where"
109 endIface Nothing = return ()
110 endIface (Just if_hdl) = hPutStr if_hdl "\n" >> hClose if_hdl
115 ifaceMain Nothing iface_stuff = return ()
116 ifaceMain (Just if_hdl)
117 (import_usages, ExportEnv avails fixities, instance_modules)
119 ifaceImports if_hdl import_usages
120 ifaceInstanceModules if_hdl instance_modules
121 ifaceExports if_hdl avails
122 ifaceFixities if_hdl fixities
125 ifaceDecls Nothing tycons classes inst_info final_ids simplified = return ()
126 ifaceDecls (Just hdl)
130 | null_decls = return ()
131 -- You could have a module with just (re-)exports/instances in it
133 = ifaceClasses hdl classes >>
134 ifaceInstances hdl inst_infos >>= \ needed_ids ->
135 ifaceTyCons hdl tycons >>
136 ifaceBinds hdl needed_ids final_ids binds >>
139 null_decls = null binds &&
142 isEmptyBag inst_infos
146 ifaceImports if_hdl import_usages
147 = hPutCol if_hdl upp_uses (sortLt lt_imp_vers import_usages)
149 upp_uses (m, mv, whats_imported)
150 = ptext SLIT("import ") <>
151 hsep [pprModule m, pprModuleBoot m, int mv, dcolon,
152 upp_import_versions whats_imported
155 -- Importing the whole module is indicated by an empty list
156 upp_import_versions Everything = empty
158 -- For imported versions we do print the version number
159 upp_import_versions (Specifically nvs)
160 = hsep [ hsep [ppr_unqual_name n, int v] | (n,v) <- sort_versions nvs ]
162 ifaceInstanceModules if_hdl [] = return ()
163 ifaceInstanceModules if_hdl imods
164 = let sorted = sortLt (<) imods
165 lines = map (\m -> ptext SLIT("__instimport ") <> pprModule m <>
166 ptext SLIT(" ;")) sorted
168 printForIface if_hdl (vcat lines) >>
171 ifaceExports if_hdl [] = return ()
172 ifaceExports if_hdl avails
173 = hPutCol if_hdl do_one_module (fmToList export_fm)
175 -- Sort them into groups by module
176 export_fm :: FiniteMap Module [AvailInfo]
177 export_fm = foldr insert emptyFM avails
179 insert avail efm = addToFM_C (++) efm mod [avail]
181 mod = nameModule (availName avail)
183 -- Print one module's worth of stuff
184 do_one_module :: (Module, [AvailInfo]) -> SDoc
185 do_one_module (mod_name, avails@(avail1:_))
186 = ptext SLIT("__export ") <>
187 hsep [pprModuleBoot (nameModule (availName avail1)),
189 hsep (map upp_avail (sortLt lt_avail avails))
192 ifaceFixities if_hdl [] = return ()
193 ifaceFixities if_hdl fixities
194 = hPutCol if_hdl upp_fixity fixities
197 %************************************************************************
199 \subsection{Instance declarations}
201 %************************************************************************
205 ifaceInstances :: Handle -> Bag InstInfo -> IO IdSet -- The IdSet is the needed dfuns
206 ifaceInstances if_hdl inst_infos
207 | null togo_insts = return emptyVarSet
208 | otherwise = hPutCol if_hdl pp_inst (sortLt lt_inst togo_insts) >>
211 togo_insts = filter is_togo_inst (bagToList inst_infos)
212 needed_ids = mkVarSet [dfun_id | InstInfo _ _ _ _ dfun_id _ _ _ <- togo_insts]
213 is_togo_inst (InstInfo _ _ _ _ dfun_id _ _ _) = isLocallyDefined dfun_id
216 lt_inst (InstInfo _ _ _ _ dfun_id1 _ _ _)
217 (InstInfo _ _ _ _ dfun_id2 _ _ _)
218 = getOccName dfun_id1 < getOccName dfun_id2
219 -- The dfuns are assigned names df1, df2, etc, in order of original textual
220 -- occurrence, and this makes as good a sort order as any
223 pp_inst (InstInfo clas tvs tys theta dfun_id _ _ _)
225 -- The deNoteType is very important. It removes all type
226 -- synonyms from the instance type in interface files.
227 -- That in turn makes sure that when reading in instance decls
228 -- from interface files that the 'gating' mechanism works properly.
229 -- Otherwise you could have
230 -- type Tibble = T Int
231 -- instance Foo Tibble where ...
232 -- and this instance decl wouldn't get imported into a module
233 -- that mentioned T but not Tibble.
234 forall_ty = mkSigmaTy tvs theta (deNoteType (mkDictTy clas tys))
235 renumbered_ty = tidyTopType forall_ty
237 hcat [ptext SLIT("instance "), pprType renumbered_ty,
238 ptext SLIT(" = "), ppr_unqual_name dfun_id, semi]
242 %************************************************************************
244 \subsection{Printing values}
246 %************************************************************************
249 ifaceId :: (Id -> IdInfo) -- This function "knows" the extra info added
250 -- by the STG passes. Sigh
252 -> IdSet -- Set of Ids that are needed by earlier interface
253 -- file emissions. If the Id isn't in this set, and isn't
254 -- exported, there's no need to emit anything
255 -> Bool -- True <=> recursive, so don't print unfolding
257 -> CoreExpr -- The Id's right hand side
258 -> Maybe (SDoc, IdSet) -- The emitted stuff, plus a possibly-augmented set of needed Ids
260 ifaceId get_idinfo needed_ids is_rec id rhs
261 | not (id `elemVarSet` needed_ids || -- Needed [no id in needed_ids has omitIfaceSigForId]
262 (isExported id && not (omitIfaceSigForId id))) -- or exported and not to be omitted
263 = Nothing -- Well, that was easy!
265 ifaceId get_idinfo needed_ids is_rec id rhs
266 = Just (hsep [sig_pretty, prag_pretty, char ';'], new_needed_ids)
268 idinfo = get_idinfo id
269 inline_pragma = inlinePragInfo idinfo
271 ty_pretty = pprType (idType id)
272 sig_pretty = hsep [ppr (getOccName id), dcolon, ty_pretty]
275 | opt_OmitInterfacePragmas = empty
276 | otherwise = hsep [ptext SLIT("{-##"),
284 ------------ Arity --------------
285 arity_pretty = ppArityInfo (arityInfo idinfo)
287 ------------ Caf Info --------------
288 caf_pretty = ppCafInfo (cafInfo idinfo)
290 ------------ Strictness --------------
291 strict_info = strictnessInfo idinfo
292 has_worker = workerExists strict_info
293 bottoming_fn = isBottomingStrictness strict_info
294 strict_pretty = ppStrictnessInfo strict_info <+> wrkr_pretty
296 wrkr_pretty | not has_worker = empty
297 | null con_list = ppr work_id
298 | otherwise = ppr work_id <+>
299 braces (hsep (map ppr con_list))
301 (work_id, wrapper_cons) = getWorkerIdAndCons id rhs
302 con_list = uniqSetToList wrapper_cons
304 ------------ Unfolding --------------
305 unfold_pretty | show_unfold = unfold_herald <+> pprIfaceUnfolding rhs
308 show_unfold = not has_worker && -- Not unnecessary
309 not bottoming_fn && -- Not necessary
310 unfolding_needed -- Not dangerous
312 unfolding_needed = case inline_pragma of
313 IMustBeINLINEd -> definitely_ok_to_unfold
314 IWantToBeINLINEd -> definitely_ok_to_unfold
315 NoInlinePragInfo -> rhs_is_small
319 unfold_herald = case inline_pragma of
320 NoInlinePragInfo -> ptext SLIT("__u")
321 other -> ppr inline_pragma
323 rhs_is_small = case calcUnfoldingGuidance opt_InterfaceUnfoldThreshold rhs of
324 UnfoldNever -> False -- Too big
325 other -> definitely_ok_to_unfold -- Small enough
327 definitely_ok_to_unfold = okToUnfoldInHiFile rhs
329 ------------ Specialisations --------------
330 spec_list = specEnvToList (getIdSpecialisation id)
331 spec_pretty = hsep (map pp_spec spec_list)
332 pp_spec (tyvars, tys, rhs) = hsep [ptext SLIT("__P"),
333 if null tyvars then ptext SLIT("[ ]")
334 else brackets (interppSP tyvars),
335 -- The lexer interprets "[]" as a CONID. Sigh.
336 hsep (map pprParendType tys),
338 pprIfaceUnfolding rhs
341 ------------ Extra free Ids --------------
342 new_needed_ids = (needed_ids `minusVarSet` unitVarSet id) `unionVarSet`
345 extra_ids | opt_OmitInterfacePragmas = emptyVarSet
346 | otherwise = worker_ids `unionVarSet`
347 unfold_ids `unionVarSet`
350 worker_ids | has_worker && interesting work_id = unitVarSet work_id
351 -- Conceivably, the worker might come from
353 | otherwise = emptyVarSet
355 spec_ids = foldr add emptyVarSet spec_list
357 add (_, _, rhs) = unionVarSet (find_fvs rhs)
359 unfold_ids | show_unfold = find_fvs rhs
360 | otherwise = emptyVarSet
362 find_fvs expr = free_vars
364 free_vars = exprSomeFreeVars interesting expr
366 interesting id = isId id && isLocallyDefined id &&
367 not (omitIfaceSigForId id)
372 -> IdSet -- These Ids are needed already
373 -> [Id] -- Ids used at code-gen time; they have better pragma info!
374 -> [CoreBind] -- In dependency order, later depend on earlier
377 ifaceBinds hdl needed_ids final_ids binds
378 = mapIO (printForIface hdl) pretties >>
381 final_id_map = listToUFM [(id,id) | id <- final_ids]
382 get_idinfo id = case lookupUFM final_id_map id of
383 Just id' -> idInfo id'
384 Nothing -> pprTrace "ifaceBinds not found:" (ppr id) $
387 pretties = go needed_ids (reverse binds) -- Reverse so that later things will
388 -- provoke earlier ones to be emitted
389 go needed [] = if not (isEmptyVarSet needed) then
390 pprTrace "ifaceBinds: free vars:"
391 (sep (map ppr (varSetElems needed))) $
396 go needed (NonRec id rhs : binds)
397 = case ifaceId get_idinfo needed False id rhs of
398 Nothing -> go needed binds
399 Just (pretty, needed') -> pretty : go needed' binds
401 -- Recursive groups are a bit more of a pain. We may only need one to
402 -- start with, but it may call out the next one, and so on. So we
403 -- have to look for a fixed point.
404 go needed (Rec pairs : binds)
405 = pretties ++ go needed'' binds
407 (needed', pretties) = go_rec needed pairs
408 needed'' = needed' `minusVarSet` mkVarSet (map fst pairs)
409 -- Later ones may spuriously cause earlier ones to be "needed" again
411 go_rec :: IdSet -> [(Id,CoreExpr)] -> (IdSet, [SDoc])
413 | null pretties = (needed, [])
414 | otherwise = (final_needed, more_pretties ++ pretties)
416 reduced_pairs = [pair | (pair,Nothing) <- pairs `zip` maybes]
417 pretties = catMaybes maybes
418 (needed', maybes) = mapAccumL do_one needed pairs
419 (final_needed, more_pretties) = go_rec needed' reduced_pairs
421 do_one needed (id,rhs) = case ifaceId get_idinfo needed True id rhs of
422 Nothing -> (needed, Nothing)
423 Just (pretty, needed') -> (needed', Just pretty)
427 %************************************************************************
429 \subsection{Random small things}
431 %************************************************************************
434 ifaceTyCons hdl tycons = hPutCol hdl upp_tycon (sortLt (<) (filter (for_iface_name . getName) tycons ))
435 ifaceClasses hdl classes = hPutCol hdl upp_class (sortLt (<) (filter (for_iface_name . getName) classes))
437 for_iface_name name = isLocallyDefined name &&
438 not (isWiredInName name)
440 upp_tycon tycon = ifaceTyCon tycon
441 upp_class clas = ifaceClass clas
446 ifaceTyCon :: TyCon -> SDoc
449 = hsep [ ptext SLIT("type"),
451 pprTyVarBndrs tyvars,
457 (tyvars, ty) = getSynTyConDefn tycon
461 = hsep [ ptext keyword,
462 ppr_decl_context (tyConTheta tycon),
464 pprTyVarBndrs (tyConTyVars tycon),
466 hsep (punctuate (ptext SLIT(" | ")) (map ppr_con (tyConDataCons tycon))),
470 keyword | isNewTyCon tycon = SLIT("newtype")
471 | otherwise = SLIT("data")
473 tyvars = tyConTyVars tycon
477 = ASSERT( tycon == tycon1 && tyvars == tyvars1 )
478 hsep [ ppr_ex ex_tyvars ex_theta,
480 hsep (map ppr_arg_ty (strict_marks `zip` arg_tys))
484 = hsep [ ppr_ex ex_tyvars ex_theta,
486 braces $ hsep $ punctuate comma (map ppr_field (strict_marks `zip` field_labels))
489 (tyvars1, theta1, ex_tyvars, ex_theta, arg_tys, tycon1) = dataConSig data_con
490 field_labels = dataConFieldLabels data_con
491 strict_marks = dataConStrictMarks data_con
492 name = getName data_con
494 ppr_ex [] ex_theta = ASSERT( null ex_theta ) empty
495 ppr_ex ex_tvs ex_theta = ptext SLIT("__forall") <+> brackets (pprTyVarBndrs ex_tvs)
496 <+> pprIfaceTheta ex_theta <+> ptext SLIT("=>")
498 ppr_arg_ty (strict_mark, ty) = ppr_strict_mark strict_mark <> pprParendType ty
500 ppr_strict_mark NotMarkedStrict = empty
501 ppr_strict_mark MarkedStrict = ptext SLIT("! ")
502 -- The extra space helps the lexical analyser that lexes
503 -- interface files; it doesn't make the rigid operator/identifier
504 -- distinction, so "!a" is a valid identifier so far as it is concerned
506 ppr_field (strict_mark, field_label)
507 = hsep [ ppr (fieldLabelName field_label),
509 ppr_strict_mark strict_mark <> pprParendType (fieldLabelType field_label)
513 = pprPanic "pprIfaceTyDecl" (ppr tycon)
516 = hsep [ptext SLIT("class"),
517 ppr_decl_context sc_theta,
518 ppr clas, -- Print the name
519 pprTyVarBndrs clas_tyvars,
524 (clas_tyvars, sc_theta, _, sel_ids, defms) = classBigSig clas
526 pp_ops | null sel_ids = empty
527 | otherwise = hsep [ptext SLIT("where"),
528 braces (hsep (punctuate semi (zipWith ppr_classop sel_ids defms)))
531 ppr_classop sel_id maybe_defm
532 = ASSERT( sel_tyvars == clas_tyvars)
533 hsep [ppr (getOccName sel_id),
534 if maybeToBool maybe_defm then equals else empty,
539 (sel_tyvars, _, op_ty) = splitSigmaTy (idType sel_id)
541 ppr_decl_context :: ThetaType -> SDoc
542 ppr_decl_context [] = empty
543 ppr_decl_context theta = pprIfaceTheta theta <+> ptext SLIT(" =>")
545 pprIfaceTheta :: ThetaType -> SDoc -- Use braces rather than parens in interface files
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