2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
8 mkUsageInfo, -- Construct the usage info for a module
10 mkIface, -- Build a ModIface from a ModGuts,
11 -- including computing version information
13 writeIfaceFile, -- Write the interface file
15 checkOldIface, -- See if recompilation is required, by
16 -- comparing version information
18 tyThingToIfaceDecl -- Converting things to their Iface equivalents
22 -----------------------------------------------
23 MkIface.lhs deals with versioning
24 -----------------------------------------------
26 Here's the version-related info in an interface file
28 module Foo 8 -- module-version
29 3 -- export-list-version
31 Usages: -- Version info for what this compilation of Foo imported
32 Baz 3 -- Module version
33 [4] -- The export-list version if Foo depended on it
34 (g,2) -- Function and its version
35 (T,1) -- Type and its version
37 <version> f :: Int -> Int {- Unfolding: \x -> Wib.t[2] x -}
38 -- The [2] says that f's unfolding
39 -- mentions verison 2 of Wib.t
41 -----------------------------------------------
43 -----------------------------------------------
46 * In the mi_usages information in an interface, we record the
47 version number of each free variable of the module
49 * In mkIface, we compute the version number of each exported thing A.f
50 by comparing its A.f's info with its new info, and bumping its
51 version number if it differs. If A.f mentions B.g, and B.g's version
52 number has changed, then we count A.f as having changed too.
54 * In checkOldIface we compare the mi_usages for the module with
55 the actual version info for all each thing recorded in mi_usages
60 We count A.f as changing if its fixity changes
64 If a rule changes, we want to recompile any module that might be
65 affected by that rule. For non-orphan rules, this is relatively easy.
66 If module M defines f, and a rule for f, just arrange that the version
67 number for M.f changes if any of the rules for M.f change. Any module
68 that does not depend on M.f can't be affected by the rule-change
71 Orphan rules (ones whose 'head function' is not defined in M) are
72 harder. Here's what we do.
74 * We have a per-module orphan-rule version number which changes if
75 any orphan rule changes. (It's unaffected by non-orphan rules.)
77 * We record usage info for any orphan module 'below' this one,
78 giving the orphan-rule version number. We recompile if this
81 The net effect is that if an orphan rule changes, we recompile every
82 module above it. That's very conservative, but it's devilishly hard
83 to know what it might affect, so we just have to be conservative.
87 In an iface file we have
89 instance Eq a => Eq [a] = dfun29
92 We have a version number for dfun29, covering its unfolding
93 etc. Suppose we are compiling a module M that imports A only
94 indirectly. If typechecking M uses this instance decl, we record the
95 dependency on A.dfun29 as if it were a free variable of the module
96 (via the tcg_inst_usages accumulator). That means that A will appear
97 in M's usage list. If the shape of the instance declaration changes,
98 then so will dfun29's version, triggering a recompilation.
100 Adding an instance declaration, or changing an instance decl that is
101 not currently used, is more tricky. (This really only makes a
102 difference when we have overlapping instance decls, because then the
103 new instance decl might kick in to override the old one.) We handle
104 this in a very similar way that we handle rules above.
106 * For non-orphan instance decls, identify one locally-defined tycon/class
107 mentioned in the decl. Treat the instance decl as part of the defn of that
108 tycon/class, so that if the shape of the instance decl changes, so does the
109 tycon/class; that in turn will force recompilation of anything that uses
112 * For orphan instance decls, act the same way as for orphan rules.
113 Indeed, we use the same global orphan-rule version number.
117 mkUsageInfo figures out what the ``usage information'' for this
118 moudule is; that is, what it must record in its interface file as the
121 We produce a line for every module B below the module, A, currently being
124 to record the fact that A does import B indirectly. This is used to decide
125 to look to look for B.hi rather than B.hi-boot when compiling a module that
126 imports A. This line says that A imports B, but uses nothing in it.
127 So we'll get an early bale-out when compiling A if B's version changes.
129 The usage information records:
132 \item (a) anything reachable from its body code
133 \item (b) any module exported with a @module Foo@
134 \item (c) anything reachable from an exported item
137 Why (b)? Because if @Foo@ changes then this module's export list
138 will change, so we must recompile this module at least as far as
139 making a new interface file --- but in practice that means complete
142 Why (c)? Consider this:
144 module A( f, g ) where | module B( f ) where
145 import B( f ) | f = h 3
149 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
150 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
151 *identical* to what it was before. If anything about @B.f@ changes
152 than anyone who imports @A@ should be recompiled in case they use
153 @B.f@ (they'll get an early exit if they don't). So, if anything
154 about @B.f@ changes we'd better make sure that something in A.hi
155 changes, and the convenient way to do that is to record the version
156 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
157 complete recompiation of A, which is overkill but it's the only way to
158 write a new, slightly different, A.hi.
160 But the example is tricker. Even if @B.f@ doesn't change at all,
161 @B.h@ may do so, and this change may not be reflected in @f@'s version
162 number. But with -O, a module that imports A must be recompiled if
163 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
164 the occurrence of @B.f@ in the export list *just as if* it were in the
165 code of A, and thereby haul in all the stuff reachable from it.
167 *** Conclusion: if A mentions B.f in its export list,
168 behave just as if A mentioned B.f in its source code,
169 and slurp in B.f and all its transitive closure ***
171 [NB: If B was compiled with -O, but A isn't, we should really *still*
172 haul in all the unfoldings for B, in case the module that imports A *is*
173 compiled with -O. I think this is the case.]
177 #include "HsVersions.h"
210 import PackageConfig hiding ( Version )
212 import BasicTypes hiding ( SuccessFlag(..) )
214 import Util hiding ( eqListBy )
225 %************************************************************************
227 \subsection{Completing an interface}
229 %************************************************************************
233 -> Maybe ModIface -- The old interface, if we have it
234 -> ModGuts -- Usages, deprecations, etc
235 -> ModDetails -- The trimmed, tidied interface
236 -> IO (ModIface, -- The new one, complete with decls and versions
237 Bool) -- True <=> there was an old Iface, and the new one
238 -- is identical, so no need to write it
240 mkIface hsc_env maybe_old_iface
241 (ModGuts{ mg_module = this_mod,
245 mg_rdr_env = rdr_env,
246 mg_fix_env = fix_env,
247 mg_deprecs = src_deprecs,
248 mg_hpc_info = hpc_info })
249 (ModDetails{ md_insts = insts,
250 md_fam_insts = fam_insts,
252 md_vect_info = vect_info,
254 md_exports = exports })
256 -- NB: notice that mkIface does not look at the bindings
257 -- only at the TypeEnv. The previous Tidy phase has
258 -- put exactly the info into the TypeEnv that we want
259 -- to expose in the interface
261 = do { eps <- hscEPS hsc_env
262 ; let { entities = typeEnvElts type_env ;
263 decls = [ tyThingToIfaceDecl entity
264 | entity <- entities,
265 let name = getName entity,
266 not (isImplicitTyThing entity),
267 -- No implicit Ids and class tycons in the interface file
268 not (isWiredInName name),
269 -- Nor wired-in things; the compiler knows about them anyhow
270 nameIsLocalOrFrom this_mod name ]
271 -- Sigh: see Note [Root-main Id] in TcRnDriver
273 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
274 ; deprecs = mkIfaceDeprec src_deprecs
275 ; iface_rules = map (coreRuleToIfaceRule this_mod) rules
276 ; iface_insts = map instanceToIfaceInst insts
277 ; iface_fam_insts = map famInstToIfaceFamInst fam_insts
278 ; iface_vect_info = flattenVectInfo vect_info
280 ; intermediate_iface = ModIface {
281 mi_module = this_mod,
285 mi_exports = mkIfaceExports exports,
287 -- Sort these lexicographically, so that
288 -- the result is stable across compilations
289 mi_insts = sortLe le_inst iface_insts,
290 mi_fam_insts= sortLe le_fam_inst iface_fam_insts,
291 mi_rules = sortLe le_rule iface_rules,
293 mi_vect_info = iface_vect_info,
295 mi_fixities = fixities,
296 mi_deprecs = deprecs,
297 mi_globals = Just rdr_env,
299 -- Left out deliberately: filled in by addVersionInfo
300 mi_mod_vers = initialVersion,
301 mi_exp_vers = initialVersion,
302 mi_rule_vers = initialVersion,
303 mi_orphan = False, -- Always set by addVersionInfo, but
304 -- it's a strict field, so we can't omit it.
305 mi_finsts = False, -- Ditto
306 mi_decls = deliberatelyOmitted "decls",
307 mi_ver_fn = deliberatelyOmitted "ver_fn",
308 mi_hpc = isHpcUsed hpc_info,
310 -- And build the cached values
311 mi_dep_fn = mkIfaceDepCache deprecs,
312 mi_fix_fn = mkIfaceFixCache fixities }
314 -- Add version information
315 ; ext_ver_fn = mkParentVerFun hsc_env eps
316 ; (new_iface, no_change_at_all, pp_diffs, pp_orphs)
317 = {-# SCC "versioninfo" #-}
318 addVersionInfo ext_ver_fn maybe_old_iface
319 intermediate_iface decls
323 ; when (isJust pp_orphs && dopt Opt_WarnOrphans dflags)
324 (printDump (expectJust "mkIface" pp_orphs))
325 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
326 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
327 (pprModIface new_iface)
329 ; return (new_iface, no_change_at_all) }
331 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
332 i1 `le_inst` i2 = ifDFun i1 `le_occ` ifDFun i2
333 i1 `le_fam_inst` i2 = ifFamInstTcName i1 `le_occ` ifFamInstTcName i2
335 le_occ :: Name -> Name -> Bool
336 -- Compare lexicographically by OccName, *not* by unique, because
337 -- the latter is not stable across compilations
338 le_occ n1 n2 = nameOccName n1 <= nameOccName n2
340 dflags = hsc_dflags hsc_env
341 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
342 ifFamInstTcName = ifaceTyConName . ifFamInstTyCon
344 flattenVectInfo (VectInfo { vectInfoVar = vVar
345 , vectInfoTyCon = vTyCon
348 ifaceVectInfoVar = [ Var.varName v
349 | (v, _) <- varEnvElts vVar],
350 ifaceVectInfoTyCon = [ tyConName t
351 | (t, t_v) <- nameEnvElts vTyCon
353 ifaceVectInfoTyConReuse = [ tyConName t
354 | (t, t_v) <- nameEnvElts vTyCon
358 -----------------------------
359 writeIfaceFile :: DynFlags -> ModLocation -> ModIface -> IO ()
360 writeIfaceFile dflags location new_iface
361 = do createDirectoryHierarchy (directoryOf hi_file_path)
362 writeBinIface dflags hi_file_path new_iface
363 where hi_file_path = ml_hi_file location
366 -- -----------------------------------------------------------------------------
367 -- Look up parents and versions of Names
369 -- This is like a global version of the mi_ver_fn field in each ModIface.
370 -- Given a Name, it finds the ModIface, and then uses mi_ver_fn to get
371 -- the parent and version info.
374 :: HscEnv -- needed to look up versions
375 -> ExternalPackageState -- ditto
376 -> (Name -> (OccName,Version))
377 mkParentVerFun hsc_env eps
380 mod = nameModule name
381 occ = nameOccName name
382 iface = lookupIfaceByModule (hsc_dflags hsc_env) hpt pit mod `orElse`
383 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
385 mi_ver_fn iface occ `orElse`
386 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
388 hpt = hsc_HPT hsc_env
391 -----------------------------------------------------------------------------
392 -- Compute version numbers for local decls
395 :: (Name -> (OccName,Version)) -- lookup parents and versions of names
396 -> Maybe ModIface -- The old interface, read from M.hi
397 -> ModIface -- The new interface (lacking decls)
398 -> [IfaceDecl] -- The new decls
399 -> (ModIface, -- Updated interface
400 Bool, -- True <=> no changes at all; no need to write Iface
402 Maybe SDoc) -- Warnings about orphans
404 addVersionInfo ver_fn Nothing new_iface new_decls
405 -- No old interface, so definitely write a new one!
406 = (new_iface { mi_orphan = not (null orph_insts && null orph_rules)
407 , mi_finsts = not . null $ mi_fam_insts new_iface
408 , mi_decls = [(initialVersion, decl) | decl <- new_decls]
409 , mi_ver_fn = mkIfaceVerCache (zip (repeat initialVersion)
413 ptext SLIT("No old interface file"),
414 pprOrphans orph_insts orph_rules)
416 orph_insts = filter (isNothing . ifInstOrph) (mi_insts new_iface)
417 orph_rules = filter (isNothing . ifRuleOrph) (mi_rules new_iface)
419 addVersionInfo ver_fn (Just old_iface@(ModIface {
420 mi_mod_vers = old_mod_vers,
421 mi_exp_vers = old_exp_vers,
422 mi_rule_vers = old_rule_vers,
423 mi_decls = old_decls,
424 mi_ver_fn = old_decl_vers,
425 mi_fix_fn = old_fixities }))
426 new_iface@(ModIface { mi_fix_fn = new_fixities })
429 = (old_iface, True, ptext SLIT("Interface file unchanged"), pp_orphs)
431 = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
432 nest 2 pp_diffs], pp_orphs)
434 final_iface = new_iface {
435 mi_mod_vers = bump_unless no_output_change old_mod_vers,
436 mi_exp_vers = bump_unless no_export_change old_exp_vers,
437 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
438 mi_orphan = not (null new_orph_rules && null new_orph_insts),
439 mi_finsts = not . null $ mi_fam_insts new_iface,
440 mi_decls = decls_w_vers,
441 mi_ver_fn = mkIfaceVerCache decls_w_vers }
443 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
446 (old_non_orph_insts, old_orph_insts) =
447 mkOrphMap ifInstOrph (mi_insts old_iface)
448 (new_non_orph_insts, new_orph_insts) =
449 mkOrphMap ifInstOrph (mi_insts new_iface)
450 old_fam_insts = mi_fam_insts old_iface
451 new_fam_insts = mi_fam_insts new_iface
452 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
453 (lookupOccEnv old_non_orph_insts occ)
454 (lookupOccEnv new_non_orph_insts occ)
456 (old_non_orph_rules, old_orph_rules) =
457 mkOrphMap ifRuleOrph (mi_rules old_iface)
458 (new_non_orph_rules, new_orph_rules) =
459 mkOrphMap ifRuleOrph (mi_rules new_iface)
460 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
461 (lookupOccEnv old_non_orph_rules occ)
462 (lookupOccEnv new_non_orph_rules occ)
464 -- Computing what changed
465 no_output_change = no_decl_change && no_rule_change &&
466 no_export_change && no_deprec_change
467 no_export_change = mi_exports new_iface == mi_exports old_iface
469 no_decl_change = isEmptyOccSet changed_occs
470 no_rule_change = not (changedWrtNames changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
471 || changedWrtNames changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts)
472 || changedWrtNames changed_occs (eqListBy eqIfFamInst old_fam_insts new_fam_insts))
473 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
475 -- If the usages havn't changed either, we don't need to write the interface file
476 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
477 mi_deps new_iface == mi_deps old_iface &&
478 mi_hpc new_iface == mi_hpc old_iface
479 no_change_at_all = no_output_change && no_other_changes
481 pp_diffs = vcat [pp_change no_export_change "Export list"
482 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
483 pp_change no_rule_change "Rules"
484 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
485 pp_change no_deprec_change "Deprecations" empty,
486 pp_change no_other_changes "Usages" empty,
488 pp_change True what info = empty
489 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
492 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
493 same_fixity n = bool (old_fixities n == new_fixities n)
496 -- Adding version info
497 new_version = bumpVersion old_mod_vers
498 -- Start from the old module version, not from
499 -- zero so that if you remove f, and then add
500 -- it again, you don't thereby reduce f's
503 add_vers decl | occ `elemOccSet` changed_occs = new_version
504 | otherwise = snd (expectJust "add_vers" (old_decl_vers occ))
505 -- If it's unchanged, there jolly well
506 where -- should be an old version number
510 -- Deciding which declarations have changed
512 -- For each local decl, the IfaceEq gives the list of things that
513 -- must be unchanged for the declaration as a whole to be unchanged.
514 eq_info :: [(OccName, IfaceEq)]
515 eq_info = map check_eq new_decls
517 | Just old_decl <- lookupOccEnv old_decl_env occ
518 = (occ, new_decl `eqIfDecl` old_decl &&& eq_indirects new_decl)
519 | otherwise {- No corresponding old decl -}
522 occ = ifName new_decl
524 eq_indirects :: IfaceDecl -> IfaceEq
525 -- When seeing if two decls are the same, remember to
526 -- check whether any relevant fixity or rules have changed
527 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
528 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
529 = same_insts cls_occ &&&
530 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
531 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
532 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
533 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
534 eq_indirects other = Equal -- Synonyms and foreign declarations
536 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
537 eq_ind_occ occ = same_fixity occ &&& same_rules occ
538 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
540 -- The Occs of declarations that changed.
541 changed_occs :: OccSet
542 changed_occs = computeChangedOccs ver_fn (mi_module new_iface)
543 (mi_usages old_iface) eq_info
547 pp_decl_diffs :: SDoc -- Nothing => no changes
549 | isEmptyOccSet changed_occs = empty
551 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
552 ptext SLIT("Version change for these decls:"),
553 nest 2 (vcat (map show_change new_decls))]
555 eq_env = mkOccEnv eq_info
557 | not (occ `elemOccSet` changed_occs) = empty
559 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
562 occ = ifName new_decl
563 why = case lookupOccEnv eq_env occ of
564 Just (EqBut names) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:") <> ppr names,
565 nest 2 (braces (fsep (map ppr (occSetElts
566 (occs `intersectOccSet` changed_occs)))))]
567 where occs = mkOccSet (map nameOccName (nameSetToList names))
569 | Just old_decl <- lookupOccEnv old_decl_env occ
570 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
571 ptext SLIT("New:") <+> ppr new_decl]
573 -> ppr occ <+> ptext SLIT("only in new interface")
574 other -> pprPanic "MkIface.show_change" (ppr occ)
576 pp_orphs = pprOrphans new_orph_insts new_orph_rules
579 pprOrphans insts rules
580 | null insts && null rules = Nothing
583 if null insts then empty else
584 hang (ptext SLIT("Warning: orphan instances:"))
585 2 (vcat (map ppr insts)),
586 if null rules then empty else
587 hang (ptext SLIT("Warning: orphan rules:"))
588 2 (vcat (map ppr rules))
592 :: (Name -> (OccName,Version)) -- get parents and versions
593 -> Module -- This module
594 -> [Usage] -- Usages from old iface
595 -> [(OccName, IfaceEq)] -- decl names, equality conditions
596 -> OccSet -- set of things that have changed
597 computeChangedOccs ver_fn this_module old_usages eq_info
598 = foldl add_changes emptyOccSet (stronglyConnComp edges)
601 -- return True if an external name has changed
602 name_changed :: Name -> Bool
604 | Just ents <- lookupUFM usg_modmap (moduleName mod)
605 = case lookupUFM ents parent_occ of
606 Nothing -> pprPanic "computeChangedOccs" (ppr nm)
607 Just v -> v < new_version
608 | otherwise = False -- must be in another package
611 (parent_occ, new_version) = ver_fn nm
613 -- Turn the usages from the old ModIface into a mapping
614 usg_modmap = listToUFM [ (usg_mod usg, listToUFM (usg_entities usg))
615 | usg <- old_usages ]
617 get_local_eq_info :: GenIfaceEq NameSet -> GenIfaceEq OccSet
618 get_local_eq_info Equal = Equal
619 get_local_eq_info NotEqual = NotEqual
620 get_local_eq_info (EqBut ns) = foldNameSet f Equal ns
621 where f name eq | nameModule name == this_module =
622 EqBut (unitOccSet (nameOccName name)) `and_occifeq` eq
623 | name_changed name = NotEqual
626 local_eq_infos = mapSnd get_local_eq_info eq_info
628 edges :: [((OccName, OccIfaceEq), Unique, [Unique])]
629 edges = [ (node, getUnique occ, map getUnique occs)
630 | node@(occ, iface_eq) <- local_eq_infos
631 , let occs = case iface_eq of
632 EqBut occ_set -> occSetElts occ_set
635 -- Changes in declarations
636 add_changes :: OccSet -> SCC (OccName, OccIfaceEq) -> OccSet
637 add_changes so_far (AcyclicSCC (occ, iface_eq))
638 | changedWrt so_far iface_eq -- This one has changed
639 = extendOccSet so_far occ
640 add_changes so_far (CyclicSCC pairs)
641 | changedWrt so_far (foldr1 and_occifeq iface_eqs)
642 -- One of this group has changed
643 = extendOccSetList so_far occs
644 where (occs, iface_eqs) = unzip pairs
645 add_changes so_far other = so_far
647 type OccIfaceEq = GenIfaceEq OccSet
649 changedWrt :: OccSet -> OccIfaceEq -> Bool
650 changedWrt so_far Equal = False
651 changedWrt so_far NotEqual = True
652 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
654 changedWrtNames :: OccSet -> IfaceEq -> Bool
655 changedWrtNames so_far Equal = False
656 changedWrtNames so_far NotEqual = True
657 changedWrtNames so_far (EqBut kids) =
658 so_far `intersectsOccSet` mkOccSet (map nameOccName (nameSetToList kids))
660 and_occifeq :: OccIfaceEq -> OccIfaceEq -> OccIfaceEq
661 Equal `and_occifeq` x = x
662 NotEqual `and_occifeq` x = NotEqual
663 EqBut nms `and_occifeq` Equal = EqBut nms
664 EqBut nms `and_occifeq` NotEqual = NotEqual
665 EqBut nms1 `and_occifeq` EqBut nms2 = EqBut (nms1 `unionOccSets` nms2)
667 ----------------------
668 -- mkOrphMap partitions instance decls or rules into
669 -- (a) an OccEnv for ones that are not orphans,
670 -- mapping the local OccName to a list of its decls
671 -- (b) a list of orphan decls
672 mkOrphMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
673 -- Nothing for an orphan decl
674 -> [decl] -- Sorted into canonical order
675 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
676 -- each sublist in canonical order
677 [decl]) -- Orphan decls; in canonical order
678 mkOrphMap get_key decls
679 = foldl go (emptyOccEnv, []) decls
681 go (non_orphs, orphs) d
682 | Just occ <- get_key d
683 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
684 | otherwise = (non_orphs, d:orphs)
686 ----------------------
687 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
688 mkIfaceDeprec NoDeprecs = NoDeprecs
689 mkIfaceDeprec (DeprecAll t) = DeprecAll t
690 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
692 ----------------------
693 bump_unless :: Bool -> Version -> Version
694 bump_unless True v = v -- True <=> no change
695 bump_unless False v = bumpVersion v
699 %*********************************************************
701 \subsection{Keeping track of what we've slurped, and version numbers}
703 %*********************************************************
707 mkUsageInfo :: HscEnv
708 -> ModuleEnv (Module, Bool, SrcSpan)
709 -> [(ModuleName, IsBootInterface)]
710 -> NameSet -> IO [Usage]
711 mkUsageInfo hsc_env dir_imp_mods dep_mods used_names
712 = do { eps <- hscEPS hsc_env
713 ; let usages = mk_usage_info (eps_PIT eps) hsc_env
714 dir_imp_mods dep_mods used_names
715 ; usages `seqList` return usages }
716 -- seq the list of Usages returned: occasionally these
717 -- don't get evaluated for a while and we can end up hanging on to
718 -- the entire collection of Ifaces.
720 mk_usage_info pit hsc_env dir_imp_mods dep_mods used_names
721 = mapCatMaybes mkUsage dep_mods
722 -- ToDo: do we need to sort into canonical order?
724 hpt = hsc_HPT hsc_env
725 dflags = hsc_dflags hsc_env
727 -- ent_map groups together all the things imported and used
728 -- from a particular module in this package
729 ent_map :: ModuleEnv [OccName]
730 ent_map = foldNameSet add_mv emptyModuleEnv used_names
732 | isWiredInName name = mv_map -- ignore wired-in names
734 = case nameModule_maybe name of
735 Nothing -> mv_map -- ignore internal names
736 Just mod -> extendModuleEnv_C add_item mv_map mod [occ]
738 occ = nameOccName name
739 add_item occs _ = occ:occs
741 depend_on_exports mod = case lookupModuleEnv dir_imp_mods mod of
742 Just (_,no_imp,_) -> not no_imp
745 -- We want to create a Usage for a home module if
746 -- a) we used something from; has something in used_names
747 -- b) we imported all of it, even if we used nothing from it
748 -- (need to recompile if its export list changes: export_vers)
749 -- c) is a home-package orphan or family-instance module (need to
750 -- recompile if its instance decls change: rules_vers)
751 mkUsage :: (ModuleName, IsBootInterface) -> Maybe Usage
752 mkUsage (mod_name, _)
753 | isNothing maybe_iface -- We can't depend on it if we didn't
754 || (null used_occs -- load its interface.
755 && isNothing export_vers
758 = Nothing -- Record no usage info
761 = Just (Usage { usg_name = mod_name,
763 usg_exports = export_vers,
764 usg_entities = fmToList ent_vers,
765 usg_rules = rules_vers })
767 maybe_iface = lookupIfaceByModule dflags hpt pit mod
768 -- In one-shot mode, the interfaces for home-package
769 -- modules accumulate in the PIT not HPT. Sigh.
771 mod = mkModule (thisPackage dflags) mod_name
773 Just iface = maybe_iface
774 orphan_mod = mi_orphan iface
775 finsts_mod = mi_finsts iface
776 version_env = mi_ver_fn iface
777 mod_vers = mi_mod_vers iface
778 rules_vers = mi_rule_vers iface
779 export_vers | depend_on_exports mod = Just (mi_exp_vers iface)
780 | otherwise = Nothing
782 used_occs = lookupModuleEnv ent_map mod `orElse` []
784 -- Making a FiniteMap here ensures that (a) we remove duplicates
785 -- when we have usages on several subordinates of a single parent,
786 -- and (b) that the usages emerge in a canonical order, which
787 -- is why we use FiniteMap rather than OccEnv: FiniteMap works
788 -- using Ord on the OccNames, which is a lexicographic ordering.
789 ent_vers :: FiniteMap OccName Version
790 ent_vers = listToFM (map lookup_occ used_occs)
793 case version_env occ of
794 Nothing -> pprTrace "hmm, strange" (ppr mod <+> ppr occ) $
795 (occ, initialVersion) -- does this ever happen?
796 Just (parent, version) -> (parent, version)
800 mkIfaceExports :: [AvailInfo]
801 -> [(Module, [GenAvailInfo OccName])]
802 -- Group by module and sort by occurrence
803 -- This keeps the list in canonical order
804 mkIfaceExports exports
805 = [ (mod, eltsFM avails)
806 | (mod, avails) <- fmToList groupFM
809 -- Group by the module where the exported entities are defined
810 -- (which may not be the same for all Names in an Avail)
811 -- Deliberately use FiniteMap rather than UniqFM so we
812 -- get a canonical ordering
813 groupFM :: ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
814 groupFM = foldl add emptyModuleEnv exports
816 add_one :: ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
817 -> Module -> GenAvailInfo OccName
818 -> ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
819 add_one env mod avail
820 = extendModuleEnv_C plusFM env mod
821 (unitFM (occNameFS (availName avail)) avail)
823 -- NB: we should not get T(X) and T(Y) in the export list
824 -- else the plusFM will simply discard one! They
825 -- should have been combined by now.
827 = add_one env (nameModule n) (Avail (nameOccName n))
829 add env (AvailTC tc ns)
830 = foldl add_for_mod env mods
832 tc_occ = nameOccName tc
833 mods = nub (map nameModule ns)
834 -- Usually just one, but see Note [Original module]
837 = add_one env mod (AvailTC tc_occ names_from_mod)
839 names_from_mod = [nameOccName n | n <- ns, nameModule n == mod]
842 Note [Orignal module]
843 ~~~~~~~~~~~~~~~~~~~~~
845 module X where { data family T }
846 module Y( T(..) ) where { import X; data instance T Int = MkT Int }
847 The exported Avail from Y will look like
850 - only MkT is brought into scope by the data instance;
851 - but the parent (used for grouping and naming in T(..) exports) is X.T
852 - and in this case we export X.T too
854 In the result of MkIfaceExports, the names are grouped by defining module,
855 so we may need to split up a single Avail into multiple ones.
858 %************************************************************************
860 Load the old interface file for this module (unless
861 we have it aleady), and check whether it is up to date
864 %************************************************************************
867 checkOldIface :: HscEnv
869 -> Bool -- Source unchanged
870 -> Maybe ModIface -- Old interface from compilation manager, if any
871 -> IO (RecompileRequired, Maybe ModIface)
873 checkOldIface hsc_env mod_summary source_unchanged maybe_iface
874 = do { showPass (hsc_dflags hsc_env)
875 ("Checking old interface for " ++
876 showSDoc (ppr (ms_mod mod_summary))) ;
878 ; initIfaceCheck hsc_env $
879 check_old_iface hsc_env mod_summary source_unchanged maybe_iface
882 check_old_iface hsc_env mod_summary source_unchanged maybe_iface
883 = do -- CHECK WHETHER THE SOURCE HAS CHANGED
884 { ifM (not source_unchanged)
885 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
887 -- If the source has changed and we're in interactive mode, avoid reading
888 -- an interface; just return the one we might have been supplied with.
889 ; let dflags = hsc_dflags hsc_env
890 ; if not (isObjectTarget (hscTarget dflags)) && not source_unchanged then
891 return (outOfDate, maybe_iface)
893 case maybe_iface of {
894 Just old_iface -> do -- Use the one we already have
895 { traceIf (text "We already have the old interface for" <+> ppr (ms_mod mod_summary))
896 ; recomp <- checkVersions hsc_env source_unchanged mod_summary old_iface
897 ; return (recomp, Just old_iface) }
901 -- Try and read the old interface for the current module
902 -- from the .hi file left from the last time we compiled it
903 { let iface_path = msHiFilePath mod_summary
904 ; read_result <- readIface (ms_mod mod_summary) iface_path False
905 ; case read_result of {
906 Failed err -> do -- Old interface file not found, or garbled; give up
907 { traceIf (text "FYI: cannot read old interface file:"
909 ; return (outOfDate, Nothing) }
911 ; Succeeded iface -> do
913 -- We have got the old iface; check its versions
914 { traceIf (text "Read the interface file" <+> text iface_path)
915 ; recomp <- checkVersions hsc_env source_unchanged mod_summary iface
916 ; returnM (recomp, Just iface)
921 @recompileRequired@ is called from the HscMain. It checks whether
922 a recompilation is required. It needs access to the persistent state,
923 finder, etc, because it may have to load lots of interface files to
924 check their versions.
927 type RecompileRequired = Bool
928 upToDate = False -- Recompile not required
929 outOfDate = True -- Recompile required
931 checkVersions :: HscEnv
932 -> Bool -- True <=> source unchanged
934 -> ModIface -- Old interface
935 -> IfG RecompileRequired
936 checkVersions hsc_env source_unchanged mod_summary iface
937 | not source_unchanged
940 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
941 ppr (mi_module iface) <> colon)
943 ; recomp <- checkDependencies hsc_env mod_summary iface
944 ; if recomp then return outOfDate else do {
946 -- Source code unchanged and no errors yet... carry on
948 -- First put the dependent-module info, read from the old interface, into the envt,
949 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
951 -- It's just temporary because either the usage check will succeed
952 -- (in which case we are done with this module) or it'll fail (in which
953 -- case we'll compile the module from scratch anyhow).
955 -- We do this regardless of compilation mode, although in --make mode
956 -- all the dependent modules should be in the HPT already, so it's
958 updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
960 ; let this_pkg = thisPackage (hsc_dflags hsc_env)
961 ; checkList [checkModUsage this_pkg u | u <- mi_usages iface]
964 -- This is a bit of a hack really
965 mod_deps :: ModuleNameEnv (ModuleName, IsBootInterface)
966 mod_deps = mkModDeps (dep_mods (mi_deps iface))
969 -- If the direct imports of this module are resolved to targets that
970 -- are not among the dependencies of the previous interface file,
971 -- then we definitely need to recompile. This catches cases like
972 -- - an exposed package has been upgraded
973 -- - we are compiling with different package flags
974 -- - a home module that was shadowing a package module has been removed
975 -- - a new home module has been added that shadows a package module
978 -- Returns True if recompilation is required.
979 checkDependencies :: HscEnv -> ModSummary -> ModIface -> IfG RecompileRequired
980 checkDependencies hsc_env summary iface
981 = orM (map dep_missing (ms_imps summary ++ ms_srcimps summary))
983 prev_dep_mods = dep_mods (mi_deps iface)
984 prev_dep_pkgs = dep_pkgs (mi_deps iface)
986 this_pkg = thisPackage (hsc_dflags hsc_env)
988 orM = foldr f (return False)
989 where f m rest = do b <- m; if b then return True else rest
991 dep_missing (L _ mod) = do
992 find_res <- ioToIOEnv $ findImportedModule hsc_env mod Nothing
996 -> if moduleName mod `notElem` map fst prev_dep_mods
997 then do traceHiDiffs $
998 text "imported module " <> quotes (ppr mod) <>
999 text " not among previous dependencies"
1004 -> if pkg `notElem` prev_dep_pkgs
1005 then do traceHiDiffs $
1006 text "imported module " <> quotes (ppr mod) <>
1007 text " is from package " <> quotes (ppr pkg) <>
1008 text ", which is not among previous dependencies"
1012 where pkg = modulePackageId mod
1013 _otherwise -> return outOfDate
1015 checkModUsage :: PackageId ->Usage -> IfG RecompileRequired
1016 -- Given the usage information extracted from the old
1017 -- M.hi file for the module being compiled, figure out
1018 -- whether M needs to be recompiled.
1020 checkModUsage this_pkg (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
1021 usg_rules = old_rule_vers,
1022 usg_exports = maybe_old_export_vers,
1023 usg_entities = old_decl_vers })
1024 = -- Load the imported interface is possible
1026 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
1028 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
1031 mod = mkModule this_pkg mod_name
1033 loadInterface doc_str mod ImportBySystem `thenM` \ mb_iface ->
1034 -- Load the interface, but don't complain on failure;
1035 -- Instead, get an Either back which we can test
1038 Failed exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
1040 -- Couldn't find or parse a module mentioned in the
1041 -- old interface file. Don't complain -- it might just be that
1042 -- the current module doesn't need that import and it's been deleted
1046 new_mod_vers = mi_mod_vers iface
1047 new_decl_vers = mi_ver_fn iface
1048 new_export_vers = mi_exp_vers iface
1049 new_rule_vers = mi_rule_vers iface
1052 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
1053 if not recompile then
1057 -- CHECK EXPORT LIST
1058 if checkExportList maybe_old_export_vers new_export_vers then
1059 out_of_date_vers (ptext SLIT(" Export list changed"))
1060 (expectJust "checkModUsage" maybe_old_export_vers)
1065 if old_rule_vers /= new_rule_vers then
1066 out_of_date_vers (ptext SLIT(" Rules changed"))
1067 old_rule_vers new_rule_vers
1070 -- CHECK ITEMS ONE BY ONE
1071 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
1073 returnM outOfDate -- This one failed, so just bail out now
1075 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
1078 ------------------------
1079 checkModuleVersion old_mod_vers new_mod_vers
1080 | new_mod_vers == old_mod_vers
1081 = up_to_date (ptext SLIT("Module version unchanged"))
1084 = out_of_date_vers (ptext SLIT(" Module version has changed"))
1085 old_mod_vers new_mod_vers
1087 ------------------------
1088 checkExportList Nothing new_vers = upToDate
1089 checkExportList (Just v) new_vers = v /= new_vers
1091 ------------------------
1092 checkEntityUsage new_vers (name,old_vers)
1093 = case new_vers name of
1095 Nothing -> -- We used it before, but it ain't there now
1096 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
1098 Just (_, new_vers) -- It's there, but is it up to date?
1099 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
1101 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
1104 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
1105 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
1106 out_of_date_vers msg old_vers new_vers
1107 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
1109 ----------------------
1110 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
1111 -- This helper is used in two places
1112 checkList [] = returnM upToDate
1113 checkList (check:checks) = check `thenM` \ recompile ->
1120 %************************************************************************
1122 Converting things to their Iface equivalents
1124 %************************************************************************
1127 tyThingToIfaceDecl :: TyThing -> IfaceDecl
1128 -- Assumption: the thing is already tidied, so that locally-bound names
1129 -- (lambdas, for-alls) already have non-clashing OccNames
1130 -- Reason: Iface stuff uses OccNames, and the conversion here does
1131 -- not do tidying on the way
1132 tyThingToIfaceDecl (AnId id)
1133 = IfaceId { ifName = getOccName id,
1134 ifType = toIfaceType (idType id),
1137 info = case toIfaceIdInfo (idInfo id) of
1139 items -> HasInfo items
1141 tyThingToIfaceDecl (AClass clas)
1142 = IfaceClass { ifCtxt = toIfaceContext sc_theta,
1143 ifName = getOccName clas,
1144 ifTyVars = toIfaceTvBndrs clas_tyvars,
1145 ifFDs = map toIfaceFD clas_fds,
1146 ifATs = map (tyThingToIfaceDecl . ATyCon) clas_ats,
1147 ifSigs = map toIfaceClassOp op_stuff,
1148 ifRec = boolToRecFlag (isRecursiveTyCon tycon) }
1150 (clas_tyvars, clas_fds, sc_theta, _, clas_ats, op_stuff)
1151 = classExtraBigSig clas
1152 tycon = classTyCon clas
1154 toIfaceClassOp (sel_id, def_meth)
1155 = ASSERT(sel_tyvars == clas_tyvars)
1156 IfaceClassOp (getOccName sel_id) def_meth (toIfaceType op_ty)
1158 -- Be careful when splitting the type, because of things
1159 -- like class Foo a where
1160 -- op :: (?x :: String) => a -> a
1161 -- and class Baz a where
1162 -- op :: (Ord a) => a -> a
1163 (sel_tyvars, rho_ty) = splitForAllTys (idType sel_id)
1164 op_ty = funResultTy rho_ty
1166 toIfaceFD (tvs1, tvs2) = (map getFS tvs1, map getFS tvs2)
1168 tyThingToIfaceDecl (ATyCon tycon)
1170 = IfaceSyn { ifName = getOccName tycon,
1171 ifTyVars = toIfaceTvBndrs tyvars,
1172 ifOpenSyn = syn_isOpen,
1173 ifSynRhs = toIfaceType syn_tyki,
1174 ifFamInst = famInstToIface (tyConFamInst_maybe tycon)
1178 = IfaceData { ifName = getOccName tycon,
1179 ifTyVars = toIfaceTvBndrs tyvars,
1180 ifCtxt = toIfaceContext (tyConStupidTheta tycon),
1181 ifCons = ifaceConDecls (algTyConRhs tycon),
1182 ifRec = boolToRecFlag (isRecursiveTyCon tycon),
1183 ifGadtSyntax = isGadtSyntaxTyCon tycon,
1184 ifGeneric = tyConHasGenerics tycon,
1185 ifFamInst = famInstToIface (tyConFamInst_maybe tycon)}
1187 | isForeignTyCon tycon
1188 = IfaceForeign { ifName = getOccName tycon,
1189 ifExtName = tyConExtName tycon }
1191 | otherwise = pprPanic "toIfaceDecl" (ppr tycon)
1193 tyvars = tyConTyVars tycon
1194 (syn_isOpen, syn_tyki) = case synTyConRhs tycon of
1195 OpenSynTyCon ki _ -> (True , ki)
1196 SynonymTyCon ty -> (False, ty)
1198 ifaceConDecls (NewTyCon { data_con = con }) =
1199 IfNewTyCon (ifaceConDecl con)
1200 ifaceConDecls (DataTyCon { data_cons = cons }) =
1201 IfDataTyCon (map ifaceConDecl cons)
1202 ifaceConDecls OpenTyCon {} = IfOpenDataTyCon
1203 ifaceConDecls AbstractTyCon = IfAbstractTyCon
1204 -- The last case happens when a TyCon has been trimmed during tidying
1205 -- Furthermore, tyThingToIfaceDecl is also used
1206 -- in TcRnDriver for GHCi, when browsing a module, in which case the
1207 -- AbstractTyCon case is perfectly sensible.
1209 ifaceConDecl data_con
1210 = IfCon { ifConOcc = getOccName (dataConName data_con),
1211 ifConInfix = dataConIsInfix data_con,
1212 ifConUnivTvs = toIfaceTvBndrs (dataConUnivTyVars data_con),
1213 ifConExTvs = toIfaceTvBndrs (dataConExTyVars data_con),
1214 ifConEqSpec = to_eq_spec (dataConEqSpec data_con),
1215 ifConCtxt = toIfaceContext (dataConTheta data_con),
1216 ifConArgTys = map toIfaceType (dataConOrigArgTys data_con),
1217 ifConFields = map getOccName
1218 (dataConFieldLabels data_con),
1219 ifConStricts = dataConStrictMarks data_con }
1221 to_eq_spec spec = [(getOccName tv, toIfaceType ty) | (tv,ty) <- spec]
1223 famInstToIface Nothing = Nothing
1224 famInstToIface (Just (famTyCon, instTys)) =
1225 Just (toIfaceTyCon famTyCon, map toIfaceType instTys)
1227 tyThingToIfaceDecl (ADataCon dc)
1228 = pprPanic "toIfaceDecl" (ppr dc) -- Should be trimmed out earlier
1231 getFS x = occNameFS (getOccName x)
1233 --------------------------
1234 instanceToIfaceInst :: Instance -> IfaceInst
1235 instanceToIfaceInst ispec@(Instance { is_dfun = dfun_id, is_flag = oflag,
1236 is_cls = cls_name, is_tcs = mb_tcs })
1237 = ASSERT( cls_name == className cls )
1238 IfaceInst { ifDFun = dfun_name,
1240 ifInstCls = cls_name,
1241 ifInstTys = map do_rough mb_tcs,
1244 do_rough Nothing = Nothing
1245 do_rough (Just n) = Just (toIfaceTyCon_name n)
1247 dfun_name = idName dfun_id
1248 mod = nameModule dfun_name
1249 is_local name = nameIsLocalOrFrom mod name
1251 -- Compute orphanhood. See Note [Orphans] in IfaceSyn
1252 (_, _, cls, tys) = tcSplitDFunTy (idType dfun_id)
1253 -- Slightly awkward: we need the Class to get the fundeps
1254 (tvs, fds) = classTvsFds cls
1255 arg_names = [filterNameSet is_local (tyClsNamesOfType ty) | ty <- tys]
1256 orph | is_local cls_name = Just (nameOccName cls_name)
1257 | all isJust mb_ns = head mb_ns
1258 | otherwise = Nothing
1260 mb_ns :: [Maybe OccName] -- One for each fundep; a locally-defined name
1261 -- that is not in the "determined" arguments
1262 mb_ns | null fds = [choose_one arg_names]
1263 | otherwise = map do_one fds
1264 do_one (ltvs,rtvs) = choose_one [ns | (tv,ns) <- tvs `zip` arg_names
1265 , not (tv `elem` rtvs)]
1267 choose_one :: [NameSet] -> Maybe OccName
1268 choose_one nss = case nameSetToList (unionManyNameSets nss) of
1270 (n:ns) -> Just (nameOccName n)
1272 --------------------------
1273 famInstToIfaceFamInst :: FamInst -> IfaceFamInst
1274 famInstToIfaceFamInst fi@(FamInst { fi_tycon = tycon,
1275 fi_fam = fam, fi_tcs = mb_tcs })
1276 = IfaceFamInst { ifFamInstTyCon = toIfaceTyCon tycon
1277 , ifFamInstFam = fam
1278 , ifFamInstTys = map do_rough mb_tcs }
1280 do_rough Nothing = Nothing
1281 do_rough (Just n) = Just (toIfaceTyCon_name n)
1283 --------------------------
1284 toIfaceLetBndr id = IfLetBndr (occNameFS (getOccName id))
1285 (toIfaceType (idType id))
1288 -- Stripped-down version of tcIfaceIdInfo
1289 -- Change this if you want to export more IdInfo for
1290 -- non-top-level Ids. Don't forget to change
1291 -- CoreTidy.tidyLetBndr too!
1293 -- See Note [IdInfo on nested let-bindings] in IfaceSyn
1295 inline_prag = inlinePragInfo id_info
1296 prag_info | isAlwaysActive inline_prag = NoInfo
1297 | otherwise = HasInfo [HsInline inline_prag]
1299 --------------------------
1300 toIfaceIdInfo :: IdInfo -> [IfaceInfoItem]
1301 toIfaceIdInfo id_info
1302 = catMaybes [arity_hsinfo, caf_hsinfo, strict_hsinfo,
1303 inline_hsinfo, wrkr_hsinfo, unfold_hsinfo]
1305 ------------ Arity --------------
1306 arity_info = arityInfo id_info
1307 arity_hsinfo | arity_info == 0 = Nothing
1308 | otherwise = Just (HsArity arity_info)
1310 ------------ Caf Info --------------
1311 caf_info = cafInfo id_info
1312 caf_hsinfo = case caf_info of
1313 NoCafRefs -> Just HsNoCafRefs
1316 ------------ Strictness --------------
1317 -- No point in explicitly exporting TopSig
1318 strict_hsinfo = case newStrictnessInfo id_info of
1319 Just sig | not (isTopSig sig) -> Just (HsStrictness sig)
1322 ------------ Worker --------------
1323 work_info = workerInfo id_info
1324 has_worker = case work_info of { HasWorker _ _ -> True; other -> False }
1325 wrkr_hsinfo = case work_info of
1326 HasWorker work_id wrap_arity ->
1327 Just (HsWorker ((idName work_id)) wrap_arity)
1330 ------------ Unfolding --------------
1331 -- The unfolding is redundant if there is a worker
1332 unfold_info = unfoldingInfo id_info
1333 rhs = unfoldingTemplate unfold_info
1334 no_unfolding = neverUnfold unfold_info
1335 -- The CoreTidy phase retains unfolding info iff
1336 -- we want to expose the unfolding, taking into account
1337 -- unconditional NOINLINE, etc. See TidyPgm.addExternal
1338 unfold_hsinfo | no_unfolding = Nothing
1339 | has_worker = Nothing -- Unfolding is implicit
1340 | otherwise = Just (HsUnfold (toIfaceExpr rhs))
1342 ------------ Inline prag --------------
1343 inline_prag = inlinePragInfo id_info
1344 inline_hsinfo | isAlwaysActive inline_prag = Nothing
1345 | no_unfolding && not has_worker = Nothing
1346 -- If the iface file give no unfolding info, we
1347 -- don't need to say when inlining is OK!
1348 | otherwise = Just (HsInline inline_prag)
1350 --------------------------
1351 coreRuleToIfaceRule :: Module -> CoreRule -> IfaceRule
1352 coreRuleToIfaceRule mod (BuiltinRule { ru_fn = fn})
1353 = pprTrace "toHsRule: builtin" (ppr fn) $
1356 coreRuleToIfaceRule mod (Rule { ru_name = name, ru_fn = fn,
1357 ru_act = act, ru_bndrs = bndrs,
1358 ru_args = args, ru_rhs = rhs })
1359 = IfaceRule { ifRuleName = name, ifActivation = act,
1360 ifRuleBndrs = map toIfaceBndr bndrs,
1362 ifRuleArgs = map do_arg args,
1363 ifRuleRhs = toIfaceExpr rhs,
1366 -- For type args we must remove synonyms from the outermost
1367 -- level. Reason: so that when we read it back in we'll
1368 -- construct the same ru_rough field as we have right now;
1370 do_arg (Type ty) = IfaceType (toIfaceType (deNoteType ty))
1371 do_arg arg = toIfaceExpr arg
1373 -- Compute orphanhood. See Note [Orphans] in IfaceSyn
1374 -- A rule is an orphan only if none of the variables
1375 -- mentioned on its left-hand side are locally defined
1376 lhs_names = fn : nameSetToList (exprsFreeNames args)
1377 -- No need to delete bndrs, because
1378 -- exprsFreeNames finds only External names
1380 orph = case filter (nameIsLocalOrFrom mod) lhs_names of
1381 (n:ns) -> Just (nameOccName n)
1384 bogusIfaceRule :: Name -> IfaceRule
1385 bogusIfaceRule id_name
1386 = IfaceRule { ifRuleName = FSLIT("bogus"), ifActivation = NeverActive,
1387 ifRuleBndrs = [], ifRuleHead = id_name, ifRuleArgs = [],
1388 ifRuleRhs = IfaceExt id_name, ifRuleOrph = Nothing }
1390 ---------------------
1391 toIfaceExpr :: CoreExpr -> IfaceExpr
1392 toIfaceExpr (Var v) = toIfaceVar v
1393 toIfaceExpr (Lit l) = IfaceLit l
1394 toIfaceExpr (Type ty) = IfaceType (toIfaceType ty)
1395 toIfaceExpr (Lam x b) = IfaceLam (toIfaceBndr x) (toIfaceExpr b)
1396 toIfaceExpr (App f a) = toIfaceApp f [a]
1397 toIfaceExpr (Case s x ty as) = IfaceCase (toIfaceExpr s) (getFS x) (toIfaceType ty) (map toIfaceAlt as)
1398 toIfaceExpr (Let b e) = IfaceLet (toIfaceBind b) (toIfaceExpr e)
1399 toIfaceExpr (Cast e co) = IfaceCast (toIfaceExpr e) (toIfaceType co)
1400 toIfaceExpr (Note n e) = IfaceNote (toIfaceNote n) (toIfaceExpr e)
1402 ---------------------
1403 toIfaceNote (SCC cc) = IfaceSCC cc
1404 toIfaceNote InlineMe = IfaceInlineMe
1405 toIfaceNote (CoreNote s) = IfaceCoreNote s
1407 ---------------------
1408 toIfaceBind (NonRec b r) = IfaceNonRec (toIfaceLetBndr b) (toIfaceExpr r)
1409 toIfaceBind (Rec prs) = IfaceRec [(toIfaceLetBndr b, toIfaceExpr r) | (b,r) <- prs]
1411 ---------------------
1412 toIfaceAlt (c,bs,r) = (toIfaceCon c, map getFS bs, toIfaceExpr r)
1414 ---------------------
1415 toIfaceCon (DataAlt dc) | isTupleTyCon tc = IfaceTupleAlt (tupleTyConBoxity tc)
1416 | otherwise = IfaceDataAlt (getName dc)
1418 tc = dataConTyCon dc
1420 toIfaceCon (LitAlt l) = IfaceLitAlt l
1421 toIfaceCon DEFAULT = IfaceDefault
1423 ---------------------
1424 toIfaceApp (App f a) as = toIfaceApp f (a:as)
1425 toIfaceApp (Var v) as
1426 = case isDataConWorkId_maybe v of
1427 -- We convert the *worker* for tuples into IfaceTuples
1428 Just dc | isTupleTyCon tc && saturated
1429 -> IfaceTuple (tupleTyConBoxity tc) tup_args
1431 val_args = dropWhile isTypeArg as
1432 saturated = val_args `lengthIs` idArity v
1433 tup_args = map toIfaceExpr val_args
1434 tc = dataConTyCon dc
1436 other -> mkIfaceApps (toIfaceVar v) as
1438 toIfaceApp e as = mkIfaceApps (toIfaceExpr e) as
1440 mkIfaceApps f as = foldl (\f a -> IfaceApp f (toIfaceExpr a)) f as
1442 ---------------------
1443 toIfaceVar :: Id -> IfaceExpr
1445 | Just fcall <- isFCallId_maybe v = IfaceFCall fcall (toIfaceType (idType v))
1446 -- Foreign calls have special syntax
1447 | isExternalName name = IfaceExt name
1448 | Just (TickBox m ix) <- isTickBoxOp_maybe v
1450 | otherwise = IfaceLcl (getFS name)