2 % (c) The University of Glasgow 2006
3 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
8 -- The above warning supression flag is a temporary kludge.
9 -- While working on this module you are encouraged to remove it and fix
10 -- any warnings in the module. See
11 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
15 mkUsageInfo, -- Construct the usage info for a module
17 mkIface, -- Build a ModIface from a ModGuts,
18 -- including computing version information
20 writeIfaceFile, -- Write the interface file
22 checkOldIface, -- See if recompilation is required, by
23 -- comparing version information
25 tyThingToIfaceDecl -- Converting things to their Iface equivalents
29 -----------------------------------------------
30 MkIface.lhs deals with versioning
31 -----------------------------------------------
33 Here's the version-related info in an interface file
35 module Foo 8 -- module-version
36 3 -- export-list-version
38 Usages: -- Version info for what this compilation of Foo imported
39 Baz 3 -- Module version
40 [4] -- The export-list version if Foo depended on it
41 (g,2) -- Function and its version
42 (T,1) -- Type and its version
44 <version> f :: Int -> Int {- Unfolding: \x -> Wib.t[2] x -}
45 -- The [2] says that f's unfolding
46 -- mentions verison 2 of Wib.t
48 -----------------------------------------------
50 -----------------------------------------------
53 * In the mi_usages information in an interface, we record the
54 version number of each free variable of the module
56 * In mkIface, we compute the version number of each exported thing A.f
57 by comparing its A.f's info with its new info, and bumping its
58 version number if it differs. If A.f mentions B.g, and B.g's version
59 number has changed, then we count A.f as having changed too.
61 * In checkOldIface we compare the mi_usages for the module with
62 the actual version info for all each thing recorded in mi_usages
67 We count A.f as changing if its fixity changes
71 If a rule changes, we want to recompile any module that might be
72 affected by that rule. For non-orphan rules, this is relatively easy.
73 If module M defines f, and a rule for f, just arrange that the version
74 number for M.f changes if any of the rules for M.f change. Any module
75 that does not depend on M.f can't be affected by the rule-change
78 Orphan rules (ones whose 'head function' is not defined in M) are
79 harder. Here's what we do.
81 * We have a per-module orphan-rule version number which changes if
82 any orphan rule changes. (It's unaffected by non-orphan rules.)
84 * We record usage info for any orphan module 'below' this one,
85 giving the orphan-rule version number. We recompile if this
88 The net effect is that if an orphan rule changes, we recompile every
89 module above it. That's very conservative, but it's devilishly hard
90 to know what it might affect, so we just have to be conservative.
94 In an iface file we have
96 instance Eq a => Eq [a] = dfun29
99 We have a version number for dfun29, covering its unfolding
100 etc. Suppose we are compiling a module M that imports A only
101 indirectly. If typechecking M uses this instance decl, we record the
102 dependency on A.dfun29 as if it were a free variable of the module
103 (via the tcg_inst_usages accumulator). That means that A will appear
104 in M's usage list. If the shape of the instance declaration changes,
105 then so will dfun29's version, triggering a recompilation.
107 Adding an instance declaration, or changing an instance decl that is
108 not currently used, is more tricky. (This really only makes a
109 difference when we have overlapping instance decls, because then the
110 new instance decl might kick in to override the old one.) We handle
111 this in a very similar way that we handle rules above.
113 * For non-orphan instance decls, identify one locally-defined tycon/class
114 mentioned in the decl. Treat the instance decl as part of the defn of that
115 tycon/class, so that if the shape of the instance decl changes, so does the
116 tycon/class; that in turn will force recompilation of anything that uses
119 * For orphan instance decls, act the same way as for orphan rules.
120 Indeed, we use the same global orphan-rule version number.
124 mkUsageInfo figures out what the ``usage information'' for this
125 moudule is; that is, what it must record in its interface file as the
128 We produce a line for every module B below the module, A, currently being
131 to record the fact that A does import B indirectly. This is used to decide
132 to look to look for B.hi rather than B.hi-boot when compiling a module that
133 imports A. This line says that A imports B, but uses nothing in it.
134 So we'll get an early bale-out when compiling A if B's version changes.
136 The usage information records:
139 \item (a) anything reachable from its body code
140 \item (b) any module exported with a @module Foo@
141 \item (c) anything reachable from an exported item
144 Why (b)? Because if @Foo@ changes then this module's export list
145 will change, so we must recompile this module at least as far as
146 making a new interface file --- but in practice that means complete
149 Why (c)? Consider this:
151 module A( f, g ) where | module B( f ) where
152 import B( f ) | f = h 3
156 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
157 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
158 *identical* to what it was before. If anything about @B.f@ changes
159 than anyone who imports @A@ should be recompiled in case they use
160 @B.f@ (they'll get an early exit if they don't). So, if anything
161 about @B.f@ changes we'd better make sure that something in A.hi
162 changes, and the convenient way to do that is to record the version
163 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
164 complete recompiation of A, which is overkill but it's the only way to
165 write a new, slightly different, A.hi.
167 But the example is tricker. Even if @B.f@ doesn't change at all,
168 @B.h@ may do so, and this change may not be reflected in @f@'s version
169 number. But with -O, a module that imports A must be recompiled if
170 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
171 the occurrence of @B.f@ in the export list *just as if* it were in the
172 code of A, and thereby haul in all the stuff reachable from it.
174 *** Conclusion: if A mentions B.f in its export list,
175 behave just as if A mentioned B.f in its source code,
176 and slurp in B.f and all its transitive closure ***
178 [NB: If B was compiled with -O, but A isn't, we should really *still*
179 haul in all the unfoldings for B, in case the module that imports A *is*
180 compiled with -O. I think this is the case.]
184 #include "HsVersions.h"
217 import PackageConfig hiding ( Version )
219 import BasicTypes hiding ( SuccessFlag(..) )
221 import Util hiding ( eqListBy )
232 %************************************************************************
234 \subsection{Completing an interface}
236 %************************************************************************
240 -> Maybe ModIface -- The old interface, if we have it
241 -> ModGuts -- Usages, deprecations, etc
242 -> ModDetails -- The trimmed, tidied interface
243 -> IO (ModIface, -- The new one, complete with decls and versions
244 Bool) -- True <=> there was an old Iface, and the new one
245 -- is identical, so no need to write it
247 mkIface hsc_env maybe_old_iface
248 (ModGuts{ mg_module = this_mod,
252 mg_rdr_env = rdr_env,
253 mg_fix_env = fix_env,
254 mg_deprecs = src_deprecs,
255 mg_hpc_info = hpc_info })
256 (ModDetails{ md_insts = insts,
257 md_fam_insts = fam_insts,
259 md_vect_info = vect_info,
261 md_exports = exports })
263 -- NB: notice that mkIface does not look at the bindings
264 -- only at the TypeEnv. The previous Tidy phase has
265 -- put exactly the info into the TypeEnv that we want
266 -- to expose in the interface
268 = do {eps <- hscEPS hsc_env
269 ; let { entities = typeEnvElts type_env ;
270 decls = [ tyThingToIfaceDecl entity
271 | entity <- entities,
272 let name = getName entity,
273 not (isImplicitTyThing entity),
274 -- No implicit Ids and class tycons in the interface file
275 not (isWiredInName name),
276 -- Nor wired-in things; the compiler knows about them anyhow
277 nameIsLocalOrFrom this_mod name ]
278 -- Sigh: see Note [Root-main Id] in TcRnDriver
280 ; fixities = [(occ,fix) | FixItem occ fix <- nameEnvElts fix_env]
281 ; deprecs = src_deprecs
282 ; iface_rules = map (coreRuleToIfaceRule this_mod) rules
283 ; iface_insts = map instanceToIfaceInst insts
284 ; iface_fam_insts = map famInstToIfaceFamInst fam_insts
285 ; iface_vect_info = flattenVectInfo vect_info
287 ; intermediate_iface = ModIface {
288 mi_module = this_mod,
292 mi_exports = mkIfaceExports exports,
294 -- Sort these lexicographically, so that
295 -- the result is stable across compilations
296 mi_insts = sortLe le_inst iface_insts,
297 mi_fam_insts= sortLe le_fam_inst iface_fam_insts,
298 mi_rules = sortLe le_rule iface_rules,
300 mi_vect_info = iface_vect_info,
302 mi_fixities = fixities,
303 mi_deprecs = deprecs,
304 mi_globals = Just rdr_env,
306 -- Left out deliberately: filled in by addVersionInfo
307 mi_mod_vers = initialVersion,
308 mi_exp_vers = initialVersion,
309 mi_rule_vers = initialVersion,
310 mi_orphan = False, -- Always set by addVersionInfo, but
311 -- it's a strict field, so we can't omit it.
312 mi_finsts = False, -- Ditto
313 mi_decls = deliberatelyOmitted "decls",
314 mi_ver_fn = deliberatelyOmitted "ver_fn",
315 mi_hpc = isHpcUsed hpc_info,
317 -- And build the cached values
318 mi_dep_fn = mkIfaceDepCache deprecs,
319 mi_fix_fn = mkIfaceFixCache fixities }
321 -- Add version information
322 ; ext_ver_fn = mkParentVerFun hsc_env eps
323 ; (new_iface, no_change_at_all, pp_diffs, pp_orphs)
324 = {-# SCC "versioninfo" #-}
325 addVersionInfo ext_ver_fn maybe_old_iface
326 intermediate_iface decls
330 ; when (isJust pp_orphs && dopt Opt_WarnOrphans dflags)
331 (printDump (expectJust "mkIface" pp_orphs))
332 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
333 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
334 (pprModIface new_iface)
336 ; return (new_iface, no_change_at_all) }
338 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
339 i1 `le_inst` i2 = ifDFun i1 `le_occ` ifDFun i2
340 i1 `le_fam_inst` i2 = ifFamInstTcName i1 `le_occ` ifFamInstTcName i2
342 le_occ :: Name -> Name -> Bool
343 -- Compare lexicographically by OccName, *not* by unique, because
344 -- the latter is not stable across compilations
345 le_occ n1 n2 = nameOccName n1 <= nameOccName n2
347 dflags = hsc_dflags hsc_env
348 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
349 ifFamInstTcName = ifaceTyConName . ifFamInstTyCon
351 flattenVectInfo (VectInfo { vectInfoVar = vVar
352 , vectInfoTyCon = vTyCon
355 ifaceVectInfoVar = [ Var.varName v
356 | (v, _) <- varEnvElts vVar],
357 ifaceVectInfoTyCon = [ tyConName t
358 | (t, t_v) <- nameEnvElts vTyCon
360 ifaceVectInfoTyConReuse = [ tyConName t
361 | (t, t_v) <- nameEnvElts vTyCon
365 -----------------------------
366 writeIfaceFile :: DynFlags -> ModLocation -> ModIface -> IO ()
367 writeIfaceFile dflags location new_iface
368 = do createDirectoryHierarchy (directoryOf hi_file_path)
369 writeBinIface dflags hi_file_path new_iface
370 where hi_file_path = ml_hi_file location
373 -- -----------------------------------------------------------------------------
374 -- Look up parents and versions of Names
376 -- This is like a global version of the mi_ver_fn field in each ModIface.
377 -- Given a Name, it finds the ModIface, and then uses mi_ver_fn to get
378 -- the parent and version info.
381 :: HscEnv -- needed to look up versions
382 -> ExternalPackageState -- ditto
383 -> (Name -> (OccName,Version))
384 mkParentVerFun hsc_env eps
387 mod = nameModule name
388 occ = nameOccName name
389 iface = lookupIfaceByModule (hsc_dflags hsc_env) hpt pit mod `orElse`
390 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
392 mi_ver_fn iface occ `orElse`
393 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
395 hpt = hsc_HPT hsc_env
398 -----------------------------------------------------------------------------
399 -- Compute version numbers for local decls
402 :: (Name -> (OccName,Version)) -- lookup parents and versions of names
403 -> Maybe ModIface -- The old interface, read from M.hi
404 -> ModIface -- The new interface (lacking decls)
405 -> [IfaceDecl] -- The new decls
406 -> (ModIface, -- Updated interface
407 Bool, -- True <=> no changes at all; no need to write Iface
409 Maybe SDoc) -- Warnings about orphans
411 addVersionInfo ver_fn Nothing new_iface new_decls
412 -- No old interface, so definitely write a new one!
413 = (new_iface { mi_orphan = not (null orph_insts && null orph_rules)
414 , mi_finsts = not . null $ mi_fam_insts new_iface
415 , mi_decls = [(initialVersion, decl) | decl <- new_decls]
416 , mi_ver_fn = mkIfaceVerCache (zip (repeat initialVersion)
420 ptext SLIT("No old interface file"),
421 pprOrphans orph_insts orph_rules)
423 orph_insts = filter (isNothing . ifInstOrph) (mi_insts new_iface)
424 orph_rules = filter (isNothing . ifRuleOrph) (mi_rules new_iface)
426 addVersionInfo ver_fn (Just old_iface@(ModIface {
427 mi_mod_vers = old_mod_vers,
428 mi_exp_vers = old_exp_vers,
429 mi_rule_vers = old_rule_vers,
430 mi_decls = old_decls,
431 mi_ver_fn = old_decl_vers,
432 mi_fix_fn = old_fixities }))
433 new_iface@(ModIface { mi_fix_fn = new_fixities })
436 = (old_iface, True, ptext SLIT("Interface file unchanged"), pp_orphs)
438 = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
439 nest 2 pp_diffs], pp_orphs)
441 final_iface = new_iface {
442 mi_mod_vers = bump_unless no_output_change old_mod_vers,
443 mi_exp_vers = bump_unless no_export_change old_exp_vers,
444 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
445 mi_orphan = not (null new_orph_rules && null new_orph_insts),
446 mi_finsts = not . null $ mi_fam_insts new_iface,
447 mi_decls = decls_w_vers,
448 mi_ver_fn = mkIfaceVerCache decls_w_vers }
450 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
453 (old_non_orph_insts, old_orph_insts) =
454 mkOrphMap ifInstOrph (mi_insts old_iface)
455 (new_non_orph_insts, new_orph_insts) =
456 mkOrphMap ifInstOrph (mi_insts new_iface)
457 old_fam_insts = mi_fam_insts old_iface
458 new_fam_insts = mi_fam_insts new_iface
459 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
460 (lookupOccEnv old_non_orph_insts occ)
461 (lookupOccEnv new_non_orph_insts occ)
463 (old_non_orph_rules, old_orph_rules) =
464 mkOrphMap ifRuleOrph (mi_rules old_iface)
465 (new_non_orph_rules, new_orph_rules) =
466 mkOrphMap ifRuleOrph (mi_rules new_iface)
467 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
468 (lookupOccEnv old_non_orph_rules occ)
469 (lookupOccEnv new_non_orph_rules occ)
471 -- Computing what changed
472 no_output_change = no_decl_change && no_rule_change &&
473 no_export_change && no_deprec_change
474 no_export_change = mi_exports new_iface == mi_exports old_iface
476 no_decl_change = isEmptyOccSet changed_occs
477 no_rule_change = not (changedWrtNames changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
478 || changedWrtNames changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts)
479 || changedWrtNames changed_occs (eqListBy eqIfFamInst old_fam_insts new_fam_insts))
480 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
482 -- If the usages havn't changed either, we don't need to write the interface file
483 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
484 mi_deps new_iface == mi_deps old_iface &&
485 mi_hpc new_iface == mi_hpc old_iface
486 no_change_at_all = no_output_change && no_other_changes
488 pp_diffs = vcat [pp_change no_export_change "Export list"
489 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
490 pp_change no_rule_change "Rules"
491 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
492 pp_change no_deprec_change "Deprecations" empty,
493 pp_change no_other_changes "Usages" empty,
495 pp_change True what info = empty
496 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
499 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
500 same_fixity n = bool (old_fixities n == new_fixities n)
503 -- Adding version info
504 new_version = bumpVersion old_mod_vers
505 -- Start from the old module version, not from
506 -- zero so that if you remove f, and then add
507 -- it again, you don't thereby reduce f's
510 add_vers decl | occ `elemOccSet` changed_occs = new_version
511 | otherwise = snd (expectJust "add_vers" (old_decl_vers occ))
512 -- If it's unchanged, there jolly well
513 where -- should be an old version number
517 -- Deciding which declarations have changed
519 -- For each local decl, the IfaceEq gives the list of things that
520 -- must be unchanged for the declaration as a whole to be unchanged.
521 eq_info :: [(OccName, IfaceEq)]
522 eq_info = map check_eq new_decls
524 | Just old_decl <- lookupOccEnv old_decl_env occ
525 = (occ, new_decl `eqIfDecl` old_decl &&& eq_indirects new_decl)
526 | otherwise {- No corresponding old decl -}
529 occ = ifName new_decl
531 eq_indirects :: IfaceDecl -> IfaceEq
532 -- When seeing if two decls are the same, remember to
533 -- check whether any relevant fixity or rules have changed
534 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
535 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
536 = same_insts cls_occ &&&
537 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
538 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
539 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
540 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
541 eq_indirects other = Equal -- Synonyms and foreign declarations
543 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
544 eq_ind_occ occ = same_fixity occ &&& same_rules occ
545 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
547 -- The Occs of declarations that changed.
548 changed_occs :: OccSet
549 changed_occs = computeChangedOccs ver_fn (mi_module new_iface)
550 (mi_usages old_iface) eq_info
554 pp_decl_diffs :: SDoc -- Nothing => no changes
556 | isEmptyOccSet changed_occs = empty
558 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
559 ptext SLIT("Version change for these decls:"),
560 nest 2 (vcat (map show_change new_decls))]
562 eq_env = mkOccEnv eq_info
564 | not (occ `elemOccSet` changed_occs) = empty
566 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
569 occ = ifName new_decl
570 why = case lookupOccEnv eq_env occ of
571 Just (EqBut names) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:") <> ppr names,
572 nest 2 (braces (fsep (map ppr (occSetElts
573 (occs `intersectOccSet` changed_occs)))))]
574 where occs = mkOccSet (map nameOccName (nameSetToList names))
576 | Just old_decl <- lookupOccEnv old_decl_env occ
577 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
578 ptext SLIT("New:") <+> ppr new_decl]
580 -> ppr occ <+> ptext SLIT("only in new interface")
581 other -> pprPanic "MkIface.show_change" (ppr occ)
583 pp_orphs = pprOrphans new_orph_insts new_orph_rules
586 pprOrphans insts rules
587 | null insts && null rules = Nothing
590 if null insts then empty else
591 hang (ptext SLIT("Warning: orphan instances:"))
592 2 (vcat (map ppr insts)),
593 if null rules then empty else
594 hang (ptext SLIT("Warning: orphan rules:"))
595 2 (vcat (map ppr rules))
599 :: (Name -> (OccName,Version)) -- get parents and versions
600 -> Module -- This module
601 -> [Usage] -- Usages from old iface
602 -> [(OccName, IfaceEq)] -- decl names, equality conditions
603 -> OccSet -- set of things that have changed
604 computeChangedOccs ver_fn this_module old_usages eq_info
605 = foldl add_changes emptyOccSet (stronglyConnComp edges)
608 -- return True if an external name has changed
609 name_changed :: Name -> Bool
611 | Just ents <- lookupUFM usg_modmap (moduleName mod)
612 = case lookupUFM ents parent_occ of
613 Nothing -> pprPanic "computeChangedOccs" (ppr nm)
614 Just v -> v < new_version
615 | otherwise = False -- must be in another package
618 (parent_occ, new_version) = ver_fn nm
620 -- Turn the usages from the old ModIface into a mapping
621 usg_modmap = listToUFM [ (usg_mod usg, listToUFM (usg_entities usg))
622 | usg <- old_usages ]
624 get_local_eq_info :: GenIfaceEq NameSet -> GenIfaceEq OccSet
625 get_local_eq_info Equal = Equal
626 get_local_eq_info NotEqual = NotEqual
627 get_local_eq_info (EqBut ns) = foldNameSet f Equal ns
628 where f name eq | nameModule name == this_module =
629 EqBut (unitOccSet (nameOccName name)) `and_occifeq` eq
630 | name_changed name = NotEqual
633 local_eq_infos = mapSnd get_local_eq_info eq_info
635 edges :: [((OccName, OccIfaceEq), Unique, [Unique])]
636 edges = [ (node, getUnique occ, map getUnique occs)
637 | node@(occ, iface_eq) <- local_eq_infos
638 , let occs = case iface_eq of
639 EqBut occ_set -> occSetElts occ_set
642 -- Changes in declarations
643 add_changes :: OccSet -> SCC (OccName, OccIfaceEq) -> OccSet
644 add_changes so_far (AcyclicSCC (occ, iface_eq))
645 | changedWrt so_far iface_eq -- This one has changed
646 = extendOccSet so_far occ
647 add_changes so_far (CyclicSCC pairs)
648 | changedWrt so_far (foldr1 and_occifeq iface_eqs)
649 -- One of this group has changed
650 = extendOccSetList so_far occs
651 where (occs, iface_eqs) = unzip pairs
652 add_changes so_far other = so_far
654 type OccIfaceEq = GenIfaceEq OccSet
656 changedWrt :: OccSet -> OccIfaceEq -> Bool
657 changedWrt so_far Equal = False
658 changedWrt so_far NotEqual = True
659 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
661 changedWrtNames :: OccSet -> IfaceEq -> Bool
662 changedWrtNames so_far Equal = False
663 changedWrtNames so_far NotEqual = True
664 changedWrtNames so_far (EqBut kids) =
665 so_far `intersectsOccSet` mkOccSet (map nameOccName (nameSetToList kids))
667 and_occifeq :: OccIfaceEq -> OccIfaceEq -> OccIfaceEq
668 Equal `and_occifeq` x = x
669 NotEqual `and_occifeq` x = NotEqual
670 EqBut nms `and_occifeq` Equal = EqBut nms
671 EqBut nms `and_occifeq` NotEqual = NotEqual
672 EqBut nms1 `and_occifeq` EqBut nms2 = EqBut (nms1 `unionOccSets` nms2)
674 ----------------------
675 -- mkOrphMap partitions instance decls or rules into
676 -- (a) an OccEnv for ones that are not orphans,
677 -- mapping the local OccName to a list of its decls
678 -- (b) a list of orphan decls
679 mkOrphMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
680 -- Nothing for an orphan decl
681 -> [decl] -- Sorted into canonical order
682 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
683 -- each sublist in canonical order
684 [decl]) -- Orphan decls; in canonical order
685 mkOrphMap get_key decls
686 = foldl go (emptyOccEnv, []) decls
688 go (non_orphs, orphs) d
689 | Just occ <- get_key d
690 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
691 | otherwise = (non_orphs, d:orphs)
693 ----------------------
694 bump_unless :: Bool -> Version -> Version
695 bump_unless True v = v -- True <=> no change
696 bump_unless False v = bumpVersion v
700 %*********************************************************
702 \subsection{Keeping track of what we've slurped, and version numbers}
704 %*********************************************************
708 mkUsageInfo :: HscEnv
709 -> ModuleEnv (Module, [(ModuleName, Bool, SrcSpan)])
710 -> [(ModuleName, IsBootInterface)]
711 -> NameSet -> IO [Usage]
712 mkUsageInfo hsc_env dir_imp_mods dep_mods used_names
713 = do { eps <- hscEPS hsc_env
714 ; let usages = mk_usage_info (eps_PIT eps) hsc_env
715 dir_imp_mods dep_mods used_names
716 ; usages `seqList` return usages }
717 -- seq the list of Usages returned: occasionally these
718 -- don't get evaluated for a while and we can end up hanging on to
719 -- the entire collection of Ifaces.
721 mk_usage_info :: PackageIfaceTable
723 -> ModuleEnv (Module, [(ModuleName, Bool, SrcSpan)])
724 -> [(ModuleName, IsBootInterface)]
727 mk_usage_info pit hsc_env dir_imp_mods dep_mods used_names
728 = mapCatMaybes mkUsage dep_mods
729 -- ToDo: do we need to sort into canonical order?
731 hpt = hsc_HPT hsc_env
732 dflags = hsc_dflags hsc_env
734 -- ent_map groups together all the things imported and used
735 -- from a particular module in this package
736 ent_map :: ModuleEnv [OccName]
737 ent_map = foldNameSet add_mv emptyModuleEnv used_names
739 | isWiredInName name = mv_map -- ignore wired-in names
741 = case nameModule_maybe name of
742 Nothing -> mv_map -- ignore internal names
743 Just mod -> extendModuleEnv_C add_item mv_map mod [occ]
745 occ = nameOccName name
746 add_item occs _ = occ:occs
748 depend_on_exports mod = case lookupModuleEnv dir_imp_mods mod of
749 Just (_, xs) -> any (\(_, no_imp, _) -> not no_imp) xs
752 -- We want to create a Usage for a home module if
753 -- a) we used something from; has something in used_names
754 -- b) we imported all of it, even if we used nothing from it
755 -- (need to recompile if its export list changes: export_vers)
756 -- c) is a home-package orphan or family-instance module (need to
757 -- recompile if its instance decls change: rules_vers)
758 mkUsage :: (ModuleName, IsBootInterface) -> Maybe Usage
759 mkUsage (mod_name, _)
760 | isNothing maybe_iface -- We can't depend on it if we didn't
761 || (null used_occs -- load its interface.
762 && isNothing export_vers
765 = Nothing -- Record no usage info
768 = Just (Usage { usg_name = mod_name,
770 usg_exports = export_vers,
771 usg_entities = fmToList ent_vers,
772 usg_rules = rules_vers })
774 maybe_iface = lookupIfaceByModule dflags hpt pit mod
775 -- In one-shot mode, the interfaces for home-package
776 -- modules accumulate in the PIT not HPT. Sigh.
778 mod = mkModule (thisPackage dflags) mod_name
780 Just iface = maybe_iface
781 orphan_mod = mi_orphan iface
782 finsts_mod = mi_finsts iface
783 version_env = mi_ver_fn iface
784 mod_vers = mi_mod_vers iface
785 rules_vers = mi_rule_vers iface
786 export_vers | depend_on_exports mod = Just (mi_exp_vers iface)
787 | otherwise = Nothing
789 used_occs = lookupModuleEnv ent_map mod `orElse` []
791 -- Making a FiniteMap here ensures that (a) we remove duplicates
792 -- when we have usages on several subordinates of a single parent,
793 -- and (b) that the usages emerge in a canonical order, which
794 -- is why we use FiniteMap rather than OccEnv: FiniteMap works
795 -- using Ord on the OccNames, which is a lexicographic ordering.
796 ent_vers :: FiniteMap OccName Version
797 ent_vers = listToFM (map lookup_occ used_occs)
800 case version_env occ of
801 Nothing -> pprTrace "hmm, strange" (ppr mod <+> ppr occ) $
802 (occ, initialVersion) -- does this ever happen?
803 Just (parent, version) -> (parent, version)
807 mkIfaceExports :: [AvailInfo]
808 -> [(Module, [GenAvailInfo OccName])]
809 -- Group by module and sort by occurrence
810 -- This keeps the list in canonical order
811 mkIfaceExports exports
812 = [ (mod, eltsFM avails)
813 | (mod, avails) <- fmToList groupFM
816 -- Group by the module where the exported entities are defined
817 -- (which may not be the same for all Names in an Avail)
818 -- Deliberately use FiniteMap rather than UniqFM so we
819 -- get a canonical ordering
820 groupFM :: ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
821 groupFM = foldl add emptyModuleEnv exports
823 add_one :: ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
824 -> Module -> GenAvailInfo OccName
825 -> ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
826 add_one env mod avail
827 = extendModuleEnv_C plusFM env mod
828 (unitFM (occNameFS (availName avail)) avail)
830 -- NB: we should not get T(X) and T(Y) in the export list
831 -- else the plusFM will simply discard one! They
832 -- should have been combined by now.
834 = add_one env (nameModule n) (Avail (nameOccName n))
836 add env (AvailTC tc ns)
837 = foldl add_for_mod env mods
839 tc_occ = nameOccName tc
840 mods = nub (map nameModule ns)
841 -- Usually just one, but see Note [Original module]
844 = add_one env mod (AvailTC tc_occ (sort names_from_mod))
845 -- NB. sort the children, we need a canonical order
847 names_from_mod = [nameOccName n | n <- ns, nameModule n == mod]
850 Note [Orignal module]
851 ~~~~~~~~~~~~~~~~~~~~~
853 module X where { data family T }
854 module Y( T(..) ) where { import X; data instance T Int = MkT Int }
855 The exported Avail from Y will look like
858 - only MkT is brought into scope by the data instance;
859 - but the parent (used for grouping and naming in T(..) exports) is X.T
860 - and in this case we export X.T too
862 In the result of MkIfaceExports, the names are grouped by defining module,
863 so we may need to split up a single Avail into multiple ones.
866 %************************************************************************
868 Load the old interface file for this module (unless
869 we have it aleady), and check whether it is up to date
872 %************************************************************************
875 checkOldIface :: HscEnv
877 -> Bool -- Source unchanged
878 -> Maybe ModIface -- Old interface from compilation manager, if any
879 -> IO (RecompileRequired, Maybe ModIface)
881 checkOldIface hsc_env mod_summary source_unchanged maybe_iface
882 = do { showPass (hsc_dflags hsc_env)
883 ("Checking old interface for " ++
884 showSDoc (ppr (ms_mod mod_summary))) ;
886 ; initIfaceCheck hsc_env $
887 check_old_iface hsc_env mod_summary source_unchanged maybe_iface
890 check_old_iface hsc_env mod_summary source_unchanged maybe_iface
891 = do -- CHECK WHETHER THE SOURCE HAS CHANGED
892 { ifM (not source_unchanged)
893 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
895 -- If the source has changed and we're in interactive mode, avoid reading
896 -- an interface; just return the one we might have been supplied with.
897 ; let dflags = hsc_dflags hsc_env
898 ; if not (isObjectTarget (hscTarget dflags)) && not source_unchanged then
899 return (outOfDate, maybe_iface)
901 case maybe_iface of {
902 Just old_iface -> do -- Use the one we already have
903 { traceIf (text "We already have the old interface for" <+> ppr (ms_mod mod_summary))
904 ; recomp <- checkVersions hsc_env source_unchanged mod_summary old_iface
905 ; return (recomp, Just old_iface) }
909 -- Try and read the old interface for the current module
910 -- from the .hi file left from the last time we compiled it
911 { let iface_path = msHiFilePath mod_summary
912 ; read_result <- readIface (ms_mod mod_summary) iface_path False
913 ; case read_result of {
914 Failed err -> do -- Old interface file not found, or garbled; give up
915 { traceIf (text "FYI: cannot read old interface file:"
917 ; return (outOfDate, Nothing) }
919 ; Succeeded iface -> do
921 -- We have got the old iface; check its versions
922 { traceIf (text "Read the interface file" <+> text iface_path)
923 ; recomp <- checkVersions hsc_env source_unchanged mod_summary iface
924 ; returnM (recomp, Just iface)
929 @recompileRequired@ is called from the HscMain. It checks whether
930 a recompilation is required. It needs access to the persistent state,
931 finder, etc, because it may have to load lots of interface files to
932 check their versions.
935 type RecompileRequired = Bool
936 upToDate = False -- Recompile not required
937 outOfDate = True -- Recompile required
939 checkVersions :: HscEnv
940 -> Bool -- True <=> source unchanged
942 -> ModIface -- Old interface
943 -> IfG RecompileRequired
944 checkVersions hsc_env source_unchanged mod_summary iface
945 | not source_unchanged
948 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
949 ppr (mi_module iface) <> colon)
951 ; recomp <- checkDependencies hsc_env mod_summary iface
952 ; if recomp then return outOfDate else do {
954 -- Source code unchanged and no errors yet... carry on
956 -- First put the dependent-module info, read from the old interface, into the envt,
957 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
959 -- It's just temporary because either the usage check will succeed
960 -- (in which case we are done with this module) or it'll fail (in which
961 -- case we'll compile the module from scratch anyhow).
963 -- We do this regardless of compilation mode, although in --make mode
964 -- all the dependent modules should be in the HPT already, so it's
966 updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
968 ; let this_pkg = thisPackage (hsc_dflags hsc_env)
969 ; checkList [checkModUsage this_pkg u | u <- mi_usages iface]
972 -- This is a bit of a hack really
973 mod_deps :: ModuleNameEnv (ModuleName, IsBootInterface)
974 mod_deps = mkModDeps (dep_mods (mi_deps iface))
977 -- If the direct imports of this module are resolved to targets that
978 -- are not among the dependencies of the previous interface file,
979 -- then we definitely need to recompile. This catches cases like
980 -- - an exposed package has been upgraded
981 -- - we are compiling with different package flags
982 -- - a home module that was shadowing a package module has been removed
983 -- - a new home module has been added that shadows a package module
986 -- Returns True if recompilation is required.
987 checkDependencies :: HscEnv -> ModSummary -> ModIface -> IfG RecompileRequired
988 checkDependencies hsc_env summary iface
989 = orM (map dep_missing (ms_imps summary ++ ms_srcimps summary))
991 prev_dep_mods = dep_mods (mi_deps iface)
992 prev_dep_pkgs = dep_pkgs (mi_deps iface)
994 this_pkg = thisPackage (hsc_dflags hsc_env)
996 orM = foldr f (return False)
997 where f m rest = do b <- m; if b then return True else rest
999 dep_missing (L _ mod) = do
1000 find_res <- ioToIOEnv $ findImportedModule hsc_env mod Nothing
1004 -> if moduleName mod `notElem` map fst prev_dep_mods
1005 then do traceHiDiffs $
1006 text "imported module " <> quotes (ppr mod) <>
1007 text " not among previous dependencies"
1012 -> if pkg `notElem` prev_dep_pkgs
1013 then do traceHiDiffs $
1014 text "imported module " <> quotes (ppr mod) <>
1015 text " is from package " <> quotes (ppr pkg) <>
1016 text ", which is not among previous dependencies"
1020 where pkg = modulePackageId mod
1021 _otherwise -> return outOfDate
1023 checkModUsage :: PackageId ->Usage -> IfG RecompileRequired
1024 -- Given the usage information extracted from the old
1025 -- M.hi file for the module being compiled, figure out
1026 -- whether M needs to be recompiled.
1028 checkModUsage this_pkg (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
1029 usg_rules = old_rule_vers,
1030 usg_exports = maybe_old_export_vers,
1031 usg_entities = old_decl_vers })
1032 = -- Load the imported interface is possible
1034 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
1036 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
1039 mod = mkModule this_pkg mod_name
1041 loadInterface doc_str mod ImportBySystem `thenM` \ mb_iface ->
1042 -- Load the interface, but don't complain on failure;
1043 -- Instead, get an Either back which we can test
1046 Failed exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
1048 -- Couldn't find or parse a module mentioned in the
1049 -- old interface file. Don't complain -- it might just be that
1050 -- the current module doesn't need that import and it's been deleted
1054 new_mod_vers = mi_mod_vers iface
1055 new_decl_vers = mi_ver_fn iface
1056 new_export_vers = mi_exp_vers iface
1057 new_rule_vers = mi_rule_vers iface
1060 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
1061 if not recompile then
1065 -- CHECK EXPORT LIST
1066 if checkExportList maybe_old_export_vers new_export_vers then
1067 out_of_date_vers (ptext SLIT(" Export list changed"))
1068 (expectJust "checkModUsage" maybe_old_export_vers)
1073 if old_rule_vers /= new_rule_vers then
1074 out_of_date_vers (ptext SLIT(" Rules changed"))
1075 old_rule_vers new_rule_vers
1078 -- CHECK ITEMS ONE BY ONE
1079 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
1081 returnM outOfDate -- This one failed, so just bail out now
1083 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
1086 ------------------------
1087 checkModuleVersion old_mod_vers new_mod_vers
1088 | new_mod_vers == old_mod_vers
1089 = up_to_date (ptext SLIT("Module version unchanged"))
1092 = out_of_date_vers (ptext SLIT(" Module version has changed"))
1093 old_mod_vers new_mod_vers
1095 ------------------------
1096 checkExportList Nothing new_vers = upToDate
1097 checkExportList (Just v) new_vers = v /= new_vers
1099 ------------------------
1100 checkEntityUsage new_vers (name,old_vers)
1101 = case new_vers name of
1103 Nothing -> -- We used it before, but it ain't there now
1104 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
1106 Just (_, new_vers) -- It's there, but is it up to date?
1107 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
1109 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
1112 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
1113 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
1114 out_of_date_vers msg old_vers new_vers
1115 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
1117 ----------------------
1118 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
1119 -- This helper is used in two places
1120 checkList [] = returnM upToDate
1121 checkList (check:checks) = check `thenM` \ recompile ->
1128 %************************************************************************
1130 Converting things to their Iface equivalents
1132 %************************************************************************
1135 tyThingToIfaceDecl :: TyThing -> IfaceDecl
1136 -- Assumption: the thing is already tidied, so that locally-bound names
1137 -- (lambdas, for-alls) already have non-clashing OccNames
1138 -- Reason: Iface stuff uses OccNames, and the conversion here does
1139 -- not do tidying on the way
1140 tyThingToIfaceDecl (AnId id)
1141 = IfaceId { ifName = getOccName id,
1142 ifType = toIfaceType (idType id),
1145 info = case toIfaceIdInfo (idInfo id) of
1147 items -> HasInfo items
1149 tyThingToIfaceDecl (AClass clas)
1150 = IfaceClass { ifCtxt = toIfaceContext sc_theta,
1151 ifName = getOccName clas,
1152 ifTyVars = toIfaceTvBndrs clas_tyvars,
1153 ifFDs = map toIfaceFD clas_fds,
1154 ifATs = map (tyThingToIfaceDecl . ATyCon) clas_ats,
1155 ifSigs = map toIfaceClassOp op_stuff,
1156 ifRec = boolToRecFlag (isRecursiveTyCon tycon) }
1158 (clas_tyvars, clas_fds, sc_theta, _, clas_ats, op_stuff)
1159 = classExtraBigSig clas
1160 tycon = classTyCon clas
1162 toIfaceClassOp (sel_id, def_meth)
1163 = ASSERT(sel_tyvars == clas_tyvars)
1164 IfaceClassOp (getOccName sel_id) def_meth (toIfaceType op_ty)
1166 -- Be careful when splitting the type, because of things
1167 -- like class Foo a where
1168 -- op :: (?x :: String) => a -> a
1169 -- and class Baz a where
1170 -- op :: (Ord a) => a -> a
1171 (sel_tyvars, rho_ty) = splitForAllTys (idType sel_id)
1172 op_ty = funResultTy rho_ty
1174 toIfaceFD (tvs1, tvs2) = (map getFS tvs1, map getFS tvs2)
1176 tyThingToIfaceDecl (ATyCon tycon)
1178 = IfaceSyn { ifName = getOccName tycon,
1179 ifTyVars = toIfaceTvBndrs tyvars,
1180 ifOpenSyn = syn_isOpen,
1181 ifSynRhs = toIfaceType syn_tyki,
1182 ifFamInst = famInstToIface (tyConFamInst_maybe tycon)
1186 = IfaceData { ifName = getOccName tycon,
1187 ifTyVars = toIfaceTvBndrs tyvars,
1188 ifCtxt = toIfaceContext (tyConStupidTheta tycon),
1189 ifCons = ifaceConDecls (algTyConRhs tycon),
1190 ifRec = boolToRecFlag (isRecursiveTyCon tycon),
1191 ifGadtSyntax = isGadtSyntaxTyCon tycon,
1192 ifGeneric = tyConHasGenerics tycon,
1193 ifFamInst = famInstToIface (tyConFamInst_maybe tycon)}
1195 | isForeignTyCon tycon
1196 = IfaceForeign { ifName = getOccName tycon,
1197 ifExtName = tyConExtName tycon }
1199 | otherwise = pprPanic "toIfaceDecl" (ppr tycon)
1201 tyvars = tyConTyVars tycon
1202 (syn_isOpen, syn_tyki) = case synTyConRhs tycon of
1203 OpenSynTyCon ki _ -> (True , ki)
1204 SynonymTyCon ty -> (False, ty)
1206 ifaceConDecls (NewTyCon { data_con = con }) =
1207 IfNewTyCon (ifaceConDecl con)
1208 ifaceConDecls (DataTyCon { data_cons = cons }) =
1209 IfDataTyCon (map ifaceConDecl cons)
1210 ifaceConDecls OpenTyCon {} = IfOpenDataTyCon
1211 ifaceConDecls AbstractTyCon = IfAbstractTyCon
1212 -- The last case happens when a TyCon has been trimmed during tidying
1213 -- Furthermore, tyThingToIfaceDecl is also used
1214 -- in TcRnDriver for GHCi, when browsing a module, in which case the
1215 -- AbstractTyCon case is perfectly sensible.
1217 ifaceConDecl data_con
1218 = IfCon { ifConOcc = getOccName (dataConName data_con),
1219 ifConInfix = dataConIsInfix data_con,
1220 ifConUnivTvs = toIfaceTvBndrs (dataConUnivTyVars data_con),
1221 ifConExTvs = toIfaceTvBndrs (dataConExTyVars data_con),
1222 ifConEqSpec = to_eq_spec (dataConEqSpec data_con),
1223 ifConCtxt = toIfaceContext (dataConEqTheta data_con ++ dataConDictTheta data_con),
1224 ifConArgTys = map toIfaceType (dataConOrigArgTys data_con),
1225 ifConFields = map getOccName
1226 (dataConFieldLabels data_con),
1227 ifConStricts = dataConStrictMarks data_con }
1229 to_eq_spec spec = [(getOccName tv, toIfaceType ty) | (tv,ty) <- spec]
1231 famInstToIface Nothing = Nothing
1232 famInstToIface (Just (famTyCon, instTys)) =
1233 Just (toIfaceTyCon famTyCon, map toIfaceType instTys)
1235 tyThingToIfaceDecl (ADataCon dc)
1236 = pprPanic "toIfaceDecl" (ppr dc) -- Should be trimmed out earlier
1239 getFS x = occNameFS (getOccName x)
1241 --------------------------
1242 instanceToIfaceInst :: Instance -> IfaceInst
1243 instanceToIfaceInst ispec@(Instance { is_dfun = dfun_id, is_flag = oflag,
1244 is_cls = cls_name, is_tcs = mb_tcs })
1245 = ASSERT( cls_name == className cls )
1246 IfaceInst { ifDFun = dfun_name,
1248 ifInstCls = cls_name,
1249 ifInstTys = map do_rough mb_tcs,
1252 do_rough Nothing = Nothing
1253 do_rough (Just n) = Just (toIfaceTyCon_name n)
1255 dfun_name = idName dfun_id
1256 mod = nameModule dfun_name
1257 is_local name = nameIsLocalOrFrom mod name
1259 -- Compute orphanhood. See Note [Orphans] in IfaceSyn
1260 (_, _, cls, tys) = tcSplitDFunTy (idType dfun_id)
1261 -- Slightly awkward: we need the Class to get the fundeps
1262 (tvs, fds) = classTvsFds cls
1263 arg_names = [filterNameSet is_local (tyClsNamesOfType ty) | ty <- tys]
1264 orph | is_local cls_name = Just (nameOccName cls_name)
1265 | all isJust mb_ns = head mb_ns
1266 | otherwise = Nothing
1268 mb_ns :: [Maybe OccName] -- One for each fundep; a locally-defined name
1269 -- that is not in the "determined" arguments
1270 mb_ns | null fds = [choose_one arg_names]
1271 | otherwise = map do_one fds
1272 do_one (ltvs,rtvs) = choose_one [ns | (tv,ns) <- tvs `zip` arg_names
1273 , not (tv `elem` rtvs)]
1275 choose_one :: [NameSet] -> Maybe OccName
1276 choose_one nss = case nameSetToList (unionManyNameSets nss) of
1278 (n:ns) -> Just (nameOccName n)
1280 --------------------------
1281 famInstToIfaceFamInst :: FamInst -> IfaceFamInst
1282 famInstToIfaceFamInst fi@(FamInst { fi_tycon = tycon,
1283 fi_fam = fam, fi_tcs = mb_tcs })
1284 = IfaceFamInst { ifFamInstTyCon = toIfaceTyCon tycon
1285 , ifFamInstFam = fam
1286 , ifFamInstTys = map do_rough mb_tcs }
1288 do_rough Nothing = Nothing
1289 do_rough (Just n) = Just (toIfaceTyCon_name n)
1291 --------------------------
1292 toIfaceLetBndr id = IfLetBndr (occNameFS (getOccName id))
1293 (toIfaceType (idType id))
1296 -- Stripped-down version of tcIfaceIdInfo
1297 -- Change this if you want to export more IdInfo for
1298 -- non-top-level Ids. Don't forget to change
1299 -- CoreTidy.tidyLetBndr too!
1301 -- See Note [IdInfo on nested let-bindings] in IfaceSyn
1303 inline_prag = inlinePragInfo id_info
1304 prag_info | isAlwaysActive inline_prag = NoInfo
1305 | otherwise = HasInfo [HsInline inline_prag]
1307 --------------------------
1308 toIfaceIdInfo :: IdInfo -> [IfaceInfoItem]
1309 toIfaceIdInfo id_info
1310 = catMaybes [arity_hsinfo, caf_hsinfo, strict_hsinfo,
1311 inline_hsinfo, wrkr_hsinfo, unfold_hsinfo]
1313 ------------ Arity --------------
1314 arity_info = arityInfo id_info
1315 arity_hsinfo | arity_info == 0 = Nothing
1316 | otherwise = Just (HsArity arity_info)
1318 ------------ Caf Info --------------
1319 caf_info = cafInfo id_info
1320 caf_hsinfo = case caf_info of
1321 NoCafRefs -> Just HsNoCafRefs
1324 ------------ Strictness --------------
1325 -- No point in explicitly exporting TopSig
1326 strict_hsinfo = case newStrictnessInfo id_info of
1327 Just sig | not (isTopSig sig) -> Just (HsStrictness sig)
1330 ------------ Worker --------------
1331 work_info = workerInfo id_info
1332 has_worker = workerExists work_info
1333 wrkr_hsinfo = case work_info of
1334 HasWorker work_id wrap_arity ->
1335 Just (HsWorker ((idName work_id)) wrap_arity)
1338 ------------ Unfolding --------------
1339 -- The unfolding is redundant if there is a worker
1340 unfold_info = unfoldingInfo id_info
1341 rhs = unfoldingTemplate unfold_info
1342 no_unfolding = neverUnfold unfold_info
1343 -- The CoreTidy phase retains unfolding info iff
1344 -- we want to expose the unfolding, taking into account
1345 -- unconditional NOINLINE, etc. See TidyPgm.addExternal
1346 unfold_hsinfo | no_unfolding = Nothing
1347 | has_worker = Nothing -- Unfolding is implicit
1348 | otherwise = Just (HsUnfold (toIfaceExpr rhs))
1350 ------------ Inline prag --------------
1351 inline_prag = inlinePragInfo id_info
1352 inline_hsinfo | isAlwaysActive inline_prag = Nothing
1353 | no_unfolding && not has_worker = Nothing
1354 -- If the iface file give no unfolding info, we
1355 -- don't need to say when inlining is OK!
1356 | otherwise = Just (HsInline inline_prag)
1358 --------------------------
1359 coreRuleToIfaceRule :: Module -> CoreRule -> IfaceRule
1360 coreRuleToIfaceRule mod (BuiltinRule { ru_fn = fn})
1361 = pprTrace "toHsRule: builtin" (ppr fn) $
1364 coreRuleToIfaceRule mod (Rule { ru_name = name, ru_fn = fn,
1365 ru_act = act, ru_bndrs = bndrs,
1366 ru_args = args, ru_rhs = rhs })
1367 = IfaceRule { ifRuleName = name, ifActivation = act,
1368 ifRuleBndrs = map toIfaceBndr bndrs,
1370 ifRuleArgs = map do_arg args,
1371 ifRuleRhs = toIfaceExpr rhs,
1374 -- For type args we must remove synonyms from the outermost
1375 -- level. Reason: so that when we read it back in we'll
1376 -- construct the same ru_rough field as we have right now;
1378 do_arg (Type ty) = IfaceType (toIfaceType (deNoteType ty))
1379 do_arg arg = toIfaceExpr arg
1381 -- Compute orphanhood. See Note [Orphans] in IfaceSyn
1382 -- A rule is an orphan only if none of the variables
1383 -- mentioned on its left-hand side are locally defined
1384 lhs_names = fn : nameSetToList (exprsFreeNames args)
1385 -- No need to delete bndrs, because
1386 -- exprsFreeNames finds only External names
1388 orph = case filter (nameIsLocalOrFrom mod) lhs_names of
1389 (n:ns) -> Just (nameOccName n)
1392 bogusIfaceRule :: Name -> IfaceRule
1393 bogusIfaceRule id_name
1394 = IfaceRule { ifRuleName = FSLIT("bogus"), ifActivation = NeverActive,
1395 ifRuleBndrs = [], ifRuleHead = id_name, ifRuleArgs = [],
1396 ifRuleRhs = IfaceExt id_name, ifRuleOrph = Nothing }
1398 ---------------------
1399 toIfaceExpr :: CoreExpr -> IfaceExpr
1400 toIfaceExpr (Var v) = toIfaceVar v
1401 toIfaceExpr (Lit l) = IfaceLit l
1402 toIfaceExpr (Type ty) = IfaceType (toIfaceType ty)
1403 toIfaceExpr (Lam x b) = IfaceLam (toIfaceBndr x) (toIfaceExpr b)
1404 toIfaceExpr (App f a) = toIfaceApp f [a]
1405 toIfaceExpr (Case s x ty as) = IfaceCase (toIfaceExpr s) (getFS x) (toIfaceType ty) (map toIfaceAlt as)
1406 toIfaceExpr (Let b e) = IfaceLet (toIfaceBind b) (toIfaceExpr e)
1407 toIfaceExpr (Cast e co) = IfaceCast (toIfaceExpr e) (toIfaceType co)
1408 toIfaceExpr (Note n e) = IfaceNote (toIfaceNote n) (toIfaceExpr e)
1410 ---------------------
1411 toIfaceNote (SCC cc) = IfaceSCC cc
1412 toIfaceNote InlineMe = IfaceInlineMe
1413 toIfaceNote (CoreNote s) = IfaceCoreNote s
1415 ---------------------
1416 toIfaceBind (NonRec b r) = IfaceNonRec (toIfaceLetBndr b) (toIfaceExpr r)
1417 toIfaceBind (Rec prs) = IfaceRec [(toIfaceLetBndr b, toIfaceExpr r) | (b,r) <- prs]
1419 ---------------------
1420 toIfaceAlt (c,bs,r) = (toIfaceCon c, map getFS bs, toIfaceExpr r)
1422 ---------------------
1423 toIfaceCon (DataAlt dc) | isTupleTyCon tc = IfaceTupleAlt (tupleTyConBoxity tc)
1424 | otherwise = IfaceDataAlt (getName dc)
1426 tc = dataConTyCon dc
1428 toIfaceCon (LitAlt l) = IfaceLitAlt l
1429 toIfaceCon DEFAULT = IfaceDefault
1431 ---------------------
1432 toIfaceApp (App f a) as = toIfaceApp f (a:as)
1433 toIfaceApp (Var v) as
1434 = case isDataConWorkId_maybe v of
1435 -- We convert the *worker* for tuples into IfaceTuples
1436 Just dc | isTupleTyCon tc && saturated
1437 -> IfaceTuple (tupleTyConBoxity tc) tup_args
1439 val_args = dropWhile isTypeArg as
1440 saturated = val_args `lengthIs` idArity v
1441 tup_args = map toIfaceExpr val_args
1442 tc = dataConTyCon dc
1444 other -> mkIfaceApps (toIfaceVar v) as
1446 toIfaceApp e as = mkIfaceApps (toIfaceExpr e) as
1448 mkIfaceApps f as = foldl (\f a -> IfaceApp f (toIfaceExpr a)) f as
1450 ---------------------
1451 toIfaceVar :: Id -> IfaceExpr
1453 | Just fcall <- isFCallId_maybe v = IfaceFCall fcall (toIfaceType (idType v))
1454 -- Foreign calls have special syntax
1455 | isExternalName name = IfaceExt name
1456 | Just (TickBox m ix) <- isTickBoxOp_maybe v
1458 | otherwise = IfaceLcl (getFS name)