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 = mkIfaceDeprec 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 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
695 mkIfaceDeprec NoDeprecs = NoDeprecs
696 mkIfaceDeprec (DeprecAll t) = DeprecAll t
697 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
699 ----------------------
700 bump_unless :: Bool -> Version -> Version
701 bump_unless True v = v -- True <=> no change
702 bump_unless False v = bumpVersion v
706 %*********************************************************
708 \subsection{Keeping track of what we've slurped, and version numbers}
710 %*********************************************************
714 mkUsageInfo :: HscEnv
715 -> ModuleEnv (Module, [(ModuleName, Bool, SrcSpan)])
716 -> [(ModuleName, IsBootInterface)]
717 -> NameSet -> IO [Usage]
718 mkUsageInfo hsc_env dir_imp_mods dep_mods used_names
719 = do { eps <- hscEPS hsc_env
720 ; let usages = mk_usage_info (eps_PIT eps) hsc_env
721 dir_imp_mods dep_mods used_names
722 ; usages `seqList` return usages }
723 -- seq the list of Usages returned: occasionally these
724 -- don't get evaluated for a while and we can end up hanging on to
725 -- the entire collection of Ifaces.
727 mk_usage_info :: PackageIfaceTable
729 -> ModuleEnv (Module, [(ModuleName, Bool, SrcSpan)])
730 -> [(ModuleName, IsBootInterface)]
733 mk_usage_info pit hsc_env dir_imp_mods dep_mods used_names
734 = mapCatMaybes mkUsage dep_mods
735 -- ToDo: do we need to sort into canonical order?
737 hpt = hsc_HPT hsc_env
738 dflags = hsc_dflags hsc_env
740 -- ent_map groups together all the things imported and used
741 -- from a particular module in this package
742 ent_map :: ModuleEnv [OccName]
743 ent_map = foldNameSet add_mv emptyModuleEnv used_names
745 | isWiredInName name = mv_map -- ignore wired-in names
747 = case nameModule_maybe name of
748 Nothing -> mv_map -- ignore internal names
749 Just mod -> extendModuleEnv_C add_item mv_map mod [occ]
751 occ = nameOccName name
752 add_item occs _ = occ:occs
754 depend_on_exports mod = case lookupModuleEnv dir_imp_mods mod of
755 Just (_, xs) -> any (\(_, no_imp, _) -> not no_imp) xs
758 -- We want to create a Usage for a home module if
759 -- a) we used something from; has something in used_names
760 -- b) we imported all of it, even if we used nothing from it
761 -- (need to recompile if its export list changes: export_vers)
762 -- c) is a home-package orphan or family-instance module (need to
763 -- recompile if its instance decls change: rules_vers)
764 mkUsage :: (ModuleName, IsBootInterface) -> Maybe Usage
765 mkUsage (mod_name, _)
766 | isNothing maybe_iface -- We can't depend on it if we didn't
767 || (null used_occs -- load its interface.
768 && isNothing export_vers
771 = Nothing -- Record no usage info
774 = Just (Usage { usg_name = mod_name,
776 usg_exports = export_vers,
777 usg_entities = fmToList ent_vers,
778 usg_rules = rules_vers })
780 maybe_iface = lookupIfaceByModule dflags hpt pit mod
781 -- In one-shot mode, the interfaces for home-package
782 -- modules accumulate in the PIT not HPT. Sigh.
784 mod = mkModule (thisPackage dflags) mod_name
786 Just iface = maybe_iface
787 orphan_mod = mi_orphan iface
788 finsts_mod = mi_finsts iface
789 version_env = mi_ver_fn iface
790 mod_vers = mi_mod_vers iface
791 rules_vers = mi_rule_vers iface
792 export_vers | depend_on_exports mod = Just (mi_exp_vers iface)
793 | otherwise = Nothing
795 used_occs = lookupModuleEnv ent_map mod `orElse` []
797 -- Making a FiniteMap here ensures that (a) we remove duplicates
798 -- when we have usages on several subordinates of a single parent,
799 -- and (b) that the usages emerge in a canonical order, which
800 -- is why we use FiniteMap rather than OccEnv: FiniteMap works
801 -- using Ord on the OccNames, which is a lexicographic ordering.
802 ent_vers :: FiniteMap OccName Version
803 ent_vers = listToFM (map lookup_occ used_occs)
806 case version_env occ of
807 Nothing -> pprTrace "hmm, strange" (ppr mod <+> ppr occ) $
808 (occ, initialVersion) -- does this ever happen?
809 Just (parent, version) -> (parent, version)
813 mkIfaceExports :: [AvailInfo]
814 -> [(Module, [GenAvailInfo OccName])]
815 -- Group by module and sort by occurrence
816 -- This keeps the list in canonical order
817 mkIfaceExports exports
818 = [ (mod, eltsFM avails)
819 | (mod, avails) <- fmToList groupFM
822 -- Group by the module where the exported entities are defined
823 -- (which may not be the same for all Names in an Avail)
824 -- Deliberately use FiniteMap rather than UniqFM so we
825 -- get a canonical ordering
826 groupFM :: ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
827 groupFM = foldl add emptyModuleEnv exports
829 add_one :: ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
830 -> Module -> GenAvailInfo OccName
831 -> ModuleEnv (FiniteMap FastString (GenAvailInfo OccName))
832 add_one env mod avail
833 = extendModuleEnv_C plusFM env mod
834 (unitFM (occNameFS (availName avail)) avail)
836 -- NB: we should not get T(X) and T(Y) in the export list
837 -- else the plusFM will simply discard one! They
838 -- should have been combined by now.
840 = add_one env (nameModule n) (Avail (nameOccName n))
842 add env (AvailTC tc ns)
843 = foldl add_for_mod env mods
845 tc_occ = nameOccName tc
846 mods = nub (map nameModule ns)
847 -- Usually just one, but see Note [Original module]
850 = add_one env mod (AvailTC tc_occ (sort names_from_mod))
851 -- NB. sort the children, we need a canonical order
853 names_from_mod = [nameOccName n | n <- ns, nameModule n == mod]
856 Note [Orignal module]
857 ~~~~~~~~~~~~~~~~~~~~~
859 module X where { data family T }
860 module Y( T(..) ) where { import X; data instance T Int = MkT Int }
861 The exported Avail from Y will look like
864 - only MkT is brought into scope by the data instance;
865 - but the parent (used for grouping and naming in T(..) exports) is X.T
866 - and in this case we export X.T too
868 In the result of MkIfaceExports, the names are grouped by defining module,
869 so we may need to split up a single Avail into multiple ones.
872 %************************************************************************
874 Load the old interface file for this module (unless
875 we have it aleady), and check whether it is up to date
878 %************************************************************************
881 checkOldIface :: HscEnv
883 -> Bool -- Source unchanged
884 -> Maybe ModIface -- Old interface from compilation manager, if any
885 -> IO (RecompileRequired, Maybe ModIface)
887 checkOldIface hsc_env mod_summary source_unchanged maybe_iface
888 = do { showPass (hsc_dflags hsc_env)
889 ("Checking old interface for " ++
890 showSDoc (ppr (ms_mod mod_summary))) ;
892 ; initIfaceCheck hsc_env $
893 check_old_iface hsc_env mod_summary source_unchanged maybe_iface
896 check_old_iface hsc_env mod_summary source_unchanged maybe_iface
897 = do -- CHECK WHETHER THE SOURCE HAS CHANGED
898 { ifM (not source_unchanged)
899 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
901 -- If the source has changed and we're in interactive mode, avoid reading
902 -- an interface; just return the one we might have been supplied with.
903 ; let dflags = hsc_dflags hsc_env
904 ; if not (isObjectTarget (hscTarget dflags)) && not source_unchanged then
905 return (outOfDate, maybe_iface)
907 case maybe_iface of {
908 Just old_iface -> do -- Use the one we already have
909 { traceIf (text "We already have the old interface for" <+> ppr (ms_mod mod_summary))
910 ; recomp <- checkVersions hsc_env source_unchanged mod_summary old_iface
911 ; return (recomp, Just old_iface) }
915 -- Try and read the old interface for the current module
916 -- from the .hi file left from the last time we compiled it
917 { let iface_path = msHiFilePath mod_summary
918 ; read_result <- readIface (ms_mod mod_summary) iface_path False
919 ; case read_result of {
920 Failed err -> do -- Old interface file not found, or garbled; give up
921 { traceIf (text "FYI: cannot read old interface file:"
923 ; return (outOfDate, Nothing) }
925 ; Succeeded iface -> do
927 -- We have got the old iface; check its versions
928 { traceIf (text "Read the interface file" <+> text iface_path)
929 ; recomp <- checkVersions hsc_env source_unchanged mod_summary iface
930 ; returnM (recomp, Just iface)
935 @recompileRequired@ is called from the HscMain. It checks whether
936 a recompilation is required. It needs access to the persistent state,
937 finder, etc, because it may have to load lots of interface files to
938 check their versions.
941 type RecompileRequired = Bool
942 upToDate = False -- Recompile not required
943 outOfDate = True -- Recompile required
945 checkVersions :: HscEnv
946 -> Bool -- True <=> source unchanged
948 -> ModIface -- Old interface
949 -> IfG RecompileRequired
950 checkVersions hsc_env source_unchanged mod_summary iface
951 | not source_unchanged
954 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
955 ppr (mi_module iface) <> colon)
957 ; recomp <- checkDependencies hsc_env mod_summary iface
958 ; if recomp then return outOfDate else do {
960 -- Source code unchanged and no errors yet... carry on
962 -- First put the dependent-module info, read from the old interface, into the envt,
963 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
965 -- It's just temporary because either the usage check will succeed
966 -- (in which case we are done with this module) or it'll fail (in which
967 -- case we'll compile the module from scratch anyhow).
969 -- We do this regardless of compilation mode, although in --make mode
970 -- all the dependent modules should be in the HPT already, so it's
972 updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
974 ; let this_pkg = thisPackage (hsc_dflags hsc_env)
975 ; checkList [checkModUsage this_pkg u | u <- mi_usages iface]
978 -- This is a bit of a hack really
979 mod_deps :: ModuleNameEnv (ModuleName, IsBootInterface)
980 mod_deps = mkModDeps (dep_mods (mi_deps iface))
983 -- If the direct imports of this module are resolved to targets that
984 -- are not among the dependencies of the previous interface file,
985 -- then we definitely need to recompile. This catches cases like
986 -- - an exposed package has been upgraded
987 -- - we are compiling with different package flags
988 -- - a home module that was shadowing a package module has been removed
989 -- - a new home module has been added that shadows a package module
992 -- Returns True if recompilation is required.
993 checkDependencies :: HscEnv -> ModSummary -> ModIface -> IfG RecompileRequired
994 checkDependencies hsc_env summary iface
995 = orM (map dep_missing (ms_imps summary ++ ms_srcimps summary))
997 prev_dep_mods = dep_mods (mi_deps iface)
998 prev_dep_pkgs = dep_pkgs (mi_deps iface)
1000 this_pkg = thisPackage (hsc_dflags hsc_env)
1002 orM = foldr f (return False)
1003 where f m rest = do b <- m; if b then return True else rest
1005 dep_missing (L _ mod) = do
1006 find_res <- ioToIOEnv $ findImportedModule hsc_env mod Nothing
1010 -> if moduleName mod `notElem` map fst prev_dep_mods
1011 then do traceHiDiffs $
1012 text "imported module " <> quotes (ppr mod) <>
1013 text " not among previous dependencies"
1018 -> if pkg `notElem` prev_dep_pkgs
1019 then do traceHiDiffs $
1020 text "imported module " <> quotes (ppr mod) <>
1021 text " is from package " <> quotes (ppr pkg) <>
1022 text ", which is not among previous dependencies"
1026 where pkg = modulePackageId mod
1027 _otherwise -> return outOfDate
1029 checkModUsage :: PackageId ->Usage -> IfG RecompileRequired
1030 -- Given the usage information extracted from the old
1031 -- M.hi file for the module being compiled, figure out
1032 -- whether M needs to be recompiled.
1034 checkModUsage this_pkg (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
1035 usg_rules = old_rule_vers,
1036 usg_exports = maybe_old_export_vers,
1037 usg_entities = old_decl_vers })
1038 = -- Load the imported interface is possible
1040 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
1042 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
1045 mod = mkModule this_pkg mod_name
1047 loadInterface doc_str mod ImportBySystem `thenM` \ mb_iface ->
1048 -- Load the interface, but don't complain on failure;
1049 -- Instead, get an Either back which we can test
1052 Failed exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
1054 -- Couldn't find or parse a module mentioned in the
1055 -- old interface file. Don't complain -- it might just be that
1056 -- the current module doesn't need that import and it's been deleted
1060 new_mod_vers = mi_mod_vers iface
1061 new_decl_vers = mi_ver_fn iface
1062 new_export_vers = mi_exp_vers iface
1063 new_rule_vers = mi_rule_vers iface
1066 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
1067 if not recompile then
1071 -- CHECK EXPORT LIST
1072 if checkExportList maybe_old_export_vers new_export_vers then
1073 out_of_date_vers (ptext SLIT(" Export list changed"))
1074 (expectJust "checkModUsage" maybe_old_export_vers)
1079 if old_rule_vers /= new_rule_vers then
1080 out_of_date_vers (ptext SLIT(" Rules changed"))
1081 old_rule_vers new_rule_vers
1084 -- CHECK ITEMS ONE BY ONE
1085 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
1087 returnM outOfDate -- This one failed, so just bail out now
1089 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
1092 ------------------------
1093 checkModuleVersion old_mod_vers new_mod_vers
1094 | new_mod_vers == old_mod_vers
1095 = up_to_date (ptext SLIT("Module version unchanged"))
1098 = out_of_date_vers (ptext SLIT(" Module version has changed"))
1099 old_mod_vers new_mod_vers
1101 ------------------------
1102 checkExportList Nothing new_vers = upToDate
1103 checkExportList (Just v) new_vers = v /= new_vers
1105 ------------------------
1106 checkEntityUsage new_vers (name,old_vers)
1107 = case new_vers name of
1109 Nothing -> -- We used it before, but it ain't there now
1110 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
1112 Just (_, new_vers) -- It's there, but is it up to date?
1113 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
1115 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
1118 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
1119 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
1120 out_of_date_vers msg old_vers new_vers
1121 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
1123 ----------------------
1124 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
1125 -- This helper is used in two places
1126 checkList [] = returnM upToDate
1127 checkList (check:checks) = check `thenM` \ recompile ->
1134 %************************************************************************
1136 Converting things to their Iface equivalents
1138 %************************************************************************
1141 tyThingToIfaceDecl :: TyThing -> IfaceDecl
1142 -- Assumption: the thing is already tidied, so that locally-bound names
1143 -- (lambdas, for-alls) already have non-clashing OccNames
1144 -- Reason: Iface stuff uses OccNames, and the conversion here does
1145 -- not do tidying on the way
1146 tyThingToIfaceDecl (AnId id)
1147 = IfaceId { ifName = getOccName id,
1148 ifType = toIfaceType (idType id),
1151 info = case toIfaceIdInfo (idInfo id) of
1153 items -> HasInfo items
1155 tyThingToIfaceDecl (AClass clas)
1156 = IfaceClass { ifCtxt = toIfaceContext sc_theta,
1157 ifName = getOccName clas,
1158 ifTyVars = toIfaceTvBndrs clas_tyvars,
1159 ifFDs = map toIfaceFD clas_fds,
1160 ifATs = map (tyThingToIfaceDecl . ATyCon) clas_ats,
1161 ifSigs = map toIfaceClassOp op_stuff,
1162 ifRec = boolToRecFlag (isRecursiveTyCon tycon) }
1164 (clas_tyvars, clas_fds, sc_theta, _, clas_ats, op_stuff)
1165 = classExtraBigSig clas
1166 tycon = classTyCon clas
1168 toIfaceClassOp (sel_id, def_meth)
1169 = ASSERT(sel_tyvars == clas_tyvars)
1170 IfaceClassOp (getOccName sel_id) def_meth (toIfaceType op_ty)
1172 -- Be careful when splitting the type, because of things
1173 -- like class Foo a where
1174 -- op :: (?x :: String) => a -> a
1175 -- and class Baz a where
1176 -- op :: (Ord a) => a -> a
1177 (sel_tyvars, rho_ty) = splitForAllTys (idType sel_id)
1178 op_ty = funResultTy rho_ty
1180 toIfaceFD (tvs1, tvs2) = (map getFS tvs1, map getFS tvs2)
1182 tyThingToIfaceDecl (ATyCon tycon)
1184 = IfaceSyn { ifName = getOccName tycon,
1185 ifTyVars = toIfaceTvBndrs tyvars,
1186 ifOpenSyn = syn_isOpen,
1187 ifSynRhs = toIfaceType syn_tyki,
1188 ifFamInst = famInstToIface (tyConFamInst_maybe tycon)
1192 = IfaceData { ifName = getOccName tycon,
1193 ifTyVars = toIfaceTvBndrs tyvars,
1194 ifCtxt = toIfaceContext (tyConStupidTheta tycon),
1195 ifCons = ifaceConDecls (algTyConRhs tycon),
1196 ifRec = boolToRecFlag (isRecursiveTyCon tycon),
1197 ifGadtSyntax = isGadtSyntaxTyCon tycon,
1198 ifGeneric = tyConHasGenerics tycon,
1199 ifFamInst = famInstToIface (tyConFamInst_maybe tycon)}
1201 | isForeignTyCon tycon
1202 = IfaceForeign { ifName = getOccName tycon,
1203 ifExtName = tyConExtName tycon }
1205 | otherwise = pprPanic "toIfaceDecl" (ppr tycon)
1207 tyvars = tyConTyVars tycon
1208 (syn_isOpen, syn_tyki) = case synTyConRhs tycon of
1209 OpenSynTyCon ki _ -> (True , ki)
1210 SynonymTyCon ty -> (False, ty)
1212 ifaceConDecls (NewTyCon { data_con = con }) =
1213 IfNewTyCon (ifaceConDecl con)
1214 ifaceConDecls (DataTyCon { data_cons = cons }) =
1215 IfDataTyCon (map ifaceConDecl cons)
1216 ifaceConDecls OpenTyCon {} = IfOpenDataTyCon
1217 ifaceConDecls AbstractTyCon = IfAbstractTyCon
1218 -- The last case happens when a TyCon has been trimmed during tidying
1219 -- Furthermore, tyThingToIfaceDecl is also used
1220 -- in TcRnDriver for GHCi, when browsing a module, in which case the
1221 -- AbstractTyCon case is perfectly sensible.
1223 ifaceConDecl data_con
1224 = IfCon { ifConOcc = getOccName (dataConName data_con),
1225 ifConInfix = dataConIsInfix data_con,
1226 ifConUnivTvs = toIfaceTvBndrs (dataConUnivTyVars data_con),
1227 ifConExTvs = toIfaceTvBndrs (dataConExTyVars data_con),
1228 ifConEqSpec = to_eq_spec (dataConEqSpec data_con),
1229 ifConCtxt = toIfaceContext (dataConEqTheta data_con ++ dataConDictTheta data_con),
1230 ifConArgTys = map toIfaceType (dataConOrigArgTys data_con),
1231 ifConFields = map getOccName
1232 (dataConFieldLabels data_con),
1233 ifConStricts = dataConStrictMarks data_con }
1235 to_eq_spec spec = [(getOccName tv, toIfaceType ty) | (tv,ty) <- spec]
1237 famInstToIface Nothing = Nothing
1238 famInstToIface (Just (famTyCon, instTys)) =
1239 Just (toIfaceTyCon famTyCon, map toIfaceType instTys)
1241 tyThingToIfaceDecl (ADataCon dc)
1242 = pprPanic "toIfaceDecl" (ppr dc) -- Should be trimmed out earlier
1245 getFS x = occNameFS (getOccName x)
1247 --------------------------
1248 instanceToIfaceInst :: Instance -> IfaceInst
1249 instanceToIfaceInst ispec@(Instance { is_dfun = dfun_id, is_flag = oflag,
1250 is_cls = cls_name, is_tcs = mb_tcs })
1251 = ASSERT( cls_name == className cls )
1252 IfaceInst { ifDFun = dfun_name,
1254 ifInstCls = cls_name,
1255 ifInstTys = map do_rough mb_tcs,
1258 do_rough Nothing = Nothing
1259 do_rough (Just n) = Just (toIfaceTyCon_name n)
1261 dfun_name = idName dfun_id
1262 mod = nameModule dfun_name
1263 is_local name = nameIsLocalOrFrom mod name
1265 -- Compute orphanhood. See Note [Orphans] in IfaceSyn
1266 (_, _, cls, tys) = tcSplitDFunTy (idType dfun_id)
1267 -- Slightly awkward: we need the Class to get the fundeps
1268 (tvs, fds) = classTvsFds cls
1269 arg_names = [filterNameSet is_local (tyClsNamesOfType ty) | ty <- tys]
1270 orph | is_local cls_name = Just (nameOccName cls_name)
1271 | all isJust mb_ns = head mb_ns
1272 | otherwise = Nothing
1274 mb_ns :: [Maybe OccName] -- One for each fundep; a locally-defined name
1275 -- that is not in the "determined" arguments
1276 mb_ns | null fds = [choose_one arg_names]
1277 | otherwise = map do_one fds
1278 do_one (ltvs,rtvs) = choose_one [ns | (tv,ns) <- tvs `zip` arg_names
1279 , not (tv `elem` rtvs)]
1281 choose_one :: [NameSet] -> Maybe OccName
1282 choose_one nss = case nameSetToList (unionManyNameSets nss) of
1284 (n:ns) -> Just (nameOccName n)
1286 --------------------------
1287 famInstToIfaceFamInst :: FamInst -> IfaceFamInst
1288 famInstToIfaceFamInst fi@(FamInst { fi_tycon = tycon,
1289 fi_fam = fam, fi_tcs = mb_tcs })
1290 = IfaceFamInst { ifFamInstTyCon = toIfaceTyCon tycon
1291 , ifFamInstFam = fam
1292 , ifFamInstTys = map do_rough mb_tcs }
1294 do_rough Nothing = Nothing
1295 do_rough (Just n) = Just (toIfaceTyCon_name n)
1297 --------------------------
1298 toIfaceLetBndr id = IfLetBndr (occNameFS (getOccName id))
1299 (toIfaceType (idType id))
1302 -- Stripped-down version of tcIfaceIdInfo
1303 -- Change this if you want to export more IdInfo for
1304 -- non-top-level Ids. Don't forget to change
1305 -- CoreTidy.tidyLetBndr too!
1307 -- See Note [IdInfo on nested let-bindings] in IfaceSyn
1309 inline_prag = inlinePragInfo id_info
1310 prag_info | isAlwaysActive inline_prag = NoInfo
1311 | otherwise = HasInfo [HsInline inline_prag]
1313 --------------------------
1314 toIfaceIdInfo :: IdInfo -> [IfaceInfoItem]
1315 toIfaceIdInfo id_info
1316 = catMaybes [arity_hsinfo, caf_hsinfo, strict_hsinfo,
1317 inline_hsinfo, wrkr_hsinfo, unfold_hsinfo]
1319 ------------ Arity --------------
1320 arity_info = arityInfo id_info
1321 arity_hsinfo | arity_info == 0 = Nothing
1322 | otherwise = Just (HsArity arity_info)
1324 ------------ Caf Info --------------
1325 caf_info = cafInfo id_info
1326 caf_hsinfo = case caf_info of
1327 NoCafRefs -> Just HsNoCafRefs
1330 ------------ Strictness --------------
1331 -- No point in explicitly exporting TopSig
1332 strict_hsinfo = case newStrictnessInfo id_info of
1333 Just sig | not (isTopSig sig) -> Just (HsStrictness sig)
1336 ------------ Worker --------------
1337 work_info = workerInfo id_info
1338 has_worker = workerExists work_info
1339 wrkr_hsinfo = case work_info of
1340 HasWorker work_id wrap_arity ->
1341 Just (HsWorker ((idName work_id)) wrap_arity)
1344 ------------ Unfolding --------------
1345 -- The unfolding is redundant if there is a worker
1346 unfold_info = unfoldingInfo id_info
1347 rhs = unfoldingTemplate unfold_info
1348 no_unfolding = neverUnfold unfold_info
1349 -- The CoreTidy phase retains unfolding info iff
1350 -- we want to expose the unfolding, taking into account
1351 -- unconditional NOINLINE, etc. See TidyPgm.addExternal
1352 unfold_hsinfo | no_unfolding = Nothing
1353 | has_worker = Nothing -- Unfolding is implicit
1354 | otherwise = Just (HsUnfold (toIfaceExpr rhs))
1356 ------------ Inline prag --------------
1357 inline_prag = inlinePragInfo id_info
1358 inline_hsinfo | isAlwaysActive inline_prag = Nothing
1359 | no_unfolding && not has_worker = Nothing
1360 -- If the iface file give no unfolding info, we
1361 -- don't need to say when inlining is OK!
1362 | otherwise = Just (HsInline inline_prag)
1364 --------------------------
1365 coreRuleToIfaceRule :: Module -> CoreRule -> IfaceRule
1366 coreRuleToIfaceRule mod (BuiltinRule { ru_fn = fn})
1367 = pprTrace "toHsRule: builtin" (ppr fn) $
1370 coreRuleToIfaceRule mod (Rule { ru_name = name, ru_fn = fn,
1371 ru_act = act, ru_bndrs = bndrs,
1372 ru_args = args, ru_rhs = rhs })
1373 = IfaceRule { ifRuleName = name, ifActivation = act,
1374 ifRuleBndrs = map toIfaceBndr bndrs,
1376 ifRuleArgs = map do_arg args,
1377 ifRuleRhs = toIfaceExpr rhs,
1380 -- For type args we must remove synonyms from the outermost
1381 -- level. Reason: so that when we read it back in we'll
1382 -- construct the same ru_rough field as we have right now;
1384 do_arg (Type ty) = IfaceType (toIfaceType (deNoteType ty))
1385 do_arg arg = toIfaceExpr arg
1387 -- Compute orphanhood. See Note [Orphans] in IfaceSyn
1388 -- A rule is an orphan only if none of the variables
1389 -- mentioned on its left-hand side are locally defined
1390 lhs_names = fn : nameSetToList (exprsFreeNames args)
1391 -- No need to delete bndrs, because
1392 -- exprsFreeNames finds only External names
1394 orph = case filter (nameIsLocalOrFrom mod) lhs_names of
1395 (n:ns) -> Just (nameOccName n)
1398 bogusIfaceRule :: Name -> IfaceRule
1399 bogusIfaceRule id_name
1400 = IfaceRule { ifRuleName = FSLIT("bogus"), ifActivation = NeverActive,
1401 ifRuleBndrs = [], ifRuleHead = id_name, ifRuleArgs = [],
1402 ifRuleRhs = IfaceExt id_name, ifRuleOrph = Nothing }
1404 ---------------------
1405 toIfaceExpr :: CoreExpr -> IfaceExpr
1406 toIfaceExpr (Var v) = toIfaceVar v
1407 toIfaceExpr (Lit l) = IfaceLit l
1408 toIfaceExpr (Type ty) = IfaceType (toIfaceType ty)
1409 toIfaceExpr (Lam x b) = IfaceLam (toIfaceBndr x) (toIfaceExpr b)
1410 toIfaceExpr (App f a) = toIfaceApp f [a]
1411 toIfaceExpr (Case s x ty as) = IfaceCase (toIfaceExpr s) (getFS x) (toIfaceType ty) (map toIfaceAlt as)
1412 toIfaceExpr (Let b e) = IfaceLet (toIfaceBind b) (toIfaceExpr e)
1413 toIfaceExpr (Cast e co) = IfaceCast (toIfaceExpr e) (toIfaceType co)
1414 toIfaceExpr (Note n e) = IfaceNote (toIfaceNote n) (toIfaceExpr e)
1416 ---------------------
1417 toIfaceNote (SCC cc) = IfaceSCC cc
1418 toIfaceNote InlineMe = IfaceInlineMe
1419 toIfaceNote (CoreNote s) = IfaceCoreNote s
1421 ---------------------
1422 toIfaceBind (NonRec b r) = IfaceNonRec (toIfaceLetBndr b) (toIfaceExpr r)
1423 toIfaceBind (Rec prs) = IfaceRec [(toIfaceLetBndr b, toIfaceExpr r) | (b,r) <- prs]
1425 ---------------------
1426 toIfaceAlt (c,bs,r) = (toIfaceCon c, map getFS bs, toIfaceExpr r)
1428 ---------------------
1429 toIfaceCon (DataAlt dc) | isTupleTyCon tc = IfaceTupleAlt (tupleTyConBoxity tc)
1430 | otherwise = IfaceDataAlt (getName dc)
1432 tc = dataConTyCon dc
1434 toIfaceCon (LitAlt l) = IfaceLitAlt l
1435 toIfaceCon DEFAULT = IfaceDefault
1437 ---------------------
1438 toIfaceApp (App f a) as = toIfaceApp f (a:as)
1439 toIfaceApp (Var v) as
1440 = case isDataConWorkId_maybe v of
1441 -- We convert the *worker* for tuples into IfaceTuples
1442 Just dc | isTupleTyCon tc && saturated
1443 -> IfaceTuple (tupleTyConBoxity tc) tup_args
1445 val_args = dropWhile isTypeArg as
1446 saturated = val_args `lengthIs` idArity v
1447 tup_args = map toIfaceExpr val_args
1448 tc = dataConTyCon dc
1450 other -> mkIfaceApps (toIfaceVar v) as
1452 toIfaceApp e as = mkIfaceApps (toIfaceExpr e) as
1454 mkIfaceApps f as = foldl (\f a -> IfaceApp f (toIfaceExpr a)) f as
1456 ---------------------
1457 toIfaceVar :: Id -> IfaceExpr
1459 | Just fcall <- isFCallId_maybe v = IfaceFCall fcall (toIfaceType (idType v))
1460 -- Foreign calls have special syntax
1461 | isExternalName name = IfaceExt name
1462 | Just (TickBox m ix) <- isTickBoxOp_maybe v
1464 | otherwise = IfaceLcl (getFS name)