2 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
7 showIface, -- Print the iface in Foo.hi
9 mkUsageInfo, -- Construct the usage info for a module
11 mkIface, -- Build a ModIface from a ModGuts,
12 -- including computing version information
14 checkOldIface -- See if recompilation is required, by
15 -- comparing version information
19 -----------------------------------------------
20 MkIface.lhs deals with versioning
21 -----------------------------------------------
23 Here's the version-related info in an interface file
25 module Foo 8 -- module-version
26 3 -- export-list-version
28 Usages: -- Version info for what this compilation of Foo imported
29 Baz 3 -- Module version
30 [4] -- The export-list version if Foo depended on it
31 (g,2) -- Function and its version
32 (T,1) -- Type and its version
34 <version> f :: Int -> Int {- Unfolding: \x -> Wib.t[2] x -}
35 -- The [2] says that f's unfolding
36 -- mentions verison 2 of Wib.t
38 -----------------------------------------------
40 -----------------------------------------------
43 * In the mi_usages information in an interface, we record the
44 version number of each free variable of the module
46 * In mkIface, we compute the version number of each exported thing A.f
47 by comparing its A.f's info with its new info, and bumping its
48 version number if it differs. If A.f mentions B.g, and B.g's version
49 number has changed, then we count A.f as having changed too.
51 * In checkOldIface we compare the mi_usages for the module with
52 the actual version info for all each thing recorded in mi_usages
57 We count A.f as changing if its fixity changes
61 If a rule changes, we want to recompile any module that might be
62 affected by that rule. For non-orphan rules, this is relatively easy.
63 If module M defines f, and a rule for f, just arrange that the version
64 number for M.f changes if any of the rules for M.f change. Any module
65 that does not depend on M.f can't be affected by the rule-change
68 Orphan rules (ones whose 'head function' is not defined in M) are
69 harder. Here's what we do.
71 * We have a per-module orphan-rule version number which changes if
72 any orphan rule changes. (It's unaffected by non-orphan rules.)
74 * We record usage info for any orphan module 'below' this one,
75 giving the orphan-rule version number. We recompile if this
78 The net effect is that if an orphan rule changes, we recompile every
79 module above it. That's very conservative, but it's devilishly hard
80 to know what it might affect, so we just have to be conservative.
84 In an iface file we have
86 instance Eq a => Eq [a] = dfun29
89 We have a version number for dfun29, covering its unfolding
90 etc. Suppose we are compiling a module M that imports A only
91 indirectly. If typechecking M uses this instance decl, we record the
92 dependency on A.dfun29 as if it were a free variable of the module
93 (via the tcg_inst_usages accumulator). That means that A will appear
94 in M's usage list. If the shape of the instance declaration changes,
95 then so will dfun29's version, triggering a recompilation.
97 Adding an instance declaration, or changing an instance decl that is
98 not currently used, is more tricky. (This really only makes a
99 difference when we have overlapping instance decls, because then the
100 new instance decl might kick in to override the old one.) We handle
101 this in a very similar way that we handle rules above.
103 * For non-orphan instance decls, identify one locally-defined tycon/class
104 mentioned in the decl. Treat the instance decl as part of the defn of that
105 tycon/class, so that if the shape of the instance decl changes, so does the
106 tycon/class; that in turn will force recompilation of anything that uses
109 * For orphan instance decls, act the same way as for orphan rules.
110 Indeed, we use the same global orphan-rule version number.
114 mkUsageInfo figures out what the ``usage information'' for this
115 moudule is; that is, what it must record in its interface file as the
118 We produce a line for every module B below the module, A, currently being
121 to record the fact that A does import B indirectly. This is used to decide
122 to look to look for B.hi rather than B.hi-boot when compiling a module that
123 imports A. This line says that A imports B, but uses nothing in it.
124 So we'll get an early bale-out when compiling A if B's version changes.
126 The usage information records:
129 \item (a) anything reachable from its body code
130 \item (b) any module exported with a @module Foo@
131 \item (c) anything reachable from an exported item
134 Why (b)? Because if @Foo@ changes then this module's export list
135 will change, so we must recompile this module at least as far as
136 making a new interface file --- but in practice that means complete
139 Why (c)? Consider this:
141 module A( f, g ) where | module B( f ) where
142 import B( f ) | f = h 3
146 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
147 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
148 *identical* to what it was before. If anything about @B.f@ changes
149 than anyone who imports @A@ should be recompiled in case they use
150 @B.f@ (they'll get an early exit if they don't). So, if anything
151 about @B.f@ changes we'd better make sure that something in A.hi
152 changes, and the convenient way to do that is to record the version
153 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
154 complete recompiation of A, which is overkill but it's the only way to
155 write a new, slightly different, A.hi.
157 But the example is tricker. Even if @B.f@ doesn't change at all,
158 @B.h@ may do so, and this change may not be reflected in @f@'s version
159 number. But with -O, a module that imports A must be recompiled if
160 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
161 the occurrence of @B.f@ in the export list *just as if* it were in the
162 code of A, and thereby haul in all the stuff reachable from it.
164 *** Conclusion: if A mentions B.f in its export list,
165 behave just as if A mentioned B.f in its source code,
166 and slurp in B.f and all its transitive closure ***
168 [NB: If B was compiled with -O, but A isn't, we should really *still*
169 haul in all the unfoldings for B, in case the module that imports A *is*
170 compiled with -O. I think this is the case.]
174 #include "HsVersions.h"
177 import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..),
178 IfaceRule(..), IfaceInst(..), IfaceExtName(..), IfaceTyCon(..),
179 eqIfDecl, eqIfRule, eqIfInst, IfaceEq(..), (&&&), bool,
181 tyThingToIfaceDecl, dfunToIfaceInst, coreRuleToIfaceRule )
182 import LoadIface ( readIface, loadInterface, ifaceInstGates )
183 import BasicTypes ( Version, initialVersion, bumpVersion )
185 import TcRnTypes ( ImportAvails(..), mkModDeps )
186 import HscTypes ( ModIface(..), TyThing(..),
187 ModGuts(..), ModGuts, IfaceExport,
190 Dependencies(..), FixItem(..),
191 mkIfaceDepCache, mkIfaceFixCache, mkIfaceVerCache,
193 Avails, AvailInfo, GenAvailInfo(..), availName,
194 ExternalPackageState(..),
195 Usage(..), IsBootInterface,
196 Deprecs(..), IfaceDeprecs, Deprecations,
202 import Name ( Name, nameModule, nameOccName, nameParent, isExternalName,
203 nameParent_maybe, isWiredInName, NamedThing(..), nameModuleName )
206 import OccName ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv_C,
207 OccSet, emptyOccSet, elemOccSet, occSetElts,
208 extendOccSet, extendOccSetList,
209 isEmptyOccSet, intersectOccSet, intersectsOccSet,
211 import TyCon ( visibleDataCons, tyConDataCons, isNewTyCon )
212 import Class ( classSelIds )
213 import DataCon ( dataConName )
214 import Module ( Module, ModuleName, moduleNameFS, moduleName, isHomeModule,
215 ModLocation(..), mkSysModuleNameFS, moduleUserString,
216 ModuleEnv, emptyModuleEnv, lookupModuleEnv,
217 extendModuleEnv_C, moduleEnvElts
220 import DriverUtil ( createDirectoryHierarchy, directoryOf )
221 import Util ( sortLt, seqList )
222 import Binary ( getBinFileWithDict )
223 import BinIface ( writeBinIface, v_IgnoreHiWay )
224 import Unique ( Unique, Uniquable(..) )
225 import ErrUtils ( dumpIfSet_dyn, showPass )
226 import Digraph ( stronglyConnComp, SCC(..) )
230 import DATA_IOREF ( writeIORef )
231 import Monad ( when )
232 import List ( insert )
233 import Maybes ( orElse, mapCatMaybes, isNothing, fromJust, expectJust )
238 %************************************************************************
240 \subsection{Completing an interface}
242 %************************************************************************
247 -> Maybe ModIface -- The old interface, if we have it
248 -> ModGuts -- The compiled, tidied module
249 -> IO ModIface -- The new one, complete with decls and versions
251 -- a) completes the interface
252 -- b) writes it out to a file if necessary
254 mkIface hsc_env location maybe_old_iface
255 guts@ModGuts{ mg_module = this_mod,
258 mg_exports = exports,
259 mg_fix_env = fix_env,
260 mg_deprecs = src_deprecs,
263 mg_types = type_env }
264 = do { eps <- hscEPS hsc_env
265 ; let { this_mod_name = moduleName this_mod
266 ; ext_nm = mkExtNameFn hsc_env eps this_mod_name
267 ; local_things = [thing | thing <- typeEnvElts type_env,
268 not (isWiredInName (getName thing)) ]
269 -- Do not export anything about wired-in things
270 -- (GHC knows about them already)
272 ; abstract_tcs :: NameSet -- TyCons and Classes whose representation is not exposed
274 | not omit_prags = emptyNameSet -- In the -O case, nothing is abstract
275 | otherwise = mkNameSet [ getName thing
276 | thing <- local_things
277 , isAbstractThing exports thing]
279 ; decls = [ tyThingToIfaceDecl omit_prags abstract_tcs ext_nm thing
280 | thing <- local_things, wantDeclFor exports abstract_tcs thing ]
281 -- Don't put implicit Ids and class tycons in the interface file
283 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
284 ; deprecs = mkIfaceDeprec src_deprecs
287 | otherwise = sortLt lt_rule $
288 map (coreRuleToIfaceRule this_mod_name ext_nm) rules
289 ; iface_insts = sortLt lt_inst (map (dfunToIfaceInst this_mod_name) insts)
291 ; intermediate_iface = ModIface {
292 mi_module = this_mod,
293 mi_package = opt_InPackage,
297 mi_exports = mkIfaceExports exports,
298 mi_insts = iface_insts,
299 mi_rules = iface_rules,
300 mi_fixities = fixities,
301 mi_deprecs = deprecs,
303 -- Left out deliberately: filled in by addVersionInfo
304 mi_mod_vers = initialVersion,
305 mi_exp_vers = initialVersion,
306 mi_rule_vers = initialVersion,
307 mi_orphan = False, -- Always set by addVersionInfo, but
308 -- it's a strict field, so we can't omit it.
309 mi_decls = deliberatelyOmitted "decls",
310 mi_ver_fn = deliberatelyOmitted "ver_fn",
312 -- And build the cached values
313 mi_dep_fn = mkIfaceDepCache deprecs,
314 mi_fix_fn = mkIfaceFixCache fixities }
316 -- Add version information
317 ; (new_iface, no_change_at_all, pp_diffs)
318 = _scc_ "versioninfo"
319 addVersionInfo maybe_old_iface intermediate_iface decls
322 -- Write the interface file, if necessary
323 ; when (not no_change_at_all && ghci_mode /= Interactive) $ do
324 createDirectoryHierarchy (directoryOf hi_file_path)
325 writeBinIface hi_file_path new_iface
328 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
329 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
330 (pprModIface new_iface)
334 r1 `lt_rule` r2 = ifRuleName r1 < ifRuleName r2
335 i1 `lt_inst` i2 = ifDFun i1 < ifDFun i2
337 dflags = hsc_dflags hsc_env
338 ghci_mode = hsc_mode hsc_env
339 hi_file_path = ml_hi_file location
340 omit_prags = dopt Opt_OmitInterfacePragmas dflags
343 isAbstractThing :: NameSet -> TyThing -> Bool
344 isAbstractThing exports (ATyCon tc)
345 = not (isNewTyCon tc)
346 -- Always expose the rep for newtypes. This is for a
347 -- very annoying reason. 'Foreign import' is meant to
348 -- be able to look through newtypes transparently, but it
349 -- can only do that if it can "see" the newtype representation
350 -- So, for now anyway, we always expose the rep of newtypes. Sigh.
351 && not (any exported_data_con (tyConDataCons tc))
352 -- Don't expose rep if no datacons are exported
354 exported_data_con con = dataConName con `elemNameSet` exports
356 isAbstractThing exports (AClass cls) = not (any exported_class_op (classSelIds cls))
357 where -- Don't expose rep if no classs op is exported
358 exported_class_op op = getName op `elemNameSet` exports
360 isAbstractThing exports other = False
362 wantDeclFor :: NameSet -- User-exported things
363 -> NameSet -- Abstract things
365 wantDeclFor exports abstracts thing
366 | Just parent <- nameParent_maybe name -- An implicit thing
367 = parent `elemNameSet` abstracts && name `elemNameSet` exports
374 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
376 -----------------------------
377 mkExtNameFn :: HscEnv -> ExternalPackageState -> ModuleName -> Name -> IfaceExtName
378 mkExtNameFn hsc_env eps this_mod
381 hpt = hsc_HPT hsc_env
385 | mod_nm == this_mod = case nameParent_maybe name of
386 Nothing -> LocalTop occ
387 Just par -> LocalTopSub occ (nameOccName par)
388 | isWiredInName name = ExtPkg mod_nm occ
389 | isHomeModule mod = HomePkg mod_nm occ vers
390 | otherwise = ExtPkg mod_nm occ
392 mod = nameModule name
393 mod_nm = moduleName mod
394 occ = nameOccName name
395 par_occ = nameOccName (nameParent name)
396 -- The version of the *parent* is the one want
397 vers = lookupVersion mod_nm par_occ
399 lookupVersion :: ModuleName -> OccName -> Version
400 -- Even though we're looking up a home-package thing, in
401 -- one-shot mode the imported interfaces may be in the PIT
402 lookupVersion mod occ
403 = mi_ver_fn iface occ `orElse`
404 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
406 iface = lookupIfaceByModName hpt pit mod `orElse`
407 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
409 -----------------------------
410 -- Compute version numbers for local decls
412 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
413 -> ModIface -- The new interface decls (lacking decls)
414 -> [IfaceDecl] -- The new decls
416 Bool, -- True <=> no changes at all; no need to write new Iface
419 addVersionInfo Nothing new_iface new_decls
420 -- No old interface, so definitely write a new one!
421 = (new_iface { mi_orphan = anyNothing getInstKey (mi_insts new_iface)
422 || anyNothing getRuleKey (mi_rules new_iface),
423 mi_decls = [(initialVersion, decl) | decl <- new_decls],
424 mi_ver_fn = \n -> Just initialVersion },
425 False, ptext SLIT("No old interface file") $$
426 pprOrphans orph_insts orph_rules)
428 orph_insts = filter (isNothing . getInstKey) (mi_insts new_iface)
429 orph_rules = filter (isNothing . getRuleKey) (mi_rules new_iface)
431 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
432 mi_exp_vers = old_exp_vers,
433 mi_rule_vers = old_rule_vers,
434 mi_decls = old_decls,
435 mi_ver_fn = old_decl_vers,
436 mi_fix_fn = old_fixities }))
437 new_iface@(ModIface { mi_fix_fn = new_fixities })
440 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged") $$ pp_orphs)
441 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
443 text "" $$ pp_orphs])
445 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
446 mi_exp_vers = bump_unless no_export_change old_exp_vers,
447 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
448 mi_orphan = not (null new_orph_rules && null new_orph_insts),
449 mi_decls = decls_w_vers,
450 mi_ver_fn = mkIfaceVerCache decls_w_vers }
452 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
455 (old_non_orph_insts, old_orph_insts) = mkRuleMap getInstKey (mi_insts old_iface)
456 (new_non_orph_insts, new_orph_insts) = mkRuleMap getInstKey (mi_insts new_iface)
457 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
458 (lookupOccEnv old_non_orph_insts occ)
459 (lookupOccEnv new_non_orph_insts occ)
461 (old_non_orph_rules, old_orph_rules) = mkRuleMap getRuleKey (mi_rules old_iface)
462 (new_non_orph_rules, new_orph_rules) = mkRuleMap getRuleKey (mi_rules new_iface)
463 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
464 (lookupOccEnv old_non_orph_rules occ)
465 (lookupOccEnv new_non_orph_rules occ)
467 -- Computing what changed
468 no_output_change = no_decl_change && no_rule_change &&
469 no_export_change && no_deprec_change
470 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
471 no_decl_change = isEmptyOccSet changed_occs
472 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
473 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
474 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
476 -- If the usages havn't changed either, we don't need to write the interface file
477 -- Question: should we also check for equality of mi_deps?
478 no_other_changes = mi_usages new_iface == mi_usages old_iface
479 no_change_at_all = no_output_change && no_other_changes
481 pp_diffs = vcat [pp_change no_export_change "Export list"
482 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
483 pp_change no_rule_change "Rules"
484 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
485 pp_change no_deprec_change "Deprecations" empty,
486 pp_change no_other_changes "Usages" empty,
488 pp_change True what info = empty
489 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
492 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
493 same_fixity n = bool (old_fixities n == new_fixities n)
496 -- Adding version info
497 new_version = bumpVersion old_mod_vers
498 add_vers decl | occ `elemOccSet` changed_occs = new_version
499 | otherwise = expectJust "add_vers" (old_decl_vers occ)
500 -- If it's unchanged, there jolly well
501 where -- should be an old version number
505 changed_occs :: OccSet
506 changed_occs = computeChangedOccs eq_info
508 eq_info :: [(OccName, IfaceEq)]
509 eq_info = map check_eq new_decls
510 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
511 = (occ, new_decl `eqIfDecl` old_decl &&&
512 eq_indirects new_decl)
513 | otherwise {- No corresponding old decl -}
516 occ = ifName new_decl
518 eq_indirects :: IfaceDecl -> IfaceEq
519 -- When seeing if two decls are the same, remember to
520 -- check whether any relevant fixity or rules have changed
521 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
522 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
523 = same_insts cls_occ &&&
524 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
525 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
526 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
527 eq_ind_occs [occ | IfaceConDecl occ _ _ _ _ _ <- visibleDataCons cons]
528 eq_indirects other = Equal -- Synonyms and foreign declarations
530 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
531 eq_ind_occ occ = same_fixity occ &&& same_rules occ
532 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
536 pp_decl_diffs :: SDoc -- Nothing => no changes
538 | isEmptyOccSet changed_occs = empty
540 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
541 ptext SLIT("Version change for these decls:"),
542 nest 2 (vcat (map show_change new_decls))]
544 eq_env = mkOccEnv eq_info
546 | not (occ `elemOccSet` changed_occs) = empty
548 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
551 occ = ifName new_decl
552 why = case lookupOccEnv eq_env occ of
553 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
554 nest 2 (braces (fsep (map ppr (occSetElts
555 (occs `intersectOccSet` changed_occs)))))]
557 | Just old_decl <- lookupOccEnv old_decl_env occ
558 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
559 ptext SLIT("New:") <+> ppr new_decl]
561 -> ppr occ <+> ptext SLIT("only in new interface")
562 other -> pprPanic "MkIface.show_change" (ppr occ)
564 pp_orphs = pprOrphans new_orph_insts new_orph_rules
566 pprOrphans insts rules
567 = vcat [if null insts then empty else
568 ptext SLIT("Orphan instances:") <+> vcat (map ppr insts),
569 if null rules then empty else
570 ptext SLIT("Orphan rules:") <+> vcat (map ppr rules)]
572 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
573 computeChangedOccs eq_info
574 = foldl add_changes emptyOccSet (stronglyConnComp edges)
576 edges :: [((OccName,IfaceEq), Unique, [Unique])]
577 edges = [ (node, getUnique occ, map getUnique occs)
578 | node@(occ, iface_eq) <- eq_info
579 , let occs = case iface_eq of
580 EqBut occ_set -> occSetElts occ_set
583 -- Changes in declarations
584 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
585 add_changes so_far (AcyclicSCC (occ, iface_eq))
586 | changedWrt so_far iface_eq -- This one has changed
587 = extendOccSet so_far occ
588 add_changes so_far (CyclicSCC pairs)
589 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
590 = extendOccSetList so_far (map fst pairs)
591 add_changes so_far other = so_far
593 changedWrt :: OccSet -> IfaceEq -> Bool
594 changedWrt so_far Equal = False
595 changedWrt so_far NotEqual = True
596 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
598 ----------------------
599 -- mkRuleMap partitions instance decls or rules into
600 -- (a) an OccEnv for ones that are not orphans,
601 -- mapping the local OccName to a list of its decls
602 -- (b) a list of orphan decls
603 mkRuleMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
604 -- Nothing for an orphan decl
605 -> [decl] -- Sorted into canonical order
606 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
607 -- each sublist in canonical order
608 [decl]) -- Orphan decls; in canonical order
609 mkRuleMap get_key decls
610 = foldl go (emptyOccEnv, []) decls
612 go (non_orphs, orphs) d
613 | Just occ <- get_key d
614 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
615 | otherwise = (non_orphs, d:orphs)
617 -- getXxKey: find at least one local OccName that belongs to this decl
619 getInstKey :: IfaceInst -> Maybe OccName
620 getInstKey (IfaceInst {ifInstHead = inst_ty})
621 = case [occ | LocalTop occ <- cls_ext : tc_exts] of
625 (cls_ext, tcs) = ifaceInstGates inst_ty
626 tc_exts = [tc | IfaceTc tc <- tcs]
627 -- Ignore the wired-in IfaceTyCons; the class will do as the key
629 getRuleKey :: IfaceRule -> Maybe OccName
630 getRuleKey (IfaceRule {ifRuleHead = LocalTop occ}) = Just occ
631 getRuleKey other = Nothing
633 anyNothing :: (a -> Maybe b) -> [a] -> Bool
634 anyNothing p [] = False
635 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
637 ----------------------
638 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
639 mkIfaceDeprec NoDeprecs = NoDeprecs
640 mkIfaceDeprec (DeprecAll t) = DeprecAll t
641 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLt (<) (nameEnvElts env))
643 ----------------------
644 bump_unless :: Bool -> Version -> Version
645 bump_unless True v = v -- True <=> no change
646 bump_unless False v = bumpVersion v
650 %*********************************************************
652 \subsection{Keeping track of what we've slurped, and version numbers}
654 %*********************************************************
658 mkUsageInfo :: HscEnv -> ImportAvails -> NameSet -> IO [Usage]
660 (ImportAvails { imp_mods = dir_imp_mods,
661 imp_dep_mods = dep_mods })
663 = do { eps <- hscEPS hsc_env
664 ; return (mk_usage_info (eps_PIT eps) (hsc_HPT hsc_env)
665 dir_imp_mods dep_mods used_names) }
667 mk_usage_info pit hpt dir_imp_mods dep_mods proto_used_names
668 = -- seq the list of Usages returned: occasionally these
669 -- don't get evaluated for a while and we can end up hanging on to
670 -- the entire collection of Ifaces.
671 usages `seqList` usages
673 used_names = mkNameSet $ -- Eliminate duplicates
674 [ nameParent n -- Just record usage on the 'main' names
675 | n <- nameSetToList proto_used_names
676 , not (isWiredInName n) -- Don't record usages for wired-in names
677 , isExternalName n -- Ignore internal names
680 -- ent_map groups together all the things imported and used
681 -- from a particular module in this package
682 ent_map :: ModuleEnv [OccName]
683 ent_map = foldNameSet add_mv emptyModuleEnv used_names
684 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
686 occ = nameOccName name
687 mod = nameModule name
688 add_item occs _ = occ:occs
690 usages = mapCatMaybes mkUsage (moduleEnvElts dep_mods)
691 -- ToDo: do we need to sort into canonical order?
693 import_all mod = case lookupModuleEnv dir_imp_mods mod of
694 Just (_,imp_all) -> isNothing imp_all
697 -- We want to create a Usage for a home module if
698 -- a) we used something from; has something in used_names
699 -- b) we imported all of it, even if we used nothing from it
700 -- (need to recompile if its export list changes: export_vers)
701 -- c) is a home-package orphan module (need to recompile if its
702 -- instance decls change: rules_vers)
703 mkUsage :: (ModuleName, Bool) -> Maybe Usage
704 mkUsage (mod_name, _)
705 | isNothing maybe_iface -- We can't depend on it if we didn't
706 || not (isHomeModule mod) -- even open the interface!
710 = Nothing -- Record no usage info
713 = Just (Usage { usg_name = moduleName mod,
715 usg_exports = export_vers,
716 usg_entities = ent_vers,
717 usg_rules = rules_vers })
719 maybe_iface = lookupIfaceByModName hpt pit mod_name
720 -- In one-shot mode, the interfaces for home-package
721 -- modules accumulate in the PIT not HPT. Sigh.
723 Just iface = maybe_iface
724 mod = mi_module iface
725 orphan_mod = mi_orphan iface
726 version_env = mi_ver_fn iface
727 mod_vers = mi_mod_vers iface
728 rules_vers = mi_rule_vers iface
729 all_imported = import_all mod
730 export_vers | all_imported = Just (mi_exp_vers iface)
731 | otherwise = Nothing
733 -- The sort is to put them into canonical order
734 used_occs = lookupModuleEnv ent_map mod `orElse` []
735 ent_vers :: [(OccName,Version)]
736 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
737 | occ <- sortLt (<) used_occs]
741 mkIfaceExports :: NameSet -> [(ModuleName, [GenAvailInfo OccName])]
742 -- Group by module and sort by occurrence
743 -- This keeps the list in canonical order
744 mkIfaceExports exports
745 = [ (mkSysModuleNameFS fs, eltsFM avails)
746 | (fs, avails) <- fmToList groupFM
749 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
750 -- Deliberately use the FastString so we
751 -- get a canonical ordering
752 groupFM = foldl add emptyFM (nameSetToList exports)
754 add env name = addToFM_C add_avail env mod_fs
755 (unitFM avail_fs avail)
757 occ = nameOccName name
758 occ_fs = occNameFS occ
759 mod_fs = moduleNameFS (nameModuleName name)
760 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
761 | isTcOcc occ = AvailTC occ [occ]
762 | otherwise = Avail occ
763 avail_fs = occNameFS (availName avail)
764 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
766 add_item (AvailTC p occs) _ = AvailTC p (insert occ occs)
767 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
771 %************************************************************************
773 Load the old interface file for this module (unless
774 we have it aleady), and check whether it is up to date
777 %************************************************************************
780 checkOldIface :: HscEnv
782 -> FilePath -- Where the interface file is
783 -> Bool -- Source unchanged
784 -> Maybe ModIface -- Old interface from compilation manager, if any
785 -> IO (RecompileRequired, Maybe ModIface)
787 checkOldIface hsc_env mod iface_path source_unchanged maybe_iface
788 = do { showPass (hsc_dflags hsc_env)
789 ("Checking old interface for " ++ moduleUserString mod) ;
791 ; initIfaceCheck hsc_env $
792 check_old_iface mod iface_path source_unchanged maybe_iface
795 check_old_iface this_mod iface_path source_unchanged maybe_iface
796 = -- CHECK WHETHER THE SOURCE HAS CHANGED
797 ifM (not source_unchanged)
798 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
801 -- If the source has changed and we're in interactive mode, avoid reading
802 -- an interface; just return the one we might have been supplied with.
803 getGhciMode `thenM` \ ghci_mode ->
804 if (ghci_mode == Interactive) && not source_unchanged then
805 returnM (outOfDate, maybe_iface)
808 case maybe_iface of {
809 Just old_iface -> -- Use the one we already have
810 checkVersions source_unchanged old_iface `thenM` \ recomp ->
811 returnM (recomp, Just old_iface)
815 -- Try and read the old interface for the current module
816 -- from the .hi file left from the last time we compiled it
817 readIface (moduleName this_mod) iface_path False `thenM` \ read_result ->
818 case read_result of {
819 Left err -> -- Old interface file not found, or garbled; give up
820 traceIf (text "FYI: cannot read old interface file:"
821 $$ nest 4 err) `thenM_`
822 returnM (outOfDate, Nothing)
826 -- We have got the old iface; check its versions
827 checkVersions source_unchanged iface `thenM` \ recomp ->
828 returnM (recomp, Just iface)
832 @recompileRequired@ is called from the HscMain. It checks whether
833 a recompilation is required. It needs access to the persistent state,
834 finder, etc, because it may have to load lots of interface files to
835 check their versions.
838 type RecompileRequired = Bool
839 upToDate = False -- Recompile not required
840 outOfDate = True -- Recompile required
842 checkVersions :: Bool -- True <=> source unchanged
843 -> ModIface -- Old interface
844 -> IfG RecompileRequired
845 checkVersions source_unchanged iface
846 | not source_unchanged
849 = traceHiDiffs (text "Considering whether compilation is required for" <+>
850 ppr (mi_module iface) <> colon) `thenM_`
852 -- Source code unchanged and no errors yet... carry on
853 -- First put the dependent-module info in the envt, just temporarily,
854 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
855 -- It's just temporary because either the usage check will succeed
856 -- (in which case we are done with this module) or it'll fail (in which
857 -- case we'll compile the module from scratch anyhow).
858 updGblEnv (\ gbl -> gbl { if_is_boot = mod_deps }) (
859 checkList [checkModUsage u | u <- mi_usages iface]
862 -- This is a bit of a hack really
863 mod_deps :: ModuleEnv (ModuleName, IsBootInterface)
864 mod_deps = mkModDeps (dep_mods (mi_deps iface))
866 checkModUsage :: Usage -> IfG RecompileRequired
867 -- Given the usage information extracted from the old
868 -- M.hi file for the module being compiled, figure out
869 -- whether M needs to be recompiled.
871 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
872 usg_rules = old_rule_vers,
873 usg_exports = maybe_old_export_vers,
874 usg_entities = old_decl_vers })
875 = -- Load the imported interface is possible
877 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
879 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
881 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
882 -- Load the interface, but don't complain on failure;
883 -- Instead, get an Either back which we can test
886 Left exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
888 -- Couldn't find or parse a module mentioned in the
889 -- old interface file. Don't complain -- it might just be that
890 -- the current module doesn't need that import and it's been deleted
894 new_mod_vers = mi_mod_vers iface
895 new_decl_vers = mi_ver_fn iface
896 new_export_vers = mi_exp_vers iface
897 new_rule_vers = mi_rule_vers iface
900 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
901 if not recompile then
906 if checkExportList maybe_old_export_vers new_export_vers then
907 out_of_date_vers (ptext SLIT(" Export list changed"))
908 (fromJust maybe_old_export_vers)
913 if old_rule_vers /= new_rule_vers then
914 out_of_date_vers (ptext SLIT(" Rules changed"))
915 old_rule_vers new_rule_vers
918 -- CHECK ITEMS ONE BY ONE
919 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
921 returnM outOfDate -- This one failed, so just bail out now
923 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
926 ------------------------
927 checkModuleVersion old_mod_vers new_mod_vers
928 | new_mod_vers == old_mod_vers
929 = up_to_date (ptext SLIT("Module version unchanged"))
932 = out_of_date_vers (ptext SLIT(" Module version has changed"))
933 old_mod_vers new_mod_vers
935 ------------------------
936 checkExportList Nothing new_vers = upToDate
937 checkExportList (Just v) new_vers = v /= new_vers
939 ------------------------
940 checkEntityUsage new_vers (name,old_vers)
941 = case new_vers name of
943 Nothing -> -- We used it before, but it ain't there now
944 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
946 Just new_vers -- It's there, but is it up to date?
947 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
949 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
952 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
953 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
954 out_of_date_vers msg old_vers new_vers
955 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
957 ----------------------
958 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
959 -- This helper is used in two places
960 checkList [] = returnM upToDate
961 checkList (check:checks) = check `thenM` \ recompile ->
968 %************************************************************************
972 %************************************************************************
975 showIface :: FilePath -> IO ()
976 -- Raad binary interface, and print it out
977 showIface filename = do
978 -- skip the version check; we don't want to worry about profiled vs.
979 -- non-profiled interfaces, for example.
980 writeIORef v_IgnoreHiWay True
981 iface <- Binary.getBinFileWithDict filename
982 printDump (pprModIface iface)
988 pprModIface :: ModIface -> SDoc
991 = vcat [ ptext SLIT("interface")
992 <+> doubleQuotes (ftext (mi_package iface))
993 <+> ppr (mi_module iface) <+> ppr (mi_mod_vers iface)
995 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
996 <+> int opt_HiVersion
997 <+> ptext SLIT("where")
998 , vcat (map pprExport (mi_exports iface))
999 , pprDeps (mi_deps iface)
1000 , vcat (map pprUsage (mi_usages iface))
1001 , pprFixities (mi_fixities iface)
1002 , vcat (map pprIfaceDecl (mi_decls iface))
1003 , vcat (map ppr (mi_insts iface))
1004 , vcat (map ppr (mi_rules iface))
1005 , pprDeprecs (mi_deprecs iface)
1008 exp_vers = mi_exp_vers iface
1009 rule_vers = mi_rule_vers iface
1011 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1012 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1015 When printing export lists, we print like this:
1017 AvailTC C [C, x, y] C(x,y)
1018 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1021 pprExport :: IfaceExport -> SDoc
1022 pprExport (mod, items)
1023 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1025 pp_avail :: GenAvailInfo OccName -> SDoc
1026 pp_avail (Avail occ) = ppr occ
1027 pp_avail (AvailTC _ []) = empty
1028 pp_avail (AvailTC n (n':ns))
1029 | n==n' = ppr n <> pp_export ns
1030 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1032 pp_export [] = empty
1033 pp_export names = braces (hsep (map ppr names))
1035 pprUsage :: Usage -> SDoc
1037 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1038 int (usg_mod usage),
1039 pp_export_version (usg_exports usage),
1040 int (usg_rules usage),
1041 pp_versions (usg_entities usage) ]
1043 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1044 pp_export_version Nothing = empty
1045 pp_export_version (Just v) = int v
1047 pprDeps :: Dependencies -> SDoc
1048 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1049 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1050 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1051 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1054 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1055 ppr_boot True = text "[boot]"
1056 ppr_boot False = empty
1058 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1059 pprIfaceDecl (ver, decl)
1060 = ppr_vers ver <+> ppr decl
1062 -- Print the version for the decl
1063 ppr_vers v | v == initialVersion = empty
1066 pprFixities :: [(OccName, Fixity)] -> SDoc
1067 pprFixities [] = empty
1068 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1070 pprFix (occ,fix) = ppr fix <+> ppr occ
1072 pprDeprecs NoDeprecs = empty
1073 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1074 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1076 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)