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(..),
187 ModGuts(..), ModGuts, IfaceExport,
190 Dependencies(..), FixItem(..),
192 mkIfaceDepCache, mkIfaceFixCache, mkIfaceVerCache,
194 Avails, AvailInfo, GenAvailInfo(..), availName,
195 ExternalPackageState(..),
196 Usage(..), IsBootInterface,
197 Deprecs(..), IfaceDeprecs, Deprecations,
203 import Name ( Name, nameModule, nameOccName, nameParent, isExternalName,
204 nameParent_maybe, isWiredInName, NamedThing(..) )
207 import OccName ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv_C,
208 OccSet, emptyOccSet, elemOccSet, occSetElts,
209 extendOccSet, extendOccSetList,
210 isEmptyOccSet, intersectOccSet, intersectsOccSet )
211 import TyCon ( visibleDataCons )
212 import Module ( Module, ModuleName, moduleNameFS, moduleName, isHomeModule,
213 ModLocation(..), mkSysModuleNameFS, moduleUserString,
214 ModuleEnv, emptyModuleEnv, lookupModuleEnv,
215 extendModuleEnv_C, moduleEnvElts
218 import DriverUtil ( createDirectoryHierarchy, directoryOf )
219 import Util ( sortLt, seqList )
220 import Binary ( getBinFileWithDict )
221 import BinIface ( writeBinIface, v_IgnoreHiWay )
222 import Unique ( Unique, Uniquable(..) )
223 import ErrUtils ( dumpIfSet_dyn, showPass )
224 import Digraph ( stronglyConnComp, SCC(..) )
228 import DATA_IOREF ( writeIORef )
229 import Monad ( when )
230 import Maybes ( orElse, mapCatMaybes, isNothing, fromJust, expectJust )
235 %************************************************************************
237 \subsection{Completing an interface}
239 %************************************************************************
244 -> Maybe ModIface -- The old interface, if we have it
245 -> ModGuts -- The compiled, tidied module
246 -> IO ModIface -- The new one, complete with decls and versions
248 -- a) completes the interface
249 -- b) writes it out to a file if necessary
251 mkIface hsc_env location maybe_old_iface
252 guts@ModGuts{ mg_module = this_mod,
255 mg_exports = exports,
256 mg_fix_env = fix_env,
257 mg_deprecs = src_deprecs,
260 mg_types = type_env }
261 = do { eps <- hscEPS hsc_env
262 ; let { this_mod_name = moduleName this_mod
263 ; ext_nm = mkExtNameFn hsc_env eps this_mod_name
264 ; decls = [ tyThingToIfaceDecl omit_prags ext_nm thing
265 | thing <- typeEnvElts type_env
266 , not (isImplicitTyThing thing) && not (isWiredInName (getName thing)) ]
267 -- Don't put implicit Ids and class tycons in the interface file
268 -- Nor wired-in things (GHC knows about them already)
270 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
271 ; deprecs = mkIfaceDeprec src_deprecs
274 | otherwise = sortLt lt_rule $
275 map (coreRuleToIfaceRule this_mod_name ext_nm) rules
276 ; iface_insts = sortLt lt_inst (map (dfunToIfaceInst this_mod_name) insts)
278 ; intermediate_iface = ModIface {
279 mi_module = this_mod,
280 mi_package = opt_InPackage,
284 mi_exports = groupAvails exports,
285 mi_insts = iface_insts,
286 mi_rules = iface_rules,
287 mi_fixities = fixities,
288 mi_deprecs = deprecs,
290 -- Left out deliberately: filled in by addVersionInfo
291 mi_mod_vers = initialVersion,
292 mi_exp_vers = initialVersion,
293 mi_rule_vers = initialVersion,
294 mi_orphan = False, -- Always set by addVersionInfo, but
295 -- it's a strict field, so we can't omit it.
296 mi_decls = deliberatelyOmitted "decls",
297 mi_ver_fn = deliberatelyOmitted "ver_fn",
299 -- And build the cached values
300 mi_dep_fn = mkIfaceDepCache deprecs,
301 mi_fix_fn = mkIfaceFixCache fixities }
303 -- Add version information
304 ; (new_iface, no_change_at_all, pp_diffs)
305 = _scc_ "versioninfo"
306 addVersionInfo maybe_old_iface intermediate_iface decls
309 -- Write the interface file, if necessary
310 ; when (not no_change_at_all && ghci_mode /= Interactive) $ do
311 createDirectoryHierarchy (directoryOf hi_file_path)
312 writeBinIface hi_file_path new_iface
315 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
316 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
317 (pprModIface new_iface)
321 r1 `lt_rule` r2 = ifRuleName r1 < ifRuleName r2
322 i1 `lt_inst` i2 = ifDFun i1 < ifDFun i2
324 dflags = hsc_dflags hsc_env
325 ghci_mode = hsc_mode hsc_env
326 hi_file_path = ml_hi_file location
327 omit_prags = dopt Opt_OmitInterfacePragmas dflags
329 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
331 -----------------------------
332 mkExtNameFn :: HscEnv -> ExternalPackageState -> ModuleName -> Name -> IfaceExtName
333 mkExtNameFn hsc_env eps this_mod
336 hpt = hsc_HPT hsc_env
340 | mod_nm == this_mod = case nameParent_maybe name of
341 Nothing -> LocalTop occ
342 Just par -> LocalTopSub occ (nameOccName par)
343 | isWiredInName name = ExtPkg mod_nm occ
344 | isHomeModule mod = HomePkg mod_nm occ vers
345 | otherwise = ExtPkg mod_nm occ
347 mod = nameModule name
348 mod_nm = moduleName mod
349 occ = nameOccName name
350 par_occ = nameOccName (nameParent name)
351 -- The version of the *parent* is the one want
352 vers = lookupVersion mod_nm par_occ
354 lookupVersion :: ModuleName -> OccName -> Version
355 -- Even though we're looking up a home-package thing, in
356 -- one-shot mode the imported interfaces may be in the PIT
357 lookupVersion mod occ
358 = mi_ver_fn iface occ `orElse`
359 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
361 iface = lookupIfaceByModName hpt pit mod `orElse`
362 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
364 -----------------------------
365 -- Compute version numbers for local decls
367 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
368 -> ModIface -- The new interface decls (lacking decls)
369 -> [IfaceDecl] -- The new decls
371 Bool, -- True <=> no changes at all; no need to write new Iface
374 addVersionInfo Nothing new_iface new_decls
375 -- No old interface, so definitely write a new one!
376 = (new_iface { mi_orphan = anyNothing getInstKey (mi_insts new_iface)
377 || anyNothing getRuleKey (mi_rules new_iface),
378 mi_decls = [(initialVersion, decl) | decl <- new_decls],
379 mi_ver_fn = \n -> Just initialVersion },
380 False, ptext SLIT("No old interface file") $$
381 pprOrphans orph_insts orph_rules)
383 orph_insts = filter (isNothing . getInstKey) (mi_insts new_iface)
384 orph_rules = filter (isNothing . getRuleKey) (mi_rules new_iface)
386 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
387 mi_exp_vers = old_exp_vers,
388 mi_rule_vers = old_rule_vers,
389 mi_decls = old_decls,
390 mi_ver_fn = old_decl_vers,
391 mi_fix_fn = old_fixities }))
392 new_iface@(ModIface { mi_fix_fn = new_fixities })
395 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged") $$ pp_orphs)
396 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
398 text "" $$ pp_orphs])
400 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
401 mi_exp_vers = bump_unless no_export_change old_exp_vers,
402 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
403 mi_orphan = not (null new_orph_rules && null new_orph_insts),
404 mi_decls = decls_w_vers,
405 mi_ver_fn = mkIfaceVerCache decls_w_vers }
407 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
410 (old_non_orph_insts, old_orph_insts) = mkRuleMap getInstKey (mi_insts old_iface)
411 (new_non_orph_insts, new_orph_insts) = mkRuleMap getInstKey (mi_insts new_iface)
412 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
413 (lookupOccEnv old_non_orph_insts occ)
414 (lookupOccEnv new_non_orph_insts occ)
416 (old_non_orph_rules, old_orph_rules) = mkRuleMap getRuleKey (mi_rules old_iface)
417 (new_non_orph_rules, new_orph_rules) = mkRuleMap getRuleKey (mi_rules new_iface)
418 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
419 (lookupOccEnv old_non_orph_rules occ)
420 (lookupOccEnv new_non_orph_rules occ)
422 -- Computing what changed
423 no_output_change = no_decl_change && no_rule_change &&
424 no_export_change && no_deprec_change
425 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
426 no_decl_change = isEmptyOccSet changed_occs
427 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
428 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
429 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
431 -- If the usages havn't changed either, we don't need to write the interface file
432 -- Question: should we also check for equality of mi_deps?
433 no_other_changes = mi_usages new_iface == mi_usages old_iface
434 no_change_at_all = no_output_change && no_other_changes
436 pp_diffs = vcat [pp_change no_export_change "Export list"
437 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
438 pp_change no_rule_change "Rules"
439 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
440 pp_change no_deprec_change "Deprecations" empty,
441 pp_change no_other_changes "Usages" empty,
443 pp_change True what info = empty
444 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
447 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
448 same_fixity n = bool (old_fixities n == new_fixities n)
451 -- Adding version info
452 new_version = bumpVersion old_mod_vers
453 add_vers decl | occ `elemOccSet` changed_occs = new_version
454 | otherwise = expectJust "add_vers" (old_decl_vers occ)
455 -- If it's unchanged, there jolly well
456 where -- should be an old version number
460 changed_occs :: OccSet
461 changed_occs = computeChangedOccs eq_info
463 eq_info :: [(OccName, IfaceEq)]
464 eq_info = map check_eq new_decls
465 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
466 = (occ, new_decl `eqIfDecl` old_decl &&&
467 eq_indirects new_decl)
468 | otherwise {- No corresponding old decl -}
471 occ = ifName new_decl
473 eq_indirects :: IfaceDecl -> IfaceEq
474 -- When seeing if two decls are the same, remember to
475 -- check whether any relevant fixity or rules have changed
476 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
477 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
478 = same_insts cls_occ &&&
479 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
480 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
481 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
482 eq_ind_occs [occ | IfaceConDecl occ _ _ _ _ _ <- visibleDataCons cons]
483 eq_indirects other = Equal -- Synonyms and foreign declarations
485 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
486 eq_ind_occ occ = same_fixity occ &&& same_rules occ
487 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
491 pp_decl_diffs :: SDoc -- Nothing => no changes
493 | isEmptyOccSet changed_occs = empty
495 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
496 ptext SLIT("Version change for these decls:"),
497 nest 2 (vcat (map show_change new_decls))]
499 eq_env = mkOccEnv eq_info
501 | not (occ `elemOccSet` changed_occs) = empty
503 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
506 occ = ifName new_decl
507 why = case lookupOccEnv eq_env occ of
508 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
509 nest 2 (braces (fsep (map ppr (occSetElts
510 (occs `intersectOccSet` changed_occs)))))]
512 | Just old_decl <- lookupOccEnv old_decl_env occ
513 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
514 ptext SLIT("New:") <+> ppr new_decl]
516 -> ppr occ <+> ptext SLIT("only in new interface")
517 other -> pprPanic "MkIface.show_change" (ppr occ)
519 pp_orphs = pprOrphans new_orph_insts new_orph_rules
521 pprOrphans insts rules
522 = vcat [if null insts then empty else
523 ptext SLIT("Orphan instances:") <+> vcat (map ppr insts),
524 if null rules then empty else
525 ptext SLIT("Orphan rules:") <+> vcat (map ppr rules)]
527 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
528 computeChangedOccs eq_info
529 = foldl add_changes emptyOccSet (stronglyConnComp edges)
531 edges :: [((OccName,IfaceEq), Unique, [Unique])]
532 edges = [ (node, getUnique occ, map getUnique occs)
533 | node@(occ, iface_eq) <- eq_info
534 , let occs = case iface_eq of
535 EqBut occ_set -> occSetElts occ_set
538 -- Changes in declarations
539 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
540 add_changes so_far (AcyclicSCC (occ, iface_eq))
541 | changedWrt so_far iface_eq -- This one has changed
542 = extendOccSet so_far occ
543 add_changes so_far (CyclicSCC pairs)
544 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
545 = extendOccSetList so_far (map fst pairs)
546 add_changes so_far other = so_far
548 changedWrt :: OccSet -> IfaceEq -> Bool
549 changedWrt so_far Equal = False
550 changedWrt so_far NotEqual = True
551 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
553 ----------------------
554 -- mkRuleMap partitions instance decls or rules into
555 -- (a) an OccEnv for ones that are not orphans,
556 -- mapping the local OccName to a list of its decls
557 -- (b) a list of orphan decls
558 mkRuleMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
559 -- Nothing for an orphan decl
560 -> [decl] -- Sorted into canonical order
561 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
562 -- each sublist in canonical order
563 [decl]) -- Orphan decls; in canonical order
564 mkRuleMap get_key decls
565 = foldl go (emptyOccEnv, []) decls
567 go (non_orphs, orphs) d
568 | Just occ <- get_key d
569 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
570 | otherwise = (non_orphs, d:orphs)
572 -- getXxKey: find at least one local OccName that belongs to this decl
574 getInstKey :: IfaceInst -> Maybe OccName
575 getInstKey (IfaceInst {ifInstHead = inst_ty})
576 = case [occ | LocalTop occ <- cls_ext : tc_exts] of
580 (cls_ext, tcs) = ifaceInstGates inst_ty
581 tc_exts = [tc | IfaceTc tc <- tcs]
582 -- Ignore the wired-in IfaceTyCons; the class will do as the key
584 getRuleKey :: IfaceRule -> Maybe OccName
585 getRuleKey (IfaceRule {ifRuleHead = LocalTop occ}) = Just occ
586 getRuleKey other = Nothing
588 anyNothing :: (a -> Maybe b) -> [a] -> Bool
589 anyNothing p [] = False
590 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
592 ----------------------
593 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
594 mkIfaceDeprec NoDeprecs = NoDeprecs
595 mkIfaceDeprec (DeprecAll t) = DeprecAll t
596 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLt (<) (nameEnvElts env))
598 ----------------------
599 bump_unless :: Bool -> Version -> Version
600 bump_unless True v = v -- True <=> no change
601 bump_unless False v = bumpVersion v
605 %*********************************************************
607 \subsection{Keeping track of what we've slurped, and version numbers}
609 %*********************************************************
613 mkUsageInfo :: HscEnv -> ImportAvails -> NameSet -> IO [Usage]
615 (ImportAvails { imp_mods = dir_imp_mods,
616 imp_dep_mods = dep_mods })
618 = do { eps <- hscEPS hsc_env
619 ; return (mk_usage_info (eps_PIT eps) (hsc_HPT hsc_env)
620 dir_imp_mods dep_mods used_names) }
622 mk_usage_info pit hpt dir_imp_mods dep_mods proto_used_names
623 = -- seq the list of Usages returned: occasionally these
624 -- don't get evaluated for a while and we can end up hanging on to
625 -- the entire collection of Ifaces.
626 usages `seqList` usages
628 used_names = mkNameSet $ -- Eliminate duplicates
629 [ nameParent n -- Just record usage on the 'main' names
630 | n <- nameSetToList proto_used_names
631 , not (isWiredInName n) -- Don't record usages for wired-in names
632 , isExternalName n -- Ignore internal names
635 -- ent_map groups together all the things imported and used
636 -- from a particular module in this package
637 ent_map :: ModuleEnv [OccName]
638 ent_map = foldNameSet add_mv emptyModuleEnv used_names
639 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
641 occ = nameOccName name
642 mod = nameModule name
643 add_item occs _ = occ:occs
645 usages = mapCatMaybes mkUsage (moduleEnvElts dep_mods)
646 -- ToDo: do we need to sort into canonical order?
648 import_all mod = case lookupModuleEnv dir_imp_mods mod of
649 Just (_,imp_all) -> isNothing imp_all
652 -- We want to create a Usage for a home module if
653 -- a) we used something from; has something in used_names
654 -- b) we imported all of it, even if we used nothing from it
655 -- (need to recompile if its export list changes: export_vers)
656 -- c) is a home-package orphan module (need to recompile if its
657 -- instance decls change: rules_vers)
658 mkUsage :: (ModuleName, Bool) -> Maybe Usage
659 mkUsage (mod_name, _)
660 | isNothing maybe_iface -- We can't depend on it if we didn't
661 || not (isHomeModule mod) -- even open the interface!
665 = Nothing -- Record no usage info
668 = Just (Usage { usg_name = moduleName mod,
670 usg_exports = export_vers,
671 usg_entities = ent_vers,
672 usg_rules = rules_vers })
674 maybe_iface = lookupIfaceByModName hpt pit mod_name
675 -- In one-shot mode, the interfaces for home-package
676 -- modules accumulate in the PIT not HPT. Sigh.
678 Just iface = maybe_iface
679 mod = mi_module iface
680 orphan_mod = mi_orphan iface
681 version_env = mi_ver_fn iface
682 mod_vers = mi_mod_vers iface
683 rules_vers = mi_rule_vers iface
684 all_imported = import_all mod
685 export_vers | all_imported = Just (mi_exp_vers iface)
686 | otherwise = Nothing
688 -- The sort is to put them into canonical order
689 used_occs = lookupModuleEnv ent_map mod `orElse` []
690 ent_vers :: [(OccName,Version)]
691 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
692 | occ <- sortLt (<) used_occs]
696 groupAvails :: Avails -> [(ModuleName, [GenAvailInfo OccName])]
697 -- Group by module and sort by occurrence
698 -- This keeps the list in canonical order
700 = [ (mkSysModuleNameFS fs, sortLt lt avails)
701 | (fs,avails) <- fmToList groupFM
704 groupFM :: FiniteMap FastString [GenAvailInfo OccName]
705 -- Deliberately use the FastString so we
706 -- get a canonical ordering
707 groupFM = foldl add emptyFM avails
709 add env avail = addToFM_C (\old _ -> avail':old) env mod_fs [avail']
711 mod_fs = moduleNameFS (moduleName avail_mod)
712 avail_mod = nameModule (availName avail)
713 avail' = sortAvail avail
715 a1 `lt` a2 = availName a1 < availName a2
717 sortAvail :: AvailInfo -> GenAvailInfo OccName
718 -- Convert to OccName, and sort the sub-names into canonical order
719 -- The canonical order has the "main name" at the beginning
720 -- (if it's there at all)
721 sortAvail (Avail n) = Avail (nameOccName n)
722 sortAvail (AvailTC n ns)
723 | n `elem` ns = AvailTC occ (occ : mk_occs (filter (/= n) ns))
724 | otherwise = AvailTC occ ( mk_occs ns)
727 mk_occs ns = sortLt (<) (map nameOccName ns)
730 %************************************************************************
732 Load the old interface file for this module (unless
733 we have it aleady), and check whether it is up to date
736 %************************************************************************
739 checkOldIface :: HscEnv
741 -> FilePath -- Where the interface file is
742 -> Bool -- Source unchanged
743 -> Maybe ModIface -- Old interface from compilation manager, if any
744 -> IO (RecompileRequired, Maybe ModIface)
746 checkOldIface hsc_env mod iface_path source_unchanged maybe_iface
747 = do { showPass (hsc_dflags hsc_env)
748 ("Checking old interface for " ++ moduleUserString mod) ;
750 ; initIfaceCheck hsc_env $
751 check_old_iface mod iface_path source_unchanged maybe_iface
754 check_old_iface this_mod iface_path source_unchanged maybe_iface
755 = -- CHECK WHETHER THE SOURCE HAS CHANGED
756 ifM (not source_unchanged)
757 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
760 -- If the source has changed and we're in interactive mode, avoid reading
761 -- an interface; just return the one we might have been supplied with.
762 getGhciMode `thenM` \ ghci_mode ->
763 if (ghci_mode == Interactive) && not source_unchanged then
764 returnM (outOfDate, maybe_iface)
767 case maybe_iface of {
768 Just old_iface -> -- Use the one we already have
769 checkVersions source_unchanged old_iface `thenM` \ recomp ->
770 returnM (recomp, Just old_iface)
774 -- Try and read the old interface for the current module
775 -- from the .hi file left from the last time we compiled it
776 readIface (moduleName this_mod) iface_path False `thenM` \ read_result ->
777 case read_result of {
778 Left err -> -- Old interface file not found, or garbled; give up
779 traceIf (text "FYI: cannot read old interface file:"
780 $$ nest 4 err) `thenM_`
781 returnM (outOfDate, Nothing)
785 -- We have got the old iface; check its versions
786 checkVersions source_unchanged iface `thenM` \ recomp ->
787 returnM (recomp, Just iface)
791 @recompileRequired@ is called from the HscMain. It checks whether
792 a recompilation is required. It needs access to the persistent state,
793 finder, etc, because it may have to load lots of interface files to
794 check their versions.
797 type RecompileRequired = Bool
798 upToDate = False -- Recompile not required
799 outOfDate = True -- Recompile required
801 checkVersions :: Bool -- True <=> source unchanged
802 -> ModIface -- Old interface
803 -> IfG RecompileRequired
804 checkVersions source_unchanged iface
805 | not source_unchanged
808 = traceHiDiffs (text "Considering whether compilation is required for" <+>
809 ppr (mi_module iface) <> colon) `thenM_`
811 -- Source code unchanged and no errors yet... carry on
812 -- First put the dependent-module info in the envt, just temporarily,
813 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
814 -- It's just temporary because either the usage check will succeed
815 -- (in which case we are done with this module) or it'll fail (in which
816 -- case we'll compile the module from scratch anyhow).
817 updGblEnv (\ gbl -> gbl { if_is_boot = mod_deps }) (
818 checkList [checkModUsage u | u <- mi_usages iface]
821 -- This is a bit of a hack really
822 mod_deps :: ModuleEnv (ModuleName, IsBootInterface)
823 mod_deps = mkModDeps (dep_mods (mi_deps iface))
825 checkModUsage :: Usage -> IfG RecompileRequired
826 -- Given the usage information extracted from the old
827 -- M.hi file for the module being compiled, figure out
828 -- whether M needs to be recompiled.
830 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
831 usg_rules = old_rule_vers,
832 usg_exports = maybe_old_export_vers,
833 usg_entities = old_decl_vers })
834 = -- Load the imported interface is possible
836 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
838 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
840 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
841 -- Load the interface, but don't complain on failure;
842 -- Instead, get an Either back which we can test
845 Left exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
847 -- Couldn't find or parse a module mentioned in the
848 -- old interface file. Don't complain -- it might just be that
849 -- the current module doesn't need that import and it's been deleted
853 new_mod_vers = mi_mod_vers iface
854 new_decl_vers = mi_ver_fn iface
855 new_export_vers = mi_exp_vers iface
856 new_rule_vers = mi_rule_vers iface
859 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
860 if not recompile then
865 if checkExportList maybe_old_export_vers new_export_vers then
866 out_of_date_vers (ptext SLIT(" Export list changed"))
867 (fromJust maybe_old_export_vers)
872 if old_rule_vers /= new_rule_vers then
873 out_of_date_vers (ptext SLIT(" Rules changed"))
874 old_rule_vers new_rule_vers
877 -- CHECK ITEMS ONE BY ONE
878 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
880 returnM outOfDate -- This one failed, so just bail out now
882 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
885 ------------------------
886 checkModuleVersion old_mod_vers new_mod_vers
887 | new_mod_vers == old_mod_vers
888 = up_to_date (ptext SLIT("Module version unchanged"))
891 = out_of_date_vers (ptext SLIT(" Module version has changed"))
892 old_mod_vers new_mod_vers
894 ------------------------
895 checkExportList Nothing new_vers = upToDate
896 checkExportList (Just v) new_vers = v /= new_vers
898 ------------------------
899 checkEntityUsage new_vers (name,old_vers)
900 = case new_vers name of
902 Nothing -> -- We used it before, but it ain't there now
903 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
905 Just new_vers -- It's there, but is it up to date?
906 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
908 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
911 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
912 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
913 out_of_date_vers msg old_vers new_vers
914 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
916 ----------------------
917 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
918 -- This helper is used in two places
919 checkList [] = returnM upToDate
920 checkList (check:checks) = check `thenM` \ recompile ->
927 %************************************************************************
931 %************************************************************************
934 showIface :: FilePath -> IO ()
935 -- Raad binary interface, and print it out
936 showIface filename = do
937 -- skip the version check; we don't want to worry about profiled vs.
938 -- non-profiled interfaces, for example.
939 writeIORef v_IgnoreHiWay True
940 iface <- Binary.getBinFileWithDict filename
941 printDump (pprModIface iface)
947 pprModIface :: ModIface -> SDoc
950 = vcat [ ptext SLIT("interface")
951 <+> doubleQuotes (ftext (mi_package iface))
952 <+> ppr (mi_module iface) <+> ppr (mi_mod_vers iface)
954 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
955 <+> int opt_HiVersion
956 <+> ptext SLIT("where")
957 , vcat (map pprExport (mi_exports iface))
958 , pprDeps (mi_deps iface)
959 , vcat (map pprUsage (mi_usages iface))
960 , pprFixities (mi_fixities iface)
961 , vcat (map pprIfaceDecl (mi_decls iface))
962 , vcat (map ppr (mi_insts iface))
963 , vcat (map ppr (mi_rules iface))
964 , pprDeprecs (mi_deprecs iface)
967 exp_vers = mi_exp_vers iface
968 rule_vers = mi_rule_vers iface
970 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
971 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
974 When printing export lists, we print like this:
976 AvailTC C [C, x, y] C(x,y)
977 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
980 pprExport :: IfaceExport -> SDoc
981 pprExport (mod, items)
982 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
984 pp_avail :: GenAvailInfo OccName -> SDoc
985 pp_avail (Avail occ) = ppr occ
986 pp_avail (AvailTC _ []) = empty
987 pp_avail (AvailTC n (n':ns))
988 | n==n' = ppr n <> pp_export ns
989 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
992 pp_export names = braces (hsep (map ppr names))
994 pprUsage :: Usage -> SDoc
996 = hsep [ptext SLIT("import"), ppr (usg_name usage),
998 pp_export_version (usg_exports usage),
999 int (usg_rules usage),
1000 pp_versions (usg_entities usage) ]
1002 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1003 pp_export_version Nothing = empty
1004 pp_export_version (Just v) = int v
1006 pprDeps :: Dependencies -> SDoc
1007 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1008 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1009 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1010 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1013 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1014 ppr_boot True = text "[boot]"
1015 ppr_boot False = empty
1017 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1018 pprIfaceDecl (ver, decl)
1019 = ppr_vers ver <+> ppr decl
1021 -- Print the version for the decl
1022 ppr_vers v | v == initialVersion = empty
1025 pprFixities :: [(OccName, Fixity)] -> SDoc
1026 pprFixities [] = empty
1027 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1029 pprFix (occ,fix) = ppr fix <+> ppr occ
1031 pprDeprecs NoDeprecs = empty
1032 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1033 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1035 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)