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 Packages ( isHomeModule )
178 import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..),
179 IfaceRule(..), IfaceInst(..), IfaceExtName(..), IfaceTyCon(..),
180 eqIfDecl, eqIfRule, eqIfInst, IfaceEq(..), (&&&), bool,
181 eqMaybeBy, eqListBy, visibleIfConDecls,
182 tyThingToIfaceDecl, dfunToIfaceInst, coreRuleToIfaceRule )
183 import LoadIface ( readIface, loadInterface, ifaceInstGates )
184 import BasicTypes ( Version, initialVersion, bumpVersion )
186 import TcRnTypes ( mkModDeps )
187 import TcType ( isFFITy )
188 import HscTypes ( ModIface(..), TyThing(..), IfacePackage(..),
189 ModGuts(..), ModGuts, IfaceExport,
190 GhciMode(..), HscEnv(..), hscEPS,
191 Dependencies(..), FixItem(..),
192 mkIfaceDepCache, mkIfaceFixCache, mkIfaceVerCache,
194 GenAvailInfo(..), availName,
195 ExternalPackageState(..),
196 Usage(..), IsBootInterface,
197 Deprecs(..), IfaceDeprecs, Deprecations,
203 import Name ( Name, nameModule, nameOccName, nameParent,
204 isExternalName, nameParent_maybe, isWiredInName,
208 import OccName ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
210 OccSet, emptyOccSet, elemOccSet, occSetElts,
211 extendOccSet, extendOccSetList,
212 isEmptyOccSet, intersectOccSet, intersectsOccSet,
214 import TyCon ( tyConDataCons, isNewTyCon, newTyConRep )
215 import Class ( classSelIds )
216 import DataCon ( dataConName, dataConFieldLabels )
217 import Module ( Module, moduleFS,
218 ModLocation(..), mkSysModuleFS, moduleUserString,
219 ModuleEnv, emptyModuleEnv, lookupModuleEnv,
223 import DriverUtil ( createDirectoryHierarchy, directoryOf )
224 import Util ( sortLe, seqList )
225 import Binary ( getBinFileWithDict )
226 import BinIface ( writeBinIface, v_IgnoreHiWay )
227 import Unique ( Unique, Uniquable(..) )
228 import ErrUtils ( dumpIfSet_dyn, showPass )
229 import Digraph ( stronglyConnComp, SCC(..) )
230 import SrcLoc ( SrcSpan )
234 import DATA_IOREF ( writeIORef )
235 import Monad ( when )
236 import List ( insert )
237 import Maybes ( orElse, mapCatMaybes, isNothing, fromJust, expectJust )
242 %************************************************************************
244 \subsection{Completing an interface}
246 %************************************************************************
251 -> Maybe ModIface -- The old interface, if we have it
252 -> ModGuts -- The compiled, tidied module
253 -> IO ModIface -- The new one, complete with decls and versions
255 -- a) completes the interface
256 -- b) writes it out to a file if necessary
258 mkIface hsc_env location maybe_old_iface
259 guts@ModGuts{ mg_module = this_mod,
262 mg_exports = exports,
263 mg_fix_env = fix_env,
264 mg_deprecs = src_deprecs,
267 mg_types = type_env }
268 = do { eps <- hscEPS hsc_env
269 ; let { ext_nm = mkExtNameFn hsc_env eps this_mod
270 ; local_things = [thing | thing <- typeEnvElts type_env,
271 not (isWiredInName (getName thing)) ]
272 -- Do not export anything about wired-in things
273 -- (GHC knows about them already)
275 ; abstract_tcs :: NameSet -- TyCons and Classes whose representation is not exposed
277 | not omit_prags = emptyNameSet -- In the -O case, nothing is abstract
278 | otherwise = mkNameSet [ getName thing
279 | thing <- local_things
280 , not (mustExposeThing exports thing)]
282 ; decls = [ tyThingToIfaceDecl omit_prags abstract_tcs ext_nm thing
283 | thing <- local_things, wantDeclFor exports abstract_tcs thing ]
284 -- Don't put implicit Ids and class tycons in the interface file
286 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
287 ; deprecs = mkIfaceDeprec src_deprecs
290 | otherwise = sortLe le_rule $
291 map (coreRuleToIfaceRule this_mod ext_nm) rules
292 ; iface_insts = sortLe le_inst (map dfunToIfaceInst insts)
294 ; intermediate_iface = ModIface {
295 mi_module = this_mod,
296 mi_package = ThisPackage,
300 mi_exports = mkIfaceExports exports,
301 mi_insts = iface_insts,
302 mi_rules = iface_rules,
303 mi_fixities = fixities,
304 mi_deprecs = deprecs,
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_decls = deliberatelyOmitted "decls",
313 mi_ver_fn = deliberatelyOmitted "ver_fn",
315 -- And build the cached values
316 mi_dep_fn = mkIfaceDepCache deprecs,
317 mi_fix_fn = mkIfaceFixCache fixities }
319 -- Add version information
320 ; (new_iface, no_change_at_all, pp_diffs)
321 = _scc_ "versioninfo"
322 addVersionInfo maybe_old_iface intermediate_iface decls
325 -- Write the interface file, if necessary
326 ; when (not no_change_at_all && ghci_mode /= Interactive) $ do
327 createDirectoryHierarchy (directoryOf hi_file_path)
328 writeBinIface hi_file_path new_iface
331 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
332 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
333 (pprModIface new_iface)
337 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
338 i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
340 dflags = hsc_dflags hsc_env
341 ghci_mode = hsc_mode hsc_env
342 hi_file_path = ml_hi_file location
343 omit_prags = dopt Opt_OmitInterfacePragmas dflags
346 mustExposeThing :: NameSet -> TyThing -> Bool
347 -- We are compiling without -O, and thus trying to write as little as
348 -- possible into the interface file. But we must expose the details of
349 -- any data types and classes whose constructors, fields, methods are
350 -- visible to an importing module
351 mustExposeThing exports (ATyCon tc)
352 = any exported_data_con (tyConDataCons tc)
353 -- Expose rep if any datacon or field is exported
355 || (isNewTyCon tc && isFFITy (snd (newTyConRep tc)))
356 -- Expose the rep for newtypes if the rep is an FFI type.
357 -- For a very annoying reason. 'Foreign import' is meant to
358 -- be able to look through newtypes transparently, but it
359 -- can only do that if it can "see" the newtype representation
361 exported_data_con con
362 = any (`elemNameSet` exports) (dataConName con : dataConFieldLabels con)
364 mustExposeThing exports (AClass cls)
365 = any exported_class_op (classSelIds cls)
366 where -- Expose rep if any classs op is exported
367 exported_class_op op = getName op `elemNameSet` exports
369 mustExposeThing exports other = False
372 wantDeclFor :: NameSet -- User-exported things
373 -> NameSet -- Abstract things
375 wantDeclFor exports abstracts thing
376 | Just parent <- nameParent_maybe name -- An implicit thing
377 = parent `elemNameSet` abstracts && name `elemNameSet` exports
384 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
386 -----------------------------
387 mkExtNameFn :: HscEnv -> ExternalPackageState -> Module -> Name -> IfaceExtName
388 mkExtNameFn hsc_env eps this_mod
391 dflags = hsc_dflags hsc_env
392 hpt = hsc_HPT hsc_env
396 | mod == this_mod = case nameParent_maybe name of
397 Nothing -> LocalTop occ
398 Just par -> LocalTopSub occ (nameOccName par)
399 | isWiredInName name = ExtPkg mod occ
400 | isHomeModule dflags mod = HomePkg mod occ vers
401 | otherwise = ExtPkg mod occ
403 mod = nameModule name
404 occ = nameOccName name
405 par_occ = nameOccName (nameParent name)
406 -- The version of the *parent* is the one want
407 vers = lookupVersion mod par_occ
409 lookupVersion :: Module -> OccName -> Version
410 -- Even though we're looking up a home-package thing, in
411 -- one-shot mode the imported interfaces may be in the PIT
412 lookupVersion mod occ
413 = mi_ver_fn iface occ `orElse`
414 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
416 iface = lookupIfaceByModule hpt pit mod `orElse`
417 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
419 -----------------------------
420 -- Compute version numbers for local decls
422 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
423 -> ModIface -- The new interface decls (lacking decls)
424 -> [IfaceDecl] -- The new decls
426 Bool, -- True <=> no changes at all; no need to write new Iface
429 addVersionInfo Nothing new_iface new_decls
430 -- No old interface, so definitely write a new one!
431 = (new_iface { mi_orphan = anyNothing getInstKey (mi_insts new_iface)
432 || anyNothing getRuleKey (mi_rules new_iface),
433 mi_decls = [(initialVersion, decl) | decl <- new_decls],
434 mi_ver_fn = \n -> Just initialVersion },
435 False, ptext SLIT("No old interface file") $$
436 pprOrphans orph_insts orph_rules)
438 orph_insts = filter (isNothing . getInstKey) (mi_insts new_iface)
439 orph_rules = filter (isNothing . getRuleKey) (mi_rules new_iface)
441 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
442 mi_exp_vers = old_exp_vers,
443 mi_rule_vers = old_rule_vers,
444 mi_decls = old_decls,
445 mi_ver_fn = old_decl_vers,
446 mi_fix_fn = old_fixities }))
447 new_iface@(ModIface { mi_fix_fn = new_fixities })
450 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged") $$ pp_orphs)
451 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
453 text "" $$ pp_orphs])
455 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
456 mi_exp_vers = bump_unless no_export_change old_exp_vers,
457 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
458 mi_orphan = not (null new_orph_rules && null new_orph_insts),
459 mi_decls = decls_w_vers,
460 mi_ver_fn = mkIfaceVerCache decls_w_vers }
462 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
465 (old_non_orph_insts, old_orph_insts) = mkRuleMap getInstKey (mi_insts old_iface)
466 (new_non_orph_insts, new_orph_insts) = mkRuleMap getInstKey (mi_insts new_iface)
467 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
468 (lookupOccEnv old_non_orph_insts occ)
469 (lookupOccEnv new_non_orph_insts occ)
471 (old_non_orph_rules, old_orph_rules) = mkRuleMap getRuleKey (mi_rules old_iface)
472 (new_non_orph_rules, new_orph_rules) = mkRuleMap getRuleKey (mi_rules new_iface)
473 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
474 (lookupOccEnv old_non_orph_rules occ)
475 (lookupOccEnv new_non_orph_rules occ)
477 -- Computing what changed
478 no_output_change = no_decl_change && no_rule_change &&
479 no_export_change && no_deprec_change
480 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
481 no_decl_change = isEmptyOccSet changed_occs
482 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
483 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
484 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
486 -- If the usages havn't changed either, we don't need to write the interface file
487 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
488 mi_deps new_iface == mi_deps old_iface
489 no_change_at_all = no_output_change && no_other_changes
491 pp_diffs = vcat [pp_change no_export_change "Export list"
492 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
493 pp_change no_rule_change "Rules"
494 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
495 pp_change no_deprec_change "Deprecations" empty,
496 pp_change no_other_changes "Usages" empty,
498 pp_change True what info = empty
499 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
502 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
503 same_fixity n = bool (old_fixities n == new_fixities n)
506 -- Adding version info
507 new_version = bumpVersion old_mod_vers
508 add_vers decl | occ `elemOccSet` changed_occs = new_version
509 | otherwise = expectJust "add_vers" (old_decl_vers occ)
510 -- If it's unchanged, there jolly well
511 where -- should be an old version number
515 changed_occs :: OccSet
516 changed_occs = computeChangedOccs eq_info
518 eq_info :: [(OccName, IfaceEq)]
519 eq_info = map check_eq new_decls
520 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
521 = (occ, new_decl `eqIfDecl` old_decl &&&
522 eq_indirects new_decl)
523 | otherwise {- No corresponding old decl -}
526 occ = ifName new_decl
528 eq_indirects :: IfaceDecl -> IfaceEq
529 -- When seeing if two decls are the same, remember to
530 -- check whether any relevant fixity or rules have changed
531 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
532 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
533 = same_insts cls_occ &&&
534 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
535 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
536 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
537 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
538 eq_indirects other = Equal -- Synonyms and foreign declarations
540 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
541 eq_ind_occ occ = same_fixity occ &&& same_rules occ
542 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
546 pp_decl_diffs :: SDoc -- Nothing => no changes
548 | isEmptyOccSet changed_occs = empty
550 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
551 ptext SLIT("Version change for these decls:"),
552 nest 2 (vcat (map show_change new_decls))]
554 eq_env = mkOccEnv eq_info
556 | not (occ `elemOccSet` changed_occs) = empty
558 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
561 occ = ifName new_decl
562 why = case lookupOccEnv eq_env occ of
563 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
564 nest 2 (braces (fsep (map ppr (occSetElts
565 (occs `intersectOccSet` changed_occs)))))]
567 | Just old_decl <- lookupOccEnv old_decl_env occ
568 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
569 ptext SLIT("New:") <+> ppr new_decl]
571 -> ppr occ <+> ptext SLIT("only in new interface")
572 other -> pprPanic "MkIface.show_change" (ppr occ)
574 pp_orphs = pprOrphans new_orph_insts new_orph_rules
576 pprOrphans insts rules
577 = vcat [if null insts then empty else
578 ptext SLIT("Orphan instances:") <+> vcat (map ppr insts),
579 if null rules then empty else
580 ptext SLIT("Orphan rules:") <+> vcat (map ppr rules)]
582 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
583 computeChangedOccs eq_info
584 = foldl add_changes emptyOccSet (stronglyConnComp edges)
586 edges :: [((OccName,IfaceEq), Unique, [Unique])]
587 edges = [ (node, getUnique occ, map getUnique occs)
588 | node@(occ, iface_eq) <- eq_info
589 , let occs = case iface_eq of
590 EqBut occ_set -> occSetElts occ_set
593 -- Changes in declarations
594 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
595 add_changes so_far (AcyclicSCC (occ, iface_eq))
596 | changedWrt so_far iface_eq -- This one has changed
597 = extendOccSet so_far occ
598 add_changes so_far (CyclicSCC pairs)
599 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
600 = extendOccSetList so_far (map fst pairs)
601 add_changes so_far other = so_far
603 changedWrt :: OccSet -> IfaceEq -> Bool
604 changedWrt so_far Equal = False
605 changedWrt so_far NotEqual = True
606 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
608 ----------------------
609 -- mkRuleMap partitions instance decls or rules into
610 -- (a) an OccEnv for ones that are not orphans,
611 -- mapping the local OccName to a list of its decls
612 -- (b) a list of orphan decls
613 mkRuleMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
614 -- Nothing for an orphan decl
615 -> [decl] -- Sorted into canonical order
616 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
617 -- each sublist in canonical order
618 [decl]) -- Orphan decls; in canonical order
619 mkRuleMap get_key decls
620 = foldl go (emptyOccEnv, []) decls
622 go (non_orphs, orphs) d
623 | Just occ <- get_key d
624 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
625 | otherwise = (non_orphs, d:orphs)
627 -- getXxKey: find at least one local OccName that belongs to this decl
629 getInstKey :: IfaceInst -> Maybe OccName
630 getInstKey (IfaceInst {ifInstHead = inst_ty})
631 = case [occ | LocalTop occ <- cls_ext : tc_exts] of
635 (cls_ext, tcs) = ifaceInstGates inst_ty
636 tc_exts = [tc | IfaceTc tc <- tcs]
637 -- Ignore the wired-in IfaceTyCons; the class will do as the key
639 getRuleKey :: IfaceRule -> Maybe OccName
640 getRuleKey (IfaceRule {ifRuleHead = LocalTop occ}) = Just occ
641 getRuleKey other = Nothing
643 anyNothing :: (a -> Maybe b) -> [a] -> Bool
644 anyNothing p [] = False
645 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
647 ----------------------
648 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
649 mkIfaceDeprec NoDeprecs = NoDeprecs
650 mkIfaceDeprec (DeprecAll t) = DeprecAll t
651 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
653 ----------------------
654 bump_unless :: Bool -> Version -> Version
655 bump_unless True v = v -- True <=> no change
656 bump_unless False v = bumpVersion v
660 %*********************************************************
662 \subsection{Keeping track of what we've slurped, and version numbers}
664 %*********************************************************
668 mkUsageInfo :: HscEnv
669 -> ModuleEnv (Module, Maybe Bool, SrcSpan)
670 -> [(Module, IsBootInterface)]
671 -> NameSet -> IO [Usage]
672 mkUsageInfo hsc_env dir_imp_mods dep_mods used_names
673 = do { eps <- hscEPS hsc_env
674 ; let usages = mk_usage_info (eps_PIT eps) hsc_env
675 dir_imp_mods dep_mods used_names
676 ; usages `seqList` return usages }
677 -- seq the list of Usages returned: occasionally these
678 -- don't get evaluated for a while and we can end up hanging on to
679 -- the entire collection of Ifaces.
681 mk_usage_info pit hsc_env dir_imp_mods dep_mods proto_used_names
682 = mapCatMaybes mkUsage dep_mods
683 -- ToDo: do we need to sort into canonical order?
685 dflags = hsc_dflags hsc_env
686 hpt = hsc_HPT hsc_env
688 used_names = mkNameSet $ -- Eliminate duplicates
689 [ nameParent n -- Just record usage on the 'main' names
690 | n <- nameSetToList proto_used_names
691 , not (isWiredInName n) -- Don't record usages for wired-in names
692 , isExternalName n -- Ignore internal names
695 -- ent_map groups together all the things imported and used
696 -- from a particular module in this package
697 ent_map :: ModuleEnv [OccName]
698 ent_map = foldNameSet add_mv emptyModuleEnv used_names
699 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
701 occ = nameOccName name
702 mod = nameModule name
703 add_item occs _ = occ:occs
705 import_all mod = case lookupModuleEnv dir_imp_mods mod of
706 Just (_,imp_all,_) -> isNothing imp_all
709 -- We want to create a Usage for a home module if
710 -- a) we used something from; has something in used_names
711 -- b) we imported all of it, even if we used nothing from it
712 -- (need to recompile if its export list changes: export_vers)
713 -- c) is a home-package orphan module (need to recompile if its
714 -- instance decls change: rules_vers)
715 mkUsage :: (Module, Bool) -> Maybe Usage
716 mkUsage (mod_name, _)
717 | isNothing maybe_iface -- We can't depend on it if we didn't
718 || not (isHomeModule dflags mod) -- even open the interface!
722 = Nothing -- Record no usage info
725 = Just (Usage { usg_name = mod,
727 usg_exports = export_vers,
728 usg_entities = ent_vers,
729 usg_rules = rules_vers })
731 maybe_iface = lookupIfaceByModule hpt pit mod_name
732 -- In one-shot mode, the interfaces for home-package
733 -- modules accumulate in the PIT not HPT. Sigh.
735 Just iface = maybe_iface
736 mod = mi_module iface
737 orphan_mod = mi_orphan iface
738 version_env = mi_ver_fn iface
739 mod_vers = mi_mod_vers iface
740 rules_vers = mi_rule_vers iface
741 all_imported = import_all mod
742 export_vers | all_imported = Just (mi_exp_vers iface)
743 | otherwise = Nothing
745 -- The sort is to put them into canonical order
746 used_occs = lookupModuleEnv ent_map mod `orElse` []
747 ent_vers :: [(OccName,Version)]
748 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
749 | occ <- sortLe (<=) used_occs]
753 mkIfaceExports :: NameSet -> [(Module, [GenAvailInfo OccName])]
754 -- Group by module and sort by occurrence
755 -- This keeps the list in canonical order
756 mkIfaceExports exports
757 = [ (mkSysModuleFS fs, eltsFM avails)
758 | (fs, avails) <- fmToList groupFM
761 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
762 -- Deliberately use the FastString so we
763 -- get a canonical ordering
764 groupFM = foldl add emptyFM (nameSetToList exports)
766 add env name = addToFM_C add_avail env mod_fs
767 (unitFM avail_fs avail)
769 occ = nameOccName name
770 mod_fs = moduleFS (nameModule name)
771 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
772 | isTcOcc occ = AvailTC occ [occ]
773 | otherwise = Avail occ
774 avail_fs = occNameFS (availName avail)
775 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
777 add_item (AvailTC p occs) _ = AvailTC p (insert occ occs)
778 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
782 %************************************************************************
784 Load the old interface file for this module (unless
785 we have it aleady), and check whether it is up to date
788 %************************************************************************
791 checkOldIface :: HscEnv
793 -> FilePath -- Where the interface file is
794 -> Bool -- Source unchanged
795 -> Maybe ModIface -- Old interface from compilation manager, if any
796 -> IO (RecompileRequired, Maybe ModIface)
798 checkOldIface hsc_env mod iface_path source_unchanged maybe_iface
799 = do { showPass (hsc_dflags hsc_env)
800 ("Checking old interface for " ++ moduleUserString mod) ;
802 ; initIfaceCheck hsc_env $
803 check_old_iface mod iface_path source_unchanged maybe_iface
806 check_old_iface this_mod iface_path source_unchanged maybe_iface
807 = -- CHECK WHETHER THE SOURCE HAS CHANGED
808 ifM (not source_unchanged)
809 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
812 -- If the source has changed and we're in interactive mode, avoid reading
813 -- an interface; just return the one we might have been supplied with.
814 getGhciMode `thenM` \ ghci_mode ->
815 if (ghci_mode == Interactive) && not source_unchanged then
816 returnM (outOfDate, maybe_iface)
819 case maybe_iface of {
820 Just old_iface -> -- Use the one we already have
821 checkVersions source_unchanged old_iface `thenM` \ recomp ->
822 returnM (recomp, Just old_iface)
826 -- Try and read the old interface for the current module
827 -- from the .hi file left from the last time we compiled it
828 readIface this_mod iface_path False `thenM` \ read_result ->
829 case read_result of {
830 Left err -> -- Old interface file not found, or garbled; give up
831 traceIf (text "FYI: cannot read old interface file:"
832 $$ nest 4 err) `thenM_`
833 returnM (outOfDate, Nothing)
837 -- We have got the old iface; check its versions
838 checkVersions source_unchanged iface `thenM` \ recomp ->
839 returnM (recomp, Just iface)
843 @recompileRequired@ is called from the HscMain. It checks whether
844 a recompilation is required. It needs access to the persistent state,
845 finder, etc, because it may have to load lots of interface files to
846 check their versions.
849 type RecompileRequired = Bool
850 upToDate = False -- Recompile not required
851 outOfDate = True -- Recompile required
853 checkVersions :: Bool -- True <=> source unchanged
854 -> ModIface -- Old interface
855 -> IfG RecompileRequired
856 checkVersions source_unchanged iface
857 | not source_unchanged
860 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
861 ppr (mi_module iface) <> colon)
863 -- Source code unchanged and no errors yet... carry on
865 -- First put the dependent-module info, read from the old interface, into the envt,
866 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
868 -- It's just temporary because either the usage check will succeed
869 -- (in which case we are done with this module) or it'll fail (in which
870 -- case we'll compile the module from scratch anyhow).
872 -- We do this regardless of compilation mode
873 ; updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
875 ; checkList [checkModUsage u | u <- mi_usages iface]
878 -- This is a bit of a hack really
879 mod_deps :: ModuleEnv (Module, IsBootInterface)
880 mod_deps = mkModDeps (dep_mods (mi_deps iface))
882 checkModUsage :: Usage -> IfG RecompileRequired
883 -- Given the usage information extracted from the old
884 -- M.hi file for the module being compiled, figure out
885 -- whether M needs to be recompiled.
887 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
888 usg_rules = old_rule_vers,
889 usg_exports = maybe_old_export_vers,
890 usg_entities = old_decl_vers })
891 = -- Load the imported interface is possible
893 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
895 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
897 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
898 -- Load the interface, but don't complain on failure;
899 -- Instead, get an Either back which we can test
902 Left exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
904 -- Couldn't find or parse a module mentioned in the
905 -- old interface file. Don't complain -- it might just be that
906 -- the current module doesn't need that import and it's been deleted
910 new_mod_vers = mi_mod_vers iface
911 new_decl_vers = mi_ver_fn iface
912 new_export_vers = mi_exp_vers iface
913 new_rule_vers = mi_rule_vers iface
916 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
917 if not recompile then
922 if checkExportList maybe_old_export_vers new_export_vers then
923 out_of_date_vers (ptext SLIT(" Export list changed"))
924 (fromJust maybe_old_export_vers)
929 if old_rule_vers /= new_rule_vers then
930 out_of_date_vers (ptext SLIT(" Rules changed"))
931 old_rule_vers new_rule_vers
934 -- CHECK ITEMS ONE BY ONE
935 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
937 returnM outOfDate -- This one failed, so just bail out now
939 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
942 ------------------------
943 checkModuleVersion old_mod_vers new_mod_vers
944 | new_mod_vers == old_mod_vers
945 = up_to_date (ptext SLIT("Module version unchanged"))
948 = out_of_date_vers (ptext SLIT(" Module version has changed"))
949 old_mod_vers new_mod_vers
951 ------------------------
952 checkExportList Nothing new_vers = upToDate
953 checkExportList (Just v) new_vers = v /= new_vers
955 ------------------------
956 checkEntityUsage new_vers (name,old_vers)
957 = case new_vers name of
959 Nothing -> -- We used it before, but it ain't there now
960 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
962 Just new_vers -- It's there, but is it up to date?
963 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
965 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
968 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
969 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
970 out_of_date_vers msg old_vers new_vers
971 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
973 ----------------------
974 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
975 -- This helper is used in two places
976 checkList [] = returnM upToDate
977 checkList (check:checks) = check `thenM` \ recompile ->
984 %************************************************************************
988 %************************************************************************
991 showIface :: FilePath -> IO ()
992 -- Raad binary interface, and print it out
993 showIface filename = do
994 -- skip the version check; we don't want to worry about profiled vs.
995 -- non-profiled interfaces, for example.
996 writeIORef v_IgnoreHiWay True
997 iface <- Binary.getBinFileWithDict filename
998 printDump (pprModIface iface)
1004 pprModIface :: ModIface -> SDoc
1007 = vcat [ ptext SLIT("interface")
1008 <+> ppr_package (mi_package iface)
1009 <+> ppr (mi_module iface) <+> ppr (mi_mod_vers iface)
1011 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
1012 <+> int opt_HiVersion
1013 <+> ptext SLIT("where")
1014 , vcat (map pprExport (mi_exports iface))
1015 , pprDeps (mi_deps iface)
1016 , vcat (map pprUsage (mi_usages iface))
1017 , pprFixities (mi_fixities iface)
1018 , vcat (map pprIfaceDecl (mi_decls iface))
1019 , vcat (map ppr (mi_insts iface))
1020 , vcat (map ppr (mi_rules iface))
1021 , pprDeprecs (mi_deprecs iface)
1024 ppr_package ThisPackage = empty
1025 ppr_package (ExternalPackage id) = doubleQuotes (ftext id)
1027 exp_vers = mi_exp_vers iface
1028 rule_vers = mi_rule_vers iface
1030 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1031 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1034 When printing export lists, we print like this:
1036 AvailTC C [C, x, y] C(x,y)
1037 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1040 pprExport :: IfaceExport -> SDoc
1041 pprExport (mod, items)
1042 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1044 pp_avail :: GenAvailInfo OccName -> SDoc
1045 pp_avail (Avail occ) = ppr occ
1046 pp_avail (AvailTC _ []) = empty
1047 pp_avail (AvailTC n (n':ns))
1048 | n==n' = ppr n <> pp_export ns
1049 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1051 pp_export [] = empty
1052 pp_export names = braces (hsep (map ppr names))
1054 pprUsage :: Usage -> SDoc
1056 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1057 int (usg_mod usage),
1058 pp_export_version (usg_exports usage),
1059 int (usg_rules usage),
1060 pp_versions (usg_entities usage) ]
1062 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1063 pp_export_version Nothing = empty
1064 pp_export_version (Just v) = int v
1066 pprDeps :: Dependencies -> SDoc
1067 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1068 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1069 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1070 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1073 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1074 ppr_boot True = text "[boot]"
1075 ppr_boot False = empty
1077 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1078 pprIfaceDecl (ver, decl)
1079 = ppr_vers ver <+> ppr decl
1081 -- Print the version for the decl
1082 ppr_vers v | v == initialVersion = empty
1085 pprFixities :: [(OccName, Fixity)] -> SDoc
1086 pprFixities [] = empty
1087 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1089 pprFix (occ,fix) = ppr fix <+> ppr occ
1091 pprDeprecs NoDeprecs = empty
1092 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1093 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1095 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)