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,
180 eqMaybeBy, eqListBy, visibleIfConDecls,
181 tyThingToIfaceDecl, dfunToIfaceInst, coreRuleToIfaceRule )
182 import LoadIface ( readIface, loadInterface, ifaceInstGates )
183 import BasicTypes ( Version, initialVersion, bumpVersion )
185 import TcRnTypes ( ImportAvails(..), mkModDeps )
186 import TcType ( isFFITy )
187 import HscTypes ( ModIface(..), TyThing(..),
188 ModGuts(..), ModGuts, IfaceExport,
189 GhciMode(..), isOneShot,
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, isExternalName,
204 nameParent_maybe, isWiredInName, NamedThing(..), nameModuleName )
207 import OccName ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv_C,
208 OccSet, emptyOccSet, elemOccSet, occSetElts,
209 extendOccSet, extendOccSetList,
210 isEmptyOccSet, intersectOccSet, intersectsOccSet,
212 import TyCon ( tyConDataCons, isNewTyCon, newTyConRep )
213 import Class ( classSelIds )
214 import DataCon ( dataConName, dataConFieldLabels )
215 import Module ( Module, ModuleName, moduleNameFS, moduleName, isHomeModule,
216 ModLocation(..), mkSysModuleNameFS, moduleUserString,
217 ModuleEnv, emptyModuleEnv, lookupModuleEnv,
218 extendModuleEnv_C, moduleEnvElts
221 import DriverUtil ( createDirectoryHierarchy, directoryOf )
222 import Util ( sortLe, seqList )
223 import Binary ( getBinFileWithDict )
224 import BinIface ( writeBinIface, v_IgnoreHiWay )
225 import Unique ( Unique, Uniquable(..) )
226 import ErrUtils ( dumpIfSet_dyn, showPass )
227 import Digraph ( stronglyConnComp, SCC(..) )
231 import DATA_IOREF ( writeIORef )
232 import Monad ( when )
233 import List ( insert )
234 import Maybes ( orElse, mapCatMaybes, isNothing, fromJust, expectJust )
239 %************************************************************************
241 \subsection{Completing an interface}
243 %************************************************************************
248 -> Maybe ModIface -- The old interface, if we have it
249 -> ModGuts -- The compiled, tidied module
250 -> IO ModIface -- The new one, complete with decls and versions
252 -- a) completes the interface
253 -- b) writes it out to a file if necessary
255 mkIface hsc_env location maybe_old_iface
256 guts@ModGuts{ mg_module = this_mod,
259 mg_exports = exports,
260 mg_fix_env = fix_env,
261 mg_deprecs = src_deprecs,
264 mg_types = type_env }
265 = do { eps <- hscEPS hsc_env
266 ; let { this_mod_name = moduleName this_mod
267 ; ext_nm = mkExtNameFn hsc_env eps this_mod_name
268 ; local_things = [thing | thing <- typeEnvElts type_env,
269 not (isWiredInName (getName thing)) ]
270 -- Do not export anything about wired-in things
271 -- (GHC knows about them already)
273 ; abstract_tcs :: NameSet -- TyCons and Classes whose representation is not exposed
275 | not omit_prags = emptyNameSet -- In the -O case, nothing is abstract
276 | otherwise = mkNameSet [ getName thing
277 | thing <- local_things
278 , not (mustExposeThing exports thing)]
280 ; decls = [ tyThingToIfaceDecl omit_prags abstract_tcs ext_nm thing
281 | thing <- local_things, wantDeclFor exports abstract_tcs thing ]
282 -- Don't put implicit Ids and class tycons in the interface file
284 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
285 ; deprecs = mkIfaceDeprec src_deprecs
288 | otherwise = sortLe le_rule $
289 map (coreRuleToIfaceRule this_mod_name ext_nm) rules
290 ; iface_insts = sortLe le_inst (map dfunToIfaceInst insts)
292 ; intermediate_iface = ModIface {
293 mi_module = this_mod,
294 mi_package = opt_InPackage,
298 mi_exports = mkIfaceExports exports,
299 mi_insts = iface_insts,
300 mi_rules = iface_rules,
301 mi_fixities = fixities,
302 mi_deprecs = deprecs,
304 -- Left out deliberately: filled in by addVersionInfo
305 mi_mod_vers = initialVersion,
306 mi_exp_vers = initialVersion,
307 mi_rule_vers = initialVersion,
308 mi_orphan = False, -- Always set by addVersionInfo, but
309 -- it's a strict field, so we can't omit it.
310 mi_decls = deliberatelyOmitted "decls",
311 mi_ver_fn = deliberatelyOmitted "ver_fn",
313 -- And build the cached values
314 mi_dep_fn = mkIfaceDepCache deprecs,
315 mi_fix_fn = mkIfaceFixCache fixities }
317 -- Add version information
318 ; (new_iface, no_change_at_all, pp_diffs)
319 = _scc_ "versioninfo"
320 addVersionInfo maybe_old_iface intermediate_iface decls
323 -- Write the interface file, if necessary
324 ; when (not no_change_at_all && ghci_mode /= Interactive) $ do
325 createDirectoryHierarchy (directoryOf hi_file_path)
326 writeBinIface hi_file_path new_iface
329 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
330 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
331 (pprModIface new_iface)
335 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
336 i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
338 dflags = hsc_dflags hsc_env
339 ghci_mode = hsc_mode hsc_env
340 hi_file_path = ml_hi_file location
341 omit_prags = dopt Opt_OmitInterfacePragmas dflags
344 mustExposeThing :: NameSet -> TyThing -> Bool
345 -- We are compiling without -O, and thus trying to write as little as
346 -- possible into the interface file. But we must expose the details of
347 -- any data types and classes whose constructors, fields, methods are
348 -- visible to an importing module
349 mustExposeThing exports (ATyCon tc)
350 = any exported_data_con (tyConDataCons tc)
351 -- Expose rep if any datacon or field is exported
353 || (isNewTyCon tc && isFFITy (snd (newTyConRep tc)))
354 -- Expose the rep for newtypes if the rep is an FFI type.
355 -- For a very annoying reason. 'Foreign import' is meant to
356 -- be able to look through newtypes transparently, but it
357 -- can only do that if it can "see" the newtype representation
359 exported_data_con con
360 = any (`elemNameSet` exports) (dataConName con : dataConFieldLabels con)
362 mustExposeThing exports (AClass cls)
363 = any exported_class_op (classSelIds cls)
364 where -- Expose rep if any classs op is exported
365 exported_class_op op = getName op `elemNameSet` exports
367 mustExposeThing exports other = False
370 wantDeclFor :: NameSet -- User-exported things
371 -> NameSet -- Abstract things
373 wantDeclFor exports abstracts thing
374 | Just parent <- nameParent_maybe name -- An implicit thing
375 = parent `elemNameSet` abstracts && name `elemNameSet` exports
382 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
384 -----------------------------
385 mkExtNameFn :: HscEnv -> ExternalPackageState -> ModuleName -> Name -> IfaceExtName
386 mkExtNameFn hsc_env eps this_mod
389 hpt = hsc_HPT hsc_env
393 | mod_nm == this_mod = case nameParent_maybe name of
394 Nothing -> LocalTop occ
395 Just par -> LocalTopSub occ (nameOccName par)
396 | isWiredInName name = ExtPkg mod_nm occ
397 | isHomeModule mod = HomePkg mod_nm occ vers
398 | otherwise = ExtPkg mod_nm occ
400 mod = nameModule name
401 mod_nm = moduleName mod
402 occ = nameOccName name
403 par_occ = nameOccName (nameParent name)
404 -- The version of the *parent* is the one want
405 vers = lookupVersion mod_nm par_occ
407 lookupVersion :: ModuleName -> OccName -> Version
408 -- Even though we're looking up a home-package thing, in
409 -- one-shot mode the imported interfaces may be in the PIT
410 lookupVersion mod occ
411 = mi_ver_fn iface occ `orElse`
412 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
414 iface = lookupIfaceByModName hpt pit mod `orElse`
415 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
417 -----------------------------
418 -- Compute version numbers for local decls
420 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
421 -> ModIface -- The new interface decls (lacking decls)
422 -> [IfaceDecl] -- The new decls
424 Bool, -- True <=> no changes at all; no need to write new Iface
427 addVersionInfo Nothing new_iface new_decls
428 -- No old interface, so definitely write a new one!
429 = (new_iface { mi_orphan = anyNothing getInstKey (mi_insts new_iface)
430 || anyNothing getRuleKey (mi_rules new_iface),
431 mi_decls = [(initialVersion, decl) | decl <- new_decls],
432 mi_ver_fn = \n -> Just initialVersion },
433 False, ptext SLIT("No old interface file") $$
434 pprOrphans orph_insts orph_rules)
436 orph_insts = filter (isNothing . getInstKey) (mi_insts new_iface)
437 orph_rules = filter (isNothing . getRuleKey) (mi_rules new_iface)
439 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
440 mi_exp_vers = old_exp_vers,
441 mi_rule_vers = old_rule_vers,
442 mi_decls = old_decls,
443 mi_ver_fn = old_decl_vers,
444 mi_fix_fn = old_fixities }))
445 new_iface@(ModIface { mi_fix_fn = new_fixities })
448 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged") $$ pp_orphs)
449 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
451 text "" $$ pp_orphs])
453 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
454 mi_exp_vers = bump_unless no_export_change old_exp_vers,
455 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
456 mi_orphan = not (null new_orph_rules && null new_orph_insts),
457 mi_decls = decls_w_vers,
458 mi_ver_fn = mkIfaceVerCache decls_w_vers }
460 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
463 (old_non_orph_insts, old_orph_insts) = mkRuleMap getInstKey (mi_insts old_iface)
464 (new_non_orph_insts, new_orph_insts) = mkRuleMap getInstKey (mi_insts new_iface)
465 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
466 (lookupOccEnv old_non_orph_insts occ)
467 (lookupOccEnv new_non_orph_insts occ)
469 (old_non_orph_rules, old_orph_rules) = mkRuleMap getRuleKey (mi_rules old_iface)
470 (new_non_orph_rules, new_orph_rules) = mkRuleMap getRuleKey (mi_rules new_iface)
471 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
472 (lookupOccEnv old_non_orph_rules occ)
473 (lookupOccEnv new_non_orph_rules occ)
475 -- Computing what changed
476 no_output_change = no_decl_change && no_rule_change &&
477 no_export_change && no_deprec_change
478 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
479 no_decl_change = isEmptyOccSet changed_occs
480 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
481 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
482 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
484 -- If the usages havn't changed either, we don't need to write the interface file
485 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
486 mi_deps new_iface == mi_deps old_iface
487 no_change_at_all = no_output_change && no_other_changes
489 pp_diffs = vcat [pp_change no_export_change "Export list"
490 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
491 pp_change no_rule_change "Rules"
492 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
493 pp_change no_deprec_change "Deprecations" empty,
494 pp_change no_other_changes "Usages" empty,
496 pp_change True what info = empty
497 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
500 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
501 same_fixity n = bool (old_fixities n == new_fixities n)
504 -- Adding version info
505 new_version = bumpVersion old_mod_vers
506 add_vers decl | occ `elemOccSet` changed_occs = new_version
507 | otherwise = expectJust "add_vers" (old_decl_vers occ)
508 -- If it's unchanged, there jolly well
509 where -- should be an old version number
513 changed_occs :: OccSet
514 changed_occs = computeChangedOccs eq_info
516 eq_info :: [(OccName, IfaceEq)]
517 eq_info = map check_eq new_decls
518 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
519 = (occ, new_decl `eqIfDecl` old_decl &&&
520 eq_indirects new_decl)
521 | otherwise {- No corresponding old decl -}
524 occ = ifName new_decl
526 eq_indirects :: IfaceDecl -> IfaceEq
527 -- When seeing if two decls are the same, remember to
528 -- check whether any relevant fixity or rules have changed
529 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
530 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
531 = same_insts cls_occ &&&
532 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
533 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
534 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
535 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
536 eq_indirects other = Equal -- Synonyms and foreign declarations
538 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
539 eq_ind_occ occ = same_fixity occ &&& same_rules occ
540 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
544 pp_decl_diffs :: SDoc -- Nothing => no changes
546 | isEmptyOccSet changed_occs = empty
548 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
549 ptext SLIT("Version change for these decls:"),
550 nest 2 (vcat (map show_change new_decls))]
552 eq_env = mkOccEnv eq_info
554 | not (occ `elemOccSet` changed_occs) = empty
556 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
559 occ = ifName new_decl
560 why = case lookupOccEnv eq_env occ of
561 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
562 nest 2 (braces (fsep (map ppr (occSetElts
563 (occs `intersectOccSet` changed_occs)))))]
565 | Just old_decl <- lookupOccEnv old_decl_env occ
566 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
567 ptext SLIT("New:") <+> ppr new_decl]
569 -> ppr occ <+> ptext SLIT("only in new interface")
570 other -> pprPanic "MkIface.show_change" (ppr occ)
572 pp_orphs = pprOrphans new_orph_insts new_orph_rules
574 pprOrphans insts rules
575 = vcat [if null insts then empty else
576 ptext SLIT("Orphan instances:") <+> vcat (map ppr insts),
577 if null rules then empty else
578 ptext SLIT("Orphan rules:") <+> vcat (map ppr rules)]
580 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
581 computeChangedOccs eq_info
582 = foldl add_changes emptyOccSet (stronglyConnComp edges)
584 edges :: [((OccName,IfaceEq), Unique, [Unique])]
585 edges = [ (node, getUnique occ, map getUnique occs)
586 | node@(occ, iface_eq) <- eq_info
587 , let occs = case iface_eq of
588 EqBut occ_set -> occSetElts occ_set
591 -- Changes in declarations
592 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
593 add_changes so_far (AcyclicSCC (occ, iface_eq))
594 | changedWrt so_far iface_eq -- This one has changed
595 = extendOccSet so_far occ
596 add_changes so_far (CyclicSCC pairs)
597 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
598 = extendOccSetList so_far (map fst pairs)
599 add_changes so_far other = so_far
601 changedWrt :: OccSet -> IfaceEq -> Bool
602 changedWrt so_far Equal = False
603 changedWrt so_far NotEqual = True
604 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
606 ----------------------
607 -- mkRuleMap partitions instance decls or rules into
608 -- (a) an OccEnv for ones that are not orphans,
609 -- mapping the local OccName to a list of its decls
610 -- (b) a list of orphan decls
611 mkRuleMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
612 -- Nothing for an orphan decl
613 -> [decl] -- Sorted into canonical order
614 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
615 -- each sublist in canonical order
616 [decl]) -- Orphan decls; in canonical order
617 mkRuleMap get_key decls
618 = foldl go (emptyOccEnv, []) decls
620 go (non_orphs, orphs) d
621 | Just occ <- get_key d
622 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
623 | otherwise = (non_orphs, d:orphs)
625 -- getXxKey: find at least one local OccName that belongs to this decl
627 getInstKey :: IfaceInst -> Maybe OccName
628 getInstKey (IfaceInst {ifInstHead = inst_ty})
629 = case [occ | LocalTop occ <- cls_ext : tc_exts] of
633 (cls_ext, tcs) = ifaceInstGates inst_ty
634 tc_exts = [tc | IfaceTc tc <- tcs]
635 -- Ignore the wired-in IfaceTyCons; the class will do as the key
637 getRuleKey :: IfaceRule -> Maybe OccName
638 getRuleKey (IfaceRule {ifRuleHead = LocalTop occ}) = Just occ
639 getRuleKey other = Nothing
641 anyNothing :: (a -> Maybe b) -> [a] -> Bool
642 anyNothing p [] = False
643 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
645 ----------------------
646 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
647 mkIfaceDeprec NoDeprecs = NoDeprecs
648 mkIfaceDeprec (DeprecAll t) = DeprecAll t
649 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
651 ----------------------
652 bump_unless :: Bool -> Version -> Version
653 bump_unless True v = v -- True <=> no change
654 bump_unless False v = bumpVersion v
658 %*********************************************************
660 \subsection{Keeping track of what we've slurped, and version numbers}
662 %*********************************************************
666 mkUsageInfo :: HscEnv -> ImportAvails -> NameSet -> IO [Usage]
668 (ImportAvails { imp_mods = dir_imp_mods,
669 imp_dep_mods = dep_mods })
671 = do { eps <- hscEPS hsc_env
672 ; return (mk_usage_info (eps_PIT eps) (hsc_HPT hsc_env)
673 dir_imp_mods dep_mods used_names) }
675 mk_usage_info pit hpt dir_imp_mods dep_mods proto_used_names
676 = -- seq the list of Usages returned: occasionally these
677 -- don't get evaluated for a while and we can end up hanging on to
678 -- the entire collection of Ifaces.
679 usages `seqList` usages
681 used_names = mkNameSet $ -- Eliminate duplicates
682 [ nameParent n -- Just record usage on the 'main' names
683 | n <- nameSetToList proto_used_names
684 , not (isWiredInName n) -- Don't record usages for wired-in names
685 , isExternalName n -- Ignore internal names
688 -- ent_map groups together all the things imported and used
689 -- from a particular module in this package
690 ent_map :: ModuleEnv [OccName]
691 ent_map = foldNameSet add_mv emptyModuleEnv used_names
692 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
694 occ = nameOccName name
695 mod = nameModule name
696 add_item occs _ = occ:occs
698 usages = mapCatMaybes mkUsage (moduleEnvElts dep_mods)
699 -- ToDo: do we need to sort into canonical order?
701 import_all mod = case lookupModuleEnv dir_imp_mods mod of
702 Just (_,imp_all,_) -> isNothing imp_all
705 -- We want to create a Usage for a home module if
706 -- a) we used something from; has something in used_names
707 -- b) we imported all of it, even if we used nothing from it
708 -- (need to recompile if its export list changes: export_vers)
709 -- c) is a home-package orphan module (need to recompile if its
710 -- instance decls change: rules_vers)
711 mkUsage :: (ModuleName, Bool) -> Maybe Usage
712 mkUsage (mod_name, _)
713 | isNothing maybe_iface -- We can't depend on it if we didn't
714 || not (isHomeModule mod) -- even open the interface!
718 = Nothing -- Record no usage info
721 = Just (Usage { usg_name = moduleName mod,
723 usg_exports = export_vers,
724 usg_entities = ent_vers,
725 usg_rules = rules_vers })
727 maybe_iface = lookupIfaceByModName hpt pit mod_name
728 -- In one-shot mode, the interfaces for home-package
729 -- modules accumulate in the PIT not HPT. Sigh.
731 Just iface = maybe_iface
732 mod = mi_module iface
733 orphan_mod = mi_orphan iface
734 version_env = mi_ver_fn iface
735 mod_vers = mi_mod_vers iface
736 rules_vers = mi_rule_vers iface
737 all_imported = import_all mod
738 export_vers | all_imported = Just (mi_exp_vers iface)
739 | otherwise = Nothing
741 -- The sort is to put them into canonical order
742 used_occs = lookupModuleEnv ent_map mod `orElse` []
743 ent_vers :: [(OccName,Version)]
744 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
745 | occ <- sortLe (<=) used_occs]
749 mkIfaceExports :: NameSet -> [(ModuleName, [GenAvailInfo OccName])]
750 -- Group by module and sort by occurrence
751 -- This keeps the list in canonical order
752 mkIfaceExports exports
753 = [ (mkSysModuleNameFS fs, eltsFM avails)
754 | (fs, avails) <- fmToList groupFM
757 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
758 -- Deliberately use the FastString so we
759 -- get a canonical ordering
760 groupFM = foldl add emptyFM (nameSetToList exports)
762 add env name = addToFM_C add_avail env mod_fs
763 (unitFM avail_fs avail)
765 occ = nameOccName name
766 mod_fs = moduleNameFS (nameModuleName name)
767 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
768 | isTcOcc occ = AvailTC occ [occ]
769 | otherwise = Avail occ
770 avail_fs = occNameFS (availName avail)
771 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
773 add_item (AvailTC p occs) _ = AvailTC p (insert occ occs)
774 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
778 %************************************************************************
780 Load the old interface file for this module (unless
781 we have it aleady), and check whether it is up to date
784 %************************************************************************
787 checkOldIface :: HscEnv
789 -> FilePath -- Where the interface file is
790 -> Bool -- Source unchanged
791 -> Maybe ModIface -- Old interface from compilation manager, if any
792 -> IO (RecompileRequired, Maybe ModIface)
794 checkOldIface hsc_env mod iface_path source_unchanged maybe_iface
795 = do { showPass (hsc_dflags hsc_env)
796 ("Checking old interface for " ++ moduleUserString mod) ;
798 ; initIfaceCheck hsc_env $
799 check_old_iface mod iface_path source_unchanged maybe_iface
802 check_old_iface this_mod iface_path source_unchanged maybe_iface
803 = -- CHECK WHETHER THE SOURCE HAS CHANGED
804 ifM (not source_unchanged)
805 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
808 -- If the source has changed and we're in interactive mode, avoid reading
809 -- an interface; just return the one we might have been supplied with.
810 getGhciMode `thenM` \ ghci_mode ->
811 if (ghci_mode == Interactive) && not source_unchanged then
812 returnM (outOfDate, maybe_iface)
815 case maybe_iface of {
816 Just old_iface -> -- Use the one we already have
817 checkVersions source_unchanged old_iface `thenM` \ recomp ->
818 returnM (recomp, Just old_iface)
822 -- Try and read the old interface for the current module
823 -- from the .hi file left from the last time we compiled it
824 readIface (moduleName this_mod) iface_path False `thenM` \ read_result ->
825 case read_result of {
826 Left err -> -- Old interface file not found, or garbled; give up
827 traceIf (text "FYI: cannot read old interface file:"
828 $$ nest 4 err) `thenM_`
829 returnM (outOfDate, Nothing)
833 -- We have got the old iface; check its versions
834 checkVersions source_unchanged iface `thenM` \ recomp ->
835 returnM (recomp, Just iface)
839 @recompileRequired@ is called from the HscMain. It checks whether
840 a recompilation is required. It needs access to the persistent state,
841 finder, etc, because it may have to load lots of interface files to
842 check their versions.
845 type RecompileRequired = Bool
846 upToDate = False -- Recompile not required
847 outOfDate = True -- Recompile required
849 checkVersions :: Bool -- True <=> source unchanged
850 -> ModIface -- Old interface
851 -> IfG RecompileRequired
852 checkVersions source_unchanged iface
853 | not source_unchanged
856 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
857 ppr (mi_module iface) <> colon)
859 -- Source code unchanged and no errors yet... carry on
861 -- First put the dependent-module info in the envt, just temporarily,
862 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
863 -- It's just temporary because either the usage check will succeed
864 -- (in which case we are done with this module) or it'll fail (in which
865 -- case we'll compile the module from scratch anyhow).
866 ; mode <- getGhciMode
867 ; ifM (isOneShot mode)
868 (updateEps_ $ \eps -> eps { eps_is_boot = mod_deps })
870 ; checkList [checkModUsage u | u <- mi_usages iface]
873 -- This is a bit of a hack really
874 mod_deps :: ModuleEnv (ModuleName, IsBootInterface)
875 mod_deps = mkModDeps (dep_mods (mi_deps iface))
877 checkModUsage :: Usage -> IfG RecompileRequired
878 -- Given the usage information extracted from the old
879 -- M.hi file for the module being compiled, figure out
880 -- whether M needs to be recompiled.
882 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
883 usg_rules = old_rule_vers,
884 usg_exports = maybe_old_export_vers,
885 usg_entities = old_decl_vers })
886 = -- Load the imported interface is possible
888 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
890 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
892 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
893 -- Load the interface, but don't complain on failure;
894 -- Instead, get an Either back which we can test
897 Left exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
899 -- Couldn't find or parse a module mentioned in the
900 -- old interface file. Don't complain -- it might just be that
901 -- the current module doesn't need that import and it's been deleted
905 new_mod_vers = mi_mod_vers iface
906 new_decl_vers = mi_ver_fn iface
907 new_export_vers = mi_exp_vers iface
908 new_rule_vers = mi_rule_vers iface
911 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
912 if not recompile then
917 if checkExportList maybe_old_export_vers new_export_vers then
918 out_of_date_vers (ptext SLIT(" Export list changed"))
919 (fromJust maybe_old_export_vers)
924 if old_rule_vers /= new_rule_vers then
925 out_of_date_vers (ptext SLIT(" Rules changed"))
926 old_rule_vers new_rule_vers
929 -- CHECK ITEMS ONE BY ONE
930 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
932 returnM outOfDate -- This one failed, so just bail out now
934 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
937 ------------------------
938 checkModuleVersion old_mod_vers new_mod_vers
939 | new_mod_vers == old_mod_vers
940 = up_to_date (ptext SLIT("Module version unchanged"))
943 = out_of_date_vers (ptext SLIT(" Module version has changed"))
944 old_mod_vers new_mod_vers
946 ------------------------
947 checkExportList Nothing new_vers = upToDate
948 checkExportList (Just v) new_vers = v /= new_vers
950 ------------------------
951 checkEntityUsage new_vers (name,old_vers)
952 = case new_vers name of
954 Nothing -> -- We used it before, but it ain't there now
955 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
957 Just new_vers -- It's there, but is it up to date?
958 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
960 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
963 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
964 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
965 out_of_date_vers msg old_vers new_vers
966 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
968 ----------------------
969 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
970 -- This helper is used in two places
971 checkList [] = returnM upToDate
972 checkList (check:checks) = check `thenM` \ recompile ->
979 %************************************************************************
983 %************************************************************************
986 showIface :: FilePath -> IO ()
987 -- Raad binary interface, and print it out
988 showIface filename = do
989 -- skip the version check; we don't want to worry about profiled vs.
990 -- non-profiled interfaces, for example.
991 writeIORef v_IgnoreHiWay True
992 iface <- Binary.getBinFileWithDict filename
993 printDump (pprModIface iface)
999 pprModIface :: ModIface -> SDoc
1002 = vcat [ ptext SLIT("interface")
1003 <+> doubleQuotes (ftext (mi_package iface))
1004 <+> ppr (mi_module iface) <+> ppr (mi_mod_vers iface)
1006 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
1007 <+> int opt_HiVersion
1008 <+> ptext SLIT("where")
1009 , vcat (map pprExport (mi_exports iface))
1010 , pprDeps (mi_deps iface)
1011 , vcat (map pprUsage (mi_usages iface))
1012 , pprFixities (mi_fixities iface)
1013 , vcat (map pprIfaceDecl (mi_decls iface))
1014 , vcat (map ppr (mi_insts iface))
1015 , vcat (map ppr (mi_rules iface))
1016 , pprDeprecs (mi_deprecs iface)
1019 exp_vers = mi_exp_vers iface
1020 rule_vers = mi_rule_vers iface
1022 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1023 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1026 When printing export lists, we print like this:
1028 AvailTC C [C, x, y] C(x,y)
1029 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1032 pprExport :: IfaceExport -> SDoc
1033 pprExport (mod, items)
1034 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1036 pp_avail :: GenAvailInfo OccName -> SDoc
1037 pp_avail (Avail occ) = ppr occ
1038 pp_avail (AvailTC _ []) = empty
1039 pp_avail (AvailTC n (n':ns))
1040 | n==n' = ppr n <> pp_export ns
1041 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1043 pp_export [] = empty
1044 pp_export names = braces (hsep (map ppr names))
1046 pprUsage :: Usage -> SDoc
1048 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1049 int (usg_mod usage),
1050 pp_export_version (usg_exports usage),
1051 int (usg_rules usage),
1052 pp_versions (usg_entities usage) ]
1054 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1055 pp_export_version Nothing = empty
1056 pp_export_version (Just v) = int v
1058 pprDeps :: Dependencies -> SDoc
1059 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1060 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1061 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1062 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1065 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1066 ppr_boot True = text "[boot]"
1067 ppr_boot False = empty
1069 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1070 pprIfaceDecl (ver, decl)
1071 = ppr_vers ver <+> ppr decl
1073 -- Print the version for the decl
1074 ppr_vers v | v == initialVersion = empty
1077 pprFixities :: [(OccName, Fixity)] -> SDoc
1078 pprFixities [] = empty
1079 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1081 pprFix (occ,fix) = ppr fix <+> ppr occ
1083 pprDeprecs NoDeprecs = empty
1084 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1085 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1087 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)