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_IgnoreHiVersion )
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 this_mod 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)
316 (printDump (write_diffs maybe_old_iface no_change_at_all pp_diffs))
317 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
318 (pprModIface new_iface)
322 r1 `lt_rule` r2 = ifRuleName r1 < ifRuleName r2
323 i1 `lt_inst` i2 = ifDFun i1 < ifDFun i2
325 dflags = hsc_dflags hsc_env
326 ghci_mode = hsc_mode hsc_env
327 hi_file_path = ml_hi_file location
328 omit_prags = dopt Opt_OmitInterfacePragmas dflags
330 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
332 -----------------------------
333 mkExtNameFn :: HscEnv -> ExternalPackageState -> ModuleName -> Name -> IfaceExtName
334 mkExtNameFn hsc_env eps this_mod
337 hpt = hsc_HPT hsc_env
341 | mod_nm == this_mod = case nameParent_maybe name of
342 Nothing -> LocalTop occ
343 Just par -> LocalTopSub occ (nameOccName par)
344 | isWiredInName name = ExtPkg mod_nm occ
345 | isHomeModule mod = HomePkg mod_nm occ vers
346 | otherwise = ExtPkg mod_nm occ
348 mod = nameModule name
349 mod_nm = moduleName mod
350 occ = nameOccName name
351 par_occ = nameOccName (nameParent name)
352 -- The version of the *parent* is the one want
353 vers = lookupVersion mod_nm par_occ
355 lookupVersion :: ModuleName -> OccName -> Version
356 -- Even though we're looking up a home-package thing, in
357 -- one-shot mode the imported interfaces may be in the PIT
358 lookupVersion mod occ
359 = mi_ver_fn iface occ `orElse`
360 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
362 iface = lookupIfaceByModName hpt pit mod `orElse`
363 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
365 -----------------------------
366 -- Compute version numbers for local decls
368 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
369 -> ModIface -- The new interface decls (lacking decls)
370 -> [IfaceDecl] -- The new decls
372 Bool, -- True <=> no changes at all; no need to write new Iface
375 addVersionInfo Nothing new_iface new_decls
376 -- No old interface, so definitely write a new one!
377 = (new_iface { mi_orphan = anyNothing getInstKey (mi_insts new_iface)
378 || anyNothing getRuleKey (mi_rules new_iface),
379 mi_decls = [(initialVersion, decl) | decl <- new_decls],
380 mi_ver_fn = \n -> Just initialVersion },
381 False, text "No old interface available")
383 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
384 mi_exp_vers = old_exp_vers,
385 mi_rule_vers = old_rule_vers,
386 mi_decls = old_decls,
387 mi_ver_fn = old_decl_vers,
388 mi_fix_fn = old_fixities }))
389 new_iface@(ModIface { mi_fix_fn = new_fixities })
392 | no_change_at_all = (old_iface, True, empty)
393 | otherwise = (final_iface, False, pp_diffs)
395 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
396 mi_exp_vers = bump_unless no_export_change old_exp_vers,
397 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
398 mi_orphan = not (null new_orph_rules && null new_orph_insts),
399 mi_decls = decls_w_vers,
400 mi_ver_fn = mkIfaceVerCache decls_w_vers }
402 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
405 (new_non_orph_insts, new_orph_insts) = mkRuleMap getInstKey (mi_insts new_iface)
406 (old_non_orph_insts, old_orph_insts) = mkRuleMap getInstKey (mi_insts old_iface)
407 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
408 (lookupOccEnv old_non_orph_insts occ)
409 (lookupOccEnv new_non_orph_insts occ)
411 (old_non_orph_rules, old_orph_rules) = mkRuleMap getRuleKey (mi_rules old_iface)
412 (new_non_orph_rules, new_orph_rules) = mkRuleMap getRuleKey (mi_rules new_iface)
413 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
414 (lookupOccEnv old_non_orph_rules occ)
415 (lookupOccEnv new_non_orph_rules occ)
417 -- Computing what changed
418 no_output_change = no_decl_change && no_rule_change &&
419 no_export_change && no_deprec_change
420 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
421 no_decl_change = isEmptyOccSet changed_occs
422 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
423 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
424 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
426 -- If the usages havn't changed either, we don't need to write the interface file
427 -- Question: should we also check for equality of mi_deps?
428 no_other_changes = mi_usages new_iface == mi_usages old_iface
429 no_change_at_all = no_output_change && no_other_changes
431 pp_diffs = vcat [pp_decl_diffs,
432 pp_change no_export_change "Export list"
433 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
434 pp_change no_rule_change "Rules"
435 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
436 pp_change no_deprec_change "Deprecations" empty,
437 pp_change no_other_changes "Usages" empty]
438 pp_change True what info = empty
439 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
442 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
443 same_fixity n = bool (old_fixities n == new_fixities n)
446 -- Adding version info
447 new_version = bumpVersion old_mod_vers
448 add_vers decl | occ `elemOccSet` changed_occs = new_version
449 | otherwise = expectJust "add_vers" (old_decl_vers occ)
450 -- If it's unchanged, there jolly well
451 where -- should be an old version number
455 changed_occs :: OccSet
456 changed_occs = computeChangedOccs eq_info
458 eq_info :: [(OccName, IfaceEq)]
459 eq_info = map check_eq new_decls
460 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
461 = (occ, new_decl `eqIfDecl` old_decl &&&
462 eq_indirects new_decl)
463 | otherwise {- No corresponding old decl -}
466 occ = ifName new_decl
468 eq_indirects :: IfaceDecl -> IfaceEq
469 -- When seeing if two decls are the same, remember to
470 -- check whether any relevant fixity or rules have changed
471 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
472 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
473 = same_insts cls_occ &&&
474 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
475 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
476 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
477 eq_ind_occs [occ | IfaceConDecl occ _ _ _ _ _ <- visibleDataCons cons]
478 eq_indirects other = Equal -- Synonyms and foreign declarations
480 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
481 eq_ind_occ occ = same_fixity occ &&& same_rules occ
482 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
486 pp_decl_diffs :: SDoc -- Nothing => no changes
488 | isEmptyOccSet changed_occs = empty
490 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
491 ptext SLIT("Version change for these decls:"),
492 nest 2 (vcat (map show_change new_decls))]
494 eq_env = mkOccEnv eq_info
496 | not (occ `elemOccSet` changed_occs) = empty
498 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
501 occ = ifName new_decl
502 why = case lookupOccEnv eq_env occ of
503 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
504 nest 2 (braces (fsep (map ppr (occSetElts
505 (occs `intersectOccSet` changed_occs)))))]
507 | Just old_decl <- lookupOccEnv old_decl_env occ
508 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
509 ptext SLIT("New:") <+> ppr new_decl]
511 -> ppr occ <+> ptext SLIT("only in new interface")
512 other -> pprPanic "MkIface.show_change" (ppr occ)
515 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
516 computeChangedOccs eq_info
517 = foldl add_changes emptyOccSet (stronglyConnComp edges)
519 edges :: [((OccName,IfaceEq), Unique, [Unique])]
520 edges = [ (node, getUnique occ, map getUnique occs)
521 | node@(occ, iface_eq) <- eq_info
522 , let occs = case iface_eq of
523 EqBut occ_set -> occSetElts occ_set
526 -- Changes in declarations
527 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
528 add_changes so_far (AcyclicSCC (occ, iface_eq))
529 | changedWrt so_far iface_eq -- This one has changed
530 = extendOccSet so_far occ
531 add_changes so_far (CyclicSCC pairs)
532 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
533 = extendOccSetList so_far (map fst pairs)
534 add_changes so_far other = so_far
536 changedWrt :: OccSet -> IfaceEq -> Bool
537 changedWrt so_far Equal = False
538 changedWrt so_far NotEqual = True
539 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
541 ----------------------
542 -- mkRuleMap partitions instance decls or rules into
543 -- (a) an OccEnv for ones that are not orphans,
544 -- mapping the local OccName to a list of its decls
545 -- (b) a list of orphan decls
546 mkRuleMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
547 -- Nothing for an orphan decl
548 -> [decl] -- Sorted into canonical order
549 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
550 -- each sublist in canonical order
551 [decl]) -- Orphan decls; in canonical order
552 mkRuleMap get_key decls
553 = foldl go (emptyOccEnv, []) decls
555 go (non_orphs, orphs) d
556 | Just occ <- get_key d
557 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
558 | otherwise = (non_orphs, d:orphs)
560 -- getXxKey: find at least one local OccName that belongs to this decl
562 getInstKey :: IfaceInst -> Maybe OccName
563 getInstKey (IfaceInst {ifInstHead = inst_ty})
564 = case [occ | LocalTop occ <- cls_ext : tc_exts] of
568 (cls_ext, tcs) = ifaceInstGates inst_ty
569 tc_exts = [tc | IfaceTc tc <- tcs]
570 -- Ignore the wired-in IfaceTyCons; the class will do as the key
572 getRuleKey :: IfaceRule -> Maybe OccName
573 getRuleKey (IfaceRule {ifRuleHead = LocalTop occ}) = Just occ
574 getRuleKey other = Nothing
576 anyNothing :: (a -> Maybe b) -> [a] -> Bool
577 anyNothing p [] = False
578 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
580 ----------------------
581 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
582 mkIfaceDeprec NoDeprecs = NoDeprecs
583 mkIfaceDeprec (DeprecAll t) = DeprecAll t
584 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLt (<) (nameEnvElts env))
586 ----------------------
587 write_diffs :: Maybe ModIface -> Bool -> SDoc -> SDoc
588 write_diffs Nothing _ _ = ptext SLIT("NO OLD INTERFACE FILE")
589 write_diffs (Just _) True _ = ptext SLIT("INTERFACE UNCHANGED")
590 write_diffs (Just _) False diffs = sep [ptext SLIT("INTERFACE HAS CHANGED"), nest 2 diffs]
592 ----------------------
593 bump_unless :: Bool -> Version -> Version
594 bump_unless True v = v -- True <=> no change
595 bump_unless False v = bumpVersion v
599 %*********************************************************
601 \subsection{Keeping track of what we've slurped, and version numbers}
603 %*********************************************************
607 mkUsageInfo :: HscEnv -> ImportAvails -> NameSet -> IO [Usage]
609 (ImportAvails { imp_mods = dir_imp_mods,
610 imp_dep_mods = dep_mods })
612 = do { eps <- hscEPS hsc_env
613 ; return (mk_usage_info (eps_PIT eps) (hsc_HPT hsc_env)
614 dir_imp_mods dep_mods used_names) }
616 mk_usage_info pit hpt dir_imp_mods dep_mods proto_used_names
617 = -- seq the list of Usages returned: occasionally these
618 -- don't get evaluated for a while and we can end up hanging on to
619 -- the entire collection of Ifaces.
620 usages `seqList` usages
622 used_names = mkNameSet $ -- Eliminate duplicates
623 [ nameParent n -- Just record usage on the 'main' names
624 | n <- nameSetToList proto_used_names
625 , not (isWiredInName n) -- Don't record usages for wired-in names
626 , isExternalName n -- Ignore internal names
629 -- ent_map groups together all the things imported and used
630 -- from a particular module in this package
631 ent_map :: ModuleEnv [OccName]
632 ent_map = foldNameSet add_mv emptyModuleEnv used_names
633 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
635 occ = nameOccName name
636 mod = nameModule name
637 add_item occs _ = occ:occs
639 usages = mapCatMaybes mkUsage (moduleEnvElts dep_mods)
640 -- ToDo: do we need to sort into canonical order?
642 import_all mod = case lookupModuleEnv dir_imp_mods mod of
643 Just (_,imp_all) -> isNothing imp_all
646 -- We want to create a Usage for a home module if
647 -- a) we used something from; has something in used_names
648 -- b) we imported all of it, even if we used nothing from it
649 -- (need to recompile if its export list changes: export_vers)
650 -- c) is a home-package orphan module (need to recompile if its
651 -- instance decls change: rules_vers)
652 mkUsage :: (ModuleName, Bool) -> Maybe Usage
653 mkUsage (mod_name, _)
654 | isNothing maybe_iface -- We can't depend on it if we didn't
655 || not (isHomeModule mod) -- even open the interface!
659 = Nothing -- Record no usage info
662 = Just (Usage { usg_name = moduleName mod,
664 usg_exports = export_vers,
665 usg_entities = ent_vers,
666 usg_rules = rules_vers })
668 maybe_iface = lookupIfaceByModName hpt pit mod_name
669 -- In one-shot mode, the interfaces for home-package
670 -- modules accumulate in the PIT not HPT. Sigh.
672 Just iface = maybe_iface
673 mod = mi_module iface
674 orphan_mod = mi_orphan iface
675 version_env = mi_ver_fn iface
676 mod_vers = mi_mod_vers iface
677 rules_vers = mi_rule_vers iface
678 all_imported = import_all mod
679 export_vers | all_imported = Just (mi_exp_vers iface)
680 | otherwise = Nothing
682 -- The sort is to put them into canonical order
683 used_occs = lookupModuleEnv ent_map mod `orElse` []
684 ent_vers :: [(OccName,Version)]
685 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
686 | occ <- sortLt (<) used_occs]
690 groupAvails :: Module -> Avails -> [(ModuleName, [GenAvailInfo OccName])]
691 -- Group by module and sort by occurrence
692 -- This keeps the list in canonical order
693 groupAvails this_mod avails
694 = [ (mkSysModuleNameFS fs, sortLt lt avails)
695 | (fs,avails) <- fmToList groupFM
698 groupFM :: FiniteMap FastString [GenAvailInfo OccName]
699 -- Deliberately use the FastString so we
700 -- get a canonical ordering
701 groupFM = foldl add emptyFM avails
703 add env avail = addToFM_C (\old _ -> avail':old) env mod_fs [avail']
705 mod_fs = moduleNameFS (moduleName avail_mod)
706 avail_mod = nameModule (availName avail)
707 avail' = sortAvail avail
709 a1 `lt` a2 = availName a1 < availName a2
711 sortAvail :: AvailInfo -> GenAvailInfo OccName
712 -- Convert to OccName, and sort the sub-names into canonical order
713 -- The canonical order has the "main name" at the beginning
714 -- (if it's there at all)
715 sortAvail (Avail n) = Avail (nameOccName n)
716 sortAvail (AvailTC n ns)
717 | n `elem` ns = AvailTC occ (occ : mk_occs (filter (/= n) ns))
718 | otherwise = AvailTC occ ( mk_occs ns)
721 mk_occs ns = sortLt (<) (map nameOccName ns)
724 %************************************************************************
726 Load the old interface file for this module (unless
727 we have it aleady), and check whether it is up to date
730 %************************************************************************
733 checkOldIface :: HscEnv
735 -> FilePath -- Where the interface file is
736 -> Bool -- Source unchanged
737 -> Maybe ModIface -- Old interface from compilation manager, if any
738 -> IO (RecompileRequired, Maybe ModIface)
740 checkOldIface hsc_env mod iface_path source_unchanged maybe_iface
741 = do { showPass (hsc_dflags hsc_env)
742 ("Checking old interface for " ++ moduleUserString mod) ;
744 ; initIfaceCheck hsc_env $
745 check_old_iface mod iface_path source_unchanged maybe_iface
748 check_old_iface this_mod iface_path source_unchanged maybe_iface
749 = -- CHECK WHETHER THE SOURCE HAS CHANGED
750 ifM (not source_unchanged)
751 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
754 -- If the source has changed and we're in interactive mode, avoid reading
755 -- an interface; just return the one we might have been supplied with.
756 getGhciMode `thenM` \ ghci_mode ->
757 if (ghci_mode == Interactive) && not source_unchanged then
758 returnM (outOfDate, maybe_iface)
761 case maybe_iface of {
762 Just old_iface -> -- Use the one we already have
763 checkVersions source_unchanged old_iface `thenM` \ recomp ->
764 returnM (recomp, Just old_iface)
768 -- Try and read the old interface for the current module
769 -- from the .hi file left from the last time we compiled it
770 readIface (moduleName this_mod) iface_path False `thenM` \ read_result ->
771 case read_result of {
772 Left err -> -- Old interface file not found, or garbled; give up
773 traceHiDiffs (text "FYI: cannot read old interface file:"
774 $$ nest 4 err) `thenM_`
775 returnM (outOfDate, Nothing)
779 -- We have got the old iface; check its versions
780 checkVersions source_unchanged iface `thenM` \ recomp ->
781 returnM (recomp, Just iface)
785 @recompileRequired@ is called from the HscMain. It checks whether
786 a recompilation is required. It needs access to the persistent state,
787 finder, etc, because it may have to load lots of interface files to
788 check their versions.
791 type RecompileRequired = Bool
792 upToDate = False -- Recompile not required
793 outOfDate = True -- Recompile required
795 checkVersions :: Bool -- True <=> source unchanged
796 -> ModIface -- Old interface
797 -> IfG RecompileRequired
798 checkVersions source_unchanged iface
799 | not source_unchanged
802 = traceHiDiffs (text "Considering whether compilation is required for" <+>
803 ppr (mi_module iface) <> colon) `thenM_`
805 -- Source code unchanged and no errors yet... carry on
806 -- First put the dependent-module info in the envt, just temporarily,
807 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
808 -- It's just temporary because either the usage check will succeed
809 -- (in which case we are done with this module) or it'll fail (in which
810 -- case we'll compile the module from scratch anyhow).
811 updGblEnv (\ gbl -> gbl { if_is_boot = mod_deps }) (
812 checkList [checkModUsage u | u <- mi_usages iface]
815 -- This is a bit of a hack really
816 mod_deps :: ModuleEnv (ModuleName, IsBootInterface)
817 mod_deps = mkModDeps (dep_mods (mi_deps iface))
819 checkModUsage :: Usage -> IfG RecompileRequired
820 -- Given the usage information extracted from the old
821 -- M.hi file for the module being compiled, figure out
822 -- whether M needs to be recompiled.
824 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
825 usg_rules = old_rule_vers,
826 usg_exports = maybe_old_export_vers,
827 usg_entities = old_decl_vers })
828 = -- Load the imported interface is possible
830 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
832 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
834 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
835 -- Load the interface, but don't complain on failure;
836 -- Instead, get an Either back which we can test
839 Left exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
841 -- Couldn't find or parse a module mentioned in the
842 -- old interface file. Don't complain -- it might just be that
843 -- the current module doesn't need that import and it's been deleted
847 new_mod_vers = mi_mod_vers iface
848 new_decl_vers = mi_ver_fn iface
849 new_export_vers = mi_exp_vers iface
850 new_rule_vers = mi_rule_vers iface
853 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
854 if not recompile then
859 if checkExportList maybe_old_export_vers new_export_vers then
860 out_of_date_vers (ptext SLIT(" Export list changed"))
861 (fromJust maybe_old_export_vers)
866 if old_rule_vers /= new_rule_vers then
867 out_of_date_vers (ptext SLIT(" Rules changed"))
868 old_rule_vers new_rule_vers
871 -- CHECK ITEMS ONE BY ONE
872 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
874 returnM outOfDate -- This one failed, so just bail out now
876 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
879 ------------------------
880 checkModuleVersion old_mod_vers new_mod_vers
881 | new_mod_vers == old_mod_vers
882 = up_to_date (ptext SLIT("Module version unchanged"))
885 = out_of_date_vers (ptext SLIT(" Module version has changed"))
886 old_mod_vers new_mod_vers
888 ------------------------
889 checkExportList Nothing new_vers = upToDate
890 checkExportList (Just v) new_vers = v /= new_vers
892 ------------------------
893 checkEntityUsage new_vers (name,old_vers)
894 = case new_vers name of
896 Nothing -> -- We used it before, but it ain't there now
897 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
899 Just new_vers -- It's there, but is it up to date?
900 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
902 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
905 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
906 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
907 out_of_date_vers msg old_vers new_vers
908 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
910 ----------------------
911 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
912 -- This helper is used in two places
913 checkList [] = returnM upToDate
914 checkList (check:checks) = check `thenM` \ recompile ->
921 %************************************************************************
925 %************************************************************************
928 showIface :: FilePath -> IO ()
929 -- Raad binary interface, and print it out
930 showIface filename = do
931 -- skip the version check; we don't want to worry about profiled vs.
932 -- non-profiled interfaces, for example.
933 writeIORef v_IgnoreHiVersion True
934 iface <- Binary.getBinFileWithDict filename
935 printDump (pprModIface iface)
941 pprModIface :: ModIface -> SDoc
944 = vcat [ ptext SLIT("interface")
945 <+> doubleQuotes (ftext (mi_package iface))
946 <+> ppr (mi_module iface) <+> ppr (mi_mod_vers iface)
948 <+> (if mi_orphan iface then char '!' else empty)
949 <+> int opt_HiVersion
950 <+> ptext SLIT("where")
951 , vcat (map pprExport (mi_exports iface))
952 , pprDeps (mi_deps iface)
953 , vcat (map pprUsage (mi_usages iface))
954 , pprFixities (mi_fixities iface)
955 , vcat (map pprIfaceDecl (mi_decls iface))
956 , vcat (map ppr (mi_insts iface))
957 , vcat (map ppr (mi_rules iface))
958 , pprDeprecs (mi_deprecs iface)
961 exp_vers = mi_exp_vers iface
962 rule_vers = mi_rule_vers iface
964 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
965 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
968 When printing export lists, we print like this:
970 AvailTC C [C, x, y] C(x,y)
971 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
974 pprExport :: IfaceExport -> SDoc
975 pprExport (mod, items)
976 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
978 pp_avail :: GenAvailInfo OccName -> SDoc
979 pp_avail (Avail occ) = ppr occ
980 pp_avail (AvailTC _ []) = empty
981 pp_avail (AvailTC n (n':ns))
982 | n==n' = ppr n <> pp_export ns
983 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
986 pp_export names = braces (hsep (map ppr names))
988 pprUsage :: Usage -> SDoc
990 = hsep [ptext SLIT("import"), ppr (usg_name usage),
992 pp_export_version (usg_exports usage),
993 int (usg_rules usage),
994 pp_versions (usg_entities usage) ]
996 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
997 pp_export_version Nothing = empty
998 pp_export_version (Just v) = int v
1000 pprDeps :: Dependencies -> SDoc
1001 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1002 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1003 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1004 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1007 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1008 ppr_boot True = text "[boot]"
1009 ppr_boot False = empty
1011 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1012 pprIfaceDecl (ver, decl)
1013 = ppr_vers ver <+> ppr decl
1015 -- Print the version for the decl
1016 ppr_vers v | v == initialVersion = empty
1019 pprFixities :: [(OccName, Fixity)] -> SDoc
1020 pprFixities [] = empty
1021 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1023 pprFix (occ,fix) = ppr fix <+> ppr occ
1025 pprDeprecs NoDeprecs = empty
1026 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1027 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1029 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)