2 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
7 pprModIface, 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 writeIfaceFile, -- Write the interface file
16 checkOldIface -- See if recompilation is required, by
17 -- comparing version information
21 -----------------------------------------------
22 MkIface.lhs deals with versioning
23 -----------------------------------------------
25 Here's the version-related info in an interface file
27 module Foo 8 -- module-version
28 3 -- export-list-version
30 Usages: -- Version info for what this compilation of Foo imported
31 Baz 3 -- Module version
32 [4] -- The export-list version if Foo depended on it
33 (g,2) -- Function and its version
34 (T,1) -- Type and its version
36 <version> f :: Int -> Int {- Unfolding: \x -> Wib.t[2] x -}
37 -- The [2] says that f's unfolding
38 -- mentions verison 2 of Wib.t
40 -----------------------------------------------
42 -----------------------------------------------
45 * In the mi_usages information in an interface, we record the
46 version number of each free variable of the module
48 * In mkIface, we compute the version number of each exported thing A.f
49 by comparing its A.f's info with its new info, and bumping its
50 version number if it differs. If A.f mentions B.g, and B.g's version
51 number has changed, then we count A.f as having changed too.
53 * In checkOldIface we compare the mi_usages for the module with
54 the actual version info for all each thing recorded in mi_usages
59 We count A.f as changing if its fixity changes
63 If a rule changes, we want to recompile any module that might be
64 affected by that rule. For non-orphan rules, this is relatively easy.
65 If module M defines f, and a rule for f, just arrange that the version
66 number for M.f changes if any of the rules for M.f change. Any module
67 that does not depend on M.f can't be affected by the rule-change
70 Orphan rules (ones whose 'head function' is not defined in M) are
71 harder. Here's what we do.
73 * We have a per-module orphan-rule version number which changes if
74 any orphan rule changes. (It's unaffected by non-orphan rules.)
76 * We record usage info for any orphan module 'below' this one,
77 giving the orphan-rule version number. We recompile if this
80 The net effect is that if an orphan rule changes, we recompile every
81 module above it. That's very conservative, but it's devilishly hard
82 to know what it might affect, so we just have to be conservative.
86 In an iface file we have
88 instance Eq a => Eq [a] = dfun29
91 We have a version number for dfun29, covering its unfolding
92 etc. Suppose we are compiling a module M that imports A only
93 indirectly. If typechecking M uses this instance decl, we record the
94 dependency on A.dfun29 as if it were a free variable of the module
95 (via the tcg_inst_usages accumulator). That means that A will appear
96 in M's usage list. If the shape of the instance declaration changes,
97 then so will dfun29's version, triggering a recompilation.
99 Adding an instance declaration, or changing an instance decl that is
100 not currently used, is more tricky. (This really only makes a
101 difference when we have overlapping instance decls, because then the
102 new instance decl might kick in to override the old one.) We handle
103 this in a very similar way that we handle rules above.
105 * For non-orphan instance decls, identify one locally-defined tycon/class
106 mentioned in the decl. Treat the instance decl as part of the defn of that
107 tycon/class, so that if the shape of the instance decl changes, so does the
108 tycon/class; that in turn will force recompilation of anything that uses
111 * For orphan instance decls, act the same way as for orphan rules.
112 Indeed, we use the same global orphan-rule version number.
116 mkUsageInfo figures out what the ``usage information'' for this
117 moudule is; that is, what it must record in its interface file as the
120 We produce a line for every module B below the module, A, currently being
123 to record the fact that A does import B indirectly. This is used to decide
124 to look to look for B.hi rather than B.hi-boot when compiling a module that
125 imports A. This line says that A imports B, but uses nothing in it.
126 So we'll get an early bale-out when compiling A if B's version changes.
128 The usage information records:
131 \item (a) anything reachable from its body code
132 \item (b) any module exported with a @module Foo@
133 \item (c) anything reachable from an exported item
136 Why (b)? Because if @Foo@ changes then this module's export list
137 will change, so we must recompile this module at least as far as
138 making a new interface file --- but in practice that means complete
141 Why (c)? Consider this:
143 module A( f, g ) where | module B( f ) where
144 import B( f ) | f = h 3
148 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
149 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
150 *identical* to what it was before. If anything about @B.f@ changes
151 than anyone who imports @A@ should be recompiled in case they use
152 @B.f@ (they'll get an early exit if they don't). So, if anything
153 about @B.f@ changes we'd better make sure that something in A.hi
154 changes, and the convenient way to do that is to record the version
155 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
156 complete recompiation of A, which is overkill but it's the only way to
157 write a new, slightly different, A.hi.
159 But the example is tricker. Even if @B.f@ doesn't change at all,
160 @B.h@ may do so, and this change may not be reflected in @f@'s version
161 number. But with -O, a module that imports A must be recompiled if
162 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
163 the occurrence of @B.f@ in the export list *just as if* it were in the
164 code of A, and thereby haul in all the stuff reachable from it.
166 *** Conclusion: if A mentions B.f in its export list,
167 behave just as if A mentioned B.f in its source code,
168 and slurp in B.f and all its transitive closure ***
170 [NB: If B was compiled with -O, but A isn't, we should really *still*
171 haul in all the unfoldings for B, in case the module that imports A *is*
172 compiled with -O. I think this is the case.]
176 #include "HsVersions.h"
179 import Packages ( isHomeModule, PackageIdH(..) )
180 import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..),
181 IfaceRule(..), IfaceInst(..), IfaceExtName(..),
182 eqIfDecl, eqIfRule, eqIfInst, IfaceEq(..), (&&&), bool,
183 eqMaybeBy, eqListBy, visibleIfConDecls,
184 tyThingToIfaceDecl, instanceToIfaceInst, coreRuleToIfaceRule )
185 import LoadIface ( readIface, loadInterface )
186 import BasicTypes ( Version, initialVersion, bumpVersion )
188 import HscTypes ( ModIface(..), ModDetails(..),
189 ModGuts(..), IfaceExport,
190 HscEnv(..), hscEPS, Dependencies(..), FixItem(..),
191 ModSummary(..), msHiFilePath,
192 mkIfaceDepCache, mkIfaceFixCache, mkIfaceVerCache,
194 GenAvailInfo(..), availName,
195 ExternalPackageState(..),
196 Usage(..), IsBootInterface,
197 Deprecs(..), IfaceDeprecs, Deprecations,
202 import Packages ( HomeModules )
203 import DynFlags ( GhcMode(..), DynFlags(..), DynFlag(..), dopt )
204 import StaticFlags ( opt_HiVersion )
205 import Name ( Name, nameModule, nameOccName, nameParent,
206 isExternalName, isInternalName, nameParent_maybe, isWiredInName,
207 isImplicitName, NamedThing(..) )
210 import OccName ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
212 OccSet, emptyOccSet, elemOccSet, occSetElts,
213 extendOccSet, extendOccSetList,
214 isEmptyOccSet, intersectOccSet, intersectsOccSet,
216 import Module ( Module, moduleFS,
217 ModLocation(..), mkModuleFS, moduleString,
218 ModuleEnv, emptyModuleEnv, lookupModuleEnv,
222 import Util ( createDirectoryHierarchy, directoryOf )
223 import Util ( sortLe, seqList )
224 import Binary ( getBinFileWithDict )
225 import BinIface ( writeBinIface, v_IgnoreHiWay )
226 import Unique ( Unique, Uniquable(..) )
227 import ErrUtils ( dumpIfSet_dyn, showPass )
228 import Digraph ( stronglyConnComp, SCC(..) )
229 import SrcLoc ( SrcSpan )
233 import DATA_IOREF ( writeIORef )
234 import Monad ( when )
235 import List ( insert )
236 import Maybes ( orElse, mapCatMaybes, isNothing, isJust,
237 expectJust, MaybeErr(..) )
242 %************************************************************************
244 \subsection{Completing an interface}
246 %************************************************************************
250 -> Maybe ModIface -- The old interface, if we have it
251 -> ModGuts -- Usages, deprecations, etc
252 -> ModDetails -- The trimmed, tidied interface
253 -> IO (ModIface, -- The new one, complete with decls and versions
254 Bool) -- True <=> there was an old Iface, and the new one
255 -- is identical, so no need to write it
257 mkIface hsc_env maybe_old_iface
258 (ModGuts{ mg_module = this_mod,
262 mg_home_mods = home_mods,
263 mg_rdr_env = rdr_env,
264 mg_fix_env = fix_env,
265 mg_deprecs = src_deprecs })
266 (ModDetails{ md_insts = insts,
269 md_exports = exports })
271 -- NB: notice that mkIface does not look at the bindings
272 -- only at the TypeEnv. The previous Tidy phase has
273 -- put exactly the info into the TypeEnv that we want
274 -- to expose in the interface
276 = do { eps <- hscEPS hsc_env
277 ; let { ext_nm_rhs = mkExtNameFn hsc_env home_mods eps this_mod
278 ; ext_nm_lhs = mkLhsNameFn this_mod
280 ; decls = [ tyThingToIfaceDecl ext_nm_rhs thing
281 | thing <- typeEnvElts type_env,
282 not (isImplicitName (getName thing)) ]
283 -- Don't put implicit Ids and class tycons in the interface file
285 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
286 ; deprecs = mkIfaceDeprec src_deprecs
287 ; iface_rules = map (coreRuleToIfaceRule ext_nm_lhs ext_nm_rhs) rules
288 ; iface_insts = map (instanceToIfaceInst ext_nm_lhs) insts
290 ; intermediate_iface = ModIface {
291 mi_module = this_mod,
292 mi_package = HomePackage,
296 mi_exports = mkIfaceExports exports,
297 mi_insts = sortLe le_inst iface_insts,
298 mi_rules = sortLe le_rule iface_rules,
299 mi_fixities = fixities,
300 mi_deprecs = deprecs,
301 mi_globals = Just rdr_env,
303 -- Left out deliberately: filled in by addVersionInfo
304 mi_mod_vers = initialVersion,
305 mi_exp_vers = initialVersion,
306 mi_rule_vers = initialVersion,
307 mi_orphan = False, -- Always set by addVersionInfo, but
308 -- it's a strict field, so we can't omit it.
309 mi_decls = deliberatelyOmitted "decls",
310 mi_ver_fn = deliberatelyOmitted "ver_fn",
312 -- And build the cached values
313 mi_dep_fn = mkIfaceDepCache deprecs,
314 mi_fix_fn = mkIfaceFixCache fixities }
316 -- Add version information
317 ; (new_iface, no_change_at_all, pp_diffs, pp_orphs)
318 = _scc_ "versioninfo"
319 addVersionInfo maybe_old_iface intermediate_iface decls
323 ; when (isJust pp_orphs && dopt Opt_WarnOrphans dflags)
324 (printDump (expectJust "mkIface" pp_orphs))
325 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
326 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
327 (pprModIface new_iface)
329 ; return (new_iface, no_change_at_all) }
331 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
332 i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
334 dflags = hsc_dflags hsc_env
335 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
338 -----------------------------
339 writeIfaceFile :: ModLocation -> ModIface -> IO ()
340 writeIfaceFile location new_iface
341 = do createDirectoryHierarchy (directoryOf hi_file_path)
342 writeBinIface hi_file_path new_iface
343 where hi_file_path = ml_hi_file location
346 -----------------------------
347 mkExtNameFn :: HscEnv -> HomeModules -> ExternalPackageState -> Module -> Name -> IfaceExtName
348 mkExtNameFn hsc_env hmods eps this_mod
351 hpt = hsc_HPT hsc_env
355 | mod == this_mod = case nameParent_maybe name of
356 Nothing -> LocalTop occ
357 Just par -> LocalTopSub occ (nameOccName par)
358 | isWiredInName name = ExtPkg mod occ
359 | isHomeModule hmods mod = HomePkg mod occ vers
360 | otherwise = ExtPkg mod occ
362 mod = nameModule name
363 occ = nameOccName name
364 par_occ = nameOccName (nameParent name)
365 -- The version of the *parent* is the one want
366 vers = lookupVersion mod par_occ
368 lookupVersion :: Module -> OccName -> Version
369 -- Even though we're looking up a home-package thing, in
370 -- one-shot mode the imported interfaces may be in the PIT
371 lookupVersion mod occ
372 = mi_ver_fn iface occ `orElse`
373 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
375 iface = lookupIfaceByModule hpt pit mod `orElse`
376 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
379 ---------------------
380 -- mkLhsNameFn ignores versioning info altogether
381 -- It is used for the LHS of instance decls and rules, where we
382 -- there's no point in recording version info
383 mkLhsNameFn :: Module -> Name -> IfaceExtName
384 mkLhsNameFn this_mod name
385 | isInternalName name = pprTrace "mkLhsNameFn: unexpected internal" (ppr name) $
386 LocalTop occ -- Should not happen
387 | mod == this_mod = LocalTop occ
388 | otherwise = ExtPkg mod occ
390 mod = nameModule name
391 occ = nameOccName name
394 -----------------------------
395 -- Compute version numbers for local decls
397 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
398 -> ModIface -- The new interface decls (lacking decls)
399 -> [IfaceDecl] -- The new decls
401 Bool, -- True <=> no changes at all; no need to write new Iface
403 Maybe SDoc) -- Warnings about orphans
405 addVersionInfo Nothing new_iface new_decls
406 -- No old interface, so definitely write a new one!
407 = (new_iface { mi_orphan = anyNothing ifInstOrph (mi_insts new_iface)
408 || anyNothing ifRuleOrph (mi_rules new_iface),
409 mi_decls = [(initialVersion, decl) | decl <- new_decls],
410 mi_ver_fn = \n -> Just initialVersion },
412 ptext SLIT("No old interface file"),
413 pprOrphans orph_insts orph_rules)
415 orph_insts = filter (isNothing . ifInstOrph) (mi_insts new_iface)
416 orph_rules = filter (isNothing . ifRuleOrph) (mi_rules new_iface)
418 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
419 mi_exp_vers = old_exp_vers,
420 mi_rule_vers = old_rule_vers,
421 mi_decls = old_decls,
422 mi_ver_fn = old_decl_vers,
423 mi_fix_fn = old_fixities }))
424 new_iface@(ModIface { mi_fix_fn = new_fixities })
427 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged"), pp_orphs)
428 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
429 nest 2 pp_diffs], pp_orphs)
431 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
432 mi_exp_vers = bump_unless no_export_change old_exp_vers,
433 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
434 mi_orphan = not (null new_orph_rules && null new_orph_insts),
435 mi_decls = decls_w_vers,
436 mi_ver_fn = mkIfaceVerCache decls_w_vers }
438 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
441 (old_non_orph_insts, old_orph_insts) = mkOrphMap ifInstOrph (mi_insts old_iface)
442 (new_non_orph_insts, new_orph_insts) = mkOrphMap ifInstOrph (mi_insts new_iface)
443 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
444 (lookupOccEnv old_non_orph_insts occ)
445 (lookupOccEnv new_non_orph_insts occ)
447 (old_non_orph_rules, old_orph_rules) = mkOrphMap ifRuleOrph (mi_rules old_iface)
448 (new_non_orph_rules, new_orph_rules) = mkOrphMap ifRuleOrph (mi_rules new_iface)
449 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
450 (lookupOccEnv old_non_orph_rules occ)
451 (lookupOccEnv new_non_orph_rules occ)
453 -- Computing what changed
454 no_output_change = no_decl_change && no_rule_change &&
455 no_export_change && no_deprec_change
456 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
457 no_decl_change = isEmptyOccSet changed_occs
458 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
459 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
460 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
462 -- If the usages havn't changed either, we don't need to write the interface file
463 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
464 mi_deps new_iface == mi_deps old_iface
465 no_change_at_all = no_output_change && no_other_changes
467 pp_diffs = vcat [pp_change no_export_change "Export list"
468 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
469 pp_change no_rule_change "Rules"
470 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
471 pp_change no_deprec_change "Deprecations" empty,
472 pp_change no_other_changes "Usages" empty,
474 pp_change True what info = empty
475 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
478 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
479 same_fixity n = bool (old_fixities n == new_fixities n)
482 -- Adding version info
483 new_version = bumpVersion old_mod_vers
484 add_vers decl | occ `elemOccSet` changed_occs = new_version
485 | otherwise = expectJust "add_vers" (old_decl_vers occ)
486 -- If it's unchanged, there jolly well
487 where -- should be an old version number
491 changed_occs :: OccSet
492 changed_occs = computeChangedOccs eq_info
494 eq_info :: [(OccName, IfaceEq)]
495 eq_info = map check_eq new_decls
496 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
497 = (occ, new_decl `eqIfDecl` old_decl &&&
498 eq_indirects new_decl)
499 | otherwise {- No corresponding old decl -}
502 occ = ifName new_decl
504 eq_indirects :: IfaceDecl -> IfaceEq
505 -- When seeing if two decls are the same, remember to
506 -- check whether any relevant fixity or rules have changed
507 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
508 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
509 = same_insts cls_occ &&&
510 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
511 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
512 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
513 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
514 eq_indirects other = Equal -- Synonyms and foreign declarations
516 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
517 eq_ind_occ occ = same_fixity occ &&& same_rules occ
518 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
522 pp_decl_diffs :: SDoc -- Nothing => no changes
524 | isEmptyOccSet changed_occs = empty
526 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
527 ptext SLIT("Version change for these decls:"),
528 nest 2 (vcat (map show_change new_decls))]
530 eq_env = mkOccEnv eq_info
532 | not (occ `elemOccSet` changed_occs) = empty
534 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
537 occ = ifName new_decl
538 why = case lookupOccEnv eq_env occ of
539 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
540 nest 2 (braces (fsep (map ppr (occSetElts
541 (occs `intersectOccSet` changed_occs)))))]
543 | Just old_decl <- lookupOccEnv old_decl_env occ
544 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
545 ptext SLIT("New:") <+> ppr new_decl]
547 -> ppr occ <+> ptext SLIT("only in new interface")
548 other -> pprPanic "MkIface.show_change" (ppr occ)
550 pp_orphs = pprOrphans new_orph_insts new_orph_rules
552 pprOrphans insts rules
553 | null insts && null rules = Nothing
556 if null insts then empty else
557 hang (ptext SLIT("Warning: orphan instances:"))
558 2 (vcat (map ppr insts)),
559 if null rules then empty else
560 hang (ptext SLIT("Warning: orphan rules:"))
561 2 (vcat (map ppr rules))
564 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
565 computeChangedOccs eq_info
566 = foldl add_changes emptyOccSet (stronglyConnComp edges)
568 edges :: [((OccName,IfaceEq), Unique, [Unique])]
569 edges = [ (node, getUnique occ, map getUnique occs)
570 | node@(occ, iface_eq) <- eq_info
571 , let occs = case iface_eq of
572 EqBut occ_set -> occSetElts occ_set
575 -- Changes in declarations
576 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
577 add_changes so_far (AcyclicSCC (occ, iface_eq))
578 | changedWrt so_far iface_eq -- This one has changed
579 = extendOccSet so_far occ
580 add_changes so_far (CyclicSCC pairs)
581 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
582 = extendOccSetList so_far (map fst pairs)
583 add_changes so_far other = so_far
585 changedWrt :: OccSet -> IfaceEq -> Bool
586 changedWrt so_far Equal = False
587 changedWrt so_far NotEqual = True
588 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
590 ----------------------
591 -- mkOrphMap partitions instance decls or rules into
592 -- (a) an OccEnv for ones that are not orphans,
593 -- mapping the local OccName to a list of its decls
594 -- (b) a list of orphan decls
595 mkOrphMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
596 -- Nothing for an orphan decl
597 -> [decl] -- Sorted into canonical order
598 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
599 -- each sublist in canonical order
600 [decl]) -- Orphan decls; in canonical order
601 mkOrphMap get_key decls
602 = foldl go (emptyOccEnv, []) decls
604 go (non_orphs, orphs) d
605 | Just occ <- get_key d
606 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
607 | otherwise = (non_orphs, d:orphs)
609 anyNothing :: (a -> Maybe b) -> [a] -> Bool
610 anyNothing p [] = False
611 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
613 ----------------------
614 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
615 mkIfaceDeprec NoDeprecs = NoDeprecs
616 mkIfaceDeprec (DeprecAll t) = DeprecAll t
617 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
619 ----------------------
620 bump_unless :: Bool -> Version -> Version
621 bump_unless True v = v -- True <=> no change
622 bump_unless False v = bumpVersion v
626 %*********************************************************
628 \subsection{Keeping track of what we've slurped, and version numbers}
630 %*********************************************************
634 mkUsageInfo :: HscEnv
636 -> ModuleEnv (Module, Bool, SrcSpan)
637 -> [(Module, IsBootInterface)]
638 -> NameSet -> IO [Usage]
639 mkUsageInfo hsc_env hmods dir_imp_mods dep_mods used_names
640 = do { eps <- hscEPS hsc_env
641 ; let usages = mk_usage_info (eps_PIT eps) hsc_env hmods
642 dir_imp_mods dep_mods used_names
643 ; usages `seqList` return usages }
644 -- seq the list of Usages returned: occasionally these
645 -- don't get evaluated for a while and we can end up hanging on to
646 -- the entire collection of Ifaces.
648 mk_usage_info pit hsc_env hmods dir_imp_mods dep_mods proto_used_names
649 = mapCatMaybes mkUsage dep_mods
650 -- ToDo: do we need to sort into canonical order?
652 hpt = hsc_HPT hsc_env
654 used_names = mkNameSet $ -- Eliminate duplicates
655 [ nameParent n -- Just record usage on the 'main' names
656 | n <- nameSetToList proto_used_names
657 , not (isWiredInName n) -- Don't record usages for wired-in names
658 , isExternalName n -- Ignore internal names
661 -- ent_map groups together all the things imported and used
662 -- from a particular module in this package
663 ent_map :: ModuleEnv [OccName]
664 ent_map = foldNameSet add_mv emptyModuleEnv used_names
665 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
667 occ = nameOccName name
668 mod = nameModule name
669 add_item occs _ = occ:occs
671 depend_on_exports mod = case lookupModuleEnv dir_imp_mods mod of
672 Just (_,no_imp,_) -> not no_imp
675 -- We want to create a Usage for a home module if
676 -- a) we used something from; has something in used_names
677 -- b) we imported all of it, even if we used nothing from it
678 -- (need to recompile if its export list changes: export_vers)
679 -- c) is a home-package orphan module (need to recompile if its
680 -- instance decls change: rules_vers)
681 mkUsage :: (Module, Bool) -> Maybe Usage
682 mkUsage (mod_name, _)
683 | isNothing maybe_iface -- We can't depend on it if we didn't
684 || not (isHomeModule hmods mod) -- even open the interface!
686 && isNothing export_vers
688 = Nothing -- Record no usage info
691 = Just (Usage { usg_name = mod,
693 usg_exports = export_vers,
694 usg_entities = ent_vers,
695 usg_rules = rules_vers })
697 maybe_iface = lookupIfaceByModule hpt pit mod_name
698 -- In one-shot mode, the interfaces for home-package
699 -- modules accumulate in the PIT not HPT. Sigh.
701 Just iface = maybe_iface
702 mod = mi_module iface
703 orphan_mod = mi_orphan iface
704 version_env = mi_ver_fn iface
705 mod_vers = mi_mod_vers iface
706 rules_vers = mi_rule_vers iface
707 export_vers | depend_on_exports mod = Just (mi_exp_vers iface)
708 | otherwise = Nothing
710 -- The sort is to put them into canonical order
711 used_occs = lookupModuleEnv ent_map mod `orElse` []
712 ent_vers :: [(OccName,Version)]
713 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
714 | occ <- sortLe (<=) used_occs]
718 mkIfaceExports :: NameSet -> [(Module, [GenAvailInfo OccName])]
719 -- Group by module and sort by occurrence
720 -- This keeps the list in canonical order
721 mkIfaceExports exports
722 = [ (mkModuleFS fs, eltsFM avails)
723 | (fs, avails) <- fmToList groupFM
726 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
727 -- Deliberately use the FastString so we
728 -- get a canonical ordering
729 groupFM = foldl add emptyFM (nameSetToList exports)
731 add env name = addToFM_C add_avail env mod_fs
732 (unitFM avail_fs avail)
734 occ = nameOccName name
735 mod_fs = moduleFS (nameModule name)
736 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
737 | isTcOcc occ = AvailTC occ [occ]
738 | otherwise = Avail occ
739 avail_fs = occNameFS (availName avail)
740 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
742 add_item (AvailTC p occs) _ = AvailTC p (List.insert occ occs)
743 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
747 %************************************************************************
749 Load the old interface file for this module (unless
750 we have it aleady), and check whether it is up to date
753 %************************************************************************
756 checkOldIface :: HscEnv
758 -> Bool -- Source unchanged
759 -> Maybe ModIface -- Old interface from compilation manager, if any
760 -> IO (RecompileRequired, Maybe ModIface)
762 checkOldIface hsc_env mod_summary source_unchanged maybe_iface
763 = do { showPass (hsc_dflags hsc_env)
764 ("Checking old interface for " ++ moduleString (ms_mod mod_summary)) ;
766 ; initIfaceCheck hsc_env $
767 check_old_iface mod_summary source_unchanged maybe_iface
770 check_old_iface mod_summary source_unchanged maybe_iface
771 = -- CHECK WHETHER THE SOURCE HAS CHANGED
772 ifM (not source_unchanged)
773 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
776 -- If the source has changed and we're in interactive mode, avoid reading
777 -- an interface; just return the one we might have been supplied with.
778 getGhcMode `thenM` \ ghc_mode ->
779 if (ghc_mode == Interactive || ghc_mode == JustTypecheck)
780 && not source_unchanged then
781 returnM (outOfDate, maybe_iface)
784 case maybe_iface of {
785 Just old_iface -> -- Use the one we already have
786 checkVersions source_unchanged old_iface `thenM` \ recomp ->
787 returnM (recomp, Just old_iface)
791 -- Try and read the old interface for the current module
792 -- from the .hi file left from the last time we compiled it
794 iface_path = msHiFilePath mod_summary
796 readIface (ms_mod mod_summary) iface_path False `thenM` \ read_result ->
797 case read_result of {
798 Failed err -> -- Old interface file not found, or garbled; give up
799 traceIf (text "FYI: cannot read old interface file:"
800 $$ nest 4 err) `thenM_`
801 returnM (outOfDate, Nothing)
805 -- We have got the old iface; check its versions
806 checkVersions source_unchanged iface `thenM` \ recomp ->
807 returnM (recomp, Just iface)
811 @recompileRequired@ is called from the HscMain. It checks whether
812 a recompilation is required. It needs access to the persistent state,
813 finder, etc, because it may have to load lots of interface files to
814 check their versions.
817 type RecompileRequired = Bool
818 upToDate = False -- Recompile not required
819 outOfDate = True -- Recompile required
821 checkVersions :: Bool -- True <=> source unchanged
822 -> ModIface -- Old interface
823 -> IfG RecompileRequired
824 checkVersions source_unchanged iface
825 | not source_unchanged
828 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
829 ppr (mi_module iface) <> colon)
831 -- Source code unchanged and no errors yet... carry on
833 -- First put the dependent-module info, read from the old interface, into the envt,
834 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
836 -- It's just temporary because either the usage check will succeed
837 -- (in which case we are done with this module) or it'll fail (in which
838 -- case we'll compile the module from scratch anyhow).
840 -- We do this regardless of compilation mode
841 ; updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
843 ; checkList [checkModUsage u | u <- mi_usages iface]
846 -- This is a bit of a hack really
847 mod_deps :: ModuleEnv (Module, IsBootInterface)
848 mod_deps = mkModDeps (dep_mods (mi_deps iface))
850 checkModUsage :: Usage -> IfG RecompileRequired
851 -- Given the usage information extracted from the old
852 -- M.hi file for the module being compiled, figure out
853 -- whether M needs to be recompiled.
855 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
856 usg_rules = old_rule_vers,
857 usg_exports = maybe_old_export_vers,
858 usg_entities = old_decl_vers })
859 = -- Load the imported interface is possible
861 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
863 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
865 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
866 -- Load the interface, but don't complain on failure;
867 -- Instead, get an Either back which we can test
870 Failed exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
872 -- Couldn't find or parse a module mentioned in the
873 -- old interface file. Don't complain -- it might just be that
874 -- the current module doesn't need that import and it's been deleted
878 new_mod_vers = mi_mod_vers iface
879 new_decl_vers = mi_ver_fn iface
880 new_export_vers = mi_exp_vers iface
881 new_rule_vers = mi_rule_vers iface
884 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
885 if not recompile then
890 if checkExportList maybe_old_export_vers new_export_vers then
891 out_of_date_vers (ptext SLIT(" Export list changed"))
892 (expectJust "checkModUsage" maybe_old_export_vers)
897 if old_rule_vers /= new_rule_vers then
898 out_of_date_vers (ptext SLIT(" Rules changed"))
899 old_rule_vers new_rule_vers
902 -- CHECK ITEMS ONE BY ONE
903 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
905 returnM outOfDate -- This one failed, so just bail out now
907 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
910 ------------------------
911 checkModuleVersion old_mod_vers new_mod_vers
912 | new_mod_vers == old_mod_vers
913 = up_to_date (ptext SLIT("Module version unchanged"))
916 = out_of_date_vers (ptext SLIT(" Module version has changed"))
917 old_mod_vers new_mod_vers
919 ------------------------
920 checkExportList Nothing new_vers = upToDate
921 checkExportList (Just v) new_vers = v /= new_vers
923 ------------------------
924 checkEntityUsage new_vers (name,old_vers)
925 = case new_vers name of
927 Nothing -> -- We used it before, but it ain't there now
928 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
930 Just new_vers -- It's there, but is it up to date?
931 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
933 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
936 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
937 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
938 out_of_date_vers msg old_vers new_vers
939 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
941 ----------------------
942 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
943 -- This helper is used in two places
944 checkList [] = returnM upToDate
945 checkList (check:checks) = check `thenM` \ recompile ->
952 %************************************************************************
956 %************************************************************************
959 showIface :: FilePath -> IO ()
960 -- Read binary interface, and print it out
961 showIface filename = do
962 -- skip the version check; we don't want to worry about profiled vs.
963 -- non-profiled interfaces, for example.
964 writeIORef v_IgnoreHiWay True
965 iface <- Binary.getBinFileWithDict filename
966 printDump (pprModIface iface)
972 pprModIface :: ModIface -> SDoc
975 = vcat [ ptext SLIT("interface")
976 <+> ppr_package (mi_package iface)
977 <+> ppr (mi_module iface) <+> pp_boot
978 <+> ppr (mi_mod_vers iface) <+> pp_sub_vers
979 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
980 <+> int opt_HiVersion
981 <+> ptext SLIT("where")
982 , vcat (map pprExport (mi_exports iface))
983 , pprDeps (mi_deps iface)
984 , vcat (map pprUsage (mi_usages iface))
985 , pprFixities (mi_fixities iface)
986 , vcat (map pprIfaceDecl (mi_decls iface))
987 , vcat (map ppr (mi_insts iface))
988 , vcat (map ppr (mi_rules iface))
989 , pprDeprecs (mi_deprecs iface)
992 pp_boot | mi_boot iface = ptext SLIT("[boot]")
994 ppr_package HomePackage = empty
995 ppr_package (ExtPackage id) = doubleQuotes (ppr id)
997 exp_vers = mi_exp_vers iface
998 rule_vers = mi_rule_vers iface
1000 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1001 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1004 When printing export lists, we print like this:
1006 AvailTC C [C, x, y] C(x,y)
1007 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1010 pprExport :: IfaceExport -> SDoc
1011 pprExport (mod, items)
1012 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1014 pp_avail :: GenAvailInfo OccName -> SDoc
1015 pp_avail (Avail occ) = ppr occ
1016 pp_avail (AvailTC _ []) = empty
1017 pp_avail (AvailTC n (n':ns))
1018 | n==n' = ppr n <> pp_export ns
1019 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1021 pp_export [] = empty
1022 pp_export names = braces (hsep (map ppr names))
1024 pprUsage :: Usage -> SDoc
1026 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1027 int (usg_mod usage),
1028 pp_export_version (usg_exports usage),
1029 int (usg_rules usage),
1030 pp_versions (usg_entities usage) ]
1032 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1033 pp_export_version Nothing = empty
1034 pp_export_version (Just v) = int v
1036 pprDeps :: Dependencies -> SDoc
1037 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1038 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1039 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1040 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1043 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1044 ppr_boot True = text "[boot]"
1045 ppr_boot False = empty
1047 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1048 pprIfaceDecl (ver, decl)
1049 = ppr_vers ver <+> ppr decl
1051 -- Print the version for the decl
1052 ppr_vers v | v == initialVersion = empty
1055 pprFixities :: [(OccName, Fixity)] -> SDoc
1056 pprFixities [] = empty
1057 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1059 pprFix (occ,fix) = ppr fix <+> ppr occ
1061 pprDeprecs NoDeprecs = empty
1062 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1063 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1065 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)