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 TcRnTypes ( mkModDeps )
189 import HscTypes ( ModIface(..),
190 ModGuts(..), ModGuts, IfaceExport,
191 HscEnv(..), hscEPS, Dependencies(..), FixItem(..),
192 ModSummary(..), msHiFilePath,
193 mkIfaceDepCache, mkIfaceFixCache, mkIfaceVerCache,
195 GenAvailInfo(..), availName,
196 ExternalPackageState(..),
197 Usage(..), IsBootInterface,
198 Deprecs(..), IfaceDeprecs, Deprecations,
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(..), mkSysModuleFS, moduleUserString,
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 fromJust, expectJust, MaybeErr(..) )
242 %************************************************************************
244 \subsection{Completing an interface}
246 %************************************************************************
250 -> Maybe ModIface -- The old interface, if we have it
251 -> ModGuts -- The compiled, tidied module
252 -> IO (ModIface, -- The new one, complete with decls and versions
253 Bool) -- True <=> there was an old Iface, and the new one
254 -- is identical, so no need to write it
256 mkIface hsc_env maybe_old_iface
257 guts@ModGuts{ mg_module = this_mod,
261 mg_exports = exports,
262 mg_rdr_env = rdr_env,
263 mg_fix_env = fix_env,
264 mg_deprecs = src_deprecs,
267 mg_types = type_env }
268 -- NB: notice that mkIface does not look at the bindings
269 -- only at the TypeEnv. The previous Tidy phase has
270 -- put exactly the info into the TypeEnv that we want
271 -- to expose in the interface
273 = do { eps <- hscEPS hsc_env
274 ; let { ext_nm_rhs = mkExtNameFn hsc_env eps this_mod
275 ; ext_nm_lhs = mkLhsNameFn this_mod
277 ; decls = [ tyThingToIfaceDecl ext_nm_rhs thing
278 | thing <- typeEnvElts type_env,
279 not (isImplicitName (getName thing)) ]
280 -- Don't put implicit Ids and class tycons in the interface file
282 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
283 ; deprecs = mkIfaceDeprec src_deprecs
284 ; iface_rules = map (coreRuleToIfaceRule ext_nm_lhs ext_nm_rhs) rules
285 ; iface_insts = map (instanceToIfaceInst ext_nm_lhs) insts
287 ; intermediate_iface = ModIface {
288 mi_module = this_mod,
289 mi_package = HomePackage,
293 mi_exports = mkIfaceExports exports,
294 mi_insts = sortLe le_inst iface_insts,
295 mi_rules = sortLe le_rule iface_rules,
296 mi_fixities = fixities,
297 mi_deprecs = deprecs,
298 mi_globals = Just rdr_env,
300 -- Left out deliberately: filled in by addVersionInfo
301 mi_mod_vers = initialVersion,
302 mi_exp_vers = initialVersion,
303 mi_rule_vers = initialVersion,
304 mi_orphan = False, -- Always set by addVersionInfo, but
305 -- it's a strict field, so we can't omit it.
306 mi_decls = deliberatelyOmitted "decls",
307 mi_ver_fn = deliberatelyOmitted "ver_fn",
309 -- And build the cached values
310 mi_dep_fn = mkIfaceDepCache deprecs,
311 mi_fix_fn = mkIfaceFixCache fixities }
313 -- Add version information
314 ; (new_iface, no_change_at_all, pp_diffs, pp_orphs)
315 = _scc_ "versioninfo"
316 addVersionInfo maybe_old_iface intermediate_iface decls
320 ; when (isJust pp_orphs && dopt Opt_WarnOrphans dflags)
321 (printDump (fromJust pp_orphs))
322 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
323 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
324 (pprModIface new_iface)
326 ; return (new_iface, no_change_at_all) }
328 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
329 i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
331 dflags = hsc_dflags hsc_env
332 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
335 -----------------------------
336 writeIfaceFile :: HscEnv -> ModLocation -> ModIface -> Bool -> IO ()
337 -- Write the interface file, if necessary
338 writeIfaceFile hsc_env location new_iface no_change_at_all
339 | no_change_at_all = return ()
340 | ghc_mode == Interactive = return ()
342 = do { createDirectoryHierarchy (directoryOf hi_file_path)
343 ; writeBinIface hi_file_path new_iface }
345 ghc_mode = ghcMode (hsc_dflags hsc_env)
346 hi_file_path = ml_hi_file location
349 -----------------------------
350 mkExtNameFn :: HscEnv -> ExternalPackageState -> Module -> Name -> IfaceExtName
351 mkExtNameFn hsc_env eps this_mod
354 dflags = hsc_dflags hsc_env
355 hpt = hsc_HPT hsc_env
359 | mod == this_mod = case nameParent_maybe name of
360 Nothing -> LocalTop occ
361 Just par -> LocalTopSub occ (nameOccName par)
362 | isWiredInName name = ExtPkg mod occ
363 | isHomeModule dflags mod = HomePkg mod occ vers
364 | otherwise = ExtPkg mod occ
366 mod = nameModule name
367 occ = nameOccName name
368 par_occ = nameOccName (nameParent name)
369 -- The version of the *parent* is the one want
370 vers = lookupVersion mod par_occ
372 lookupVersion :: Module -> OccName -> Version
373 -- Even though we're looking up a home-package thing, in
374 -- one-shot mode the imported interfaces may be in the PIT
375 lookupVersion mod occ
376 = mi_ver_fn iface occ `orElse`
377 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
379 iface = lookupIfaceByModule hpt pit mod `orElse`
380 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
383 ---------------------
384 -- mkLhsNameFn ignores versioning info altogether
385 -- It is used for the LHS of instance decls and rules, where we
386 -- there's no point in recording version info
387 mkLhsNameFn :: Module -> Name -> IfaceExtName
388 mkLhsNameFn this_mod name
389 | isInternalName name = pprTrace "mkLhsNameFn: unexpected internal" (ppr name) $
390 LocalTop occ -- Should not happen
391 | mod == this_mod = LocalTop occ
392 | otherwise = ExtPkg mod occ
394 mod = nameModule name
395 occ = nameOccName name
398 -----------------------------
399 -- Compute version numbers for local decls
401 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
402 -> ModIface -- The new interface decls (lacking decls)
403 -> [IfaceDecl] -- The new decls
405 Bool, -- True <=> no changes at all; no need to write new Iface
407 Maybe SDoc) -- Warnings about orphans
409 addVersionInfo Nothing new_iface new_decls
410 -- No old interface, so definitely write a new one!
411 = (new_iface { mi_orphan = anyNothing ifInstOrph (mi_insts new_iface)
412 || anyNothing ifRuleOrph (mi_rules new_iface),
413 mi_decls = [(initialVersion, decl) | decl <- new_decls],
414 mi_ver_fn = \n -> Just initialVersion },
416 ptext SLIT("No old interface file"),
417 pprOrphans orph_insts orph_rules)
419 orph_insts = filter (isNothing . ifInstOrph) (mi_insts new_iface)
420 orph_rules = filter (isNothing . ifRuleOrph) (mi_rules new_iface)
422 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
423 mi_exp_vers = old_exp_vers,
424 mi_rule_vers = old_rule_vers,
425 mi_decls = old_decls,
426 mi_ver_fn = old_decl_vers,
427 mi_fix_fn = old_fixities }))
428 new_iface@(ModIface { mi_fix_fn = new_fixities })
431 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged"), pp_orphs)
432 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
433 nest 2 pp_diffs], pp_orphs)
435 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
436 mi_exp_vers = bump_unless no_export_change old_exp_vers,
437 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
438 mi_orphan = not (null new_orph_rules && null new_orph_insts),
439 mi_decls = decls_w_vers,
440 mi_ver_fn = mkIfaceVerCache decls_w_vers }
442 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
445 (old_non_orph_insts, old_orph_insts) = mkOrphMap ifInstOrph (mi_insts old_iface)
446 (new_non_orph_insts, new_orph_insts) = mkOrphMap ifInstOrph (mi_insts new_iface)
447 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
448 (lookupOccEnv old_non_orph_insts occ)
449 (lookupOccEnv new_non_orph_insts occ)
451 (old_non_orph_rules, old_orph_rules) = mkOrphMap ifRuleOrph (mi_rules old_iface)
452 (new_non_orph_rules, new_orph_rules) = mkOrphMap ifRuleOrph (mi_rules new_iface)
453 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
454 (lookupOccEnv old_non_orph_rules occ)
455 (lookupOccEnv new_non_orph_rules occ)
457 -- Computing what changed
458 no_output_change = no_decl_change && no_rule_change &&
459 no_export_change && no_deprec_change
460 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
461 no_decl_change = isEmptyOccSet changed_occs
462 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
463 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
464 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
466 -- If the usages havn't changed either, we don't need to write the interface file
467 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
468 mi_deps new_iface == mi_deps old_iface
469 no_change_at_all = no_output_change && no_other_changes
471 pp_diffs = vcat [pp_change no_export_change "Export list"
472 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
473 pp_change no_rule_change "Rules"
474 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
475 pp_change no_deprec_change "Deprecations" empty,
476 pp_change no_other_changes "Usages" empty,
478 pp_change True what info = empty
479 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
482 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
483 same_fixity n = bool (old_fixities n == new_fixities n)
486 -- Adding version info
487 new_version = bumpVersion old_mod_vers
488 add_vers decl | occ `elemOccSet` changed_occs = new_version
489 | otherwise = expectJust "add_vers" (old_decl_vers occ)
490 -- If it's unchanged, there jolly well
491 where -- should be an old version number
495 changed_occs :: OccSet
496 changed_occs = computeChangedOccs eq_info
498 eq_info :: [(OccName, IfaceEq)]
499 eq_info = map check_eq new_decls
500 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
501 = (occ, new_decl `eqIfDecl` old_decl &&&
502 eq_indirects new_decl)
503 | otherwise {- No corresponding old decl -}
506 occ = ifName new_decl
508 eq_indirects :: IfaceDecl -> IfaceEq
509 -- When seeing if two decls are the same, remember to
510 -- check whether any relevant fixity or rules have changed
511 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
512 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
513 = same_insts cls_occ &&&
514 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
515 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
516 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
517 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
518 eq_indirects other = Equal -- Synonyms and foreign declarations
520 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
521 eq_ind_occ occ = same_fixity occ &&& same_rules occ
522 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
526 pp_decl_diffs :: SDoc -- Nothing => no changes
528 | isEmptyOccSet changed_occs = empty
530 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
531 ptext SLIT("Version change for these decls:"),
532 nest 2 (vcat (map show_change new_decls))]
534 eq_env = mkOccEnv eq_info
536 | not (occ `elemOccSet` changed_occs) = empty
538 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
541 occ = ifName new_decl
542 why = case lookupOccEnv eq_env occ of
543 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
544 nest 2 (braces (fsep (map ppr (occSetElts
545 (occs `intersectOccSet` changed_occs)))))]
547 | Just old_decl <- lookupOccEnv old_decl_env occ
548 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
549 ptext SLIT("New:") <+> ppr new_decl]
551 -> ppr occ <+> ptext SLIT("only in new interface")
552 other -> pprPanic "MkIface.show_change" (ppr occ)
554 pp_orphs = pprOrphans new_orph_insts new_orph_rules
556 pprOrphans insts rules
557 | null insts && null rules = Nothing
560 if null insts then empty else
561 hang (ptext SLIT("Warning: orphan instances:"))
562 2 (vcat (map ppr insts)),
563 if null rules then empty else
564 hang (ptext SLIT("Warning: orphan rules:"))
565 2 (vcat (map ppr rules))
568 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
569 computeChangedOccs eq_info
570 = foldl add_changes emptyOccSet (stronglyConnComp edges)
572 edges :: [((OccName,IfaceEq), Unique, [Unique])]
573 edges = [ (node, getUnique occ, map getUnique occs)
574 | node@(occ, iface_eq) <- eq_info
575 , let occs = case iface_eq of
576 EqBut occ_set -> occSetElts occ_set
579 -- Changes in declarations
580 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
581 add_changes so_far (AcyclicSCC (occ, iface_eq))
582 | changedWrt so_far iface_eq -- This one has changed
583 = extendOccSet so_far occ
584 add_changes so_far (CyclicSCC pairs)
585 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
586 = extendOccSetList so_far (map fst pairs)
587 add_changes so_far other = so_far
589 changedWrt :: OccSet -> IfaceEq -> Bool
590 changedWrt so_far Equal = False
591 changedWrt so_far NotEqual = True
592 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
594 ----------------------
595 -- mkOrphMap partitions instance decls or rules into
596 -- (a) an OccEnv for ones that are not orphans,
597 -- mapping the local OccName to a list of its decls
598 -- (b) a list of orphan decls
599 mkOrphMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
600 -- Nothing for an orphan decl
601 -> [decl] -- Sorted into canonical order
602 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
603 -- each sublist in canonical order
604 [decl]) -- Orphan decls; in canonical order
605 mkOrphMap get_key decls
606 = foldl go (emptyOccEnv, []) decls
608 go (non_orphs, orphs) d
609 | Just occ <- get_key d
610 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
611 | otherwise = (non_orphs, d:orphs)
613 anyNothing :: (a -> Maybe b) -> [a] -> Bool
614 anyNothing p [] = False
615 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
617 ----------------------
618 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
619 mkIfaceDeprec NoDeprecs = NoDeprecs
620 mkIfaceDeprec (DeprecAll t) = DeprecAll t
621 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
623 ----------------------
624 bump_unless :: Bool -> Version -> Version
625 bump_unless True v = v -- True <=> no change
626 bump_unless False v = bumpVersion v
630 %*********************************************************
632 \subsection{Keeping track of what we've slurped, and version numbers}
634 %*********************************************************
638 mkUsageInfo :: HscEnv
639 -> ModuleEnv (Module, Maybe Bool, SrcSpan)
640 -> [(Module, IsBootInterface)]
641 -> NameSet -> IO [Usage]
642 mkUsageInfo hsc_env dir_imp_mods dep_mods used_names
643 = do { eps <- hscEPS hsc_env
644 ; let usages = mk_usage_info (eps_PIT eps) hsc_env
645 dir_imp_mods dep_mods used_names
646 ; usages `seqList` return usages }
647 -- seq the list of Usages returned: occasionally these
648 -- don't get evaluated for a while and we can end up hanging on to
649 -- the entire collection of Ifaces.
651 mk_usage_info pit hsc_env dir_imp_mods dep_mods proto_used_names
652 = mapCatMaybes mkUsage dep_mods
653 -- ToDo: do we need to sort into canonical order?
655 dflags = hsc_dflags hsc_env
656 hpt = hsc_HPT hsc_env
658 used_names = mkNameSet $ -- Eliminate duplicates
659 [ nameParent n -- Just record usage on the 'main' names
660 | n <- nameSetToList proto_used_names
661 , not (isWiredInName n) -- Don't record usages for wired-in names
662 , isExternalName n -- Ignore internal names
665 -- ent_map groups together all the things imported and used
666 -- from a particular module in this package
667 ent_map :: ModuleEnv [OccName]
668 ent_map = foldNameSet add_mv emptyModuleEnv used_names
669 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
671 occ = nameOccName name
672 mod = nameModule name
673 add_item occs _ = occ:occs
675 import_all mod = case lookupModuleEnv dir_imp_mods mod of
676 Just (_,imp_all,_) -> isNothing imp_all
679 -- We want to create a Usage for a home module if
680 -- a) we used something from; has something in used_names
681 -- b) we imported all of it, even if we used nothing from it
682 -- (need to recompile if its export list changes: export_vers)
683 -- c) is a home-package orphan module (need to recompile if its
684 -- instance decls change: rules_vers)
685 mkUsage :: (Module, Bool) -> Maybe Usage
686 mkUsage (mod_name, _)
687 | isNothing maybe_iface -- We can't depend on it if we didn't
688 || not (isHomeModule dflags mod) -- even open the interface!
692 = Nothing -- Record no usage info
695 = Just (Usage { usg_name = mod,
697 usg_exports = export_vers,
698 usg_entities = ent_vers,
699 usg_rules = rules_vers })
701 maybe_iface = lookupIfaceByModule hpt pit mod_name
702 -- In one-shot mode, the interfaces for home-package
703 -- modules accumulate in the PIT not HPT. Sigh.
705 Just iface = maybe_iface
706 mod = mi_module iface
707 orphan_mod = mi_orphan iface
708 version_env = mi_ver_fn iface
709 mod_vers = mi_mod_vers iface
710 rules_vers = mi_rule_vers iface
711 all_imported = import_all mod
712 export_vers | all_imported = Just (mi_exp_vers iface)
713 | otherwise = Nothing
715 -- The sort is to put them into canonical order
716 used_occs = lookupModuleEnv ent_map mod `orElse` []
717 ent_vers :: [(OccName,Version)]
718 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
719 | occ <- sortLe (<=) used_occs]
723 mkIfaceExports :: NameSet -> [(Module, [GenAvailInfo OccName])]
724 -- Group by module and sort by occurrence
725 -- This keeps the list in canonical order
726 mkIfaceExports exports
727 = [ (mkSysModuleFS fs, eltsFM avails)
728 | (fs, avails) <- fmToList groupFM
731 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
732 -- Deliberately use the FastString so we
733 -- get a canonical ordering
734 groupFM = foldl add emptyFM (nameSetToList exports)
736 add env name = addToFM_C add_avail env mod_fs
737 (unitFM avail_fs avail)
739 occ = nameOccName name
740 mod_fs = moduleFS (nameModule name)
741 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
742 | isTcOcc occ = AvailTC occ [occ]
743 | otherwise = Avail occ
744 avail_fs = occNameFS (availName avail)
745 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
747 add_item (AvailTC p occs) _ = AvailTC p (List.insert occ occs)
748 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
752 %************************************************************************
754 Load the old interface file for this module (unless
755 we have it aleady), and check whether it is up to date
758 %************************************************************************
761 checkOldIface :: HscEnv
763 -> Bool -- Source unchanged
764 -> Maybe ModIface -- Old interface from compilation manager, if any
765 -> IO (RecompileRequired, Maybe ModIface)
767 checkOldIface hsc_env mod_summary source_unchanged maybe_iface
768 = do { showPass (hsc_dflags hsc_env)
769 ("Checking old interface for " ++ moduleUserString (ms_mod mod_summary)) ;
771 ; initIfaceCheck hsc_env $
772 check_old_iface mod_summary source_unchanged maybe_iface
775 check_old_iface mod_summary source_unchanged maybe_iface
776 = -- CHECK WHETHER THE SOURCE HAS CHANGED
777 ifM (not source_unchanged)
778 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
781 -- If the source has changed and we're in interactive mode, avoid reading
782 -- an interface; just return the one we might have been supplied with.
783 getGhciMode `thenM` \ ghci_mode ->
784 if (ghci_mode == Interactive) && not source_unchanged then
785 returnM (outOfDate, maybe_iface)
788 case maybe_iface of {
789 Just old_iface -> -- Use the one we already have
790 checkVersions source_unchanged old_iface `thenM` \ recomp ->
791 returnM (recomp, Just old_iface)
795 -- Try and read the old interface for the current module
796 -- from the .hi file left from the last time we compiled it
798 iface_path = msHiFilePath mod_summary
800 readIface (ms_mod mod_summary) iface_path False `thenM` \ read_result ->
801 case read_result of {
802 Failed err -> -- Old interface file not found, or garbled; give up
803 traceIf (text "FYI: cannot read old interface file:"
804 $$ nest 4 err) `thenM_`
805 returnM (outOfDate, Nothing)
809 -- We have got the old iface; check its versions
810 checkVersions source_unchanged iface `thenM` \ recomp ->
811 returnM (recomp, Just iface)
815 @recompileRequired@ is called from the HscMain. It checks whether
816 a recompilation is required. It needs access to the persistent state,
817 finder, etc, because it may have to load lots of interface files to
818 check their versions.
821 type RecompileRequired = Bool
822 upToDate = False -- Recompile not required
823 outOfDate = True -- Recompile required
825 checkVersions :: Bool -- True <=> source unchanged
826 -> ModIface -- Old interface
827 -> IfG RecompileRequired
828 checkVersions source_unchanged iface
829 | not source_unchanged
832 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
833 ppr (mi_module iface) <> colon)
835 -- Source code unchanged and no errors yet... carry on
837 -- First put the dependent-module info, read from the old interface, into the envt,
838 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
840 -- It's just temporary because either the usage check will succeed
841 -- (in which case we are done with this module) or it'll fail (in which
842 -- case we'll compile the module from scratch anyhow).
844 -- We do this regardless of compilation mode
845 ; updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
847 ; checkList [checkModUsage u | u <- mi_usages iface]
850 -- This is a bit of a hack really
851 mod_deps :: ModuleEnv (Module, IsBootInterface)
852 mod_deps = mkModDeps (dep_mods (mi_deps iface))
854 checkModUsage :: Usage -> IfG RecompileRequired
855 -- Given the usage information extracted from the old
856 -- M.hi file for the module being compiled, figure out
857 -- whether M needs to be recompiled.
859 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
860 usg_rules = old_rule_vers,
861 usg_exports = maybe_old_export_vers,
862 usg_entities = old_decl_vers })
863 = -- Load the imported interface is possible
865 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
867 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
869 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
870 -- Load the interface, but don't complain on failure;
871 -- Instead, get an Either back which we can test
874 Failed exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
876 -- Couldn't find or parse a module mentioned in the
877 -- old interface file. Don't complain -- it might just be that
878 -- the current module doesn't need that import and it's been deleted
882 new_mod_vers = mi_mod_vers iface
883 new_decl_vers = mi_ver_fn iface
884 new_export_vers = mi_exp_vers iface
885 new_rule_vers = mi_rule_vers iface
888 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
889 if not recompile then
894 if checkExportList maybe_old_export_vers new_export_vers then
895 out_of_date_vers (ptext SLIT(" Export list changed"))
896 (fromJust maybe_old_export_vers)
901 if old_rule_vers /= new_rule_vers then
902 out_of_date_vers (ptext SLIT(" Rules changed"))
903 old_rule_vers new_rule_vers
906 -- CHECK ITEMS ONE BY ONE
907 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
909 returnM outOfDate -- This one failed, so just bail out now
911 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
914 ------------------------
915 checkModuleVersion old_mod_vers new_mod_vers
916 | new_mod_vers == old_mod_vers
917 = up_to_date (ptext SLIT("Module version unchanged"))
920 = out_of_date_vers (ptext SLIT(" Module version has changed"))
921 old_mod_vers new_mod_vers
923 ------------------------
924 checkExportList Nothing new_vers = upToDate
925 checkExportList (Just v) new_vers = v /= new_vers
927 ------------------------
928 checkEntityUsage new_vers (name,old_vers)
929 = case new_vers name of
931 Nothing -> -- We used it before, but it ain't there now
932 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
934 Just new_vers -- It's there, but is it up to date?
935 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
937 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
940 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
941 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
942 out_of_date_vers msg old_vers new_vers
943 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
945 ----------------------
946 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
947 -- This helper is used in two places
948 checkList [] = returnM upToDate
949 checkList (check:checks) = check `thenM` \ recompile ->
956 %************************************************************************
960 %************************************************************************
963 showIface :: FilePath -> IO ()
964 -- Read binary interface, and print it out
965 showIface filename = do
966 -- skip the version check; we don't want to worry about profiled vs.
967 -- non-profiled interfaces, for example.
968 writeIORef v_IgnoreHiWay True
969 iface <- Binary.getBinFileWithDict filename
970 printDump (pprModIface iface)
976 pprModIface :: ModIface -> SDoc
979 = vcat [ ptext SLIT("interface")
980 <+> ppr_package (mi_package iface)
981 <+> ppr (mi_module iface) <+> pp_boot
982 <+> ppr (mi_mod_vers iface) <+> pp_sub_vers
983 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
984 <+> int opt_HiVersion
985 <+> ptext SLIT("where")
986 , vcat (map pprExport (mi_exports iface))
987 , pprDeps (mi_deps iface)
988 , vcat (map pprUsage (mi_usages iface))
989 , pprFixities (mi_fixities iface)
990 , vcat (map pprIfaceDecl (mi_decls iface))
991 , vcat (map ppr (mi_insts iface))
992 , vcat (map ppr (mi_rules iface))
993 , pprDeprecs (mi_deprecs iface)
996 pp_boot | mi_boot iface = ptext SLIT("[boot]")
998 ppr_package HomePackage = empty
999 ppr_package (ExtPackage id) = doubleQuotes (ppr id)
1001 exp_vers = mi_exp_vers iface
1002 rule_vers = mi_rule_vers iface
1004 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1005 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1008 When printing export lists, we print like this:
1010 AvailTC C [C, x, y] C(x,y)
1011 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1014 pprExport :: IfaceExport -> SDoc
1015 pprExport (mod, items)
1016 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1018 pp_avail :: GenAvailInfo OccName -> SDoc
1019 pp_avail (Avail occ) = ppr occ
1020 pp_avail (AvailTC _ []) = empty
1021 pp_avail (AvailTC n (n':ns))
1022 | n==n' = ppr n <> pp_export ns
1023 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1025 pp_export [] = empty
1026 pp_export names = braces (hsep (map ppr names))
1028 pprUsage :: Usage -> SDoc
1030 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1031 int (usg_mod usage),
1032 pp_export_version (usg_exports usage),
1033 int (usg_rules usage),
1034 pp_versions (usg_entities usage) ]
1036 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1037 pp_export_version Nothing = empty
1038 pp_export_version (Just v) = int v
1040 pprDeps :: Dependencies -> SDoc
1041 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1042 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1043 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1044 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1047 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1048 ppr_boot True = text "[boot]"
1049 ppr_boot False = empty
1051 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1052 pprIfaceDecl (ver, decl)
1053 = ppr_vers ver <+> ppr decl
1055 -- Print the version for the decl
1056 ppr_vers v | v == initialVersion = empty
1059 pprFixities :: [(OccName, Fixity)] -> SDoc
1060 pprFixities [] = empty
1061 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1063 pprFix (occ,fix) = ppr fix <+> ppr occ
1065 pprDeprecs NoDeprecs = empty
1066 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1067 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1069 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)