2 % (c) The GRASP/AQUA Project, Glasgow University, 1993-1998
7 showIface, -- Print the iface in Foo.hi
9 mkUsageInfo, -- Construct the usage info for a module
11 mkIface, -- Build a ModIface from a ModGuts,
12 -- including computing version information
14 checkOldIface -- See if recompilation is required, by
15 -- comparing version information
19 -----------------------------------------------
20 MkIface.lhs deals with versioning
21 -----------------------------------------------
23 Here's the version-related info in an interface file
25 module Foo 8 -- module-version
26 3 -- export-list-version
28 Usages: -- Version info for what this compilation of Foo imported
29 Baz 3 -- Module version
30 [4] -- The export-list version if Foo depended on it
31 (g,2) -- Function and its version
32 (T,1) -- Type and its version
34 <version> f :: Int -> Int {- Unfolding: \x -> Wib.t[2] x -}
35 -- The [2] says that f's unfolding
36 -- mentions verison 2 of Wib.t
38 -----------------------------------------------
40 -----------------------------------------------
43 * In the mi_usages information in an interface, we record the
44 version number of each free variable of the module
46 * In mkIface, we compute the version number of each exported thing A.f
47 by comparing its A.f's info with its new info, and bumping its
48 version number if it differs. If A.f mentions B.g, and B.g's version
49 number has changed, then we count A.f as having changed too.
51 * In checkOldIface we compare the mi_usages for the module with
52 the actual version info for all each thing recorded in mi_usages
57 We count A.f as changing if its fixity changes
61 If a rule changes, we want to recompile any module that might be
62 affected by that rule. For non-orphan rules, this is relatively easy.
63 If module M defines f, and a rule for f, just arrange that the version
64 number for M.f changes if any of the rules for M.f change. Any module
65 that does not depend on M.f can't be affected by the rule-change
68 Orphan rules (ones whose 'head function' is not defined in M) are
69 harder. Here's what we do.
71 * We have a per-module orphan-rule version number which changes if
72 any orphan rule changes. (It's unaffected by non-orphan rules.)
74 * We record usage info for any orphan module 'below' this one,
75 giving the orphan-rule version number. We recompile if this
78 The net effect is that if an orphan rule changes, we recompile every
79 module above it. That's very conservative, but it's devilishly hard
80 to know what it might affect, so we just have to be conservative.
84 In an iface file we have
86 instance Eq a => Eq [a] = dfun29
89 We have a version number for dfun29, covering its unfolding
90 etc. Suppose we are compiling a module M that imports A only
91 indirectly. If typechecking M uses this instance decl, we record the
92 dependency on A.dfun29 as if it were a free variable of the module
93 (via the tcg_inst_usages accumulator). That means that A will appear
94 in M's usage list. If the shape of the instance declaration changes,
95 then so will dfun29's version, triggering a recompilation.
97 Adding an instance declaration, or changing an instance decl that is
98 not currently used, is more tricky. (This really only makes a
99 difference when we have overlapping instance decls, because then the
100 new instance decl might kick in to override the old one.) We handle
101 this in a very similar way that we handle rules above.
103 * For non-orphan instance decls, identify one locally-defined tycon/class
104 mentioned in the decl. Treat the instance decl as part of the defn of that
105 tycon/class, so that if the shape of the instance decl changes, so does the
106 tycon/class; that in turn will force recompilation of anything that uses
109 * For orphan instance decls, act the same way as for orphan rules.
110 Indeed, we use the same global orphan-rule version number.
114 mkUsageInfo figures out what the ``usage information'' for this
115 moudule is; that is, what it must record in its interface file as the
118 We produce a line for every module B below the module, A, currently being
121 to record the fact that A does import B indirectly. This is used to decide
122 to look to look for B.hi rather than B.hi-boot when compiling a module that
123 imports A. This line says that A imports B, but uses nothing in it.
124 So we'll get an early bale-out when compiling A if B's version changes.
126 The usage information records:
129 \item (a) anything reachable from its body code
130 \item (b) any module exported with a @module Foo@
131 \item (c) anything reachable from an exported item
134 Why (b)? Because if @Foo@ changes then this module's export list
135 will change, so we must recompile this module at least as far as
136 making a new interface file --- but in practice that means complete
139 Why (c)? Consider this:
141 module A( f, g ) where | module B( f ) where
142 import B( f ) | f = h 3
146 Here, @B.f@ isn't used in A. Should we nevertheless record @B.f@ in
147 @A@'s usages? Our idea is that we aren't going to touch A.hi if it is
148 *identical* to what it was before. If anything about @B.f@ changes
149 than anyone who imports @A@ should be recompiled in case they use
150 @B.f@ (they'll get an early exit if they don't). So, if anything
151 about @B.f@ changes we'd better make sure that something in A.hi
152 changes, and the convenient way to do that is to record the version
153 number @B.f@ in A.hi in the usage list. If B.f changes that'll force a
154 complete recompiation of A, which is overkill but it's the only way to
155 write a new, slightly different, A.hi.
157 But the example is tricker. Even if @B.f@ doesn't change at all,
158 @B.h@ may do so, and this change may not be reflected in @f@'s version
159 number. But with -O, a module that imports A must be recompiled if
160 @B.h@ changes! So A must record a dependency on @B.h@. So we treat
161 the occurrence of @B.f@ in the export list *just as if* it were in the
162 code of A, and thereby haul in all the stuff reachable from it.
164 *** Conclusion: if A mentions B.f in its export list,
165 behave just as if A mentioned B.f in its source code,
166 and slurp in B.f and all its transitive closure ***
168 [NB: If B was compiled with -O, but A isn't, we should really *still*
169 haul in all the unfoldings for B, in case the module that imports A *is*
170 compiled with -O. I think this is the case.]
174 #include "HsVersions.h"
177 import Packages ( isHomeModule )
178 import IfaceSyn ( IfaceDecl(..), IfaceClassOp(..), IfaceConDecl(..),
179 IfaceRule(..), IfaceInst(..), IfaceExtName(..), IfaceTyCon(..),
180 eqIfDecl, eqIfRule, eqIfInst, IfaceEq(..), (&&&), bool,
181 eqMaybeBy, eqListBy, visibleIfConDecls,
182 tyThingToIfaceDecl, dfunToIfaceInst, coreRuleToIfaceRule )
183 import LoadIface ( readIface, loadInterface, ifaceInstGates )
184 import BasicTypes ( Version, initialVersion, bumpVersion )
186 import TcRnTypes ( mkModDeps )
187 import TcType ( isFFITy )
188 import HscTypes ( ModIface(..), TyThing(..), IfacePackage(..),
189 ModGuts(..), ModGuts, IfaceExport,
190 GhciMode(..), HscEnv(..), hscEPS,
191 Dependencies(..), FixItem(..),
192 mkIfaceDepCache, mkIfaceFixCache, mkIfaceVerCache,
194 GenAvailInfo(..), availName,
195 ExternalPackageState(..),
196 Usage(..), IsBootInterface,
197 Deprecs(..), IfaceDeprecs, Deprecations,
203 import Name ( Name, nameModule, nameOccName, nameParent,
204 isExternalName, nameParent_maybe, isWiredInName,
208 import OccName ( OccName, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv,
210 OccSet, emptyOccSet, elemOccSet, occSetElts,
211 extendOccSet, extendOccSetList,
212 isEmptyOccSet, intersectOccSet, intersectsOccSet,
214 import TyCon ( tyConDataCons, isNewTyCon, newTyConRep )
215 import Class ( classSelIds )
216 import DataCon ( dataConName, dataConFieldLabels )
217 import Module ( Module, moduleFS,
218 ModLocation(..), mkSysModuleFS, moduleUserString,
219 ModuleEnv, emptyModuleEnv, lookupModuleEnv,
223 import DriverUtil ( createDirectoryHierarchy, directoryOf )
224 import Util ( sortLe, seqList )
225 import Binary ( getBinFileWithDict )
226 import BinIface ( writeBinIface, v_IgnoreHiWay )
227 import Unique ( Unique, Uniquable(..) )
228 import ErrUtils ( dumpIfSet_dyn, showPass )
229 import Digraph ( stronglyConnComp, SCC(..) )
230 import SrcLoc ( SrcSpan )
234 import DATA_IOREF ( writeIORef )
235 import Monad ( when )
236 import List ( insert )
237 import Maybes ( orElse, mapCatMaybes, isNothing, isJust, fromJust, expectJust )
242 %************************************************************************
244 \subsection{Completing an interface}
246 %************************************************************************
251 -> Maybe ModIface -- The old interface, if we have it
252 -> ModGuts -- The compiled, tidied module
253 -> IO ModIface -- The new one, complete with decls and versions
255 -- a) Builds the ModIface
256 -- b) Writes it out to a file if necessary
258 mkIface hsc_env location maybe_old_iface
259 guts@ModGuts{ mg_module = this_mod,
262 mg_exports = exports,
263 mg_fix_env = fix_env,
264 mg_deprecs = src_deprecs,
267 mg_types = type_env }
268 = do { eps <- hscEPS hsc_env
269 ; let { ext_nm = mkExtNameFn hsc_env eps this_mod
270 ; local_things = [thing | thing <- typeEnvElts type_env,
271 not (isWiredInName (getName thing)) ]
272 -- Do not export anything about wired-in things
273 -- (GHC knows about them already)
275 ; abstract_tcs :: NameSet -- TyCons and Classes whose representation is not exposed
277 | not omit_prags = emptyNameSet -- In the -O case, nothing is abstract
278 | otherwise = mkNameSet [ getName thing
279 | thing <- local_things
280 , not (mustExposeThing exports thing)]
282 ; decls = [ tyThingToIfaceDecl omit_prags abstract_tcs ext_nm thing
283 | thing <- local_things, wantDeclFor exports abstract_tcs thing ]
284 -- Don't put implicit Ids and class tycons in the interface file
286 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
287 ; deprecs = mkIfaceDeprec src_deprecs
290 | otherwise = sortLe le_rule $
291 map (coreRuleToIfaceRule this_mod ext_nm) rules
292 ; iface_insts = sortLe le_inst (map dfunToIfaceInst insts)
294 ; intermediate_iface = ModIface {
295 mi_module = this_mod,
296 mi_package = ThisPackage,
300 mi_exports = mkIfaceExports exports,
301 mi_insts = iface_insts,
302 mi_rules = iface_rules,
303 mi_fixities = fixities,
304 mi_deprecs = deprecs,
306 -- Left out deliberately: filled in by addVersionInfo
307 mi_mod_vers = initialVersion,
308 mi_exp_vers = initialVersion,
309 mi_rule_vers = initialVersion,
310 mi_orphan = False, -- Always set by addVersionInfo, but
311 -- it's a strict field, so we can't omit it.
312 mi_decls = deliberatelyOmitted "decls",
313 mi_ver_fn = deliberatelyOmitted "ver_fn",
315 -- And build the cached values
316 mi_dep_fn = mkIfaceDepCache deprecs,
317 mi_fix_fn = mkIfaceFixCache fixities }
319 -- Add version information
320 ; (new_iface, no_change_at_all, pp_diffs, pp_orphs)
321 = _scc_ "versioninfo"
322 addVersionInfo maybe_old_iface intermediate_iface decls
325 -- Write the interface file, if necessary
326 ; when (not no_change_at_all && ghci_mode /= Interactive) $ do
327 createDirectoryHierarchy (directoryOf hi_file_path)
328 writeBinIface hi_file_path new_iface
331 ; when (isJust pp_orphs && dopt Opt_WarnOrphans dflags)
332 (printDump (fromJust pp_orphs))
333 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
334 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
335 (pprModIface new_iface)
339 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
340 i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
342 dflags = hsc_dflags hsc_env
343 ghci_mode = hsc_mode hsc_env
344 hi_file_path = ml_hi_file location
345 omit_prags = dopt Opt_OmitInterfacePragmas dflags
348 mustExposeThing :: NameSet -> TyThing -> Bool
349 -- We are compiling without -O, and thus trying to write as little as
350 -- possible into the interface file. But we must expose the details of
351 -- any data types and classes whose constructors, fields, methods are
352 -- visible to an importing module
353 mustExposeThing exports (ATyCon tc)
354 = any exported_data_con (tyConDataCons tc)
355 -- Expose rep if any datacon or field is exported
357 || (isNewTyCon tc && isFFITy (snd (newTyConRep tc)))
358 -- Expose the rep for newtypes if the rep is an FFI type.
359 -- For a very annoying reason. 'Foreign import' is meant to
360 -- be able to look through newtypes transparently, but it
361 -- can only do that if it can "see" the newtype representation
363 exported_data_con con
364 = any (`elemNameSet` exports) (dataConName con : dataConFieldLabels con)
366 mustExposeThing exports (AClass cls)
367 = any exported_class_op (classSelIds cls)
368 where -- Expose rep if any classs op is exported
369 exported_class_op op = getName op `elemNameSet` exports
371 mustExposeThing exports other = False
374 wantDeclFor :: NameSet -- User-exported things
375 -> NameSet -- Abstract things
377 wantDeclFor exports abstracts thing
378 | Just parent <- nameParent_maybe name -- An implicit thing
379 = parent `elemNameSet` abstracts && name `elemNameSet` exports
386 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
388 -----------------------------
389 mkExtNameFn :: HscEnv -> ExternalPackageState -> Module -> Name -> IfaceExtName
390 mkExtNameFn hsc_env eps this_mod
393 dflags = hsc_dflags hsc_env
394 hpt = hsc_HPT hsc_env
398 | mod == this_mod = case nameParent_maybe name of
399 Nothing -> LocalTop occ
400 Just par -> LocalTopSub occ (nameOccName par)
401 | isWiredInName name = ExtPkg mod occ
402 | isHomeModule dflags mod = HomePkg mod occ vers
403 | otherwise = ExtPkg mod occ
405 mod = nameModule name
406 occ = nameOccName name
407 par_occ = nameOccName (nameParent name)
408 -- The version of the *parent* is the one want
409 vers = lookupVersion mod par_occ
411 lookupVersion :: Module -> OccName -> Version
412 -- Even though we're looking up a home-package thing, in
413 -- one-shot mode the imported interfaces may be in the PIT
414 lookupVersion mod occ
415 = mi_ver_fn iface occ `orElse`
416 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
418 iface = lookupIfaceByModule hpt pit mod `orElse`
419 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
421 -----------------------------
422 -- Compute version numbers for local decls
424 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
425 -> ModIface -- The new interface decls (lacking decls)
426 -> [IfaceDecl] -- The new decls
428 Bool, -- True <=> no changes at all; no need to write new Iface
430 Maybe SDoc) -- Warnings about orphans
432 addVersionInfo Nothing new_iface new_decls
433 -- No old interface, so definitely write a new one!
434 = (new_iface { mi_orphan = anyNothing getInstKey (mi_insts new_iface)
435 || anyNothing getRuleKey (mi_rules new_iface),
436 mi_decls = [(initialVersion, decl) | decl <- new_decls],
437 mi_ver_fn = \n -> Just initialVersion },
439 ptext SLIT("No old interface file"),
440 pprOrphans orph_insts orph_rules)
442 orph_insts = filter (isNothing . getInstKey) (mi_insts new_iface)
443 orph_rules = filter (isNothing . getRuleKey) (mi_rules new_iface)
445 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
446 mi_exp_vers = old_exp_vers,
447 mi_rule_vers = old_rule_vers,
448 mi_decls = old_decls,
449 mi_ver_fn = old_decl_vers,
450 mi_fix_fn = old_fixities }))
451 new_iface@(ModIface { mi_fix_fn = new_fixities })
454 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged"), pp_orphs)
455 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
456 nest 2 pp_diffs], pp_orphs)
458 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
459 mi_exp_vers = bump_unless no_export_change old_exp_vers,
460 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
461 mi_orphan = not (null new_orph_rules && null new_orph_insts),
462 mi_decls = decls_w_vers,
463 mi_ver_fn = mkIfaceVerCache decls_w_vers }
465 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
468 (old_non_orph_insts, old_orph_insts) = mkRuleMap getInstKey (mi_insts old_iface)
469 (new_non_orph_insts, new_orph_insts) = mkRuleMap getInstKey (mi_insts new_iface)
470 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
471 (lookupOccEnv old_non_orph_insts occ)
472 (lookupOccEnv new_non_orph_insts occ)
474 (old_non_orph_rules, old_orph_rules) = mkRuleMap getRuleKey (mi_rules old_iface)
475 (new_non_orph_rules, new_orph_rules) = mkRuleMap getRuleKey (mi_rules new_iface)
476 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
477 (lookupOccEnv old_non_orph_rules occ)
478 (lookupOccEnv new_non_orph_rules occ)
480 -- Computing what changed
481 no_output_change = no_decl_change && no_rule_change &&
482 no_export_change && no_deprec_change
483 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
484 no_decl_change = isEmptyOccSet changed_occs
485 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
486 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
487 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
489 -- If the usages havn't changed either, we don't need to write the interface file
490 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
491 mi_deps new_iface == mi_deps old_iface
492 no_change_at_all = no_output_change && no_other_changes
494 pp_diffs = vcat [pp_change no_export_change "Export list"
495 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
496 pp_change no_rule_change "Rules"
497 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
498 pp_change no_deprec_change "Deprecations" empty,
499 pp_change no_other_changes "Usages" empty,
501 pp_change True what info = empty
502 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
505 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
506 same_fixity n = bool (old_fixities n == new_fixities n)
509 -- Adding version info
510 new_version = bumpVersion old_mod_vers
511 add_vers decl | occ `elemOccSet` changed_occs = new_version
512 | otherwise = expectJust "add_vers" (old_decl_vers occ)
513 -- If it's unchanged, there jolly well
514 where -- should be an old version number
518 changed_occs :: OccSet
519 changed_occs = computeChangedOccs eq_info
521 eq_info :: [(OccName, IfaceEq)]
522 eq_info = map check_eq new_decls
523 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
524 = (occ, new_decl `eqIfDecl` old_decl &&&
525 eq_indirects new_decl)
526 | otherwise {- No corresponding old decl -}
529 occ = ifName new_decl
531 eq_indirects :: IfaceDecl -> IfaceEq
532 -- When seeing if two decls are the same, remember to
533 -- check whether any relevant fixity or rules have changed
534 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
535 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
536 = same_insts cls_occ &&&
537 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
538 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
539 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
540 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
541 eq_indirects other = Equal -- Synonyms and foreign declarations
543 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
544 eq_ind_occ occ = same_fixity occ &&& same_rules occ
545 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
549 pp_decl_diffs :: SDoc -- Nothing => no changes
551 | isEmptyOccSet changed_occs = empty
553 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
554 ptext SLIT("Version change for these decls:"),
555 nest 2 (vcat (map show_change new_decls))]
557 eq_env = mkOccEnv eq_info
559 | not (occ `elemOccSet` changed_occs) = empty
561 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
564 occ = ifName new_decl
565 why = case lookupOccEnv eq_env occ of
566 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
567 nest 2 (braces (fsep (map ppr (occSetElts
568 (occs `intersectOccSet` changed_occs)))))]
570 | Just old_decl <- lookupOccEnv old_decl_env occ
571 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
572 ptext SLIT("New:") <+> ppr new_decl]
574 -> ppr occ <+> ptext SLIT("only in new interface")
575 other -> pprPanic "MkIface.show_change" (ppr occ)
577 pp_orphs = pprOrphans new_orph_insts new_orph_rules
579 pprOrphans insts rules
580 | null insts && null rules = Nothing
583 if null insts then empty else
584 hang (ptext SLIT("Warning: orphan instances:"))
585 2 (vcat (map ppr insts)),
586 if null rules then empty else
587 hang (ptext SLIT("Warning: orphan rules:"))
588 2 (vcat (map ppr rules))
591 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
592 computeChangedOccs eq_info
593 = foldl add_changes emptyOccSet (stronglyConnComp edges)
595 edges :: [((OccName,IfaceEq), Unique, [Unique])]
596 edges = [ (node, getUnique occ, map getUnique occs)
597 | node@(occ, iface_eq) <- eq_info
598 , let occs = case iface_eq of
599 EqBut occ_set -> occSetElts occ_set
602 -- Changes in declarations
603 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
604 add_changes so_far (AcyclicSCC (occ, iface_eq))
605 | changedWrt so_far iface_eq -- This one has changed
606 = extendOccSet so_far occ
607 add_changes so_far (CyclicSCC pairs)
608 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
609 = extendOccSetList so_far (map fst pairs)
610 add_changes so_far other = so_far
612 changedWrt :: OccSet -> IfaceEq -> Bool
613 changedWrt so_far Equal = False
614 changedWrt so_far NotEqual = True
615 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
617 ----------------------
618 -- mkRuleMap partitions instance decls or rules into
619 -- (a) an OccEnv for ones that are not orphans,
620 -- mapping the local OccName to a list of its decls
621 -- (b) a list of orphan decls
622 mkRuleMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
623 -- Nothing for an orphan decl
624 -> [decl] -- Sorted into canonical order
625 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
626 -- each sublist in canonical order
627 [decl]) -- Orphan decls; in canonical order
628 mkRuleMap get_key decls
629 = foldl go (emptyOccEnv, []) decls
631 go (non_orphs, orphs) d
632 | Just occ <- get_key d
633 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
634 | otherwise = (non_orphs, d:orphs)
636 -- getXxKey: find at least one local OccName that belongs to this decl
638 getInstKey :: IfaceInst -> Maybe OccName
639 getInstKey (IfaceInst {ifInstHead = inst_ty})
640 = case [occ | LocalTop occ <- cls_ext : tc_exts] of
644 (cls_ext, tcs) = ifaceInstGates inst_ty
645 tc_exts = [tc | IfaceTc tc <- tcs]
646 -- Ignore the wired-in IfaceTyCons; the class will do as the key
648 getRuleKey :: IfaceRule -> Maybe OccName
649 getRuleKey (IfaceRule {ifRuleHead = LocalTop occ}) = Just occ
650 getRuleKey other = Nothing
652 anyNothing :: (a -> Maybe b) -> [a] -> Bool
653 anyNothing p [] = False
654 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
656 ----------------------
657 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
658 mkIfaceDeprec NoDeprecs = NoDeprecs
659 mkIfaceDeprec (DeprecAll t) = DeprecAll t
660 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
662 ----------------------
663 bump_unless :: Bool -> Version -> Version
664 bump_unless True v = v -- True <=> no change
665 bump_unless False v = bumpVersion v
669 %*********************************************************
671 \subsection{Keeping track of what we've slurped, and version numbers}
673 %*********************************************************
677 mkUsageInfo :: HscEnv
678 -> ModuleEnv (Module, Maybe Bool, SrcSpan)
679 -> [(Module, IsBootInterface)]
680 -> NameSet -> IO [Usage]
681 mkUsageInfo hsc_env dir_imp_mods dep_mods used_names
682 = do { eps <- hscEPS hsc_env
683 ; let usages = mk_usage_info (eps_PIT eps) hsc_env
684 dir_imp_mods dep_mods used_names
685 ; usages `seqList` return usages }
686 -- seq the list of Usages returned: occasionally these
687 -- don't get evaluated for a while and we can end up hanging on to
688 -- the entire collection of Ifaces.
690 mk_usage_info pit hsc_env dir_imp_mods dep_mods proto_used_names
691 = mapCatMaybes mkUsage dep_mods
692 -- ToDo: do we need to sort into canonical order?
694 dflags = hsc_dflags hsc_env
695 hpt = hsc_HPT hsc_env
697 used_names = mkNameSet $ -- Eliminate duplicates
698 [ nameParent n -- Just record usage on the 'main' names
699 | n <- nameSetToList proto_used_names
700 , not (isWiredInName n) -- Don't record usages for wired-in names
701 , isExternalName n -- Ignore internal names
704 -- ent_map groups together all the things imported and used
705 -- from a particular module in this package
706 ent_map :: ModuleEnv [OccName]
707 ent_map = foldNameSet add_mv emptyModuleEnv used_names
708 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
710 occ = nameOccName name
711 mod = nameModule name
712 add_item occs _ = occ:occs
714 import_all mod = case lookupModuleEnv dir_imp_mods mod of
715 Just (_,imp_all,_) -> isNothing imp_all
718 -- We want to create a Usage for a home module if
719 -- a) we used something from; has something in used_names
720 -- b) we imported all of it, even if we used nothing from it
721 -- (need to recompile if its export list changes: export_vers)
722 -- c) is a home-package orphan module (need to recompile if its
723 -- instance decls change: rules_vers)
724 mkUsage :: (Module, Bool) -> Maybe Usage
725 mkUsage (mod_name, _)
726 | isNothing maybe_iface -- We can't depend on it if we didn't
727 || not (isHomeModule dflags mod) -- even open the interface!
731 = Nothing -- Record no usage info
734 = Just (Usage { usg_name = mod,
736 usg_exports = export_vers,
737 usg_entities = ent_vers,
738 usg_rules = rules_vers })
740 maybe_iface = lookupIfaceByModule hpt pit mod_name
741 -- In one-shot mode, the interfaces for home-package
742 -- modules accumulate in the PIT not HPT. Sigh.
744 Just iface = maybe_iface
745 mod = mi_module iface
746 orphan_mod = mi_orphan iface
747 version_env = mi_ver_fn iface
748 mod_vers = mi_mod_vers iface
749 rules_vers = mi_rule_vers iface
750 all_imported = import_all mod
751 export_vers | all_imported = Just (mi_exp_vers iface)
752 | otherwise = Nothing
754 -- The sort is to put them into canonical order
755 used_occs = lookupModuleEnv ent_map mod `orElse` []
756 ent_vers :: [(OccName,Version)]
757 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
758 | occ <- sortLe (<=) used_occs]
762 mkIfaceExports :: NameSet -> [(Module, [GenAvailInfo OccName])]
763 -- Group by module and sort by occurrence
764 -- This keeps the list in canonical order
765 mkIfaceExports exports
766 = [ (mkSysModuleFS fs, eltsFM avails)
767 | (fs, avails) <- fmToList groupFM
770 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
771 -- Deliberately use the FastString so we
772 -- get a canonical ordering
773 groupFM = foldl add emptyFM (nameSetToList exports)
775 add env name = addToFM_C add_avail env mod_fs
776 (unitFM avail_fs avail)
778 occ = nameOccName name
779 mod_fs = moduleFS (nameModule name)
780 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
781 | isTcOcc occ = AvailTC occ [occ]
782 | otherwise = Avail occ
783 avail_fs = occNameFS (availName avail)
784 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
786 add_item (AvailTC p occs) _ = AvailTC p (List.insert occ occs)
787 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
791 %************************************************************************
793 Load the old interface file for this module (unless
794 we have it aleady), and check whether it is up to date
797 %************************************************************************
800 checkOldIface :: HscEnv
802 -> FilePath -- Where the interface file is
803 -> Bool -- Source unchanged
804 -> Maybe ModIface -- Old interface from compilation manager, if any
805 -> IO (RecompileRequired, Maybe ModIface)
807 checkOldIface hsc_env mod iface_path source_unchanged maybe_iface
808 = do { showPass (hsc_dflags hsc_env)
809 ("Checking old interface for " ++ moduleUserString mod) ;
811 ; initIfaceCheck hsc_env $
812 check_old_iface mod iface_path source_unchanged maybe_iface
815 check_old_iface this_mod iface_path source_unchanged maybe_iface
816 = -- CHECK WHETHER THE SOURCE HAS CHANGED
817 ifM (not source_unchanged)
818 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
821 -- If the source has changed and we're in interactive mode, avoid reading
822 -- an interface; just return the one we might have been supplied with.
823 getGhciMode `thenM` \ ghci_mode ->
824 if (ghci_mode == Interactive) && not source_unchanged then
825 returnM (outOfDate, maybe_iface)
828 case maybe_iface of {
829 Just old_iface -> -- Use the one we already have
830 checkVersions source_unchanged old_iface `thenM` \ recomp ->
831 returnM (recomp, Just old_iface)
835 -- Try and read the old interface for the current module
836 -- from the .hi file left from the last time we compiled it
837 readIface this_mod iface_path False `thenM` \ read_result ->
838 case read_result of {
839 Left err -> -- Old interface file not found, or garbled; give up
840 traceIf (text "FYI: cannot read old interface file:"
841 $$ nest 4 err) `thenM_`
842 returnM (outOfDate, Nothing)
846 -- We have got the old iface; check its versions
847 checkVersions source_unchanged iface `thenM` \ recomp ->
848 returnM (recomp, Just iface)
852 @recompileRequired@ is called from the HscMain. It checks whether
853 a recompilation is required. It needs access to the persistent state,
854 finder, etc, because it may have to load lots of interface files to
855 check their versions.
858 type RecompileRequired = Bool
859 upToDate = False -- Recompile not required
860 outOfDate = True -- Recompile required
862 checkVersions :: Bool -- True <=> source unchanged
863 -> ModIface -- Old interface
864 -> IfG RecompileRequired
865 checkVersions source_unchanged iface
866 | not source_unchanged
869 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
870 ppr (mi_module iface) <> colon)
872 -- Source code unchanged and no errors yet... carry on
874 -- First put the dependent-module info, read from the old interface, into the envt,
875 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
877 -- It's just temporary because either the usage check will succeed
878 -- (in which case we are done with this module) or it'll fail (in which
879 -- case we'll compile the module from scratch anyhow).
881 -- We do this regardless of compilation mode
882 ; updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
884 ; checkList [checkModUsage u | u <- mi_usages iface]
887 -- This is a bit of a hack really
888 mod_deps :: ModuleEnv (Module, IsBootInterface)
889 mod_deps = mkModDeps (dep_mods (mi_deps iface))
891 checkModUsage :: Usage -> IfG RecompileRequired
892 -- Given the usage information extracted from the old
893 -- M.hi file for the module being compiled, figure out
894 -- whether M needs to be recompiled.
896 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
897 usg_rules = old_rule_vers,
898 usg_exports = maybe_old_export_vers,
899 usg_entities = old_decl_vers })
900 = -- Load the imported interface is possible
902 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
904 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
906 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
907 -- Load the interface, but don't complain on failure;
908 -- Instead, get an Either back which we can test
911 Left exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
913 -- Couldn't find or parse a module mentioned in the
914 -- old interface file. Don't complain -- it might just be that
915 -- the current module doesn't need that import and it's been deleted
919 new_mod_vers = mi_mod_vers iface
920 new_decl_vers = mi_ver_fn iface
921 new_export_vers = mi_exp_vers iface
922 new_rule_vers = mi_rule_vers iface
925 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
926 if not recompile then
931 if checkExportList maybe_old_export_vers new_export_vers then
932 out_of_date_vers (ptext SLIT(" Export list changed"))
933 (fromJust maybe_old_export_vers)
938 if old_rule_vers /= new_rule_vers then
939 out_of_date_vers (ptext SLIT(" Rules changed"))
940 old_rule_vers new_rule_vers
943 -- CHECK ITEMS ONE BY ONE
944 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
946 returnM outOfDate -- This one failed, so just bail out now
948 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
951 ------------------------
952 checkModuleVersion old_mod_vers new_mod_vers
953 | new_mod_vers == old_mod_vers
954 = up_to_date (ptext SLIT("Module version unchanged"))
957 = out_of_date_vers (ptext SLIT(" Module version has changed"))
958 old_mod_vers new_mod_vers
960 ------------------------
961 checkExportList Nothing new_vers = upToDate
962 checkExportList (Just v) new_vers = v /= new_vers
964 ------------------------
965 checkEntityUsage new_vers (name,old_vers)
966 = case new_vers name of
968 Nothing -> -- We used it before, but it ain't there now
969 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
971 Just new_vers -- It's there, but is it up to date?
972 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
974 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
977 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
978 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
979 out_of_date_vers msg old_vers new_vers
980 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
982 ----------------------
983 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
984 -- This helper is used in two places
985 checkList [] = returnM upToDate
986 checkList (check:checks) = check `thenM` \ recompile ->
993 %************************************************************************
997 %************************************************************************
1000 showIface :: FilePath -> IO ()
1001 -- Raad binary interface, and print it out
1002 showIface filename = do
1003 -- skip the version check; we don't want to worry about profiled vs.
1004 -- non-profiled interfaces, for example.
1005 writeIORef v_IgnoreHiWay True
1006 iface <- Binary.getBinFileWithDict filename
1007 printDump (pprModIface iface)
1013 pprModIface :: ModIface -> SDoc
1016 = vcat [ ptext SLIT("interface")
1017 <+> ppr_package (mi_package iface)
1018 <+> ppr (mi_module iface) <+> ppr (mi_mod_vers iface)
1020 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
1021 <+> int opt_HiVersion
1022 <+> ptext SLIT("where")
1023 , vcat (map pprExport (mi_exports iface))
1024 , pprDeps (mi_deps iface)
1025 , vcat (map pprUsage (mi_usages iface))
1026 , pprFixities (mi_fixities iface)
1027 , vcat (map pprIfaceDecl (mi_decls iface))
1028 , vcat (map ppr (mi_insts iface))
1029 , vcat (map ppr (mi_rules iface))
1030 , pprDeprecs (mi_deprecs iface)
1033 ppr_package ThisPackage = empty
1034 ppr_package (ExternalPackage id) = doubleQuotes (ftext id)
1036 exp_vers = mi_exp_vers iface
1037 rule_vers = mi_rule_vers iface
1039 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1040 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1043 When printing export lists, we print like this:
1045 AvailTC C [C, x, y] C(x,y)
1046 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1049 pprExport :: IfaceExport -> SDoc
1050 pprExport (mod, items)
1051 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1053 pp_avail :: GenAvailInfo OccName -> SDoc
1054 pp_avail (Avail occ) = ppr occ
1055 pp_avail (AvailTC _ []) = empty
1056 pp_avail (AvailTC n (n':ns))
1057 | n==n' = ppr n <> pp_export ns
1058 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1060 pp_export [] = empty
1061 pp_export names = braces (hsep (map ppr names))
1063 pprUsage :: Usage -> SDoc
1065 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1066 int (usg_mod usage),
1067 pp_export_version (usg_exports usage),
1068 int (usg_rules usage),
1069 pp_versions (usg_entities usage) ]
1071 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1072 pp_export_version Nothing = empty
1073 pp_export_version (Just v) = int v
1075 pprDeps :: Dependencies -> SDoc
1076 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1077 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1078 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1079 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1082 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1083 ppr_boot True = text "[boot]"
1084 ppr_boot False = empty
1086 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1087 pprIfaceDecl (ver, decl)
1088 = ppr_vers ver <+> ppr decl
1090 -- Print the version for the decl
1091 ppr_vers v | v == initialVersion = empty
1094 pprFixities :: [(OccName, Fixity)] -> SDoc
1095 pprFixities [] = empty
1096 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1098 pprFix (occ,fix) = ppr fix <+> ppr occ
1100 pprDeprecs NoDeprecs = empty
1101 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1102 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1104 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)