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 let name = getName thing,
283 not (isImplicitName name || isWiredInName name) ]
284 -- Don't put implicit Ids and class tycons in the interface file
285 -- Nor wired-in things; the compiler knows about them anyhow
287 ; fixities = [(occ,fix) | FixItem occ fix _ <- nameEnvElts fix_env]
288 ; deprecs = mkIfaceDeprec src_deprecs
289 ; iface_rules = map (coreRuleToIfaceRule ext_nm_lhs ext_nm_rhs) rules
290 ; iface_insts = map (instanceToIfaceInst ext_nm_lhs) insts
292 ; intermediate_iface = ModIface {
293 mi_module = this_mod,
294 mi_package = HomePackage,
298 mi_exports = mkIfaceExports exports,
299 mi_insts = sortLe le_inst iface_insts,
300 mi_rules = sortLe le_rule iface_rules,
301 mi_fixities = fixities,
302 mi_deprecs = deprecs,
303 mi_globals = Just rdr_env,
305 -- Left out deliberately: filled in by addVersionInfo
306 mi_mod_vers = initialVersion,
307 mi_exp_vers = initialVersion,
308 mi_rule_vers = initialVersion,
309 mi_orphan = False, -- Always set by addVersionInfo, but
310 -- it's a strict field, so we can't omit it.
311 mi_decls = deliberatelyOmitted "decls",
312 mi_ver_fn = deliberatelyOmitted "ver_fn",
314 -- And build the cached values
315 mi_dep_fn = mkIfaceDepCache deprecs,
316 mi_fix_fn = mkIfaceFixCache fixities }
318 -- Add version information
319 ; (new_iface, no_change_at_all, pp_diffs, pp_orphs)
320 = _scc_ "versioninfo"
321 addVersionInfo maybe_old_iface intermediate_iface decls
325 ; when (isJust pp_orphs && dopt Opt_WarnOrphans dflags)
326 (printDump (expectJust "mkIface" pp_orphs))
327 ; when (dopt Opt_D_dump_hi_diffs dflags) (printDump pp_diffs)
328 ; dumpIfSet_dyn dflags Opt_D_dump_hi "FINAL INTERFACE"
329 (pprModIface new_iface)
331 ; return (new_iface, no_change_at_all) }
333 r1 `le_rule` r2 = ifRuleName r1 <= ifRuleName r2
334 i1 `le_inst` i2 = ifDFun i1 <= ifDFun i2
336 dflags = hsc_dflags hsc_env
337 deliberatelyOmitted x = panic ("Deliberately omitted: " ++ x)
340 -----------------------------
341 writeIfaceFile :: ModLocation -> ModIface -> IO ()
342 writeIfaceFile location new_iface
343 = do createDirectoryHierarchy (directoryOf hi_file_path)
344 writeBinIface hi_file_path new_iface
345 where hi_file_path = ml_hi_file location
348 -----------------------------
349 mkExtNameFn :: HscEnv -> HomeModules -> ExternalPackageState -> Module -> Name -> IfaceExtName
350 mkExtNameFn hsc_env hmods eps this_mod
353 hpt = hsc_HPT hsc_env
357 | mod == this_mod = case nameParent_maybe name of
358 Nothing -> LocalTop occ
359 Just par -> LocalTopSub occ (nameOccName par)
360 | isWiredInName name = ExtPkg mod occ
361 | isHomeModule hmods mod = HomePkg mod occ vers
362 | otherwise = ExtPkg mod occ
364 mod = nameModule name
365 occ = nameOccName name
366 par_occ = nameOccName (nameParent name)
367 -- The version of the *parent* is the one want
368 vers = lookupVersion mod par_occ
370 lookupVersion :: Module -> OccName -> Version
371 -- Even though we're looking up a home-package thing, in
372 -- one-shot mode the imported interfaces may be in the PIT
373 lookupVersion mod occ
374 = mi_ver_fn iface occ `orElse`
375 pprPanic "lookupVers1" (ppr mod <+> ppr occ)
377 iface = lookupIfaceByModule hpt pit mod `orElse`
378 pprPanic "lookupVers2" (ppr mod <+> ppr occ)
381 ---------------------
382 -- mkLhsNameFn ignores versioning info altogether
383 -- It is used for the LHS of instance decls and rules, where we
384 -- there's no point in recording version info
385 mkLhsNameFn :: Module -> Name -> IfaceExtName
386 mkLhsNameFn this_mod name
387 | isInternalName name = pprTrace "mkLhsNameFn: unexpected internal" (ppr name) $
388 LocalTop occ -- Should not happen
389 | mod == this_mod = LocalTop occ
390 | otherwise = ExtPkg mod occ
392 mod = nameModule name
393 occ = nameOccName name
396 -----------------------------
397 -- Compute version numbers for local decls
399 addVersionInfo :: Maybe ModIface -- The old interface, read from M.hi
400 -> ModIface -- The new interface decls (lacking decls)
401 -> [IfaceDecl] -- The new decls
403 Bool, -- True <=> no changes at all; no need to write new Iface
405 Maybe SDoc) -- Warnings about orphans
407 addVersionInfo Nothing new_iface new_decls
408 -- No old interface, so definitely write a new one!
409 = (new_iface { mi_orphan = anyNothing ifInstOrph (mi_insts new_iface)
410 || anyNothing ifRuleOrph (mi_rules new_iface),
411 mi_decls = [(initialVersion, decl) | decl <- new_decls],
412 mi_ver_fn = \n -> Just initialVersion },
414 ptext SLIT("No old interface file"),
415 pprOrphans orph_insts orph_rules)
417 orph_insts = filter (isNothing . ifInstOrph) (mi_insts new_iface)
418 orph_rules = filter (isNothing . ifRuleOrph) (mi_rules new_iface)
420 addVersionInfo (Just old_iface@(ModIface { mi_mod_vers = old_mod_vers,
421 mi_exp_vers = old_exp_vers,
422 mi_rule_vers = old_rule_vers,
423 mi_decls = old_decls,
424 mi_ver_fn = old_decl_vers,
425 mi_fix_fn = old_fixities }))
426 new_iface@(ModIface { mi_fix_fn = new_fixities })
429 | no_change_at_all = (old_iface, True, ptext SLIT("Interface file unchanged"), pp_orphs)
430 | otherwise = (final_iface, False, vcat [ptext SLIT("Interface file has changed"),
431 nest 2 pp_diffs], pp_orphs)
433 final_iface = new_iface { mi_mod_vers = bump_unless no_output_change old_mod_vers,
434 mi_exp_vers = bump_unless no_export_change old_exp_vers,
435 mi_rule_vers = bump_unless no_rule_change old_rule_vers,
436 mi_orphan = not (null new_orph_rules && null new_orph_insts),
437 mi_decls = decls_w_vers,
438 mi_ver_fn = mkIfaceVerCache decls_w_vers }
440 decls_w_vers = [(add_vers decl, decl) | decl <- new_decls]
443 (old_non_orph_insts, old_orph_insts) = mkOrphMap ifInstOrph (mi_insts old_iface)
444 (new_non_orph_insts, new_orph_insts) = mkOrphMap ifInstOrph (mi_insts new_iface)
445 same_insts occ = eqMaybeBy (eqListBy eqIfInst)
446 (lookupOccEnv old_non_orph_insts occ)
447 (lookupOccEnv new_non_orph_insts occ)
449 (old_non_orph_rules, old_orph_rules) = mkOrphMap ifRuleOrph (mi_rules old_iface)
450 (new_non_orph_rules, new_orph_rules) = mkOrphMap ifRuleOrph (mi_rules new_iface)
451 same_rules occ = eqMaybeBy (eqListBy eqIfRule)
452 (lookupOccEnv old_non_orph_rules occ)
453 (lookupOccEnv new_non_orph_rules occ)
455 -- Computing what changed
456 no_output_change = no_decl_change && no_rule_change &&
457 no_export_change && no_deprec_change
458 no_export_change = mi_exports new_iface == mi_exports old_iface -- Kept sorted
459 no_decl_change = isEmptyOccSet changed_occs
460 no_rule_change = not (changedWrt changed_occs (eqListBy eqIfRule old_orph_rules new_orph_rules)
461 || changedWrt changed_occs (eqListBy eqIfInst old_orph_insts new_orph_insts))
462 no_deprec_change = mi_deprecs new_iface == mi_deprecs old_iface
464 -- If the usages havn't changed either, we don't need to write the interface file
465 no_other_changes = mi_usages new_iface == mi_usages old_iface &&
466 mi_deps new_iface == mi_deps old_iface
467 no_change_at_all = no_output_change && no_other_changes
469 pp_diffs = vcat [pp_change no_export_change "Export list"
470 (ppr old_exp_vers <+> arrow <+> ppr (mi_exp_vers final_iface)),
471 pp_change no_rule_change "Rules"
472 (ppr old_rule_vers <+> arrow <+> ppr (mi_rule_vers final_iface)),
473 pp_change no_deprec_change "Deprecations" empty,
474 pp_change no_other_changes "Usages" empty,
476 pp_change True what info = empty
477 pp_change False what info = text what <+> ptext SLIT("changed") <+> info
480 old_decl_env = mkOccEnv [(ifName decl, decl) | (_,decl) <- old_decls]
481 same_fixity n = bool (old_fixities n == new_fixities n)
484 -- Adding version info
485 new_version = bumpVersion old_mod_vers
486 add_vers decl | occ `elemOccSet` changed_occs = new_version
487 | otherwise = expectJust "add_vers" (old_decl_vers occ)
488 -- If it's unchanged, there jolly well
489 where -- should be an old version number
493 changed_occs :: OccSet
494 changed_occs = computeChangedOccs eq_info
496 eq_info :: [(OccName, IfaceEq)]
497 eq_info = map check_eq new_decls
498 check_eq new_decl | Just old_decl <- lookupOccEnv old_decl_env occ
499 = (occ, new_decl `eqIfDecl` old_decl &&&
500 eq_indirects new_decl)
501 | otherwise {- No corresponding old decl -}
504 occ = ifName new_decl
506 eq_indirects :: IfaceDecl -> IfaceEq
507 -- When seeing if two decls are the same, remember to
508 -- check whether any relevant fixity or rules have changed
509 eq_indirects (IfaceId {ifName = occ}) = eq_ind_occ occ
510 eq_indirects (IfaceClass {ifName = cls_occ, ifSigs = sigs})
511 = same_insts cls_occ &&&
512 eq_ind_occs [op | IfaceClassOp op _ _ <- sigs]
513 eq_indirects (IfaceData {ifName = tc_occ, ifCons = cons})
514 = same_insts tc_occ &&& same_fixity tc_occ &&& -- The TyCon can have a fixity too
515 eq_ind_occs (map ifConOcc (visibleIfConDecls cons))
516 eq_indirects other = Equal -- Synonyms and foreign declarations
518 eq_ind_occ :: OccName -> IfaceEq -- For class ops and Ids; check fixity and rules
519 eq_ind_occ occ = same_fixity occ &&& same_rules occ
520 eq_ind_occs = foldr ((&&&) . eq_ind_occ) Equal
524 pp_decl_diffs :: SDoc -- Nothing => no changes
526 | isEmptyOccSet changed_occs = empty
528 = vcat [ptext SLIT("Changed occs:") <+> ppr (occSetElts changed_occs),
529 ptext SLIT("Version change for these decls:"),
530 nest 2 (vcat (map show_change new_decls))]
532 eq_env = mkOccEnv eq_info
534 | not (occ `elemOccSet` changed_occs) = empty
536 = vcat [ppr occ <+> ppr (old_decl_vers occ) <+> arrow <+> ppr new_version,
539 occ = ifName new_decl
540 why = case lookupOccEnv eq_env occ of
541 Just (EqBut occs) -> sep [ppr occ <> colon, ptext SLIT("Free vars (only) changed:"),
542 nest 2 (braces (fsep (map ppr (occSetElts
543 (occs `intersectOccSet` changed_occs)))))]
545 | Just old_decl <- lookupOccEnv old_decl_env occ
546 -> vcat [ptext SLIT("Old:") <+> ppr old_decl,
547 ptext SLIT("New:") <+> ppr new_decl]
549 -> ppr occ <+> ptext SLIT("only in new interface")
550 other -> pprPanic "MkIface.show_change" (ppr occ)
552 pp_orphs = pprOrphans new_orph_insts new_orph_rules
554 pprOrphans insts rules
555 | null insts && null rules = Nothing
558 if null insts then empty else
559 hang (ptext SLIT("Warning: orphan instances:"))
560 2 (vcat (map ppr insts)),
561 if null rules then empty else
562 hang (ptext SLIT("Warning: orphan rules:"))
563 2 (vcat (map ppr rules))
566 computeChangedOccs :: [(OccName, IfaceEq)] -> OccSet
567 computeChangedOccs eq_info
568 = foldl add_changes emptyOccSet (stronglyConnComp edges)
570 edges :: [((OccName,IfaceEq), Unique, [Unique])]
571 edges = [ (node, getUnique occ, map getUnique occs)
572 | node@(occ, iface_eq) <- eq_info
573 , let occs = case iface_eq of
574 EqBut occ_set -> occSetElts occ_set
577 -- Changes in declarations
578 add_changes :: OccSet -> SCC (OccName, IfaceEq) -> OccSet
579 add_changes so_far (AcyclicSCC (occ, iface_eq))
580 | changedWrt so_far iface_eq -- This one has changed
581 = extendOccSet so_far occ
582 add_changes so_far (CyclicSCC pairs)
583 | changedWrt so_far (foldr1 (&&&) (map snd pairs)) -- One of this group has changed
584 = extendOccSetList so_far (map fst pairs)
585 add_changes so_far other = so_far
587 changedWrt :: OccSet -> IfaceEq -> Bool
588 changedWrt so_far Equal = False
589 changedWrt so_far NotEqual = True
590 changedWrt so_far (EqBut kids) = so_far `intersectsOccSet` kids
592 ----------------------
593 -- mkOrphMap partitions instance decls or rules into
594 -- (a) an OccEnv for ones that are not orphans,
595 -- mapping the local OccName to a list of its decls
596 -- (b) a list of orphan decls
597 mkOrphMap :: (decl -> Maybe OccName) -- (Just occ) for a non-orphan decl, keyed by occ
598 -- Nothing for an orphan decl
599 -> [decl] -- Sorted into canonical order
600 -> (OccEnv [decl], -- Non-orphan decls associated with their key;
601 -- each sublist in canonical order
602 [decl]) -- Orphan decls; in canonical order
603 mkOrphMap get_key decls
604 = foldl go (emptyOccEnv, []) decls
606 go (non_orphs, orphs) d
607 | Just occ <- get_key d
608 = (extendOccEnv_C (\ ds _ -> d:ds) non_orphs occ [d], orphs)
609 | otherwise = (non_orphs, d:orphs)
611 anyNothing :: (a -> Maybe b) -> [a] -> Bool
612 anyNothing p [] = False
613 anyNothing p (x:xs) = isNothing (p x) || anyNothing p xs
615 ----------------------
616 mkIfaceDeprec :: Deprecations -> IfaceDeprecs
617 mkIfaceDeprec NoDeprecs = NoDeprecs
618 mkIfaceDeprec (DeprecAll t) = DeprecAll t
619 mkIfaceDeprec (DeprecSome env) = DeprecSome (sortLe (<=) (nameEnvElts env))
621 ----------------------
622 bump_unless :: Bool -> Version -> Version
623 bump_unless True v = v -- True <=> no change
624 bump_unless False v = bumpVersion v
628 %*********************************************************
630 \subsection{Keeping track of what we've slurped, and version numbers}
632 %*********************************************************
636 mkUsageInfo :: HscEnv
638 -> ModuleEnv (Module, Bool, SrcSpan)
639 -> [(Module, IsBootInterface)]
640 -> NameSet -> IO [Usage]
641 mkUsageInfo hsc_env hmods dir_imp_mods dep_mods used_names
642 = do { eps <- hscEPS hsc_env
643 ; let usages = mk_usage_info (eps_PIT eps) hsc_env hmods
644 dir_imp_mods dep_mods used_names
645 ; usages `seqList` return usages }
646 -- seq the list of Usages returned: occasionally these
647 -- don't get evaluated for a while and we can end up hanging on to
648 -- the entire collection of Ifaces.
650 mk_usage_info pit hsc_env hmods dir_imp_mods dep_mods proto_used_names
651 = mapCatMaybes mkUsage dep_mods
652 -- ToDo: do we need to sort into canonical order?
654 hpt = hsc_HPT hsc_env
656 used_names = mkNameSet $ -- Eliminate duplicates
657 [ nameParent n -- Just record usage on the 'main' names
658 | n <- nameSetToList proto_used_names
659 , not (isWiredInName n) -- Don't record usages for wired-in names
660 , isExternalName n -- Ignore internal names
663 -- ent_map groups together all the things imported and used
664 -- from a particular module in this package
665 ent_map :: ModuleEnv [OccName]
666 ent_map = foldNameSet add_mv emptyModuleEnv used_names
667 add_mv name mv_map = extendModuleEnv_C add_item mv_map mod [occ]
669 occ = nameOccName name
670 mod = nameModule name
671 add_item occs _ = occ:occs
673 depend_on_exports mod = case lookupModuleEnv dir_imp_mods mod of
674 Just (_,no_imp,_) -> not no_imp
677 -- We want to create a Usage for a home module if
678 -- a) we used something from; has something in used_names
679 -- b) we imported all of it, even if we used nothing from it
680 -- (need to recompile if its export list changes: export_vers)
681 -- c) is a home-package orphan module (need to recompile if its
682 -- instance decls change: rules_vers)
683 mkUsage :: (Module, Bool) -> Maybe Usage
684 mkUsage (mod_name, _)
685 | isNothing maybe_iface -- We can't depend on it if we didn't
686 || not (isHomeModule hmods mod) -- even open the interface!
688 && isNothing export_vers
690 = Nothing -- Record no usage info
693 = Just (Usage { usg_name = mod,
695 usg_exports = export_vers,
696 usg_entities = ent_vers,
697 usg_rules = rules_vers })
699 maybe_iface = lookupIfaceByModule hpt pit mod_name
700 -- In one-shot mode, the interfaces for home-package
701 -- modules accumulate in the PIT not HPT. Sigh.
703 Just iface = maybe_iface
704 mod = mi_module iface
705 orphan_mod = mi_orphan iface
706 version_env = mi_ver_fn iface
707 mod_vers = mi_mod_vers iface
708 rules_vers = mi_rule_vers iface
709 export_vers | depend_on_exports mod = Just (mi_exp_vers iface)
710 | otherwise = Nothing
712 -- The sort is to put them into canonical order
713 used_occs = lookupModuleEnv ent_map mod `orElse` []
714 ent_vers :: [(OccName,Version)]
715 ent_vers = [ (occ, version_env occ `orElse` initialVersion)
716 | occ <- sortLe (<=) used_occs]
720 mkIfaceExports :: NameSet -> [(Module, [GenAvailInfo OccName])]
721 -- Group by module and sort by occurrence
722 -- This keeps the list in canonical order
723 mkIfaceExports exports
724 = [ (mkModuleFS fs, eltsFM avails)
725 | (fs, avails) <- fmToList groupFM
728 groupFM :: FiniteMap FastString (FiniteMap FastString (GenAvailInfo OccName))
729 -- Deliberately use the FastString so we
730 -- get a canonical ordering
731 groupFM = foldl add emptyFM (nameSetToList exports)
733 add env name = addToFM_C add_avail env mod_fs
734 (unitFM avail_fs avail)
736 occ = nameOccName name
737 mod_fs = moduleFS (nameModule name)
738 avail | Just p <- nameParent_maybe name = AvailTC (nameOccName p) [occ]
739 | isTcOcc occ = AvailTC occ [occ]
740 | otherwise = Avail occ
741 avail_fs = occNameFS (availName avail)
742 add_avail avail_fm _ = addToFM_C add_item avail_fm avail_fs avail
744 add_item (AvailTC p occs) _ = AvailTC p (List.insert occ occs)
745 add_item (Avail n) _ = pprPanic "MkIface.addAvail" (ppr n <+> ppr name)
749 %************************************************************************
751 Load the old interface file for this module (unless
752 we have it aleady), and check whether it is up to date
755 %************************************************************************
758 checkOldIface :: HscEnv
760 -> Bool -- Source unchanged
761 -> Maybe ModIface -- Old interface from compilation manager, if any
762 -> IO (RecompileRequired, Maybe ModIface)
764 checkOldIface hsc_env mod_summary source_unchanged maybe_iface
765 = do { showPass (hsc_dflags hsc_env)
766 ("Checking old interface for " ++ moduleString (ms_mod mod_summary)) ;
768 ; initIfaceCheck hsc_env $
769 check_old_iface mod_summary source_unchanged maybe_iface
772 check_old_iface mod_summary source_unchanged maybe_iface
773 = -- CHECK WHETHER THE SOURCE HAS CHANGED
774 ifM (not source_unchanged)
775 (traceHiDiffs (nest 4 (text "Source file changed or recompilation check turned off")))
778 -- If the source has changed and we're in interactive mode, avoid reading
779 -- an interface; just return the one we might have been supplied with.
780 getGhcMode `thenM` \ ghc_mode ->
781 if (ghc_mode == Interactive || ghc_mode == JustTypecheck)
782 && not source_unchanged then
783 returnM (outOfDate, maybe_iface)
786 case maybe_iface of {
787 Just old_iface -> -- Use the one we already have
788 checkVersions source_unchanged old_iface `thenM` \ recomp ->
789 returnM (recomp, Just old_iface)
793 -- Try and read the old interface for the current module
794 -- from the .hi file left from the last time we compiled it
796 iface_path = msHiFilePath mod_summary
798 readIface (ms_mod mod_summary) iface_path False `thenM` \ read_result ->
799 case read_result of {
800 Failed err -> -- Old interface file not found, or garbled; give up
801 traceIf (text "FYI: cannot read old interface file:"
802 $$ nest 4 err) `thenM_`
803 returnM (outOfDate, Nothing)
807 -- We have got the old iface; check its versions
808 checkVersions source_unchanged iface `thenM` \ recomp ->
809 returnM (recomp, Just iface)
813 @recompileRequired@ is called from the HscMain. It checks whether
814 a recompilation is required. It needs access to the persistent state,
815 finder, etc, because it may have to load lots of interface files to
816 check their versions.
819 type RecompileRequired = Bool
820 upToDate = False -- Recompile not required
821 outOfDate = True -- Recompile required
823 checkVersions :: Bool -- True <=> source unchanged
824 -> ModIface -- Old interface
825 -> IfG RecompileRequired
826 checkVersions source_unchanged iface
827 | not source_unchanged
830 = do { traceHiDiffs (text "Considering whether compilation is required for" <+>
831 ppr (mi_module iface) <> colon)
833 -- Source code unchanged and no errors yet... carry on
835 -- First put the dependent-module info, read from the old interface, into the envt,
836 -- so that when we look for interfaces we look for the right one (.hi or .hi-boot)
838 -- It's just temporary because either the usage check will succeed
839 -- (in which case we are done with this module) or it'll fail (in which
840 -- case we'll compile the module from scratch anyhow).
842 -- We do this regardless of compilation mode
843 ; updateEps_ $ \eps -> eps { eps_is_boot = mod_deps }
845 ; checkList [checkModUsage u | u <- mi_usages iface]
848 -- This is a bit of a hack really
849 mod_deps :: ModuleEnv (Module, IsBootInterface)
850 mod_deps = mkModDeps (dep_mods (mi_deps iface))
852 checkModUsage :: Usage -> IfG RecompileRequired
853 -- Given the usage information extracted from the old
854 -- M.hi file for the module being compiled, figure out
855 -- whether M needs to be recompiled.
857 checkModUsage (Usage { usg_name = mod_name, usg_mod = old_mod_vers,
858 usg_rules = old_rule_vers,
859 usg_exports = maybe_old_export_vers,
860 usg_entities = old_decl_vers })
861 = -- Load the imported interface is possible
863 doc_str = sep [ptext SLIT("need version info for"), ppr mod_name]
865 traceHiDiffs (text "Checking usages for module" <+> ppr mod_name) `thenM_`
867 loadInterface doc_str mod_name ImportBySystem `thenM` \ mb_iface ->
868 -- Load the interface, but don't complain on failure;
869 -- Instead, get an Either back which we can test
872 Failed exn -> (out_of_date (sep [ptext SLIT("Can't find version number for module"),
874 -- Couldn't find or parse a module mentioned in the
875 -- old interface file. Don't complain -- it might just be that
876 -- the current module doesn't need that import and it's been deleted
880 new_mod_vers = mi_mod_vers iface
881 new_decl_vers = mi_ver_fn iface
882 new_export_vers = mi_exp_vers iface
883 new_rule_vers = mi_rule_vers iface
886 checkModuleVersion old_mod_vers new_mod_vers `thenM` \ recompile ->
887 if not recompile then
892 if checkExportList maybe_old_export_vers new_export_vers then
893 out_of_date_vers (ptext SLIT(" Export list changed"))
894 (expectJust "checkModUsage" maybe_old_export_vers)
899 if old_rule_vers /= new_rule_vers then
900 out_of_date_vers (ptext SLIT(" Rules changed"))
901 old_rule_vers new_rule_vers
904 -- CHECK ITEMS ONE BY ONE
905 checkList [checkEntityUsage new_decl_vers u | u <- old_decl_vers] `thenM` \ recompile ->
907 returnM outOfDate -- This one failed, so just bail out now
909 up_to_date (ptext SLIT(" Great! The bits I use are up to date"))
912 ------------------------
913 checkModuleVersion old_mod_vers new_mod_vers
914 | new_mod_vers == old_mod_vers
915 = up_to_date (ptext SLIT("Module version unchanged"))
918 = out_of_date_vers (ptext SLIT(" Module version has changed"))
919 old_mod_vers new_mod_vers
921 ------------------------
922 checkExportList Nothing new_vers = upToDate
923 checkExportList (Just v) new_vers = v /= new_vers
925 ------------------------
926 checkEntityUsage new_vers (name,old_vers)
927 = case new_vers name of
929 Nothing -> -- We used it before, but it ain't there now
930 out_of_date (sep [ptext SLIT("No longer exported:"), ppr name])
932 Just new_vers -- It's there, but is it up to date?
933 | new_vers == old_vers -> traceHiDiffs (text " Up to date" <+> ppr name <+> parens (ppr new_vers)) `thenM_`
935 | otherwise -> out_of_date_vers (ptext SLIT(" Out of date:") <+> ppr name)
938 up_to_date msg = traceHiDiffs msg `thenM_` returnM upToDate
939 out_of_date msg = traceHiDiffs msg `thenM_` returnM outOfDate
940 out_of_date_vers msg old_vers new_vers
941 = out_of_date (hsep [msg, ppr old_vers, ptext SLIT("->"), ppr new_vers])
943 ----------------------
944 checkList :: [IfG RecompileRequired] -> IfG RecompileRequired
945 -- This helper is used in two places
946 checkList [] = returnM upToDate
947 checkList (check:checks) = check `thenM` \ recompile ->
954 %************************************************************************
958 %************************************************************************
961 showIface :: FilePath -> IO ()
962 -- Read binary interface, and print it out
963 showIface filename = do
964 -- skip the version check; we don't want to worry about profiled vs.
965 -- non-profiled interfaces, for example.
966 writeIORef v_IgnoreHiWay True
967 iface <- Binary.getBinFileWithDict filename
968 printDump (pprModIface iface)
974 pprModIface :: ModIface -> SDoc
977 = vcat [ ptext SLIT("interface")
978 <+> ppr_package (mi_package iface)
979 <+> ppr (mi_module iface) <+> pp_boot
980 <+> ppr (mi_mod_vers iface) <+> pp_sub_vers
981 <+> (if mi_orphan iface then ptext SLIT("[orphan module]") else empty)
982 <+> int opt_HiVersion
983 <+> ptext SLIT("where")
984 , vcat (map pprExport (mi_exports iface))
985 , pprDeps (mi_deps iface)
986 , vcat (map pprUsage (mi_usages iface))
987 , pprFixities (mi_fixities iface)
988 , vcat (map pprIfaceDecl (mi_decls iface))
989 , vcat (map ppr (mi_insts iface))
990 , vcat (map ppr (mi_rules iface))
991 , pprDeprecs (mi_deprecs iface)
994 pp_boot | mi_boot iface = ptext SLIT("[boot]")
996 ppr_package HomePackage = empty
997 ppr_package (ExtPackage id) = doubleQuotes (ppr id)
999 exp_vers = mi_exp_vers iface
1000 rule_vers = mi_rule_vers iface
1002 pp_sub_vers | exp_vers == initialVersion && rule_vers == initialVersion = empty
1003 | otherwise = brackets (ppr exp_vers <+> ppr rule_vers)
1006 When printing export lists, we print like this:
1008 AvailTC C [C, x, y] C(x,y)
1009 AvailTC C [x, y] C!(x,y) -- Exporting x, y but not C
1012 pprExport :: IfaceExport -> SDoc
1013 pprExport (mod, items)
1014 = hsep [ ptext SLIT("export"), ppr mod, hsep (map pp_avail items) ]
1016 pp_avail :: GenAvailInfo OccName -> SDoc
1017 pp_avail (Avail occ) = ppr occ
1018 pp_avail (AvailTC _ []) = empty
1019 pp_avail (AvailTC n (n':ns))
1020 | n==n' = ppr n <> pp_export ns
1021 | otherwise = ppr n <> char '|' <> pp_export (n':ns)
1023 pp_export [] = empty
1024 pp_export names = braces (hsep (map ppr names))
1026 pprUsage :: Usage -> SDoc
1028 = hsep [ptext SLIT("import"), ppr (usg_name usage),
1029 int (usg_mod usage),
1030 pp_export_version (usg_exports usage),
1031 int (usg_rules usage),
1032 pp_versions (usg_entities usage) ]
1034 pp_versions nvs = hsep [ ppr n <+> int v | (n,v) <- nvs ]
1035 pp_export_version Nothing = empty
1036 pp_export_version (Just v) = int v
1038 pprDeps :: Dependencies -> SDoc
1039 pprDeps (Deps { dep_mods = mods, dep_pkgs = pkgs, dep_orphs = orphs})
1040 = vcat [ptext SLIT("module dependencies:") <+> fsep (map ppr_mod mods),
1041 ptext SLIT("package dependencies:") <+> fsep (map ppr pkgs),
1042 ptext SLIT("orphans:") <+> fsep (map ppr orphs)
1045 ppr_mod (mod_name, boot) = ppr mod_name <+> ppr_boot boot
1046 ppr_boot True = text "[boot]"
1047 ppr_boot False = empty
1049 pprIfaceDecl :: (Version, IfaceDecl) -> SDoc
1050 pprIfaceDecl (ver, decl)
1051 = ppr_vers ver <+> ppr decl
1053 -- Print the version for the decl
1054 ppr_vers v | v == initialVersion = empty
1057 pprFixities :: [(OccName, Fixity)] -> SDoc
1058 pprFixities [] = empty
1059 pprFixities fixes = ptext SLIT("fixities") <+> pprWithCommas pprFix fixes
1061 pprFix (occ,fix) = ppr fix <+> ppr occ
1063 pprDeprecs NoDeprecs = empty
1064 pprDeprecs (DeprecAll txt) = ptext SLIT("Deprecate all") <+> doubleQuotes (ftext txt)
1065 pprDeprecs (DeprecSome prs) = ptext SLIT("Deprecate") <+> vcat (map pprDeprec prs)
1067 pprDeprec (name, txt) = ppr name <+> doubleQuotes (ftext txt)