PackageIndex.hs 24.1 KB
Newer Older
ttuegel's avatar
ttuegel committed
1 2
{-# LANGUAGE DeriveGeneric #-}

3 4
-----------------------------------------------------------------------------
-- |
5
-- Module      :  Distribution.Simple.PackageIndex
6 7
-- Copyright   :  (c) David Himmelstrup 2005,
--                    Bjorn Bringert 2007,
Duncan Coutts's avatar
Duncan Coutts committed
8
--                    Duncan Coutts 2008-2009
9
--
Duncan Coutts's avatar
Duncan Coutts committed
10
-- Maintainer  :  cabal-devel@haskell.org
11 12
-- Portability :  portable
--
13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
-- An index of packages whose primary key is 'UnitId'.  Public libraries
-- are additionally indexed by 'PackageName' and 'Version'.
-- Technically, these are an index of *units* (so we should eventually
-- rename it to 'UnitIndex'); but in the absence of internal libraries
-- or Backpack each unit is equivalent to a package.
--
-- 'PackageIndex' is parametric over what it actually records, and it
-- is used in two ways:
--
--      * The 'InstalledPackageIndex' (defined here) contains a graph of
--        'InstalledPackageInfo's representing the packages in a
--        package database stack.  It is used in a variety of ways:
--
--          * The primary use to let Cabal access the same installed
--            package database which is used by GHC during compilation.
--            For example, this data structure is used by 'ghc-pkg'
--            and 'Cabal' to do consistency checks on the database
--            (are the references closed).
--
--          * Given a set of dependencies, we can compute the transitive
--            closure of dependencies.  This is to check if the versions
--            of packages are consistent, and also needed by multiple
--            tools (Haddock must be explicitly told about the every
--            transitive package to do cross-package linking;
--            preprocessors must know about the include paths of all
--            transitive dependencies.)
--
--      * The 'PlanIndex' (defined in 'Distribution.Client.InstallPlan'),
--        contains a graph of 'GenericPlanPackage'.  Ignoring its type
--        parameters for a moment, a 'PlanIndex' is an extension of the
--        'InstalledPackageIndex' to also record nodes for packages
--        which are *planned* to be installed, but not actually
--        installed yet.  A 'PlanIndex' containing only 'PreExisting'
--        packages is essentially a 'PackageIndex'.
--
--        'PlanIndex'es actually require some auxiliary information, so
--        most users interact with a 'GenericInstallPlan'.  This type is
--        specialized as an 'ElaboratedInstallPlan' (for @cabal
--        new-build@) or an 'InstallPlan' (for @cabal install@).
--
-- This 'PackageIndex' is NOT to be confused with
-- 'Distribution.Client.PackageIndex', which indexes packages only by
-- 'PackageName' (this makes it suitable for indexing source packages,
-- for which we don't know 'UnitId's.)
Duncan Coutts's avatar
Duncan Coutts committed
57
--
58 59
module Distribution.Simple.PackageIndex (
  -- * Package index data type
60
  InstalledPackageIndex,
61
  PackageIndex,
62

63
  -- * Creating an index
64 65
  fromList,

66
  -- * Updates
67
  merge,
Duncan Coutts's avatar
Duncan Coutts committed
68

69
  insert,
Duncan Coutts's avatar
Duncan Coutts committed
70

71
  deleteUnitId,
Duncan Coutts's avatar
Duncan Coutts committed
72
  deleteSourcePackageId,
73
  deletePackageName,
Duncan Coutts's avatar
Duncan Coutts committed
74
--  deleteDependency,
75 76 77 78

  -- * Queries

  -- ** Precise lookups
79
  lookupUnitId,
80
  lookupComponentId,
Duncan Coutts's avatar
Duncan Coutts committed
81
  lookupSourcePackageId,
82
  lookupPackageId,
83
  lookupPackageName,
84 85 86 87 88 89 90 91 92 93
  lookupDependency,

  -- ** Case-insensitive searches
  searchByName,
  SearchResult(..),
  searchByNameSubstring,

  -- ** Bulk queries
  allPackages,
  allPackagesByName,
94
  allPackagesBySourcePackageId,
95 96 97 98 99 100 101 102 103 104

  -- ** Special queries
  brokenPackages,
  dependencyClosure,
  reverseDependencyClosure,
  topologicalOrder,
  reverseTopologicalOrder,
  dependencyInconsistencies,
  dependencyCycles,
  dependencyGraph,
Duncan Coutts's avatar
Duncan Coutts committed
105
  moduleNameIndex,
106 107 108 109

  -- * Backwards compatibility
  deleteInstalledPackageId,
  lookupInstalledPackageId,
110 111
  ) where

112 113 114
import Prelude ()
import Distribution.Compat.Prelude hiding (lookup)

115
import Distribution.Package
116
import Distribution.Backpack
117 118 119 120 121
import Distribution.ModuleName
import qualified Distribution.InstalledPackageInfo as IPI
import Distribution.Version
import Distribution.Simple.Utils

122
import Control.Exception (assert)
123
import Data.Array ((!))
ttuegel's avatar
ttuegel committed
124 125
import qualified Data.Array as Array
import qualified Data.Graph as Graph
126
import Data.List as List ( groupBy,  deleteBy, deleteFirstsBy )
ttuegel's avatar
ttuegel committed
127 128
import qualified Data.Map as Map
import qualified Data.Tree  as Tree
129 130

-- | The collection of information about packages from one or more 'PackageDB's.
131
-- These packages generally should have an instance of 'PackageInstalled'
132
--
133
-- Packages are uniquely identified in by their 'UnitId', they can
Ian D. Bollinger's avatar
Ian D. Bollinger committed
134
-- also be efficiently looked up by package name or by name and version.
135
--
136
data PackageIndex a = PackageIndex {
Duncan Coutts's avatar
Duncan Coutts committed
137
  -- The primary index. Each InstalledPackageInfo record is uniquely identified
138
  -- by its UnitId.
Duncan Coutts's avatar
Duncan Coutts committed
139
  --
140
  unitIdIndex :: !(Map UnitId a),
Duncan Coutts's avatar
Duncan Coutts committed
141

Ian D. Bollinger's avatar
Ian D. Bollinger committed
142
  -- This auxiliary index maps package names (case-sensitively) to all the
Duncan Coutts's avatar
Duncan Coutts committed
143 144
  -- versions and instances of that package. This allows us to find all
  -- versions satisfying a dependency.
145
  --
Duncan Coutts's avatar
Duncan Coutts committed
146 147
  -- It is a three-level index. The first level is the package name,
  -- the second is the package version and the final level is instances
148
  -- of the same package version. These are unique by UnitId
Duncan Coutts's avatar
Duncan Coutts committed
149
  -- and are kept in preference order.
150
  --
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
151 152
  -- FIXME: Clarify what "preference order" means. Check that this invariant is
  -- preserved. See #1463 for discussion.
153
  packageIdIndex :: !(Map PackageName (Map Version [a]))
154

155
  } deriving (Eq, Generic, Show, Read)
ttuegel's avatar
ttuegel committed
156 157

instance Binary a => Binary (PackageIndex a)
Duncan Coutts's avatar
Duncan Coutts committed
158

159 160
-- | The default package index which contains 'InstalledPackageInfo'.  Normally
-- use this.
161
type InstalledPackageIndex = PackageIndex IPI.InstalledPackageInfo
162

163
instance HasUnitId a => Monoid (PackageIndex a) where
Duncan Coutts's avatar
Duncan Coutts committed
164
  mempty  = PackageIndex Map.empty Map.empty
165
  mappend = (<>)
166
  --save one mappend with empty in the common case:
167
  mconcat [] = mempty
168 169
  mconcat xs = foldr1 mappend xs

170
instance HasUnitId a => Semigroup (PackageIndex a) where
171 172
  (<>) = merge

173
invariant :: HasUnitId a => PackageIndex a -> Bool
Duncan Coutts's avatar
Duncan Coutts committed
174
invariant (PackageIndex pids pnames) =
175
     map installedUnitId (Map.elems pids)
176
  == sort
177
     [ assert pinstOk (installedUnitId pinst)
Duncan Coutts's avatar
Duncan Coutts committed
178 179 180
     | (pname, pvers)  <- Map.toList pnames
     , let pversOk = not (Map.null pvers)
     , (pver,  pinsts) <- assert pversOk $ Map.toList pvers
181
     , let pinsts'  = sortBy (comparing installedUnitId) pinsts
Duncan Coutts's avatar
Duncan Coutts committed
182
           pinstsOk = all (\g -> length g == 1)
183
                          (groupBy (equating installedUnitId) pinsts')
Duncan Coutts's avatar
Duncan Coutts committed
184 185 186 187 188
     , pinst           <- assert pinstsOk $ pinsts'
     , let pinstOk = packageName    pinst == pname
                  && packageVersion pinst == pver
     ]

189

190 191 192 193
--
-- * Internal helpers
--

194 195
mkPackageIndex :: HasUnitId a
               => Map UnitId a
196 197
               -> Map PackageName (Map Version [a])
               -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
198 199
mkPackageIndex pids pnames = assert (invariant index) index
  where index = PackageIndex pids pnames
200

201 202 203

--
-- * Construction
204 205
--

206
-- | Build an index out of a bunch of packages.
207
--
208
-- If there are duplicates by 'UnitId' then later ones mask earlier
Duncan Coutts's avatar
Duncan Coutts committed
209
-- ones.
210
--
211
fromList :: HasUnitId a => [a] -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
212
fromList pkgs = mkPackageIndex pids pnames
213
  where
214
    pids      = Map.fromList [ (installedUnitId pkg, pkg) | pkg <- pkgs ]
Duncan Coutts's avatar
Duncan Coutts committed
215 216 217 218 219 220 221 222 223
    pnames    =
      Map.fromList
        [ (packageName (head pkgsN), pvers)
        | pkgsN <- groupBy (equating  packageName)
                 . sortBy  (comparing packageId)
                 $ pkgs
        , let pvers =
                Map.fromList
                [ (packageVersion (head pkgsNV),
224
                   nubBy (equating installedUnitId) (reverse pkgsNV))
Duncan Coutts's avatar
Duncan Coutts committed
225 226 227
                | pkgsNV <- groupBy (equating packageVersion) pkgsN
                ]
        ]
228

229 230 231 232
--
-- * Updates
--

233 234
-- | Merge two indexes.
--
Duncan Coutts's avatar
Duncan Coutts committed
235
-- Packages from the second mask packages from the first if they have the exact
236
-- same 'UnitId'.
237
--
Duncan Coutts's avatar
Duncan Coutts committed
238 239 240 241 242
-- For packages with the same source 'PackageId', packages from the second are
-- \"preferred\" over those from the first. Being preferred means they are top
-- result when we do a lookup by source 'PackageId'. This is the mechanism we
-- use to prefer user packages over global packages.
--
243
merge :: HasUnitId a => PackageIndex a -> PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
244
      -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
245
merge (PackageIndex pids1 pnames1) (PackageIndex pids2 pnames2) =
246
  mkPackageIndex (Map.unionWith (\_ y -> y) pids1 pids2)
Duncan Coutts's avatar
Duncan Coutts committed
247 248 249 250 251
                 (Map.unionWith (Map.unionWith mergeBuckets) pnames1 pnames2)
  where
    -- Packages in the second list mask those in the first, however preferred
    -- packages go first in the list.
    mergeBuckets xs ys = ys ++ (xs \\ ys)
252
    (\\) = deleteFirstsBy (equating installedUnitId)
253

254

Duncan Coutts's avatar
Duncan Coutts committed
255
-- | Inserts a single package into the index.
256 257 258 259
--
-- This is equivalent to (but slightly quicker than) using 'mappend' or
-- 'merge' with a singleton index.
--
260
insert :: HasUnitId a => a -> PackageIndex a -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
261 262 263
insert pkg (PackageIndex pids pnames) =
    mkPackageIndex pids' pnames'

264
  where
265
    pids'   = Map.insert (installedUnitId pkg) pkg pids
Duncan Coutts's avatar
Duncan Coutts committed
266 267 268 269 270 271 272 273 274 275 276
    pnames' = insertPackageName pnames
    insertPackageName =
      Map.insertWith' (\_ -> insertPackageVersion)
                     (packageName pkg)
                     (Map.singleton (packageVersion pkg) [pkg])

    insertPackageVersion =
      Map.insertWith' (\_ -> insertPackageInstance)
                     (packageVersion pkg) [pkg]

    insertPackageInstance pkgs =
277
      pkg : deleteBy (equating installedUnitId) pkg pkgs
Duncan Coutts's avatar
Duncan Coutts committed
278 279 280 281


-- | Removes a single installed package from the index.
--
282
deleteUnitId :: HasUnitId a
283 284
             => UnitId -> PackageIndex a
             -> PackageIndex a
285
deleteUnitId ipkgid original@(PackageIndex pids pnames) =
Duncan Coutts's avatar
Duncan Coutts committed
286 287 288 289 290
  case Map.updateLookupWithKey (\_ _ -> Nothing) ipkgid pids of
    (Nothing,     _)     -> original
    (Just spkgid, pids') -> mkPackageIndex pids'
                                          (deletePkgName spkgid pnames)

Duncan Coutts's avatar
Duncan Coutts committed
291
  where
Duncan Coutts's avatar
Duncan Coutts committed
292 293 294 295 296 297
    deletePkgName spkgid =
      Map.update (deletePkgVersion spkgid) (packageName spkgid)

    deletePkgVersion spkgid =
        (\m -> if Map.null m then Nothing else Just m)
      . Map.update deletePkgInstance (packageVersion spkgid)
Duncan Coutts's avatar
Duncan Coutts committed
298

Duncan Coutts's avatar
Duncan Coutts committed
299
    deletePkgInstance =
300
        (\xs -> if null xs then Nothing else Just xs)
301
      . List.deleteBy (\_ pkg -> installedUnitId pkg == ipkgid) undefined
Duncan Coutts's avatar
Duncan Coutts committed
302

Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
303
-- | Backwards compatibility wrapper for Cabal pre-1.24.
304 305 306 307 308
{-# DEPRECATED deleteInstalledPackageId "Use deleteUnitId instead" #-}
deleteInstalledPackageId :: HasUnitId a
                         => UnitId -> PackageIndex a
                         -> PackageIndex a
deleteInstalledPackageId = deleteUnitId
Duncan Coutts's avatar
Duncan Coutts committed
309 310

-- | Removes all packages with this source 'PackageId' from the index.
311
--
312
deleteSourcePackageId :: HasUnitId a => PackageId -> PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
313
                      -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
314 315 316 317 318 319
deleteSourcePackageId pkgid original@(PackageIndex pids pnames) =
  case Map.lookup (packageName pkgid) pnames of
    Nothing     -> original
    Just pvers  -> case Map.lookup (packageVersion pkgid) pvers of
      Nothing   -> original
      Just pkgs -> mkPackageIndex
320
                     (foldl' (flip (Map.delete . installedUnitId)) pids pkgs)
Duncan Coutts's avatar
Duncan Coutts committed
321 322 323 324 325 326 327 328 329
                     (deletePkgName pnames)
  where
    deletePkgName =
      Map.update deletePkgVersion (packageName pkgid)

    deletePkgVersion =
        (\m -> if Map.null m then Nothing else Just m)
      . Map.delete (packageVersion pkgid)

330 331 332

-- | Removes all packages with this (case-sensitive) name from the index.
--
333
deletePackageName :: HasUnitId a => PackageName -> PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
334
                  -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
335 336 337 338
deletePackageName name original@(PackageIndex pids pnames) =
  case Map.lookup name pnames of
    Nothing     -> original
    Just pvers  -> mkPackageIndex
339
                     (foldl' (flip (Map.delete . installedUnitId)) pids
Duncan Coutts's avatar
Duncan Coutts committed
340 341
                             (concat (Map.elems pvers)))
                     (Map.delete name pnames)
342

Duncan Coutts's avatar
Duncan Coutts committed
343
{-
344 345
-- | Removes all packages satisfying this dependency from the index.
--
Duncan Coutts's avatar
Duncan Coutts committed
346
deleteDependency :: Dependency -> PackageIndex -> PackageIndex
347
deleteDependency (Dependency name verstionRange) =
Duncan Coutts's avatar
Duncan Coutts committed
348 349
  delete' name (\pkg -> packageVersion pkg `withinRange` verstionRange)
-}
350

351 352 353 354
--
-- * Bulk queries
--

355 356
-- | Get all the packages from the index.
--
357
allPackages :: PackageIndex a -> [a]
358
allPackages = Map.elems . unitIdIndex
359 360 361

-- | Get all the packages from the index.
--
362
-- They are grouped by package name (case-sensitively).
363
--
364
allPackagesByName :: PackageIndex a -> [(PackageName, [a])]
365
allPackagesByName index =
366
  [ (pkgname, concat (Map.elems pvers))
367
  | (pkgname, pvers) <- Map.toList (packageIdIndex index) ]
368 369 370 371 372

-- | Get all the packages from the index.
--
-- They are grouped by source package id (package name and version).
--
373
allPackagesBySourcePackageId :: HasUnitId a => PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
374
                             -> [(PackageId, [a])]
375
allPackagesBySourcePackageId index =
376
  [ (packageId ipkg, ipkgs)
377
  | pvers <- Map.elems (packageIdIndex index)
378
  , ipkgs@(ipkg:_) <- Map.elems pvers ]
379 380 381 382 383

--
-- * Lookups
--

384
-- | Does a lookup by unit identifier.
385
--
386
-- Since multiple package DBs mask each other by 'UnitId',
387 388
-- then we get back at most one package.
--
389
lookupUnitId :: PackageIndex a -> UnitId
390
             -> Maybe a
391
lookupUnitId index uid = Map.lookup uid (unitIdIndex index)
392 393 394 395 396 397

-- | Does a lookup by component identifier.  In the absence
-- of Backpack, this is just a 'lookupUnitId'.
--
lookupComponentId :: PackageIndex a -> ComponentId
                  -> Maybe a
398 399
lookupComponentId index cid =
    Map.lookup (newSimpleUnitId cid) (unitIdIndex index)
Duncan Coutts's avatar
Duncan Coutts committed
400

Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
401
-- | Backwards compatibility for Cabal pre-1.24.
402 403 404 405 406
{-# DEPRECATED lookupInstalledPackageId "Use lookupUnitId instead" #-}
lookupInstalledPackageId :: PackageIndex a -> UnitId
                         -> Maybe a
lookupInstalledPackageId = lookupUnitId

407

Duncan Coutts's avatar
Duncan Coutts committed
408 409 410
-- | Does a lookup by source package id (name & version).
--
-- There can be multiple installed packages with the same source 'PackageId'
411
-- but different 'UnitId'. They are returned in order of
Duncan Coutts's avatar
Duncan Coutts committed
412
-- preference, with the most preferred first.
413
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
414
lookupSourcePackageId :: PackageIndex a -> PackageId -> [a]
415 416
lookupSourcePackageId index pkgid =
  case Map.lookup (packageName pkgid) (packageIdIndex index) of
Duncan Coutts's avatar
Duncan Coutts committed
417 418 419 420
    Nothing     -> []
    Just pvers  -> case Map.lookup (packageVersion pkgid) pvers of
      Nothing   -> []
      Just pkgs -> pkgs -- in preference order
421

422 423
-- | Convenient alias of 'lookupSourcePackageId', but assuming only
-- one package per package ID.
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
424
lookupPackageId :: PackageIndex a -> PackageId -> Maybe a
425 426 427 428
lookupPackageId index pkgid = case lookupSourcePackageId index pkgid  of
    []    -> Nothing
    [pkg] -> Just pkg
    _     -> error "Distribution.Simple.PackageIndex: multiple matches found"
Duncan Coutts's avatar
Duncan Coutts committed
429 430 431

-- | Does a lookup by source package name.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
432
lookupPackageName :: PackageIndex a -> PackageName
433
                  -> [(Version, [a])]
434 435
lookupPackageName index name =
  case Map.lookup name (packageIdIndex index) of
Duncan Coutts's avatar
Duncan Coutts committed
436 437 438 439 440
    Nothing     -> []
    Just pvers  -> Map.toList pvers


-- | Does a lookup by source package name and a range of versions.
441 442 443 444
--
-- We get back any number of versions of the specified package name, all
-- satisfying the version range constraint.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
445
lookupDependency :: PackageIndex a -> Dependency
446
                 -> [(Version, [a])]
447 448
lookupDependency index (Dependency name versionRange) =
  case Map.lookup name (packageIdIndex index) of
Duncan Coutts's avatar
Duncan Coutts committed
449 450 451 452
    Nothing    -> []
    Just pvers -> [ entry
                  | entry@(ver, _) <- Map.toList pvers
                  , ver `withinRange` versionRange ]
453 454 455 456

--
-- * Case insensitive name lookups
--
457 458 459

-- | Does a case-insensitive search by package name.
--
Ian D. Bollinger's avatar
Ian D. Bollinger committed
460
-- If there is only one package that compares case-insensitively to this name
461
-- then the search is unambiguous and we get back all versions of that package.
Ian D. Bollinger's avatar
Ian D. Bollinger committed
462
-- If several match case-insensitively but one matches exactly then it is also
463 464
-- unambiguous.
--
Ian D. Bollinger's avatar
Ian D. Bollinger committed
465
-- If however several match case-insensitively and none match exactly then we
466 467 468 469
-- have an ambiguous result, and we get back all the versions of all the
-- packages. The list of ambiguous results is split by exact package name. So
-- it is a non-empty list of non-empty lists.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
470
searchByName :: PackageIndex a -> String -> SearchResult [a]
471
searchByName index name =
472 473
  case [ pkgs | pkgs@(pname,_) <- Map.toList (packageIdIndex index)
              , lowercase (unPackageName pname) == lname ] of
Duncan Coutts's avatar
Duncan Coutts committed
474 475
    []               -> None
    [(_,pvers)]      -> Unambiguous (concat (Map.elems pvers))
476
    pkgss            -> case find ((mkPackageName name ==) . fst) pkgss of
Duncan Coutts's avatar
Duncan Coutts committed
477 478
      Just (_,pvers) -> Unambiguous (concat (Map.elems pvers))
      Nothing        -> Ambiguous (map (concat . Map.elems . snd) pkgss)
479
  where lname = lowercase name
480 481 482 483 484 485 486

data SearchResult a = None | Unambiguous a | Ambiguous [a]

-- | Does a case-insensitive substring search by package name.
--
-- That is, all packages that contain the given string in their name.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
487
searchByNameSubstring :: PackageIndex a -> String -> [a]
488
searchByNameSubstring index searchterm =
489
  [ pkg
490 491
  | (pname, pvers) <- Map.toList (packageIdIndex index)
  , lsearchterm `isInfixOf` lowercase (unPackageName pname)
Duncan Coutts's avatar
Duncan Coutts committed
492
  , pkgs <- Map.elems pvers
493
  , pkg <- pkgs ]
494
  where lsearchterm = lowercase searchterm
495

Duncan Coutts's avatar
Duncan Coutts committed
496 497 498 499 500 501 502 503

--
-- * Special queries
--

-- None of the stuff below depends on the internal representation of the index.
--

504 505 506 507 508 509 510
-- | Find if there are any cycles in the dependency graph. If there are no
-- cycles the result is @[]@.
--
-- This actually computes the strongly connected components. So it gives us a
-- list of groups of packages where within each group they all depend on each
-- other, directly or indirectly.
--
511
dependencyCycles :: PackageInstalled a => PackageIndex a -> [[a]]
512
dependencyCycles index =
513 514
  [ vs | Graph.CyclicSCC vs <- Graph.stronglyConnComp adjacencyList ]
  where
515
    adjacencyList = [ (pkg, installedUnitId pkg, installedDepends pkg)
516 517 518
                    | pkg <- allPackages index ]


Duncan Coutts's avatar
Duncan Coutts committed
519
-- | All packages that have immediate dependencies that are not in the index.
520
--
521 522
-- Returns such packages along with the dependencies that they're missing.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
523
brokenPackages :: PackageInstalled a => PackageIndex a
524
               -> [(a, [UnitId])]
525
brokenPackages index =
526
  [ (pkg, missing)
Duncan Coutts's avatar
Duncan Coutts committed
527
  | pkg  <- allPackages index
528
  , let missing = [ pkg' | pkg' <- installedDepends pkg
529
                         , isNothing (lookupUnitId index pkg') ]
530 531
  , not (null missing) ]

532
-- | Tries to take the transitive closure of the package dependencies.
533
--
534
-- If the transitive closure is complete then it returns that subset of the
535 536 537
-- index. Otherwise it returns the broken packages as in 'brokenPackages'.
--
-- * Note that if the result is @Right []@ it is because at least one of
Duncan Coutts's avatar
Duncan Coutts committed
538
-- the original given 'PackageId's do not occur in the index.
539
--
540
dependencyClosure :: PackageInstalled a => PackageIndex a
541
                  -> [UnitId]
542
                  -> Either (PackageIndex a)
543
                            [(a, [UnitId])]
544
dependencyClosure index pkgids0 = case closure mempty [] pkgids0 of
545 546
  (completed, []) -> Left completed
  (completed, _)  -> Right (brokenPackages completed)
547
 where
548
    closure completed failed []             = (completed, failed)
549
    closure completed failed (pkgid:pkgids) = case lookupUnitId index pkgid of
550
      Nothing   -> closure completed (pkgid:failed) pkgids
551
      Just pkg  -> case lookupUnitId completed (installedUnitId pkg) of
552 553
        Just _  -> closure completed  failed pkgids
        Nothing -> closure completed' failed pkgids'
Duncan Coutts's avatar
Duncan Coutts committed
554
          where completed' = insert pkg completed
555
                pkgids'    = installedDepends pkg ++ pkgids
556

557
-- | Takes the transitive closure of the packages reverse dependencies.
558
--
Duncan Coutts's avatar
Duncan Coutts committed
559
-- * The given 'PackageId's must be in the index.
560
--
561
reverseDependencyClosure :: PackageInstalled a => PackageIndex a
562
                         -> [UnitId]
563
                         -> [a]
564
reverseDependencyClosure index =
565 566 567 568
    map vertexToPkg
  . concatMap Tree.flatten
  . Graph.dfs reverseDepGraph
  . map (fromMaybe noSuchPkgId . pkgIdToVertex)
569

570
  where
571
    (depGraph, vertexToPkg, pkgIdToVertex) = dependencyGraph index
572 573 574
    reverseDepGraph = Graph.transposeG depGraph
    noSuchPkgId = error "reverseDependencyClosure: package is not in the graph"

575
topologicalOrder :: PackageInstalled a => PackageIndex a -> [a]
576 577 578 579 580
topologicalOrder index = map toPkgId
                       . Graph.topSort
                       $ graph
  where (graph, toPkgId, _) = dependencyGraph index

581
reverseTopologicalOrder :: PackageInstalled a => PackageIndex a -> [a]
582 583 584 585 586 587 588 589 590 591 592
reverseTopologicalOrder index = map toPkgId
                              . Graph.topSort
                              . Graph.transposeG
                              $ graph
  where (graph, toPkgId, _) = dependencyGraph index

-- | Builds a graph of the package dependencies.
--
-- Dependencies on other packages that are not in the index are discarded.
-- You can check if there are any such dependencies with 'brokenPackages'.
--
593
dependencyGraph :: PackageInstalled a => PackageIndex a
594
                -> (Graph.Graph,
595
                    Graph.Vertex -> a,
596
                    UnitId -> Maybe Graph.Vertex)
597
dependencyGraph index = (graph, vertex_to_pkg, id_to_vertex)
598 599
  where
    graph = Array.listArray bounds
600
              [ [ v | Just v <- map id_to_vertex (installedDepends pkg) ]
601
              | pkg <- pkgs ]
602

Duncan Coutts's avatar
Duncan Coutts committed
603
    pkgs             = sortBy (comparing packageId) (allPackages index)
604
    vertices         = zip (map installedUnitId pkgs) [0..]
605
    vertex_map       = Map.fromList vertices
606
    id_to_vertex pid = Map.lookup pid vertex_map
607 608

    vertex_to_pkg vertex = pkgTable ! vertex
609 610 611 612 613

    pkgTable   = Array.listArray bounds pkgs
    topBound = length pkgs - 1
    bounds = (0, topBound)

614 615 616 617 618 619 620 621 622 623
-- | Given a package index where we assume we want to use all the packages
-- (use 'dependencyClosure' if you need to get such a index subset) find out
-- if the dependencies within it use consistent versions of each package.
-- Return all cases where multiple packages depend on different versions of
-- some other package.
--
-- Each element in the result is a package name along with the packages that
-- depend on it and the versions they require. These are guaranteed to be
-- distinct.
--
624
dependencyInconsistencies :: PackageInstalled a => PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
625
                          -> [(PackageName, [(PackageId, Version)])]
626
dependencyInconsistencies index =
627 628 629 630 631 632 633 634 635 636 637 638
  [ (name, [ (pid,packageVersion dep) | (dep,pids) <- uses, pid <- pids])
  | (name, ipid_map) <- Map.toList inverseIndex
  , let uses = Map.elems ipid_map
  , reallyIsInconsistent (map fst uses) ]

  where -- for each PackageName,
        --   for each package with that name,
        --     the InstalledPackageInfo and the package Ids of packages
        --     that depend on it.
        inverseIndex = Map.fromListWith (Map.unionWith (\(a,b) (_,b') -> (a,b++b')))
          [ (packageName dep,
             Map.fromList [(ipid,(dep,[packageId pkg]))])
Duncan Coutts's avatar
Duncan Coutts committed
639
          | pkg <- allPackages index
640
          , ipid <- installedDepends pkg
641
          , Just dep <- [lookupUnitId index ipid]
642 643
          ]

644 645 646 647 648
        -- Added in 991e52a474e2b8280432257c1771dc474a320a30,
        -- this is a special case to handle the base 3 compatibility
        -- package which shipped with GHC 6.10 and GHC 6.12
        -- (it was removed in GHC 7.0).  Remove this when GHC 6.12
        -- goes out of our support window.
649
        reallyIsInconsistent :: PackageInstalled a => [a] -> Bool
650 651 652
        reallyIsInconsistent []       = False
        reallyIsInconsistent [_p]     = False
        reallyIsInconsistent [p1, p2] =
653 654
          let pid1 = installedUnitId p1
              pid2 = installedUnitId p2
655 656
          in pid1 `notElem` installedDepends p2
          && pid2 `notElem` installedDepends p1
657
        reallyIsInconsistent _ = True
Duncan Coutts's avatar
Duncan Coutts committed
658

Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
659 660 661 662
-- | A rough approximation of GHC's module finder, takes a
-- 'InstalledPackageIndex' and turns it into a map from module names to their
-- source packages.  It's used to initialize the @build-deps@ field in @cabal
-- init@.
663
moduleNameIndex :: InstalledPackageIndex -> Map ModuleName [IPI.InstalledPackageInfo]
Duncan Coutts's avatar
Duncan Coutts committed
664
moduleNameIndex index =
665 666
  Map.fromListWith (++) $ do
    pkg <- allPackages index
667
    IPI.ExposedModule m reexport <- IPI.exposedModules pkg
668 669
    case reexport of
        Nothing -> return (m, [pkg])
670 671
        Just (OpenModuleVar _) -> []
        Just (OpenModule _ m') | m == m'   -> []
672
                                | otherwise -> return (m', [pkg])
673 674 675 676 677
        -- The heuristic is this: we want to prefer the original package
        -- which originally exported a module.  However, if a reexport
        -- also *renamed* the module (m /= m'), then we have to use the
        -- downstream package, since the upstream package has the wrong
        -- module name!