PackageIndex.hs 24 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)

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

121
import Control.Exception (assert)
122
import Data.Array ((!))
ttuegel's avatar
ttuegel committed
123 124
import qualified Data.Array as Array
import qualified Data.Graph as Graph
125
import Data.List as List ( groupBy,  deleteBy, deleteFirstsBy )
ttuegel's avatar
ttuegel committed
126 127
import qualified Data.Map as Map
import qualified Data.Tree  as Tree
128 129

-- | The collection of information about packages from one or more 'PackageDB's.
130
-- These packages generally should have an instance of 'PackageInstalled'
131
--
132
-- Packages are uniquely identified in by their 'UnitId', they can
Ian D. Bollinger's avatar
Ian D. Bollinger committed
133
-- also be efficiently looked up by package name or by name and version.
134
--
135
data PackageIndex a = PackageIndex
Duncan Coutts's avatar
Duncan Coutts committed
136
  -- The primary index. Each InstalledPackageInfo record is uniquely identified
137
  -- by its UnitId.
Duncan Coutts's avatar
Duncan Coutts committed
138
  --
139
  !(Map UnitId a)
Duncan Coutts's avatar
Duncan Coutts committed
140

Ian D. Bollinger's avatar
Ian D. Bollinger committed
141
  -- This auxiliary index maps package names (case-sensitively) to all the
Duncan Coutts's avatar
Duncan Coutts committed
142 143
  -- versions and instances of that package. This allows us to find all
  -- versions satisfying a dependency.
144
  --
Duncan Coutts's avatar
Duncan Coutts committed
145 146
  -- 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
147
  -- of the same package version. These are unique by UnitId
Duncan Coutts's avatar
Duncan Coutts committed
148
  -- and are kept in preference order.
149
  --
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
150 151
  -- FIXME: Clarify what "preference order" means. Check that this invariant is
  -- preserved. See #1463 for discussion.
152
  !(Map PackageName (Map Version [a]))
153

154
  deriving (Eq, Generic, Show, Read)
ttuegel's avatar
ttuegel committed
155 156

instance Binary a => Binary (PackageIndex a)
Duncan Coutts's avatar
Duncan Coutts committed
157

158 159
-- | The default package index which contains 'InstalledPackageInfo'.  Normally
-- use this.
160
type InstalledPackageIndex = PackageIndex IPI.InstalledPackageInfo
161

162
instance HasUnitId a => Monoid (PackageIndex a) where
Duncan Coutts's avatar
Duncan Coutts committed
163
  mempty  = PackageIndex Map.empty Map.empty
164
  mappend = (<>)
165
  --save one mappend with empty in the common case:
166
  mconcat [] = mempty
167 168
  mconcat xs = foldr1 mappend xs

169
instance HasUnitId a => Semigroup (PackageIndex a) where
170 171
  (<>) = merge

172
invariant :: HasUnitId a => PackageIndex a -> Bool
Duncan Coutts's avatar
Duncan Coutts committed
173
invariant (PackageIndex pids pnames) =
174
     map installedUnitId (Map.elems pids)
175
  == sort
176
     [ assert pinstOk (installedUnitId pinst)
Duncan Coutts's avatar
Duncan Coutts committed
177 178 179
     | (pname, pvers)  <- Map.toList pnames
     , let pversOk = not (Map.null pvers)
     , (pver,  pinsts) <- assert pversOk $ Map.toList pvers
180
     , let pinsts'  = sortBy (comparing installedUnitId) pinsts
Duncan Coutts's avatar
Duncan Coutts committed
181
           pinstsOk = all (\g -> length g == 1)
182
                          (groupBy (equating installedUnitId) pinsts')
Duncan Coutts's avatar
Duncan Coutts committed
183 184 185 186 187
     , pinst           <- assert pinstsOk $ pinsts'
     , let pinstOk = packageName    pinst == pname
                  && packageVersion pinst == pver
     ]

188

189 190 191 192
--
-- * Internal helpers
--

193 194
mkPackageIndex :: HasUnitId a
               => Map UnitId a
195 196
               -> Map PackageName (Map Version [a])
               -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
197 198
mkPackageIndex pids pnames = assert (invariant index) index
  where index = PackageIndex pids pnames
199

200 201 202

--
-- * Construction
203 204
--

205
-- | Build an index out of a bunch of packages.
206
--
207
-- If there are duplicates by 'UnitId' then later ones mask earlier
Duncan Coutts's avatar
Duncan Coutts committed
208
-- ones.
209
--
210
fromList :: HasUnitId a => [a] -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
211
fromList pkgs = mkPackageIndex pids pnames
212
  where
213
    pids      = Map.fromList [ (installedUnitId pkg, pkg) | pkg <- pkgs ]
Duncan Coutts's avatar
Duncan Coutts committed
214 215 216 217 218 219 220 221 222
    pnames    =
      Map.fromList
        [ (packageName (head pkgsN), pvers)
        | pkgsN <- groupBy (equating  packageName)
                 . sortBy  (comparing packageId)
                 $ pkgs
        , let pvers =
                Map.fromList
                [ (packageVersion (head pkgsNV),
223
                   nubBy (equating installedUnitId) (reverse pkgsNV))
Duncan Coutts's avatar
Duncan Coutts committed
224 225 226
                | pkgsNV <- groupBy (equating packageVersion) pkgsN
                ]
        ]
227

228 229 230 231
--
-- * Updates
--

232 233
-- | Merge two indexes.
--
Duncan Coutts's avatar
Duncan Coutts committed
234
-- Packages from the second mask packages from the first if they have the exact
235
-- same 'UnitId'.
236
--
Duncan Coutts's avatar
Duncan Coutts committed
237 238 239 240 241
-- 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.
--
242
merge :: HasUnitId a => PackageIndex a -> PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
243
      -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
244
merge (PackageIndex pids1 pnames1) (PackageIndex pids2 pnames2) =
245
  mkPackageIndex (Map.unionWith (\_ y -> y) pids1 pids2)
Duncan Coutts's avatar
Duncan Coutts committed
246 247 248 249 250
                 (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)
251
    (\\) = deleteFirstsBy (equating installedUnitId)
252

253

Duncan Coutts's avatar
Duncan Coutts committed
254
-- | Inserts a single package into the index.
255 256 257 258
--
-- This is equivalent to (but slightly quicker than) using 'mappend' or
-- 'merge' with a singleton index.
--
259
insert :: HasUnitId a => a -> PackageIndex a -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
260 261 262
insert pkg (PackageIndex pids pnames) =
    mkPackageIndex pids' pnames'

263
  where
264
    pids'   = Map.insert (installedUnitId pkg) pkg pids
Duncan Coutts's avatar
Duncan Coutts committed
265 266 267 268 269 270 271 272 273 274 275
    pnames' = insertPackageName pnames
    insertPackageName =
      Map.insertWith' (\_ -> insertPackageVersion)
                     (packageName pkg)
                     (Map.singleton (packageVersion pkg) [pkg])

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

    insertPackageInstance pkgs =
276
      pkg : deleteBy (equating installedUnitId) pkg pkgs
Duncan Coutts's avatar
Duncan Coutts committed
277 278 279 280


-- | Removes a single installed package from the index.
--
281
deleteUnitId :: HasUnitId a
282 283
             => UnitId -> PackageIndex a
             -> PackageIndex a
284
deleteUnitId ipkgid original@(PackageIndex pids pnames) =
Duncan Coutts's avatar
Duncan Coutts committed
285 286 287 288 289
  case Map.updateLookupWithKey (\_ _ -> Nothing) ipkgid pids of
    (Nothing,     _)     -> original
    (Just spkgid, pids') -> mkPackageIndex pids'
                                          (deletePkgName spkgid pnames)

Duncan Coutts's avatar
Duncan Coutts committed
290
  where
Duncan Coutts's avatar
Duncan Coutts committed
291 292 293 294 295 296
    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
297

Duncan Coutts's avatar
Duncan Coutts committed
298
    deletePkgInstance =
299
        (\xs -> if null xs then Nothing else Just xs)
300
      . List.deleteBy (\_ pkg -> installedUnitId pkg == ipkgid) undefined
Duncan Coutts's avatar
Duncan Coutts committed
301

Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
302
-- | Backwards compatibility wrapper for Cabal pre-1.24.
303 304 305 306 307
{-# DEPRECATED deleteInstalledPackageId "Use deleteUnitId instead" #-}
deleteInstalledPackageId :: HasUnitId a
                         => UnitId -> PackageIndex a
                         -> PackageIndex a
deleteInstalledPackageId = deleteUnitId
Duncan Coutts's avatar
Duncan Coutts committed
308 309

-- | Removes all packages with this source 'PackageId' from the index.
310
--
311
deleteSourcePackageId :: HasUnitId a => PackageId -> PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
312
                      -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
313 314 315 316 317 318
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
319
                     (foldl' (flip (Map.delete . installedUnitId)) pids pkgs)
Duncan Coutts's avatar
Duncan Coutts committed
320 321 322 323 324 325 326 327 328
                     (deletePkgName pnames)
  where
    deletePkgName =
      Map.update deletePkgVersion (packageName pkgid)

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

329 330 331

-- | Removes all packages with this (case-sensitive) name from the index.
--
332
deletePackageName :: HasUnitId a => PackageName -> PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
333
                  -> PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
334 335 336 337
deletePackageName name original@(PackageIndex pids pnames) =
  case Map.lookup name pnames of
    Nothing     -> original
    Just pvers  -> mkPackageIndex
338
                     (foldl' (flip (Map.delete . installedUnitId)) pids
Duncan Coutts's avatar
Duncan Coutts committed
339 340
                             (concat (Map.elems pvers)))
                     (Map.delete name pnames)
341

Duncan Coutts's avatar
Duncan Coutts committed
342
{-
343 344
-- | Removes all packages satisfying this dependency from the index.
--
Duncan Coutts's avatar
Duncan Coutts committed
345
deleteDependency :: Dependency -> PackageIndex -> PackageIndex
346
deleteDependency (Dependency name verstionRange) =
Duncan Coutts's avatar
Duncan Coutts committed
347 348
  delete' name (\pkg -> packageVersion pkg `withinRange` verstionRange)
-}
349

350 351 352 353
--
-- * Bulk queries
--

354 355
-- | Get all the packages from the index.
--
356
allPackages :: PackageIndex a -> [a]
Duncan Coutts's avatar
Duncan Coutts committed
357
allPackages (PackageIndex pids _) = Map.elems pids
358 359 360

-- | Get all the packages from the index.
--
361
-- They are grouped by package name (case-sensitively).
362
--
363
allPackagesByName :: PackageIndex a -> [(PackageName, [a])]
Duncan Coutts's avatar
Duncan Coutts committed
364
allPackagesByName (PackageIndex _ pnames) =
365 366 367 368 369 370 371
  [ (pkgname, concat (Map.elems pvers))
  | (pkgname, pvers) <- Map.toList pnames ]

-- | Get all the packages from the index.
--
-- They are grouped by source package id (package name and version).
--
372
allPackagesBySourcePackageId :: HasUnitId a => PackageIndex a
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
373
                             -> [(PackageId, [a])]
374 375 376 377
allPackagesBySourcePackageId (PackageIndex _ pnames) =
  [ (packageId ipkg, ipkgs)
  | pvers <- Map.elems pnames
  , ipkgs@(ipkg:_) <- Map.elems pvers ]
378 379 380 381 382

--
-- * Lookups
--

383
-- | Does a lookup by unit identifier.
384
--
385
-- Since multiple package DBs mask each other by 'UnitId',
386 387
-- then we get back at most one package.
--
388
lookupUnitId :: PackageIndex a -> UnitId
389
             -> Maybe a
390 391 392 393 394 395 396 397
lookupUnitId (PackageIndex m _) uid = Map.lookup uid m

-- | Does a lookup by component identifier.  In the absence
-- of Backpack, this is just a 'lookupUnitId'.
--
lookupComponentId :: PackageIndex a -> ComponentId
                  -> Maybe a
lookupComponentId (PackageIndex m _) uid = Map.lookup (SimpleUnitId uid) m
Duncan Coutts's avatar
Duncan Coutts committed
398

Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
399
-- | Backwards compatibility for Cabal pre-1.24.
400 401 402 403 404
{-# DEPRECATED lookupInstalledPackageId "Use lookupUnitId instead" #-}
lookupInstalledPackageId :: PackageIndex a -> UnitId
                         -> Maybe a
lookupInstalledPackageId = lookupUnitId

405

Duncan Coutts's avatar
Duncan Coutts committed
406 407 408
-- | Does a lookup by source package id (name & version).
--
-- There can be multiple installed packages with the same source 'PackageId'
409
-- but different 'UnitId'. They are returned in order of
Duncan Coutts's avatar
Duncan Coutts committed
410
-- preference, with the most preferred first.
411
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
412
lookupSourcePackageId :: PackageIndex a -> PackageId -> [a]
Duncan Coutts's avatar
Duncan Coutts committed
413 414 415 416 417 418
lookupSourcePackageId (PackageIndex _ pnames) pkgid =
  case Map.lookup (packageName pkgid) pnames of
    Nothing     -> []
    Just pvers  -> case Map.lookup (packageVersion pkgid) pvers of
      Nothing   -> []
      Just pkgs -> pkgs -- in preference order
419

420 421
-- | Convenient alias of 'lookupSourcePackageId', but assuming only
-- one package per package ID.
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
422
lookupPackageId :: PackageIndex a -> PackageId -> Maybe a
423 424 425 426
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
427 428 429

-- | Does a lookup by source package name.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
430
lookupPackageName :: PackageIndex a -> PackageName
431
                  -> [(Version, [a])]
Duncan Coutts's avatar
Duncan Coutts committed
432 433 434 435 436 437 438
lookupPackageName (PackageIndex _ pnames) name =
  case Map.lookup name pnames of
    Nothing     -> []
    Just pvers  -> Map.toList pvers


-- | Does a lookup by source package name and a range of versions.
439 440 441 442
--
-- 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
443
lookupDependency :: PackageIndex a -> Dependency
444
                 -> [(Version, [a])]
Duncan Coutts's avatar
Duncan Coutts committed
445 446 447 448 449 450
lookupDependency (PackageIndex _ pnames) (Dependency name versionRange) =
  case Map.lookup name pnames of
    Nothing    -> []
    Just pvers -> [ entry
                  | entry@(ver, _) <- Map.toList pvers
                  , ver `withinRange` versionRange ]
451 452 453 454

--
-- * Case insensitive name lookups
--
455 456 457

-- | Does a case-insensitive search by package name.
--
Ian D. Bollinger's avatar
Ian D. Bollinger committed
458
-- If there is only one package that compares case-insensitively to this name
459
-- then the search is unambiguous and we get back all versions of that package.
Ian D. Bollinger's avatar
Ian D. Bollinger committed
460
-- If several match case-insensitively but one matches exactly then it is also
461 462
-- unambiguous.
--
Ian D. Bollinger's avatar
Ian D. Bollinger committed
463
-- If however several match case-insensitively and none match exactly then we
464 465 466 467
-- 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
468
searchByName :: PackageIndex a -> String -> SearchResult [a]
Duncan Coutts's avatar
Duncan Coutts committed
469 470
searchByName (PackageIndex _ pnames) name =
  case [ pkgs | pkgs@(PackageName name',_) <- Map.toList pnames
471
              , lowercase name' == lname ] of
Duncan Coutts's avatar
Duncan Coutts committed
472 473 474 475 476
    []               -> None
    [(_,pvers)]      -> Unambiguous (concat (Map.elems pvers))
    pkgss            -> case find ((PackageName name==) . fst) pkgss of
      Just (_,pvers) -> Unambiguous (concat (Map.elems pvers))
      Nothing        -> Ambiguous (map (concat . Map.elems . snd) pkgss)
477
  where lname = lowercase name
478 479 480 481 482 483 484

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
485
searchByNameSubstring :: PackageIndex a -> String -> [a]
Duncan Coutts's avatar
Duncan Coutts committed
486
searchByNameSubstring (PackageIndex _ pnames) searchterm =
487
  [ pkg
Duncan Coutts's avatar
Duncan Coutts committed
488
  | (PackageName name, pvers) <- Map.toList pnames
489
  , lsearchterm `isInfixOf` lowercase name
Duncan Coutts's avatar
Duncan Coutts committed
490
  , pkgs <- Map.elems pvers
491
  , pkg <- pkgs ]
492
  where lsearchterm = lowercase searchterm
493

Duncan Coutts's avatar
Duncan Coutts committed
494 495 496 497 498 499 500 501

--
-- * Special queries
--

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

502 503 504 505 506 507 508
-- | 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.
--
509
dependencyCycles :: PackageInstalled a => PackageIndex a -> [[a]]
510
dependencyCycles index =
511 512
  [ vs | Graph.CyclicSCC vs <- Graph.stronglyConnComp adjacencyList ]
  where
513
    adjacencyList = [ (pkg, installedUnitId pkg, installedDepends pkg)
514 515 516
                    | pkg <- allPackages index ]


Duncan Coutts's avatar
Duncan Coutts committed
517
-- | All packages that have immediate dependencies that are not in the index.
518
--
519 520
-- Returns such packages along with the dependencies that they're missing.
--
Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
521
brokenPackages :: PackageInstalled a => PackageIndex a
522
               -> [(a, [UnitId])]
523
brokenPackages index =
524
  [ (pkg, missing)
Duncan Coutts's avatar
Duncan Coutts committed
525
  | pkg  <- allPackages index
526
  , let missing = [ pkg' | pkg' <- installedDepends pkg
527
                         , isNothing (lookupUnitId index pkg') ]
528 529
  , not (null missing) ]

530
-- | Tries to take the transitive closure of the package dependencies.
531
--
532
-- If the transitive closure is complete then it returns that subset of the
533 534 535
-- 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
536
-- the original given 'PackageId's do not occur in the index.
537
--
538
dependencyClosure :: PackageInstalled a => PackageIndex a
539
                  -> [UnitId]
540
                  -> Either (PackageIndex a)
541
                            [(a, [UnitId])]
542
dependencyClosure index pkgids0 = case closure mempty [] pkgids0 of
543 544
  (completed, []) -> Left completed
  (completed, _)  -> Right (brokenPackages completed)
545
 where
546
    closure completed failed []             = (completed, failed)
547
    closure completed failed (pkgid:pkgids) = case lookupUnitId index pkgid of
548
      Nothing   -> closure completed (pkgid:failed) pkgids
549
      Just pkg  -> case lookupUnitId completed (installedUnitId pkg) of
550 551
        Just _  -> closure completed  failed pkgids
        Nothing -> closure completed' failed pkgids'
Duncan Coutts's avatar
Duncan Coutts committed
552
          where completed' = insert pkg completed
553
                pkgids'    = installedDepends pkg ++ pkgids
554

555
-- | Takes the transitive closure of the packages reverse dependencies.
556
--
Duncan Coutts's avatar
Duncan Coutts committed
557
-- * The given 'PackageId's must be in the index.
558
--
559
reverseDependencyClosure :: PackageInstalled a => PackageIndex a
560
                         -> [UnitId]
561
                         -> [a]
562
reverseDependencyClosure index =
563 564 565 566
    map vertexToPkg
  . concatMap Tree.flatten
  . Graph.dfs reverseDepGraph
  . map (fromMaybe noSuchPkgId . pkgIdToVertex)
567

568
  where
569
    (depGraph, vertexToPkg, pkgIdToVertex) = dependencyGraph index
570 571 572
    reverseDepGraph = Graph.transposeG depGraph
    noSuchPkgId = error "reverseDependencyClosure: package is not in the graph"

573
topologicalOrder :: PackageInstalled a => PackageIndex a -> [a]
574 575 576 577 578
topologicalOrder index = map toPkgId
                       . Graph.topSort
                       $ graph
  where (graph, toPkgId, _) = dependencyGraph index

579
reverseTopologicalOrder :: PackageInstalled a => PackageIndex a -> [a]
580 581 582 583 584 585 586 587 588 589 590
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'.
--
591
dependencyGraph :: PackageInstalled a => PackageIndex a
592
                -> (Graph.Graph,
593
                    Graph.Vertex -> a,
594
                    UnitId -> Maybe Graph.Vertex)
595
dependencyGraph index = (graph, vertex_to_pkg, id_to_vertex)
596 597
  where
    graph = Array.listArray bounds
598
              [ [ v | Just v <- map id_to_vertex (installedDepends pkg) ]
599
              | pkg <- pkgs ]
600

Duncan Coutts's avatar
Duncan Coutts committed
601
    pkgs             = sortBy (comparing packageId) (allPackages index)
602
    vertices         = zip (map installedUnitId pkgs) [0..]
603
    vertex_map       = Map.fromList vertices
604
    id_to_vertex pid = Map.lookup pid vertex_map
605 606

    vertex_to_pkg vertex = pkgTable ! vertex
607 608 609 610 611

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

612 613 614 615 616 617 618 619 620 621
-- | 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.
--
622
dependencyInconsistencies :: PackageInstalled a => PackageIndex a
Duncan Coutts's avatar
Duncan Coutts committed
623
                          -> [(PackageName, [(PackageId, Version)])]
624
dependencyInconsistencies index =
625 626 627 628 629 630 631 632 633 634 635 636
  [ (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
637
          | pkg <- allPackages index
638
          , ipid <- installedDepends pkg
639
          , Just dep <- [lookupUnitId index ipid]
640 641
          ]

642 643 644 645 646
        -- 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.
647
        reallyIsInconsistent :: PackageInstalled a => [a] -> Bool
648 649 650
        reallyIsInconsistent []       = False
        reallyIsInconsistent [_p]     = False
        reallyIsInconsistent [p1, p2] =
651 652
          let pid1 = installedUnitId p1
              pid2 = installedUnitId p2
653 654
          in pid1 `notElem` installedDepends p2
          && pid2 `notElem` installedDepends p1
655
        reallyIsInconsistent _ = True
Duncan Coutts's avatar
Duncan Coutts committed
656

Mikhail Glushenkov's avatar
Mikhail Glushenkov committed
657 658 659 660
-- | 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@.
661
moduleNameIndex :: InstalledPackageIndex -> Map ModuleName [IPI.InstalledPackageInfo]
Duncan Coutts's avatar
Duncan Coutts committed
662
moduleNameIndex index =
663 664
  Map.fromListWith (++) $ do
    pkg <- allPackages index
665
    IPI.ExposedModule m reexport <- IPI.exposedModules pkg
666 667
    case reexport of
        Nothing -> return (m, [pkg])
Edward Z. Yang's avatar
Edward Z. Yang committed
668 669
        Just (Module _ m') | m == m'   -> []
                           | otherwise -> return (m', [pkg])
670 671 672 673 674
        -- 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!