----------------------------------------------------------------------------- -- | -- Module : Distribution.Client.Dependency -- Copyright : (c) David Himmelstrup 2005, -- Bjorn Bringert 2007 -- Duncan Coutts 2008 -- License : BSD-like -- -- Maintainer : cabal-devel@gmail.com -- Stability : provisional -- Portability : portable -- -- Top level interface to dependency resolution. ----------------------------------------------------------------------------- module Distribution.Client.Dependency ( -- * The main package dependency resolver chooseSolver, resolveDependencies, Progress(..), foldProgress, -- * Alternate, simple resolver that does not do dependencies recursively resolveWithoutDependencies, -- * Constructing resolver policies DepResolverParams(..), PackageConstraint(..), PackagesPreferenceDefault(..), PackagePreference(..), InstalledPreference(..), -- ** Standard policy standardInstallPolicy, PackageSpecifier(..), -- ** Sandbox policy applySandboxInstallPolicy, -- ** Extra policy options dontUpgradeNonUpgradeablePackages, hideBrokenInstalledPackages, upgradeDependencies, reinstallTargets, -- ** Policy utils addConstraints, addPreferences, setPreferenceDefault, setReorderGoals, setIndependentGoals, setAvoidReinstalls, setShadowPkgs, setStrongFlags, setMaxBackjumps, addSourcePackages, hideInstalledPackagesSpecificByInstalledPackageId, hideInstalledPackagesSpecificBySourcePackageId, hideInstalledPackagesAllVersions, removeUpperBounds ) where import Distribution.Client.Dependency.TopDown ( topDownResolver ) import Distribution.Client.Dependency.Modular ( modularResolver, SolverConfig(..) ) import qualified Distribution.Client.PackageIndex as PackageIndex import Distribution.Simple.PackageIndex (InstalledPackageIndex) import qualified Distribution.Simple.PackageIndex as InstalledPackageIndex import qualified Distribution.Client.InstallPlan as InstallPlan import Distribution.Client.InstallPlan (InstallPlan) import Distribution.Client.Types ( SourcePackageDb(SourcePackageDb), SourcePackage(..) , ConfiguredPackage(..), ConfiguredId(..), enableStanzas ) import Distribution.Client.Dependency.Types ( PreSolver(..), Solver(..), DependencyResolver, ResolverPackage(..) , PackageConstraint(..), showPackageConstraint , LabeledPackageConstraint(..), unlabelPackageConstraint , ConstraintSource(..), showConstraintSource , AllowNewer(..), PackagePreferences(..), InstalledPreference(..) , PackagesPreferenceDefault(..) , Progress(..), foldProgress ) import Distribution.Client.Sandbox.Types ( SandboxPackageInfo(..) ) import Distribution.Client.Targets import Distribution.Client.ComponentDeps (ComponentDeps) import qualified Distribution.Client.ComponentDeps as CD import qualified Distribution.InstalledPackageInfo as Installed import Distribution.Package ( PackageName(..), PackageIdentifier(PackageIdentifier), PackageId , Package(..), packageName, packageVersion , InstalledPackageId, Dependency(Dependency)) import qualified Distribution.PackageDescription as PD ( PackageDescription(..), Library(..), Executable(..) , TestSuite(..), Benchmark(..), SetupBuildInfo(..) , GenericPackageDescription(..), CondTree , Flag(flagName), FlagName(..) ) import Distribution.PackageDescription (BuildInfo(targetBuildDepends)) import Distribution.PackageDescription.Configuration ( mapCondTree, finalizePackageDescription ) import Distribution.Client.PackageUtils ( externalBuildDepends ) import Distribution.Version ( VersionRange, anyVersion, thisVersion, withinRange , removeUpperBound, simplifyVersionRange ) import Distribution.Compiler ( CompilerInfo(..) ) import Distribution.System ( Platform ) import Distribution.Client.Utils ( duplicates, duplicatesBy, mergeBy, MergeResult(..) ) import Distribution.Simple.Utils ( comparing, warn, info ) import Distribution.Text ( display ) import Distribution.Verbosity ( Verbosity ) import Data.List ( foldl', sort, sortBy, nubBy, maximumBy, intercalate ) import Data.Function (on) import Data.Maybe (fromMaybe) import qualified Data.Map as Map import qualified Data.Set as Set import Data.Set (Set) import Control.Exception ( assert ) -- ------------------------------------------------------------ -- * High level planner policy -- ------------------------------------------------------------ -- | The set of parameters to the dependency resolver. These parameters are -- relatively low level but many kinds of high level policies can be -- implemented in terms of adjustments to the parameters. -- data DepResolverParams = DepResolverParams { depResolverTargets :: [PackageName], depResolverConstraints :: [LabeledPackageConstraint], depResolverPreferences :: [PackagePreference], depResolverPreferenceDefault :: PackagesPreferenceDefault, depResolverInstalledPkgIndex :: InstalledPackageIndex, depResolverSourcePkgIndex :: PackageIndex.PackageIndex SourcePackage, depResolverReorderGoals :: Bool, depResolverIndependentGoals :: Bool, depResolverAvoidReinstalls :: Bool, depResolverShadowPkgs :: Bool, depResolverStrongFlags :: Bool, depResolverMaxBackjumps :: Maybe Int } showDepResolverParams :: DepResolverParams -> String showDepResolverParams p = "targets: " ++ intercalate ", " (map display (depResolverTargets p)) ++ "\nconstraints: " ++ concatMap (("\n " ++) . showLabeledConstraint) (depResolverConstraints p) ++ "\npreferences: " ++ concatMap (("\n " ++) . showPackagePreference) (depResolverPreferences p) ++ "\nstrategy: " ++ show (depResolverPreferenceDefault p) where showLabeledConstraint :: LabeledPackageConstraint -> String showLabeledConstraint (LabeledPackageConstraint pc src) = showPackageConstraint pc ++ " (" ++ showConstraintSource src ++ ")" -- | A package selection preference for a particular package. -- -- Preferences are soft constraints that the dependency resolver should try to -- respect where possible. It is not specified if preferences on some packages -- are more important than others. -- data PackagePreference = -- | A suggested constraint on the version number. PackageVersionPreference PackageName VersionRange -- | If we prefer versions of packages that are already installed. | PackageInstalledPreference PackageName InstalledPreference -- | Provide a textual representation of a package preference -- for debugging purposes. -- showPackagePreference :: PackagePreference -> String showPackagePreference (PackageVersionPreference pn vr) = display pn ++ " " ++ display (simplifyVersionRange vr) showPackagePreference (PackageInstalledPreference pn ip) = display pn ++ " " ++ show ip basicDepResolverParams :: InstalledPackageIndex -> PackageIndex.PackageIndex SourcePackage -> DepResolverParams basicDepResolverParams installedPkgIndex sourcePkgIndex = DepResolverParams { depResolverTargets = [], depResolverConstraints = [], depResolverPreferences = [], depResolverPreferenceDefault = PreferLatestForSelected, depResolverInstalledPkgIndex = installedPkgIndex, depResolverSourcePkgIndex = sourcePkgIndex, depResolverReorderGoals = False, depResolverIndependentGoals = False, depResolverAvoidReinstalls = False, depResolverShadowPkgs = False, depResolverStrongFlags = False, depResolverMaxBackjumps = Nothing } addTargets :: [PackageName] -> DepResolverParams -> DepResolverParams addTargets extraTargets params = params { depResolverTargets = extraTargets ++ depResolverTargets params } addConstraints :: [LabeledPackageConstraint] -> DepResolverParams -> DepResolverParams addConstraints extraConstraints params = params { depResolverConstraints = extraConstraints ++ depResolverConstraints params } addPreferences :: [PackagePreference] -> DepResolverParams -> DepResolverParams addPreferences extraPreferences params = params { depResolverPreferences = extraPreferences ++ depResolverPreferences params } setPreferenceDefault :: PackagesPreferenceDefault -> DepResolverParams -> DepResolverParams setPreferenceDefault preferenceDefault params = params { depResolverPreferenceDefault = preferenceDefault } setReorderGoals :: Bool -> DepResolverParams -> DepResolverParams setReorderGoals b params = params { depResolverReorderGoals = b } setIndependentGoals :: Bool -> DepResolverParams -> DepResolverParams setIndependentGoals b params = params { depResolverIndependentGoals = b } setAvoidReinstalls :: Bool -> DepResolverParams -> DepResolverParams setAvoidReinstalls b params = params { depResolverAvoidReinstalls = b } setShadowPkgs :: Bool -> DepResolverParams -> DepResolverParams setShadowPkgs b params = params { depResolverShadowPkgs = b } setStrongFlags :: Bool -> DepResolverParams -> DepResolverParams setStrongFlags b params = params { depResolverStrongFlags = b } setMaxBackjumps :: Maybe Int -> DepResolverParams -> DepResolverParams setMaxBackjumps n params = params { depResolverMaxBackjumps = n } -- | Some packages are specific to a given compiler version and should never be -- upgraded. dontUpgradeNonUpgradeablePackages :: DepResolverParams -> DepResolverParams dontUpgradeNonUpgradeablePackages params = addConstraints extraConstraints params where extraConstraints = [ LabeledPackageConstraint (PackageConstraintInstalled pkgname) ConstraintSourceNonUpgradeablePackage | all (/=PackageName "base") (depResolverTargets params) , pkgname <- map PackageName [ "base", "ghc-prim", "integer-gmp" , "integer-simple" ] , isInstalled pkgname ] -- TODO: the top down resolver chokes on the base constraints -- below when there are no targets and thus no dep on base. -- Need to refactor constraints separate from needing packages. isInstalled = not . null . InstalledPackageIndex.lookupPackageName (depResolverInstalledPkgIndex params) addSourcePackages :: [SourcePackage] -> DepResolverParams -> DepResolverParams addSourcePackages pkgs params = params { depResolverSourcePkgIndex = foldl (flip PackageIndex.insert) (depResolverSourcePkgIndex params) pkgs } hideInstalledPackagesSpecificByInstalledPackageId :: [InstalledPackageId] -> DepResolverParams -> DepResolverParams hideInstalledPackagesSpecificByInstalledPackageId pkgids params = --TODO: this should work using exclude constraints instead params { depResolverInstalledPkgIndex = foldl' (flip InstalledPackageIndex.deleteInstalledPackageId) (depResolverInstalledPkgIndex params) pkgids } hideInstalledPackagesSpecificBySourcePackageId :: [PackageId] -> DepResolverParams -> DepResolverParams hideInstalledPackagesSpecificBySourcePackageId pkgids params = --TODO: this should work using exclude constraints instead params { depResolverInstalledPkgIndex = foldl' (flip InstalledPackageIndex.deleteSourcePackageId) (depResolverInstalledPkgIndex params) pkgids } hideInstalledPackagesAllVersions :: [PackageName] -> DepResolverParams -> DepResolverParams hideInstalledPackagesAllVersions pkgnames params = --TODO: this should work using exclude constraints instead params { depResolverInstalledPkgIndex = foldl' (flip InstalledPackageIndex.deletePackageName) (depResolverInstalledPkgIndex params) pkgnames } hideBrokenInstalledPackages :: DepResolverParams -> DepResolverParams hideBrokenInstalledPackages params = hideInstalledPackagesSpecificByInstalledPackageId pkgids params where pkgids = map Installed.installedPackageId . InstalledPackageIndex.reverseDependencyClosure (depResolverInstalledPkgIndex params) . map (Installed.installedPackageId . fst) . InstalledPackageIndex.brokenPackages $ depResolverInstalledPkgIndex params -- | Remove upper bounds in dependencies using the policy specified by the -- 'AllowNewer' argument (all/some/none). removeUpperBounds :: AllowNewer -> DepResolverParams -> DepResolverParams removeUpperBounds allowNewer params = params { -- NB: It's important to apply 'removeUpperBounds' after -- 'addSourcePackages'. Otherwise, the packages inserted by -- 'addSourcePackages' won't have upper bounds in dependencies relaxed. depResolverSourcePkgIndex = sourcePkgIndex' } where sourcePkgIndex = depResolverSourcePkgIndex params sourcePkgIndex' = case allowNewer of AllowNewerNone -> sourcePkgIndex AllowNewerAll -> fmap relaxAllPackageDeps sourcePkgIndex AllowNewerSome pkgs -> fmap (relaxSomePackageDeps pkgs) sourcePkgIndex relaxAllPackageDeps :: SourcePackage -> SourcePackage relaxAllPackageDeps = onAllBuildDepends doRelax where doRelax (Dependency pkgName verRange) = Dependency pkgName (removeUpperBound verRange) relaxSomePackageDeps :: [PackageName] -> SourcePackage -> SourcePackage relaxSomePackageDeps pkgNames = onAllBuildDepends doRelax where doRelax d@(Dependency pkgName verRange) | pkgName `elem` pkgNames = Dependency pkgName (removeUpperBound verRange) | otherwise = d -- Walk a 'GenericPackageDescription' and apply 'f' to all 'build-depends' -- fields. onAllBuildDepends :: (Dependency -> Dependency) -> SourcePackage -> SourcePackage onAllBuildDepends f srcPkg = srcPkg' where gpd = packageDescription srcPkg pd = PD.packageDescription gpd condLib = PD.condLibrary gpd condExes = PD.condExecutables gpd condTests = PD.condTestSuites gpd condBenchs = PD.condBenchmarks gpd f' = onBuildInfo f onBuildInfo g bi = bi { targetBuildDepends = map g (targetBuildDepends bi) } onLibrary lib = lib { PD.libBuildInfo = f' $ PD.libBuildInfo lib } onExecutable exe = exe { PD.buildInfo = f' $ PD.buildInfo exe } onTestSuite tst = tst { PD.testBuildInfo = f' $ PD.testBuildInfo tst } onBenchmark bmk = bmk { PD.benchmarkBuildInfo = f' $ PD.benchmarkBuildInfo bmk } srcPkg' = srcPkg { packageDescription = gpd' } gpd' = gpd { PD.packageDescription = pd', PD.condLibrary = condLib', PD.condExecutables = condExes', PD.condTestSuites = condTests', PD.condBenchmarks = condBenchs' } pd' = pd { PD.buildDepends = map f (PD.buildDepends pd), PD.library = fmap onLibrary (PD.library pd), PD.executables = map onExecutable (PD.executables pd), PD.testSuites = map onTestSuite (PD.testSuites pd), PD.benchmarks = map onBenchmark (PD.benchmarks pd) } condLib' = fmap (onCondTree onLibrary) condLib condExes' = map (mapSnd $ onCondTree onExecutable) condExes condTests' = map (mapSnd $ onCondTree onTestSuite) condTests condBenchs' = map (mapSnd $ onCondTree onBenchmark) condBenchs mapSnd :: (a -> b) -> (c,a) -> (c,b) mapSnd = fmap onCondTree :: (a -> b) -> PD.CondTree v [Dependency] a -> PD.CondTree v [Dependency] b onCondTree g = mapCondTree g (map f) id upgradeDependencies :: DepResolverParams -> DepResolverParams upgradeDependencies = setPreferenceDefault PreferAllLatest reinstallTargets :: DepResolverParams -> DepResolverParams reinstallTargets params = hideInstalledPackagesAllVersions (depResolverTargets params) params standardInstallPolicy :: InstalledPackageIndex -> SourcePackageDb -> [PackageSpecifier SourcePackage] -> DepResolverParams standardInstallPolicy installedPkgIndex (SourcePackageDb sourcePkgIndex sourcePkgPrefs) pkgSpecifiers = addPreferences [ PackageVersionPreference name ver | (name, ver) <- Map.toList sourcePkgPrefs ] . addConstraints (concatMap pkgSpecifierConstraints pkgSpecifiers) . addTargets (map pkgSpecifierTarget pkgSpecifiers) . hideInstalledPackagesSpecificBySourcePackageId [ packageId pkg | SpecificSourcePackage pkg <- pkgSpecifiers ] . addSourcePackages [ pkg | SpecificSourcePackage pkg <- pkgSpecifiers ] $ basicDepResolverParams installedPkgIndex sourcePkgIndex applySandboxInstallPolicy :: SandboxPackageInfo -> DepResolverParams -> DepResolverParams applySandboxInstallPolicy (SandboxPackageInfo modifiedDeps otherDeps allSandboxPkgs _allDeps) params = addPreferences [ PackageInstalledPreference n PreferInstalled | n <- installedNotModified ] . addTargets installedNotModified . addPreferences [ PackageVersionPreference (packageName pkg) (thisVersion (packageVersion pkg)) | pkg <- otherDeps ] . addConstraints [ let pc = PackageConstraintVersion (packageName pkg) (thisVersion (packageVersion pkg)) in LabeledPackageConstraint pc ConstraintSourceModifiedAddSourceDep | pkg <- modifiedDeps ] . addTargets [ packageName pkg | pkg <- modifiedDeps ] . hideInstalledPackagesSpecificBySourcePackageId [ packageId pkg | pkg <- modifiedDeps ] -- We don't need to add source packages for add-source deps to the -- 'installedPkgIndex' since 'getSourcePackages' did that for us. $ params where installedPkgIds = map fst . InstalledPackageIndex.allPackagesBySourcePackageId $ allSandboxPkgs modifiedPkgIds = map packageId modifiedDeps installedNotModified = [ packageName pkg | pkg <- installedPkgIds, pkg `notElem` modifiedPkgIds ] -- ------------------------------------------------------------ -- * Interface to the standard resolver -- ------------------------------------------------------------ chooseSolver :: Verbosity -> PreSolver -> CompilerInfo -> IO Solver chooseSolver verbosity preSolver _cinfo = case preSolver of AlwaysTopDown -> do warn verbosity "Topdown solver is deprecated" return TopDown AlwaysModular -> do return Modular Choose -> do info verbosity "Choosing modular solver." return Modular runSolver :: Solver -> SolverConfig -> DependencyResolver runSolver TopDown = const topDownResolver -- TODO: warn about unsupported options runSolver Modular = modularResolver -- | Run the dependency solver. -- -- Since this is potentially an expensive operation, the result is wrapped in a -- a 'Progress' structure that can be unfolded to provide progress information, -- logging messages and the final result or an error. -- resolveDependencies :: Platform -> CompilerInfo -> Solver -> DepResolverParams -> Progress String String InstallPlan --TODO: is this needed here? see dontUpgradeNonUpgradeablePackages resolveDependencies platform comp _solver params | null (depResolverTargets params) = return (validateSolverResult platform comp indGoals []) where indGoals = depResolverIndependentGoals params resolveDependencies platform comp solver params = Step (showDepResolverParams finalparams) $ fmap (validateSolverResult platform comp indGoals) $ runSolver solver (SolverConfig reorderGoals indGoals noReinstalls shadowing strFlags maxBkjumps) platform comp installedPkgIndex sourcePkgIndex preferences constraints targets where finalparams @ (DepResolverParams targets constraints prefs defpref installedPkgIndex sourcePkgIndex reorderGoals indGoals noReinstalls shadowing strFlags maxBkjumps) = dontUpgradeNonUpgradeablePackages -- TODO: -- The modular solver can properly deal with broken -- packages and won't select them. So the -- 'hideBrokenInstalledPackages' function should be moved -- into a module that is specific to the top-down solver. . (if solver /= Modular then hideBrokenInstalledPackages else id) $ params preferences = interpretPackagesPreference (Set.fromList targets) defpref prefs -- | Give an interpretation to the global 'PackagesPreference' as -- specific per-package 'PackageVersionPreference'. -- interpretPackagesPreference :: Set PackageName -> PackagesPreferenceDefault -> [PackagePreference] -> (PackageName -> PackagePreferences) interpretPackagesPreference selected defaultPref prefs = \pkgname -> PackagePreferences (versionPref pkgname) (installPref pkgname) where versionPref pkgname = fromMaybe anyVersion (Map.lookup pkgname versionPrefs) versionPrefs = Map.fromList [ (pkgname, pref) | PackageVersionPreference pkgname pref <- prefs ] installPref pkgname = fromMaybe (installPrefDefault pkgname) (Map.lookup pkgname installPrefs) installPrefs = Map.fromList [ (pkgname, pref) | PackageInstalledPreference pkgname pref <- prefs ] installPrefDefault = case defaultPref of PreferAllLatest -> \_ -> PreferLatest PreferAllInstalled -> \_ -> PreferInstalled PreferLatestForSelected -> \pkgname -> -- When you say cabal install foo, what you really mean is, prefer the -- latest version of foo, but the installed version of everything else if pkgname `Set.member` selected then PreferLatest else PreferInstalled -- ------------------------------------------------------------ -- * Checking the result of the solver -- ------------------------------------------------------------ -- | Make an install plan from the output of the dep resolver. -- It checks that the plan is valid, or it's an error in the dep resolver. -- validateSolverResult :: Platform -> CompilerInfo -> Bool -> [ResolverPackage] -> InstallPlan validateSolverResult platform comp indepGoals pkgs = case planPackagesProblems platform comp pkgs of [] -> case InstallPlan.new indepGoals index of Right plan -> plan Left problems -> error (formatPlanProblems problems) problems -> error (formatPkgProblems problems) where index = InstalledPackageIndex.fromList (map toPlanPackage pkgs) toPlanPackage (PreExisting pkg) = InstallPlan.PreExisting pkg toPlanPackage (Configured pkg) = InstallPlan.Configured pkg formatPkgProblems = formatProblemMessage . map showPlanPackageProblem formatPlanProblems = formatProblemMessage . map InstallPlan.showPlanProblem formatProblemMessage problems = unlines $ "internal error: could not construct a valid install plan." : "The proposed (invalid) plan contained the following problems:" : problems ++ "Proposed plan:" : [InstallPlan.showPlanIndex index] data PlanPackageProblem = InvalidConfiguredPackage ConfiguredPackage [PackageProblem] showPlanPackageProblem :: PlanPackageProblem -> String showPlanPackageProblem (InvalidConfiguredPackage pkg packageProblems) = "Package " ++ display (packageId pkg) ++ " has an invalid configuration, in particular:\n" ++ unlines [ " " ++ showPackageProblem problem | problem <- packageProblems ] planPackagesProblems :: Platform -> CompilerInfo -> [ResolverPackage] -> [PlanPackageProblem] planPackagesProblems platform cinfo pkgs = [ InvalidConfiguredPackage pkg packageProblems | Configured pkg <- pkgs , let packageProblems = configuredPackageProblems platform cinfo pkg , not (null packageProblems) ] data PackageProblem = DuplicateFlag PD.FlagName | MissingFlag PD.FlagName | ExtraFlag PD.FlagName | DuplicateDeps [PackageId] | MissingDep Dependency | ExtraDep PackageId | InvalidDep Dependency PackageId showPackageProblem :: PackageProblem -> String showPackageProblem (DuplicateFlag (PD.FlagName flag)) = "duplicate flag in the flag assignment: " ++ flag showPackageProblem (MissingFlag (PD.FlagName flag)) = "missing an assignment for the flag: " ++ flag showPackageProblem (ExtraFlag (PD.FlagName flag)) = "extra flag given that is not used by the package: " ++ flag showPackageProblem (DuplicateDeps pkgids) = "duplicate packages specified as selected dependencies: " ++ intercalate ", " (map display pkgids) showPackageProblem (MissingDep dep) = "the package has a dependency " ++ display dep ++ " but no package has been selected to satisfy it." showPackageProblem (ExtraDep pkgid) = "the package configuration specifies " ++ display pkgid ++ " but (with the given flag assignment) the package does not actually" ++ " depend on any version of that package." showPackageProblem (InvalidDep dep pkgid) = "the package depends on " ++ display dep ++ " but the configuration specifies " ++ display pkgid ++ " which does not satisfy the dependency." -- | A 'ConfiguredPackage' is valid if the flag assignment is total and if -- in the configuration given by the flag assignment, all the package -- dependencies are satisfied by the specified packages. -- configuredPackageProblems :: Platform -> CompilerInfo -> ConfiguredPackage -> [PackageProblem] configuredPackageProblems platform cinfo (ConfiguredPackage pkg specifiedFlags stanzas specifiedDeps') = [ DuplicateFlag flag | ((flag,_):_) <- duplicates specifiedFlags ] ++ [ MissingFlag flag | OnlyInLeft flag <- mergedFlags ] ++ [ ExtraFlag flag | OnlyInRight flag <- mergedFlags ] ++ [ DuplicateDeps pkgs | pkgs <- CD.nonSetupDeps (fmap (duplicatesBy (comparing packageName)) specifiedDeps) ] ++ [ MissingDep dep | OnlyInLeft dep <- mergedDeps ] ++ [ ExtraDep pkgid | OnlyInRight pkgid <- mergedDeps ] ++ [ InvalidDep dep pkgid | InBoth dep pkgid <- mergedDeps , not (packageSatisfiesDependency pkgid dep) ] where specifiedDeps :: ComponentDeps [PackageId] specifiedDeps = fmap (map confSrcId) specifiedDeps' mergedFlags = mergeBy compare (sort $ map PD.flagName (PD.genPackageFlags (packageDescription pkg))) (sort $ map fst specifiedFlags) packageSatisfiesDependency (PackageIdentifier name version) (Dependency name' versionRange) = assert (name == name') $ version `withinRange` versionRange dependencyName (Dependency name _) = name mergedDeps :: [MergeResult Dependency PackageId] mergedDeps = mergeDeps requiredDeps (CD.flatDeps specifiedDeps) mergeDeps :: [Dependency] -> [PackageId] -> [MergeResult Dependency PackageId] mergeDeps required specified = let sortNubOn f = nubBy ((==) `on` f) . sortBy (compare `on` f) in mergeBy (\dep pkgid -> dependencyName dep `compare` packageName pkgid) (sortNubOn dependencyName required) (sortNubOn packageName specified) -- TODO: It would be nicer to use ComponentDeps here so we can be more -- precise in our checks. That's a bit tricky though, as this currently -- relies on the 'buildDepends' field of 'PackageDescription'. (OTOH, that -- field is deprecated and should be removed anyway.) As long as we _do_ -- use a flat list here, we have to allow for duplicates when we fold -- specifiedDeps; once we have proper ComponentDeps here we should get rid -- of the `nubOn` in `mergeDeps`. requiredDeps :: [Dependency] requiredDeps = --TODO: use something lower level than finalizePackageDescription case finalizePackageDescription specifiedFlags (const True) platform cinfo [] (enableStanzas stanzas $ packageDescription pkg) of Right (resolvedPkg, _) -> externalBuildDepends resolvedPkg ++ maybe [] PD.setupDepends (PD.setupBuildInfo resolvedPkg) Left _ -> error "configuredPackageInvalidDeps internal error" -- ------------------------------------------------------------ -- * Simple resolver that ignores dependencies -- ------------------------------------------------------------ -- | A simplistic method of resolving a list of target package names to -- available packages. -- -- Specifically, it does not consider package dependencies at all. Unlike -- 'resolveDependencies', no attempt is made to ensure that the selected -- packages have dependencies that are satisfiable or consistent with -- each other. -- -- It is suitable for tasks such as selecting packages to download for user -- inspection. It is not suitable for selecting packages to install. -- -- Note: if no installed package index is available, it is OK to pass 'mempty'. -- It simply means preferences for installed packages will be ignored. -- resolveWithoutDependencies :: DepResolverParams -> Either [ResolveNoDepsError] [SourcePackage] resolveWithoutDependencies (DepResolverParams targets constraints prefs defpref installedPkgIndex sourcePkgIndex _reorderGoals _indGoals _avoidReinstalls _shadowing _strFlags _maxBjumps) = collectEithers (map selectPackage targets) where selectPackage :: PackageName -> Either ResolveNoDepsError SourcePackage selectPackage pkgname | null choices = Left $! ResolveUnsatisfiable pkgname requiredVersions | otherwise = Right $! maximumBy bestByPrefs choices where -- Constraints requiredVersions = packageConstraints pkgname pkgDependency = Dependency pkgname requiredVersions choices = PackageIndex.lookupDependency sourcePkgIndex pkgDependency -- Preferences PackagePreferences preferredVersions preferInstalled = packagePreferences pkgname bestByPrefs = comparing $ \pkg -> (installPref pkg, versionPref pkg, packageVersion pkg) installPref = case preferInstalled of PreferLatest -> const False PreferInstalled -> not . null . InstalledPackageIndex.lookupSourcePackageId installedPkgIndex . packageId versionPref pkg = packageVersion pkg `withinRange` preferredVersions packageConstraints :: PackageName -> VersionRange packageConstraints pkgname = Map.findWithDefault anyVersion pkgname packageVersionConstraintMap packageVersionConstraintMap = let pcs = map unlabelPackageConstraint constraints in Map.fromList [ (name, range) | PackageConstraintVersion name range <- pcs ] packagePreferences :: PackageName -> PackagePreferences packagePreferences = interpretPackagesPreference (Set.fromList targets) defpref prefs collectEithers :: [Either a b] -> Either [a] [b] collectEithers = collect . partitionEithers where collect ([], xs) = Right xs collect (errs,_) = Left errs partitionEithers :: [Either a b] -> ([a],[b]) partitionEithers = foldr (either left right) ([],[]) where left a (l, r) = (a:l, r) right a (l, r) = (l, a:r) -- | Errors for 'resolveWithoutDependencies'. -- data ResolveNoDepsError = -- | A package name which cannot be resolved to a specific package. -- Also gives the constraint on the version and whether there was -- a constraint on the package being installed. ResolveUnsatisfiable PackageName VersionRange instance Show ResolveNoDepsError where show (ResolveUnsatisfiable name ver) = "There is no available version of " ++ display name ++ " that satisfies " ++ display (simplifyVersionRange ver)