diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,13 @@ +# Revision history for distribution-nixpkgs + +## 1.6.0 + +* `Distribution.Nixpkgs.PackageMap` + * `readNixpkgPackageMap`: instead of a list of arguments to pass to + `nix-env`, take path to nixpkgs and an optional nix expression + to pass to it as arguments. + * `readNixpkgPackageMap`: populate `PackageMap` with *all* attribute + paths that point to derivations instead of just one per derivation. + This fixes `resolve` not finding certain identifiers if there were + two attributes pointing to the same derivation in nixpkgs. See also + [#9](https://github.com/NixOS/distribution-nixpkgs/issues/9). diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,4 @@ +# distribution-nixpkgs + +[![hackage release](https://img.shields.io/hackage/v/distribution-nixpkgs.svg?label=hackage)](http://hackage.haskell.org/package/distribution-nixpkgs) +[![stackage LTS package](http://stackage.org/package/distribution-nixpkgs/badge/lts)](http://stackage.org/lts/package/distribution-nixpkgs) diff --git a/derivation-attr-paths.nix b/derivation-attr-paths.nix new file mode 100644 --- /dev/null +++ b/derivation-attr-paths.nix @@ -0,0 +1,42 @@ +{ nixpkgsPath ? +, nixpkgsArgs ? {} +}@args: + +let + pkgs = import nixpkgsPath nixpkgsArgs; + + inherit (pkgs) lib; + + /* Condition for us to recurse: + Either we are at the top-level or + recurseForDerivations is true. + + Type :: list any -> any -> bool + */ + recurseInto = path: x: path == [] || + (lib.isAttrs x && (x.recurseForDerivations or false)); + + /* Takes the nixpkgs set and returns all attribute paths + to reachable derivations within it as a list of lists of + strings. + + Type :: attrs -> list (list string) + */ + derivationPaths = + let + go = path: x: + let + inherit (builtins.tryEval x) + value + success + ; + in + if !success then [] + else if lib.isDerivation value then [ + path + ] else if recurseInto path x then lib.concatLists ( + lib.mapAttrsToList (n: go (path ++ [ n ])) x + ) else []; + in go []; +in + derivationPaths pkgs diff --git a/distribution-nixpkgs.cabal b/distribution-nixpkgs.cabal --- a/distribution-nixpkgs.cabal +++ b/distribution-nixpkgs.cabal @@ -1,20 +1,23 @@ name: distribution-nixpkgs -version: 1.5.0 +version: 1.6.0 synopsis: Types and functions to manipulate the Nixpkgs distribution description: Types and functions to represent, query, and manipulate the Nixpkgs distribution. license: BSD3 license-file: LICENSE maintainer: Peter Simons -tested-with: GHC == 8.0.2 || == 8.2.2 || == 8.4.4 || == 8.6.5 || == 8.8.4 || == 8.10.4 +tested-with: GHC == 8.6.5 || == 8.8.4 || == 8.10.4 || == 9.0.1 category: Distribution, Nix -homepage: https://github.com/peti/distribution-nixpkgs -bug-reports: https://github.com/peti/distribution-nixpkgs/issues +homepage: https://github.com/NixOS/distribution-nixpkgs +bug-reports: https://github.com/NixOS/distribution-nixpkgs/issues build-type: Simple cabal-version: >= 1.10 +data-files: derivation-attr-paths.nix +extra-source-files: CHANGELOG.md + README.md source-repository head type: git - location: https://github.com/peti/distribution-nixpkgs + location: https://github.com/NixOS/distribution-nixpkgs library exposed-modules: Distribution.Nixpkgs.Hashes @@ -22,6 +25,7 @@ Distribution.Nixpkgs.Meta Distribution.Nixpkgs.PackageMap Language.Nix.PrettyPrinting + other-modules: Paths_distribution_nixpkgs hs-source-dirs: src build-depends: base > 4.2 && < 5 , Cabal >= 2.4 @@ -35,7 +39,6 @@ , process , split default-language: Haskell2010 - default-extensions: MonadFailDesugaring other-extensions: CPP TemplateHaskell RecordWildCards diff --git a/src/Distribution/Nixpkgs/License.hs b/src/Distribution/Nixpkgs/License.hs --- a/src/Distribution/Nixpkgs/License.hs +++ b/src/Distribution/Nixpkgs/License.hs @@ -2,8 +2,8 @@ {- | Known licenses in Nix expressions are represented using the - attributes defined in @pkgs\/lib\/licenses.nix@, and unknown licenses - are represented as a literal string. + attributes defined in nixpkgs' @lib\/licenses.nix@, and + unknown licenses are represented as a literal string. -} module Distribution.Nixpkgs.License ( License(..) ) where @@ -14,27 +14,28 @@ import Language.Nix.PrettyPrinting -- | The representation for licenses used in Nix derivations. Known --- licenses are Nix expressions -- such as @lib.licenses.bsd3@ --- --, so their exact \"name\" is not generally known, because the path --- to @lib@ depends on the context defined in the expression. In --- Cabal expressions, for example, the BSD3 license would have to be +-- licenses are Nix expressions — such as @lib.licenses.bsd3@ —, +-- so their exact name is not generally known, because the path +-- to @lib@ depends on the context defined in the expression. +-- +-- In Cabal expressions, for example, the BSD3 license would have to be -- referred to as @self.lib.licenses.bsd3@. Other expressions, --- however, use different paths to the @licenses@ record. Because of tat +-- however, use different paths to the @licenses@ record. Because of that -- situation, the library cannot provide an abstract data type that --- encompasses all known licenses. Instead, the @License@ type just --- distinguishes references to known and unknown licenses. The --- difference between the two is in the way they are pretty-printed: +-- encompasses all known licenses. -- --- > > putStrLn (display (Known "lib.license.gpl2")) --- > lib.license.gpl2 --- > --- > > putStrLn (display (Unknown (Just "GPL"))) --- > "GPL" --- > --- > > putStrLn (display (Unknown Nothing)) --- > "unknown" +-- Instead, the @License@ type just distinguishes references to known +-- and unknown licenses. The difference between the two is in the way +-- they are pretty-printed: -- --- Note that the "Text" instance definition provides pretty-printing, +-- >>> putStrLn (prettyShow (Known "lib.license.gpl2")) +-- lib.license.gpl2 +-- >>> putStrLn (prettyShow (Unknown (Just "GPL"))) +-- "GPL" +-- >>> putStrLn (prettyShow (Unknown Nothing)) +-- "unknown" +-- +-- Note that the 'Pretty' instance definition provides pretty-printing, -- but no parsing as of now! data License = Known String diff --git a/src/Distribution/Nixpkgs/Meta.hs b/src/Distribution/Nixpkgs/Meta.hs --- a/src/Distribution/Nixpkgs/Meta.hs +++ b/src/Distribution/Nixpkgs/Meta.hs @@ -76,10 +76,7 @@ renderPlatforms :: String -> Set Platform -> Doc renderPlatforms field ps | Set.null ps = sep [ text field <+> equals <+> text "lib.platforms.none" <> semi ] - | otherwise = sep [ text field <+> equals <+> lbrack - , nest 2 $ fsep $ map text (toAscList (Set.map fromCabalPlatform ps)) - , rbrack <> semi - ] + | otherwise = setattr field mempty $ Set.map fromCabalPlatform ps nullMeta :: Meta nullMeta = Meta diff --git a/src/Distribution/Nixpkgs/PackageMap.hs b/src/Distribution/Nixpkgs/PackageMap.hs --- a/src/Distribution/Nixpkgs/PackageMap.hs +++ b/src/Distribution/Nixpkgs/PackageMap.hs @@ -1,3 +1,4 @@ +-- | Build a lookup table from package identifiers to full attribute paths in nixpkgs. module Distribution.Nixpkgs.PackageMap ( PackageMap, readNixpkgPackageMap , resolve @@ -7,45 +8,78 @@ import qualified Data.Aeson as JSON import qualified Data.ByteString.Lazy as LBS import Data.Function -import Data.List as List -import Data.List.Split +import Data.List (minimumBy) import Data.Map.Strict ( Map ) import qualified Data.Map.Strict as Map import Data.Maybe import Data.Set ( Set ) import qualified Data.Set as Set import Language.Nix +import Paths_distribution_nixpkgs (getDataFileName) import System.Process type PackageMap = Map Identifier (Set Path) -readNixpkgPackageMap :: [String] -> IO PackageMap -readNixpkgPackageMap = fmap identifierSet2PackageMap . readNixpkgSet +-- | Evaluate nixpkgs at a given (nix) path and build a 'Map' +-- keeping track of all 'Path's that end in a given 'Identifier' +-- and evaluate to a derivation. +-- This can be used to find an attribute 'Path' for an arbitrary +-- package name using 'resolve'. +-- +-- Note: Evaluation of nixpkgs is very expensive (takes multiple +-- seconds), so cache the result of this function if possible. +-- +-- >>> readNixpkgPackageMap "" (Just "{ config = { allowAliases = false; }; }") +-- fromList [ … ] +readNixpkgPackageMap :: String + -- ^ Path to nixpkgs, must be a valid nix path + -- (absolute, relative or @NIX_PATH@ lookup) + -> Maybe String + -- ^ (Optional) argument attribute set to pass to + -- nixpkgs. Must be a valid nix attribute set. + -> IO PackageMap +readNixpkgPackageMap nixpkgsPath nixpkgsArgs = + identifierSet2PackageMap <$> readNixpkgSet nixpkgsPath nixpkgsArgs -readNixpkgSet :: [String] -> IO (Set String) -readNixpkgSet extraArgs = do - (_, Just h, _, _) <- createProcess (proc "nix-env" (["-qaP", "--json"] ++ extraArgs)) - { std_out = CreatePipe, env = Nothing } -- TODO: ensure that overrides don't screw up our results +readNixpkgSet :: String -> Maybe String -> IO (Set [String]) +readNixpkgSet nixpkgsPath nixpkgsArgs = do + pathsExpr <- getDataFileName "derivation-attr-paths.nix" + let nixInstantiate = proc "nix-instantiate" + [ "--strict" + , "--json" + , "--eval" + , pathsExpr + , "--arg", "nixpkgsPath", nixpkgsPath + , "--arg", "nixpkgsArgs", fromMaybe "{}" nixpkgsArgs + ] + (_, Just h, _, _) <- -- TODO: ensure that overrides don't screw up our results + createProcess nixInstantiate { std_out = CreatePipe, env = Nothing } buf <- LBS.hGetContents h - let pkgmap :: Either String (Map String JSON.Object) - pkgmap = JSON.eitherDecode buf - either fail (return . Map.keysSet) pkgmap + either fail return $ JSON.eitherDecode buf -identifierSet2PackageMap :: Set String -> PackageMap -identifierSet2PackageMap pkgset = foldr (uncurry insertIdentifier) Map.empty pkglist +identifierSet2PackageMap :: Set [String] -> PackageMap +identifierSet2PackageMap = foldr insertIdentifier Map.empty where - pkglist :: [(Identifier, Path)] - pkglist = mapMaybe parsePackage (Set.toList pkgset) - - insertIdentifier :: Identifier -> Path -> PackageMap -> PackageMap - insertIdentifier i = Map.insertWith Set.union i . Set.singleton + insertIdentifier :: [String] -> (PackageMap -> PackageMap) + insertIdentifier rawPath = + case parsePackage rawPath of + Nothing -> id + Just (i, p) -> Map.insertWith Set.union i $ Set.singleton p -parsePackage :: String -> Maybe (Identifier, Path) -parsePackage x | null x = error "Distribution.Nixpkgs.PackageMap.parsepackage: empty string is no valid identifier" - | xs <- splitOn "." x = if needsQuoting (head xs) - then Nothing - else Just (ident # last xs, path # map (review ident) xs) +parsePackage :: [String] -> Maybe (Identifier, Path) +parsePackage x + | null x = -- this case would be a bug in derivation-attr-paths.nix + error "Distribution.Nixpkgs.PackageMap.parsepackage: empty path is no valid identifier" + | otherwise = + if any needsQuoting x + then Nothing + else Just (ident # last x, path # map (review ident) x) +-- | Finds the shortest 'Path' in a 'PackageMap' that has the +-- given 'Identifier' as its last component. +-- +-- >>> resolve nixpkgs (ident # "pam") +-- Just (Bind (Identifier "pam") (Path [Identifier "pam"])) resolve :: PackageMap -> Identifier -> Maybe Binding resolve nixpkgs i = case Map.lookup i nixpkgs of Nothing -> Nothing diff --git a/src/Language/Nix/PrettyPrinting.hs b/src/Language/Nix/PrettyPrinting.hs --- a/src/Language/Nix/PrettyPrinting.hs +++ b/src/Language/Nix/PrettyPrinting.hs @@ -22,7 +22,7 @@ #endif import Data.Char import Data.Function -import Data.List +import Data.List (sortBy) import Data.Set ( Set ) import qualified Data.Set as Set import "pretty" Text.PrettyPrint.HughesPJClass