ghc-mod/Language/Haskell/GhcMod/GhcPkg.hs
2014-04-16 11:50:31 +09:00

104 lines
3.9 KiB
Haskell

{-# LANGUAGE BangPatterns, ScopedTypeVariables #-}
module Language.Haskell.GhcMod.GhcPkg (
ghcPkgList
, ghcPkgDbOpt
, ghcPkgDbStackOpts
, ghcDbStackOpts
, ghcDbOpt
, getSandboxDb
, getPackageDbStack
, getPackageDbPackages
) where
import Config (cProjectVersionInt) -- ghc version
import Control.Applicative ((<$>))
import Control.Exception (SomeException(..))
import qualified Control.Exception as E
import Data.Char (isSpace)
import Data.List (isPrefixOf)
import Language.Haskell.GhcMod.Types
import System.FilePath ((</>))
import System.Process (readProcess)
ghcVersion :: Int
ghcVersion = read cProjectVersionInt
-- | Get path to sandbox package db
getSandboxDb :: FilePath -- ^ Path to the cabal package root directory
-- (containing the @cabal.sandbox.config@ file)
-> IO FilePath
getSandboxDb cdir = getSandboxDbDir (cdir </> "cabal.sandbox.config")
-- | Extract the sandbox package db directory from the cabal.sandbox.config file.
-- Exception is thrown if the sandbox config file is broken.
getSandboxDbDir :: FilePath -- ^ Path to the @cabal.sandbox.config@ file
-> IO FilePath
getSandboxDbDir sconf = do
-- Be strict to ensure that an error can be caught.
!path <- extractValue . parse <$> readFile sconf
return path
where
key = "package-db:"
keyLen = length key
parse = head . filter (key `isPrefixOf`) . lines
extractValue = dropWhileEnd isSpace . dropWhile isSpace . drop keyLen
-- dropWhileEnd is not provided prior to base 4.5.0.0.
dropWhileEnd :: (a -> Bool) -> [a] -> [a]
dropWhileEnd p = foldr (\x xs -> if p x && null xs then [] else x : xs) []
-- | Get a list of packages from the global, user or cabal sandbox package
-- database.
--
-- If a sandbox exists this will return packages from the global package db
-- and the sandbox, otherwise packages from the global and user package db are
-- returned.
getPackageDbPackages :: FilePath -- ^ Project Directory (where the
-- cabal.sandbox.config file would be if it
-- exists)
-> IO [PackageBaseName]
getPackageDbPackages cdir = ghcPkgList =<< getPackageDbStack cdir
getPackageDbStack :: FilePath -- ^ Project Directory (where the
-- cabal.sandbox.config file would be if it
-- exists)
-> IO [GhcPkgDb]
getPackageDbStack cdir =
(getSandboxDb cdir >>= \db -> return [GlobalDb, PackageDb db])
`E.catch` \(_ :: SomeException) -> return [GlobalDb, UserDb]
-- | List packages in one or more ghc package stores
ghcPkgList :: [GhcPkgDb] -> IO [PackageBaseName]
ghcPkgList dbs = words <$> readProcess "ghc-pkg" opts ""
where
opts = ["--simple-output", "--names-only", "list"] ++ ghcPkgDbStackOpts dbs
-- | Get options needed to add a list of package dbs to ghc-pkg's db stack
ghcPkgDbStackOpts :: [GhcPkgDb] -- ^ Package db stack
-> [String]
ghcPkgDbStackOpts dbs = (ghcPkgDbOpt `concatMap` dbs)
-- | Get options needed to add a list of package dbs to ghc's db stack
ghcDbStackOpts :: [GhcPkgDb] -- ^ Package db stack
-> [String]
ghcDbStackOpts dbs = (ghcDbOpt `concatMap` dbs)
ghcPkgDbOpt :: GhcPkgDb -> [String]
ghcPkgDbOpt GlobalDb = ["--global"]
ghcPkgDbOpt UserDb = ["--user"]
ghcPkgDbOpt (PackageDb pkgDb)
| ghcVersion < 706 = ["--no-user-package-conf", "--package-conf=" ++ pkgDb]
| otherwise = ["--no-user-package-db", "--package-db=" ++ pkgDb]
ghcDbOpt :: GhcPkgDb -> [String]
ghcDbOpt GlobalDb
| ghcVersion < 706 = ["-global-package-conf"]
| otherwise = ["-global-package-db"]
ghcDbOpt UserDb
| ghcVersion < 706 = ["-user-package-conf"]
| otherwise = ["-user-package-db"]
ghcDbOpt (PackageDb pkgDb)
| ghcVersion < 706 = ["-no-user-package-conf", "-package-conf", pkgDb]
| otherwise = ["-no-user-package-db", "-package-db", pkgDb]