hackport-0.5: cabal/Cabal/Distribution/Simple/Program/Db.hs
-----------------------------------------------------------------------------
-- |
-- Module : Distribution.Simple.Program.Db
-- Copyright : Isaac Jones 2006, Duncan Coutts 2007-2009
--
-- Maintainer : cabal-devel@haskell.org
-- Portability : portable
--
-- This provides a 'ProgramDb' type which holds configured and not-yet
-- configured programs. It is the parameter to lots of actions elsewhere in
-- Cabal that need to look up and run programs. If we had a Cabal monad,
-- the 'ProgramDb' would probably be a reader or state component of it.
--
-- One nice thing about using it is that any program that is
-- registered with Cabal will get some \"configure\" and \".cabal\"
-- helpers like --with-foo-args --foo-path= and extra-foo-args.
--
-- There's also a hook for adding programs in a Setup.lhs script. See
-- hookedPrograms in 'Distribution.Simple.UserHooks'. This gives a
-- hook user the ability to get the above flags and such so that they
-- don't have to write all the PATH logic inside Setup.lhs.
module Distribution.Simple.Program.Db (
-- * The collection of configured programs we can run
ProgramDb,
emptyProgramDb,
defaultProgramDb,
restoreProgramDb,
-- ** Query and manipulate the program db
addKnownProgram,
addKnownPrograms,
lookupKnownProgram,
knownPrograms,
getProgramSearchPath,
setProgramSearchPath,
modifyProgramSearchPath,
userSpecifyPath,
userSpecifyPaths,
userMaybeSpecifyPath,
userSpecifyArgs,
userSpecifyArgss,
userSpecifiedArgs,
lookupProgram,
updateProgram,
configuredPrograms,
-- ** Query and manipulate the program db
configureProgram,
configureAllKnownPrograms,
lookupProgramVersion,
reconfigurePrograms,
requireProgram,
requireProgramVersion,
) where
import Distribution.Simple.Program.Types
import Distribution.Simple.Program.Find
import Distribution.Simple.Program.Builtin
import Distribution.Simple.Utils
import Distribution.Version
import Distribution.Text
import Distribution.Verbosity
import Distribution.Compat.Binary
import Data.List
( foldl' )
import Data.Maybe
( catMaybes )
import Data.Tuple (swap)
import qualified Data.Map as Map
import Control.Monad
( join, foldM )
-- ------------------------------------------------------------
-- * Programs database
-- ------------------------------------------------------------
-- | The configuration is a collection of information about programs. It
-- contains information both about configured programs and also about programs
-- that we are yet to configure.
--
-- The idea is that we start from a collection of unconfigured programs and one
-- by one we try to configure them at which point we move them into the
-- configured collection. For unconfigured programs we record not just the
-- 'Program' but also any user-provided arguments and location for the program.
data ProgramDb = ProgramDb {
unconfiguredProgs :: UnconfiguredProgs,
progSearchPath :: ProgramSearchPath,
configuredProgs :: ConfiguredProgs
}
type UnconfiguredProgram = (Program, Maybe FilePath, [ProgArg])
type UnconfiguredProgs = Map.Map String UnconfiguredProgram
type ConfiguredProgs = Map.Map String ConfiguredProgram
emptyProgramDb :: ProgramDb
emptyProgramDb = ProgramDb Map.empty defaultProgramSearchPath Map.empty
defaultProgramDb :: ProgramDb
defaultProgramDb = restoreProgramDb builtinPrograms emptyProgramDb
-- internal helpers:
updateUnconfiguredProgs :: (UnconfiguredProgs -> UnconfiguredProgs)
-> ProgramDb -> ProgramDb
updateUnconfiguredProgs update conf =
conf { unconfiguredProgs = update (unconfiguredProgs conf) }
updateConfiguredProgs :: (ConfiguredProgs -> ConfiguredProgs)
-> ProgramDb -> ProgramDb
updateConfiguredProgs update conf =
conf { configuredProgs = update (configuredProgs conf) }
-- Read & Show instances are based on listToFM
-- | Note that this instance does not preserve the known 'Program's.
-- See 'restoreProgramDb' for details.
--
instance Show ProgramDb where
show = show . Map.toAscList . configuredProgs
-- | Note that this instance does not preserve the known 'Program's.
-- See 'restoreProgramDb' for details.
--
instance Read ProgramDb where
readsPrec p s =
[ (emptyProgramDb { configuredProgs = Map.fromList s' }, r)
| (s', r) <- readsPrec p s ]
-- | Note that this instance does not preserve the known 'Program's.
-- See 'restoreProgramDb' for details.
--
instance Binary ProgramDb where
put db = do
put (progSearchPath db)
put (configuredProgs db)
get = do
searchpath <- get
progs <- get
return $! emptyProgramDb {
progSearchPath = searchpath,
configuredProgs = progs
}
-- | The 'Read'\/'Show' and 'Binary' instances do not preserve all the
-- unconfigured 'Programs' because 'Program' is not in 'Read'\/'Show' because
-- it contains functions. So to fully restore a deserialised 'ProgramDb' use
-- this function to add back all the known 'Program's.
--
-- * It does not add the default programs, but you probably want them, use
-- 'builtinPrograms' in addition to any extra you might need.
--
restoreProgramDb :: [Program] -> ProgramDb -> ProgramDb
restoreProgramDb = addKnownPrograms
-- -------------------------------
-- Managing unconfigured programs
-- | Add a known program that we may configure later
--
addKnownProgram :: Program -> ProgramDb -> ProgramDb
addKnownProgram prog = updateUnconfiguredProgs $
Map.insertWith combine (programName prog) (prog, Nothing, [])
where combine _ (_, path, args) = (prog, path, args)
addKnownPrograms :: [Program] -> ProgramDb -> ProgramDb
addKnownPrograms progs conf = foldl' (flip addKnownProgram) conf progs
lookupKnownProgram :: String -> ProgramDb -> Maybe Program
lookupKnownProgram name =
fmap (\(p,_,_)->p) . Map.lookup name . unconfiguredProgs
knownPrograms :: ProgramDb -> [(Program, Maybe ConfiguredProgram)]
knownPrograms conf =
[ (p,p') | (p,_,_) <- Map.elems (unconfiguredProgs conf)
, let p' = Map.lookup (programName p) (configuredProgs conf) ]
-- | Get the current 'ProgramSearchPath' used by the 'ProgramDb'.
-- This is the default list of locations where programs are looked for when
-- configuring them. This can be overridden for specific programs (with
-- 'userSpecifyPath'), and specific known programs can modify or ignore this
-- search path in their own configuration code.
--
getProgramSearchPath :: ProgramDb -> ProgramSearchPath
getProgramSearchPath = progSearchPath
-- | Change the current 'ProgramSearchPath' used by the 'ProgramDb'.
-- This will affect programs that are configured from here on, so you
-- should usually set it before configuring any programs.
--
setProgramSearchPath :: ProgramSearchPath -> ProgramDb -> ProgramDb
setProgramSearchPath searchpath db = db { progSearchPath = searchpath }
-- | Modify the current 'ProgramSearchPath' used by the 'ProgramDb'.
-- This will affect programs that are configured from here on, so you
-- should usually modify it before configuring any programs.
--
modifyProgramSearchPath :: (ProgramSearchPath -> ProgramSearchPath)
-> ProgramDb
-> ProgramDb
modifyProgramSearchPath f db =
setProgramSearchPath (f $ getProgramSearchPath db) db
-- |User-specify this path. Basically override any path information
-- for this program in the configuration. If it's not a known
-- program ignore it.
--
userSpecifyPath :: String -- ^Program name
-> FilePath -- ^user-specified path to the program
-> ProgramDb -> ProgramDb
userSpecifyPath name path = updateUnconfiguredProgs $
flip Map.update name $ \(prog, _, args) -> Just (prog, Just path, args)
userMaybeSpecifyPath :: String -> Maybe FilePath
-> ProgramDb -> ProgramDb
userMaybeSpecifyPath _ Nothing conf = conf
userMaybeSpecifyPath name (Just path) conf = userSpecifyPath name path conf
-- |User-specify the arguments for this program. Basically override
-- any args information for this program in the configuration. If it's
-- not a known program, ignore it..
userSpecifyArgs :: String -- ^Program name
-> [ProgArg] -- ^user-specified args
-> ProgramDb
-> ProgramDb
userSpecifyArgs name args' =
updateUnconfiguredProgs
(flip Map.update name $
\(prog, path, args) -> Just (prog, path, args ++ args'))
. updateConfiguredProgs
(flip Map.update name $
\prog -> Just prog { programOverrideArgs = programOverrideArgs prog
++ args' })
-- | Like 'userSpecifyPath' but for a list of progs and their paths.
--
userSpecifyPaths :: [(String, FilePath)]
-> ProgramDb
-> ProgramDb
userSpecifyPaths paths conf =
foldl' (\conf' (prog, path) -> userSpecifyPath prog path conf') conf paths
-- | Like 'userSpecifyPath' but for a list of progs and their args.
--
userSpecifyArgss :: [(String, [ProgArg])]
-> ProgramDb
-> ProgramDb
userSpecifyArgss argss conf =
foldl' (\conf' (prog, args) -> userSpecifyArgs prog args conf') conf argss
-- | Get the path that has been previously specified for a program, if any.
--
userSpecifiedPath :: Program -> ProgramDb -> Maybe FilePath
userSpecifiedPath prog =
join . fmap (\(_,p,_)->p) . Map.lookup (programName prog) . unconfiguredProgs
-- | Get any extra args that have been previously specified for a program.
--
userSpecifiedArgs :: Program -> ProgramDb -> [ProgArg]
userSpecifiedArgs prog =
maybe [] (\(_,_,as)->as) . Map.lookup (programName prog) . unconfiguredProgs
-- -----------------------------
-- Managing configured programs
-- | Try to find a configured program
lookupProgram :: Program -> ProgramDb -> Maybe ConfiguredProgram
lookupProgram prog = Map.lookup (programName prog) . configuredProgs
-- | Update a configured program in the database.
updateProgram :: ConfiguredProgram -> ProgramDb
-> ProgramDb
updateProgram prog = updateConfiguredProgs $
Map.insert (programId prog) prog
-- | List all configured programs.
configuredPrograms :: ProgramDb -> [ConfiguredProgram]
configuredPrograms = Map.elems . configuredProgs
-- ---------------------------
-- Configuring known programs
-- | Try to configure a specific program. If the program is already included in
-- the collection of unconfigured programs then we use any user-supplied
-- location and arguments. If the program gets configured successfully it gets
-- added to the configured collection.
--
-- Note that it is not a failure if the program cannot be configured. It's only
-- a failure if the user supplied a location and the program could not be found
-- at that location.
--
-- The reason for it not being a failure at this stage is that we don't know up
-- front all the programs we will need, so we try to configure them all.
-- To verify that a program was actually successfully configured use
-- 'requireProgram'.
--
configureProgram :: Verbosity
-> Program
-> ProgramDb
-> IO ProgramDb
configureProgram verbosity prog conf = do
let name = programName prog
maybeLocation <- case userSpecifiedPath prog conf of
Nothing ->
programFindLocation prog verbosity (progSearchPath conf)
>>= return . fmap (swap . fmap FoundOnSystem . swap)
Just path -> do
absolute <- doesExecutableExist path
if absolute
then return (Just (UserSpecified path, []))
else findProgramOnSearchPath verbosity (progSearchPath conf) path
>>= maybe (die notFound)
(return . Just . swap . fmap UserSpecified . swap)
where notFound = "Cannot find the program '" ++ name
++ "'. User-specified path '"
++ path ++ "' does not refer to an executable and "
++ "the program is not on the system path."
case maybeLocation of
Nothing -> return conf
Just (location, triedLocations) -> do
version <- programFindVersion prog verbosity (locationPath location)
newPath <- programSearchPathAsPATHVar (progSearchPath conf)
let configuredProg = ConfiguredProgram {
programId = name,
programVersion = version,
programDefaultArgs = [],
programOverrideArgs = userSpecifiedArgs prog conf,
programOverrideEnv = [("PATH", Just newPath)],
programProperties = Map.empty,
programLocation = location,
programMonitorFiles = triedLocations
}
configuredProg' <- programPostConf prog verbosity configuredProg
return (updateConfiguredProgs (Map.insert name configuredProg') conf)
-- | Configure a bunch of programs using 'configureProgram'. Just a 'foldM'.
--
configurePrograms :: Verbosity
-> [Program]
-> ProgramDb
-> IO ProgramDb
configurePrograms verbosity progs conf =
foldM (flip (configureProgram verbosity)) conf progs
-- | Try to configure all the known programs that have not yet been configured.
--
configureAllKnownPrograms :: Verbosity
-> ProgramDb
-> IO ProgramDb
configureAllKnownPrograms verbosity conf =
configurePrograms verbosity
[ prog | (prog,_,_) <- Map.elems notYetConfigured ] conf
where
notYetConfigured = unconfiguredProgs conf
`Map.difference` configuredProgs conf
-- | reconfigure a bunch of programs given new user-specified args. It takes
-- the same inputs as 'userSpecifyPath' and 'userSpecifyArgs' and for all progs
-- with a new path it calls 'configureProgram'.
--
reconfigurePrograms :: Verbosity
-> [(String, FilePath)]
-> [(String, [ProgArg])]
-> ProgramDb
-> IO ProgramDb
reconfigurePrograms verbosity paths argss conf = do
configurePrograms verbosity progs
. userSpecifyPaths paths
. userSpecifyArgss argss
$ conf
where
progs = catMaybes [ lookupKnownProgram name conf | (name,_) <- paths ]
-- | Check that a program is configured and available to be run.
--
-- It raises an exception if the program could not be configured, otherwise
-- it returns the configured program.
--
requireProgram :: Verbosity -> Program -> ProgramDb
-> IO (ConfiguredProgram, ProgramDb)
requireProgram verbosity prog conf = do
-- If it's not already been configured, try to configure it now
conf' <- case lookupProgram prog conf of
Nothing -> configureProgram verbosity prog conf
Just _ -> return conf
case lookupProgram prog conf' of
Nothing -> die notFound
Just configuredProg -> return (configuredProg, conf')
where notFound = "The program '" ++ programName prog
++ "' is required but it could not be found."
-- | Check that a program is configured and available to be run.
--
-- Additionally check that the program version number is suitable and return
-- it. For example you could require 'AnyVersion' or @'orLaterVersion'
-- ('Version' [1,0] [])@
--
-- It returns the configured program, its version number and a possibly updated
-- 'ProgramDb'. If the program could not be configured or the version is
-- unsuitable, it returns an error value.
--
lookupProgramVersion
:: Verbosity -> Program -> VersionRange -> ProgramDb
-> IO (Either String (ConfiguredProgram, Version, ProgramDb))
lookupProgramVersion verbosity prog range programDb = do
-- If it's not already been configured, try to configure it now
programDb' <- case lookupProgram prog programDb of
Nothing -> configureProgram verbosity prog programDb
Just _ -> return programDb
case lookupProgram prog programDb' of
Nothing -> return $! Left notFound
Just configuredProg@ConfiguredProgram { programLocation = location } ->
case programVersion configuredProg of
Just version
| withinRange version range ->
return $! Right (configuredProg, version ,programDb')
| otherwise ->
return $! Left (badVersion version location)
Nothing ->
return $! Left (unknownVersion location)
where notFound = "The program '"
++ programName prog ++ "'" ++ versionRequirement
++ " is required but it could not be found."
badVersion v l = "The program '"
++ programName prog ++ "'" ++ versionRequirement
++ " is required but the version found at "
++ locationPath l ++ " is version " ++ display v
unknownVersion l = "The program '"
++ programName prog ++ "'" ++ versionRequirement
++ " is required but the version of "
++ locationPath l ++ " could not be determined."
versionRequirement
| isAnyVersion range = ""
| otherwise = " version " ++ display range
-- | Like 'lookupProgramVersion', but raises an exception in case of error
-- instead of returning 'Left errMsg'.
--
requireProgramVersion :: Verbosity -> Program -> VersionRange
-> ProgramDb
-> IO (ConfiguredProgram, Version, ProgramDb)
requireProgramVersion verbosity prog range programDb =
join $ either die return `fmap`
lookupProgramVersion verbosity prog range programDb