module Distribution.Compat.ResponseFile (expandResponse) where
import Distribution.Compat.Prelude
import Prelude ()
import System.FilePath
import System.IO (hPutStrLn, stderr)
import System.IO.Error
#if MIN_VERSION_base(4,12,0)
import GHC.ResponseFile (unescapeArgs)
#else
unescapeArgs :: String -> [String]
unescapeArgs = filter (not . null) . unescape
data Quoting = NoneQ | SngQ | DblQ
unescape :: String -> [String]
unescape args = reverse . map reverse $ go args NoneQ False [] []
where
go [] _q _bs a as = a:as
go (c:cs) q True a as = go cs q False (c:a) as
go (c:cs) q False a as
| '\\' == c = go cs q True a as
go (c:cs) SngQ False a as
| '\'' == c = go cs NoneQ False a as
| otherwise = go cs SngQ False (c:a) as
go (c:cs) DblQ False a as
| '"' == c = go cs NoneQ False a as
| otherwise = go cs DblQ False (c:a) as
go (c:cs) NoneQ False a as
| isSpace c = go cs NoneQ False [] (a:as)
| '\'' == c = go cs SngQ False a as
| '"' == c = go cs DblQ False a as
| otherwise = go cs NoneQ False (c:a) as
#endif
expandResponse :: [String] -> IO [String]
expandResponse = go recursionLimit "."
where
recursionLimit = 100
go :: Int -> FilePath -> [String] -> IO [String]
go n dir
| n >= 0 = fmap concat . traverse (expand n dir)
| otherwise = const $ hPutStrLn stderr "Error: response file recursion limit exceeded." >> exitFailure
expand :: Int -> FilePath -> String -> IO [String]
expand n dir arg@('@':f) = readRecursively n (dir </> f) `catchIOError` (const $ print "?" >> return [arg])
expand _n _dir x = return [x]
readRecursively :: Int -> FilePath -> IO [String]
readRecursively n f = go (n 1) (takeDirectory f) =<< unescapeArgs <$> readFile f