ghcup-hs/lib/GHCup/Utils/File/Posix/Foreign.hsc
Julian Ospald 48aee1e76c
[WIP] Prototype of recording installed files
This also installs makefile based build system via DESTDIR
into a temporary directory and then merges it into the filesystem.
2022-05-13 00:46:47 +02:00

78 lines
2.3 KiB
Haskell

{-# LANGUAGE PatternSynonyms #-}
module GHCup.Utils.File.Posix.Foreign where
import Data.Bits
import Data.List (foldl')
import Foreign.C.Types
#include <limits.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
newtype DirType = DirType Int deriving (Eq, Show)
data Flags = Flags Int | UnsupportedFlag String deriving (Eq, Show)
unFlags :: Flags -> Int
unFlags (Flags i) = i
unFlags (UnsupportedFlag name) = error (name ++ " is not supported on this platform")
-- |Returns @True@ if posix-paths was compiled with support for the provided
-- flag. (As of this writing, the only flag for which this check may be
-- necessary is 'oCloexec'; all other flags will always yield @True@.)
isSupported :: Flags -> Bool
isSupported (Flags _) = True
isSupported _ = False
-- |@O_CLOEXEC@ is not supported on every POSIX platform. Use
-- @'isSupported' oCloexec@ to determine if support for @O_CLOEXEC@ was
-- compiled into your version of posix-paths. (If not, using @oCloexec@ will
-- throw an exception.)
oCloexec :: Flags
#ifdef O_CLOEXEC
oCloexec = Flags #{const O_CLOEXEC}
#else
{-# WARNING oCloexec
"This version of posix-paths was compiled without @O_CLOEXEC@ support." #-}
oCloexec = UnsupportedFlag "O_CLOEXEC"
#endif
-- If these enum declarations occur earlier in the file, haddock
-- gets royally confused about the above doc comments.
-- Probably http://trac.haskell.org/haddock/ticket/138
#{enum DirType, DirType, DT_BLK, DT_CHR, DT_DIR, DT_FIFO, DT_LNK, DT_REG, DT_SOCK, DT_UNKNOWN}
#{enum Flags, Flags, O_APPEND, O_ASYNC, O_CREAT, O_DIRECTORY, O_EXCL, O_NOCTTY, O_NOFOLLOW, O_NONBLOCK, O_RDONLY, O_WRONLY, O_RDWR, O_SYNC, O_TRUNC}
pathMax :: Int
pathMax = #{const PATH_MAX}
unionFlags :: [Flags] -> CInt
unionFlags = fromIntegral . foldl' ((. unFlags) . (.|.)) 0
pattern DtBlk :: DirType
pattern DtBlk <- dtBlk
pattern DtChr :: DirType
pattern DtChr <- dtChr
pattern DtDir :: DirType
pattern DtDir <- dtdir
pattern DtFifo :: DirType
pattern DtFifo <- dtFifo
pattern DtLnk :: DirType
pattern DtLnk <- dtLnk
pattern DtReg :: DirType
pattern DtReg <- dtReg
pattern DtSock :: DirType
pattern DtSock <- dtSock
pattern DtUnknown :: DirType
pattern DtUnknown <- dtUnknown
{-# COMPLETE DtBlk, DtChr, DtDir, DtFifo, DtLnk, DtReg, DtSock, DtUnknown #-}