{-# LANGUAGE Trustworthy #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE NoImplicitPrelude #-}

-----------------------------------------------------------------------------
-- |
-- Module      :  GHC.Internal.Windows
-- Copyright   :  (c) The University of Glasgow, 2009
-- License     :  see libraries/base/LICENSE
--
-- Maintainer  :  libraries@haskell.org
-- Stability   :  internal
-- Portability :  non-portable
--
-- Windows functionality used by several modules.
--
-- ToDo: this just duplicates part of System.Win32.Types, which isn't
-- available yet.  We should move some Win32 functionality down here,
-- maybe as part of the grand reorganisation of the base package...
--
-----------------------------------------------------------------------------

module GHC.Internal.Windows (
#if defined(javascript_HOST_ARCH)
                   ) where

#else
        -- * Types
        BOOL,
        LPBOOL,
        BYTE,
        DWORD,
        DDWORD,
        UINT,
        ULONG,
        ErrCode,
        HANDLE,
        LPWSTR,
        LPTSTR,
        LPCTSTR,
        LPVOID,
        LPDWORD,
        LPSTR,
        LPCSTR,
        LPCWSTR,
        WORD,
        UCHAR,
        NTSTATUS,

        -- * Constants
        iNFINITE,
        iNVALID_HANDLE_VALUE,

        -- * System errors
        throwGetLastError,
        failWith,
        getLastError,
        getErrorMessage,
        errCodeToIOError,

        -- ** Guards for system calls that might fail
        failIf,
        failIf_,
        failIfNull,
        failIfZero,
        failIfFalse_,
        failUnlessSuccess,
        failUnlessSuccessOr,

        -- ** Mapping system errors to errno
        -- $errno
        c_maperrno,
        c_maperrno_func,

        -- * Misc
        ddwordToDwords,
        dwordsToDdword,
        nullHANDLE,
    ) where

import GHC.Internal.Data.Bits (finiteBitSize, shiftL, shiftR, (.|.), (.&.))
import GHC.Internal.Unicode (isSpace)
import GHC.Internal.Data.OldList
import GHC.Internal.Data.Maybe
import GHC.Internal.Word
import GHC.Internal.Int
import GHC.Internal.Foreign.C.Error
import GHC.Internal.Foreign.C.String
import GHC.Internal.Foreign.C.Types
import GHC.Internal.Foreign.Ptr
import GHC.Internal.Base
import GHC.Internal.Enum (maxBound)
import GHC.Internal.IO
import GHC.Internal.Num
import GHC.Internal.Real (fromIntegral)
import GHC.Internal.System.IO.Error

import qualified GHC.Internal.Numeric

type BOOL     = Bool
type LPBOOL   = Ptr BOOL
type BYTE     = Word8
type DWORD    = Word32
type UINT     = Word32
type ULONG    = Word32
type ErrCode  = DWORD
type HANDLE   = Ptr ()
type LPWSTR   = Ptr CWchar
type LPCTSTR  = LPTSTR
type LPVOID   = Ptr ()
type LPDWORD  = Ptr DWORD
type LPSTR    = Ptr CChar
type LPCSTR   = LPSTR
type LPCWSTR  = LPWSTR
type WORD     = Word16
type UCHAR    = Word8
type NTSTATUS = Int32

nullHANDLE :: HANDLE
nullHANDLE :: HANDLE
nullHANDLE = HANDLE
forall a. Ptr a
nullPtr

-- Not really a basic type, but used in many places
type DDWORD        = Word64

-- | Be careful with this.  LPTSTR can mean either WCHAR* or CHAR*, depending
-- on whether the UNICODE macro is defined in the corresponding C code.
-- Consider using LPWSTR instead.
type LPTSTR = LPWSTR

iNFINITE :: DWORD
iNFINITE :: Word32
iNFINITE = Word32
0xFFFFFFFF -- urgh

iNVALID_HANDLE_VALUE :: HANDLE
iNVALID_HANDLE_VALUE :: HANDLE
iNVALID_HANDLE_VALUE = WordPtr -> HANDLE
forall a. WordPtr -> Ptr a
wordPtrToPtr (-WordPtr
1)

-- | Get the last system error, and throw it as an 'IOError' exception.
throwGetLastError :: String -> IO a
throwGetLastError :: forall a. String -> IO a
throwGetLastError String
where_from =
    IO Word32
getLastError IO Word32 -> (Word32 -> IO a) -> IO a
forall a b. IO a -> (a -> IO b) -> IO b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= String -> Word32 -> IO a
forall a. String -> Word32 -> IO a
failWith String
where_from

-- | Convert a Windows error code to an exception, then throw it.
failWith :: String -> ErrCode -> IO a
failWith :: forall a. String -> Word32 -> IO a
failWith String
fn_name Word32
err_code =
    String -> Word32 -> IO IOException
errCodeToIOError String
fn_name Word32
err_code IO IOException -> (IOException -> IO a) -> IO a
forall a b. IO a -> (a -> IO b) -> IO b
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= IOException -> IO a
forall e a. (HasCallStack, Exception e) => e -> IO a
throwIO

-- | Convert a Windows error code to an exception.
errCodeToIOError :: String -> ErrCode -> IO IOError
errCodeToIOError :: String -> Word32 -> IO IOException
errCodeToIOError String
fn_name Word32
err_code = do
    msg <- Word32 -> IO String
getErrorMessage Word32
err_code

    -- turn GetLastError() into errno, which errnoToIOError knows
    -- how to convert to an IOException we can throw.
    -- XXX we should really do this directly.
    let errno = Word32 -> Errno
c_maperrno_func Word32
err_code

    let msg' = (Char -> Bool) -> String -> String
forall a. (a -> Bool) -> [a] -> [a]
dropWhileEnd Char -> Bool
isSpace String
msg -- drop trailing \n
        ioerror = String -> Errno -> Maybe Handle -> Maybe String -> IOException
errnoToIOError String
fn_name Errno
errno Maybe Handle
forall a. Maybe a
Nothing Maybe String
forall a. Maybe a
Nothing
                    IOException -> String -> IOException
`ioeSetErrorString` String
msg'
    return ioerror

-- | Get a string describing a Windows error code.  This uses the
-- @FormatMessage@ system call.
getErrorMessage :: ErrCode -> IO String
getErrorMessage :: Word32 -> IO String
getErrorMessage Word32
err_code =
    IO String -> IO String
forall a. IO a -> IO a
mask_ (IO String -> IO String) -> IO String -> IO String
forall a b. (a -> b) -> a -> b
$ do
        c_msg <- Word32 -> IO (Ptr CWchar)
c_getErrorMessage Word32
err_code
        if c_msg == nullPtr
          then return $ "Error 0x" ++ GHC.Internal.Numeric.showHex err_code ""
          else do msg <- peekCWString c_msg
                  -- We ignore failure of freeing c_msg, given we're already failing
                  _ <- localFree c_msg
                  return msg

failIf :: (a -> Bool) -> String -> IO a -> IO a
failIf :: forall a. (a -> Bool) -> String -> IO a -> IO a
failIf a -> Bool
p String
wh IO a
act = do
    v <- IO a
act
    if p v then throwGetLastError wh else return v

failIf_ :: (a -> Bool) -> String -> IO a -> IO ()
failIf_ :: forall a. (a -> Bool) -> String -> IO a -> IO ()
failIf_ a -> Bool
p String
wh IO a
act = do
    v <- IO a
act
    if p v then throwGetLastError wh else return ()

failIfNull :: String -> IO (Ptr a) -> IO (Ptr a)
failIfNull :: forall a. String -> IO (Ptr a) -> IO (Ptr a)
failIfNull = (Ptr a -> Bool) -> String -> IO (Ptr a) -> IO (Ptr a)
forall a. (a -> Bool) -> String -> IO a -> IO a
failIf (Ptr a -> Ptr a -> Bool
forall a. Eq a => a -> a -> Bool
== Ptr a
forall a. Ptr a
nullPtr)

failIfZero :: (Eq a, Num a) => String -> IO a -> IO a
failIfZero :: forall a. (Eq a, Num a) => String -> IO a -> IO a
failIfZero = (a -> Bool) -> String -> IO a -> IO a
forall a. (a -> Bool) -> String -> IO a -> IO a
failIf (a -> a -> Bool
forall a. Eq a => a -> a -> Bool
== a
0)

failIfFalse_ :: String -> IO Bool -> IO ()
failIfFalse_ :: String -> IO Bool -> IO ()
failIfFalse_ = (Bool -> Bool) -> String -> IO Bool -> IO ()
forall a. (a -> Bool) -> String -> IO a -> IO ()
failIf_ Bool -> Bool
not

failUnlessSuccess :: String -> IO ErrCode -> IO ()
failUnlessSuccess :: String -> IO Word32 -> IO ()
failUnlessSuccess String
fn_name IO Word32
act = do
    r <- IO Word32
act
    if r == 0 then return () else failWith fn_name r

failUnlessSuccessOr :: ErrCode -> String -> IO ErrCode -> IO Bool
failUnlessSuccessOr :: Word32 -> String -> IO Word32 -> IO Bool
failUnlessSuccessOr Word32
val String
fn_name IO Word32
act = do
    r <- IO Word32
act
    if r == 0 then return False
        else if r == val then return True
        else failWith fn_name r

-- $errno
--
-- On Windows, @errno@ is defined by msvcrt.dll for compatibility with other
-- systems, and is distinct from the system error as returned
-- by @GetLastError@.

-- | Map the last system error to an errno value, and assign it to @errno@.
foreign import ccall unsafe "maperrno"             -- in Win32Utils.c
   c_maperrno :: IO ()

-- | Pure function variant of 'c_maperrno' that does not call @GetLastError@
-- or modify @errno@.
foreign import ccall unsafe "maperrno_func"        -- in Win32Utils.c
   c_maperrno_func :: ErrCode -> Errno

foreign import ccall unsafe "base_getErrorMessage" -- in Win32Utils.c
    c_getErrorMessage :: DWORD -> IO LPWSTR

foreign import ccall unsafe "windows.h LocalFree"
    localFree :: Ptr a -> IO (Ptr a)

-- | Get the last system error produced in the current thread.
foreign import ccall unsafe "windows.h GetLastError"
    getLastError :: IO ErrCode

----------------------------------------------------------------
-- Misc helpers
----------------------------------------------------------------

ddwordToDwords :: DDWORD -> (DWORD,DWORD)
ddwordToDwords :: Word64 -> (Word32, Word32)
ddwordToDwords Word64
n =
        (Word64 -> Word32
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word64
n Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftR` Word32 -> Int
forall b. FiniteBits b => b -> Int
finiteBitSize (Word32
forall a. HasCallStack => a
undefined :: DWORD))
        ,Word64 -> Word32
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word64
n Word64 -> Word64 -> Word64
forall a. Bits a => a -> a -> a
.&. Word32 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word32
forall a. Bounded a => a
maxBound :: DWORD)))

dwordsToDdword:: (DWORD,DWORD) -> DDWORD
dwordsToDdword :: (Word32, Word32) -> Word64
dwordsToDdword (Word32
hi,Word32
low) = (Word32 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word32
low) Word64 -> Word64 -> Word64
forall a. Bits a => a -> a -> a
.|. (Word32 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word32
hi Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftL` Word32 -> Int
forall b. FiniteBits b => b -> Int
finiteBitSize Word32
hi)

#endif