Respect signedness of literals (#78)

* Use maxBound instead of (-1) to define iNVALID_HANDLE_VALUE

The former results in an out-of-bounds literal warning (introduced in GHC 8.2).

* Menu: Use maxBound instead of (-1) to discern error

The value being compared against is unsigned so (-1) is technically out
of range.

* Window: Define cW_USE_DEFAULT as Int, not Word

Since its value is signed.

* Using NegativeLiterals

* use negative number to fit bit pattern.

* use negative number to fit bit pattern

* Weird convoluted way to get a value with the top bit set..

* Add clarifying comment.

* Mark for release.

Graphics/Win32/Menu.hsc

@@ -79,7 +79,7 @@ type MenuName = LPCTSTR
 
 checkMenuItem :: HMENU -> MenuItem -> MenuFlag -> IO Bool
 checkMenuItem menu item check = do
-  rv <- failIf (== -1) "CheckMenuItem" $ c_CheckMenuItem menu item check
+  rv <- failIf (== maxBound) "CheckMenuItem" $ c_CheckMenuItem menu item check
   return (rv == mF_CHECKED)
 foreign import WINDOWS_CCONV unsafe "windows.h CheckMenuItem"
   c_CheckMenuItem :: HMENU -> UINT -> UINT -> IO DWORD
@@ -230,13 +230,13 @@ foreign import WINDOWS_CCONV unsafe "windows.h GetMenu"
 
 getMenuDefaultItem :: HMENU -> Bool -> GMDIFlag -> IO MenuItem
 getMenuDefaultItem menu bypos flags =
-  failIf (== -1) "GetMenuDefaultItem" $ c_GetMenuDefaultItem menu bypos flags
+  failIf (== maxBound) "GetMenuDefaultItem" $ c_GetMenuDefaultItem menu bypos flags
 foreign import WINDOWS_CCONV unsafe "windows.h GetMenuDefaultItem"
   c_GetMenuDefaultItem :: HMENU -> Bool -> UINT -> IO UINT
 
 getMenuState :: HMENU -> MenuItem -> MenuFlag -> IO MenuState
 getMenuState menu item flags =
-  failIf (== -1) "GetMenuState" $ c_GetMenuState menu item flags
+  failIf (== maxBound) "GetMenuState" $ c_GetMenuState menu item flags
 foreign import WINDOWS_CCONV unsafe "windows.h GetMenuState"
   c_GetMenuState :: HMENU -> UINT -> UINT -> IO MenuState
 
@@ -254,15 +254,15 @@ foreign import WINDOWS_CCONV unsafe "windows.h SetMenu"
 
 getMenuItemCount :: HMENU -> IO Int
 getMenuItemCount menu =
-  failIf (== -1) "GetMenuItemCount" $ c_GetMenuItemCount menu
+  failIf (== maxBound) "GetMenuItemCount" $ c_GetMenuItemCount menu
 foreign import WINDOWS_CCONV unsafe "windows.h GetMenuItemCount"
   c_GetMenuItemCount :: HMENU -> IO Int
 
 type MenuID = UINT
 
 getMenuItemID :: HMENU -> MenuItem -> IO MenuID
 getMenuItemID menu item =
-  failIf (== -1) "GetMenuItemID" $ c_GetMenuItemID menu item
+  failIf (== maxBound) "GetMenuItemID" $ c_GetMenuItemID menu item
 foreign import WINDOWS_CCONV unsafe "windows.h GetMenuItemID"
   c_GetMenuItemID :: HMENU -> UINT -> IO MenuID
 

Graphics/Win32/Window.hsc

@@ -1,4 +1,5 @@
 {-# LANGUAGE CApiFFI #-}
+{-# LANGUAGE NegativeLiterals #-}
 #if __GLASGOW_HASKELL__ >= 701
 {-# LANGUAGE Trustworthy #-}
 #endif
@@ -20,7 +21,7 @@ module Graphics.Win32.Window where
 
 import Control.Monad (liftM)
 import Data.Maybe (fromMaybe)
-import Data.Word (Word32)
+import Data.Int (Int32)
 import Foreign.ForeignPtr (withForeignPtr)
 import Foreign.Marshal.Alloc (allocaBytes)
 import Foreign.Ptr (FunPtr, Ptr, castFunPtrToPtr, castPtr, nullPtr)
@@ -185,7 +186,10 @@ type WindowStyleEx   = DWORD
 
 cW_USEDEFAULT :: Pos
 -- See Note [Overflow checking and fromIntegral] in Graphics/Win32/GDI/HDC.hs
-cW_USEDEFAULT = fromIntegral (#{const CW_USEDEFAULT} :: Word32)
+-- Weird way to essentially get a value with the top bit set. But GHC 7.8.4 was
+-- rejecting all other sane attempts.
+cW_USEDEFAULT = let val = negate (#{const CW_USEDEFAULT}) :: Integer
+                in fromIntegral (fromIntegral val :: Int32) :: Pos
 
 type Pos = Int
 

System/Win32/Types.hsc

@@ -219,7 +219,7 @@ nullFinalHANDLE :: ForeignPtr a
 nullFinalHANDLE = unsafePerformIO (newForeignPtr_ nullPtr)
 
 iNVALID_HANDLE_VALUE :: HANDLE
-iNVALID_HANDLE_VALUE = castUINTPtrToPtr (-1)
+iNVALID_HANDLE_VALUE = castUINTPtrToPtr maxBound
 
 foreign import ccall "_open_osfhandle"
   _open_osfhandle :: CIntPtr -> CInt -> IO CInt

Win32.cabal

@@ -1,5 +1,5 @@
 name:		Win32
-version:	2.5.1.0
+version:	2.5.2.0
 license:	BSD3
 license-file:	LICENSE
 author:		Alastair Reid, shelarcy

changelog.md

@@ -1,7 +1,8 @@
 # Changelog for [`Win32` package](http://hackage.haskell.org/package/Win32)
 
-## Unreleased GIT version
+## 2.5.2.0 *March 2017*
 
+* Fix constant underflows with (-1) and unsigned numbers.
 * Add `commandLineToArgv`
 
 ## 2.5.1.0 *Feb 2017*