Yes, this slipped by my radar.
I've got my win8 build machine up now, so I can push something shortly.
On Mon, Aug 19, 2013 at 3:40 AM, Simon Peyton-Jones
Austin
Could you act on this thread please? Currently I think the Windows build is broken because of it.
I think Ian is right, namely that the way to get a particular bit-pattern with type 'Int' is to use fromIntegral. But it needs a comment to explain the idiom.
eg try compiling this with -O:
import Data.Int import Data.Word
foo :: Int32 foo = fromIntegral (0x80000000 :: Word32) :: Int32
You get
Foo.foo = GHC.Int.I32# (-2147483648)
-----Original Message----- From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of Ian Lynagh Sent: 05 August 2013 16:34 To: ghc-devs@haskell.org Subject: Re: Literal overflow test fails
On Sat, Aug 03, 2013 at 09:47:07PM +0000, Simon Peyton-Jones wrote:
libraries\Win32\Graphics\Win32\GDI\HDC.hs:145:14: Warning: Literal 2147483648 of type Int overflows
The offending code is:
setTextCharacterExtra dc extra = failIf (== 0x80000000) "SetTextCharacterExtra" $ c_SetTextCharacterExtra dc extra
- should we use minBound here?
The spec defines the failure value as 0x80000000, so it would be better to use that constant: http://msdn.microsoft.com/en-us/library/windows/desktop/dd145092%28v=vs.85%2...
I had a similar problem with a 0xdeadbeef constant in the compiler source. I changed it to be fromIntegral (0xdeadbeef :: Word32) instead. I'd suggest doing similarly for the 0x80000000.
- what should the new literal-overlflow code do for 0xblah constants?
In my opinion, it's doing the right thing.
Thanks Ian
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-- Regards, Austin - PGP: 4096R/0x91384671