GHC FFI Return Type Bug

[Ashley Yakeley]

Has anyone else come across this? I've only tried this with Word8 but I 
suspect this is a problem with all return types smaller than four bytes.

I've entered this as GHC bug #448104.
<http://sourceforge.net/tracker/index.php?func=detail&aid=448104&group_id=8
032&atid=108032>

Here's the C code:

extern "C"
	{
	unsigned char foo();
	}

inline void use(const char* s)
	{
	}

unsigned char foo()
	{
	const char* s = "";
	use(s);
	return 0;
	}

...and the Haskell looks something like this:

 foreign import foo :: IO Word8

do {
 w8 <- foo;
 putStrLn (show (w8 :: Word8));
}

...and the result is this:
1074803712

Kind of an unusual Word8 value! But note that the low byte of this value 
is zero.

My setup:

$ ghc -v
Glasgow Haskell Compiler, Version 5.00, for Haskell 98, compiled by GHC 
version 5.00
Using package config file: /usr/lib/ghc-5.00/package.conf
Hsc static flags: -static -fignore-interface-pragmas 
-fomit-interface-pragmas -fdo-lambda-eta-expansion -flet-no-escape

$ uname -a
Linux server 2.2.19pre17 #1 Tue Mar 13 22:37:59 EST 2001 i686 unknown


-- 
Ashley Yakeley, Seattle WA