[Haskell-cafe] Re: HDirect, [unique], troubles again!

[Sigbjorn Finne]

Two things not quite working out here:
  
 - HDirect treated 'unique' as 'ref' for function pointers;
    that's easier to work with if 'unique' was the inferred/default
    kind, but clearly not what you want if you explicitly supplied
    a 'unique' attribute.
 - The by-ref marshallers for function types have types with shapes
    slightly different from other by-ref marshallers. Hence, extra
    care is required when emitting marshallers for types that contain
    them.

Both of these issues have now been fixed in the CVS repository.

--sigbjorn

----- Original Message ----- 
From: "Vincenzo aka Nick Name" <vincenzo_mlRE.MOVE at yahoo.it>
To: <haskell-cafe at haskell.org>
Cc: "Sigbjorn Finne" <sof at galois.com>
Sent: Wednesday, May 05, 2004 13:51
Subject: HDirect, [unique], troubles again!


> In my quest for a fuse binding for Haskell, which I really need at the 
> moment, I have the following definition working:
> 
> module HSFuse {
>   interface stat{};
>   
>   typedef int getattrT([string] char *,stat);
> 
>   typedef struct fuseOps {
>     [ref] getattrT * getattr;
>   } fuseOps;
> 
>   void fuse_main(int argc,[in,string,size_is(argc)]char** argv,[ref] 
> fuseOps * op);
> };
> 
> but when I substitute "ref" with "unique", because some operations can 
> be null, I get the errors below. The problem is that in the generated 
> hs file there is
> 
> data FuseOps = FuseOps {getattr :: GetattrT}
> 
> which completely ignores my type declaration! Did I do something wrong?
> 
> Commands invoked and errors follow, thanks for attention:
> 
> ihc -fhs-to-c -fuse-ints-everywhere -c HSFuse.idl
> ghc  -package hdirect -fglasgow-exts HSFuse.hs -c
> 
> HSFuse.hs:136:
>     Couldn't match
>         `GHC.Base.String -> Stat -> GHC.IOBase.IO GHC.Base.Int'
>         against
>         `GHC.Ptr.Ptr
>              (GHC.Base.String -> Stat -> GHC.IOBase.IO GHC.Base.Int)'
>         Expected type: GHC.Ptr.Ptr
>                            (GHC.Ptr.Ptr
>                                 (GHC.Base.String -> Stat -> 
> GHC.IOBase.IO GHC.Base.Int))
>                        -> GHC.Ptr.Ptr
>                               (GHC.Base.String -> Stat -> GHC.IOBase.IO 
> GHC.Base.Int)
>                           -> GHC.IOBase.IO ()
>         Inferred type: GHC.Ptr.Ptr
>                            (GHC.Ptr.Ptr
>                                 (GHC.Base.String -> Stat -> 
> GHC.IOBase.IO GHC.Base.Int))
>                        -> (GHC.Base.String -> Stat -> GHC.IOBase.IO 
> GHC.Base.Int)
>                           -> GHC.IOBase.IO ()
>     In the second argument of `HDirect.writeunique', namely
>         `writeGetattrT'
>     In the definition of `writeFuseOps':
>         writeFuseOps ptr (FuseOps getattr)
>                        = let
>                            pf0 = ptr
>                            pf1 = HDirect.addNCastPtr pf0 0
>                          in
>                            HDirect.writeunique (HDirect.allocBytes 
> (GHC.Real.fromIntegral sizeofGetattrT))
>                                                writeGetattrT
>                                                pf1
>                                                getattr