I appear to have tracked down the bug for ffi021: the new
code generator doesn't appear to clear the tag bit for the
pointer to heap before:
// outOfLine should follow:
(_sR1::I32,) = foreign "ccall"
_sQR::I32((I32[_sRi::I32 + 7], `signed'),
(I32[_sRi::I32 + 11], PtrHint),
(I32[_sRi::I32 + 15],))[_unsafe_call_];
// emitReturn: Sequel: Assign
;
(gdb) disas
Dump of assembler code for function sRi_info:
=> 0x0804aa6c <+0>: mov %esi,%eax
0x0804aa6e <+2>: lea 0x0(%ebp),%ecx
0x0804aa71 <+5>: cmp 0x54(%ebx),%ecx
0x0804aa74 <+8>: jb 0x804aab3 <sRi_info+71>
0x0804aa76 <+10>: add $0x4,%ebp
0x0804aa79 <+13>: add $0x8,%edi
0x0804aa7c <+16>: cmp 0x5c(%ebx),%edi
0x0804aa7f <+19>: ja 0x804aaa4 <sRi_info+56>
0x0804aa81 <+21>: pushl 0xf(%eax)
0x0804aa84 <+24>: pushl 0xb(%eax)
0x0804aa87 <+27>: pushl 0x7(%eax)
0x0804aa8a <+30>: call *%eax
The pushes to the stack properly untag eax, but then we just
call the tagged pointer, which seems pretty wrong to me. Here is
the old C--:
(_sR1::I32,) = foreign "ccall"
I32[R1 + 3]((_cSc::I32, `signed'), (_cSe::I32, PtrHint),
(_cSg::I32,))[_unsafe_call_];
Unfortunately, I can't figure out where this +3 is supposed to
be happening, so I don't have a patch. Some guidance here would
be appreciated.
Cheers,
Edward
_______________________________________________
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
