win32.py: add argtypes and restype This is a feature of ctypes. Without these, pypy complains with RuntimeWarning: C function without declared arguments called RuntimeWarning: C function without declared return type called As a side effect of specifying restypes, the return value of e.g. CreateFileA is now implicitly converted to an instance of _HANDLE, so we also need to change the definition _INVALID_HANDLE_VALUE = -1 to _INVALID_HANDLE_VALUE = _HANDLE(-1).value Otherwise, tests for equality to _INVALID_HANDLE_VALUE in code like def _getfileinfo(name): fh = _kernel32.CreateFileA(name, 0, _FILE_SHARE_READ | _FILE_SHARE_WRITE | _FILE_SHARE_DELETE, None, _OPEN_EXISTING, 0, None) if fh == _INVALID_HANDLE_VALUE: _raiseoserror(name) would now fail to detect an invalid handle, which in turn would lead to exceptions raised with wrong errno values, like e.g. >>> nlinks('missing.txt') Traceback (most recent call last): ... OSError: [Errno 9] missing.txt: The handle is invalid. instead of the correct (as per this patch and before it) >>> nlinks('missing.txt') Traceback (most recent call last): ... OSError: [Errno 2] missing.txt: The system cannot find the file specified.