Re: Portability problem with SCM_DEBUG_TYPING_STRICTNESS=1

[Dirk Herrmann]

On 8 Jun 2001, Matthias Koeppe wrote:

> > In this case, I think we should wait until scm_t_bits is made into an
> > unsigned type.  Then, instead of writing 0xFFFUL we should probably write
> > (scm_t_bits) 0xFFF.  Currently, as long as scm_t_bits is signed, this
> > wouldn't solve your problem.
> 
> Yes it does solve the problem because the integer overflow happens at
> shift time, not at assignment time.  0xFFF << 20 has the 31st bit set,
> so it does not fit into a signed 32-bit integer. 0xFFFU << 20,
> however, is a nice unsigned 32-bit integer; assigning it to a
> scm_bits_t location does not cause an error or warning, whether
> scm_bits_t is unsigned or not.

Sorry for being unclear:  Yes, your patch solves the problem (i. e. you
don't get warnings any more).  But, I am not sure it is The Right
Thing.  IMO, the cast to scm_t_bits would be The Right Thing, but this
will not help to get rid of the warnings yet.

Best regards,
Dirk Herrmann