Re: [RFA] Move cpplib to the toplevel

[Andrew Pinski <pinskia at physics dot uc dot edu>]

On May 29, 2004, at 08:34, Paolo Bonzini wrote:

> > Note that sizeof (_Bool) is defined by C99 as at
> > least the sizeof (char) so it is wrong to check for
> > to see that the sizeof (_Bool) == 1, in fact there
> > is one major target/host which defines sizeof(_Bool)==4
> > and this is powerpc-apple-darwin.
>
> Though, IIRC the C++ ABI mandates that sizeof (bool) == 1,
> so sizeof (_Bool) > 1 is guaranteed to cause troubles in
> C/C++ interoperability: in this case, it seems better to
> me if you say that there is no bool.

Yes the IA64 C++ ABI says that sizeof(bool) should equal to
1.  But Apple did not want to break backward compatibility
with code written before the ABI was written so they kept
the sizeof(bool) and sizeof(_Bool) to equal to 4 instead
of 1 like the ABI.  So powerpc-apple-darwin does not follow
the IA64 C++ ABI to the wire but instead is modified version
of it with only the sizeof(bool) being different.

This has been discussed before when the bootstrap of the
tree-ssa was ICEing because it would remove the cast from
int to _Bool.

Thanks,
Andrew Pinski