Re: [RFA] Handle cygwin wchar_t specifics

[Corinna Vinschen <vinschen@redhat.com>]

Hi Tom,

On Apr 15 12:15, Tom Tromey wrote:
> >>>>> "Pierre" == Pierre Muller <pierre.muller@ics-cnrs.unistra.fr> writes:
> 
> Pierre> because of this, GDB uses "UCS-4LE" 
> Pierre> for the macro INTERMEDIATE_ENCODING on Cygwin 
> Pierre> (while "wchar_t" it uses for mingw32, which works well).
> 
> Ok, I see the problem.  I thought this:
> 
>     /* If __STDC_ISO_10646__ is defined, then the host wchar_t is UCS-4.
> 
> But this is not true!  For some values of __STDC_ISO_10646__, a 2 byte
> wide character type suffices.  In particular, Cygwin's value of 200305
> means that it corresponds to Unicode 4.0.0:
> 
>     http://www.unicode.org/versions/components-4.0.0.html
> 
> I think this might be a Cygwin bug, but it is pretty hard to wade
> through the ISO / Unicode differences and other assorted standardese to
> see.  (The reason I think it might be a bug is that Unicode 4.0.0
> defines some characters > 0xFFFF.)

I see there's another solution in the works, but just to let you know
that Bruno Haible and I discussed the definition of __STDC_ISO_10646__
on the Cygwin list back in January.  We didn't come to a conclusion
since we both interpret the standards differently, but this gives
you some insight why __STDC_ISO_10646__ is defined on Cygwin, see
http://cygwin.com/ml/cygwin/2011-01/msg00410.html, line 70ff.


Corinna

-- 
Corinna Vinschen
Cygwin Project Co-Leader
Red Hat