Re: CURRENT: CLANG 3.3 and -stad=c++11 and -stdlib=libc++: isnan()/isninf() oddity

On Fri, 12 Jul 2013 12:13:58 -0500
Scot Hetzel <swhetzel_at_gmail.com> wrote:

> On Fri, Jul 12, 2013 at 11:16 AM, Scot Hetzel <swhetzel_at_gmail.com>
> wrote:
> > On Thu, Jul 11, 2013 at 9:33 AM, David Chisnall
> > <theraven_at_freebsd.org> wrote:
> >> On 11 Jul 2013, at 13:11, Bruce Evans <brde_at_optusnet.com.au> wrote:
> >>
> >>> The error message for the __builtin_isnan() version is slightly
> >>> better up to where it says more.
> >>>
> >>> The less-unportable macro can do more classification and detect
> >>> problems at compile time using __typeof().
> >>
> >> The attached patch fixes the related test cases in the libc++ test
> >> suite.  Please review.
> >>
> >
> >  #define        fpclassify(x) \
> > -    ((sizeof (x) == sizeof (float)) ? __fpclassifyf(x) \
> > -    : (sizeof (x) == sizeof (double)) ? __fpclassifyd(x) \
> > -    : __fpclassifyl(x))
> > +        __fp_type_select(x, __fpclassifyf, __fpclassifyd,
> > __fpclassifyd)
> >
> > The last __fpclassifyd should be __fpclassifyl.
> >
> I see it has already been fixed.
> 
> 

Obviously not really fixed, but even worse:

if I use in C code (C99, using clang 3.3 on FreeBSD 10.0-CURRENT/amd64
revision 253287) isnan(x) where x is a "const double", I receive now
the following error (which doesn't appear on previous versions):

[...]
Making all in scaling
/bin/sh ../../libtool  --tag=CC   --mode=compile cc -DHAVE_CONFIG_H -I.
-I../..  -I. -I../  -I/usr/local/include  -O0 -march=native -g -pipe
-DHAVE_INLINE -g -O2 -MT libscaling_la-scalingTransientCroft.lo -MD -MP
-MF .deps/libscaling_la-scalingTransientCroft.Tpo -c -o
libscaling_la-scalingTransientCroft.lo `test -f
'scalingTransientCroft.c' || echo './'`scalingTransientCroft.c libtool:
compile:  cc -DHAVE_CONFIG_H -I. -I../.. -I. -I../ -I/usr/local/include
-O0 -march=native -g -pipe -DHAVE_INLINE -g -O2 -MT
libscaling_la-scalingTransientCroft.lo -MD -MP
-MF .deps/libscaling_la-scalingTransientCroft.Tpo -c
scalingTransientCroft.c -o libscaling_la-scalingTransientCroft.o
scalingTransientCroft.c:48:12: error: controlling expression type
'const double' not compatible with any generic association type if
(isnan(Dsg) || isnan(Dsc)) ^~~ /usr/include/math.h:109:19: note:
expanded from macro 'isnan' __fp_type_select(x, __inline_isnanf,
__inline_isnan, __inline_isnanl) ^ /usr/include/math.h:86:49: note:
expanded from macro '__fp_type_select' #define __fp_type_select(x, f,
d, ld) _Generic((x), 
[...]

The variables in question (Dsg and Dsc) are of type "const double".