On Sun, Jun 24, 2007 at 08:18:52PM +0200, Segher Boessenkool wrote:
> >#define _IOC_TYPECHECK(t) \
> > ((sizeof(t) == sizeof(t[1]) && \
> > sizeof(t) < (1 << _IOC_SIZEBITS)) ? \
> > sizeof(t) : __invalid_size_argument_for_IOC)
> >poisoning _IOW() et.al., so those who do something like
> >
> >static const char *v4l1_ioctls[] = {
> > [_IOC_NR(VIDIOCGCAP)] = "VIDIOCGCAP",
> >
> >run into trouble.
>
> >The only reason that doesn't break gcc to hell and back is
> >that gcc has unfixed bugs in that area.
>
> If I understand correctly what bugs you are talking about,
> most (all?) of those were solved in the dark ages already
> (i.e., the 3.x series).
Alas, no. gcc is amazingly (and inconsistently) sloppy about the
things it accepts as integer constant expressions.
> >It certainly is not a valid C
>
> Why not? Nothing in the C standard says all your externs
> have to be defined in some other translation unit you link
> with AFAIK.
It's not about externs. It's about things like
unsigned n;
int a[] = {[n - n + n - n] = 1};
And yes, gcc does eat that. With -pedantic -std=c99, at that.
However,
unsigned n;
int a[] = {[n + n - n - n] = 1};
gets you error: nonconstant array index in initializer
And that's 4.1, not 3.x...
-
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
