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SubjectRe: __user annotations
On Fri, Jun 06, 2003 at 05:43:58PM -0700, Linus Torvalds wrote:
>
> On Sat, 7 Jun 2003, Paul Mackerras wrote:
> > Linus Torvalds writes:
> >
> > > You can get check from
> > >
> > > bk://kernel.bkbits.net/torvalds/sparse
> >
> > Is that up to date? I cloned that repository and said "make" and got
> > heaps of compile errors. First there were a heap of warnings like
> > this:
>
> You need to have a modern compiler. The "heaps of errors" is what you get
> if you use a stone-age compiler that doesn't support anonymous structure
> and union members or other C99 features.
>
> Gcc has supported them since some pre-3.x version (which is pretty late,
> since they've been around in other compilers for much longer). They are a
> great way to make readable data structures that have internal structure
> _without_ having to have that structure show up unnecessarily in usage.

Actually, I believe they are an extension, which GCC honors. Unnamed
structures in standard C99 are actually declaring an unnamed type, not
an unnamed member. Try it:

struct {
int a;
union {
int b;
float c;
};
int d;
} foo;

int bar()
{
return foo.a + foo.d + foo.b;
}


With -std=c99, the reference to foo.b is an error; with -std=gnu99 or
-std=gnu89, it is accepted.


I don't know why they were getting rejected for Paul, though. Did you
have GNU set to -ansi mode?

--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
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