fix hotspot build failures with -D_FORTIFY_SOURCE=2 and -Wformat=1

[Christian Thalinger]

On Wed, 2008-12-03 at 13:38 +0100, Matthias Klose wrote:
> Christian Thalinger schrieb:
> > On Tue, 2008-12-02 at 18:12 +0100, Matthias Klose wrote:
> >> --- openjdk/hotspot/src/share/vm/prims/jvm.cpp~ 2008-11-20
> >> 09:41:05.000000000 +0100
> >> +++ openjdk/hotspot/src/share/vm/prims/jvm.cpp  2008-12-02
> >> 16:55:32.000000000 +0100
> >> @@ -2474,7 +2474,7 @@
> >>    if (Arguments::vfprintf_hook() != NULL) {
> >>      jio_fprintf(defaultStream::output_stream(), "%s", s);
> >>    } else {
> >> -    ::write(defaultStream::output_fd(), s, (int)strlen(s));
> >> +    ssize_t rv = ::write(defaultStream::output_fd(), s,
> >> (int)strlen(s));
> >>    }
> >>  }
> > 
> > David and Kelly already answered what I wanted to say, but as I still
> > have this compose window open since yesterday... :-)
> > 
> > I would also prefer the void cast here as it would be much clearer for
> > the unexperienced reader.
> 
> a void cast doesn't help. collected some suggestions, and the "best" seems to be
> 
>   ssize_t rv_neverused __attribute__((unused)) = ...
> 
> although this file cannot be built with -Wunused or -Wunused-variable anyway.

A void cast does not help?  What GCC version is that or even better,
what is the warning?

- Christian