On 10/03/2012 11:04 AM, Søren Sandmann wrote: > From: Søren Sandmann Pedersen <s...@redhat.com> > > Apparently GCC 4.5 still warns about "value computed not used" even > with __attribute__((unused)). Fix this by only doing the compile time > check on gcc > 4.5. > > Signed-off-by: Soren Sandmann <s...@redhat.com> > --- > > I need this patch to get qemu to compile with GCC 4.5, but I'm not > sure if 4.5 is the right compiler version to check against. > > osdep.h | 5 +++-- > 1 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/osdep.h b/osdep.h > index cb213e0..df89552 100644 > --- a/osdep.h > +++ b/osdep.h > @@ -41,8 +41,9 @@ typedef signed int int_fast16_t; > #endif > > /* Convert from a base type to a parent type, with compile time checking. */ > -#ifdef __GNUC__ > -#define DO_UPCAST(type, field, dev) ( __extension__ ( { \ > +#if defined (__GNUC__) && \ > + (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ > 5)) > +#define DO_UPCAST(type, field, dev) ( __extension__ ( { \ > char __attribute__((unused)) offset_must_be_zero[ \ > -offsetof(type, field)]; \ > container_of(dev, type, field);}))
Try moving the attribute to the end of the declaration, i.e. just before the semi-colon. r~