Re: [Qemu-devel] [PATCH v3 4/7] range: add some more functions

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 1 Nov 2018 11:29:51 +0100
David Hildenbrand <david@redhat.com> wrote:

> On 01.11.18 11:00, Igor Mammedov wrote:
> > On Tue, 23 Oct 2018 17:23:03 +0200
> > David Hildenbrand <david@redhat.com> wrote:
> >   
> >> Add some more functions that will be used in memory-device context.
> >>
> >> range_init(): Init using lower bound and size, check for validity
> >> range_init_nofail(): Init using lower bound and size, validity asserted
> >> range_size(): Extract the size of a range
> >> range_overlaps_range(): Check for overlaps of two ranges
> >> range_contains_range(): Check if one range is contained in the other
> >>
> >> Signed-off-by: David Hildenbrand <david@redhat.com>
> >> ---
> >>  include/qemu/range.h | 62 ++++++++++++++++++++++++++++++++++++++++++++
> >>  1 file changed, 62 insertions(+)
> >>
> >> diff --git a/include/qemu/range.h b/include/qemu/range.h
> >> index 7e75f4e655..ba606c6bc0 100644
> >> --- a/include/qemu/range.h
> >> +++ b/include/qemu/range.h
> >> @@ -112,6 +112,68 @@ static inline uint64_t range_upb(Range *range)
> >>      return range->upb;
> >>  }
> >>  
> >> +/*
> >> + * Initialize @range to span the interval [@lob,@lob + @size - 1].
> >> + * @size may be 0. If the range would overflow, returns -ERANGE, otherwise
> >> + * 0.
> >> + */
> >> +static inline int QEMU_WARN_UNUSED_RESULT range_init(Range *range, uint64_t lob,
> >> +                                                     uint64_t size)
> >> +{
> >> +    if (lob + size < lob) {
> >> +        return -ERANGE;
> >> +    }
> >> +    range->lob = lob;
> >> +    range->upb = lob + size - 1;
> >> +    range_invariant(range);
> >> +    return 0;
> >> +}
> >> +
> >> +/*
> >> + * Initialize @range to span the interval [@lob,@lob + @size - 1].
> >> + * @size may be 0. Range must not overflow.
> >> + */
> >> +static inline void range_init_nofail(Range *range, uint64_t lob, uint64_t size)
> >> +{
> >> +    range->lob = lob;
> >> +    range->upb = lob + size - 1;
> >> +    range_invariant(range);
> >> +}
> >> +
> >> +/*
> >> + * Get the size of @range.
> >> + */
> >> +static inline uint64_t range_size(const Range *range)
> >> +{
> >> +    return range->upb - range->lob + 1;
> >> +}
> >> +
> >> +/*
> >> + * Check if @range1 overlaps with @range2. If one of the ranges is empty,
> >> + * the result is always "false".
> >> + */
> >> +static inline bool range_overlaps_range(const Range *range1,
> >> +                                        const Range *range2)
> >> +{
> >> +    if (range_is_empty(range1) || range_is_empty(range2)) {  
> > compilation fails with:
> >  "error: passing argument 1 of ‘range_is_empty’ discards ‘const’ qualifier from pointer target type [-Werror]"
> > 
> > the same for range_invariant,
> > following should fix issues:  
> 
> I guess you missed patch #3.
Yep, I was applying it randomly. I'd squash 3 and 4 but considering 3
it already queued  there is no point in doing so.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>