Re: [Qemu-devel] [PATCH v1 4/7] range: add some more functions

[David Hildenbrand]

On 11/10/2018 11:08, Dr. David Alan Gilbert wrote:
> * David Hildenbrand (address@hidden) wrote:
>> Add some more functions that will be used in memory-device context.
>>
>> range_init(): Init using lower bound and size
>> range_valid(): Check if there would be an overflow when initializin
>> 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
>> range_starts_before_range(): Check if one range starts before another
>> range_ends_after_range(): Check if one range ends after another
>>
>> Signed-off-by: David Hildenbrand <address@hidden>
>> ---
>>  include/qemu/range.h | 80 ++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 80 insertions(+)
>>
>> diff --git a/include/qemu/range.h b/include/qemu/range.h
>> index 7e75f4e655..18e8acf22f 100644
>> --- a/include/qemu/range.h
>> +++ b/include/qemu/range.h
>> @@ -112,6 +112,86 @@ static inline uint64_t range_upb(Range *range)
>>      return range->upb;
>>  }
>>  
>> +/*
>> + * Initialize @range to span the interval address@hidden,@lob + @size - 1].
>> + * @size may be 0.
>> + */
>> +static inline void range_init(Range *range, uint64_t lob, uint64_t size)
>> +{
>> +    range->lob = lob;
>> +    range->upb = lob + size - 1;
>> +    range_invariant(range);
>> +}
>> +
>> +/*
>> + * Check if the interval address@hidden,@lob + @size - 1] would be valid or 
>> not
>> + * (result in an overflow).
>> + */
>> +static inline bool range_valid(uint64_t lob, uint64_t size)
>> +{
>> +    return lob + size >= lob;
>> +}
> 
> That name confused me, I'd expected that to have taken a range and check
> it for something (like a non-asserting version of the invariant).

Then we have to remove all the variant asserts from the initializer
functions (well, because then it is no longer an invariant then). Other
ideas?

-- 

Thanks,

David / dhildenb