Jan Beulich writes ("Re: [PATCH v11 3/9] xen: introduce DECLARE_BOUNDS"):
> >No. This is not fine. Signed integer subtraction sometimes has UB.
...
> I've spent an hour trying to find the relevant parts of the spec, but I'm
> afraid I've once again failed at finding all necessary pieces.
The spe
>>> Ian Jackson 03/07/19 3:16 PM >>>
>Jan Beulich writes ("Re: [PATCH v11 3/9] xen: introduce DECLARE_BOUNDS"):
>> On 06.03.19 at 21:55, wrote:
>> > On Wed, 6 Mar 2019, Jan Beulich wrote:
>> > uintptr_t is the integer type corresponding to a pointer, so we should
>> > use uintptr_t first. ptrdiff
Jan Beulich writes ("Re: [PATCH v11 3/9] xen: introduce DECLARE_BOUNDS"):
> On 06.03.19 at 21:55, wrote:
> > On Wed, 6 Mar 2019, Jan Beulich wrote:
> > uintptr_t is the integer type corresponding to a pointer, so we should
> > use uintptr_t first. ptrdiff_t is the difference type so we should cast
>>> On 06.03.19 at 21:55, wrote:
> On Wed, 6 Mar 2019, Jan Beulich wrote:
>> > +static inline ptrdiff_t name ## _bytediff(const type s1[],
>> > \
>> > + const struct abstract_ ## name
>> > s2[])\
>> > +{
On Wed, 6 Mar 2019, Jan Beulich wrote:
> > +static inline ptrdiff_t name ## _diff(const type s1[],
> >\
> > + const struct abstract_ ## name s2[])
> >\
> > +{
>>> On 05.03.19 at 23:38, wrote:
> --- a/xen/include/xen/lib.h
> +++ b/xen/include/xen/lib.h
> @@ -173,4 +173,92 @@ void init_constructors(void);
> void *bsearch(const void *key, const void *base, size_t num, size_t size,
>int (*cmp)(const void *key, const void *elt));
>
> + /*
Introduce a MACRO to be used to declare array variables corresponding to
linker symbols, plus two static inline functions to be used for
comparing and subtracting pointers with the linker symbols.
Note that the start and end symbols are declared of different types to
help avoid errors and misusing
