Re: [Qemu-devel] [PATCH RFC 08/13] range: add Range structure

[Peter Maydell]

On 13 May 2013 21:01, Michael S. Tsirkin <address@hidden> wrote:
> Sometimes we need to pass ranges around, add a
> handy structure for this purpose.
>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> ---
>  include/qemu/range.h | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/include/qemu/range.h b/include/qemu/range.h
> index 3502372..4bcd346 100644
> --- a/include/qemu/range.h
> +++ b/include/qemu/range.h
> @@ -1,6 +1,28 @@
>  #ifndef QEMU_RANGE_H
>  #define QEMU_RANGE_H
>
> +#include <inttypes.h>
> +
> +/*
> + * Operations on 64 address ranges.

missing "bit" ?

> + * Notes:
> + *   - ranges must not wrap around 0, but can include the last byte ~0x0LL.
> + *   - this can not represent a full 0 to ~0x0LL range.
> + */
> +
> +/* A structure representing a range of addresses. */
> +struct Range {
> +    uint64_t begin; /* First byte of the range, or 0 if empty. */
> +    uint64_t end;   /* 1 + the last byte. 0 if range empty or ends at 
> ~0x0LL. */
> +};
> +typedef struct Range Range;
> +
> +/* verify that range is not empty and does not overlap */

Doesn't overlap what? Why isn't an empty range valid?
The struct definition above says it's OK.

> +static inline bool range_valid(struct Range *range)
> +{
> +    return range->begin + 1 <= range->end;
> +}

I note that memory.c defines its own concept of an AddrRange.

thanks
-- PMM