Re: [Qemu-devel] [qemu-s390x] [PATCH v5 04/12] s390-ccw: update libc

[Thomas Huth]

On 05.02.2018 21:57, Collin L. Walling wrote:
> Moved:
>   memcmp from bootmap.h to libc.h (renamed from _memcmp)
>   strlen from sclp.c to libc.h (renamed from _strlen)
> 
> Added C standard functions:
>   isdigit
> 
> Added non C-standard function:
>   itostr
>   atoui
> 
> Signed-off-by: Collin L. Walling <address@hidden>
> Acked-by: Christian Borntraeger <address@hidden>
> Reviewed-by: Janosch Frank <address@hidden>
> ---
[...]
> +/**
> + * itostr:
> + * @num: an integer (base 10) to be converted.
> + * @str: a pointer to a string to store the conversion.
> + * @len: the length of the passed string.
> + *
> + * Given an integer @num, convert it to a string. The string @str must be
> + * allocated beforehand. The resulting string will be null terminated and
> + * returned. This function only handles numbers between 0 and UINT64_MAX
> + * inclusive.
> + *
> + * Returns: the string @str of the converted integer @num; NULL if @str
> + * is NULL or if there is not enough space allocated.
> + */
> +char *itostr(uint64_t num, char *str, size_t len)

Nitpicking: You renamed atoi to atoui, so maybe this should now rather
be uitostr or uitoa now?

> +{
> +    size_t num_idx = 0;
> +    uint64_t tmp = num;
> +
> +    IPL_assert(num >= 0, "itostr: cannot convert negative values");

(already mentioned by patchew)

> +    IPL_assert(str != NULL, "itostr: no space allocated to store string");
> +
> +    /* Get index to ones place */
> +    while ((tmp /= 10) != 0) {
> +        num_idx++;
> +    }
> +
> +    /* Check if we have enough space for num and null */
> +    IPL_assert(len >= num_idx + 1, "itostr: array too small for conversion");

Should that rather be "len > num_idx + 1" instead?

> +    str[num_idx + 1] = '\0';
> +
> +    /* Convert int to string */
> +    while (num_idx >= 0) {
> +        str[num_idx] = num % 10 + '0';
> +        num /= 10;
> +        num_idx--;
> +    }
> +
> +    return str;
> +}

 Thomas