Re: [PATCH v2 4/5] parse-options: introduce `OPTION_UNSIGNED`

>   - `OPTION_INTEGER` parses a signed integer.
> 
>   - `OPTION_MAGNITUDE` parses an unsigned integer, but it also
>     interprets suffixes like "k" or "g".
> 
> Notably missing is a middle ground that parses unsigned integers without
> interpreting suffixes. Introduce a new `OPTION_UNSIGNED` option type to
> plug this gap. This option type will be used in subsequent commits.
> 
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  parse-options.c               | 43 +++++++++++++++++++++++++++++++++++++++++++
>  parse-options.h               | 12 ++++++++++++
>  t/helper/test-parse-options.c |  4 +++-
>  t/t0040-parse-options.sh      | 18 +++++++++++++++++-
>  4 files changed, 75 insertions(+), 2 deletions(-)
> 
> diff --git a/parse-options.c b/parse-options.c
> index ae836c384c7..9670e46a679 100644
> --- a/parse-options.c
> +++ b/parse-options.c
> @@ -216,6 +216,49 @@ static enum parse_opt_result do_get_value(struct parse_opt_ctx_t *p,
>  			    optname(opt, flags));
>  		}
>  	}
> +	case OPTION_UNSIGNED:
> +	{
> +		uintmax_t upper_bound = UINTMAX_MAX >> (bitsizeof(uintmax_t) - CHAR_BIT * opt->precision);
> +		uintmax_t value;
> +
> +		if (unset) {
> +			value = 0;
> +		} else if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
> +			value = opt->defval;
> +		} else if (get_arg(p, opt, flags, &arg)) {
> +			return -1;
> +		} else if (!*arg) {
> +			return error(_("%s expects a numerical value"),
> +				     optname(opt, flags));
> +		} else {
> +			value = strtoumax(arg, (char **)&s, 10);
> +			if (*s)
> +				return error(_("%s expects a numerical value"),
> +					     optname(opt, flags));
> +		}
> +
> +		if (value > upper_bound)
> +			return error(_("value %"PRIuMAX" for %s exceeds %"PRIuMAX),
> +				     value, optname(opt, flags), upper_bound);
> +
> +		switch (opt->precision) {
> +		case 1:
> +			*(int8_t *)opt->value = value;

> +			return 0;
> +		case 2:
> +			*(int16_t *)opt->value = value;
> +			return 0;
> +		case 4:
> +			*(int32_t *)opt->value = value;
> +			return 0;
> +		case 8:
> +			*(int64_t *)opt->value = value;
> +			return 0;
> +		default:
> +			BUG("invalid precision for option %s",
> +			    optname(opt, flags));
> +		}
> +	}
>  	case OPTION_MAGNITUDE:
>  	{
>  		uintmax_t upper_bound = UINTMAX_MAX >> (bitsizeof(uintmax_t) - CHAR_BIT * opt->precision);