Subject: Re: [PATCH 2/6] parse-options: add precision handling for OPTION_SET_INT

From: Patrick Steinhardt <[email-masked]>
Date: Tue, 1 Jul 2025 12:55:19 +0200

On Sun, Jun 29, 2025 at 01:50:39PM +0200, René Scharfe wrote:
> diff --git a/parse-options.c b/parse-options.c
> index da07a000a3..bbb68603cc 100644
> --- a/parse-options.c
> +++ b/parse-options.c
> @@ -85,6 +85,36 @@ static intmax_t get_int_value(const struct option *opt)
>  	}
>  }
>  
> +static enum parse_opt_result set_int_value(const struct option *opt,
> +					   enum opt_parsed flags,
> +					   intmax_t value)
> +{
> +	switch (opt->precision) {
> +	case sizeof(int8_t):
> +		*(int8_t *)opt->value = value;
> +		return 0;
> +	case sizeof(int16_t):
> +		*(int16_t *)opt->value = value;
> +		return 0;
> +	case sizeof(int32_t):
> +		*(int32_t *)opt->value = value;
> +		return 0;
> +	case sizeof(int64_t):
> +		*(int64_t *)opt->value = value;
> +		return 0;
> +	default:
> +		BUG("invalid precision for option %s", optname(opt, flags));
> +	}
> +}

The function only ever dies or returns successfully, so can't we make it
return nothing instead? On the other hand it does make a couple of
callsites a bit nicer to read.

> +static int signed_int_fits(intmax_t value, size_t size)
> +{
> +	size_t bits = size * CHAR_BIT;
> +	intmax_t upper_bound = INTMAX_MAX >> (bitsizeof(intmax_t) - bits);
> +	intmax_t lower_bound = -upper_bound - 1;
> +	return lower_bound <= value && value <= upper_bound;
> +}
> +

Should we s/size/precision/ so that it's clear what kind of size this
exactly is?

Patrick