From: Jonathan Nieder <jrnieder@gmail.com>
Date: Tue, 27 Jul 2010 21:37:50 GMT
Subject: Re: [PATCH 1/4] Allow detached form (e.g. "-S foo" instead of "-Sfoo") for diff options
Message-ID: <20100727213750.GB11768@burratino>
In-Reply-To: <1280265719-30968-2-git-send-email-Matthieu.Moy@imag.fr>

Matthieu Moy wrote:

> +++ b/diff.c
> @@ -2990,9 +2990,23 @@ static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *va
[...]
> +#define IF_SHORT_OPT(optname)			\
> +	((!strcmp(arg, "-" #optname)		\
> +	  && (argv[1] || (die("Option `" #optname "' requires a value"), 1),	\
> +	      optarg   = argv[1],	       		\
> +	      argcount = 2,			\
> +	      1)) ||				\
> +	 (!prefixcmp(arg, "-" #optname)		\
> +	  && (optarg = arg + strlen("-" #optname),	\
> +	      argcount = 1,			\
> +	       1)))
> +

Why not something like this?

	static inline int short_opt(char opt, const char *arg,
					const char *argv, const char **optarg)
	{
		if (arg[0] != '-' || arg[1] != opt)
			return 0;
		if (arg[2] != '\0') {
			*optarg = arg + strlen("-c");
			return 1;
		}
		if (!argv[1])
			die("Option '%c' requires a value", opt);
		*optarg = argv[1];
		return 2;
	}

and then:

	if ((argcount = short_opt('S', arg, argv, &optarg))) {
		...

> +++ b/diff.h
> @@ -214,6 +214,21 @@ extern void diff_unmerge(struct diff_options *,
>  #define DIFF_SETUP_USE_CACHE		2
>  #define DIFF_SETUP_USE_SIZE_CACHE	4
>  
> +/*
> + * Poor man's alternative to parse-option, only meant to be used in
> + * handle_revision_opt and  diff_opt_parse.
> + */
> +#define IF_LONG_OPT(optname)					\
> +	((!strcmp(arg, "--" #optname)				\
> +	  && (argv[1] || (die("Option `" #optname "' requires a value"), 1), \
> +	      optarg   = argv[1],	       			\
> +	      argcount = 2,					\
> +	      1)) ||						\
> +	 (!prefixcmp(arg, "--" #optname "=")			\
> +	  && (optarg = arg + strlen("--" #optname "="),		\
> +	      argcount = 1,					\
> +	      1)))


 static int long_opt(const char *opt, const char *arg,
				const char **argv, const char **optarg)
 {
	if (arg[0] != '-' || arg[1] != '-')
		return 0;
	if (prefixcmp(arg, opt))
		return 0;
	arg += strlen("--") + strlen(opt);
	if (*arg == '=') {
		*optarg = arg + 1;
		return 1;
	}
	if (*arg != '\0')
		return 0;
	if (!argv[1])
		die("Option '--%s' requires a value", opt);
	*optarg = argv[1];
	return 2;
 }

Jonathan