xref: /dpdk/lib/eal/windows/getopt.c (revision a06fb0fae6ab6a79fa3e8288dbb0c5166be843c2)

/* SPDX-License-Identifier: ISC AND BSD-2-Clause
 * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */
/*
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Dieter Baron and Thomas Klausner.
 */

#include <getopt.h>

#ifdef NEED_USUAL_GETOPT

#include <string.h>
#include <stdlib.h>

char    *optarg;		/* argument associated with option */
int	opterr = 1;		/* if error message should be printed */
int	optind = 1;		/* index into parent argv vector */
int	optopt = '?';		/* character checked for validity */

static void pass(const char *a) {(void) a; }
#define warnx(a, ...) pass(a)

#define PRINT_ERROR	((opterr) && (*options != ':'))

#define FLAG_PERMUTE	0x01	/* permute non-options to the end of argv */
#define FLAG_ALLARGS	0x02	/* treat non-options as args to option "-1" */
#define FLAG_LONGONLY	0x04	/* operate as getopt_long_only */

/* return values */
#define	BADCH		((int)'?')
#define	BADARG		((*options == ':') ? (int)':' : (int)'?')
#define	INORDER		1

static char EMSG[] = "";

static char *place = EMSG; /* option letter processing */

/* XXX: set optreset to 1 rather than these two */
static int nonopt_start = -1; /* first non option argument (for permute) */
static int nonopt_end = -1;   /* first option after non options (for permute) */

/* Error messages */
static const char recargchar[] = "option requires an argument -- %c";
static const char recargstring[] = "option requires an argument -- %s";
static const char ambig[] = "ambiguous option -- %.*s";
static const char noarg[] = "option doesn't take an argument -- %.*s";
static const char illoptchar[] = "unknown option -- %c";
static const char illoptstring[] = "unknown option -- %s";

/*
 * Compute the greatest common divisor of a and b.
 */
static int
gcd(int a, int b)
{
	int c;

	c = a % b;
	while (c != 0) {
		a = b;
		b = c;
		c = a % b;
	}

	return (b);
}

/*
 * Exchange the block from nonopt_start to nonopt_end with the block
 * from nonopt_end to opt_end (keeping the same order of arguments
 * in each block).
 */
static void
permute_args(int panonopt_start, int panonopt_end, int opt_end,
	char * const *nargv)
{
	int cstart, cyclelen, i, j, ncycle, nnonopts, nopts, pos;
	char *swap;

	/*
	 * compute lengths of blocks and number and size of cycles
	 */
	nnonopts = panonopt_end - panonopt_start;
	nopts = opt_end - panonopt_end;
	ncycle = gcd(nnonopts, nopts);
	cyclelen = (opt_end - panonopt_start) / ncycle;

	for (i = 0; i < ncycle; i++) {
		cstart = panonopt_end+i;
		pos = cstart;
		for (j = 0; j < cyclelen; j++) {
			if (pos >= panonopt_end)
				pos -= nnonopts;
			else
				pos += nopts;

			swap = nargv[pos];
			/* LINTED const cast */
			((char **)(uintptr_t)nargv)[pos] = nargv[cstart];
			/* LINTED const cast */
			((char **)(uintptr_t)nargv)[cstart] = swap;
		}
	}
}

/*
 * parse_long_options --
 *	Parse long options in argc/argv argument vector.
 * Returns -1 if short_too is set and the option does not match long_options.
 */
static int
parse_long_options(char * const *nargv, const char *options,
	const struct option *long_options, int *idx, int short_too)
{
	const char *current_argv;
	char *has_equal;
	size_t current_argv_len;
	int i, match;

	current_argv = place;
	match = -1;

	optind++;

	has_equal = strchr(current_argv, '=');
	if (has_equal != NULL) {
		/* argument found (--option=arg) */
		current_argv_len = has_equal - current_argv;
		has_equal++;
	} else
		current_argv_len = strlen(current_argv);

	for (i = 0; long_options[i].name; i++) {
		/* find matching long option */
		if (strncmp(current_argv, long_options[i].name,
		    current_argv_len))
			continue;

		if (strlen(long_options[i].name) == current_argv_len) {
			/* exact match */
			match = i;
			break;
		}
		/*
		 * If this is a known short option, don't allow
		 * a partial match of a single character.
		 */
		if (short_too && current_argv_len == 1)
			continue;

		if (match == -1)	/* partial match */
			match = i;
		else {
			/* ambiguous abbreviation */
			if (PRINT_ERROR)
				warnx(ambig, (int)current_argv_len,
				     current_argv);
			optopt = 0;
			return BADCH;
		}
	}
	if (match != -1) {		/* option found */
		if (long_options[match].has_arg == no_argument
		    && has_equal) {
			if (PRINT_ERROR)
				warnx(noarg, (int)current_argv_len,
				     current_argv);
			/*
			 * XXX: GNU sets optopt to val regardless of flag
			 */
			if (long_options[match].flag == NULL)
				optopt = long_options[match].val;
			else
				optopt = 0;
			return BADARG;
		}
		if (long_options[match].has_arg == required_argument ||
		    long_options[match].has_arg == optional_argument) {
			if (has_equal)
				optarg = has_equal;
			else if (long_options[match].has_arg ==
			    required_argument) {
				/*
				 * optional argument doesn't use next nargv
				 */
				optarg = nargv[optind++];
			}
		}
		if ((long_options[match].has_arg == required_argument)
		    && (optarg == NULL)) {
			/*
			 * Missing argument; leading ':' indicates no error
			 * should be generated.
			 */
			if (PRINT_ERROR)
				warnx(recargstring,
				    current_argv);
			/*
			 * XXX: GNU sets optopt to val regardless of flag
			 */
			if (long_options[match].flag == NULL)
				optopt = long_options[match].val;
			else
				optopt = 0;
			--optind;
			return BADARG;
		}
	} else {			/* unknown option */
		if (short_too) {
			--optind;
			return (-1);
		}
		if (PRINT_ERROR)
			warnx(illoptstring, current_argv);
		optopt = 0;
		return BADCH;
	}
	if (idx)
		*idx = match;
	if (long_options[match].flag) {
		*long_options[match].flag = long_options[match].val;
		return 0;
	} else
		return (long_options[match].val);
}

/*
 * getopt_internal --
 *	Parse argc/argv argument vector.  Called by user level routines.
 */
static int
getopt_internal(int nargc, char *const nargv[], const char *options,
	const struct option *long_options, int *idx, int flags)
{
	char *oli;				/* option letter list index */
	int optchar, short_too;
	static int posixly_correct = -1;
	size_t len;
	int optreset = 0;

	if (options == NULL)
		return (-1);

	/*
	 * Disable GNU extensions if POSIXLY_CORRECT is set or options
	 * string begins with a '+'.
	 */
	if (posixly_correct == -1) {
		errno_t err = _wgetenv_s(&len, NULL, 0, L"POSIXLY_CORRECT");
		posixly_correct = (err == 0) && (len > 0);
	}
	if (!posixly_correct || *options == '+')
		flags &= ~FLAG_PERMUTE;
	else if (*options == '-')
		flags |= FLAG_ALLARGS;
	if (*options == '+' || *options == '-')
		options++;
	/*
	 * reset if requested
	 */
	if (optind == 0)
		optind = optreset = 1;

	optarg = NULL;
	if (optreset)
		nonopt_start = nonopt_end = -1;
start:
	if (optreset || !*place) {		/* update scanning pointer */
		optreset = 0;
		if (optind >= nargc) {          /* end of argument vector */
			place = EMSG;
			if (nonopt_end != -1) {
				/* do permutation, if we have to */
				permute_args(nonopt_start, nonopt_end,
				    optind, nargv);
				optind -= nonopt_end - nonopt_start;
			} else if (nonopt_start != -1) {
				/*
				 * If we skipped non-options, set optind
				 * to the first of them.
				 */
				optind = nonopt_start;
			}
			nonopt_start = nonopt_end = -1;
			return (-1);
		}
		place = nargv[optind];
		if (*place != '-' ||
		    (place[1] == '\0' && strchr(options, '-') == NULL)) {
			place = EMSG;		/* found non-option */
			if (flags & FLAG_ALLARGS) {
				/*
				 * GNU extension:
				 * return non-option as argument to option 1
				 */
				optarg = nargv[optind++];
				return INORDER;
			}
			if (!(flags & FLAG_PERMUTE)) {
				/*
				 * If no permutation wanted, stop parsing
				 * at first non-option.
				 */
				return (-1);
			}
			/* do permutation */
			if (nonopt_start == -1)
				nonopt_start = optind;
			else if (nonopt_end != -1) {
				permute_args(nonopt_start, nonopt_end,
				    optind, nargv);
				nonopt_start = optind -
				    (nonopt_end - nonopt_start);
				nonopt_end = -1;
			}
			optind++;
			/* process next argument */
			goto start;
		}
		if (nonopt_start != -1 && nonopt_end == -1)
			nonopt_end = optind;

		/*
		 * If we have "-" do nothing, if "--" we are done.
		 */
		if (place[1] != '\0' && *++place == '-' && place[1] == '\0') {
			optind++;
			place = EMSG;
			/*
			 * We found an option (--), so if we skipped
			 * non-options, we have to permute.
			 */
			if (nonopt_end != -1) {
				permute_args(nonopt_start, nonopt_end,
				    optind, nargv);
				optind -= nonopt_end - nonopt_start;
			}
			nonopt_start = nonopt_end = -1;
			return (-1);
		}
	}

	/*
	 * Check long options if:
	 *  1) we were passed some
	 *  2) the arg is not just "-"
	 *  3) either the arg starts with -- we are getopt_long_only()
	 */
	if (long_options != NULL && place != nargv[optind] &&
	    (*place == '-' || (flags & FLAG_LONGONLY))) {
		short_too = 0;
		if (*place == '-')
			place++;		/* --foo long option */
		else if (*place != ':' && strchr(options, *place) != NULL)
			short_too = 1;		/* could be short option too */

		optchar = parse_long_options(nargv, options, long_options,
		    idx, short_too);
		if (optchar != -1) {
			place = EMSG;
			return optchar;
		}
	}

	optchar = (int)*place++;
	oli = strchr(options, optchar);
	if (optchar == (int)':' ||
	    (optchar == (int)'-' && *place != '\0') ||
	    oli == NULL) {
		/*
		 * If the user specified "-" and  '-' isn't listed in
		 * options, return -1 (non-option) as per POSIX.
		 * Otherwise, it is an unknown option character (or ':').
		 */
		if (optchar == (int)'-' && *place == '\0')
			return (-1);
		if (!*place)
			++optind;
		if (PRINT_ERROR)
			warnx(illoptchar, optchar);
		optopt = optchar;
		return BADCH;
	}
	if (long_options != NULL && optchar == 'W' && oli[1] == ';') {
		/* -W long-option */
		if (*place)
			;
		else if (++optind >= nargc) {	/* no arg */
			place = EMSG;
			if (PRINT_ERROR)
				warnx(recargchar, optchar);
			optopt = optchar;
			return BADARG;
		}				/* white space */
		place = nargv[optind];
		optchar = parse_long_options(nargv, options, long_options,
		    idx, 0);
		place = EMSG;
		return optchar;
	}
	if (*++oli != ':') {			/* doesn't take argument */
		if (!*place)
			++optind;
	} else {				/* takes (optional) argument */
		optarg = NULL;
		if (*place)			/* no white space */
			optarg = place;
		else if (oli[1] != ':') {	/* arg not optional */
			if (++optind >= nargc) {	/* no arg */
				place = EMSG;
				if (PRINT_ERROR)
					warnx(recargchar, optchar);
				optopt = optchar;
				return BADARG;
			}
			optarg = nargv[optind];
		}
		place = EMSG;
		++optind;
	}
	/* dump back option letter */
	return optchar;
}

/*
 * getopt --
 *	Parse argc/argv argument vector.
 */
int
getopt(int nargc, char *const nargv[], const char *options)
{
	return getopt_internal(nargc, nargv, options, NULL, NULL,
			       FLAG_PERMUTE);
}

/*
 * getopt_long --
 *	Parse argc/argv argument vector.
 */
int
getopt_long(int nargc, char *const nargv[], const char *options,
	const struct option *long_options, int *idx)
{

	return (getopt_internal(nargc, nargv, options, long_options, idx,
	    FLAG_PERMUTE));
}

/*
 * getopt_long_only --
 *	Parse argc/argv argument vector.
 */
int
getopt_long_only(int nargc, char *const nargv[], const char *options,
	const struct option *long_options, int *idx)
{

	return (getopt_internal(nargc, nargv, options, long_options, idx,
	    FLAG_PERMUTE|FLAG_LONGONLY));
}

#endif /* NEED_USUAL_GETOPT */