/* $NetBSD: getopt.c,v 1.1 2009/03/22 22:33:13 joerg Exp $*/
/*  Modified by David Anderson to work with GNU/Linux and freebsd.
    Added {} for clarity.
    Switched to standard dwarfdump formatting.
    Treatment of : modified so that :: gets dwoptarg NULL
    if space follows the letter
    (the dwoptarg is set to null).
    renamed to make it clear this is a private version.
    Oct 17 2017: Created dwgetopt_long(). See dwgetopt.h
*/
/*
* Copyright (c) 1987, 1993, 1994
* The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
*    copyright notice, this list of conditions and the following
*    disclaimer in the documentation and/or other materials
*    provided with the distribution.
* 3. Neither the name of the University nor the names of its
*    contributors may be used to endorse or promote products
*    derived from this software without specific prior written
*    permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT
* SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*  This does not presently handle the option string
    leading + or leading - features. Such are not used
    by by libdwarfdump.  Nor does it understand the
    GNU Env var POSIXLY_CORRECT .
    It does know of the leading ":" in the option string.
    See BADCH below.
    */

#include <config.h>

#include <stddef.h> /* NULL size_t */
#include <stdio.h>  /* fprintf() */
#include <string.h> /* strlen() strchr() strcmp() strncmp() */

#include "dd_getopt.h"

#define STRIP_OFF_CONSTNESS(a)  ((void *)(size_t)(const void *)(a))

int dwopterr = 1,    /* if error message should be printed */
    dwoptind = 1,    /* index into parent argv vector */
    dwoptopt,        /* character checked for validity */
    dwoptreset;      /* reset getopt */
char *dwoptarg;      /* argument associated with option */

#define BADCH   (int)'?'
#define BADARG  (int)':'
#define EMSG    ""

#define TRUE 1
#define FALSE 0

#if 0 /* FOR DEBUGGING ONLY */
/*  Use for testing dwgetopt only.
    Not a standard function. */
void
dwgetoptresetfortestingonly(void)
{
    dwopterr   = 1;
    dwoptind   = 1;
    dwoptopt   = 0;
    dwoptreset = 0;
    dwoptarg   = 0;
}
#endif /* FOR DEBUGGING ONLY */

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

/*  Post Condition:
    if return FALSE then *argerr is set false. */
static int
dwoptnamematches(
    const struct dwoption *dwlopt,
    const char *iplace,
    const char **argloc,
    int *argerr)
{

    const char *eq = 0;
    unsigned namelen = 0;
    unsigned arglen = 0;
    int d = 0;

    for (eq = iplace; *eq; ++eq) {
        if (*eq != '=') {
            continue;
        }
        /* Found  =, arg should follow */
        namelen = (eq - iplace);
        if (namelen != (unsigned)strlen(dwlopt->name)) {
            return FALSE;
        }
        eq++;
        arglen = strlen(eq);
        break;
    }
    if (namelen) {
        d = strncmp(iplace,dwlopt->name,namelen);
        if (d) {
            return FALSE;
        }
        if (dwlopt->has_arg == 0) {
            *argerr = TRUE;
            return TRUE;
        }
        if (arglen) {
            /*  Discarding const, avoiding warning.
                Data is in user space, so this is ok. */
            dwoptarg = (char *)eq;
            *argloc = (const char *)eq;
        } else {
            /* Has arg = but arg is empty. */
            dwoptarg = 0;
        }
        return TRUE;
    } else {
        d = strcmp(iplace,dwlopt->name);
        if (d) {
            return FALSE;
        }
        if (dwlopt->has_arg == 1) {
            *argerr = TRUE;
            return TRUE;
        }
        dwoptarg = 0;
        return TRUE;
    }
}

/*  dwgetopt_long
    A reimplemention of  a portion of
    the getopt(3) GNU/Linux  getopt_long().
    See dwgetopt.h for more details.
*/
int dwgetopt_long(int nargc, char *const nargv[],
    const char *ostr,
    const struct dwoption* longopts,
    int *longindex)
{
    char *lplace = 0;
    if (dwoptreset) {
        /*  Not really supported. */
        place = EMSG;
        return (-1);
    }
    if (*place) {
        int v = dwgetopt(nargc,nargv,ostr);
        return v;
    }
    /*  Use local lplace in case we need to call getopt()
        just below. */
    lplace = nargv[dwoptind];
    if (dwoptind >= nargc || *lplace++ != '-') {
        /* Argument is absent or is not an option */
        place = EMSG;
        return (-1);
    }
    if (*lplace  != '-') {
        /* Notice place not  disturbed. */
        int v = dwgetopt(nargc,nargv,ostr);
        return v;
    }
    /*  Starts with two dashes.
        Now we set the global place */
    place = lplace+1;
    if (!*place) {
        /* "--" => end of options */
        ++dwoptind;
        place = EMSG;
        return (-1);
    }

    /* We think this is a longopt. */
    {
    int lo_num = 0;

    for (;;lo_num++) {
        const struct dwoption *dwlopt = longopts +lo_num;
        const char * argloc = 0;
        int argerr = 0;
        int resmatch = 0;

        if (!dwlopt->name) {
            dwoptind++;
            (void)fprintf(stderr,
                "%s: invalid long option '--%s'\n",
                nargv[0]?nargv[0]:"",
                place);
            /* Leave longindex unchanged. */
            place = EMSG;
            return (BADCH);
        }
        resmatch= dwoptnamematches(dwlopt,place,
            &argloc,&argerr);
        if (resmatch) {
            dwoptarg = 0;
            if (argloc) {
                /* Must drop const here. Ugh. */
                dwoptarg = (char *)argloc;
            }
        }
        if (argerr) {
            /*  resmatch  == TRUE

                arg option  missing if required, present
                but not allowed.
                GNU Behavior not well documented.
                Had to experiment.

                if argument-not-allowed, and we have one,
                do ???

                If argument-required,
                then here GNU
                would take the next argv as the argument.
                we are not currently doing that. */
            /**longindex = lo_num; */
            if (dwlopt->has_arg) {
                /*  Missing required arg, this does not
                    match GNU getopt_long behavior
                    of taking next argv as the arg value.
                    and thus making getopt_long succeed. */
                (void)fprintf(stderr,
                    "%s: missing required long option "
                    "argument '--%s'\n",
                    nargv[0]?nargv[0]:"",
                    place);
            } else {
                /* has arg but should not */
                (void)fprintf(stderr,
                    "%s: option '--%s' does not allow an argument\n",
                    nargv[0]?nargv[0]:"",
                    dwlopt->name);
            }
            dwoptind++;
            place = EMSG;
            return (BADCH);
        }
        if (resmatch) {
            *longindex = lo_num;
            place = EMSG;
            dwoptind++;
            return dwlopt->val;
        }
    }
    /* Can never get here */
    place = EMSG;
    dwoptind++;
    return (-1);
    }
}

/*
    * getopt --
    * Parse argc/argv argument vector.
    * a: means
    *     -afoo
    *     -a foo
    *     and 'foo' is returned in dwoptarg
    *  b:: means
    *     -b
    *        and dwoptarg is null
    *     -bother
    *        and dwoptarg is 'other'
    */
int
dwgetopt(int nargc, char * const nargv[], const char *ostr)
{
    char *oli;                      /* option letter list index */

    if (dwoptreset || *place == 0) { /* update scanning pointer */
        dwoptreset = 0;
        place = nargv[dwoptind];

        if (dwoptind >= nargc || *place++ != '-') {
            /* Argument is absent or is not an option */
            place = EMSG;
            return (-1);
        }
        dwoptopt = *place++;
        if (dwoptopt == '-' && *place == 0) {
            /* "--" => end of options */
            ++dwoptind;
            place = EMSG;
            return (-1);
        }
        if (dwoptopt == 0) {
            /* Solitary '-', treat as a '-' option
                if the program (eg su) is looking for it. */
            place = EMSG;
            if (strchr(ostr, '-') == NULL) {
                return -1;
            }
            dwoptopt = '-';
        }
    } else {
        dwoptopt = *place++;
    }
    /* See if option letter is one the caller wanted... */
    if (dwoptopt == ':' || (oli = strchr(ostr, dwoptopt)) == NULL) {
        if (*place == 0) {
            ++dwoptind;
        }
        if (dwopterr && *ostr != ':') {
            (void)fprintf(stderr,
                "%s: invalid option -- '%c'\n",
                nargv[0]?nargv[0]:"",
                dwoptopt);
        }
        return (BADCH);
    }

    /* Does this option need an argument? */
    if (oli[1] != ':') {
        /* don't need argument */
        dwoptarg = NULL;
        if (*place == 0) {
            ++dwoptind;
        }
    } else {
        int reqnextarg = 1;
        if (oli[1] && (oli[2] == ':')) {
            /* Pair of :: means special treatment of dwoptarg */
            reqnextarg = 0;
        }
        /*  Option-argument is either the rest of this argument or the
            entire next argument. */
        if (*place ) {
            /* Whether : or :: */
            dwoptarg = STRIP_OFF_CONSTNESS(place);
        } else if (reqnextarg) {
            /* ! *place */
            if (nargc > (++dwoptind)) {
                dwoptarg = nargv[dwoptind];
            } else {
                place=EMSG;
                /*  Next arg required, but is missing */
                if (*ostr == ':') {
                    /* Leading : in ostr calls for BADARG return. */
                    return (BADARG);
                }
                if (dwopterr) {
                    (void)fprintf(stderr,
                        "%s: option requires an argument. -- '%c'\n",
                        nargv[0]?nargv[0]:"",
                        dwoptopt);
                }
                return (BADCH);
            }
        } else {
            /* ! *place */
            /* The key part of :: treatment. */
            dwoptarg = NULL;
        }
        place = EMSG;
        ++dwoptind;
    }
    return (dwoptopt);  /* return option letter */
}
