/*      $OpenBSD: fgetwc.c,v 1.7 2025/08/08 15:58:53 yasuoka Exp $      */
/* $NetBSD: fgetwc.c,v 1.3 2003/03/07 07:11:36 tshiozak Exp $ */

/*-
 * Copyright (c)2001 Citrus Project,
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 *
 * $Citrus$
 */

#include <errno.h>
#include <stdio.h>
#include <wchar.h>
#include "local.h"

wint_t
__fgetwc_unlock(FILE *fp)
{
        wchar_t wc;
        size_t size;

        _SET_ORIENTATION(fp, 1);

        /* if there're ungetwc'ed wchars, use them */
        if (fp->_ungetwc_inbuf) {
                wc = fp->_ungetwc_buf[--fp->_ungetwc_inbuf];

                return wc;
        }

        do {
                char c;
                int ch = __sgetc(fp);

                if (ch == EOF) {
                        return WEOF;
                }

                c = ch;
                size = mbrtowc(&wc, &c, 1, &fp->_mbstate_in);
                if (size == (size_t)-1) {
                        fp->_flags |= __SERR;
                        return WEOF;
                }
        } while (size == (size_t)-2);

        return wc;
}

wint_t
fgetwc(FILE *fp)
{
        wint_t r;

        FLOCKFILE(fp);
        r = __fgetwc_unlock(fp);
        FUNLOCKFILE(fp);

        return (r);
}
DEF_STRONG(fgetwc);