stdio/FreeBSD/fgetwc.c

   1 /*-
   2  * Copyright (c) 2002-2004 Tim J. Robbins.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD: src/lib/libc/stdio/fgetwc.c,v 1.12 2004/07/20 08:27:27 tjr Exp $");
  29
  30 #include "namespace.h"
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <wchar.h>
  35 #include "un-namespace.h"
  36 #include "libc_private.h"
  37 #include "local.h"
  38 #include "mblocal.h"
  39
  40 /*
  41  * MT-safe version.
  42  */
  43 wint_t
  44 fgetwc(FILE *fp)
  45 {
  46         wint_t r;
  47
  48         FLOCKFILE(fp);
  49         ORIENT(fp, 1);
  50         r = __fgetwc(fp);
  51         FUNLOCKFILE(fp);
  52
  53         return (r);
  54 }
  55
  56 /*
  57  * Non-MT-safe version.
  58  */
  59 wint_t
  60 __fgetwc(FILE *fp)
  61 {
  62         wchar_t wc;
  63         size_t nconv;
  64
  65         if (fp->_r <= 0 && __srefill(fp))
  66                 return (WEOF);
  67         if (MB_CUR_MAX == 1) {
  68                 /* Fast path for single-byte encodings. */
  69                 wc = *fp->_p++;
  70                 fp->_r--;
  71                 return (wc);
  72         }
  73         do {
  74                 nconv = __mbrtowc(&wc, fp->_p, fp->_r, &fp->_extra->mbstate);
  75                 if (nconv == (size_t)-1)
  76                         break;
  77                 else if (nconv == (size_t)-2)
  78                         continue;
  79                 else if (nconv == 0) {
  80                         /*
  81                          * Assume that the only valid representation of
  82                          * the null wide character is a single null byte.
  83                          */
  84                         fp->_p++;
  85                         fp->_r--;
  86                         return (L'\0');
  87                 } else {
  88                         fp->_p += nconv;
  89                         fp->_r -= nconv;
  90                         return (wc);
  91                 }
  92         } while (__srefill(fp) == 0);
  93         fp->_flags |= __SERR;
  94         errno = EILSEQ;
  95         return (WEOF);
  96 }