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 1.13 2008/04/17 22:17:53 jhb Exp $");
  29
  30 #include "xlocale_private.h"
  31
  32 #include "namespace.h"
  33 #include <errno.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <wchar.h>
  37 #include "un-namespace.h"
  38 #include "libc_private.h"
  39 #include "local.h"
  40 #include "mblocal.h"
  41
  42 /*
  43  * MT-safe version.
  44  */
  45 wint_t
  46 fgetwc(FILE *fp)
  47 {
  48         wint_t r;
  49
  50         FLOCKFILE(fp);
  51         ORIENT(fp, 1);
  52         r = __fgetwc(fp, __current_locale());
  53         FUNLOCKFILE(fp);
  54
  55         return (r);
  56 }
  57
  58 wint_t
  59 fgetwc_l(FILE *fp, locale_t loc)
  60 {
  61         wint_t r;
  62
  63         NORMALIZE_LOCALE(loc);
  64         FLOCKFILE(fp);
  65         ORIENT(fp, 1);
  66         r = __fgetwc(fp, loc);
  67         FUNLOCKFILE(fp);
  68
  69         return (r);
  70 }
  71
  72 /*
  73  * Non-MT-safe version.
  74  */
  75 wint_t
  76 __fgetwc(FILE *fp, locale_t loc)
  77 {
  78         wchar_t wc;
  79         size_t nconv;
  80         struct __xlocale_st_runelocale *xrl = loc->__lc_ctype;
  81         size_t (*__mbrtowc)(wchar_t * __restrict, const char * __restrict, size_t, mbstate_t * __restrict, locale_t) = xrl->__mbrtowc;
  82
  83         if (fp->_r <= 0 && __srefill(fp))
  84                 return (WEOF);
  85         if (xrl->__mb_cur_max == 1) {
  86                 /* Fast path for single-byte encodings. */
  87                 wc = *fp->_p++;
  88                 fp->_r--;
  89                 return (wc);
  90         }
  91         do {
  92                 nconv = __mbrtowc(&wc, fp->_p, fp->_r, &fp->_mbstate, loc);
  93                 if (nconv == (size_t)-1)
  94                         break;
  95                 else if (nconv == (size_t)-2)
  96                         continue;
  97                 else if (nconv == 0) {
  98                         /*
  99                          * Assume that the only valid representation of
 100                          * the null wide character is a single null byte.
 101                          */
 102                         fp->_p++;
 103                         fp->_r--;
 104                         return (L'\0');
 105                 } else {
 106                         fp->_p += nconv;
 107                         fp->_r -= nconv;
 108                         return (wc);
 109                 }
 110         } while (__srefill(fp) == 0);
 111         fp->_flags |= __SERR;
 112         errno = EILSEQ;
 113         return (WEOF);
 114 }