lib/libc/stdio/fgetwc.c

   1 /*-
   2  * Copyright (c) 2002-2004 Tim J. Robbins.
   3  * All rights reserved.
   4  *
   5  * Copyright (c) 2011 The FreeBSD Foundation
   6  * All rights reserved.
   7  * Portions of this software were developed by David Chisnall
   8  * under sponsorship from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: head/lib/libc/stdio/fgetwc.c 234799 2012-04-29 16:28:39Z das $
  32  */
  33
  34
  35 #include "namespace.h"
  36 #include <errno.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <wchar.h>
  40 #include "un-namespace.h"
  41 #include "libc_private.h"
  42 #include "local.h"
  43 #include "mblocal.h"
  44 #include "xlocale_private.h"
  45
  46 /*
  47  * MT-safe version.
  48  */
  49 wint_t
  50 fgetwc_l(FILE *fp, locale_t locale)
  51 {
  52         wint_t r;
  53         FIX_LOCALE(locale);
  54
  55         FLOCKFILE(fp);
  56         ORIENT(fp, 1);
  57         r = __fgetwc(fp, locale);
  58         FUNLOCKFILE(fp);
  59
  60         return (r);
  61 }
  62
  63 wint_t
  64 fgetwc(FILE *fp)
  65 {
  66         return fgetwc_l(fp, __get_locale());
  67 }
  68
  69 /*
  70  * Internal (non-MPSAFE) version of fgetwc().  This version takes an
  71  * mbstate_t argument specifying the initial conversion state.  For
  72  * wide streams, this should always be fp->_mbstate.  On return, *nread
  73  * is set to the number of bytes read.
  74  */
  75 wint_t
  76 __fgetwc_mbs(FILE *fp, mbstate_t *mbs, int *nread, locale_t locale)
  77 {
  78         wchar_t wc;
  79         size_t nconv;
  80         struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
  81
  82         if (fp->pub._r <= 0 && __srefill(fp)) {
  83                 *nread = 0;
  84                 return (WEOF);
  85         }
  86         if (MB_CUR_MAX == 1) {
  87                 /* Fast path for single-byte encodings. */
  88                 wc = *fp->pub._p++;
  89                 fp->pub._r--;
  90                 *nread = 1;
  91                 return (wc);
  92         }
  93         *nread = 0;
  94         do {
  95                 nconv = l->__mbrtowc(&wc, fp->pub._p, fp->pub._r, mbs);
  96                 if (nconv == (size_t)-1)
  97                         break;
  98                 else if (nconv == (size_t)-2)
  99                         continue;
 100                 else if (nconv == 0) {
 101                         fp->pub._p++;
 102                         fp->pub._r--;
 103                         (*nread)++;
 104                         return (L'\0');
 105                 } else {
 106                         fp->pub._p += nconv;
 107                         fp->pub._r -= nconv;
 108                         *nread += nconv;
 109                         return (wc);
 110                 }
 111         } while (__srefill(fp) == 0);
 112         fp->pub._flags |= __SERR;
 113         errno = EILSEQ;
 114         return (WEOF);
 115 }