locale/FreeBSD/wcsftime.c

   1 /*-
   2  * Copyright (c) 2002 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/locale/wcsftime.c,v 1.6 2009/01/15 20:45:59 rdivacky Exp $");
  29
  30 #include "xlocale_private.h"
  31
  32 #include <errno.h>
  33 #include <limits.h>
  34 #include <stdlib.h>
  35 #include <time.h>
  36 #include <wchar.h>
  37
  38 /*
  39  * Convert date and time to a wide-character string.
  40  *
  41  * This is the wide-character counterpart of strftime(). So that we do not
  42  * have to duplicate the code of strftime(), we convert the format string to
  43  * multibyte, call strftime(), then convert the result back into wide
  44  * characters.
  45  *
  46  * This technique loses in the presence of stateful multibyte encoding if any
  47  * of the conversions in the format string change conversion state. When
  48  * stateful encoding is implemented, we will need to reset the state between
  49  * format specifications in the format string.
  50  */
  51 size_t
  52 wcsftime_l(wchar_t * __restrict wcs, size_t maxsize,
  53     const wchar_t * __restrict format, const struct tm * __restrict timeptr,
  54     locale_t loc)
  55 {
  56         static const mbstate_t initial;
  57         mbstate_t mbs;
  58         char *dst, *sformat;
  59         const char *dstp;
  60         const wchar_t *formatp;
  61         size_t n, sflen;
  62         int sverrno;
  63
  64         NORMALIZE_LOCALE(loc);
  65         sformat = dst = NULL;
  66
  67         /*
  68          * Convert the supplied format string to a multibyte representation
  69          * for strftime(), which only handles single-byte characters.
  70          */
  71         mbs = initial;
  72         formatp = format;
  73         sflen = wcsrtombs_l(NULL, &formatp, 0, &mbs, loc);
  74         if (sflen == (size_t)-1)
  75                 goto error;
  76         if ((sformat = malloc(sflen + 1)) == NULL)
  77                 goto error;
  78         mbs = initial;
  79         wcsrtombs_l(sformat, &formatp, sflen + 1, &mbs, loc);
  80
  81         /*
  82          * Allocate memory for longest multibyte sequence that will fit
  83          * into the caller's buffer and call strftime() to fill it.
  84          * Then, copy and convert the result back into wide characters in
  85          * the caller's buffer.
  86          */
  87         if (SIZE_T_MAX / MB_CUR_MAX_L(loc) <= maxsize) {
  88                 /* maxsize is prepostorously large - avoid int. overflow. */
  89                 errno = EINVAL;
  90                 goto error;
  91         }
  92         if ((dst = malloc(maxsize * MB_CUR_MAX_L(loc))) == NULL)
  93                 goto error;
  94         if (strftime_l(dst, maxsize, sformat, timeptr, loc) == 0)
  95                 goto error;
  96         dstp = dst;
  97         mbs = initial;
  98         n = mbsrtowcs_l(wcs, &dstp, maxsize, &mbs, loc);
  99         if (n == (size_t)-2 || n == (size_t)-1 || dstp != NULL)
 100                 goto error;
 101
 102         free(sformat);
 103         free(dst);
 104         return (n);
 105
 106 error:
 107         sverrno = errno;
 108         free(sformat);
 109         free(dst);
 110         errno = sverrno;
 111         return (0);
 112 }
 113
 114 size_t
 115 wcsftime(wchar_t * __restrict wcs, size_t maxsize,
 116     const wchar_t * __restrict format, const struct tm * __restrict timeptr)
 117 {
 118         return wcsftime_l(wcs, maxsize, format, timeptr, __current_locale());
 119 }