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      1 /*   $NetBSD: wcsftime.c,v 1.2 2006/10/04 14:19:16 tnozaki Exp $  */
      2 /*-
      3  * Copyright (c) 2002 Tim J. Robbins
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     25  * SUCH DAMAGE.
     26  */
     27 #include  <LibConfig.h>
     28 #include  <sys/EfiCdefs.h>
     29 #if defined(LIBC_SCCS) && !defined(lint)
     30 #if 0
     31 __FBSDID("$FreeBSD: src/lib/libc/locale/wcsftime.c,v 1.4 2004/04/07 09:47:56 tjr Exp $");
     32 #else
     33 __RCSID("$NetBSD: wcsftime.c,v 1.2 2006/10/04 14:19:16 tnozaki Exp $");
     34 #endif
     35 #endif /* LIBC_SCCS and not lint */
     36 
     37 #include <errno.h>
     38 #include <limits.h>
     39 #include <stdlib.h>
     40 #include <time.h>
     41 #include <wchar.h>
     42 #include  <machine/int_limits.h>
     43 
     44 /*
     45  * Convert date and time to a wide-character string.
     46  *
     47  * This is the wide-character counterpart of strftime(). So that we do not
     48  * have to duplicate the code of strftime(), we convert the format string to
     49  * multibyte, call strftime(), then convert the result back into wide
     50  * characters.
     51  *
     52  * This technique loses in the presence of stateful multibyte encoding if any
     53  * of the conversions in the format string change conversion state. When
     54  * stateful encoding is implemented, we will need to reset the state between
     55  * format specifications in the format string.
     56  */
     57 size_t
     58 wcsftime(wchar_t *wcs, size_t maxsize,
     59     const wchar_t *format, const struct tm *timeptr)
     60 {
     61   char *dst, *dstp, *sformat;
     62   size_t n, sflen;
     63   int sverrno;
     64 
     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   sflen = wcstombs(NULL, format, 0);
     72   if (sflen == (size_t)-1)
     73     goto error;
     74   if ((sformat = malloc(sflen + 1)) == NULL)
     75     goto error;
     76   wcstombs(sformat, format, sflen + 1);
     77 
     78   /*
     79    * Allocate memory for longest multibyte sequence that will fit
     80    * into the caller's buffer and call strftime() to fill it.
     81    * Then, copy and convert the result back into wide characters in
     82    * the caller's buffer.
     83    */
     84   if (SIZE_T_MAX / MB_CUR_MAX <= maxsize) {
     85     /* maxsize is preposturously large - avoid int. overflow. */
     86     errno = EINVAL;
     87     goto error;
     88   }
     89   dst = malloc(maxsize * MB_CUR_MAX);
     90   if (dst == NULL)
     91     goto error;
     92   if (strftime(dst, maxsize, sformat, timeptr) == 0)
     93     goto error;
     94   dstp = dst;
     95   n = mbstowcs(wcs, dstp, maxsize);
     96   if (n == (size_t)-2 || n == (size_t)-1)
     97     goto error;
     98 
     99   free(sformat);
    100   free(dst);
    101   return n;
    102 
    103 error:
    104   sverrno = errno;
    105   free(sformat);
    106   free(dst);
    107   errno = sverrno;
    108   return 0;
    109 }
    110