lib/wcsnrtombs-impl.h

   1 /* Convert wide string to string.
   2    Copyright (C) 2008-2024 Free Software Foundation, Inc.
   3    Written by Bruno Haible <bruno@clisp.org>, 2008.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation, either version 3 of the
   8    License, or (at your option) any later version.
   9
  10    This file is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 size_t
  19 FUNC (char *dest, const SCHAR_T **srcp, size_t srclen, size_t len, mbstate_t *ps)
  20 {
  21   if (ps == NULL)
  22     ps = &INTERNAL_STATE;
  23   {
  24     const SCHAR_T *src = *srcp;
  25     size_t cur_max = MB_CUR_MAX;
  26     char buf[64];
  27
  28     if (!(cur_max <= sizeof (buf)))
  29       abort ();
  30
  31     if (dest != NULL)
  32       {
  33         char *destptr = dest;
  34
  35         for (; srclen > 0 && len > 0; src++, srclen--)
  36           {
  37             SCHAR_T wc = *src;
  38             size_t ret = WCRTOMB (len >= cur_max ? destptr : buf, wc, ps);
  39
  40             if (ret == (size_t)(-1))
  41               goto bad_input;
  42             if (!(ret <= cur_max))
  43               abort ();
  44             if (len < ret)
  45               break;
  46             if (len < cur_max)
  47               memcpy (destptr, buf, ret);
  48             if (wc == 0)
  49               {
  50                 src = NULL;
  51                 /* Here mbsinit (ps).  */
  52                 break;
  53               }
  54             destptr += ret;
  55             len -= ret;
  56           }
  57         *srcp = src;
  58         return destptr - dest;
  59       }
  60     else
  61       {
  62         /* Ignore dest and len, don't store *srcp at the end, and
  63            don't clobber *ps.  */
  64         mbstate_t state = *ps;
  65         size_t totalcount = 0;
  66
  67         for (; srclen > 0; src++, srclen--)
  68           {
  69             SCHAR_T wc = *src;
  70             size_t ret = WCRTOMB (buf, wc, &state);
  71
  72             if (ret == (size_t)(-1))
  73               goto bad_input2;
  74             if (wc == 0)
  75               {
  76                 /* Here mbsinit (&state).  */
  77                 break;
  78               }
  79             totalcount += ret;
  80           }
  81         return totalcount;
  82       }
  83
  84    bad_input:
  85     *srcp = src;
  86    bad_input2:
  87     errno = EILSEQ;
  88     return (size_t)(-1);
  89   }
  90 }