wcsmbs/mbsrtowcs.c

   1 /* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <gconv.h>
  22 #include <string.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26 #include <assert.h>
  27
  28 #ifndef EILSEQ
  29 # define EILSEQ EINVAL
  30 #endif
  31
  32
  33 /* This is the private state used if PS is NULL.  */
  34 static mbstate_t state;
  35
  36 size_t
  37 __mbsrtowcs (dst, src, len, ps)
  38      wchar_t *dst;
  39      const char **src;
  40      size_t len;
  41      mbstate_t *ps;
  42 {
  43   struct gconv_step_data data;
  44   size_t result = 0;
  45   int status;
  46
  47   /* Tell where we want the result.  */
  48   data.is_last = 1;
  49   data.statep = ps ?: &state;
  50
  51   /* Make sure we use the correct function.  */
  52   update_conversion_ptrs ();
  53
  54   /* We have to handle DST == NULL special.  */
  55   if (dst == NULL)
  56     {
  57       wchar_t buf[64];          /* Just an arbitrary size.  */
  58       size_t inbytes_in = strlen (*src) + 1;
  59       size_t inbytes = inbytes_in;
  60       const char *inbuf = *src;
  61       size_t written;
  62
  63       data.outbuf = (char *) buf;
  64       data.outbufsize = sizeof (buf);
  65       do
  66         {
  67           inbuf += inbytes_in - inbytes;
  68           inbytes_in = inbytes;
  69           data.outbufavail = 0;
  70           written = 0;
  71
  72           status = (*__wcsmbs_gconv_fcts.towc->fct) (__wcsmbs_gconv_fcts.towc,
  73                                                      &data, inbuf, &inbytes,
  74                                                      &written, 0);
  75           result += written;
  76         }
  77       while (status == GCONV_FULL_OUTPUT);
  78
  79       if (status == GCONV_OK && ((wchar_t *) dst)[written - 1] == L'\0')
  80         /* Don't count the NUL character in.  */
  81         --result;
  82     }
  83   else
  84     {
  85       /* This code is based on the safe assumption that all internal
  86          multi-byte encodings use the NUL byte only to mark the end
  87          of the string.  */
  88       size_t inbytes_in = __strnlen (*src, len * MB_CUR_MAX) + 1;
  89       size_t inbytes = inbytes_in;
  90
  91       data.outbuf = (char *) dst;
  92       data.outbufsize = len * sizeof (wchar_t);
  93       data.outbufavail = 0;
  94
  95       status = (*__wcsmbs_gconv_fcts.towc->fct) (__wcsmbs_gconv_fcts.towc,
  96                                                  &data, *src, &inbytes,
  97                                                  &result, 0);
  98
  99       /* We have to determine whether the last character converted
 100          is the NUL character.  */
 101       if (status == GCONV_OK && ((wchar_t *) dst)[result - 1] == L'\0')
 102         {
 103           assert (result > 0);
 104           assert (mbsinit (data.statep));
 105           *src = NULL;
 106           --result;
 107         }
 108       else
 109         *src += inbytes_in - inbytes;
 110     }
 111
 112   /* There must not be any problems with the conversion but illegal input
 113      characters.  */
 114   assert (status == GCONV_OK || status == GCONV_ILLEGAL_INPUT
 115           || status == GCONV_INCOMPLETE_INPUT || status == GCONV_FULL_OUTPUT);
 116
 117   if (status != GCONV_OK && status != GCONV_FULL_OUTPUT)
 118     {
 119       result = (size_t) -1;
 120       __set_errno (EILSEQ);
 121     }
 122
 123   return result;
 124 }
 125 weak_alias (__mbsrtowcs, mbsrtowcs)