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 <stdlib.h>
  23 #include <string.h>
  24 #include <wchar.h>
  25 #include <wcsmbsload.h>
  26
  27 #include <assert.h>
  28
  29 #ifndef EILSEQ
  30 # define EILSEQ EINVAL
  31 #endif
  32
  33
  34 /* This is the private state used if PS is NULL.  */
  35 static mbstate_t state;
  36
  37 size_t
  38 __mbsrtowcs (dst, src, len, ps)
  39      wchar_t *dst;
  40      const char **src;
  41      size_t len;
  42      mbstate_t *ps;
  43 {
  44   struct gconv_step_data data;
  45   size_t result = 0;
  46   int status;
  47
  48   /* Tell where we want the result.  */
  49   data.is_last = 1;
  50   data.statep = ps ?: &state;
  51
  52   /* Make sure we use the correct function.  */
  53   update_conversion_ptrs ();
  54
  55   /* We have to handle DST == NULL special.  */
  56   if (dst == NULL)
  57     {
  58       wchar_t buf[64];          /* Just an arbitrary size.  */
  59       const char *srcend = *src + strlen (*src) + 1;
  60       const char *inbuf = *src;
  61
  62       data.outbufend = data.outbuf + sizeof (buf);
  63       do
  64         {
  65           data.outbuf = (char *) buf;
  66
  67           status = (*__wcsmbs_gconv_fcts.towc->fct) (__wcsmbs_gconv_fcts.towc,
  68                                                      &data, &inbuf, srcend,
  69                                                      &result, 0);
  70         }
  71       while (status == GCONV_FULL_OUTPUT);
  72
  73       if (status == GCONV_OK || status == GCONV_EMPTY_INPUT)
  74         {
  75           /* There better should be a NUL wide char at the end.  */
  76           assert (((wchar_t *) data.outbuf)[-1] == L'\0');
  77           /* Don't count the NUL character in.  */
  78           --result;
  79         }
  80     }
  81   else
  82     {
  83       /* This code is based on the safe assumption that all internal
  84          multi-byte encodings use the NUL byte only to mark the end
  85          of the string.  */
  86       const char *srcend = *src + __strnlen (*src, len * MB_CUR_MAX) + 1;
  87
  88       data.outbuf = (char *) dst;
  89       data.outbufend = data.outbuf + len * sizeof (wchar_t);
  90
  91       status = (*__wcsmbs_gconv_fcts.towc->fct) (__wcsmbs_gconv_fcts.towc,
  92                                                  &data, src, srcend,
  93                                                  &result, 0);
  94
  95       /* We have to determine whether the last character converted
  96          is the NUL character.  */
  97       if ((status == GCONV_OK || status == GCONV_EMPTY_INPUT)
  98           && ((wchar_t *) dst)[result - 1] == L'\0')
  99         {
 100           assert (result > 0);
 101           assert (__mbsinit (data.statep));
 102           *src = NULL;
 103           --result;
 104         }
 105     }
 106
 107   /* There must not be any problems with the conversion but illegal input
 108      characters.  */
 109   assert (status == GCONV_OK || status == GCONV_EMPTY_INPUT
 110           || status == GCONV_ILLEGAL_INPUT
 111           || status == GCONV_INCOMPLETE_INPUT || status == GCONV_FULL_OUTPUT);
 112
 113   if (status != GCONV_OK && status != GCONV_FULL_OUTPUT
 114       && status != GCONV_EMPTY_INPUT)
 115     {
 116       result = (size_t) -1;
 117       __set_errno (EILSEQ);
 118     }
 119
 120   return result;
 121 }
 122 weak_alias (__mbsrtowcs, mbsrtowcs)