wcsmbs/mbsrtowcs.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.org>, 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   struct __gconv_step *towc;
  48
  49   /* Tell where we want the result.  */
  50   data.__invocation_counter = 0;
  51   data.__internal_use = 1;
  52   data.__is_last = 1;
  53   data.__statep = ps ?: &state;
  54
  55   /* Make sure we use the correct function.  */
  56   update_conversion_ptrs ();
  57
  58   /* Get the structure with the function pointers.  */
  59   towc = __wcsmbs_gconv_fcts.towc;
  60
  61   /* We have to handle DST == NULL special.  */
  62   if (dst == NULL)
  63     {
  64       wchar_t buf[64];          /* Just an arbitrary size.  */
  65       const unsigned char *inbuf = (const unsigned char *) *src;
  66       const unsigned char *srcend = inbuf + strlen (inbuf) + 1;
  67
  68       data.__outbufend = (char *) buf + sizeof (buf);
  69       do
  70         {
  71           data.__outbuf = (char *) buf;
  72
  73           status = (*towc->__fct) (__wcsmbs_gconv_fcts.towc, &data, &inbuf,
  74                                    srcend, &result, 0);
  75         }
  76       while (status == __GCONV_FULL_OUTPUT);
  77
  78       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  79         {
  80           /* There better should be a NUL wide char at the end.  */
  81           assert (((wchar_t *) data.__outbuf)[-1] == L'\0');
  82           /* Don't count the NUL character in.  */
  83           --result;
  84         }
  85     }
  86   else
  87     {
  88       /* This code is based on the safe assumption that all internal
  89          multi-byte encodings use the NUL byte only to mark the end
  90          of the string.  */
  91       const unsigned char *srcend;
  92
  93       srcend = (const unsigned char *) (*src
  94                                         + __strnlen (*src, len * MB_CUR_MAX)
  95                                         + 1);
  96
  97       data.__outbuf = (unsigned char *) dst;
  98       data.__outbufend = data.__outbuf + len * sizeof (wchar_t);
  99
 100       status = (*towc->__fct) (__wcsmbs_gconv_fcts.towc, &data,
 101                                (const unsigned char **) src, srcend,
 102                                &result, 0);
 103
 104       /* We have to determine whether the last character converted
 105          is the NUL character.  */
 106       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 107           && ((wchar_t *) dst)[result - 1] == L'\0')
 108         {
 109           assert (result > 0);
 110           assert (__mbsinit (data.__statep));
 111           *src = NULL;
 112           --result;
 113         }
 114     }
 115
 116   /* There must not be any problems with the conversion but illegal input
 117      characters.  */
 118   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 119           || status == __GCONV_ILLEGAL_INPUT
 120           || status == __GCONV_INCOMPLETE_INPUT
 121           || status == __GCONV_FULL_OUTPUT);
 122
 123   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 124       && status != __GCONV_EMPTY_INPUT)
 125     {
 126       result = (size_t) -1;
 127       __set_errno (EILSEQ);
 128     }
 129
 130   return result;
 131 }
 132 weak_alias (__mbsrtowcs, mbsrtowcs)