wcsmbs/wcsrtombs.c

   1 /* Copyright (C) 1996-2017 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <dlfcn.h>
  21 #include <errno.h>
  22 #include <stdlib.h>
  23 #include <gconv.h>
  24 #include <wchar.h>
  25 #include <wcsmbsload.h>
  26
  27 #include <sysdep.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 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps)
  39 {
  40   struct __gconv_step_data data;
  41   int status;
  42   size_t result;
  43   struct __gconv_step *tomb;
  44   const struct gconv_fcts *fcts;
  45
  46   /* Tell where we want the result.  */
  47   data.__invocation_counter = 0;
  48   data.__internal_use = 1;
  49   data.__flags = __GCONV_IS_LAST;
  50   data.__statep = ps ?: &state;
  51
  52   /* Get the conversion functions.  */
  53   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  54
  55   /* Get the structure with the function pointers.  */
  56   tomb = fcts->tomb;
  57   __gconv_fct fct = tomb->__fct;
  58 #ifdef PTR_DEMANGLE
  59   if (tomb->__shlib_handle != NULL)
  60     PTR_DEMANGLE (fct);
  61 #endif
  62
  63   /* We have to handle DST == NULL special.  */
  64   if (dst == NULL)
  65     {
  66       mbstate_t temp_state;
  67       unsigned char buf[256];           /* Just an arbitrary value.  */
  68       const wchar_t *srcend = *src + __wcslen (*src) + 1;
  69       const unsigned char *inbuf = (const unsigned char *) *src;
  70       size_t dummy;
  71
  72       temp_state = *data.__statep;
  73       data.__statep = &temp_state;
  74
  75       result = 0;
  76       data.__outbufend = buf + sizeof (buf);
  77
  78       do
  79         {
  80           data.__outbuf = buf;
  81
  82           status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
  83                                       (const unsigned char *) srcend, NULL,
  84                                       &dummy, 0, 1));
  85
  86           /* Count the number of bytes.  */
  87           result += data.__outbuf - buf;
  88         }
  89       while (status == __GCONV_FULL_OUTPUT);
  90
  91       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  92         {
  93           /* There better should be a NUL byte at the end.  */
  94           assert (data.__outbuf[-1] == '\0');
  95           /* Don't count the NUL character in.  */
  96           --result;
  97         }
  98     }
  99   else
 100     {
 101       /* This code is based on the safe assumption that all internal
 102          multi-byte encodings use the NUL byte only to mark the end
 103          of the string.  */
 104       const wchar_t *srcend = *src + __wcsnlen (*src, len) + 1;
 105       size_t dummy;
 106
 107       data.__outbuf = (unsigned char *) dst;
 108       data.__outbufend = (unsigned char *) dst + len;
 109
 110       status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
 111                                   (const unsigned char *) srcend, NULL,
 112                                   &dummy, 0, 1));
 113
 114       /* Count the number of bytes.  */
 115       result = data.__outbuf - (unsigned char *) dst;
 116
 117       /* We have to determine whether the last character converted
 118          is the NUL character.  */
 119       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 120           && data.__outbuf[-1] == '\0')
 121         {
 122           assert (data.__outbuf != (unsigned char *) dst);
 123           assert (__mbsinit (data.__statep));
 124           *src = NULL;
 125           --result;
 126         }
 127     }
 128
 129   /* There must not be any problems with the conversion but illegal input
 130      characters.  */
 131   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 132           || status == __GCONV_ILLEGAL_INPUT
 133           || status == __GCONV_INCOMPLETE_INPUT
 134           || status == __GCONV_FULL_OUTPUT);
 135
 136   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 137       && status != __GCONV_EMPTY_INPUT)
 138     {
 139       result = (size_t) -1;
 140       __set_errno (EILSEQ);
 141     }
 142
 143   return result;
 144 }
 145 weak_alias (__wcsrtombs, wcsrtombs)