wcsmbs/wcsrtombs.c

   1 /* Copyright (C) 1996-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <assert.h>
  19 #include <dlfcn.h>
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include <gconv.h>
  23 #include <wchar.h>
  24 #include <wcsmbsload.h>
  25
  26 #include <sysdep.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 __wcsrtombs (char *dst, const wchar_t **src, size_t len, mbstate_t *ps)
  38 {
  39   struct __gconv_step_data data;
  40   int status;
  41   size_t result;
  42   struct __gconv_step *tomb;
  43   const struct gconv_fcts *fcts;
  44
  45   /* Tell where we want the result.  */
  46   data.__invocation_counter = 0;
  47   data.__internal_use = 1;
  48   data.__flags = __GCONV_IS_LAST;
  49   data.__statep = ps ?: &state;
  50
  51   /* Get the conversion functions.  */
  52   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  53
  54   /* Get the structure with the function pointers.  */
  55   tomb = fcts->tomb;
  56   __gconv_fct fct = tomb->__fct;
  57 #ifdef PTR_DEMANGLE
  58   if (tomb->__shlib_handle != NULL)
  59     PTR_DEMANGLE (fct);
  60 #endif
  61
  62   /* We have to handle DST == NULL special.  */
  63   if (dst == NULL)
  64     {
  65       mbstate_t temp_state;
  66       unsigned char buf[256];           /* Just an arbitrary value.  */
  67       const wchar_t *srcend = *src + __wcslen (*src) + 1;
  68       const unsigned char *inbuf = (const unsigned char *) *src;
  69       size_t dummy;
  70
  71       temp_state = *data.__statep;
  72       data.__statep = &temp_state;
  73
  74       result = 0;
  75       data.__outbufend = buf + sizeof (buf);
  76
  77       do
  78         {
  79           data.__outbuf = buf;
  80
  81           status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
  82                                       (const unsigned char *) srcend, NULL,
  83                                       &dummy, 0, 1));
  84
  85           /* Count the number of bytes.  */
  86           result += data.__outbuf - buf;
  87         }
  88       while (status == __GCONV_FULL_OUTPUT);
  89
  90       if (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  91         {
  92           /* There better should be a NUL byte at the end.  */
  93           assert (data.__outbuf[-1] == '\0');
  94           /* Don't count the NUL character in.  */
  95           --result;
  96         }
  97     }
  98   else
  99     {
 100       /* This code is based on the safe assumption that all internal
 101          multi-byte encodings use the NUL byte only to mark the end
 102          of the string.  */
 103       const wchar_t *srcend = *src + __wcsnlen (*src, len) + 1;
 104       size_t dummy;
 105
 106       data.__outbuf = (unsigned char *) dst;
 107       data.__outbufend = (unsigned char *) dst + len;
 108
 109       status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
 110                                   (const unsigned char *) srcend, NULL,
 111                                   &dummy, 0, 1));
 112
 113       /* Count the number of bytes.  */
 114       result = data.__outbuf - (unsigned char *) dst;
 115
 116       /* We have to determine whether the last character converted
 117          is the NUL character.  */
 118       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 119           && data.__outbuf[-1] == '\0')
 120         {
 121           assert (data.__outbuf != (unsigned char *) dst);
 122           assert (__mbsinit (data.__statep));
 123           *src = NULL;
 124           --result;
 125         }
 126     }
 127
 128   /* There must not be any problems with the conversion but illegal input
 129      characters.  */
 130   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 131           || status == __GCONV_ILLEGAL_INPUT
 132           || status == __GCONV_INCOMPLETE_INPUT
 133           || status == __GCONV_FULL_OUTPUT);
 134
 135   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 136       && status != __GCONV_EMPTY_INPUT)
 137     {
 138       result = (size_t) -1;
 139       __set_errno (EILSEQ);
 140     }
 141
 142   return result;
 143 }
 144 weak_alias (__wcsrtombs, wcsrtombs)