wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996-2014 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 <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 /* This is a non-standard function but it is very useful in the
  37    implementation of stdio because we have to deal with unterminated
  38    buffers.  At most NWC wide character will be converted.  */
  39 size_t
  40 __wcsnrtombs (dst, src, nwc, len, ps)
  41      char *dst;
  42      const wchar_t **src;
  43      size_t nwc;
  44      size_t len;
  45      mbstate_t *ps;
  46 {
  47   struct __gconv_step_data data;
  48   const wchar_t *srcend;
  49   int status;
  50   size_t result;
  51   struct __gconv_step *tomb;
  52   const struct gconv_fcts *fcts;
  53
  54   /* Tell where we want the result.  */
  55   data.__invocation_counter = 0;
  56   data.__internal_use = 1;
  57   data.__flags = __GCONV_IS_LAST;
  58   data.__statep = ps ?: &state;
  59   data.__trans = NULL;
  60
  61   if (nwc == 0)
  62     return 0;
  63   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  64
  65   /* Get the conversion functions.  */
  66   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  67
  68   /* Get the structure with the function pointers.  */
  69   tomb = fcts->tomb;
  70   __gconv_fct fct = tomb->__fct;
  71 #ifdef PTR_DEMANGLE
  72   if (tomb->__shlib_handle != NULL)
  73     PTR_DEMANGLE (fct);
  74 #endif
  75
  76   /* We have to handle DST == NULL special.  */
  77   if (dst == NULL)
  78     {
  79       mbstate_t temp_state;
  80       unsigned char buf[256];           /* Just an arbitrary value.  */
  81       const unsigned char *inbuf = (const unsigned char *) *src;
  82       size_t dummy;
  83
  84       temp_state = *data.__statep;
  85       data.__statep = &temp_state;
  86
  87       result = 0;
  88       data.__outbufend = buf + sizeof (buf);
  89
  90       do
  91         {
  92           data.__outbuf = buf;
  93
  94           status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
  95                                       (const unsigned char *) srcend, NULL,
  96                                       &dummy, 0, 1));
  97
  98           /* Count the number of bytes.  */
  99           result += data.__outbuf - buf;
 100         }
 101       while (status == __GCONV_FULL_OUTPUT);
 102
 103       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 104           && data.__outbuf[-1] == '\0')
 105         /* Don't count the NUL character in.  */
 106         --result;
 107     }
 108   else
 109     {
 110       /* This code is based on the safe assumption that all internal
 111          multi-byte encodings use the NUL byte only to mark the end
 112          of the string.  */
 113       size_t dummy;
 114
 115       data.__outbuf = (unsigned char *) dst;
 116       data.__outbufend = (unsigned char *) dst + len;
 117
 118       status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
 119                                   (const unsigned char *) srcend, NULL,
 120                                   &dummy, 0, 1));
 121
 122       /* Count the number of bytes.  */
 123       result = data.__outbuf - (unsigned char *) dst;
 124
 125       /* We have to determine whether the last character converted
 126          is the NUL character.  */
 127       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 128           && data.__outbuf[-1] == '\0')
 129         {
 130           assert (data.__outbuf != (unsigned char *) dst);
 131           assert (__mbsinit (data.__statep));
 132           *src = NULL;
 133           --result;
 134         }
 135     }
 136
 137   /* There must not be any problems with the conversion but illegal input
 138      characters.  */
 139   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 140           || status == __GCONV_ILLEGAL_INPUT
 141           || status == __GCONV_INCOMPLETE_INPUT
 142           || status == __GCONV_FULL_OUTPUT);
 143
 144   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 145       && status != __GCONV_EMPTY_INPUT)
 146     {
 147       result = (size_t) -1;
 148       __set_errno (EILSEQ);
 149     }
 150
 151   return result;
 152 }
 153 weak_alias (__wcsnrtombs, wcsnrtombs)