wcsmbs/wcsnrtombs.c

   1 /* Copyright (C) 1996-2015 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
  60   if (nwc == 0)
  61     return 0;
  62   srcend = *src + __wcsnlen (*src, nwc - 1) + 1;
  63
  64   /* Get the conversion functions.  */
  65   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
  66
  67   /* Get the structure with the function pointers.  */
  68   tomb = fcts->tomb;
  69   __gconv_fct fct = tomb->__fct;
  70 #ifdef PTR_DEMANGLE
  71   if (tomb->__shlib_handle != NULL)
  72     PTR_DEMANGLE (fct);
  73 #endif
  74
  75   /* We have to handle DST == NULL special.  */
  76   if (dst == NULL)
  77     {
  78       mbstate_t temp_state;
  79       unsigned char buf[256];           /* Just an arbitrary value.  */
  80       const unsigned char *inbuf = (const unsigned char *) *src;
  81       size_t dummy;
  82
  83       temp_state = *data.__statep;
  84       data.__statep = &temp_state;
  85
  86       result = 0;
  87       data.__outbufend = buf + sizeof (buf);
  88
  89       do
  90         {
  91           data.__outbuf = buf;
  92
  93           status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
  94                                       (const unsigned char *) srcend, NULL,
  95                                       &dummy, 0, 1));
  96
  97           /* Count the number of bytes.  */
  98           result += data.__outbuf - buf;
  99         }
 100       while (status == __GCONV_FULL_OUTPUT);
 101
 102       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 103           && data.__outbuf[-1] == '\0')
 104         /* Don't count the NUL character in.  */
 105         --result;
 106     }
 107   else
 108     {
 109       /* This code is based on the safe assumption that all internal
 110          multi-byte encodings use the NUL byte only to mark the end
 111          of the string.  */
 112       size_t dummy;
 113
 114       data.__outbuf = (unsigned char *) dst;
 115       data.__outbufend = (unsigned char *) dst + len;
 116
 117       status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
 118                                   (const unsigned char *) srcend, NULL,
 119                                   &dummy, 0, 1));
 120
 121       /* Count the number of bytes.  */
 122       result = data.__outbuf - (unsigned char *) dst;
 123
 124       /* We have to determine whether the last character converted
 125          is the NUL character.  */
 126       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 127           && data.__outbuf[-1] == '\0')
 128         {
 129           assert (data.__outbuf != (unsigned char *) dst);
 130           assert (__mbsinit (data.__statep));
 131           *src = NULL;
 132           --result;
 133         }
 134     }
 135
 136   /* There must not be any problems with the conversion but illegal input
 137      characters.  */
 138   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 139           || status == __GCONV_ILLEGAL_INPUT
 140           || status == __GCONV_INCOMPLETE_INPUT
 141           || status == __GCONV_FULL_OUTPUT);
 142
 143   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 144       && status != __GCONV_EMPTY_INPUT)
 145     {
 146       result = (size_t) -1;
 147       __set_errno (EILSEQ);
 148     }
 149
 150   return result;
 151 }
 152 weak_alias (__wcsnrtombs, wcsnrtombs)