wcsmbs/mbsnrtowcs.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2000 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 <dlfcn.h>
  21 #include <errno.h>
  22 #include <gconv.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 /* This is a non-standard function but it is very useful in the
  38    implementation of stdio because we have to deal with unterminated
  39    buffers.  At most NMC bytes will be converted.  */
  40 size_t
  41 __mbsnrtowcs (dst, src, nmc, len, ps)
  42      wchar_t *dst;
  43      const char **src;
  44      size_t nmc;
  45      size_t len;
  46      mbstate_t *ps;
  47 {
  48   const unsigned char *srcend;
  49   struct __gconv_step_data data;
  50   size_t result;
  51   int status;
  52   struct __gconv_step *towc;
  53   size_t dummy;
  54
  55   /* Tell where we want the result.  */
  56   data.__invocation_counter = 0;
  57   data.__internal_use = 1;
  58   data.__flags = __GCONV_IS_LAST;
  59   data.__statep = ps ?: &state;
  60
  61   if (nmc == 0)
  62     return 0;
  63   srcend = *src + __strnlen (*src, nmc - 1) + 1;
  64
  65   /* Make sure we use the correct function.  */
  66   update_conversion_ptrs ();
  67
  68   /* Get the structure with the function pointers.  */
  69   towc = __wcsmbs_gconv_fcts.towc;
  70
  71   /* We have to handle DST == NULL special.  */
  72   if (dst == NULL)
  73     {
  74       wchar_t buf[64];          /* Just an arbitrary size.  */
  75       const unsigned char *inbuf = *src;
  76
  77       result = 0;
  78       data.__outbufend = (unsigned char *) buf + sizeof (buf);
  79       do
  80         {
  81           data.__outbuf = (unsigned char *) buf;
  82
  83           status = DL_CALL_FCT (towc->__fct,
  84                                 (towc, &data, &inbuf, srcend, data.__outbuf,
  85                                  &dummy, 0, 1));
  86
  87           result += (wchar_t *) data.__outbuf - buf;
  88         }
  89       while (status == __GCONV_FULL_OUTPUT);
  90
  91       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
  92           && ((wchar_t *) data.__outbuf)[-1] == L'\0')
  93         /* Don't count the NUL character in.  */
  94         --result;
  95     }
  96   else
  97     {
  98       /* This code is based on the safe assumption that all internal
  99          multi-byte encodings use the NUL byte only to mark the end
 100          of the string.  */
 101       data.__outbuf = (unsigned char *) dst;
 102       data.__outbufend = data.__outbuf + len * sizeof (wchar_t);
 103
 104       status = DL_CALL_FCT (towc->__fct,
 105                             (towc, &data, (const unsigned char **) src, srcend,
 106                              data.__outbuf, &dummy, 0, 1));
 107
 108       result = (wchar_t *) data.__outbuf - dst;
 109
 110       /* We have to determine whether the last character converted
 111          is the NUL character.  */
 112       if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
 113           && (assert (result > 0),
 114               ((wchar_t *) dst)[result - 1] == L'\0'))
 115         {
 116           assert (__mbsinit (data.__statep));
 117           *src = NULL;
 118           --result;
 119         }
 120     }
 121
 122   /* There must not be any problems with the conversion but illegal input
 123      characters.  */
 124   assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
 125           || status == __GCONV_ILLEGAL_INPUT
 126           || status == __GCONV_INCOMPLETE_INPUT
 127           || status == __GCONV_FULL_OUTPUT);
 128
 129   if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
 130       && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)
 131     {
 132       result = (size_t) -1;
 133       __set_errno (EILSEQ);
 134     }
 135
 136   return result;
 137 }
 138 weak_alias (__mbsnrtowcs, mbsnrtowcs)