about summary refs log tree commit diff
path: root/wcsmbs/mbsnrtowcs.c
blob: 238458d25d5cce8891c5c79dfe564ac5dfbb56ee (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/* Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <dlfcn.h>
#include <errno.h>
#include <gconv.h>
#include <string.h>
#include <wchar.h>
#include <wcsmbsload.h>

#include <assert.h>

#ifndef EILSEQ
# define EILSEQ EINVAL
#endif


/* This is the private state used if PS is NULL.  */
static mbstate_t state;

/* This is a non-standard function but it is very useful in the
   implementation of stdio because we have to deal with unterminated
   buffers.  At most NMC bytes will be converted.  */
size_t
__mbsnrtowcs (dst, src, nmc, len, ps)
     wchar_t *dst;
     const char **src;
     size_t nmc;
     size_t len;
     mbstate_t *ps;
{
  const unsigned char *srcend;
  struct __gconv_step_data data;
  size_t result;
  int status;
  struct __gconv_step *towc;
  size_t dummy;

  /* Tell where we want the result.  */
  data.__invocation_counter = 0;
  data.__internal_use = 1;
  data.__flags = __GCONV_IS_LAST;
  data.__statep = ps ?: &state;

  if (nmc == 0)
    return 0;
  srcend = *src + __strnlen (*src, nmc - 1) + 1;

  /* Make sure we use the correct function.  */
  update_conversion_ptrs ();

  /* Get the structure with the function pointers.  */
  towc = __wcsmbs_gconv_fcts.towc;

  /* We have to handle DST == NULL special.  */
  if (dst == NULL)
    {
      wchar_t buf[64];		/* Just an arbitrary size.  */
      const unsigned char *inbuf = *src;

      result = 0;
      data.__outbufend = (unsigned char *) buf + sizeof (buf);
      do
	{
	  data.__outbuf = (unsigned char *) buf;

	  status = DL_CALL_FCT (towc->__fct,
				(towc, &data, &inbuf, srcend, data.__outbuf,
				 &dummy, 0, 1));

	  result += (wchar_t *) data.__outbuf - buf;
	}
      while (status == __GCONV_FULL_OUTPUT);

      if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
	  && ((wchar_t *) data.__outbuf)[-1] == L'\0')
	/* Don't count the NUL character in.  */
	--result;
    }
  else
    {
      /* This code is based on the safe assumption that all internal
	 multi-byte encodings use the NUL byte only to mark the end
	 of the string.  */
      data.__outbuf = (unsigned char *) dst;
      data.__outbufend = data.__outbuf + len * sizeof (wchar_t);

      status = DL_CALL_FCT (towc->__fct,
			    (towc, &data, (const unsigned char **) src, srcend,
			     data.__outbuf, &dummy, 0, 1));

      result = (wchar_t *) data.__outbuf - dst;

      /* We have to determine whether the last character converted
	 is the NUL character.  */
      if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
	  && (assert (result > 0),
	      ((wchar_t *) dst)[result - 1] == L'\0'))
	{
	  assert (__mbsinit (data.__statep));
	  *src = NULL;
	  --result;
	}
    }

  /* There must not be any problems with the conversion but illegal input
     characters.  */
  assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT
	  || status == __GCONV_ILLEGAL_INPUT
	  || status == __GCONV_INCOMPLETE_INPUT
	  || status == __GCONV_FULL_OUTPUT);

  if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
      && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)
    {
      result = (size_t) -1;
      __set_errno (EILSEQ);
    }

  return result;
}
weak_alias (__mbsnrtowcs, mbsnrtowcs)