about summary refs log tree commit diff
path: root/wcsmbs/wcsnrtombs.c
blob: 12b116a837c4b437aff02d7a5aa9704b6720854d (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
139
140
141
142
143
144
145
/* Copyright (C) 1996-2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

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

#include <pointer_guard.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 NWC wide character will be converted.  */
size_t
__wcsnrtombs (char *dst, const wchar_t **src, size_t nwc, size_t len,
	      mbstate_t *ps)
{
  struct __gconv_step_data data;
  const wchar_t *srcend;
  int status;
  size_t result;
  struct __gconv_step *tomb;
  const struct gconv_fcts *fcts;

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

  if (nwc == 0)
    return 0;
  srcend = *src + __wcsnlen (*src, nwc - 1) + 1;

  /* Get the conversion functions.  */
  fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));

  /* Get the structure with the function pointers.  */
  tomb = fcts->tomb;
  __gconv_fct fct = tomb->__fct;
  if (tomb->__shlib_handle != NULL)
    PTR_DEMANGLE (fct);

  /* We have to handle DST == NULL special.  */
  if (dst == NULL)
    {
      mbstate_t temp_state;
      unsigned char buf[256];		/* Just an arbitrary value.  */
      const unsigned char *inbuf = (const unsigned char *) *src;
      size_t dummy;

      temp_state = *data.__statep;
      data.__statep = &temp_state;

      result = 0;
      data.__outbufend = buf + sizeof (buf);

      do
	{
	  data.__outbuf = buf;

	  status = DL_CALL_FCT (fct, (tomb, &data, &inbuf,
				      (const unsigned char *) srcend, NULL,
				      &dummy, 0, 1));

	  /* Count the number of bytes.  */
	  result += data.__outbuf - buf;
	}
      while (status == __GCONV_FULL_OUTPUT);

      if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
	  && data.__outbuf[-1] == '\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.  */
      size_t dummy;

      data.__outbuf = (unsigned char *) dst;
      data.__outbufend = (unsigned char *) dst + len;

      status = DL_CALL_FCT (fct, (tomb, &data, (const unsigned char **) src,
				  (const unsigned char *) srcend, NULL,
				  &dummy, 0, 1));

      /* Count the number of bytes.  */
      result = data.__outbuf - (unsigned char *) dst;

      /* We have to determine whether the last character converted
	 is the NUL character.  */
      if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)
	  && data.__outbuf[-1] == '\0')
	{
	  assert (data.__outbuf != (unsigned char *) dst);
	  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)
    {
      result = (size_t) -1;
      __set_errno (EILSEQ);
    }

  return result;
}
weak_alias (__wcsnrtombs, wcsnrtombs)