summaryrefslogtreecommitdiff
path: root/lib/iconv_open.c
blob: d5c5a52a3ea5fed31cdb0937b01a4f37ac989065 (plain)
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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/* Character set conversion.
   Copyright (C) 2007, 2009-2016 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   This program 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 General Public License for more details.

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

#include <config.h>

/* Specification.  */
#include <iconv.h>

#include <errno.h>
#include <string.h>
#include "c-ctype.h"
#include "c-strcase.h"

#define SIZEOF(a) (sizeof(a) / sizeof(a[0]))

/* Namespace cleanliness.  */
#define mapping_lookup rpl_iconv_open_mapping_lookup

/* The macro ICONV_FLAVOR is defined to one of these or undefined.  */

#define ICONV_FLAVOR_AIX "iconv_open-aix.h"
#define ICONV_FLAVOR_HPUX "iconv_open-hpux.h"
#define ICONV_FLAVOR_IRIX "iconv_open-irix.h"
#define ICONV_FLAVOR_OSF "iconv_open-osf.h"
#define ICONV_FLAVOR_SOLARIS "iconv_open-solaris.h"

#ifdef ICONV_FLAVOR
# include ICONV_FLAVOR
#endif

iconv_t
rpl_iconv_open (const char *tocode, const char *fromcode)
#undef iconv_open
{
  char fromcode_upper[32];
  char tocode_upper[32];
  char *fromcode_upper_end;
  char *tocode_upper_end;

#if REPLACE_ICONV_UTF
  /* Special handling of conversion between UTF-8 and UTF-{16,32}{BE,LE}.
     Do this here, before calling the real iconv_open(), because  OSF/1 5.1
     iconv() to these encoding inserts a BOM, which is wrong.
     We do not need to handle conversion between arbitrary encodings and
     UTF-{16,32}{BE,LE}, because the 'striconveh' module implements two-step
     conversion through UTF-8.
     The _ICONV_* constants are chosen to be disjoint from any iconv_t
     returned by the system's iconv_open() functions.  Recall that iconv_t
     is a scalar type.  */
  if (c_toupper (fromcode[0]) == 'U'
      && c_toupper (fromcode[1]) == 'T'
      && c_toupper (fromcode[2]) == 'F'
      && fromcode[3] == '-')
    {
      if (c_toupper (tocode[0]) == 'U'
          && c_toupper (tocode[1]) == 'T'
          && c_toupper (tocode[2]) == 'F'
          && tocode[3] == '-')
        {
          if (strcmp (fromcode + 4, "8") == 0)
            {
              if (c_strcasecmp (tocode + 4, "16BE") == 0)
                return _ICONV_UTF8_UTF16BE;
              if (c_strcasecmp (tocode + 4, "16LE") == 0)
                return _ICONV_UTF8_UTF16LE;
              if (c_strcasecmp (tocode + 4, "32BE") == 0)
                return _ICONV_UTF8_UTF32BE;
              if (c_strcasecmp (tocode + 4, "32LE") == 0)
                return _ICONV_UTF8_UTF32LE;
            }
          else if (strcmp (tocode + 4, "8") == 0)
            {
              if (c_strcasecmp (fromcode + 4, "16BE") == 0)
                return _ICONV_UTF16BE_UTF8;
              if (c_strcasecmp (fromcode + 4, "16LE") == 0)
                return _ICONV_UTF16LE_UTF8;
              if (c_strcasecmp (fromcode + 4, "32BE") == 0)
                return _ICONV_UTF32BE_UTF8;
              if (c_strcasecmp (fromcode + 4, "32LE") == 0)
                return _ICONV_UTF32LE_UTF8;
            }
        }
    }
#endif

  /* Do *not* add special support for 8-bit encodings like ASCII or ISO-8859-1
     here.  This would lead to programs that work in some locales (such as the
     "C" or "en_US" locales) but do not work in East Asian locales.  It is
     better if programmers make their programs depend on GNU libiconv (except
     on glibc systems), e.g. by using the AM_ICONV macro and documenting the
     dependency in an INSTALL or DEPENDENCIES file.  */

  /* Try with the original names first.
     This covers the case when fromcode or tocode is a lowercase encoding name
     that is understood by the system's iconv_open but not listed in our
     mappings table.  */
  {
    iconv_t cd = iconv_open (tocode, fromcode);
    if (cd != (iconv_t)(-1))
      return cd;
  }

  /* Convert the encodings to upper case, because
       1. in the arguments of iconv_open() on AIX, HP-UX, and OSF/1 the case
          matters,
       2. it makes searching in the table faster.  */
  {
    const char *p = fromcode;
    char *q = fromcode_upper;
    while ((*q = c_toupper (*p)) != '\0')
      {
        p++;
        q++;
        if (q == &fromcode_upper[SIZEOF (fromcode_upper)])
          {
            errno = EINVAL;
            return (iconv_t)(-1);
          }
      }
    fromcode_upper_end = q;
  }

  {
    const char *p = tocode;
    char *q = tocode_upper;
    while ((*q = c_toupper (*p)) != '\0')
      {
        p++;
        q++;
        if (q == &tocode_upper[SIZEOF (tocode_upper)])
          {
            errno = EINVAL;
            return (iconv_t)(-1);
          }
      }
    tocode_upper_end = q;
  }

#ifdef ICONV_FLAVOR
  /* Apply the mappings.  */
  {
    const struct mapping *m =
      mapping_lookup (fromcode_upper, fromcode_upper_end - fromcode_upper);

    fromcode = (m != NULL ? m->vendor_name : fromcode_upper);
  }
  {
    const struct mapping *m =
      mapping_lookup (tocode_upper, tocode_upper_end - tocode_upper);

    tocode = (m != NULL ? m->vendor_name : tocode_upper);
  }
#else
  fromcode = fromcode_upper;
  tocode = tocode_upper;
#endif

  return iconv_open (tocode, fromcode);
}