gl/mbrtowc-impl-utf8.h


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

/* Convert multibyte character to wide character.
   Copyright (C) 1999-2002, 2005-2024 Free Software Foundation, Inc.

   This file 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.

   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>, 2008.  */

/* This file contains the part of the body of the mbrtowc and mbrtoc32 functions
   that handles the special case of the UTF-8 encoding.  */

        /* Cf. unistr/u8-mbtouc.c.  */
        unsigned char c = (unsigned char) p[0];

        if (c < 0x80)
          {
            if (pwc != NULL)
              *pwc = c;
            res = (c == 0 ? 0 : 1);
            goto success;
          }
        if (c >= 0xc2)
          {
            if (c < 0xe0)
              {
                if (m == 1)
                  goto incomplete;
                else /* m >= 2 */
                  {
                    unsigned char c2 = (unsigned char) p[1];

                    if ((c2 ^ 0x80) < 0x40)
                      {
                        if (pwc != NULL)
                          *pwc = ((unsigned int) (c & 0x1f) << 6)
                                 | (unsigned int) (c2 ^ 0x80);
                        res = 2;
                        goto success;
                      }
                  }
              }
            else if (c < 0xf0)
              {
                if (m == 1)
                  goto incomplete;
                else
                  {
                    unsigned char c2 = (unsigned char) p[1];

                    if ((c2 ^ 0x80) < 0x40
                        && (c >= 0xe1 || c2 >= 0xa0)
                        && (c != 0xed || c2 < 0xa0))
                      {
                        if (m == 2)
                          goto incomplete;
                        else /* m >= 3 */
                          {
                            unsigned char c3 = (unsigned char) p[2];

                            if ((c3 ^ 0x80) < 0x40)
                              {
                                unsigned int wc =
                                  (((unsigned int) (c & 0x0f) << 12)
                                   | ((unsigned int) (c2 ^ 0x80) << 6)
                                   | (unsigned int) (c3 ^ 0x80));

                                if (FITS_IN_CHAR_TYPE (wc))
                                  {
                                    if (pwc != NULL)
                                      *pwc = wc;
                                    res = 3;
                                    goto success;
                                  }
                              }
                          }
                      }
                  }
              }
            else if (c <= 0xf4)
              {
                if (m == 1)
                  goto incomplete;
                else
                  {
                    unsigned char c2 = (unsigned char) p[1];

                    if ((c2 ^ 0x80) < 0x40
                        && (c >= 0xf1 || c2 >= 0x90)
                        && (c < 0xf4 || (/* c == 0xf4 && */ c2 < 0x90)))
                      {
                        if (m == 2)
                          goto incomplete;
                        else
                          {
                            unsigned char c3 = (unsigned char) p[2];

                            if ((c3 ^ 0x80) < 0x40)
                              {
                                if (m == 3)
                                  goto incomplete;
                                else /* m >= 4 */
                                  {
                                    unsigned char c4 = (unsigned char) p[3];

                                    if ((c4 ^ 0x80) < 0x40)
                                      {
                                        unsigned int wc =
                                          (((unsigned int) (c & 0x07) << 18)
                                           | ((unsigned int) (c2 ^ 0x80) << 12)
                                           | ((unsigned int) (c3 ^ 0x80) << 6)
                                           | (unsigned int) (c4 ^ 0x80));

                                        if (FITS_IN_CHAR_TYPE (wc))
                                          {
                                            if (pwc != NULL)
                                              *pwc = wc;
                                            res = 4;
                                            goto success;
                                          }
                                      }
                                  }
                              }
                          }
                      }
                  }
              }
          }
        goto invalid;