ncurses 6.2 - patch 20200711
[ncurses.git] / ncurses / widechar / widechars.c
1 /****************************************************************************
2  * Copyright 2018,2020 Thomas E. Dickey                                     *
3  * Copyright 2012,2013 Free Software Foundation, Inc.                       *
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11  * furnished to do so, subject to the following conditions:                 *
12  *                                                                          *
13  * The above copyright notice and this permission notice shall be included  *
14  * in all copies or substantial portions of the Software.                   *
15  *                                                                          *
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18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
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25  * holders shall not be used in advertising or otherwise to promote the     *
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28  ****************************************************************************/
29
30 #include <curses.priv.h>
31
32 #if USE_WIDEC_SUPPORT
33
34 MODULE_ID("$Id: widechars.c,v 1.8 2020/07/11 20:48:42 anonymous.maarten Exp $")
35
36 #if defined(_WIN32) && !defined(_MSC_VER)
37 /*
38  * MinGW has wide-character functions, but they do not work correctly.
39  */
40
41 int
42 _nc_mbtowc(wchar_t *pwc, const char *s, size_t n)
43 {
44     int result;
45     int count;
46     int try;
47
48     if (s != 0 && n != 0) {
49         /*
50          * MultiByteToWideChar() can decide to return more than one
51          * wide-character.  We want only one.  Ignore any trailing null, both
52          * in the initial count and in the conversion.
53          */
54         count = 0;
55         for (try = 1; try <= (int) n; ++try) {
56             count = MultiByteToWideChar(CP_UTF8,
57                                         MB_ERR_INVALID_CHARS,
58                                         s,
59                                         try,
60                                         pwc,
61                                         0);
62             TR(TRACE_BITS, ("...try %d:%d", try, count));
63             if (count > 0) {
64                 break;
65             }
66         }
67         if (count < 1 || count > 2) {
68             result = -1;
69         } else {
70             wchar_t actual[2];
71             memset(&actual, 0, sizeof(actual));
72             count = MultiByteToWideChar(CP_UTF8,
73                                         MB_ERR_INVALID_CHARS,
74                                         s,
75                                         try,
76                                         actual,
77                                         2);
78             TR(TRACE_BITS, ("\twin32 ->%#x, %#x", actual[0], actual[1]));
79             *pwc = actual[0];
80             if (actual[1] != 0)
81                 result = -1;
82             else
83                 result = try;
84         }
85     } else {
86         result = 0;
87     }
88
89     return result;
90 }
91
92 int
93 _nc_mblen(const char *s, size_t n)
94 {
95     int result = -1;
96     int count;
97     wchar_t temp;
98
99     if (s != 0 && n != 0) {
100         count = _nc_mbtowc(&temp, s, n);
101         if (count == 1) {
102             int check = WideCharToMultiByte(CP_UTF8,
103                                             0,
104                                             &temp,
105                                             1,
106                                             NULL,
107                                             0,  /* compute length only */
108                                             NULL,
109                                             NULL);
110             TR(TRACE_BITS, ("\tcheck ->%d\n", check));
111             if (check > 0 && (size_t) check <= n) {
112                 result = check;
113             }
114         }
115     } else {
116         result = 0;
117     }
118
119     return result;
120 }
121
122 int __MINGW_NOTHROW
123 _nc_wctomb(char *s, wchar_t wc)
124 {
125     int result;
126     int check;
127
128     check = WideCharToMultiByte(CP_UTF8,
129                                 0,
130                                 &wc,
131                                 1,
132                                 NULL,
133                                 0,      /* compute length only */
134                                 NULL,
135                                 NULL);
136     if (check > 0) {
137         result = WideCharToMultiByte(CP_UTF8,
138                                      0,
139                                      &wc,
140                                      1,
141                                      s,
142                                      check + 1,
143                                      NULL,
144                                      NULL);
145     } else {
146         result = -1;
147     }
148     return result;
149 }
150
151 #endif /* _WIN32 */
152
153 #endif /* USE_WIDEC_SUPPORT */