1 /*
2  * Copyright (c) 2009-2021, Google LLC
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *     * Redistributions of source code must retain the above copyright
8  *       notice, this list of conditions and the following disclaimer.
9  *     * Redistributions in binary form must reproduce the above copyright
10  *       notice, this list of conditions and the following disclaimer in the
11  *       documentation and/or other materials provided with the distribution.
12  *     * Neither the name of Google LLC nor the
13  *       names of its contributors may be used to endorse or promote products
14  *       derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL Google LLC BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "upb/lex/unicode.h"
29 
30 // Must be last.
31 #include "upb/port/def.inc"
32 
upb_Unicode_ToUTF8(uint32_t cp,char * out)33 int upb_Unicode_ToUTF8(uint32_t cp, char* out) {
34   if (cp <= 0x7f) {
35     out[0] = cp;
36     return 1;
37   }
38   if (cp <= 0x07ff) {
39     out[0] = (cp >> 6) | 0xc0;
40     out[1] = (cp & 0x3f) | 0x80;
41     return 2;
42   }
43   if (cp <= 0xffff) {
44     out[0] = (cp >> 12) | 0xe0;
45     out[1] = ((cp >> 6) & 0x3f) | 0x80;
46     out[2] = (cp & 0x3f) | 0x80;
47     return 3;
48   }
49   if (cp <= 0x10ffff) {
50     out[0] = (cp >> 18) | 0xf0;
51     out[1] = ((cp >> 12) & 0x3f) | 0x80;
52     out[2] = ((cp >> 6) & 0x3f) | 0x80;
53     out[3] = (cp & 0x3f) | 0x80;
54     return 4;
55   }
56   return 0;
57 }
58