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unicode.h revision 1.4.12.1 
      1 /* $NetBSD: unicode.h,v 1.4.12.1 2007/02/27 16:54:11 yamt Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2001, 2004 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *        This product includes software developed by the NetBSD
     18  *        Foundation, Inc. and its contributors.
     19  * 4. Neither the name of The NetBSD Foundation nor the names of its
     20  *    contributors may be used to endorse or promote products derived
     21  *    from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     33  * POSSIBILITY OF SUCH DAMAGE.
     34  */
     35 
     36 /*-
     37  * Copyright (c) 1993
     38  *	The Regents of the University of California.  All rights reserved.
     39  *
     40  * This code is derived from software contributed to Berkeley by
     41  * Paul Borman at Krystal Technologies.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. All advertising materials mentioning features or use of this software
     52  *    must display the following acknowledgement:
     53  *	This product includes software developed by the University of
     54  *	California, Berkeley and its contributors.
     55  * 4. Neither the name of the University nor the names of its contributors
     56  *    may be used to endorse or promote products derived from this software
     57  *    without specific prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     69  * SUCH DAMAGE.
     70  */
     71 
     72 /*
     73  * Routines for handling Unicode encoded in UTF-8 form, code derived from
     74  * src/lib/libc/locale/utf2.c.
     75  */
     76 static u_int16_t wget_utf8(const char **, size_t *) __unused;
     77 static int wput_utf8(char *, size_t, u_int16_t) __unused;
     78 
     79 /*
     80  * Read one UTF8-encoded character off the string, shift the string pointer
     81  * and return the character.
     82  */
     83 static u_int16_t
     84 wget_utf8(const char **str, size_t *sz)
     85 {
     86 	int c;
     87 	u_int16_t rune = 0;
     88 	const char *s = *str;
     89 	static const int _utf_count[16] = {
     90 		1, 1, 1, 1, 1, 1, 1, 1,
     91 		0, 0, 0, 0, 2, 2, 3, 0,
     92 	};
     93 
     94 	/* must be called with at least one byte remaining */
     95 	KASSERT(*sz > 0);
     96 
     97 	c = _utf_count[(s[0] & 0xf0) >> 4];
     98 	if (c == 0 || c > *sz) {
     99     decoding_error:
    100 		/*
    101 		 * The first character is in range 128-255 and doesn't
    102 		 * mark valid a valid UTF-8 sequence. There is not much
    103 		 * we can do with this, so handle by returning
    104 		 * the first character as if it would be a correctly
    105 		 * encoded ISO-8859-1 character.
    106 		 */
    107 		c = 1;
    108 	}
    109 
    110 	switch (c) {
    111 	case 1:
    112 		rune = s[0] & 0xff;
    113 		break;
    114 	case 2:
    115 		if ((s[1] & 0xc0) != 0x80)
    116 			goto decoding_error;
    117 		rune = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F);
    118 		break;
    119 	case 3:
    120 		if ((s[1] & 0xC0) != 0x80 || (s[2] & 0xC0) != 0x80)
    121 			goto decoding_error;
    122 		rune = ((s[0] & 0x0F) << 12) | ((s[1] & 0x3F) << 6)
    123 		    | (s[2] & 0x3F);
    124 		break;
    125 	}
    126 
    127 	*str += c;
    128 	*sz -= c;
    129 	return rune;
    130 }
    131 
    132 /*
    133  * Encode wide character and write it to the string. 'n' specifies
    134  * how much buffer space remains in 's'. Returns number of bytes written
    135  * to the target string 's'.
    136  */
    137 static int
    138 wput_utf8(char *s, size_t n, u_int16_t wc)
    139 {
    140 	if (wc & 0xf800) {
    141 		if (n < 3) {
    142 			/* bound check failure */
    143 			return 0;
    144 		}
    145 
    146 		s[0] = 0xE0 | (wc >> 12);
    147 		s[1] = 0x80 | ((wc >> 6) & 0x3F);
    148 		s[2] = 0x80 | ((wc) & 0x3F);
    149 		return 3;
    150 	} else if (wc & 0x0780) {
    151 		if (n < 2) {
    152 			/* bound check failure */
    153 			return 0;
    154 		}
    155 
    156 		s[0] = 0xC0 | (wc >> 6);
    157 		s[1] = 0x80 | ((wc) & 0x3F);
    158 		return 2;
    159 	} else {
    160 		if (n < 1) {
    161 			/* bound check failure */
    162 			return 0;
    163 		}
    164 
    165 		s[0] = wc;
    166 		return 1;
    167 	}
    168 }
    169