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      1 /*	$NetBSD: strpbrk.c,v 1.3 2024/01/20 14:55:11 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2008 Joerg Sonnenberger
      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  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __RCSID("$NetBSD: strpbrk.c,v 1.3 2024/01/20 14:55:11 christos Exp $");
     30 
     31 #if !defined(_KERNEL) && !defined(_STANDALONE)
     32 #include <assert.h>
     33 #include <inttypes.h>
     34 #include <limits.h>
     35 #include <string.h>
     36 #else
     37 #include <lib/libkern/libkern.h>
     38 #endif
     39 
     40 #define FAST_STRPBRK 1
     41 #define UC(a) ((unsigned int)(unsigned char)(a))
     42 
     43 #ifdef FAST_STRPBRK
     44 #define ADD_NEW_TO_SET(i) (set[inv[i] = idx++] = (i))
     45 #define IS_IN_SET(i) (inv[i] < idx && set[inv[i]] == (i))
     46 #define ADD_TO_SET(i) (void)(IS_IN_SET(i) || /*LINTED no effect*/ADD_NEW_TO_SET(i))
     47 #else
     48 #define IS_IN_SET(i) (set[(i) >> 3] & idx[(i) & 7])
     49 #define ADD_TO_SET(i) (void)(set[(i) >> 3] |= idx[(i) & 7])
     50 #endif
     51 
     52 char *
     53 strpbrk(const char *s, const char *charset)
     54 {
     55 #ifdef FAST_STRPBRK
     56 	uint8_t set[256], inv[256], idx = 0;
     57 #else
     58 	static const size_t idx[8] = { 1, 2, 4, 8, 16, 32, 64, 128 };
     59 	uint8_t set[32];
     60 
     61 	(void)memset(set, 0, sizeof(set));
     62 #endif
     63 
     64 	if (charset[0] == '\0')
     65 		return NULL;
     66 	if (charset[1] == '\0')
     67 		return __UNCONST(strchr(s, charset[0]));
     68 
     69 	for (; *charset != '\0'; ++charset)
     70 		ADD_TO_SET(UC(*charset));
     71 
     72 	for (; *s != '\0'; ++s)
     73 		if (IS_IN_SET(UC(*s)))
     74 			return __UNCONST(s);
     75 	return NULL;
     76 }
     77