NetBSD/lib/libc/string/strpbrk.c

71 lines
2.4 KiB
C

/* $NetBSD: strpbrk.c,v 1.19 2008/09/24 16:58:53 christos Exp $ */
/*-
* Copyright (c) 2008 Joerg Sonnenberger
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: strpbrk.c,v 1.19 2008/09/24 16:58:53 christos Exp $");
#include <assert.h>
#include <inttypes.h>
#include <limits.h>
#include <string.h>
#define FAST_STRPBRK 1
#define UC(a) ((unsigned int)(unsigned char)(a))
#ifdef FAST_STRPBRK
#define ADD_NEW_TO_SET(i) (set[inv[i] = idx++] = (i))
#define IS_IN_SET(i) (inv[i] < idx && set[inv[i]] == (i))
#define ADD_TO_SET(i) (void)(IS_IN_SET(i) || /*LINTED no effect*/ADD_NEW_TO_SET(i))
#else
#define IS_IN_SET(i) (set[(i) >> 3] & idx[(i) & 7])
#define ADD_TO_SET(i) (void)(set[(i) >> 3] |= idx[(i) & 7])
#endif
char *
strpbrk(const char *s, const char *charset)
{
#ifdef FAST_STRPBRK
uint8_t set[256], inv[256], idx = 0;
#else
static const size_t idx[8] = { 1, 2, 4, 8, 16, 32, 64, 128 };
uint8_t set[32];
(void)memset(set, 0, sizeof(set));
#endif
_DIAGASSERT(s != NULL);
_DIAGASSERT(charset != NULL);
for (; *charset != '\0'; ++charset)
ADD_TO_SET(UC(*charset));
for (; *s != '\0'; ++s)
if (IS_IN_SET(UC(*s)))
return __UNCONST(s);
return NULL;
}