projects / apple / libc.git / blame
| Commit | Line | Data |
|---|---|---|
| 224c7076 A |
1 | /*- |
| 2 | * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG> | |
| 3 | * All rights reserved. | |
| e9ce8d39 A |
4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without | |
| 6 | * modification, are permitted provided that the following conditions | |
| 7 | * are met: | |
| 8 | * 1. Redistributions of source code must retain the above copyright | |
| 9 | * notice, this list of conditions and the following disclaimer. | |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 | * notice, this list of conditions and the following disclaimer in the | |
| 12 | * documentation and/or other materials provided with the distribution. | |
| e9ce8d39 | 13 | * |
| 224c7076 | 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| e9ce8d39 A |
15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 224c7076 | 17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| e9ce8d39 A |
18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 24 | * SUCH DAMAGE. | |
| 25 | */ | |
| 26 | ||
| 9385eb3d | 27 | #include <sys/cdefs.h> |
| 224c7076 | 28 | __FBSDID("$FreeBSD: src/lib/libc/string/strspn.c,v 1.5 2005/04/02 18:52:44 das Exp $"); |
| e9ce8d39 | 29 | |
| 224c7076 A |
30 | #include <sys/types.h> |
| 31 | #include <limits.h> | |
| 9385eb3d | 32 | #include <string.h> |
| e9ce8d39 | 33 | |
| 224c7076 A |
34 | #define IDX(c) ((u_char)(c) / LONG_BIT) |
| 35 | #define BIT(c) ((u_long)1 << ((u_char)(c) % LONG_BIT)) | |
| 36 | ||
| 9385eb3d | 37 | size_t |
| 224c7076 | 38 | strspn(const char *s, const char *charset) |
| e9ce8d39 | 39 | { |
| 9385eb3d | 40 | /* |
| 224c7076 A |
41 | * NB: idx and bit are temporaries whose use causes gcc 3.4.2 to |
| 42 | * generate better code. Without them, gcc gets a little confused. | |
| 9385eb3d | 43 | */ |
| 224c7076 A |
44 | const char *s1; |
| 45 | u_long bit; | |
| 46 | u_long tbl[(UCHAR_MAX + 1) / LONG_BIT]; | |
| 47 | int idx; | |
| 48 | ||
| 49 | if(*s == '\0') | |
| 50 | return (0); | |
| 51 | ||
| 52 | #if LONG_BIT == 64 /* always better to unroll on 64-bit architectures */ | |
| 53 | tbl[3] = tbl[2] = tbl[1] = tbl[0] = 0; | |
| 54 | #else | |
| 55 | for (idx = 0; idx < sizeof(tbl) / sizeof(tbl[0]); idx++) | |
| 56 | tbl[idx] = 0; | |
| 57 | #endif | |
| 58 | for (; *charset != '\0'; charset++) { | |
| 59 | idx = IDX(*charset); | |
| 60 | bit = BIT(*charset); | |
| 61 | tbl[idx] |= bit; | |
| 62 | } | |
| 63 | ||
| 64 | for(s1 = s; ; s1++) { | |
| 65 | idx = IDX(*s1); | |
| 66 | bit = BIT(*s1); | |
| 67 | if ((tbl[idx] & bit) == 0) | |
| 68 | break; | |
| 69 | } | |
| 70 | return (s1 - s); | |
| e9ce8d39 | 71 | } |