| // SPDX-License-Identifier: BSD-3-Clause |
| /* |
| * Copyright (c) 1994-2009 Red Hat, Inc. |
| * 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. |
| * |
| * 3. Neither the name of the copyright holder nor the names of its |
| * contributors may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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. |
| */ |
| |
| /* This file is copied from newlib-1.19 */ |
| |
| /* |
| FUNCTION |
| <<strcmp>>---character string compare |
| |
| INDEX |
| strcmp |
| |
| ANSI_SYNOPSIS |
| #include <string.h> |
| int strcmp(const char *<[a]>, const char *<[b]>); |
| |
| TRAD_SYNOPSIS |
| #include <string.h> |
| int strcmp(<[a]>, <[b]>) |
| char *<[a]>; |
| char *<[b]>; |
| |
| DESCRIPTION |
| <<strcmp>> compares the string at <[a]> to |
| the string at <[b]>. |
| |
| RETURNS |
| If <<*<[a]>>> sorts lexicographically after <<*<[b]>>>, |
| <<strcmp>> returns a number greater than zero. If the two |
| strings match, <<strcmp>> returns zero. If <<*<[a]>>> |
| sorts lexicographically before <<*<[b]>>>, <<strcmp>> returns a |
| number less than zero. |
| |
| PORTABILITY |
| <<strcmp>> is ANSI C. |
| |
| <<strcmp>> requires no supporting OS subroutines. |
| |
| QUICKREF |
| strcmp ansi pure |
| */ |
| |
| #include "_ansi.h" |
| #include <string.h> |
| #include <limits.h> |
| |
| /* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
| #define UNALIGNED(X, Y) \ |
| (((long)X & (sizeof(long) - 1)) | ((long)Y & (sizeof(long) - 1))) |
| |
| /* DETECTNULL returns nonzero if (long)X contains a NULL byte. */ |
| #if LONG_MAX == 2147483647L |
| #define DETECTNULL(X) (((X) - 0x01010101L) & ~(X) & 0x80808080UL) |
| #else |
| #if LONG_MAX == 9223372036854775807L |
| #define DETECTNULL(X) (((X) - 0x0101010101010101L) & ~(X) & \ |
| 0x8080808080808080UL) |
| #else |
| #error long int is not a 32bit or 64bit type. |
| #endif |
| #endif |
| |
| #ifndef DETECTNULL |
| #error long int is not a 32bit or 64bit byte |
| #endif |
| |
| int _DEFUN(strcmp, (s1, s2), _CONST char *s1 _AND _CONST char *s2) |
| { |
| #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
| while (*s1 != '\0' && *s1 == *s2) { |
| s1++; |
| s2++; |
| } |
| |
| return (*(unsigned char *)s1) - (*(unsigned char *)s2); |
| #else |
| unsigned long *a1; |
| unsigned long *a2; |
| |
| /* If s1 or s2 are unaligned, then compare bytes. */ |
| if (!UNALIGNED(s1, s2)) { |
| /* |
| * If s1 and s2 are word-aligned, compare them a word at a time. |
| */ |
| a1 = (unsigned long *)s1; |
| a2 = (unsigned long *)s2; |
| while (*a1 == *a2) { |
| /* |
| * To get here, *a1 == *a2, thus if we find a null in |
| * *a1, then the strings must be equal, so return zero. |
| */ |
| if (DETECTNULL(*a1)) |
| return 0; |
| |
| a1++; |
| a2++; |
| } |
| |
| /* |
| * A difference was detected in last few bytes of s1, so search |
| * bytewise. |
| */ |
| s1 = (char *)a1; |
| s2 = (char *)a2; |
| } |
| |
| while (*s1 != '\0' && *s1 == *s2) { |
| s1++; |
| s2++; |
| } |
| return (*(unsigned char *)s1) - (*(unsigned char *)s2); |
| #endif /* not PREFER_SIZE_OVER_SPEED */ |
| } |