bionic/libc/bionic/memrchr.c
Elliott Hughes a89864a20b Move non-upstream code into the libc/bionic directory.
I'll need at least one more pass, because there's some upstream code
lurking in libc/bionic, but this is still a step in the right direction.

Change-Id: I55927315972da8327ae01c5240ed587db17e8462
2012-10-01 17:35:49 -07:00

48 lines
1.9 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 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 OWNER 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.
*/
#include <stddef.h>
#include <string.h>
void *memrchr(const void *s, int c, size_t n)
{
if (n > 0) {
const char* p = (const char*) s;
const char* q = p + n;
while (1) {
q--; if (q < p || q[0] == (char) c) break;
q--; if (q < p || q[0] == (char) c) break;
q--; if (q < p || q[0] == (char) c) break;
q--; if (q < p || q[0] == (char) c) break;
}
if (q >= p)
return (void*)q;
}
return NULL;
}