Make more functions friendly to Address Sanitizer

This commit is contained in:
Justine Tunney 2021-02-02 03:45:31 -08:00
parent 3ab76b2312
commit cbfd4ccd1e
70 changed files with 1267 additions and 291 deletions

69
libc/str/strchrnul.c Normal file
View file

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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2021 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/assert.h"
#include "libc/str/str.h"
noasan static const unsigned char *strchrnul$x64(const unsigned char *p,
uint64_t c) {
unsigned a, b;
uint64_t w, x, y;
for (c *= 0x0101010101010101;; p += 8) {
w = (uint64_t)p[7] << 070 | (uint64_t)p[6] << 060 | (uint64_t)p[5] << 050 |
(uint64_t)p[4] << 040 | (uint64_t)p[3] << 030 | (uint64_t)p[2] << 020 |
(uint64_t)p[1] << 010 | (uint64_t)p[0] << 000;
if ((x = ~(w ^ c) & ((w ^ c) - 0x0101010101010101) & 0x8080808080808080) |
(y = ~w & (w - 0x0101010101010101) & 0x8080808080808080)) {
if (x) {
a = __builtin_ctzll(x);
if (y) {
b = __builtin_ctzll(y);
if (a <= b) {
return p + (a >> 3);
} else {
return p + (b >> 3);
}
} else {
return p + (a >> 3);
}
} else {
b = __builtin_ctzll(y);
return p + (b >> 3);
}
}
}
}
/**
* Returns pointer to first instance of character.
*
* @param s is a NUL-terminated string
* @param c is masked with 255 as byte to search for
* @return pointer to first instance of c, or pointer to
* NUL terminator if c is not found
*/
char *strchrnul(const char *s, int c) {
char *r;
for (c &= 0xff; (uintptr_t)s & 7; ++s) {
if ((*s & 0xff) == c) return s;
if (!*s) return s;
}
r = (char *)strchrnul$x64((const unsigned char *)s, c);
assert((*r & 0xff) == c || !*r);
return r;
}