ubuntu-buildroot/output/build/host-gcc-final-11.4.0/libsanitizer/sanitizer_common/sanitizer_libc.cpp

281 lines
7.2 KiB
C++

//===-- sanitizer_libc.cpp ------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries. See sanitizer_libc.h for details.
//===----------------------------------------------------------------------===//
#include "sanitizer_allocator_internal.h"
#include "sanitizer_common.h"
#include "sanitizer_libc.h"
namespace __sanitizer {
s64 internal_atoll(const char *nptr) {
return internal_simple_strtoll(nptr, nullptr, 10);
}
void *internal_memchr(const void *s, int c, uptr n) {
const char *t = (const char *)s;
for (uptr i = 0; i < n; ++i, ++t)
if (*t == c)
return reinterpret_cast<void *>(const_cast<char *>(t));
return nullptr;
}
void *internal_memrchr(const void *s, int c, uptr n) {
const char *t = (const char *)s;
void *res = nullptr;
for (uptr i = 0; i < n; ++i, ++t) {
if (*t == c) res = reinterpret_cast<void *>(const_cast<char *>(t));
}
return res;
}
int internal_memcmp(const void* s1, const void* s2, uptr n) {
const char *t1 = (const char *)s1;
const char *t2 = (const char *)s2;
for (uptr i = 0; i < n; ++i, ++t1, ++t2)
if (*t1 != *t2)
return *t1 < *t2 ? -1 : 1;
return 0;
}
void *internal_memcpy(void *dest, const void *src, uptr n) {
char *d = (char*)dest;
const char *s = (const char *)src;
for (uptr i = 0; i < n; ++i)
d[i] = s[i];
return dest;
}
void *internal_memmove(void *dest, const void *src, uptr n) {
char *d = (char*)dest;
const char *s = (const char *)src;
sptr i, signed_n = (sptr)n;
CHECK_GE(signed_n, 0);
if (d < s) {
for (i = 0; i < signed_n; ++i)
d[i] = s[i];
} else {
if (d > s && signed_n > 0) {
for (i = signed_n - 1; i >= 0; --i) {
d[i] = s[i];
}
}
}
return dest;
}
void *internal_memset(void* s, int c, uptr n) {
// Optimize for the most performance-critical case:
if ((reinterpret_cast<uptr>(s) % 16) == 0 && (n % 16) == 0) {
u64 *p = reinterpret_cast<u64*>(s);
u64 *e = p + n / 8;
u64 v = c;
v |= v << 8;
v |= v << 16;
v |= v << 32;
for (; p < e; p += 2)
p[0] = p[1] = v;
return s;
}
// The next line prevents Clang from making a call to memset() instead of the
// loop below.
// FIXME: building the runtime with -ffreestanding is a better idea. However
// there currently are linktime problems due to PR12396.
char volatile *t = (char*)s;
for (uptr i = 0; i < n; ++i, ++t) {
*t = c;
}
return s;
}
uptr internal_strcspn(const char *s, const char *reject) {
uptr i;
for (i = 0; s[i]; i++) {
if (internal_strchr(reject, s[i]))
return i;
}
return i;
}
char* internal_strdup(const char *s) {
uptr len = internal_strlen(s);
char *s2 = (char*)InternalAlloc(len + 1);
internal_memcpy(s2, s, len);
s2[len] = 0;
return s2;
}
int internal_strcmp(const char *s1, const char *s2) {
while (true) {
unsigned c1 = *s1;
unsigned c2 = *s2;
if (c1 != c2) return (c1 < c2) ? -1 : 1;
if (c1 == 0) break;
s1++;
s2++;
}
return 0;
}
int internal_strncmp(const char *s1, const char *s2, uptr n) {
for (uptr i = 0; i < n; i++) {
unsigned c1 = *s1;
unsigned c2 = *s2;
if (c1 != c2) return (c1 < c2) ? -1 : 1;
if (c1 == 0) break;
s1++;
s2++;
}
return 0;
}
char* internal_strchr(const char *s, int c) {
while (true) {
if (*s == (char)c)
return const_cast<char *>(s);
if (*s == 0)
return nullptr;
s++;
}
}
char *internal_strchrnul(const char *s, int c) {
char *res = internal_strchr(s, c);
if (!res)
res = const_cast<char *>(s) + internal_strlen(s);
return res;
}
char *internal_strrchr(const char *s, int c) {
const char *res = nullptr;
for (uptr i = 0; s[i]; i++) {
if (s[i] == c) res = s + i;
}
return const_cast<char *>(res);
}
uptr internal_strlen(const char *s) {
uptr i = 0;
while (s[i]) i++;
return i;
}
uptr internal_strlcat(char *dst, const char *src, uptr maxlen) {
const uptr srclen = internal_strlen(src);
const uptr dstlen = internal_strnlen(dst, maxlen);
if (dstlen == maxlen) return maxlen + srclen;
if (srclen < maxlen - dstlen) {
internal_memmove(dst + dstlen, src, srclen + 1);
} else {
internal_memmove(dst + dstlen, src, maxlen - dstlen - 1);
dst[maxlen - 1] = '\0';
}
return dstlen + srclen;
}
char *internal_strncat(char *dst, const char *src, uptr n) {
uptr len = internal_strlen(dst);
uptr i;
for (i = 0; i < n && src[i]; i++)
dst[len + i] = src[i];
dst[len + i] = 0;
return dst;
}
uptr internal_strlcpy(char *dst, const char *src, uptr maxlen) {
const uptr srclen = internal_strlen(src);
if (srclen < maxlen) {
internal_memmove(dst, src, srclen + 1);
} else if (maxlen != 0) {
internal_memmove(dst, src, maxlen - 1);
dst[maxlen - 1] = '\0';
}
return srclen;
}
char *internal_strncpy(char *dst, const char *src, uptr n) {
uptr i;
for (i = 0; i < n && src[i]; i++)
dst[i] = src[i];
internal_memset(dst + i, '\0', n - i);
return dst;
}
uptr internal_strnlen(const char *s, uptr maxlen) {
uptr i = 0;
while (i < maxlen && s[i]) i++;
return i;
}
char *internal_strstr(const char *haystack, const char *needle) {
// This is O(N^2), but we are not using it in hot places.
uptr len1 = internal_strlen(haystack);
uptr len2 = internal_strlen(needle);
if (len1 < len2) return nullptr;
for (uptr pos = 0; pos <= len1 - len2; pos++) {
if (internal_memcmp(haystack + pos, needle, len2) == 0)
return const_cast<char *>(haystack) + pos;
}
return nullptr;
}
s64 internal_simple_strtoll(const char *nptr, const char **endptr, int base) {
CHECK_EQ(base, 10);
while (IsSpace(*nptr)) nptr++;
int sgn = 1;
u64 res = 0;
bool have_digits = false;
char *old_nptr = const_cast<char *>(nptr);
if (*nptr == '+') {
sgn = 1;
nptr++;
} else if (*nptr == '-') {
sgn = -1;
nptr++;
}
while (IsDigit(*nptr)) {
res = (res <= UINT64_MAX / 10) ? res * 10 : UINT64_MAX;
int digit = ((*nptr) - '0');
res = (res <= UINT64_MAX - digit) ? res + digit : UINT64_MAX;
have_digits = true;
nptr++;
}
if (endptr) {
*endptr = (have_digits) ? const_cast<char *>(nptr) : old_nptr;
}
if (sgn > 0) {
return (s64)(Min((u64)INT64_MAX, res));
} else {
return (res > INT64_MAX) ? INT64_MIN : ((s64)res * -1);
}
}
bool mem_is_zero(const char *beg, uptr size) {
CHECK_LE(size, 1ULL << FIRST_32_SECOND_64(30, 40)); // Sanity check.
const char *end = beg + size;
uptr *aligned_beg = (uptr *)RoundUpTo((uptr)beg, sizeof(uptr));
uptr *aligned_end = (uptr *)RoundDownTo((uptr)end, sizeof(uptr));
uptr all = 0;
// Prologue.
for (const char *mem = beg; mem < (char*)aligned_beg && mem < end; mem++)
all |= *mem;
// Aligned loop.
for (; aligned_beg < aligned_end; aligned_beg++)
all |= *aligned_beg;
// Epilogue.
if ((char *)aligned_end >= beg) {
for (const char *mem = (char *)aligned_end; mem < end; mem++) all |= *mem;
}
return all == 0;
}
} // namespace __sanitizer