Source code
Revision control
Copy as Markdown
Other Tools
// Copyright (c) 2012, Google 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:
//
// * 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.
// * Neither the name of Google Inc. 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
// 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.
// This source file provides replacements for libc functions that we need. If
// we call the libc functions directly we risk crashing in the dynamic linker
// as it tries to resolve uncached PLT entries.
#include "common/linux/linux_libc_support.h"
#include <stddef.h>
extern "C" {
size_t my_strlen(const char* s) {
size_t len = 0;
while (*s++) len++;
return len;
}
int my_strcmp(const char* a, const char* b) {
for (;;) {
if (*a < *b)
return -1;
else if (*a > *b)
return 1;
else if (*a == 0)
return 0;
a++;
b++;
}
}
int my_strncmp(const char* a, const char* b, size_t len) {
for (size_t i = 0; i < len; ++i) {
if (*a < *b)
return -1;
else if (*a > *b)
return 1;
else if (*a == 0)
return 0;
a++;
b++;
}
return 0;
}
// Parse a non-negative integer.
// result: (output) the resulting non-negative integer
// s: a NUL terminated string
// Return true iff successful.
bool my_strtoui(int* result, const char* s) {
if (*s == 0)
return false;
int r = 0;
for (;; s++) {
if (*s == 0)
break;
const int old_r = r;
r *= 10;
if (*s < '0' || *s > '9')
return false;
r += *s - '0';
if (r < old_r)
return false;
}
*result = r;
return true;
}
// Return the length of the given unsigned integer when expressed in base 10.
unsigned my_uint_len(uintmax_t i) {
if (!i)
return 1;
int len = 0;
while (i) {
len++;
i /= 10;
}
return len;
}
// Convert an unsigned integer to a string
// output: (output) the resulting string is written here. This buffer must be
// large enough to hold the resulting string. Call |my_uint_len| to get the
// required length.
// i: the unsigned integer to serialise.
// i_len: the length of the integer in base 10 (see |my_uint_len|).
void my_uitos(char* output, uintmax_t i, unsigned i_len) {
for (unsigned index = i_len; index; --index, i /= 10)
output[index - 1] = '0' + (i % 10);
}
const char* my_strchr(const char* haystack, char needle) {
while (*haystack && *haystack != needle)
haystack++;
if (*haystack == needle)
return haystack;
return (const char*) 0;
}
const char* my_strrchr(const char* haystack, char needle) {
const char* ret = NULL;
while (*haystack) {
if (*haystack == needle)
ret = haystack;
haystack++;
}
return ret;
}
const char* my_strstr(const char* haystack, const char* needle) {
while (*haystack != 0) {
if((*haystack == *needle) &&
(my_strncmp(haystack, needle, my_strlen(needle)) == 0)) {
return haystack;
}
haystack++;
}
return nullptr;
}
void* my_memchr(const void* src, int needle, size_t src_len) {
const unsigned char* p = (const unsigned char*)src;
const unsigned char* p_end = p + src_len;
for (; p < p_end; ++p) {
if (*p == needle)
return (void*)p;
}
return NULL;
}
// Read a hex value
// result: (output) the resulting value
// s: a string
// Returns a pointer to the first invalid charactor.
const char* my_read_hex_ptr(uintptr_t* result, const char* s) {
uintptr_t r = 0;
for (;; ++s) {
if (*s >= '0' && *s <= '9') {
r <<= 4;
r += *s - '0';
} else if (*s >= 'a' && *s <= 'f') {
r <<= 4;
r += (*s - 'a') + 10;
} else if (*s >= 'A' && *s <= 'F') {
r <<= 4;
r += (*s - 'A') + 10;
} else {
break;
}
}
*result = r;
return s;
}
const char* my_read_decimal_ptr(uintptr_t* result, const char* s) {
uintptr_t r = 0;
for (;; ++s) {
if (*s >= '0' && *s <= '9') {
r *= 10;
r += *s - '0';
} else {
break;
}
}
*result = r;
return s;
}
void my_memset(void* ip, char c, size_t len) {
char* p = (char *) ip;
while (len--)
*p++ = c;
}
size_t my_strlcpy(char* s1, const char* s2, size_t len) {
size_t pos1 = 0;
size_t pos2 = 0;
while (s2[pos2] != '\0') {
if (pos1 + 1 < len) {
s1[pos1] = s2[pos2];
pos1++;
}
pos2++;
}
if (len > 0)
s1[pos1] = '\0';
return pos2;
}
size_t my_strlcat(char* s1, const char* s2, size_t len) {
size_t pos1 = 0;
while (pos1 < len && s1[pos1] != '\0')
pos1++;
if (pos1 == len)
return pos1;
return pos1 + my_strlcpy(s1 + pos1, s2, len - pos1);
}
int my_isspace(int ch) {
// Matches the C locale.
const char spaces[] = " \t\f\n\r\t\v";
for (size_t i = 0; i < sizeof(spaces); i++) {
if (ch == spaces[i])
return 1;
}
return 0;
}
} // extern "C"