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#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <signal.h>
#include <assert.h>
extern "C" {
void bzero(void* dest, size_t n)
{
memset(dest, 0, n);
}
void bcopy(const void* src, void* dest, size_t n)
{
memmove(dest, src, n);
}
void* memset(void* dest, int c, size_t n)
{
uint8_t* bdest = (uint8_t*)dest;
for (; n; --n)
*(bdest++) = c;
return dest;
}
size_t strspn(const char* s, const char* accept)
{
const char* p = s;
cont:
char ch = *p++;
char ac;
for (const char* ap = accept; (ac = *ap++) != '\0';) {
if (ac == ch)
goto cont;
}
return p - 1 - s;
}
size_t strcspn(const char* s, const char* reject)
{
for (auto* p = s;;) {
char c = *p++;
auto* rp = reject;
char rc;
do {
if ((rc = *rp++) == c)
return p - 1 - s;
} while(rc);
}
}
size_t strlen(const char* str)
{
size_t len = 0;
while (*(str++))
++len;
return len;
}
int strcmp(const char* s1, const char* s2)
{
while (*s1 == *s2++)
if (*s1++ == 0)
return 0;
return *(const unsigned char*)s1 - *(const unsigned char*)--s2;
}
int strncmp(const char* s1, const char* s2, size_t n)
{
if (!n)
return 0;
do {
if (*s1 != *s2++)
return *(const unsigned char*)s1 - *(const unsigned char*)--s2;
if (*s1++ == 0)
break;
} while (--n);
return 0;
}
int memcmp(const void* v1, const void* v2, size_t n)
{
auto* s1 = (const uint8_t*)v1;
auto* s2 = (const uint8_t*)v2;
while (n-- > 0) {
if (*s1++ != *s2++)
return s1[-1] < s2[-1] ? -1 : 1;
}
return 0;
}
void* memcpy(void* dest, const void* src, size_t n)
{
auto* bdest = (unsigned char*)dest;
auto* bsrc = (const unsigned char*)src;
for (; n; --n)
*(bdest++) = *(bsrc++);
return dest;
}
void* memmove(void* dest, const void* src, size_t n)
{
if (dest < src)
return memcpy(dest, src, n);
// FIXME: Implement backwards copy.
assert(false);
}
char* strcpy(char* dest, const char *src)
{
char* originalDest = dest;
while ((*dest++ = *src++) != '\0');
return originalDest;
}
char* strncpy(char* dest, const char* src, size_t n)
{
size_t i;
for (i = 0; i < n && src[i] != '\0'; ++i)
dest[i] = src[i];
for ( ; i < n; ++i)
dest[i] = '\0';
return dest;
}
char* strchr(const char* str, int c)
{
char ch = c;
for (;; ++str) {
if (*str == ch)
return const_cast<char*>(str);
if (!*str)
return nullptr;
}
}
char* strrchr(const char* str, int ch)
{
char *last = nullptr;
char c;
for (; (c = *str); ++str) {
if (c == ch)
last = const_cast<char*>(str);
}
return last;
}
char* strcat(char *dest, const char *src)
{
size_t destLength = strlen(dest);
size_t i;
for (i = 0 ; src[i] != '\0' ; i++)
dest[destLength + i] = src[i];
dest[destLength + i] = '\0';
return dest;
}
char* strncat(char *dest, const char *src, size_t n)
{
size_t destLength = strlen(dest);
size_t i;
for (i = 0 ; i < n && src[i] != '\0' ; i++)
dest[destLength + i] = src[i];
dest[destLength + i] = '\0';
return dest;
}
const char* sys_errlist[] = {
#undef __ERROR
#define __ERROR(a, b) b,
__ENUMERATE_ALL_ERRORS
#undef __ERROR
};
int sys_nerr = __errno_count;
char* strerror(int errnum)
{
if (errnum >= __errno_count) {
printf("strerror() missing string for errnum=%d\n", errnum);
return const_cast<char*>("Unknown error");
}
return const_cast<char*>(sys_errlist[errnum]);
}
char* strsignal(int signum)
{
if (signum >= __signal_count) {
printf("strsignal() missing string for signum=%d\n", signum);
return const_cast<char*>("Unknown signal");
}
return const_cast<char*>(sys_siglist[signum]);
}
char* strstr(const char* haystack, const char* needle)
{
char nch;
char hch;
if ((nch = *needle++) != 0) {
size_t len = strlen(needle);
do {
do {
if ((hch = *haystack++) == 0)
return nullptr;
} while (hch != nch);
} while (strncmp(haystack, needle, len) != 0);
--haystack;
}
return const_cast<char*>(haystack);
}
}
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