HarmonyOS NDK编译错误

static const char *get_top_domain(const char * const domain, size_t *outlen) 
{ 
  size_t len; 
  const char *first = NULL, *last; 
  if(!domain) 
    return NULL; 
  len = strlen(domain); 
  last = memrchr(domain, '.', len); 
  if(last) { 
    first = memrchr(domain, '.', (last - domain)); 
    if(first) 
      len -= (++first - domain); 
  } 
  if(outlen) 
  *outlen = len; 
  return first? first: domain; 
}

cookie.c:253:10: warning: call to undeclared function 'memrchr'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 
last = memrchr(domain, '.', len); 
^ 
cookie.c:253:8: error: incompatible integer to pointer conversion assigning to 'const char *' from 'int' [-Wint-conversion] 
last = memrchr(domain, '.', len); 
^ ~~~~~~~~~~~~~~~~~~~~~~~~~