objective-c - Mac OS X 相当于 SecureZeroMemory/RtlSecureZeroMemory？

Question

Mac OS X 是否有等同于 RtlSecureZeroMemory 的版本？/SecureZeroMemory ，一个将内存块清零的函数，但调用不会被编译器优化掉？

Answer 1

编写自己的函数:

void secure_zero(void *s, size_t n)
{
    volatile char *p = s;

    while (n--) *p++ = 0;
}

编辑:评论中的问题，为什么不用memset？如果不再访问数组对象，编译器可以优化 memset 函数调用。

请注意，C11 添加了(可选)函数 memset_s 并且标准保证函数调用不会被优化掉:

(C11, K.3.7.4.1p4) "[...] Unlike memset, any call to the memset_s function shall be evaluated strictly according to the rules of the abstract machine as described in (5.1.2.3). That is, any call to the memset_s function shall assume that the memory indicated by s and n may be accessible in the future and thus must contain the values indicated by c."