Question

我正在使用redis的sds库并在其上运行scan-build。然后我得到两个错误，非常相似。我将在这里提出一个错误。

sds.c:92:22: warning: Out of bound memory access (accessed memory precedes memory block)
sh->buf[initlen] = '\0';

有问题的功能是：

    /* Create a new sds string with the content specified by the 'init' pointer
     * and 'initlen'.
     * If NULL is used for 'init' the string is initialized with zero bytes.
     *
     * The string is always null-termined (all the sds strings are, always) so
     * even if you create an sds string with:
     *
     * mystring = sdsnewlen("abc",3");
     *
     * You can print the string with printf() as there is an implicit \0 at the
     * end of the string. However the string is binary safe and can contain
     * \0 characters in the middle, as the length is stored in the sds header. */
    sds sdsnewlen(const void *init, size_t initlen) {
        struct sdshdr *sh;

        if (init) {
            sh = malloc(sizeof *sh+initlen+1);
        } else {
            sh = calloc(sizeof *sh+initlen+1,1);
        }
        if (sh == NULL) return NULL;
        sh->len = initlen;
        sh->free = 0;
        if (initlen && init)
            memcpy(sh->buf, init, initlen);
        sh->buf[initlen] = '\0';
        return (char*)sh->buf;
    }

我真的不明白这个错误，我很确定这里没有错误，因为它是sds库的一个非常基础的部分，如果有错误的话，它本已在生产中显示出来。

我该如何解决这个问题？通过显式告诉cland-analyzer，这不是一个错误，或者通过更改代码使clang-analyzer感到高兴。

scan-build在sds上引发错误

0 个答案: