c - 处理双重间接时避免不兼容的指针警告

Question

假设这个程序:

#include <stdio.h>
#include <string.h>

static void ring_pool_alloc(void **p, size_t n) {
    static unsigned char pool[256], i = 0;
    *p = &pool[i];
    i += n;
}

int main(void) {
    char *str;
    ring_pool_alloc(&str, 7);
    strcpy(str, "foobar");
    printf("%s\n", str);
    return 0;   
}

...是否有可能以某种方式避免 GCC 警告

test.c:12: warning: passing argument 1 of ‘ring_pool_alloc’ from incompatible pointer type
test.c:4: note: expected ‘void **’ but argument is of type ‘char **’

... 没有强制转换为 (void**) (或者只是禁用兼容性检查)？因为我非常想保留有关间接级别的兼容性警告...

Answer 1

为什么不更改方法签名，使其返回新指针而不是通过指针传递它？事实上，就像常规的 malloc 一样:

static void * ring_pool_alloc(size_t n) {
    static unsigned char pool[256], i = 0;
    void *p = &pool[i];
    i += n;
    return p;
}

int main(void) {
    char *str = ring_pool_alloc(7);
    strcpy(str, "foobar");
    printf("%s\n", str);
    return 0;   
}