忽略"从不兼容的指针类型初始化"警告？

Question

是否有编译器指令,以忽略"从不兼容的指针类型初始化"警告Hardware_MouseDrivers_GPM_Methods和Hardware_MouseDrivers_DevInput_Methods？但是,全局关闭警告不是一种选择.

#include <stdio.h>

/* Mouse driver interface */

typedef struct _Hardware_MouseDriver {
        int (*open)(void*, char *);
        int (*close)(void*);
        int (*poll)(void*);
} Hardware_MouseDriver;

/* GPM */

typedef struct _Hardware_MouseDrivers_GPM {
        char *path;
} Hardware_MouseDrivers_GPM;

static int Hardware_MouseDrivers_GPM_Open(Hardware_MouseDrivers_GPM *this, char *path);
static int Hardware_MouseDrivers_GPM_Close(Hardware_MouseDrivers_GPM *this);
static int Hardware_MouseDrivers_GPM_Poll(Hardware_MouseDrivers_GPM *this);

static int Hardware_MouseDrivers_GPM_Open(Hardware_MouseDrivers_GPM *this, char *path) {
        printf("GPM: Opening %s...\n", path);
        this->path = path;
}

static int Hardware_MouseDrivers_GPM_Close(Hardware_MouseDrivers_GPM *this) {
        printf("GPM: Closing %s...\n", this->path);
}

static int Hardware_MouseDrivers_GPM_Poll(Hardware_MouseDrivers_GPM *this) {
        printf("GPM: Polling %s...\n", this->path);
}

Hardware_MouseDriver Hardware_MouseDrivers_GPM_Methods = {
        .open  = Hardware_MouseDrivers_GPM_Open,
        .close = Hardware_MouseDrivers_GPM_Close,
        .poll  = Hardware_MouseDrivers_GPM_Poll
};

/* DevInput */

typedef struct _Hardware_MouseDrivers_DevInput {
        char *path;
} Hardware_MouseDrivers_DevInput;

static int Hardware_MouseDrivers_DevInput_Open(Hardware_MouseDrivers_DevInput *this, char *path);
static int Hardware_MouseDrivers_DevInput_Close(Hardware_MouseDrivers_DevInput *this);
static int Hardware_MouseDrivers_DevInput_Poll(Hardware_MouseDrivers_DevInput *this);

static int Hardware_MouseDrivers_DevInput_Open(Hardware_MouseDrivers_DevInput *this, char *path) {
        printf("DevInput: Opening %s...\n", path);
        this->path = path;
}

static int Hardware_MouseDrivers_DevInput_Close(Hardware_MouseDrivers_DevInput *this) {
        printf("DevInput: Closing %s...\n", this->path);
}

static int Hardware_MouseDrivers_DevInput_Poll(Hardware_MouseDrivers_DevInput *this) {
        printf("DevInput: Polling %s...\n", this->path);
}

Hardware_MouseDriver Hardware_MouseDrivers_DevInput_Methods = {
        .open  = Hardware_MouseDrivers_DevInput_Open,
        .close = Hardware_MouseDrivers_DevInput_Close,
        .poll  = Hardware_MouseDrivers_DevInput_Poll
};

/* Test drivers */

void TestDriver(Hardware_MouseDriver driver, void *data) {
        /* Access the driver using a generic interface
         * (Hardware_MouseDriver) */
        driver.poll(data);
}

void main() {
        Hardware_MouseDrivers_GPM gpm;
        Hardware_MouseDrivers_DevInput devinput;

        Hardware_MouseDrivers_GPM_Open(&gpm, "/dev/gpmctl");
        Hardware_MouseDrivers_DevInput_Open(&devinput, "/dev/input/mice");

        TestDriver(Hardware_MouseDrivers_GPM_Methods, &gpm);
        TestDriver(Hardware_MouseDrivers_DevInput_Methods, &devinput);

        Hardware_MouseDrivers_GPM_Close(&gpm);
        Hardware_MouseDrivers_DevInput_Close(&devinput);
}

Answer 1

将赋值转换为正确的类型(函数指针使用void*而不是实例指针):

 .open= (int (*)(void*, char *))Hardware_MouseDrivers_GPM_Open;

或者创建一个类型并在结构的定义和初始化中使用它:

typedef int (*openfcnt_t)(void*, char *);

typedef struct _Hardware_MouseDriver {
        openfnct_t open;
} Hardware_MouseDriver;

然后

 .open= (openfnct_t)Hardware_MouseDrivers_GPM_Open;

编辑:

进一步思考C程序的最简单和最简单的方法是:

 .open= (void *)Hardware_MouseDrivers_GPM_Open;