SDK版本5.1.0，使能CAN组件，硬件过滤器，在can.c中hdr提示未初始化告警

发布于 2024-09-24 16:55:41 浏览：177 订阅该版

提示告警信息：
```
../rt-thread/components/drivers/can/can.c:863:17: warning: 'hdr' may be used uninitialized in this function [-Wmaybe-uninitialized]
```
can.c头文件信息：

```c
include <rthw.h>  
include <rtthread.h>  
include <rtdevice.h>
```

can.h头文件信息：
```c
include <rtthread.h>  
include <rtdevice.h>
```
源文件函数代码如下：
```c
void rt_hw_can_isr(struct rt_can_device *can, int event)
{
    switch (event & 0xff)
    {
    case RT_CAN_EVENT_RXOF_IND:
    {
        rt_base_t level;
        level = rt_hw_interrupt_disable();
        can->status.dropedrcvpkg++;
        rt_hw_interrupt_enable(level);
    }
    case RT_CAN_EVENT_RX_IND:
    {
        struct rt_can_msg tmpmsg;
        struct rt_can_rx_fifo *rx_fifo;
        struct rt_can_msg_list *listmsg = RT_NULL;
#ifdef RT_CAN_USING_HDR
        rt_int8_t hdr;
#endif
        int ch = -1;
        rt_base_t level;
        rt_uint32_t no;

rx_fifo = (struct rt_can_rx_fifo *)can->can_rx;
        RT_ASSERT(rx_fifo != RT_NULL);
        /* interrupt mode receive */
        RT_ASSERT(can->parent.open_flag & RT_DEVICE_FLAG_INT_RX);

no = event >> 8;
        ch = can->ops->recvmsg(can, &tmpmsg, no);
        if (ch == -1) break;

/* disable interrupt */
        level = rt_hw_interrupt_disable();
        can->status.rcvpkg++;
        can->status.rcvchange = 1;
        if (!rt_list_isempty(&rx_fifo->freelist))
        {
            listmsg = rt_list_entry(rx_fifo->freelist.next, struct rt_can_msg_list, list);
            rt_list_remove(&listmsg->list);
#ifdef RT_CAN_USING_HDR
            rt_list_remove(&listmsg->hdrlist);
            if (listmsg->owner != RT_NULL && listmsg->owner->msgs)
            {
                listmsg->owner->msgs--;
            }
            listmsg->owner = RT_NULL;
#endif /*RT_CAN_USING_HDR*/
            RT_ASSERT(rx_fifo->freenumbers > 0);
            rx_fifo->freenumbers--;
        }
        else if (!rt_list_isempty(&rx_fifo->uselist))
        {
            listmsg = rt_list_entry(rx_fifo->uselist.next, struct rt_can_msg_list, list);
            can->status.dropedrcvpkg++;
            rt_list_remove(&listmsg->list);
#ifdef RT_CAN_USING_HDR
            rt_list_remove(&listmsg->hdrlist);
            if (listmsg->owner != RT_NULL && listmsg->owner->msgs)
            {
                listmsg->owner->msgs--;
            }
            listmsg->owner = RT_NULL;
#endif
        }
        /* enable interrupt */
        rt_hw_interrupt_enable(level);

if (listmsg != RT_NULL)
        {
            rt_memcpy(&listmsg->data, &tmpmsg, sizeof(struct rt_can_msg));
            level = rt_hw_interrupt_disable();
            rt_list_insert_before(&rx_fifo->uselist, &listmsg->list);
#ifdef RT_CAN_USING_HDR
            hdr = tmpmsg.hdr_index;
            if (can->hdr != RT_NULL)
            {
                RT_ASSERT(hdr < can->config.maxhdr && hdr >= 0);
                if (can->hdr[hdr].connected)
                {
                    rt_list_insert_before(&can->hdr[hdr].list, &listmsg->hdrlist);
                    listmsg->owner = &can->hdr[hdr];
                    can->hdr[hdr].msgs++;
                }

}
#endif
            rt_hw_interrupt_enable(level);
        }

/* invoke callback */
#ifdef RT_CAN_USING_HDR
        if (can->hdr != RT_NULL && can->hdr[hdr].connected && can->hdr[hdr].filter.ind)
        {
            rt_size_t rx_length;
            RT_ASSERT(hdr < can->config.maxhdr && hdr >= 0);

level = rt_hw_interrupt_disable();
            rx_length = can->hdr[hdr].msgs * sizeof(struct rt_can_msg);
            rt_hw_interrupt_enable(level);
            if (rx_length)
            {
                can->hdr[hdr].filter.ind(&can->parent, can->hdr[hdr].filter.args, hdr, rx_length);
            }
        }
        else
#endif
        {
            if (can->parent.rx_indicate != RT_NULL)
            {
                rt_size_t rx_length;

level = rt_hw_interrupt_disable();
                /* get rx length */
                rx_length = rt_list_len(&rx_fifo->uselist)* sizeof(struct rt_can_msg);
                rt_hw_interrupt_enable(level);

if (rx_length)
                {
                    can->parent.rx_indicate(&can->parent, rx_length);
                }
            }
        }
        break;
    }

case RT_CAN_EVENT_TX_DONE:
    case RT_CAN_EVENT_TX_FAIL:
    {
        struct rt_can_tx_fifo *tx_fifo;
        rt_uint32_t no;
        no = event >> 8;
        tx_fifo = (struct rt_can_tx_fifo *) can->can_tx;
        RT_ASSERT(tx_fifo != RT_NULL);

if ((event & 0xff) == RT_CAN_EVENT_TX_DONE)
        {
            tx_fifo->buffer[no].result = RT_CAN_SND_RESULT_OK;
        }
        else
        {
            tx_fifo->buffer[no].result = RT_CAN_SND_RESULT_ERR;
        }
        rt_completion_done(&(tx_fifo->buffer[no].completion));
        break;
    }
    }
}
```

看到论坛里面这种问题一般是没有添加对应的头文件引起的，试了几个都不行，不知道是哪的原因