c - 错误 : dereferencing pointer to incomplete type

Question

查看了许多与此相关的其他 SO 帖子，但没有一个能够帮助我。所以，我定义了以下结构:

 typedef struct
    {
    int created;
    double data;
    int timeLeft;
    int destination;
}dataPacket;

typedef struct
{
    dataPacket *array;
    int currIndex;
    int firstIndex;
    int nextTick;
    int maxLength;
    int length;
    int stime;
    int total;


}packetBuffer;

typedef struct{
    int mac;
    struct wire *lconnection;
    struct wire *rconnection;
    int numRecieved;
    struct packetBuffer *buffer;
    int i;
    int backoff;
}node;

typedef struct{
    float length;
    float speed;
    int busy;
    struct dataPacket *currPacket;
    struct node *lnode;
    struct node *rnode;
}wire;

然后我尝试使用以下函数:

    int sendPacket(node *n, int tick)
{
    if(n->buffer->length > 0)
    {
        if(n->backoff <= 0)
        {
            if (n->lconnection->busy != 0 || n->lconnection->busy != 0)
            {
                n->i++;
                n->backoff = (512/W * genrand()*(pow(2,n->i)-1))/TICK_LENGTH;
            }
            else
            {
                n->lconnection->busy = 1;
                n->rconnection->busy = 1;
                n->lconnection->currPacket = n->buffer[n->buffer->currIndex];
                n->rconnection->currPacket = n->buffer[n->buffer->currIndex];
            }
        }
        else
        {
            n->backoff--;
        }
    }
}

每次尝试访问缓冲区、lconnection 或 rconnection 的成员时，我都会收到标题中描述的错误。

Answer 1

struct packetBuffer *buffer;

您已经定义了一个类型 packetBuffer(一个匿名结构的 typedef)。

你还没有定义struct packetBuffer。

在没有现有类型 struct packetBuffer 的情况下，编译器将其视为不完整类型，假设您稍后会完成它。声明

struct packetBuffer *buffer;

是完全合法的，但是您不能取消引用 buffer 除非类型 struct packetBuffer 可见。

只需删除 struct 关键字即可。

(我个人的偏好是放弃 typedef 并始终将结构类型称为 struct whatever，但这是风格和品味的问题。)