问MPLAB X中的有效代码和编译器错误

EN

#include "modbus.h"

void main(void)
{
    modbus_frame_t frame;
    // (...)   

    // ERROR ON LINE BELOW
    // main.c:59:: error: (712) can't generate code for this expression
    crc16(frame, 1); 
}

#ifndef MODBUS_H
#define MODBUS_H

#define MODBUS_FRAME_BUFFER_SIZE 74

struct modbus_frame {
    unsigned char * data[MODBUS_FRAME_BUFFER_SIZE];
    unsigned char * len; 
};

typedef struct modbus_frame modbus_frame_t;

char crc16(modbus_frame_t f, char check);

#endif

#include "modbus.h"

char crc16(modbus_frame_t f, char check) {
    // (...)
}

struct modbus_frame {
    unsigned char data[MODBUS_FRAME_BUFFER_SIZE];
    unsigned char len; 
};