警告：格式参数过多

Question

#include<stdio.h>
#include<errno.h>
#include<error.h>
#include<stdlib.h>

#define clean_errno() (errno == 0 ? "None" : strerror(errno))
#define DEBUG_ERROR(M,...) fprintf(stderr, "[ERROR] (%s:%d: (error: %s)) M \n", __FILE__, __LINE__, clean_errno(),##__VA_ARGS__)

int main()
{
   int test =10;
   DEBUG_ERROR("Test variable %s = %d.\n","test",test);
   return 0;
}

Any ideas on how to fix the following warning with the debug macro...

warn.c:12:4: warning: too many arguments for format [-Wformat-extra-args]

Answer 1

Your macro should be:

#define DEBUG_ERROR(M,...) fprintf(stderr, "[ERROR] (%s:%d: (error: %s)) " M " \n", __FILE__, __LINE__, clean_errno(),##__VA_ARGS__)

Note that M is not in quotes now.