[求助] gdb调试C语言问题

#include <stdio.h>

int getinput(void);
void printmessage(int counter, int input);

int main(void)
{   
    int counter;
    int input;
   
    for(counter=0;counter<=200;counter++)
    {
        input = getinput();
        if (input==-1)
            break;
        printmessage(counter,input);
    }
   
    return 0;
}

int getinput(void)
{
    int input;
   
    printf("Enter an integer, or use -1 to exit:\n");
    scanf("%d",&input);
    return input;
}

void printmessage(int counter, int input)
{
    static int lastnum = 0;
    counter++;
   
    printf("For number %d, you entered %d (%d more than last time)\n",counter,input,input-lastnum);
    lastnum = input;
}