outofbound.mj

编译器mips版后端

/**
 * This program is used to test whether your compiler can find out
 * the out-of-bound operations of array. For those operations that
 * can't be checked out at compile-time, your compiler should 
 * generate codes to check them at runtime.
 * The following program is wrong. Your compiler should find out the
 * errors as many as possible. And it's better to point out the exact
 * positions of the errors and output useful information.
 */
 
class Program {
    static void main() {
        int[10] array;
        
        array[-1] = -1;  // ERROR: out of the lower bound. This error
                         // should be checked out at compile-time.
        array[10] = 10;  // ERROR: out of the upper bound. This error
                         // should be checked out at compile-time.
                         
        int i = -1;
        // ERROR: There are illegal array accesses that is out of bound
        // in the following loop. If your compiler can't check out them,
        // be sure they can be checked out at runtime before the crash.
        while (i<=10) {
            array[i] = i;
        }
        
        return;
    }
}