How to fix 13.3 MISRA-C 2012 Polyspace Warning?

A full expression containing an increment (++) or decrement (--) operator should have no other potential side effects other than that caused by the increment or decrement operator.

1.int input(void);

2.int choice(void);

3.int operation(int, int);

4.int func() {

5. int x = input(), y = input(), res;

6. int ch = choice();

7. if (choice == -1)

8. return(x++); /* Non-compliant */

9. if (choice == 0) {

10. res = x++ + y++; /* Non-compliant */

11. return(res);

12. }

13.}

--> from the above code,i am getting 13.3 warning for line no.8 and no.10, please answer how to fix 13.3 MISRA-C 2012 Warning.

Answer 1

[Walter Roberson]

Your x and y are automatic variables, local to func(). What is the purpose of incrementing them just before returning ?

Anyhow

https://stackoverflow.com/questions/54102531/how-to-resolve-misra-c2012-rule-13-2-and-13-3-for-c-code

Move the increments to be in expressions of their own. SO

if (choice == -1) {
    int old_x;
    old_x = x;
    x++;
    return(old_x);
}
if (choice == 0) {
    int old_x, old_y;
    old_x = x; old_y = y;
    x++; y++;
    res = old_x + old_y;
    return(res);
}

[Undali Muniranga]

Thank You for your answer !!