MISRA classify_number()

perfect_numbers.c

kind classify_number(int n)
{
    kind class = error;
    if (n > 0) {
        int buf = aliquot_sum(n);
        if (buf > n) {
            class = abundant_number;
        } else if (buf < n) {
            class = deficient_number;
        } else {
            class = perfect_number;
        }
    }
    return class;
}

oh this looks good 👍

TY @deathsec.
Bear in mind that in a general case this would change if for some reason we were using a float or a double because they can have NaN values, which means the if is not complete. In that case, to code defensively I might do:

kind classify_number(float n)
{
    kind class = error;
    if (n > 0) { // This still protects against incorrect parameter
        float buf = foo(n); // But this could return NaN
        if (buf > n) {
            class = abundant_number;
        } else if (buf < n) {
            class = deficient_number;
        } else if (buf == 0) { // Zero is explicitly tested for, as it is a non-error value
            class = perfect_number;
        } else { // The if still has a finishing else after all the else-if
            class = error; // And the else catches the error case (NaN value in this case)
        }
    }
    return class; // Still only one exit point
}