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Code that is never executed is known as dead code. Typically, the presence of dead code indicates that a logic error has occurred as a result of changes to a program over time. Dead code is usually optimized out of a program during compilation. However, to improve readability and ensure that logic errors are resolved dead code should be identified, understood, and removed from a program.

Non-Compliant Code Example

This example, inspired by Fortify demonstrates how dead code can be introduced into a program. The second conditional statement, if (s) may never evaluate true because it requires that s not be assigned NULL. However, the only path where s can be assigned a non-NULL value ends with a return statement.

int func(int condition) {
    int *s = NULL;
    if (condition) {
        s = malloc(10);
        if (s == NULL) {
           /* Handle Error */
        }
        /* insert data into s */
        return 0;
    }
    /* ... */
    if (s) {
        /* This code is never reached */
    }
}
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