Function Stress Complexity

Complexity of internal structure and external connections of a function

Description

The metric Function Stress Complexity (FSC) is a measure of the complexity of the internal structure and external connections of a function. If the internal structure of a function is complex, its FSC is high. If a function calls many other function or is called by many other function, its FSC is high. A function with a high FSC indicates a possible bottleneck in your code base.

Computation Details

For a function foo(), Polyspace^® computes FSC using this formula:

FSC = C ⋅ (N_calling ⋅ N_calls)²

In this formula:

• C is the metric Cyclomatic Complexity of the foo().

• N_calling is the metric Number of Calling Functions, the number of functions that call foo().

• N_calls is the metric Number of Called Functions, the number of function called by foo().

The terms N_calling and N_calls represent the complexity of the external connections of foo(), while C represents the complexity of the internal structure of the function. The minimum values of N_calling and N_calls are 1. That is, if foo() does not call any other function, N_calls is 1. If foo() is not called by any other function, N_calling is 1.

This metric is equivalent to the MISRA software metric Component Stress Complexity.

Examples

Find Function Stress Complexity of C Function

Find the function stress complexity (FSC) of the function processInput() using the formula

FSC = C ⋅ (N_calling ⋅ N_calls)²

The function has two control flow structures, the for statement and the if statement,leading to a cyclomatic complexity of 3. No function in this code calls processInputs(), so N_calling is 1. The function processInputs() calls two other functions, so N_calls is 2. The FSC for processInputs() is given by:

FSC = 3 ⋅ (1⋅2)² = 12

.

int processInput(int x);
int auxiliaryFunction1(int x);
int auxiliaryFunction2(int x);



int processInput(int x) {
    int result = 0;
    for (int i = 0; i < x; ++i) { 
        if (i % 2 == 0) { 
            result += auxiliaryFunction1(i);
        } else {
            result += auxiliaryFunction2(i);
        }
    }
    return result;
}

Metric Information

Group: Function

Acronym: FSC

HIS Metric: No