MISRA C:2012 Rule 2.7

A function should not contain unused parameters

Description

Rule Definition

A function should not contain unused parameters.

Rationale

If a parameter is unused, it is possible that the implementation of the function does not match its specifications. This rule can highlight such mismatches.

Additional Message in Report

There should be no unused parameters in functions.

Parameter parameter_name is not used.

Troubleshooting

If you expect a rule violation but do not see it, refer to Diagnose Why Coding Standard Violations Do Not Appear as Expected.

Examples

Unused Function Parameters

double func(int param1, int* param2) { /* Non-compliant */
    return (param1/2.0);
}

In this example, the rule is violated because the parameter param2 is not used.

Check Information

Group: Unused code

Category: Advisory

AGC Category: Readability

Version History

Introduced in R2015b

R2024b: Rule Definition Changed

Following MISRA C:2012 Amendment 4, the rule definition is changed to "A function should not contain unused parameters".