MISRA C++:2008 Rule 6-6-5

A function shall have a single point of exit at the end of the function

Description

Rule Definition

A function shall have a single point of exit at the end of the function.¹

Rationale

This rule requires that a return statement must occur as the last statement in the function body. Otherwise, the following issues can occur:

• Code following a return statement can be unintentionally omitted.

• If a function that modifies some of its arguments has early return statements, when reading the code, it is not immediately clear which modifications actually occur.

Polyspace Implementation

The checker flags these situations:

• A function has more than one return statement.

• A non-void function has one return statement only but the return statement is not the last statement in the function.

A void function need not have a return statement. If a return statement exists, it need not be the last statement in the function.

Troubleshooting

If you expect a rule violation but Polyspace^® does not report it, see Diagnose Why Coding Standard Violations Do Not Appear as Expected.

Check Information

Group: Statements

Category: Required

Version History

Introduced in R2013b

R2024b: return statement as the last line of a do-while statement

Polyspace does not report a violation of this rule when a return statement is the last line of the do portion of a do-while statement. For example:

uint8_t exampleA(void) {
     do {
          uint8_t a;
          a = get_uint8();
          return(a);            //Compliant
     }
     while (0);
}