MISRA C++:2008 Rule 0-1-1

A project shall not contain unreachable code

Description

Rule Definition

A project shall not contain unreachable code.¹

Rationale

This rule flags situations where a group of statements is unreachable because of syntactic reasons. For instance, code following a return statement are always unreachable.

Unreachable code involve unnecessary maintenance and can often indicate programming errors.

Polyspace Implementation

Polyspace^® reports a defect if a statement in your code is not reachable.

Troubleshooting

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

Examples

expand all

Unreachable statements

int func(int arg) {
 int temp = 0;
 switch(arg) {
     temp = arg; // Noncompliant
     case 1:
     {
         break;
     }
     default:
     {
         break;
     }
 }
 return arg;
 arg++; // Noncompliant
}

These statements are unreachable:

Statements inside a switch statement that do not belong to a case or default block.
Statements after a return statement.

Check Information

Group: Language Independent Issues

Category: Required

Version History

Introduced in R2013b