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MISRA C++:2008 Rule 3-9-1

The types used for an object, a function return type, or a function parameter shall be token-for-token identical in all declarations and re-declarations

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Description

Rule Definition

The types used for an object, a function return type, or a function parameter shall be token-for-token identical in all declarations and re-declarations.

Rationale

If a redeclaration is not token-for-token identical to the previous declaration, it is not clear from visual inspection which object or function is being redeclared.

Polyspace Implementation

The rule checker compares the current declaration with the last seen declaration.

Additional Message in Report

The types used for an object, a function return type, or a function parameter shall be token-for-token identical in all declarations and re-declarations.

Variable varName is not compatible with previous declaration.

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

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typedef int* intptr;

int* map;
extern intptr map; //Noncompliant

intptr table;
extern intptr table; //Compliant

In this example, the variable map is declared twice. The second declaration uses a typedef which resolves to the type of the first declaration. Because of the typedef, the second declaration is not token-for-token identical to the first.

Check Information

Group: Basic Concepts
Category: Required

Version History

Introduced in R2013b

See Also

Topics