MISRA C:2025 Rule 20.5

R2026b

#undef should not be used

Since R2026b

Description

#undef should not be used ¹ .

Rationale

#undef can make the software unclear which macros exist at a particular point within a translation unit.

Troubleshooting

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

Check Information

Group: Preprocessing Directives

Category: Advisory

AGC Category: Disapplied

PQL Name: std.misra_c_2025.R20_5

Version History

Introduced in R2026b

See Also

Topics

Check for and Review Coding Standard Violations

¹ All MISRA coding rules and directives are © Copyright The MISRA Consortium Limited 2021.

The MISRA coding standards referenced in the Polyspace^® Bug Finder™ documentation are from the following MISRA standards:

MISRA C:2004
MISRA C:2012
MISRA C:2023
MISRA C:2025
MISRA C++:2008
MISRA C++:2023

MISRA and MISRA C are registered trademarks of The MISRA Consortium Limited 2021.