MISRA C:2012 Rule 6.2
Single-bit named bit-fields shall not be of a signed type
Description
Rule Definition
Single-bit named bit-fields shall not be of a signed type1 .
Rationale
According to the C99 Standard Section 6.2.6.2, a single-bit signed bit-field has one sign bit and no value bits. In any representation of integers, zero value bits cannot specify a meaningful value.
A single-bit signed bit-field is therefore unlikely to behave in a useful way. Its presence is likely to indicate programmer confusion.
Although the C90 Standard does not provide much detail regarding the representation of types, the same single-bit bit-field considerations apply.
Polyspace Implementation
This rule does not apply to unnamed bit fields because their values cannot be accessed.
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: Types |
| Category: Required |
| AGC Category: Required |
Version History
Introduced in R2014b
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++:2008
MISRA C++:2023
MISRA and MISRA C are registered trademarks of The MISRA Consortium Limited 2021.
