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+---- Forum: 8.14 Control statement expressions (https://forum.misra.org.uk/forumdisplay.php?fid=169)
+---- Thread: 14.3 and enum constants in macro expansion (/showthread.php?tid=1660)
14.3 and enum constants in macro expansion - Timofei - 19-10-2023
Hi,
We have a configuration macro with a value being an enum constant. We use that macro in an if-statement, and it violates the rule 14.3.
Code:
enum my_enum {
MY_ENUM
};
#define CONF_MACRO MY_ENUM
if (CONF_MACRO == MY_ENUM) {...}Note that in the case of enum constants we cannot convert the if-statement to a preprocessor #if-statement since the values of enum constants are not known at the preprocessing step. How can we solve this issue?
RE: 14.3 and enum constants in macro expansion - misra-c - 24-03-2024
It is recognised that, sometimes, violations of Guidelines will happen...
In this instance, MISRA C have published a permit [Permit / MISRA / C:2012 / R-14.3.A.1] which provides assistance in deviating Rule 14.3 due to build configurations.
https://www.misra.org.uk/app/uploads/2021/06/MISRA-C-2012-Permits-First-Edition.pdf