Generalized Question about #12.6 and Preprocessor Directives

[misra-c]

While Rule 12.6 doesn't explicitly mention expressions used in preprocessing directlves, it is intended to apply to all expressions.

In considering the question, it seems that there are two omissions from the definition of Boolean expressions in the Glossary (Appendix E), namely:

• the 'defined' proprocessing operator produces a Boolean-by-construct value
  
• a Boolean value is expected as the operand of the #if and #elif directives