13-07-2010, 08:53 AM
The previous poster is not quite correct. Defining your own version of errno does not violate Rule 20.5. However, reusing any identifiers reserved for use by the standard library does violate Rule 20.2 (note, not Rule 20.1 as stated by the previous poster which prohibits redefinition using macros).
Posted by and on behalf of the MISRA C Working Group