MISRA Discussion Forums

Hi,
Rule 4.1 states

Quote:Only those escape sequences that are defined in the ISO C standard shall be used.

The explanatory text then refers the Reader to section 5.2.2 of the C99 Standard for a list of escape sequences. However, 6.4.4.4 also defines an escape-sequence syntax as

Code:
escape-sequence:

       simple-escape-sequence

       octal-escape-sequence

       hexadecimal-escape-sequence

       universal-character-name

and a hexadecimal-escape-sequence as

Code:
hexadecimal-escape-sequence:

       \x hexadecimal-digit

       hexadecimal-escape-sequence hexadecimal-digit

The use of '\x' i not mentioned in 5.2.2 as a valid escape-sequence. Are hexadecimal escape-sequences permitted under MISRA 2004 Rule 4.1?

Hexadecimal is not allowed.

You will want to download the Technical Corrigendum 1, which clarifies rule 4.1, among other things.

Does this prohibition apply to MISRA C 1998, Rule 5, as well?

MISRA-C 1998 has been superceded by MISRA-C 2004 as amended by TC1.

MISRA have no plans to provide further direction on MISRA-C 1998.

MISRA are offering no direction on how to apply subsequent changes to obsolete versions of the document.

Note: Both MISRA-C 1998 and MISRA-C 2004 & TC1 are based on the 1990 version of the C standard, and not the 1999 version.

gs

Lundin

gs

misra-c