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Acceptable Escape Sequences? - Printable Version

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Acceptable Escape Sequences? - gs - 25-04-2008

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?

Re: Acceptable Escape Sequences? - Lundin - 29-04-2008

Hexadecimal is not allowed.

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

Re: Acceptable Escape Sequences? - gs - 06-05-2008

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

Re: Acceptable Escape Sequences? - misra-c - 21-05-2008

MISRA-C 1998 has been superceded by MISRA-C 2004 as amended by TC1.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