No Enumeration Ranges in Case Constructs (RPP02)

Level \(\rightarrow\) Required

Category

Safety:

\(\checkmark\)

Cyber:

\(\checkmark\)

Goal

Maintainability:

\(\checkmark\)

Reliability:

\(\checkmark\)

Portability:

\(\checkmark\)

Performance:

Security:

Remediation \(\rightarrow\) Low

Verification Method \(\rightarrow\) GNATcheck rule: Enumeration_Ranges_In_CASE_Statements

Reference

Similar to RPP01

Description

A range of enumeration literals must not be used as a choice in a case statement or a case expression. This includes explicit ranges (A .. B), subtypes, and the 'Range attribute. Much like the use of others in case statement alternatives, the use of ranges makes it possible for a new enumeration value to be added but not handled with a specific alternative, when a specific alternative was intended.

Applicable Vulnerability within ISO TR 24772-2

• 6.5 Enumerator issues [CCB]

Noncompliant Code Example

   case Digit_T (C) is
      when '0' | '9' =>
         C := Character'succ (C);
      when '1' .. '8' =>
         C := Character'pred (C);
   end case;

Compliant Code Example

   case Digit_T (C) is
      when '0' | '9' =>
         C := Character'succ (C);
      when '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' =>
         C := Character'pred (C);
   end case;

Notes

N/A