MISRA C++ 9.6.2

[gdavis]

Hello,
My question is about the third example for MISRA C++ 2023 Rule 9.6.2: "A goto statement shall reference a label in a surrounding block".

void f3(int32_t i, int32_t x, int32_t y)
{
  switch( i )
  {                                   // statement A
    case 0:
      if ( x < y )
        goto L3;                      // Non-compliant
      break;
    case 1:
    L3:
      break;
  }
}

I am not sure why this is non-compliant. In terms of the amplification of the rule, "A goto statement shall be enclosed in a statement that directly encloses its reference label", statement A is the compound statement as shown above. I believe the goto statement is enclosed within statement A, and statement A directly-encloses the reference label (L3).

The MISRA C 2012 and MISRA C 2023 versions of the equivalent rule 15.3 provide a different amplification that directly addresses this: "A switch-clause that does not consist of a compound statement is treated as if it were a block"

Please let me know what you think. Thank you.

[misra cpp]

You're right that the goto is enclosed by the IF, the labelled statement case 0 and the switch body, however L3 is only directly enclosed by the labelled statement case 1 - so is not allowed by this rule.

In addition, the label L3 is part of a switch label group, which is not allowed by 9.4.2 amplification item 3.