# V3516. AUTOSAR. A switch-label should only appear at the top level of the compound statement forming the body of a 'switch' statement.

This diagnostic rule is based on the software development guidelines developed by AUTOSAR (AUTomotive Open System ARchitecture).

A label's scope should be a compound statement forming the body of the 'switch' statement. It means that the label should not be nested in any block other than the body of the 'switch', and that body should be a compound statement.

Therefore, all labels of one 'switch' should belong to the same scope. Following this rule helps to keep the code clear and well-structured.

Example 1:

    void example_1(int param, bool b)
    {
      switch (param)
      {
      case 1:
        DoSmth1();
        if (b)
        {
      case 2: // <=
        DoSmth2();
        }
        break;
      default:
        assert(false);
        break;
      }
    }

This code is not clear enough. To eliminate the warning, rewrite the code as follows:

    void example_1(int param, bool b)
    {
      switch (param)
      {
      case 1:
        DoSmth1();
        if (b)
        {
          DoSmth2();
        }
        break;
      case 2:
        DoSmth2();
        break;
      default:
        assert(false);
        break;
      }
    }

The following example will also trigger the warning because the body of the 'switch' statement is not compound:

    void example_2(int param)
    {
      switch (param)
        default:
          DoDefault();
    }

Fixed code:

    void example_2(int param)
    {
      switch (param)
      {
        default:
          DoDefault();
          break;
      }
    }

This diagnostic is classified as:

AUTOSAR-M6.4.4