Examples of errors detected by the V551 diagnostic

V551. Unreachable code under a 'case' label.

Command & Conquer

V551 The code under this 'case' label is unreachable. The '4109' value of the 'char' type is not in the range [-128; 127]. WINDOWS.CPP 547

#define VK_RETURN 0x0D

typedef enum {
  ....
  WWKEY_VK_BIT    = 0x1000,
  ....
}

enum {
  ....
  KA_RETURN = VK_RETURN | WWKEY_VK_BIT,
  ....
}

void Window_Print(char const string[], ...)
{
  char c; // Current character.
  ....
  switch(c) {
    ....
    case KA_FORMFEED: // <= 12
        New_Window();
        break;
    case KA_RETURN:   // <= 4109
      Flush_Line();
      ScrollCounter++;
      WinCx = 0;
      WinCy++;
      break;
    ....
  }
  ....
}

Similar errors can be found in some other places:

• V551 The code under this 'case' label is unreachable. The '4105' value of the 'char' type is not in the range [-128; 127]. WINDOWS.CPP 584
• V551 The code under this 'case' label is unreachable. The '4123' value of the 'char' type is not in the range [-128; 127]. WINDOWS.CPP 628