# V785. Constant expression in switch statement.

The analyzer detected a constant expression in a 'switch' statement. This usually indicates the presence of a logic error in the code.

Consider the following synthetic example:

    int i = 1;
    switch (i)
    {
      ....
    }

The condition of the 'switch' statement is represented by a variable whose value can be computed at compilation time. This situation could have resulted from code refactoring: the previous version of the code changed the variable's value but then it was modified and the variable turned out to be no longer assigned any value.

The analyzer does not issue the warning when the variable is constant or when the condition employs macros. Such constructs are usually used deliberately to switch on/off various features of the program at compilation time.

For example, they could perform different actions depending on what operating system the code was compiled for:

    switch (MY_PROJ_OS)
    {
    case MY_PROJ_WINDOWS:
      ....
    case MY_PROJ_LINUX:
      ....
    case MY_PROJ_MACOS:
      ....
    }

This diagnostic is classified as:

CWE-691 CERT-MSC01-C