# V3142. Unreachable code detected. It is possible that an error is present.

The analyzer has detected a block of code that will never be executed. This may indicate an error in the program's logic.

This diagnostic detects code blocks that will never get control.

Consider the following example:

    static void Foo()
    {
      Environment.Exit(255);
      Console.WriteLine("Hello World!");
    }

The 'Console.WriteLine (....)' function is unreachable because the 'Exit()' function does not return control. The exact fix depends on what logic was originally intended by the developer. Perhaps the expressions were written in the wrong order, and the correct version should then look like this:

    static void Foo()
    {
      Console.WriteLine("Hello World!");
      Environment.Exit(255);
    }

Consider another example:

    static void ThrowEx()
    {
      throw new Exception("Programm Fail");
    }
    public void SetResponse(int response)
    {
      ThrowEx();
      Debug.Assert(false); //should never reach here
    }

In this example, the interprocedural analysis checks the 'ThrowEx' method and warns that the code below the method call is unreachable. If you expect such behavior in your program, you can mark this warning as a false positive.

    public void SetResponse(int response)
    {
      ThrowEx();
      Debug.Assert(false); //should never reach here //-V3142
    }

This diagnostic is classified as:

CWE-561

You can look at examples of errors detected by the V3142 diagnostic.