V3013. It is odd that the body of 'Foo_1' function is fully equivalent to the body of 'Foo_2' function.


The analyzer outputs this warning when it detects two functions implemented in the same way. The presence of two identical functions in code is not an error in itself, but such code should be inspected.

This diagnostic is meant for detecting the following type of bugs:

class Point
{
  ....
  float GetX() { return m_x; }
  float GetY() { return m_x; }
};

A typo makes two different functions do the same thing. This is the correct version of this code:

float GetX() { return m_x; }
float GetY() { return m_y; }

In the example above, the bodies of the functions GetX() and GetY() being alike is obviously a sign of a bug. However, there would be too many false positives if we set the analyzer to output this warning every time it encounters functions with identical bodies. That's why it relies on a number of exceptions for cases when it shouldn't output the warning. Such cases include the following:

  • Functions with identical bodies use no other variables but arguments. For example: "bool IsXYZ() { return true; }";
  • Functions with identical bodies are repeated more than twice;
  • The functions' bodies consist of only the throw() statement;
  • Etc.

There are a number of ways to handle the false positives. If they relate to the files of external libraries or tests, you can add the path to these files or folders into the exception list. If they relate to your own code, you can add the "//-V3013" comment to suppress them. If there are too many false positives, you can disable this diagnostic completely from the analyzer's settings. Also, you may want to modify the code so that one function calls another.

The following is a code sample from a real-life application where functions meant to do different work are implemented in the same way:

public void Pause(FrameworkElement target)
{
  if (Storyboard != null)
  {
    Storyboard.Pause(target);
  }
}

public void Stop(FrameworkElement target)
{
  if (Storyboard != null)
  {
    Storyboard.Stop(target);
  }
}

public void Resume(FrameworkElement target)
{
  if (Storyboard != null)
  {
    Storyboard.Pause(target);
  }
}

Having made a few copies of one function, the programmer forgot to modify the last of them, function Resume().

The correct version of this fragment should look like this:

public void Resume(FrameworkElement target)
{
  if (Storyboard != null)
  {
    Storyboard.Resume(target);
  }
}

Bugs Found

Checked Projects
334
Collected Errors
12 668