What tools are available to visually analyse source code?

For example you have Doxygen. Or say I wanted to maybe create a UML flowchart of the source, or some other form of visual representation, what tools are available out there?

Something that will show me how everything is connected.

Another way of looking at it is, you could have all source in one CPP file, everything, but it’s obviously split into many files, you start of with initializing the graphics drivers and then you start the game loop.

As there are so many files it’s hard to work out what happens next, you could debug through everything and maybe that is the best tool to use, but I was wondering if there is some 3rd party source code visual analyzer to show exactly what is happening, or at least give an overview.

Now I know it’s all dependent on user input, i.e dynamic and the functions, classes, variables or whatever are called when asked of, so maybe what I am asking is not really possible. But I thought I’d ask.

There is VisualStudio CodeMap which can visualize the entire C++ solution, to help understand Code Architecture. But it seems not work with the UE4 project code. Check out my question.