What tools make it easier to learn someone else's code?

Question

PHP

Hello! Are there any tools that help to study someone else's code, help in debugging the code? Now I use xdebug, debug_backtrace.
For example, there is this code:

function a($value)
{
    b($value);
}

function b($value)
{
    c($value * 2);
}

function c($value)
{
    return $value / 2;
}

a(10);

Let's say all these functions are declared in completely different files and the call a()too. In order to get the call stack, I do this:

function c($value)
{
    var_dump(debug_backtrace());
    return $value / 2;
}

But this, in my opinion, is not very convenient. you still have to run through all the files to view the body of these functions. Maybe there is some tool for this that will return not only the call stack, but also the body of each function and, in general, all the information that will help to get the big picture?
In general, any information / tools that help in parsing someone else's code and debugging it are of interest. Thanks in advance!

Answer 1

Linters/static analyzers.
And a high-quality IDE, for example, PHPStorm, - the process of jogging to the body is reduced to pressing one hot key.