Stack And Functions

Function and stack might seem unrelated when you work at high level. At low level, these are in a very inseparable relationship. You can’t study one without other.

• If stack is an idea, function is its best implementation.
• If function is an idea, it can’t exist in its best form without stack.

To understand their relationship, we have to move slow enough that we don’t gloss over anything and fast enough that we don’t dry ourselves up. Here is the progression:

1. Introduction introduces to the idea of functions and stack at assembly level. Although it dives deep into theory, it will not feel like that because I have included real-life examples, interactive questions, gradual flow and introduction, ASCII art and a small “theoretical-practical” in the end.
2. Recursion introduces us to stack discipline and how stack frames are actually stacked. Here we implement the theory we have studied so far. Fully practical.
3. Parameter Passing improves our understanding of reference and returns by one step. It lays the foundation without which you can’t understand how complex value are returned. Fully practical.
4. How returns are managed? is the final boss. Fully practical.

For the time being, practical means that we are going to study an implementation of a set of concepts that feel superficial. We can definitely use GDB to inspect the real stack in the memory but to me, it is not the right way to understand.

• To me, the right approach is that you study the theory, you implement it on paper (in terms of loose ideas) and then you move towards ultimate practicality.
• Right now, we are exploring the first two parts in this process. But very soon we will explore the third one as well.