Assembly output too complicated

Question

This is a probably a very basic question, please bear with me.

I'm starting to get into reverse engineering following this pdf I found online: https://beginners.re/
I am, however, stuck at the very basic steps.

The relevant part from the PDF:

When I try to compile my c++ code (which is the same as in the book) with the following command:

gcc main.cpp -S -O

This is the output I get:

2

Which, as you can see, is very different, and a lot more complicated than the supposed output written in the pdf. I'm unsure what I'm doing wrong, could anyone help me?

Answer 1

Both outputs show the same effective assembly code. In both outputs, there is only a single instruction:

ret

The second example output is a variation of ret the reason for which is listed in this answer on Stackoverflow.

The more complicated output has several code organizational assembler directives. These directives are not instructions.