The building block view shall have an appropriate place for every piece of source code. In other words:
There shall be an architecture building block for every single line of source code that is created specifically for that system.
You might defer infrastructure tools (like specific build systems, code generators or similar stuff) to section 8 (crosscutting concepts) - but it’s often a good idea to at least mention them on level-1 of the building block view.
This is the only call-for-completeness we ever propose for documentation (as completeness is otherwise overly expensive to achieve - and you should not strive for completeness in anything else)
See the following diagram for an example:
Code Generator (shaded in yellow color in the lower left corner)
generates another architectural building block („Campaign Data Management“).