How are dependencies between files handled, on startup?

[gco-bmx]

I'm reading the codebase trying to understand and get a high level view of the steps, that occur for analysis

on start up it seems like all files are parsed in parallel,
design units added to root,
then analysis also starts in a parallelized way,
it doesn't seem to be ordered based on dependencies, since before analysis it appears to not be aware of what they are
so how does it work?

possible ways I guess could be
-the analysis of a file blocks when it tries to get something from another file that hasn't been analyzed yet,
-the dependence gets completely or partially analyzed, when it tries to be looked up

is it something like this or am I way off?

[Schottkyc137]

I will preface this by saying that I don't know exactly how this is solved as I didn't write the code. However, I can make a well-educated guess:

Before doing the parallel analysis step, vhdl_lang will add each file to the DesignRoot.
For each DesignUnit, this will create an un-analyzed LockedUnit that is associated with its library. This ensures that every unit is present in the dependency graph.
A LockedUnit generally is just a wrapper around a DesignUnit (i.e., an entity, package, architecture, ...) but locked by a thread-safe RwLock so that reading is shared, but writing requires exclusive access.

This is the first step and it causes all libraries and design units to be visible. The next step is to correctly deal with dependencies between different design units (i.e., the case where the analysis of one design unit depends on that of another).

Most of this is facilitated through the Scope, and especially the lookup method.
Then the actual dependency resolution is what you described in your second point. If a dependent named entity is required, this will simply analyse that dependency. You can see examples when getting an architecture from it's name, or looking up an element in a library (notice the call to DesignRoot::get_analysis in both of these functions).

Does this answer your question? Again, please take this with a grain of salt as I didn't write any of the code that deals with dependencies - so there might be some mistakes / oversights.

[gco-bmx]

Thanks, I think this will give me enough to find the details