[finnyspade]

I can actually help you out on this one. I spent the summer hacking on the Rust compiler for my internship. If I'm understanding the code correctly, this is the enum of elements represented in the dependency graph.

https://manishearth.github.io/rust-internals-docs/rustc/dep_...

Note that as per:

https://manishearth.github.io/rust-internals-docs/rustc/dep_...

The DepGraph that we actually care about is specialized to talk about DefIds. In rustc, DefIds are attached to the following things:

https://manishearth.github.io/rust-internals-docs/rustc/hir/...

This means dependencies are analyzed down to local variables and uses. But even beyond that it tracks things such as borrow checks, linting and more!