There are various efforts on this, from many teams. There's AST dump, AST-based graphs, GraphRAG w/ AST grounding, embeddings based AST trimming, search based AST trimming, ctags, and so on. We're still in the exploration space, and "best practices" are still being discovered.

It's funny that everyone says that "LLMs" have plateaued, yet the base models have caught up with early attempts to build harnesses with the things I've mentioned above. They now match or exceed the previous generation software glue, with just "tools", even with limited ones like just "terminal".