callgraph

Interactive call-graph reports for one function of the Qdrant workspace, viewable in a browser: pan/zoom graph, per-node docs and source snippets, exact call sites, GitHub/editor links.

bash

tools/callgraph/callgraph.py read_bytes_async                        # by name
tools/callgraph/callgraph.py universal_io::traits::read_bytes_async  # :: segments disambiguate
tools/callgraph/callgraph.py lib/common/common/src/universal_io/traits/read.rs:113

Prints a file://…/target/callgraph/<fn>.html link when done. Requires rust-analyzer and graphviz dot on PATH; no Python dependencies.

How it works

rust-analyzer's call hierarchy over LSP provides resolved (not textual) caller/callee edges; both directions are collected in one run.
Trait declarations and their impls are bridged via goto-implementation / goto-declaration, so a walk doesn't dead-end when a call dispatches through a trait (dashed edges in the graph).
Test code is excluded for real: rust-analyzer runs with cfg(test) off, and tests/, benches/, examples/ targets are filtered by path.
Layout by graphviz at generation time; the report itself is one self-contained HTML file with no external resources.

Options

--depth N — call hops from the root (default 4)
--max-nodes N — per-view node cap (default 250)
--out PATH — output HTML path

Performance note

Each run cold-starts rust-analyzer, which re-indexes the workspace (~3 min). If runs become frequent, the upgrade path is a --serve mode that keeps one rust-analyzer instance alive between reports.