Reasoning about Rust: an introduction to Rustdoc's JSON format

How do you statically analyze a Rust codebase without unstable compiler internals? Discover Rustdoc's JSON format, a stable API for building powerful developer tools.

#1about 6 minutes

Reasoning about large-scale Rust projects

Large codebases introduce challenges in governance, architecture, and security that require automated tooling beyond standard linters.

#2about 6 minutes

The limitations of macros for static analysis

Procedural macros execute at compile-time but are limited because they operate on token streams without access to type information or a reflection API.

#3about 6 minutes

Using Rustdoc's JSON format for machine-readable APIs

Rustdoc can output a versioned JSON representation of a crate's public API, providing a stable, machine-parsable format for building custom tools.

#4about 3 minutes

Practical examples of tools using Rustdoc JSON

Explore tools like cargo-semver-checks, cargo-check-external-types, and the pavex framework that leverage Rustdoc JSON for tasks like versioning and dependency injection.

#5about 3 minutes

Limitations and future outlook for Rustdoc JSON

The format is not a silver bullet as it lacks function body information, but it represents a vital first step for building advanced meta-tooling for Rust.

#6about 4 minutes

Q&A on ecosystem integration and custom metadata

Discussion covers how Rustdoc JSON integrates into the CI toolchain and the current inability to add custom metadata attributes for project-specific tooling.

#7about 10 minutes

Q&A on adoption challenges and future improvements

Common pitfalls include linking data across crates, while future improvements may include stable identifiers, stabilization, and better multi-version support.

#8about 8 minutes