Crate fixup_features

A quick and dirty command-line tool to enforce certain properties about Arti’s Cargo.toml files.

Definitions.

• An experimental feature is one for which we do not provide semver guarantees.
• A non-additive feature is one whose behavior does something other than add functionality to its crate. (For example, building statically or switching out a default is non-additive.)
• The meta features are default, full, experimental, __is_nonadditive, and __is_experimental.
• The toplevel features are default, full, and experimental.
• A feature A “is reachable from” some feature B if there is a nonempty path from A to B in the feature graph.
• A feature A “directly depends on” some feature B if there is an edge from A to B in the feature graph. We also say that feature B “is listed in” feature A.

The properties that we want to enforce are:

1. Every crate has a “full” feature.
2. For every crate within Arti, if we depend on that crate, our “full” includes that crate’s “full”.
3. Every feature listed in experimental depends on __is_experimental. Every feature that depends on __is_experimental is reachable from experimental. Call such features “experimental” features.
4. Call a feature “non-additive” if and only if it depends directly on __is_nonadditive. Every non-meta feature we declare is reachable from “full” or “experimental”, or it is non-additive.
5. Every feature reachable from default is reachable from full.
6. No non-additive feature is reachable from full or experimental.
7. No experimental is reachable from full.
8. No in-workspace dependency uses the * wildcard version.
9. Only unpublished crates may depend on unpublished crates.

This tool can edit Cargo.toml files to enforce the rules 1-3 automatically. For rules 4-7, it can annotate any offending features with comments complaining about how they need to be fixed. For rules 8 and 9, it generates warnings.

To use:

Run this tool with the top-level Cargo.toml as an argument. Run with --no-annotate if you don’t want any comments added.

Limitations

This is not very efficient, and is not trying to be.

Modules

changes 🔒

Remember a list of changes to a Cargo.toml file

graph 🔒

Graph manipulation code

Structs

Crate 🔒

Stored information about a crate.

CrateInfo 🔒

Information about a crate that we use in other crates.

Dependency 🔒

A dependency from a crate.

Warning 🔒

A warning we return from our linter.

Functions

arti_dependencies 🔒

Given a [dependencies] table from a Cargo.toml, find all of the dependencies that are also part of arti.

list_crate_paths 🔒

Look at a toplevel Cargo.toml and find all of the paths in workplace.members

main 🔒