Exract manifest handling into its own crate

[brson]

The build-manifest tool inside rust-lang/rust is responsible for creating manifests, and the manifest module in rustup-dist is responsible for reading and validating manifests. There have already been bugs where manifests produced by the Rust build system failed to validate. It would be preferable if the code was in a single crate and shared between the two projects.

Extract manifest.rs into its own crate, then plug that crate back into rustup, and into build-manifest. Modify build-manifest to run the validate method before writing the manifest. Extract manifest-specific tests as well. Look for other code to share between them.

[pickfire]

I can help on this. Any idea how to share code between rust and rustup.rs?

[brson]

@pickfire the op seems to describe a good starting point. Since this is old, the first thing to do is probably acquaint oneself with the files mentioned in the op (I don't remember the details).

Imagine creating a single official command line tool and library for all manifest manipulation.

At this point though there may be 3rd party crates that handle manifests better than either rustup or rustboot, and one might consider whether that code could be pulled in to both our tools.

I'm not around to help on this anymore, but I hope you find someone that can guide you to improve rustup. It probably needs love.