Remove Engine by nnethercote · Pull Request #132338 · rust-lang/rust (original) (raw)

This is a standard pattern:

MyAnalysis.into_engine(tcx, body).iterate_to_fixpoint()

into_engine and iterate_to_fixpoint are always called in pairs, but sometimes with a builder-style pass_name call between them. But a builder-style interface is overkill here. This has been bugging me a for a while.

This commit:

• Merges Engine::new and Engine::iterate_to_fixpoint. This removes the need for Engine to have fields, leaving it as a trivial type that the next commit will remove.
• Renames Analysis::into_engine as Analysis::iterate_to_fixpoint, gives it an extra argument for the optional pass name, and makes it call Engine::iterate_to_fixpoint instead of Engine::new.

This turns the pattern from above into this:

MyAnalysis.iterate_to_fixpoint(tcx, body, None)

which is shorter at every call site, and there's less plumbing required to support it.