diff options
| author | bors <bors@rust-lang.org> | 2024-12-12 21:40:39 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2024-12-12 21:40:39 +0000 |
| commit | 915e7eb9b9c4194887feb91626b9844e2152abb5 (patch) | |
| tree | 3538a2a65b6e413c681a0060e67e0feba917cca4 /compiler/rustc_middle | |
| parent | d4025ee454169fbd22f5773f54348310ab6a47bb (diff) | |
| parent | 337af8a37014a476d8deb081c3f209c7d56d5171 (diff) | |
Auto merge of #132961 - adetaylor:arbitrary-self-types-the-big-bit, r=compiler-errors,wesleywiser
Arbitrary self types v2: main compiler changes This is the main PR in a series of PRs related to Arbitrary Self Types v2, tracked in #44874. Specifically this is step 7 of the plan [described here](https://github.com/rust-lang/rust/issues/44874#issuecomment-2122179688), for [RFC 3519](https://github.com/rust-lang/rfcs/pull/3519). Overall this PR: * Switches from the `Deref` trait to the new `Receiver` trait when the unstable `arbitrary_self_types` feature is enabled (the simple bit) * Introduces new algorithms to spot "shadowing"; that is, the case where a newly-added method in an outer smart pointer might end up overriding a pre-existing method in the pointee (the complex bit). Most of this bit was explored in [this earlier perf-testing PR](https://github.com/rust-lang/rust/pull/127812#issuecomment-2236911900). * Lots of tests This should not break compatibility for: * Stable users, where it should have no effect * Users of the existing `arbitrary_self_types` feature (because we implement `Receiver` for `T: Deref`) _unless_ those folks have added methods which may shadow methods in inner types, which we no longer want to allow Subsequent PRs will add better diagnostics. It's probably easiest to review this commit-by-commit. r? `@wesleywiser`
Diffstat (limited to 'compiler/rustc_middle')
| -rw-r--r-- | compiler/rustc_middle/src/traits/query.rs | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/compiler/rustc_middle/src/traits/query.rs b/compiler/rustc_middle/src/traits/query.rs index eeed5118592..f049da95f29 100644 --- a/compiler/rustc_middle/src/traits/query.rs +++ b/compiler/rustc_middle/src/traits/query.rs @@ -149,11 +149,21 @@ pub struct CandidateStep<'tcx> { /// `foo.by_raw_ptr()` will work and `foo.by_ref()` won't. pub from_unsafe_deref: bool, pub unsize: bool, + /// We will generate CandidateSteps which are reachable via a chain + /// of following `Receiver`. The first 'n' of those will be reachable + /// by following a chain of 'Deref' instead (since there's a blanket + /// implementation of Receiver for Deref). + /// We use the entire set of steps when identifying method candidates + /// (e.g. identifying relevant `impl` blocks) but only those that are + /// reachable via Deref when examining what the receiver type can + /// be converted into by autodereffing. + pub reachable_via_deref: bool, } #[derive(Copy, Clone, Debug, HashStable)] pub struct MethodAutoderefStepsResult<'tcx> { - /// The valid autoderef steps that could be found. + /// The valid autoderef steps that could be found by following a chain + /// of `Receiver<Target=T>` or `Deref<Target=T>` trait implementations. pub steps: &'tcx [CandidateStep<'tcx>], /// If Some(T), a type autoderef reported an error on. pub opt_bad_ty: Option<&'tcx MethodAutoderefBadTy<'tcx>>, |