diff options
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/mod.rs | 22 | ||||
| -rw-r--r-- | tests/ui/moves/move-fn-self-receiver.stderr | 2 |
2 files changed, 22 insertions, 2 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs index 08c2a690b30..5f28500389d 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mod.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs @@ -11,7 +11,7 @@ use rustc_hir::def::{CtorKind, Namespace}; use rustc_hir::CoroutineKind; use rustc_index::IndexSlice; use rustc_infer::infer::BoundRegionConversionTime; -use rustc_infer::traits::{FulfillmentErrorCode, SelectionError, TraitEngineExt}; +use rustc_infer::traits::{FulfillmentErrorCode, SelectionError, TraitEngine, TraitEngineExt}; use rustc_middle::mir::tcx::PlaceTy; use rustc_middle::mir::{ AggregateKind, CallSource, ConstOperand, FakeReadCause, Local, LocalInfo, LocalKind, Location, @@ -1211,7 +1211,27 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { .collect::<Vec<_>>(); fulfill_cx .register_predicate_obligations(self.infcx, obligations); + // We also register the parent obligation for the type at hand + // implementing `Clone`, to account for bounds that also need + // to be evaluated, like ensuring that `Self: Clone`. + let trait_ref = ty::TraitRef::new(tcx, clone_trait, [ty]); + let obligation = Obligation::new( + tcx, + ObligationCause::dummy(), + self.param_env, + trait_ref, + ); + fulfill_cx + .register_predicate_obligation(self.infcx, obligation); let errors = fulfill_cx.select_all_or_error(self.infcx); + // We remove the last predicate failure, which corresponds to + // the top-level obligation, because most of the type we only + // care about the other ones, *except* when it is the only one. + // This seems to only be relevant for arbitrary self-types. + // Look at `tests/ui/moves/move-fn-self-receiver.rs`. + let errors = match &errors[..] { + errors @ [] | errors @ [_] | [errors @ .., _] => errors, + }; let msg = match &errors[..] { [] => "you can `clone` the value and consume it, but this \ might not be your desired behavior" diff --git a/tests/ui/moves/move-fn-self-receiver.stderr b/tests/ui/moves/move-fn-self-receiver.stderr index 0abfcd112ef..462deacbe8d 100644 --- a/tests/ui/moves/move-fn-self-receiver.stderr +++ b/tests/ui/moves/move-fn-self-receiver.stderr @@ -55,7 +55,7 @@ note: `Foo::use_box_self` takes ownership of the receiver `self`, which moves `b | LL | fn use_box_self(self: Box<Self>) {} | ^^^^ -help: you can `clone` the value and consume it, but this might not be your desired behavior +help: you could `clone` the value and consume it, if the `Box<Foo>: Clone` trait bound could be satisfied | LL | boxed_foo.clone().use_box_self(); | ++++++++ |