diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs index 3e4c194147f9..285288e87ee0 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs @@ -1932,25 +1932,96 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { None, ); } else { + let mut suggest_derive = true; if let Some(errors) = self.type_implements_trait_shallow(clone_trait_did, expected_ty, self.param_env) { + let manually_impl = "consider manually implementing `Clone` to avoid the \ + implict type parameter bounds"; match &errors[..] { [] => {} [error] => { - diag.help(format!( - "`Clone` is not implemented because the trait bound `{}` is \ - not satisfied", - error.obligation.predicate, - )); + // diag.note("{error:#?}"); + // diag.note(format!("{:#?} {:#?} {:#?}", error.obligation, error.obligation.cause, error.obligation.cause.code())); + let msg = "`Clone` is not implemented because a trait bound is not \ + satisfied"; + if let traits::ObligationCauseCode::ImplDerived(data) = + error.obligation.cause.code() + { + let mut span: MultiSpan = data.span.into(); + if self.tcx.is_automatically_derived(data.impl_or_alias_def_id) { + span.push_span_label( + data.span, + format!( + "derive introduces an implicit `{}` bound", + error.obligation.predicate + ), + ); + } + diag.span_help(span, msg); + if self.tcx.is_automatically_derived(data.impl_or_alias_def_id) + && data.impl_or_alias_def_id.is_local() + { + diag.help(manually_impl); + suggest_derive = false; + } + } else { + diag.help(msg); + } } _ => { - diag.help(format!( - "`Clone` is not implemented because the following trait bounds \ - could not be satisfied: {}", - listify(&errors, |e| format!("`{}`", e.obligation.predicate)) - .unwrap(), - )); + let unsatisfied_bounds: Vec<_> = errors + .iter() + .filter_map(|error| match error.obligation.cause.code() { + traits::ObligationCauseCode::ImplDerived(data) => { + let pre = if self + .tcx + .is_automatically_derived(data.impl_or_alias_def_id) + { + "derive introduces an implicit " + } else { + "" + }; + Some(( + data.span, + format!( + "{pre}unsatisfied trait bound `{}`", + error.obligation.predicate + ), + )) + } + _ => None, + }) + .collect(); + let msg = "`Clone` is not implemented because the some trait bounds \ + could not be satisfied"; + if errors.len() == unsatisfied_bounds.len() { + let mut unsatisfied_bounds_spans: MultiSpan = unsatisfied_bounds + .iter() + .map(|(span, _)| *span) + .collect::>() + .into(); + for (span, label) in unsatisfied_bounds { + unsatisfied_bounds_spans.push_span_label(span, label); + } + diag.span_help(unsatisfied_bounds_spans, msg); + if errors.iter().all(|error| match error.obligation.cause.code() { + traits::ObligationCauseCode::ImplDerived(data) => { + self.tcx.is_automatically_derived(data.impl_or_alias_def_id) + && data.impl_or_alias_def_id.is_local() + } + _ => false, + }) { + diag.help(manually_impl); + suggest_derive = false; + } + } else { + diag.help(format!( + "{msg}: {}", + listify(&errors, |e| format!("`{}`", e.obligation.predicate)) + .unwrap(), + )); + } } } for error in errors { @@ -1968,7 +2039,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } } } - self.suggest_derive(diag, &vec![(trait_ref.upcast(self.tcx), None, None)]); + if suggest_derive { + self.suggest_derive(diag, &vec![(trait_ref.upcast(self.tcx), None, None)]); + } } } } diff --git a/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.current.stderr b/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.current.stderr index 301f3c3a458d..5de99cc6ca6a 100644 --- a/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.current.stderr +++ b/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.current.stderr @@ -13,7 +13,8 @@ note: `HashSet` does not implement `Clone`, so `&HashSet` was cloned i | LL | let mut x: HashSet = v.clone(); | ^ - = help: `Clone` is not implemented because the trait bound `Day: Clone` is not satisfied +help: `Clone` is not implemented because a trait bound is not satisfied + --> $SRC_DIR/std/src/collections/hash/set.rs:LL:COL help: consider annotating `Day` with `#[derive(Clone)]` | LL + #[derive(Clone)] diff --git a/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.next.stderr b/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.next.stderr index 301f3c3a458d..5de99cc6ca6a 100644 --- a/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.next.stderr +++ b/tests/ui/moves/assignment-of-clone-call-on-ref-due-to-missing-bound.next.stderr @@ -13,7 +13,8 @@ note: `HashSet` does not implement `Clone`, so `&HashSet` was cloned i | LL | let mut x: HashSet = v.clone(); | ^ - = help: `Clone` is not implemented because the trait bound `Day: Clone` is not satisfied +help: `Clone` is not implemented because a trait bound is not satisfied + --> $SRC_DIR/std/src/collections/hash/set.rs:LL:COL help: consider annotating `Day` with `#[derive(Clone)]` | LL + #[derive(Clone)] diff --git a/tests/ui/traits/derive-implicit-bound-on-clone.rs b/tests/ui/traits/derive-implicit-bound-on-clone.rs new file mode 100644 index 000000000000..a4c9e88ef576 --- /dev/null +++ b/tests/ui/traits/derive-implicit-bound-on-clone.rs @@ -0,0 +1,24 @@ +// Issue #146515 +use std::rc::Rc; + +#[derive(Clone)] +struct ContainsRc { //~ HELP `Clone` is not implemented + value: Rc<(T, K)>, +} + +fn clone_me(x: &ContainsRc) -> ContainsRc { + x.clone() //~ ERROR E0308 + //~^ HELP consider manually implementing `Clone` +} + +#[derive(Clone)] +struct ContainsRcSingle { //~ HELP `Clone` is not implemented + value: Rc, +} + +fn clone_me_single(x: &ContainsRcSingle) -> ContainsRcSingle { + x.clone() //~ ERROR E0308 + //~^ HELP consider manually implementing `Clone` +} + +fn main() {} diff --git a/tests/ui/traits/derive-implicit-bound-on-clone.stderr b/tests/ui/traits/derive-implicit-bound-on-clone.stderr new file mode 100644 index 000000000000..0cec4ef7c609 --- /dev/null +++ b/tests/ui/traits/derive-implicit-bound-on-clone.stderr @@ -0,0 +1,53 @@ +error[E0308]: mismatched types + --> $DIR/derive-implicit-bound-on-clone.rs:10:5 + | +LL | fn clone_me(x: &ContainsRc) -> ContainsRc { + | ---------------- expected `ContainsRc` because of return type +LL | x.clone() + | ^^^^^^^^^ expected `ContainsRc`, found `&ContainsRc` + | + = note: expected struct `ContainsRc<_, _>` + found reference `&ContainsRc<_, _>` +note: `ContainsRc` does not implement `Clone`, so `&ContainsRc` was cloned instead + --> $DIR/derive-implicit-bound-on-clone.rs:10:5 + | +LL | x.clone() + | ^ +help: `Clone` is not implemented because the some trait bounds could not be satisfied + --> $DIR/derive-implicit-bound-on-clone.rs:5:19 + | +LL | #[derive(Clone)] + | ----- in this derive macro expansion +LL | struct ContainsRc { + | ^ ^ derive introduces an implicit unsatisfied trait bound `K: Clone` + | | + | derive introduces an implicit unsatisfied trait bound `T: Clone` + = help: consider manually implementing `Clone` to avoid the implict type parameter bounds + +error[E0308]: mismatched types + --> $DIR/derive-implicit-bound-on-clone.rs:20:5 + | +LL | fn clone_me_single(x: &ContainsRcSingle) -> ContainsRcSingle { + | ------------------- expected `ContainsRcSingle` because of return type +LL | x.clone() + | ^^^^^^^^^ expected `ContainsRcSingle`, found `&ContainsRcSingle` + | + = note: expected struct `ContainsRcSingle<_>` + found reference `&ContainsRcSingle<_>` +note: `ContainsRcSingle` does not implement `Clone`, so `&ContainsRcSingle` was cloned instead + --> $DIR/derive-implicit-bound-on-clone.rs:20:5 + | +LL | x.clone() + | ^ +help: `Clone` is not implemented because a trait bound is not satisfied + --> $DIR/derive-implicit-bound-on-clone.rs:15:25 + | +LL | #[derive(Clone)] + | ----- in this derive macro expansion +LL | struct ContainsRcSingle { + | ^ derive introduces an implicit `T: Clone` bound + = help: consider manually implementing `Clone` to avoid the implict type parameter bounds + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0308`.