diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs index f0a77cb39a6..335814f8627 100644 --- a/compiler/rustc_typeck/src/check/check.rs +++ b/compiler/rustc_typeck/src/check/check.rs @@ -371,8 +371,13 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b let param_env = tcx.param_env(item_def_id); for field in fields { let field_ty = field.ty(tcx, substs); - // We are currently checking the type this field came from, so it must be local. - let field_span = tcx.hir().span_if_local(field.did).unwrap(); + let (field_span, ty_span) = + // We are currently checking the type this field came from, so it must be local. + if let Node::Field(field) = tcx.hir().get_if_local(field.did).unwrap() { + (field.span, field.ty.span) + } else { + unreachable!("mir field has to correspond to hir field"); + }; if field_ty.needs_drop(tcx, param_env) { struct_span_err!( tcx.sess, @@ -380,7 +385,11 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b E0740, "unions may not contain fields that need dropping" ) - .span_note(field_span, "`std::mem::ManuallyDrop` can be used to wrap the type") + .multipart_suggestion_verbose( + "wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped", + vec![(ty_span, format!("std::mem::ManuallyDrop<{}>", field_ty))], + Applicability::MaybeIncorrect, + ) .emit(); return false; } diff --git a/src/test/ui/feature-gates/feature-gate-untagged_unions.stderr b/src/test/ui/feature-gates/feature-gate-untagged_unions.stderr index ed973871b3f..a9ccb835587 100644 --- a/src/test/ui/feature-gates/feature-gate-untagged_unions.stderr +++ b/src/test/ui/feature-gates/feature-gate-untagged_unions.stderr @@ -13,11 +13,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: String, | ^^^^^^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/feature-gate-untagged_unions.rs:16:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: String, - | ^^^^^^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error[E0740]: unions may not contain fields that need dropping --> $DIR/feature-gate-untagged_unions.rs:24:5 @@ -25,11 +24,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: T, | ^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/feature-gate-untagged_unions.rs:24:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: T, - | ^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~ error: aborting due to 3 previous errors diff --git a/src/test/ui/union/issue-41073.stderr b/src/test/ui/union/issue-41073.stderr index 2e9598b2271..04b4286cc4b 100644 --- a/src/test/ui/union/issue-41073.stderr +++ b/src/test/ui/union/issue-41073.stderr @@ -4,11 +4,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: A, | ^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/issue-41073.rs:4:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: A, - | ^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~ error: aborting due to previous error diff --git a/src/test/ui/union/union-custom-drop.stderr b/src/test/ui/union/union-custom-drop.stderr index ee2333f905f..0c59048f7fe 100644 --- a/src/test/ui/union/union-custom-drop.stderr +++ b/src/test/ui/union/union-custom-drop.stderr @@ -4,11 +4,10 @@ error[E0740]: unions may not contain fields that need dropping LL | bar: Bar, | ^^^^^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-custom-drop.rs:7:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | bar: Bar, - | ^^^^^^^^ +LL | bar: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: aborting due to previous error diff --git a/src/test/ui/union/union-with-drop-fields.mirunsafeck.stderr b/src/test/ui/union/union-with-drop-fields.mirunsafeck.stderr index 2062fb7473f..8f3d30cd7ee 100644 --- a/src/test/ui/union/union-with-drop-fields.mirunsafeck.stderr +++ b/src/test/ui/union/union-with-drop-fields.mirunsafeck.stderr @@ -4,11 +4,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: String, | ^^^^^^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-with-drop-fields.rs:11:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: String, - | ^^^^^^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error[E0740]: unions may not contain fields that need dropping --> $DIR/union-with-drop-fields.rs:19:5 @@ -16,11 +15,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: S, | ^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-with-drop-fields.rs:19:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: S, - | ^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~ error[E0740]: unions may not contain fields that need dropping --> $DIR/union-with-drop-fields.rs:24:5 @@ -28,11 +26,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: T, | ^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-with-drop-fields.rs:24:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: T, - | ^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~ error: aborting due to 3 previous errors diff --git a/src/test/ui/union/union-with-drop-fields.thirunsafeck.stderr b/src/test/ui/union/union-with-drop-fields.thirunsafeck.stderr index 2062fb7473f..8f3d30cd7ee 100644 --- a/src/test/ui/union/union-with-drop-fields.thirunsafeck.stderr +++ b/src/test/ui/union/union-with-drop-fields.thirunsafeck.stderr @@ -4,11 +4,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: String, | ^^^^^^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-with-drop-fields.rs:11:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: String, - | ^^^^^^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error[E0740]: unions may not contain fields that need dropping --> $DIR/union-with-drop-fields.rs:19:5 @@ -16,11 +15,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: S, | ^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-with-drop-fields.rs:19:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: S, - | ^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~ error[E0740]: unions may not contain fields that need dropping --> $DIR/union-with-drop-fields.rs:24:5 @@ -28,11 +26,10 @@ error[E0740]: unions may not contain fields that need dropping LL | a: T, | ^^^^ | -note: `std::mem::ManuallyDrop` can be used to wrap the type - --> $DIR/union-with-drop-fields.rs:24:5 +help: wrap the type with `std::mem::ManuallyDrop` and ensure it is manually dropped | -LL | a: T, - | ^^^^ +LL | a: std::mem::ManuallyDrop, + | ~~~~~~~~~~~~~~~~~~~~~~~~~ error: aborting due to 3 previous errors