diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs index aef880acbe1be..84e986488a6a4 100644 --- a/compiler/rustc_hir_typeck/src/_match.rs +++ b/compiler/rustc_hir_typeck/src/_match.rs @@ -121,6 +121,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { prior_arm_ty, prior_arm_span, scrut_span: scrut.span, + scrut_hir_id: scrut.hir_id, source: match_src, prior_arms: other_arms.clone(), opt_suggest_box_span, diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs index fdeaf7f6850d8..97ab3d0b7517d 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs @@ -776,6 +776,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ref prior_arms, opt_suggest_box_span, scrut_span, + scrut_hir_id, .. }) => match source { hir::MatchSource::TryDesugar(scrut_hir_id) => { @@ -843,6 +844,18 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> { ) { err.subdiagnostic(subdiag); } + if let Some(hir::Node::Expr(m)) = self.tcx.hir().find_parent(scrut_hir_id) + && let Some(hir::Node::Stmt(stmt)) = self.tcx.hir().find_parent(m.hir_id) + && let hir::StmtKind::Expr(_) = stmt.kind + { + err.span_suggestion_verbose( + stmt.span.shrink_to_hi(), + "consider using a semicolon here, but this will discard any values \ + in the match arms", + ";", + Applicability::MaybeIncorrect, + ); + } if let Some(ret_sp) = opt_suggest_box_span { // Get return type span and point to it. self.suggest_boxing_for_return_impl_trait( diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs index 9397e98343e31..9e2ff3820af64 100644 --- a/compiler/rustc_middle/src/traits/mod.rs +++ b/compiler/rustc_middle/src/traits/mod.rs @@ -541,6 +541,7 @@ pub struct MatchExpressionArmCause<'tcx> { pub prior_arm_ty: Ty<'tcx>, pub prior_arm_span: Span, pub scrut_span: Span, + pub scrut_hir_id: hir::HirId, pub source: hir::MatchSource, pub prior_arms: Vec, pub opt_suggest_box_span: Option, diff --git a/tests/ui/suggestions/issue-81839.stderr b/tests/ui/suggestions/issue-81839.stderr index 6d0a0c7b3faa2..238ee637c7d4b 100644 --- a/tests/ui/suggestions/issue-81839.stderr +++ b/tests/ui/suggestions/issue-81839.stderr @@ -4,15 +4,22 @@ error[E0308]: `match` arms have incompatible types LL | / match num { LL | | 1 => { LL | | cx.answer_str("hi"); - | | -------------------- - | | | | - | | | help: consider removing this semicolon - | | this is found to be of type `()` + | | -------------------- this is found to be of type `()` LL | | } LL | | _ => cx.answer_str("hi"), | | ^^^^^^^^^^^^^^^^^^^ expected `()`, found future LL | | } | |_____- `match` arms have incompatible types + | +help: consider removing this semicolon + | +LL - cx.answer_str("hi"); +LL + cx.answer_str("hi") + | +help: consider using a semicolon here, but this will discard any values in the match arms + | +LL | }; + | + error: aborting due to previous error diff --git a/tests/ui/wf/wf-unsafe-trait-obj-match.stderr b/tests/ui/wf/wf-unsafe-trait-obj-match.stderr index 66504e440600e..d5b23572ff577 100644 --- a/tests/ui/wf/wf-unsafe-trait-obj-match.stderr +++ b/tests/ui/wf/wf-unsafe-trait-obj-match.stderr @@ -11,6 +11,10 @@ LL | | } | = note: expected reference `&S` found reference `&R` +help: consider using a semicolon here, but this will discard any values in the match arms + | +LL | }; + | + error[E0038]: the trait `Trait` cannot be made into an object --> $DIR/wf-unsafe-trait-obj-match.rs:26:21