diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/thir/pattern/usefulness.rs')
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/usefulness.rs | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs index 115d34ff8..8dc9976ea 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs @@ -746,7 +746,7 @@ impl<'p, 'tcx> Witness<'p, 'tcx> { /// Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns` /// is not exhaustive enough. /// -/// NB: The partner lint for structs lives in `compiler/rustc_typeck/src/check/pat.rs`. +/// NB: The partner lint for structs lives in `compiler/rustc_hir_analysis/src/check/pat.rs`. fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>( cx: &MatchCheckCtxt<'p, 'tcx>, scrut_ty: Ty<'tcx>, @@ -754,9 +754,8 @@ fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>( hir_id: HirId, witnesses: Vec<DeconstructedPat<'p, 'tcx>>, ) { - cx.tcx.struct_span_lint_hir(NON_EXHAUSTIVE_OMITTED_PATTERNS, hir_id, sp, |build| { + cx.tcx.struct_span_lint_hir(NON_EXHAUSTIVE_OMITTED_PATTERNS, hir_id, sp, "some variants are not matched explicitly", |lint| { let joined_patterns = joined_uncovered_patterns(cx, &witnesses); - let mut lint = build.build("some variants are not matched explicitly"); lint.span_label(sp, pattern_not_covered_label(&witnesses, &joined_patterns)); lint.help( "ensure that all variants are matched explicitly by adding the suggested match arms", @@ -765,7 +764,7 @@ fn lint_non_exhaustive_omitted_patterns<'p, 'tcx>( "the matched value is of type `{}` and the `non_exhaustive_omitted_patterns` attribute was found", scrut_ty, )); - lint.emit(); + lint }); } @@ -842,7 +841,15 @@ fn is_useful<'p, 'tcx>( } } } else { - let ty = v.head().ty(); + let mut ty = v.head().ty(); + + // Opaque types can't get destructured/split, but the patterns can + // actually hint at hidden types, so we use the patterns' types instead. + if let ty::Opaque(..) = ty.kind() { + if let Some(row) = rows.first() { + ty = row.head().ty(); + } + } let is_non_exhaustive = cx.is_foreign_non_exhaustive_enum(ty); debug!("v.head: {:?}, v.span: {:?}", v.head(), v.head().span()); let pcx = &PatCtxt { cx, ty, span: v.head().span(), is_top_level, is_non_exhaustive }; @@ -878,7 +885,7 @@ fn is_useful<'p, 'tcx>( // that has the potential to trigger the `non_exhaustive_omitted_patterns` lint. // To understand the workings checkout `Constructor::split` and `SplitWildcard::new/into_ctors` if is_non_exhaustive_and_wild - // We check that the match has a wildcard pattern and that that wildcard is useful, + // We check that the match has a wildcard pattern and that wildcard is useful, // meaning there are variants that are covered by the wildcard. Without the check // for `witness_preference` the lint would trigger on `if let NonExhaustiveEnum::A = foo {}` && usefulness.is_useful() && matches!(witness_preference, RealArm) |