diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_hir_typeck/src/pat.rs | 67 | ||||
| -rw-r--r-- | compiler/rustc_passes/src/check_attr.rs | 47 | ||||
| -rw-r--r-- | compiler/rustc_resolve/src/late/diagnostics.rs | 88 |
3 files changed, 153 insertions, 49 deletions
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs index ae00bb4e218..73a1432b06c 100644 --- a/compiler/rustc_hir_typeck/src/pat.rs +++ b/compiler/rustc_hir_typeck/src/pat.rs @@ -230,10 +230,19 @@ enum InheritedRefMatchRule { /// underlying type is not a reference type, the inherited reference will be consumed. EatInner, /// When the underlying type is a reference type, reference patterns consume both layers of - /// reference, i.e. they both reset the binding mode and consume the reference type. Reference - /// patterns are not permitted when there is no underlying reference type, i.e. they can't eat - /// only an inherited reference. This is the current stable Rust behavior. - EatBoth, + /// reference, i.e. they both reset the binding mode and consume the reference type. + EatBoth { + /// If `true`, an inherited reference will be considered when determining whether a reference + /// pattern matches a given type: + /// - If the underlying type is not a reference, a reference pattern may eat the inherited reference; + /// - If the underlying type is a reference, a reference pattern matches if it can eat either one + /// of the underlying and inherited references. E.g. a `&mut` pattern is allowed if either the + /// underlying type is `&mut` or the inherited reference is `&mut`. + /// If `false`, a reference pattern is only matched against the underlying type. + /// This is `false` for stable Rust and `true` for both the `ref_pat_eat_one_layer_2024` and + /// `ref_pat_eat_one_layer_2024_structural` feature gates. + consider_inherited_ref: bool, + }, } impl<'a, 'tcx> FnCtxt<'a, 'tcx> { @@ -259,10 +268,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { } else { // Currently, matching against an inherited ref on edition 2024 is an error. // Use `EatBoth` as a fallback to be similar to stable Rust. - InheritedRefMatchRule::EatBoth + InheritedRefMatchRule::EatBoth { consider_inherited_ref: false } } } else { - InheritedRefMatchRule::EatBoth + InheritedRefMatchRule::EatBoth { + consider_inherited_ref: self.tcx.features().ref_pat_eat_one_layer_2024() + || self.tcx.features().ref_pat_eat_one_layer_2024_structural(), + } } } @@ -2371,6 +2383,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // NB: This assumes that `&` patterns can match against mutable // references (RFC 3627, Rule 5). If we implement a pattern typing // ruleset with Rule 4 but not Rule 5, we'll need to check that here. + // FIXME(ref_pat_eat_one_layer_2024_structural): If we already tried + // matching the real reference, the error message should explain that + // falling back to the inherited reference didn't work. This should be + // the same error as the old-Edition version below. debug_assert!(ref_pat_matches_mut_ref); self.error_inherited_ref_mutability_mismatch(pat, pat_prefix_span); } @@ -2381,9 +2397,46 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { return expected; } } - InheritedRefMatchRule::EatBoth => { + InheritedRefMatchRule::EatBoth { consider_inherited_ref: true } => { // Reset binding mode on old editions pat_info.binding_mode = ByRef::No; + + if let ty::Ref(_, inner_ty, _) = *expected.kind() { + // Consume both the inherited and inner references. + if pat_mutbl.is_mut() && inh_mut.is_mut() { + // As a special case, a `&mut` reference pattern will be able to match + // against a reference type of any mutability if the inherited ref is + // mutable. Since this allows us to match against a shared reference + // type, we refer to this as "falling back" to matching the inherited + // reference, though we consume the real reference as well. We handle + // this here to avoid adding this case to the common logic below. + self.check_pat(inner, inner_ty, pat_info); + return expected; + } else { + // Otherwise, use the common logic below for matching the inner + // reference type. + // FIXME(ref_pat_eat_one_layer_2024_structural): If this results in a + // mutability mismatch, the error message should explain that falling + // back to the inherited reference didn't work. This should be the same + // error as the Edition 2024 version above. + } + } else { + // The expected type isn't a reference type, so only match against the + // inherited reference. + if pat_mutbl > inh_mut { + // We can't match a lone inherited shared reference with `&mut`. + self.error_inherited_ref_mutability_mismatch(pat, pat_prefix_span); + } + + self.typeck_results.borrow_mut().skipped_ref_pats_mut().insert(pat.hir_id); + self.check_pat(inner, expected, pat_info); + return expected; + } + } + InheritedRefMatchRule::EatBoth { consider_inherited_ref: false } => { + // Reset binding mode on stable Rust. This will be a type error below if + // `expected` is not a reference type. + pat_info.binding_mode = ByRef::No; self.add_rust_2024_migration_desugared_pat( pat_info.top_info.hir_id, pat, diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs index 5111a025f94..74c48a45f18 100644 --- a/compiler/rustc_passes/src/check_attr.rs +++ b/compiler/rustc_passes/src/check_attr.rs @@ -1431,37 +1431,48 @@ impl<'tcx> CheckAttrVisitor<'tcx> { /// Warns against some misuses of `#[must_use]` fn check_must_use(&self, hir_id: HirId, attr: &Attribute, target: Target) { - if !matches!( + if matches!( target, Target::Fn | Target::Enum | Target::Struct | Target::Union - | Target::Method(_) + | Target::Method(MethodKind::Trait { body: false } | MethodKind::Inherent) | Target::ForeignFn // `impl Trait` in return position can trip // `unused_must_use` if `Trait` is marked as // `#[must_use]` | Target::Trait ) { - let article = match target { - Target::ExternCrate - | Target::Enum - | Target::Impl - | Target::Expression - | Target::Arm - | Target::AssocConst - | Target::AssocTy => "an", - _ => "a", - }; + return; + } - self.tcx.emit_node_span_lint( - UNUSED_ATTRIBUTES, - hir_id, - attr.span, - errors::MustUseNoEffect { article, target }, - ); + // `#[must_use]` can be applied to a trait method definition with a default body + if let Target::Method(MethodKind::Trait { body: true }) = target + && let parent_def_id = self.tcx.hir().get_parent_item(hir_id).def_id + && let containing_item = self.tcx.hir().expect_item(parent_def_id) + && let hir::ItemKind::Trait(..) = containing_item.kind + { + return; } + + let article = match target { + Target::ExternCrate + | Target::Enum + | Target::Impl + | Target::Expression + | Target::Arm + | Target::AssocConst + | Target::AssocTy => "an", + _ => "a", + }; + + self.tcx.emit_node_span_lint( + UNUSED_ATTRIBUTES, + hir_id, + attr.span, + errors::MustUseNoEffect { article, target }, + ); } /// Checks if `#[must_not_suspend]` is applied to a struct, enum, union, or trait. diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index 0962865e7f1..b37c684a055 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -8,7 +8,7 @@ use rustc_ast::ptr::P; use rustc_ast::visit::{FnCtxt, FnKind, LifetimeCtxt, Visitor, walk_ty}; use rustc_ast::{ self as ast, AssocItemKind, DUMMY_NODE_ID, Expr, ExprKind, GenericParam, GenericParamKind, - Item, ItemKind, MethodCall, NodeId, Path, Ty, TyKind, + Item, ItemKind, MethodCall, NodeId, Path, PathSegment, Ty, TyKind, }; use rustc_ast_pretty::pprust::where_bound_predicate_to_string; use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; @@ -1529,7 +1529,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { Applicability::MaybeIncorrect, ); true - } else if kind == DefKind::Struct + } else if matches!(kind, DefKind::Struct | DefKind::TyAlias) && let Some(lhs_source_span) = lhs_span.find_ancestor_inside(expr.span) && let Ok(snippet) = this.r.tcx.sess.source_map().span_to_snippet(lhs_source_span) { @@ -1566,7 +1566,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { } }; - let mut bad_struct_syntax_suggestion = |this: &mut Self, def_id: DefId| { + let bad_struct_syntax_suggestion = |this: &mut Self, err: &mut Diag<'_>, def_id: DefId| { let (followed_by_brace, closing_brace) = this.followed_by_brace(span); match source { @@ -1740,12 +1740,10 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { } } ( - Res::Def(kind @ (DefKind::Mod | DefKind::Trait), _), + Res::Def(kind @ (DefKind::Mod | DefKind::Trait | DefKind::TyAlias), _), PathSource::Expr(Some(parent)), - ) => { - if !path_sep(self, err, parent, kind) { - return false; - } + ) if path_sep(self, err, parent, kind) => { + return true; } ( Res::Def(DefKind::Enum, def_id), @@ -1777,13 +1775,13 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { let (ctor_def, ctor_vis, fields) = if let Some(struct_ctor) = struct_ctor { if let PathSource::Expr(Some(parent)) = source { if let ExprKind::Field(..) | ExprKind::MethodCall(..) = parent.kind { - bad_struct_syntax_suggestion(self, def_id); + bad_struct_syntax_suggestion(self, err, def_id); return true; } } struct_ctor } else { - bad_struct_syntax_suggestion(self, def_id); + bad_struct_syntax_suggestion(self, err, def_id); return true; }; @@ -1861,7 +1859,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { err.span_label(span, "constructor is not visible here due to private fields"); } (Res::Def(DefKind::Union | DefKind::Variant, def_id), _) if ns == ValueNS => { - bad_struct_syntax_suggestion(self, def_id); + bad_struct_syntax_suggestion(self, err, def_id); } (Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id), _) if ns == ValueNS => { match source { @@ -2471,31 +2469,73 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { def_id: DefId, span: Span, ) { - let Some(variants) = self.collect_enum_ctors(def_id) else { + let Some(variant_ctors) = self.collect_enum_ctors(def_id) else { err.note("you might have meant to use one of the enum's variants"); return; }; - let suggest_only_tuple_variants = - matches!(source, PathSource::TupleStruct(..)) || source.is_call(); - if suggest_only_tuple_variants { + // If the expression is a field-access or method-call, try to find a variant with the field/method name + // that could have been intended, and suggest replacing the `.` with `::`. + // Otherwise, suggest adding `::VariantName` after the enum; + // and if the expression is call-like, only suggest tuple variants. + let (suggest_path_sep_dot_span, suggest_only_tuple_variants) = match source { + // `Type(a, b)` in a pattern, only suggest adding a tuple variant after `Type`. + PathSource::TupleStruct(..) => (None, true), + PathSource::Expr(Some(expr)) => match &expr.kind { + // `Type(a, b)`, only suggest adding a tuple variant after `Type`. + ExprKind::Call(..) => (None, true), + // `Type.Foo(a, b)`, suggest replacing `.` -> `::` if variant `Foo` exists and is a tuple variant, + // otherwise suggest adding a variant after `Type`. + ExprKind::MethodCall(box MethodCall { + receiver, + span, + seg: PathSegment { ident, .. }, + .. + }) => { + let dot_span = receiver.span.between(*span); + let found_tuple_variant = variant_ctors.iter().any(|(path, _, ctor_kind)| { + *ctor_kind == CtorKind::Fn + && path.segments.last().is_some_and(|seg| seg.ident == *ident) + }); + (found_tuple_variant.then_some(dot_span), false) + } + // `Type.Foo`, suggest replacing `.` -> `::` if variant `Foo` exists and is a unit or tuple variant, + // otherwise suggest adding a variant after `Type`. + ExprKind::Field(base, ident) => { + let dot_span = base.span.between(ident.span); + let found_tuple_or_unit_variant = variant_ctors.iter().any(|(path, ..)| { + path.segments.last().is_some_and(|seg| seg.ident == *ident) + }); + (found_tuple_or_unit_variant.then_some(dot_span), false) + } + _ => (None, false), + }, + _ => (None, false), + }; + + if let Some(dot_span) = suggest_path_sep_dot_span { + err.span_suggestion_verbose( + dot_span, + "use the path separator to refer to a variant", + "::", + Applicability::MaybeIncorrect, + ); + } else if suggest_only_tuple_variants { // Suggest only tuple variants regardless of whether they have fields and do not // suggest path with added parentheses. - let mut suggestable_variants = variants + let mut suggestable_variants = variant_ctors .iter() .filter(|(.., kind)| *kind == CtorKind::Fn) .map(|(variant, ..)| path_names_to_string(variant)) .collect::<Vec<_>>(); suggestable_variants.sort(); - let non_suggestable_variant_count = variants.len() - suggestable_variants.len(); + let non_suggestable_variant_count = variant_ctors.len() - suggestable_variants.len(); - let source_msg = if source.is_call() { - "to construct" - } else if matches!(source, PathSource::TupleStruct(..)) { + let source_msg = if matches!(source, PathSource::TupleStruct(..)) { "to match against" } else { - unreachable!() + "to construct" }; if !suggestable_variants.is_empty() { @@ -2514,7 +2554,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { } // If the enum has no tuple variants.. - if non_suggestable_variant_count == variants.len() { + if non_suggestable_variant_count == variant_ctors.len() { err.help(format!("the enum has no tuple variants {source_msg}")); } @@ -2537,7 +2577,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { } }; - let mut suggestable_variants = variants + let mut suggestable_variants = variant_ctors .iter() .filter(|(_, def_id, kind)| !needs_placeholder(*def_id, *kind)) .map(|(variant, _, kind)| (path_names_to_string(variant), kind)) @@ -2564,7 +2604,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> { ); } - let mut suggestable_variants_with_placeholders = variants + let mut suggestable_variants_with_placeholders = variant_ctors .iter() .filter(|(_, def_id, kind)| needs_placeholder(*def_id, *kind)) .map(|(variant, _, kind)| (path_names_to_string(variant), kind)) |