diff options
Diffstat (limited to 'compiler/rustc_middle/src/traits/mod.rs')
| -rw-r--r-- | compiler/rustc_middle/src/traits/mod.rs | 135 |
1 files changed, 86 insertions, 49 deletions
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs index 6cd75e087..5d0187a85 100644 --- a/compiler/rustc_middle/src/traits/mod.rs +++ b/compiler/rustc_middle/src/traits/mod.rs @@ -250,9 +250,6 @@ pub enum ObligationCauseCode<'tcx> { /// A tuple is WF only if its middle elements are `Sized`. TupleElem, - /// This is the trait reference from the given projection. - ProjectionWf(ty::AliasTy<'tcx>), - /// Must satisfy all of the where-clause predicates of the /// given item. ItemObligation(DefId), @@ -343,7 +340,8 @@ pub enum ObligationCauseCode<'tcx> { parent_code: InternedObligationCauseCode<'tcx>, }, - /// Error derived when matching traits/impls; see ObligationCause for more details + /// Error derived when checking an impl item is compatible with + /// its corresponding trait item's definition CompareImplItemObligation { impl_item_def_id: LocalDefId, trait_item_def_id: DefId, @@ -372,9 +370,6 @@ pub enum ObligationCauseCode<'tcx> { origin_expr: bool, }, - /// Constants in patterns must have `Structural` type. - ConstPatternStructural, - /// Computing common supertype in an if expression IfExpression(Box<IfExpressionCause<'tcx>>), @@ -407,9 +402,6 @@ pub enum ObligationCauseCode<'tcx> { /// `return` with an expression ReturnValue(hir::HirId), - /// Return type of this function - ReturnType, - /// Opaque return type of this function OpaqueReturnType(Option<(Ty<'tcx>, Span)>), @@ -419,10 +411,7 @@ pub enum ObligationCauseCode<'tcx> { /// #[feature(trivial_bounds)] is not enabled TrivialBound, - /// If `X` is the concrete type of an opaque type `impl Y`, then `X` must implement `Y` - OpaqueType, - - AwaitableExpr(Option<hir::HirId>), + AwaitableExpr(hir::HirId), ForLoopIterator, @@ -686,7 +675,7 @@ impl<'tcx, N> ImplSource<'tcx, N> { pub fn borrow_nested_obligations(&self) -> &[N] { match self { ImplSource::UserDefined(i) => &i.nested, - ImplSource::Param(n) | ImplSource::Builtin(_, n) => &n, + ImplSource::Param(n) | ImplSource::Builtin(_, n) => n, } } @@ -843,50 +832,31 @@ impl ObjectSafetyViolation { } } - pub fn solution(&self, err: &mut Diagnostic) { + pub fn solution(&self) -> ObjectSafetyViolationSolution { match self { ObjectSafetyViolation::SizedSelf(_) | ObjectSafetyViolation::SupertraitSelf(_) - | ObjectSafetyViolation::SupertraitNonLifetimeBinder(..) => {} + | ObjectSafetyViolation::SupertraitNonLifetimeBinder(..) => { + ObjectSafetyViolationSolution::None + } ObjectSafetyViolation::Method( name, MethodViolationCode::StaticMethod(Some((add_self_sugg, make_sized_sugg))), _, - ) => { - err.span_suggestion( - add_self_sugg.1, - format!( - "consider turning `{name}` into a method by giving it a `&self` argument" - ), - add_self_sugg.0.to_string(), - Applicability::MaybeIncorrect, - ); - err.span_suggestion( - make_sized_sugg.1, - format!( - "alternatively, consider constraining `{name}` so it does not apply to \ - trait objects" - ), - make_sized_sugg.0.to_string(), - Applicability::MaybeIncorrect, - ); - } + ) => ObjectSafetyViolationSolution::AddSelfOrMakeSized { + name: *name, + add_self_sugg: add_self_sugg.clone(), + make_sized_sugg: make_sized_sugg.clone(), + }, ObjectSafetyViolation::Method( name, MethodViolationCode::UndispatchableReceiver(Some(span)), _, - ) => { - err.span_suggestion( - *span, - format!("consider changing method `{name}`'s `self` parameter to be `&self`"), - "&Self", - Applicability::MachineApplicable, - ); - } + ) => ObjectSafetyViolationSolution::ChangeToRefSelf(*name, *span), ObjectSafetyViolation::AssocConst(name, _) | ObjectSafetyViolation::GAT(name, _) | ObjectSafetyViolation::Method(name, ..) => { - err.help(format!("consider moving `{name}` to another trait")); + ObjectSafetyViolationSolution::MoveToAnotherTrait(*name) } } } @@ -910,6 +880,60 @@ impl ObjectSafetyViolation { } } +#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)] +pub enum ObjectSafetyViolationSolution { + None, + AddSelfOrMakeSized { + name: Symbol, + add_self_sugg: (String, Span), + make_sized_sugg: (String, Span), + }, + ChangeToRefSelf(Symbol, Span), + MoveToAnotherTrait(Symbol), +} + +impl ObjectSafetyViolationSolution { + pub fn add_to(self, err: &mut Diagnostic) { + match self { + ObjectSafetyViolationSolution::None => {} + ObjectSafetyViolationSolution::AddSelfOrMakeSized { + name, + add_self_sugg, + make_sized_sugg, + } => { + err.span_suggestion( + add_self_sugg.1, + format!( + "consider turning `{name}` into a method by giving it a `&self` argument" + ), + add_self_sugg.0, + Applicability::MaybeIncorrect, + ); + err.span_suggestion( + make_sized_sugg.1, + format!( + "alternatively, consider constraining `{name}` so it does not apply to \ + trait objects" + ), + make_sized_sugg.0, + Applicability::MaybeIncorrect, + ); + } + ObjectSafetyViolationSolution::ChangeToRefSelf(name, span) => { + err.span_suggestion( + span, + format!("consider changing method `{name}`'s `self` parameter to be `&self`"), + "&Self", + Applicability::MachineApplicable, + ); + } + ObjectSafetyViolationSolution::MoveToAnotherTrait(name) => { + err.help(format!("consider moving `{name}` to another trait")); + } + } + } +} + /// Reasons a method might not be object-safe. #[derive(Clone, Debug, PartialEq, Eq, Hash, HashStable, PartialOrd, Ord)] pub enum MethodViolationCode { @@ -956,13 +980,26 @@ pub enum CodegenObligationError { FulfillmentError, } +/// Defines the treatment of opaque types in a given inference context. +/// +/// This affects both what opaques are allowed to be defined, but also whether +/// opaques are replaced with inference vars eagerly in the old solver (e.g. +/// in projection, and in the signature during function type-checking). #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, HashStable, TypeFoldable, TypeVisitable)] pub enum DefiningAnchor { - /// `DefId` of the item. + /// Define opaques which are in-scope of the `LocalDefId`. Also, eagerly + /// replace opaque types in `replace_opaque_types_with_inference_vars`. Bind(LocalDefId), - /// When opaque types are not resolved, we `Bubble` up, meaning - /// return the opaque/hidden type pair from query, for caller of query to handle it. + /// In contexts where we don't currently know what opaques are allowed to be + /// defined, such as (old solver) canonical queries, we will simply allow + /// opaques to be defined, but "bubble" them up in the canonical response or + /// otherwise treat them to be handled later. + /// + /// We do not eagerly replace opaque types in `replace_opaque_types_with_inference_vars`, + /// which may affect what predicates pass and fail in the old trait solver. Bubble, - /// Used to catch type mismatch errors when handling opaque types. + /// Do not allow any opaques to be defined. This is used to catch type mismatch + /// errors when handling opaque types, and also should be used when we would + /// otherwise reveal opaques (such as [`Reveal::All`] reveal mode). Error, } |