diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
8 files changed, 90 insertions, 49 deletions
diff --git a/compiler/rustc_trait_selection/src/opaque_types.rs b/compiler/rustc_trait_selection/src/opaque_types.rs index c93ff0aa6e2..06287f00fad 100644 --- a/compiler/rustc_trait_selection/src/opaque_types.rs +++ b/compiler/rustc_trait_selection/src/opaque_types.rs @@ -5,15 +5,14 @@ use rustc_infer::infer::error_reporting::unexpected_hidden_region_diagnostic; use rustc_infer::infer::InferCtxt; use rustc_middle::ty::fold::{TypeFoldable, TypeFolder}; use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts}; -use rustc_middle::ty::{self, OpaqueTypeKey, Ty, TyCtxt}; +use rustc_middle::ty::{self, OpaqueHiddenType, OpaqueTypeKey, Ty, TyCtxt}; use rustc_span::Span; pub trait InferCtxtExt<'tcx> { fn infer_opaque_definition_from_instantiation( &self, opaque_type_key: OpaqueTypeKey<'tcx>, - instantiated_ty: Ty<'tcx>, - span: Span, + instantiated_ty: OpaqueHiddenType<'tcx>, ) -> Ty<'tcx>; } @@ -33,7 +32,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { /// purpose of this function is to do that translation. /// /// (*) C1 and C2 were introduced in the comments on - /// `constrain_opaque_type`. Read that comment for more context. + /// `register_member_constraints`. Read that comment for more context. /// /// # Parameters /// @@ -45,9 +44,12 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { fn infer_opaque_definition_from_instantiation( &self, opaque_type_key: OpaqueTypeKey<'tcx>, - instantiated_ty: Ty<'tcx>, - span: Span, + instantiated_ty: OpaqueHiddenType<'tcx>, ) -> Ty<'tcx> { + if self.is_tainted_by_errors() { + return self.tcx.ty_error(); + } + let OpaqueTypeKey { def_id, substs } = opaque_type_key; // Use substs to build up a reverse map from regions to their @@ -65,13 +67,12 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { // Convert the type from the function into a type valid outside // the function, by replacing invalid regions with 'static, // after producing an error for each of them. - let definition_ty = instantiated_ty.fold_with(&mut ReverseMapper::new( + let definition_ty = instantiated_ty.ty.fold_with(&mut ReverseMapper::new( self.tcx, - self.is_tainted_by_errors(), def_id, map, - instantiated_ty, - span, + instantiated_ty.ty, + instantiated_ty.span, )); debug!(?definition_ty); @@ -82,10 +83,6 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { struct ReverseMapper<'tcx> { tcx: TyCtxt<'tcx>, - /// If errors have already been reported in this fn, we suppress - /// our own errors because they are sometimes derivative. - tainted_by_errors: bool, - opaque_type_def_id: DefId, map: FxHashMap<GenericArg<'tcx>, GenericArg<'tcx>>, map_missing_regions_to_empty: bool, @@ -100,7 +97,6 @@ struct ReverseMapper<'tcx> { impl<'tcx> ReverseMapper<'tcx> { fn new( tcx: TyCtxt<'tcx>, - tainted_by_errors: bool, opaque_type_def_id: DefId, map: FxHashMap<GenericArg<'tcx>, GenericArg<'tcx>>, hidden_ty: Ty<'tcx>, @@ -108,7 +104,6 @@ impl<'tcx> ReverseMapper<'tcx> { ) -> Self { Self { tcx, - tainted_by_errors, opaque_type_def_id, map, map_missing_regions_to_empty: false, @@ -167,9 +162,7 @@ impl<'tcx> TypeFolder<'tcx> for ReverseMapper<'tcx> { match self.map.get(&r.into()).map(|k| k.unpack()) { Some(GenericArgKind::Lifetime(r1)) => r1, Some(u) => panic!("region mapped to unexpected kind: {:?}", u), - None if self.map_missing_regions_to_empty || self.tainted_by_errors => { - self.tcx.lifetimes.re_root_empty - } + None if self.map_missing_regions_to_empty => self.tcx.lifetimes.re_root_empty, None if generics.parent.is_some() => { if let Some(hidden_ty) = self.hidden_ty.take() { unexpected_hidden_region_diagnostic( diff --git a/compiler/rustc_trait_selection/src/traits/codegen.rs b/compiler/rustc_trait_selection/src/traits/codegen.rs index a607fb6c1b8..4b6784aee97 100644 --- a/compiler/rustc_trait_selection/src/traits/codegen.rs +++ b/compiler/rustc_trait_selection/src/traits/codegen.rs @@ -92,6 +92,12 @@ pub fn codegen_fulfill_obligation<'tcx>( }); let impl_source = drain_fulfillment_cx_or_panic(&infcx, &mut fulfill_cx, impl_source); + // There should be no opaque types during codegen, they all get revealed. + let opaque_types = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types(); + if !opaque_types.is_empty() { + bug!("{:#?}", opaque_types); + } + debug!("Cache miss: {:?} => {:?}", trait_ref, impl_source); Ok(&*tcx.arena.alloc(impl_source)) }) diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index d65b390af34..39da99ac252 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -1294,6 +1294,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { ty::Generator(..) => "generator", _ => "function", }; + let span = self.tcx.sess.source_map().guess_head_span(span); let mut err = struct_span_err!( self.tcx.sess, span, @@ -1673,6 +1674,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { )); let original_span = err.span.primary_span().unwrap(); + let original_span = self.tcx.sess.source_map().guess_head_span(original_span); let mut span = MultiSpan::from_span(original_span); let message = outer_generator diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index b61e6873571..d4ec677a0b1 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -214,10 +214,21 @@ fn project_and_unify_type<'cx, 'tcx>( Err(InProgress) => return Ok(Err(InProgress)), }; debug!(?normalized, ?obligations, "project_and_unify_type result"); - match infcx - .at(&obligation.cause, obligation.param_env) - .eq(normalized, obligation.predicate.term) - { + let actual = obligation.predicate.term; + // HACK: lazy TAIT would regress src/test/ui/impl-trait/nested-return-type2.rs, so we add + // a back-compat hack hat converts the RPITs into inference vars, just like they were before + // lazy TAIT. + // This does not affect TAITs in general, as tested in the nested-return-type-tait* tests. + let InferOk { value: actual, obligations: new } = + selcx.infcx().replace_opaque_types_with_inference_vars( + actual, + obligation.cause.body_id, + obligation.cause.span, + obligation.param_env, + ); + obligations.extend(new); + + match infcx.at(&obligation.cause, obligation.param_env).eq(normalized, actual) { Ok(InferOk { obligations: inferred_obligations, value: () }) => { obligations.extend(inferred_obligations); Ok(Ok(Some(obligations))) diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs index 0a85676f431..605c9ace5ed 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs @@ -3,7 +3,8 @@ use crate::infer::{InferCtxt, InferOk}; use crate::traits::engine::TraitEngineExt as _; use crate::traits::query::type_op::TypeOpOutput; use crate::traits::query::Fallible; -use crate::traits::{ObligationCause, TraitEngine}; +use crate::traits::TraitEngine; +use rustc_infer::infer::region_constraints::RegionConstraintData; use rustc_infer::traits::TraitEngineExt as _; use rustc_span::source_map::DUMMY_SP; @@ -31,6 +32,9 @@ where G: Fn() -> String, { type Output = R; + /// We can't do any custom error reporting for `CustomTypeOp`, so + /// we can use `!` to enforce that the implementation never provides it. + type ErrorInfo = !; /// Processes the operation and all resulting obligations, /// returning the final result along with any region constraints @@ -40,7 +44,7 @@ where info!("fully_perform({:?})", self); } - scrape_region_constraints(infcx, || (self.closure)(infcx)) + Ok(scrape_region_constraints(infcx, || (self.closure)(infcx))?.0) } } @@ -55,12 +59,11 @@ where /// Executes `op` and then scrapes out all the "old style" region /// constraints that result, creating query-region-constraints. -fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( +pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( infcx: &InferCtxt<'_, 'tcx>, op: impl FnOnce() -> Fallible<InferOk<'tcx, R>>, -) -> Fallible<TypeOpOutput<'tcx, Op>> { +) -> Fallible<(TypeOpOutput<'tcx, Op>, RegionConstraintData<'tcx>)> { let mut fulfill_cx = <dyn TraitEngine<'_>>::new(infcx.tcx); - let dummy_body_id = ObligationCause::dummy().body_id; // During NLL, we expect that nobody will register region // obligations **except** as part of a custom type op (and, at the @@ -75,7 +78,6 @@ fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( ); let InferOk { value, obligations } = infcx.commit_if_ok(|_| op())?; - debug_assert!(obligations.iter().all(|o| o.cause.body_id == dummy_body_id)); fulfill_cx.register_predicate_obligations(infcx, obligations); let errors = fulfill_cx.select_all_or_error(infcx); if !errors.is_empty() { @@ -99,12 +101,18 @@ fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( ); if region_constraints.is_empty() { - Ok(TypeOpOutput { output: value, constraints: None, canonicalized_query: None }) + Ok(( + TypeOpOutput { output: value, constraints: None, error_info: None }, + region_constraint_data, + )) } else { - Ok(TypeOpOutput { - output: value, - constraints: Some(Rc::new(region_constraints)), - canonicalized_query: None, - }) + Ok(( + TypeOpOutput { + output: value, + constraints: Some(Rc::new(region_constraints)), + error_info: None, + }, + region_constraint_data, + )) } } diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs index d662f61e2cf..1e72dd69339 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs @@ -28,6 +28,7 @@ pub use rustc_middle::traits::query::type_op::*; /// cannot be completed). pub trait TypeOp<'tcx>: Sized + fmt::Debug { type Output; + type ErrorInfo; /// Processes the operation and all resulting obligations, /// returning the final result along with any region constraints @@ -41,9 +42,8 @@ pub struct TypeOpOutput<'tcx, Op: TypeOp<'tcx>> { pub output: Op::Output, /// Any region constraints from performing the type op. pub constraints: Option<Rc<QueryRegionConstraints<'tcx>>>, - /// The canonicalized form of the query. - /// This for error reporting to be able to rerun the query. - pub canonicalized_query: Option<Canonical<'tcx, Op>>, + /// Used for error reporting to be able to rerun the query + pub error_info: Option<Op::ErrorInfo>, } /// "Query type ops" are type ops that are implemented using a @@ -119,10 +119,11 @@ where Q: QueryTypeOp<'tcx>, { type Output = Q::QueryResponse; + type ErrorInfo = Canonical<'tcx, ParamEnvAnd<'tcx, Q>>; fn fully_perform(self, infcx: &InferCtxt<'_, 'tcx>) -> Fallible<TypeOpOutput<'tcx, Self>> { let mut region_constraints = QueryRegionConstraints::default(); - let (output, canonicalized_query, mut obligations, _) = + let (output, error_info, mut obligations, _) = Q::fully_perform_into(self, infcx, &mut region_constraints)?; // Typically, instantiating NLL query results does not @@ -160,6 +161,6 @@ where let region_constraints = if region_constraints.is_empty() { None } else { Some(Rc::new(region_constraints)) }; - Ok(TypeOpOutput { output, constraints: region_constraints, canonicalized_query }) + Ok(TypeOpOutput { output, constraints: region_constraints, error_info }) } } diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index 3e7a2252318..cf472813e9e 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -256,6 +256,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { }; if obligation.predicate.skip_binder().self_ty().is_ty_var() { + debug!(ty = ?obligation.predicate.skip_binder().self_ty(), "ambiguous inference var or opaque type"); // Self is a type variable (e.g., `_: AsRef<str>`). // // This is somewhat problematic, as the current scheme can't really diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 72d156067a1..42f17721f9b 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -33,6 +33,7 @@ use rustc_middle::dep_graph::{DepKind, DepNodeIndex}; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::thir::abstract_const::NotConstEvaluatable; use rustc_middle::ty::fast_reject::{self, TreatParams}; +use rustc_middle::ty::fold::BottomUpFolder; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::relate::TypeRelation; use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef}; @@ -1313,6 +1314,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } } + #[instrument(skip(self, param_env, cache_fresh_trait_pred, dep_node), level = "debug")] fn insert_candidate_cache( &mut self, mut param_env: ty::ParamEnv<'tcx>, @@ -1353,6 +1355,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// a projection, look at the bounds of `T::Bar`, see if we can find a /// `Baz` bound. We return indexes into the list returned by /// `tcx.item_bounds` for any applicable bounds. + #[instrument(level = "debug", skip(self))] fn match_projection_obligation_against_definition_bounds( &mut self, obligation: &TraitObligation<'tcx>, @@ -1360,10 +1363,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let poly_trait_predicate = self.infcx().resolve_vars_if_possible(obligation.predicate); let placeholder_trait_predicate = self.infcx().replace_bound_vars_with_placeholders(poly_trait_predicate); - debug!( - ?placeholder_trait_predicate, - "match_projection_obligation_against_definition_bounds" - ); + debug!(?placeholder_trait_predicate); let tcx = self.infcx.tcx; let (def_id, substs) = match *placeholder_trait_predicate.trait_ref.self_ty().kind() { @@ -1414,7 +1414,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { }) .collect(); - debug!(?matching_bounds, "match_projection_obligation_against_definition_bounds"); + debug!(?matching_bounds); matching_bounds } @@ -1444,6 +1444,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { }); self.infcx .at(&obligation.cause, obligation.param_env) + .define_opaque_types(false) .sup(ty::Binder::dummy(placeholder_trait_ref), trait_bound) .map(|InferOk { obligations: _, value: () }| { // This method is called within a probe, so we can't have @@ -1506,6 +1507,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let is_match = self .infcx .at(&obligation.cause, obligation.param_env) + .define_opaque_types(false) .sup(obligation.predicate, infer_projection) .map_or(false, |InferOk { obligations, value: () }| { self.evaluate_predicates_recursively( @@ -2081,11 +2083,22 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { match self.match_impl(impl_def_id, obligation) { Ok(substs) => substs, Err(()) => { - bug!( - "Impl {:?} was matchable against {:?} but now is not", - impl_def_id, - obligation + self.infcx.tcx.sess.delay_span_bug( + obligation.cause.span, + &format!( + "Impl {:?} was matchable against {:?} but now is not", + impl_def_id, obligation + ), ); + let value = self.infcx.fresh_substs_for_item(obligation.cause.span, impl_def_id); + let err = self.tcx().ty_error(); + let value = value.fold_with(&mut BottomUpFolder { + tcx: self.tcx(), + ty_op: |_| err, + lt_op: |l| l, + ct_op: |c| c, + }); + Normalized { value, obligations: vec![] } } } } @@ -2137,6 +2150,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let InferOk { obligations, .. } = self .infcx .at(&cause, obligation.param_env) + .define_opaque_types(false) .eq(placeholder_obligation_trait_ref, impl_trait_ref) .map_err(|e| debug!("match_impl: failed eq_trait_refs due to `{}`", e))?; nested_obligations.extend(obligations); @@ -2220,6 +2234,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ) -> Result<Vec<PredicateObligation<'tcx>>, ()> { self.infcx .at(&obligation.cause, obligation.param_env) + // We don't want predicates for opaque types to just match all other types, + // if there is an obligation on the opaque type, then that obligation must be met + // opaquely. Otherwise we'd match any obligation to the opaque type and then error + // out later. + .define_opaque_types(false) .sup(obligation.predicate.to_poly_trait_ref(), poly_trait_ref) .map(|InferOk { obligations, .. }| obligations) .map_err(|_| ()) |