From 4547b622d8d29df964fa2914213088b148c498fc Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:18:32 +0200 Subject: Merging upstream version 1.67.1+dfsg1. Signed-off-by: Daniel Baumann --- .../rustc_trait_selection/src/traits/project.rs | 577 +++++++++++---------- 1 file changed, 309 insertions(+), 268 deletions(-) (limited to 'compiler/rustc_trait_selection/src/traits/project.rs') diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index e4284b9d3..5789754e4 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -11,8 +11,8 @@ use super::Selection; use super::SelectionContext; use super::SelectionError; use super::{ - ImplSourceClosureData, ImplSourceDiscriminantKindData, ImplSourceFnPointerData, - ImplSourceGeneratorData, ImplSourcePointeeData, ImplSourceUserDefinedData, + ImplSourceClosureData, ImplSourceFnPointerData, ImplSourceFutureData, ImplSourceGeneratorData, + ImplSourceUserDefinedData, }; use super::{Normalized, NormalizedTy, ProjectionCacheEntry, ProjectionCacheKey}; @@ -27,7 +27,9 @@ use rustc_errors::ErrorGuaranteed; use rustc_hir::def::DefKind; use rustc_hir::def_id::DefId; use rustc_hir::lang_items::LangItem; +use rustc_infer::infer::at::At; use rustc_infer::infer::resolve::OpportunisticRegionResolver; +use rustc_infer::traits::ImplSourceBuiltinData; use rustc_middle::traits::select::OverflowError; use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable}; use rustc_middle::ty::visit::{MaxUniverse, TypeVisitable}; @@ -47,6 +49,23 @@ pub type ProjectionTyObligation<'tcx> = Obligation<'tcx, ty::ProjectionTy<'tcx>> pub(super) struct InProgress; +pub trait NormalizeExt<'tcx> { + /// Normalize a value using the `AssocTypeNormalizer`. + /// + /// This normalization should be used when the type contains inference variables or the + /// projection may be fallible. + fn normalize>(&self, t: T) -> InferOk<'tcx, T>; +} + +impl<'tcx> NormalizeExt<'tcx> for At<'_, 'tcx> { + fn normalize>(&self, value: T) -> InferOk<'tcx, T> { + let mut selcx = SelectionContext::new(self.infcx); + let Normalized { value, obligations } = + normalize_with_depth(&mut selcx, self.param_env, self.cause.clone(), 0, value); + InferOk { value, obligations } + } +} + /// When attempting to resolve `::Name` ... #[derive(Debug)] pub enum ProjectionError<'tcx> { @@ -193,14 +212,14 @@ pub(super) fn poly_project_and_unify_type<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &PolyProjectionObligation<'tcx>, ) -> ProjectAndUnifyResult<'tcx> { - let infcx = selcx.infcx(); + let infcx = selcx.infcx; let r = infcx.commit_if_ok(|_snapshot| { let old_universe = infcx.universe(); let placeholder_predicate = infcx.replace_bound_vars_with_placeholders(obligation.predicate); let new_universe = infcx.universe(); - let placeholder_obligation = obligation.with(placeholder_predicate); + let placeholder_obligation = obligation.with(infcx.tcx, placeholder_predicate); match project_and_unify_type(selcx, &placeholder_obligation) { ProjectAndUnifyResult::MismatchedProjectionTypes(e) => Err(e), ProjectAndUnifyResult::Holds(obligations) @@ -249,7 +268,7 @@ fn project_and_unify_type<'cx, 'tcx>( ) -> ProjectAndUnifyResult<'tcx> { let mut obligations = vec![]; - let infcx = selcx.infcx(); + let infcx = selcx.infcx; let normalized = match opt_normalize_projection_type( selcx, obligation.param_env, @@ -268,7 +287,7 @@ fn project_and_unify_type<'cx, 'tcx>( // This allows users to omit re-mentioning all bounds on an associated type and just use an // `impl Trait` for the assoc type to add more bounds. let InferOk { value: actual, obligations: new } = - selcx.infcx().replace_opaque_types_with_inference_vars( + selcx.infcx.replace_opaque_types_with_inference_vars( actual, obligation.cause.body_id, obligation.cause.span, @@ -288,39 +307,8 @@ fn project_and_unify_type<'cx, 'tcx>( } } -/// Normalizes any associated type projections in `value`, replacing -/// them with a fully resolved type where possible. The return value -/// combines the normalized result and any additional obligations that -/// were incurred as result. -pub fn normalize<'a, 'b, 'tcx, T>( - selcx: &'a mut SelectionContext<'b, 'tcx>, - param_env: ty::ParamEnv<'tcx>, - cause: ObligationCause<'tcx>, - value: T, -) -> Normalized<'tcx, T> -where - T: TypeFoldable<'tcx>, -{ - let mut obligations = Vec::new(); - let value = normalize_to(selcx, param_env, cause, value, &mut obligations); - Normalized { value, obligations } -} - -pub fn normalize_to<'a, 'b, 'tcx, T>( - selcx: &'a mut SelectionContext<'b, 'tcx>, - param_env: ty::ParamEnv<'tcx>, - cause: ObligationCause<'tcx>, - value: T, - obligations: &mut Vec>, -) -> T -where - T: TypeFoldable<'tcx>, -{ - normalize_with_depth_to(selcx, param_env, cause, 0, value, obligations) -} - /// As `normalize`, but with a custom depth. -pub fn normalize_with_depth<'a, 'b, 'tcx, T>( +pub(crate) fn normalize_with_depth<'a, 'b, 'tcx, T>( selcx: &'a mut SelectionContext<'b, 'tcx>, param_env: ty::ParamEnv<'tcx>, cause: ObligationCause<'tcx>, @@ -336,7 +324,7 @@ where } #[instrument(level = "info", skip(selcx, param_env, cause, obligations))] -pub fn normalize_with_depth_to<'a, 'b, 'tcx, T>( +pub(crate) fn normalize_with_depth_to<'a, 'b, 'tcx, T>( selcx: &'a mut SelectionContext<'b, 'tcx>, param_env: ty::ParamEnv<'tcx>, cause: ObligationCause<'tcx>, @@ -356,7 +344,7 @@ where } #[instrument(level = "info", skip(selcx, param_env, cause, obligations))] -pub fn try_normalize_with_depth_to<'a, 'b, 'tcx, T>( +pub(crate) fn try_normalize_with_depth_to<'a, 'b, 'tcx, T>( selcx: &'a mut SelectionContext<'b, 'tcx>, param_env: ty::ParamEnv<'tcx>, cause: ObligationCause<'tcx>, @@ -444,7 +432,7 @@ impl<'a, 'b, 'tcx> AssocTypeNormalizer<'a, 'b, 'tcx> { } fn fold>(&mut self, value: T) -> T { - let value = self.selcx.infcx().resolve_vars_if_possible(value); + let value = self.selcx.infcx.resolve_vars_if_possible(value); debug!(?value); assert!( @@ -516,13 +504,12 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> { Reveal::All => { let recursion_limit = self.tcx().recursion_limit(); if !recursion_limit.value_within_limit(self.depth) { - let obligation = Obligation::with_depth( - self.cause.clone(), - recursion_limit.0, - self.param_env, - ty, + self.selcx.infcx.err_ctxt().report_overflow_error( + &ty, + self.cause.span, + true, + |_| {}, ); - self.selcx.infcx().err_ctxt().report_overflow_error(&obligation, true); } let substs = substs.fold_with(self); @@ -588,7 +575,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> { // want to figure out how to register obligations with escaping vars // or handle this some other way. - let infcx = self.selcx.infcx(); + let infcx = self.selcx.infcx; let (data, mapped_regions, mapped_types, mapped_consts) = BoundVarReplacer::replace_bound_vars(infcx, &mut self.universes, data); let data = data.fold_with(self); @@ -632,13 +619,13 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> { #[instrument(skip(self), level = "debug")] fn fold_const(&mut self, constant: ty::Const<'tcx>) -> ty::Const<'tcx> { let tcx = self.selcx.tcx(); - if tcx.lazy_normalization() { + if tcx.lazy_normalization() || !needs_normalization(&constant, self.param_env.reveal()) { constant } else { let constant = constant.super_fold_with(self); debug!(?constant, ?self.param_env); with_replaced_escaping_bound_vars( - self.selcx.infcx(), + self.selcx.infcx, &mut self.universes, constant, |constant| constant.eval(tcx, self.param_env), @@ -816,9 +803,7 @@ impl<'tcx> TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> { let universe = self.universe_for(debruijn); let p = ty::PlaceholderConst { universe, name: bound_const }; self.mapped_consts.insert(p, bound_const); - self.infcx - .tcx - .mk_const(ty::ConstS { kind: ty::ConstKind::Placeholder(p), ty: ct.ty() }) + self.infcx.tcx.mk_const(p, ct.ty()) } _ => ct.super_fold_with(self), } @@ -829,7 +814,7 @@ impl<'tcx> TypeFolder<'tcx> for BoundVarReplacer<'_, 'tcx> { } } -// The inverse of `BoundVarReplacer`: replaces placeholders with the bound vars from which they came. +/// The inverse of [`BoundVarReplacer`]: replaces placeholders with the bound vars from which they came. pub struct PlaceholderReplacer<'me, 'tcx> { infcx: &'me InferCtxt<'tcx>, mapped_regions: BTreeMap, @@ -953,10 +938,7 @@ impl<'tcx> TypeFolder<'tcx> for PlaceholderReplacer<'_, 'tcx> { let db = ty::DebruijnIndex::from_usize( self.universe_indices.len() - index + self.current_index.as_usize() - 1, ); - self.tcx().mk_const(ty::ConstS { - kind: ty::ConstKind::Bound(db, *replace_var), - ty: ct.ty(), - }) + self.tcx().mk_const(ty::ConstKind::Bound(db, *replace_var), ct.ty()) } None => ct, } @@ -995,10 +977,7 @@ pub fn normalize_projection_type<'a, 'b, 'tcx>( // and a deferred predicate to resolve this when more type // information is available. - selcx - .infcx() - .infer_projection(param_env, projection_ty, cause, depth + 1, obligations) - .into() + selcx.infcx.infer_projection(param_env, projection_ty, cause, depth + 1, obligations).into() }) } @@ -1021,7 +1000,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>( depth: usize, obligations: &mut Vec>, ) -> Result>, InProgress> { - let infcx = selcx.infcx(); + let infcx = selcx.infcx; // Don't use the projection cache in intercrate mode - // the `infcx` may be re-used between intercrate in non-intercrate // mode, which could lead to using incorrect cache results. @@ -1100,7 +1079,8 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>( } } - let obligation = Obligation::with_depth(cause.clone(), depth, param_env, projection_ty); + let obligation = + Obligation::with_depth(selcx.tcx(), cause.clone(), depth, param_env, projection_ty); match project(selcx, &obligation) { Ok(Projected::Progress(Progress { @@ -1112,7 +1092,7 @@ fn opt_normalize_projection_type<'a, 'b, 'tcx>( // an impl, where-clause etc) and hence we must // re-normalize it - let projected_term = selcx.infcx().resolve_vars_if_possible(projected_term); + let projected_term = selcx.infcx.resolve_vars_if_possible(projected_term); let mut result = if projected_term.has_projections() { let mut normalizer = AssocTypeNormalizer::new( @@ -1208,9 +1188,9 @@ fn normalize_to_error<'a, 'tcx>( param_env, predicate: trait_ref.without_const().to_predicate(selcx.tcx()), }; - let tcx = selcx.infcx().tcx; + let tcx = selcx.infcx.tcx; let def_id = projection_ty.item_def_id; - let new_value = selcx.infcx().next_ty_var(TypeVariableOrigin { + let new_value = selcx.infcx.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::NormalizeProjectionType, span: tcx.def_span(def_id), }); @@ -1330,11 +1310,10 @@ fn assemble_candidate_for_impl_trait_in_trait<'cx, 'tcx>( obligation.predicate.substs.truncate_to(tcx, tcx.generics_of(trait_def_id)); // FIXME(named-returns): Binders let trait_predicate = - ty::Binder::dummy(ty::TraitRef { def_id: trait_def_id, substs: trait_substs }) - .to_poly_trait_predicate(); + ty::Binder::dummy(ty::TraitRef { def_id: trait_def_id, substs: trait_substs }); - let _ = - selcx.infcx().commit_if_ok(|_| match selcx.select(&obligation.with(trait_predicate)) { + let _ = selcx.infcx.commit_if_ok(|_| { + match selcx.select(&obligation.with(tcx, trait_predicate)) { Ok(Some(super::ImplSource::UserDefined(data))) => { candidate_set.push_candidate(ProjectionCandidate::ImplTraitInTrait( ImplTraitInTraitCandidate::Impl(data), @@ -1354,7 +1333,8 @@ fn assemble_candidate_for_impl_trait_in_trait<'cx, 'tcx>( candidate_set.mark_error(e); return Err(()); } - }); + } + }); } } @@ -1437,7 +1417,7 @@ fn assemble_candidates_from_object_ty<'cx, 'tcx>( let tcx = selcx.tcx(); let self_ty = obligation.predicate.self_ty(); - let object_ty = selcx.infcx().shallow_resolve(self_ty); + let object_ty = selcx.infcx.shallow_resolve(self_ty); let data = match object_ty.kind() { ty::Dynamic(data, ..) => data, ty::Infer(ty::TyVar(_)) => { @@ -1475,10 +1455,12 @@ fn assemble_candidates_from_predicates<'cx, 'tcx>( env_predicates: impl Iterator>, potentially_unnormalized_candidates: bool, ) { - let infcx = selcx.infcx(); + let infcx = selcx.infcx; for predicate in env_predicates { let bound_predicate = predicate.kind(); - if let ty::PredicateKind::Projection(data) = predicate.kind().skip_binder() { + if let ty::PredicateKind::Clause(ty::Clause::Projection(data)) = + predicate.kind().skip_binder() + { let data = bound_predicate.rebind(data); if data.projection_def_id() != obligation.predicate.item_def_id { continue; @@ -1528,8 +1510,8 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( // If we are resolving `>::Item == Type`, // start out by selecting the predicate `T as TraitRef<...>`: let poly_trait_ref = ty::Binder::dummy(obligation.predicate.trait_ref(selcx.tcx())); - let trait_obligation = obligation.with(poly_trait_ref.to_poly_trait_predicate()); - let _ = selcx.infcx().commit_if_ok(|_| { + let trait_obligation = obligation.with(selcx.tcx(), poly_trait_ref); + let _ = selcx.infcx.commit_if_ok(|_| { let impl_source = match selcx.select(&trait_obligation) { Ok(Some(impl_source)) => impl_source, Ok(None) => { @@ -1546,6 +1528,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( let eligible = match &impl_source { super::ImplSource::Closure(_) | super::ImplSource::Generator(_) + | super::ImplSource::Future(_) | super::ImplSource::FnPointer(_) | super::ImplSource::TraitAlias(_) => true, super::ImplSource::UserDefined(impl_data) => { @@ -1586,7 +1569,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( if obligation.param_env.reveal() == Reveal::All { // NOTE(eddyb) inference variables can resolve to parameters, so // assume `poly_trait_ref` isn't monomorphic, if it contains any. - let poly_trait_ref = selcx.infcx().resolve_vars_if_possible(poly_trait_ref); + let poly_trait_ref = selcx.infcx.resolve_vars_if_possible(poly_trait_ref); !poly_trait_ref.still_further_specializable() } else { debug!( @@ -1598,128 +1581,126 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( } } } - super::ImplSource::DiscriminantKind(..) => { - // While `DiscriminantKind` is automatically implemented for every type, - // the concrete discriminant may not be known yet. - // - // Any type with multiple potential discriminant types is therefore not eligible. - let self_ty = selcx.infcx().shallow_resolve(obligation.predicate.self_ty()); - - match self_ty.kind() { - ty::Bool - | ty::Char - | ty::Int(_) - | ty::Uint(_) - | ty::Float(_) - | ty::Adt(..) - | ty::Foreign(_) - | ty::Str - | ty::Array(..) - | ty::Slice(_) - | ty::RawPtr(..) - | ty::Ref(..) - | ty::FnDef(..) - | ty::FnPtr(..) - | ty::Dynamic(..) - | ty::Closure(..) - | ty::Generator(..) - | ty::GeneratorWitness(..) - | ty::Never - | ty::Tuple(..) - // Integers and floats always have `u8` as their discriminant. - | ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(..)) => true, - - ty::Projection(..) - | ty::Opaque(..) - | ty::Param(..) - | ty::Bound(..) - | ty::Placeholder(..) - | ty::Infer(..) - | ty::Error(_) => false, - } - } - super::ImplSource::Pointee(..) => { - // While `Pointee` is automatically implemented for every type, - // the concrete metadata type may not be known yet. - // - // Any type with multiple potential metadata types is therefore not eligible. - let self_ty = selcx.infcx().shallow_resolve(obligation.predicate.self_ty()); - - let tail = selcx.tcx().struct_tail_with_normalize( - self_ty, - |ty| { - // We throw away any obligations we get from this, since we normalize - // and confirm these obligations once again during confirmation - normalize_with_depth( - selcx, - obligation.param_env, - obligation.cause.clone(), - obligation.recursion_depth + 1, - ty, - ) - .value - }, - || {}, - ); - - match tail.kind() { - ty::Bool - | ty::Char - | ty::Int(_) - | ty::Uint(_) - | ty::Float(_) - | ty::Str - | ty::Array(..) - | ty::Slice(_) - | ty::RawPtr(..) - | ty::Ref(..) - | ty::FnDef(..) - | ty::FnPtr(..) - | ty::Dynamic(..) - | ty::Closure(..) - | ty::Generator(..) - | ty::GeneratorWitness(..) - | ty::Never - // Extern types have unit metadata, according to RFC 2850 - | ty::Foreign(_) - // If returned by `struct_tail_without_normalization` this is a unit struct - // without any fields, or not a struct, and therefore is Sized. - | ty::Adt(..) - // If returned by `struct_tail_without_normalization` this is the empty tuple. - | ty::Tuple(..) - // Integers and floats are always Sized, and so have unit type metadata. - | ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(..)) => true, - - // type parameters, opaques, and unnormalized projections have pointer - // metadata if they're known (e.g. by the param_env) to be sized - ty::Param(_) | ty::Projection(..) | ty::Opaque(..) - if selcx.infcx().predicate_must_hold_modulo_regions( - &obligation.with( - ty::Binder::dummy(ty::TraitRef::new( - selcx.tcx().require_lang_item(LangItem::Sized, None), - selcx.tcx().mk_substs_trait(self_ty, &[]), - )) - .without_const() - .to_predicate(selcx.tcx()), - ), - ) => - { - true + super::ImplSource::Builtin(..) => { + // While a builtin impl may be known to exist, the associated type may not yet + // be known. Any type with multiple potential associated types is therefore + // not eligible. + let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); + + let lang_items = selcx.tcx().lang_items(); + if lang_items.discriminant_kind_trait() == Some(poly_trait_ref.def_id()) { + match self_ty.kind() { + ty::Bool + | ty::Char + | ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Adt(..) + | ty::Foreign(_) + | ty::Str + | ty::Array(..) + | ty::Slice(_) + | ty::RawPtr(..) + | ty::Ref(..) + | ty::FnDef(..) + | ty::FnPtr(..) + | ty::Dynamic(..) + | ty::Closure(..) + | ty::Generator(..) + | ty::GeneratorWitness(..) + | ty::Never + | ty::Tuple(..) + // Integers and floats always have `u8` as their discriminant. + | ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(..)) => true, + + // type parameters, opaques, and unnormalized projections have pointer + // metadata if they're known (e.g. by the param_env) to be sized + ty::Param(_) + | ty::Projection(..) + | ty::Opaque(..) + | ty::Bound(..) + | ty::Placeholder(..) + | ty::Infer(..) + | ty::Error(_) => false, } + } else if lang_items.pointee_trait() == Some(poly_trait_ref.def_id()) { + let tail = selcx.tcx().struct_tail_with_normalize( + self_ty, + |ty| { + // We throw away any obligations we get from this, since we normalize + // and confirm these obligations once again during confirmation + normalize_with_depth( + selcx, + obligation.param_env, + obligation.cause.clone(), + obligation.recursion_depth + 1, + ty, + ) + .value + }, + || {}, + ); - // FIXME(compiler-errors): are Bound and Placeholder types ever known sized? - ty::Param(_) - | ty::Projection(..) - | ty::Opaque(..) - | ty::Bound(..) - | ty::Placeholder(..) - | ty::Infer(..) - | ty::Error(_) => { - if tail.has_infer_types() { - candidate_set.mark_ambiguous(); + match tail.kind() { + ty::Bool + | ty::Char + | ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Str + | ty::Array(..) + | ty::Slice(_) + | ty::RawPtr(..) + | ty::Ref(..) + | ty::FnDef(..) + | ty::FnPtr(..) + | ty::Dynamic(..) + | ty::Closure(..) + | ty::Generator(..) + | ty::GeneratorWitness(..) + | ty::Never + // Extern types have unit metadata, according to RFC 2850 + | ty::Foreign(_) + // If returned by `struct_tail_without_normalization` this is a unit struct + // without any fields, or not a struct, and therefore is Sized. + | ty::Adt(..) + // If returned by `struct_tail_without_normalization` this is the empty tuple. + | ty::Tuple(..) + // Integers and floats are always Sized, and so have unit type metadata. + | ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(..)) => true, + + // type parameters, opaques, and unnormalized projections have pointer + // metadata if they're known (e.g. by the param_env) to be sized + ty::Param(_) | ty::Projection(..) | ty::Opaque(..) + if selcx.infcx.predicate_must_hold_modulo_regions( + &obligation.with( + selcx.tcx(), + ty::Binder::dummy( + selcx.tcx().at(obligation.cause.span()).mk_trait_ref(LangItem::Sized, [self_ty]), + ) + .without_const(), + ), + ) => + { + true + } + + // FIXME(compiler-errors): are Bound and Placeholder types ever known sized? + ty::Param(_) + | ty::Projection(..) + | ty::Opaque(..) + | ty::Bound(..) + | ty::Placeholder(..) + | ty::Infer(..) + | ty::Error(_) => { + if tail.has_infer_types() { + candidate_set.mark_ambiguous(); + } + false } - false } + } else { + bug!("unexpected builtin trait with associated type: {poly_trait_ref:?}") } } super::ImplSource::Param(..) => { @@ -1757,7 +1738,6 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( false } super::ImplSource::AutoImpl(..) - | super::ImplSource::Builtin(..) | super::ImplSource::TraitUpcasting(_) | super::ImplSource::ConstDestruct(_) => { // These traits have no associated types. @@ -1820,8 +1800,7 @@ fn confirm_candidate<'cx, 'tcx>( // when possible for this to work. See `auto-trait-projection-recursion.rs` // for a case where this matters. if progress.term.has_infer_regions() { - progress.term = - progress.term.fold_with(&mut OpportunisticRegionResolver::new(selcx.infcx())); + progress.term = progress.term.fold_with(&mut OpportunisticRegionResolver::new(selcx.infcx)); } progress } @@ -1834,16 +1813,13 @@ fn confirm_select_candidate<'cx, 'tcx>( match impl_source { super::ImplSource::UserDefined(data) => confirm_impl_candidate(selcx, obligation, data), super::ImplSource::Generator(data) => confirm_generator_candidate(selcx, obligation, data), + super::ImplSource::Future(data) => confirm_future_candidate(selcx, obligation, data), super::ImplSource::Closure(data) => confirm_closure_candidate(selcx, obligation, data), super::ImplSource::FnPointer(data) => confirm_fn_pointer_candidate(selcx, obligation, data), - super::ImplSource::DiscriminantKind(data) => { - confirm_discriminant_kind_candidate(selcx, obligation, data) - } - super::ImplSource::Pointee(data) => confirm_pointee_candidate(selcx, obligation, data), + super::ImplSource::Builtin(data) => confirm_builtin_candidate(selcx, obligation, data), super::ImplSource::Object(_) | super::ImplSource::AutoImpl(..) | super::ImplSource::Param(..) - | super::ImplSource::Builtin(..) | super::ImplSource::TraitUpcasting(_) | super::ImplSource::TraitAlias(..) | super::ImplSource::ConstDestruct(_) => { @@ -1907,74 +1883,97 @@ fn confirm_generator_candidate<'cx, 'tcx>( .with_addl_obligations(obligations) } -fn confirm_discriminant_kind_candidate<'cx, 'tcx>( +fn confirm_future_candidate<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionTyObligation<'tcx>, - _: ImplSourceDiscriminantKindData, + impl_source: ImplSourceFutureData<'tcx, PredicateObligation<'tcx>>, ) -> Progress<'tcx> { - let tcx = selcx.tcx(); + let gen_sig = impl_source.substs.as_generator().poly_sig(); + let Normalized { value: gen_sig, obligations } = normalize_with_depth( + selcx, + obligation.param_env, + obligation.cause.clone(), + obligation.recursion_depth + 1, + gen_sig, + ); - let self_ty = selcx.infcx().shallow_resolve(obligation.predicate.self_ty()); - // We get here from `poly_project_and_unify_type` which replaces bound vars - // with placeholders - debug_assert!(!self_ty.has_escaping_bound_vars()); - let substs = tcx.mk_substs([self_ty.into()].iter()); + debug!(?obligation, ?gen_sig, ?obligations, "confirm_future_candidate"); - let discriminant_def_id = tcx.require_lang_item(LangItem::Discriminant, None); + let tcx = selcx.tcx(); + let fut_def_id = tcx.require_lang_item(LangItem::Future, None); - let predicate = ty::ProjectionPredicate { - projection_ty: ty::ProjectionTy { substs, item_def_id: discriminant_def_id }, - term: self_ty.discriminant_ty(tcx).into(), - }; + let predicate = super::util::future_trait_ref_and_outputs( + tcx, + fut_def_id, + obligation.predicate.self_ty(), + gen_sig, + ) + .map_bound(|(trait_ref, return_ty)| { + debug_assert_eq!(tcx.associated_item(obligation.predicate.item_def_id).name, sym::Output); - // We get here from `poly_project_and_unify_type` which replaces bound vars - // with placeholders, so dummy is okay here. - confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false) + ty::ProjectionPredicate { + projection_ty: ty::ProjectionTy { + substs: trait_ref.substs, + item_def_id: obligation.predicate.item_def_id, + }, + term: return_ty.into(), + } + }); + + confirm_param_env_candidate(selcx, obligation, predicate, false) + .with_addl_obligations(impl_source.nested) + .with_addl_obligations(obligations) } -fn confirm_pointee_candidate<'cx, 'tcx>( +fn confirm_builtin_candidate<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionTyObligation<'tcx>, - _: ImplSourcePointeeData, + data: ImplSourceBuiltinData>, ) -> Progress<'tcx> { let tcx = selcx.tcx(); - let self_ty = selcx.infcx().shallow_resolve(obligation.predicate.self_ty()); - - let mut obligations = vec![]; - let (metadata_ty, check_is_sized) = self_ty.ptr_metadata_ty(tcx, |ty| { - normalize_with_depth_to( - selcx, - obligation.param_env, - obligation.cause.clone(), - obligation.recursion_depth + 1, - ty, - &mut obligations, - ) - }); - if check_is_sized { - let sized_predicate = ty::Binder::dummy(ty::TraitRef::new( - tcx.require_lang_item(LangItem::Sized, None), - tcx.mk_substs_trait(self_ty, &[]), - )) - .without_const() - .to_predicate(tcx); - obligations.push(Obligation::new( - obligation.cause.clone(), - obligation.param_env, - sized_predicate, - )); - } - + let self_ty = obligation.predicate.self_ty(); let substs = tcx.mk_substs([self_ty.into()].iter()); - let metadata_def_id = tcx.require_lang_item(LangItem::Metadata, None); - - let predicate = ty::ProjectionPredicate { - projection_ty: ty::ProjectionTy { substs, item_def_id: metadata_def_id }, - term: metadata_ty.into(), + let lang_items = tcx.lang_items(); + let item_def_id = obligation.predicate.item_def_id; + let trait_def_id = tcx.trait_of_item(item_def_id).unwrap(); + let (term, obligations) = if lang_items.discriminant_kind_trait() == Some(trait_def_id) { + let discriminant_def_id = tcx.require_lang_item(LangItem::Discriminant, None); + assert_eq!(discriminant_def_id, item_def_id); + + (self_ty.discriminant_ty(tcx).into(), Vec::new()) + } else if lang_items.pointee_trait() == Some(trait_def_id) { + let metadata_def_id = tcx.require_lang_item(LangItem::Metadata, None); + assert_eq!(metadata_def_id, item_def_id); + + let mut obligations = Vec::new(); + let (metadata_ty, check_is_sized) = self_ty.ptr_metadata_ty(tcx, |ty| { + normalize_with_depth_to( + selcx, + obligation.param_env, + obligation.cause.clone(), + obligation.recursion_depth + 1, + ty, + &mut obligations, + ) + }); + if check_is_sized { + let sized_predicate = ty::Binder::dummy( + tcx.at(obligation.cause.span()).mk_trait_ref(LangItem::Sized, [self_ty]), + ) + .without_const(); + obligations.push(obligation.with(tcx, sized_predicate)); + } + (metadata_ty.into(), obligations) + } else { + bug!("unexpected builtin trait with associated type: {:?}", obligation.predicate); }; + let predicate = + ty::ProjectionPredicate { projection_ty: ty::ProjectionTy { substs, item_def_id }, term }; + confirm_param_env_candidate(selcx, obligation, ty::Binder::dummy(predicate), false) .with_addl_obligations(obligations) + .with_addl_obligations(data.nested) } fn confirm_fn_pointer_candidate<'cx, 'tcx>( @@ -1982,7 +1981,7 @@ fn confirm_fn_pointer_candidate<'cx, 'tcx>( obligation: &ProjectionTyObligation<'tcx>, fn_pointer_impl_source: ImplSourceFnPointerData<'tcx, PredicateObligation<'tcx>>, ) -> Progress<'tcx> { - let fn_type = selcx.infcx().shallow_resolve(fn_pointer_impl_source.fn_ty); + let fn_type = selcx.infcx.shallow_resolve(fn_pointer_impl_source.fn_ty); let sig = fn_type.fn_sig(selcx.tcx()); let Normalized { value: sig, obligations } = normalize_with_depth( selcx, @@ -2055,7 +2054,7 @@ fn confirm_param_env_candidate<'cx, 'tcx>( poly_cache_entry: ty::PolyProjectionPredicate<'tcx>, potentially_unnormalized_candidate: bool, ) -> Progress<'tcx> { - let infcx = selcx.infcx(); + let infcx = selcx.infcx; let cause = &obligation.cause; let param_env = obligation.param_env; @@ -2150,7 +2149,7 @@ fn confirm_impl_candidate<'cx, 'tcx>( // * `substs` ends up as `[u32, S]` let substs = obligation.predicate.substs.rebase_onto(tcx, trait_def_id, substs); let substs = - translate_substs(selcx.infcx(), param_env, impl_def_id, substs, assoc_ty.defining_node); + translate_substs(selcx.infcx, param_env, impl_def_id, substs, assoc_ty.defining_node); let ty = tcx.bound_type_of(assoc_ty.item.def_id); let is_const = matches!(tcx.def_kind(assoc_ty.item.def_id), DefKind::AssocConst); let term: ty::EarlyBinder> = if is_const { @@ -2158,7 +2157,7 @@ fn confirm_impl_candidate<'cx, 'tcx>( crate::traits::InternalSubsts::identity_for_item(tcx, assoc_ty.item.def_id); let did = ty::WithOptConstParam::unknown(assoc_ty.item.def_id); let kind = ty::ConstKind::Unevaluated(ty::UnevaluatedConst::new(did, identity_substs)); - ty.map_bound(|ty| tcx.mk_const(ty::ConstS { ty, kind }).into()) + ty.map_bound(|ty| tcx.mk_const(kind, ty).into()) } else { ty.map_bound(|ty| ty.into()) }; @@ -2177,7 +2176,7 @@ fn confirm_impl_candidate<'cx, 'tcx>( // Verify that the trait item and its implementation have compatible substs lists fn check_substs_compatible<'tcx>( tcx: TyCtxt<'tcx>, - assoc_ty: &ty::AssocItem, + assoc_item: &ty::AssocItem, substs: ty::SubstsRef<'tcx>, ) -> bool { fn check_substs_compatible_inner<'tcx>( @@ -2209,7 +2208,10 @@ fn check_substs_compatible<'tcx>( true } - check_substs_compatible_inner(tcx, tcx.generics_of(assoc_ty.def_id), substs.as_slice()) + let generics = tcx.generics_of(assoc_item.def_id); + // Chop off any additional substs (RPITIT) substs + let substs = &substs[0..generics.count().min(substs.len())]; + check_substs_compatible_inner(tcx, generics, substs) } fn confirm_impl_trait_in_trait_candidate<'tcx>( @@ -2238,11 +2240,27 @@ fn confirm_impl_trait_in_trait_candidate<'tcx>( }; } - let impl_fn_def_id = leaf_def.item.def_id; // Rebase from {trait}::{fn}::{opaque} to {impl}::{fn}::{opaque}, // since `data.substs` are the impl substs. let impl_fn_substs = obligation.predicate.substs.rebase_onto(tcx, tcx.parent(trait_fn_def_id), data.substs); + let impl_fn_substs = translate_substs( + selcx.infcx, + obligation.param_env, + data.impl_def_id, + impl_fn_substs, + leaf_def.defining_node, + ); + + if !check_substs_compatible(tcx, &leaf_def.item, impl_fn_substs) { + let err = tcx.ty_error_with_message( + obligation.cause.span, + "impl method and trait method have different parameters", + ); + return Progress { term: err.into(), obligations }; + } + + let impl_fn_def_id = leaf_def.item.def_id; let cause = ObligationCause::new( obligation.cause.span, @@ -2260,6 +2278,7 @@ fn confirm_impl_trait_in_trait_candidate<'tcx>( obligations.extend(std::iter::zip(predicates.predicates, predicates.spans).map( |(pred, span)| { Obligation::with_depth( + tcx, ObligationCause::new( obligation.cause.span, obligation.cause.body_id, @@ -2276,10 +2295,11 @@ fn confirm_impl_trait_in_trait_candidate<'tcx>( }, )); - let ty = super::normalize_to( + let ty = normalize_with_depth_to( selcx, obligation.param_env, cause.clone(), + obligation.recursion_depth + 1, tcx.bound_trait_impl_trait_tys(impl_fn_def_id) .map_bound(|tys| { tys.map_or_else(|_| tcx.ty_error(), |tys| tys[&obligation.predicate.item_def_id]) @@ -2299,11 +2319,10 @@ fn assoc_ty_own_obligations<'cx, 'tcx>( nested: &mut Vec>, ) { let tcx = selcx.tcx(); - for predicate in tcx + let own = tcx .predicates_of(obligation.predicate.item_def_id) - .instantiate_own(tcx, obligation.predicate.substs) - .predicates - { + .instantiate_own(tcx, obligation.predicate.substs); + for (predicate, span) in std::iter::zip(own.predicates, own.spans) { let normalized = normalize_with_depth_to( selcx, obligation.param_env, @@ -2312,8 +2331,30 @@ fn assoc_ty_own_obligations<'cx, 'tcx>( predicate, nested, ); + + let nested_cause = if matches!( + obligation.cause.code(), + super::CompareImplItemObligation { .. } + | super::CheckAssociatedTypeBounds { .. } + | super::AscribeUserTypeProvePredicate(..) + ) { + obligation.cause.clone() + } else if span.is_dummy() { + ObligationCause::new( + obligation.cause.span, + obligation.cause.body_id, + super::ItemObligation(obligation.predicate.item_def_id), + ) + } else { + ObligationCause::new( + obligation.cause.span, + obligation.cause.body_id, + super::BindingObligation(obligation.predicate.item_def_id, span), + ) + }; nested.push(Obligation::with_depth( - obligation.cause.clone(), + tcx, + nested_cause, obligation.recursion_depth + 1, obligation.param_env, normalized, @@ -2385,7 +2426,7 @@ impl<'cx, 'tcx> ProjectionCacheKeyExt<'cx, 'tcx> for ProjectionCacheKey<'tcx> { selcx: &mut SelectionContext<'cx, 'tcx>, predicate: ty::PolyProjectionPredicate<'tcx>, ) -> Option { - let infcx = selcx.infcx(); + let infcx = selcx.infcx; // We don't do cross-snapshot caching of obligations with escaping regions, // so there's no cache key to use predicate.no_bound_vars().map(|predicate| { -- cgit v1.2.3