diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src/traits/project.rs')
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/project.rs | 240 |
1 files changed, 122 insertions, 118 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 0dce504903c..99fa791b375 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -965,36 +965,38 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( let self_ty = selcx.infcx.shallow_resolve(obligation.predicate.self_ty()); let tcx = selcx.tcx(); - let lang_items = selcx.tcx().lang_items(); - if [ - lang_items.coroutine_trait(), - lang_items.future_trait(), - lang_items.iterator_trait(), - lang_items.async_iterator_trait(), - lang_items.fn_trait(), - lang_items.fn_mut_trait(), - lang_items.fn_once_trait(), - lang_items.async_fn_trait(), - lang_items.async_fn_mut_trait(), - lang_items.async_fn_once_trait(), - ] - .contains(&Some(trait_ref.def_id)) - { - true - } else if tcx.is_lang_item(trait_ref.def_id, LangItem::AsyncFnKindHelper) { - // FIXME(async_closures): Validity constraints here could be cleaned up. - if obligation.predicate.args.type_at(0).is_ty_var() - || obligation.predicate.args.type_at(4).is_ty_var() - || obligation.predicate.args.type_at(5).is_ty_var() - { - candidate_set.mark_ambiguous(); - true - } else { - obligation.predicate.args.type_at(0).to_opt_closure_kind().is_some() - && obligation.predicate.args.type_at(1).to_opt_closure_kind().is_some() + match selcx.tcx().as_lang_item(trait_ref.def_id) { + Some( + LangItem::Coroutine + | LangItem::Future + | LangItem::Iterator + | LangItem::AsyncIterator + | LangItem::Fn + | LangItem::FnMut + | LangItem::FnOnce + | LangItem::AsyncFn + | LangItem::AsyncFnMut + | LangItem::AsyncFnOnce, + ) => true, + Some(LangItem::AsyncFnKindHelper) => { + // FIXME(async_closures): Validity constraints here could be cleaned up. + if obligation.predicate.args.type_at(0).is_ty_var() + || obligation.predicate.args.type_at(4).is_ty_var() + || obligation.predicate.args.type_at(5).is_ty_var() + { + candidate_set.mark_ambiguous(); + true + } else { + obligation.predicate.args.type_at(0).to_opt_closure_kind().is_some() + && obligation + .predicate + .args + .type_at(1) + .to_opt_closure_kind() + .is_some() + } } - } else if tcx.is_lang_item(trait_ref.def_id, LangItem::DiscriminantKind) { - match self_ty.kind() { + Some(LangItem::DiscriminantKind) => match self_ty.kind() { ty::Bool | ty::Char | ty::Int(_) @@ -1031,9 +1033,8 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( | ty::Placeholder(..) | ty::Infer(..) | ty::Error(_) => false, - } - } else if tcx.is_lang_item(trait_ref.def_id, LangItem::AsyncDestruct) { - match self_ty.kind() { + }, + Some(LangItem::AsyncDestruct) => match self_ty.kind() { ty::Bool | ty::Char | ty::Int(_) @@ -1068,101 +1069,104 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( | ty::Placeholder(..) | ty::Infer(_) | ty::Error(_) => false, - } - } else if tcx.is_lang_item(trait_ref.def_id, LangItem::PointeeTrait) { - let tail = selcx.tcx().struct_tail_raw( - 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 - }, - || {}, - ); + }, + Some(LangItem::PointeeTrait) => { + let tail = selcx.tcx().struct_tail_raw( + 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::Pat(..) - | ty::Slice(_) - | ty::RawPtr(..) - | ty::Ref(..) - | ty::FnDef(..) - | ty::FnPtr(..) - | ty::Dynamic(..) - | ty::Closure(..) - | ty::CoroutineClosure(..) - | ty::Coroutine(..) - | ty::CoroutineWitness(..) - | ty::Never - // Extern types have unit metadata, according to RFC 2850 - | ty::Foreign(_) - // If returned by `struct_tail` this is a unit struct - // without any fields, or not a struct, and therefore is Sized. - | ty::Adt(..) - // If returned by `struct_tail` 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(..)) - // This happens if we reach the recursion limit when finding the struct tail. - | ty::Error(..) => true, - - // We normalize from `Wrapper<Tail>::Metadata` to `Tail::Metadata` if able. - // Otherwise, type parameters, opaques, and unnormalized projections have - // unit metadata if they're known (e.g. by the param_env) to be sized. - ty::Param(_) | ty::Alias(..) - if self_ty != tail - || selcx.infcx.predicate_must_hold_modulo_regions( - &obligation.with( - selcx.tcx(), - ty::TraitRef::new( + match tail.kind() { + ty::Bool + | ty::Char + | ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Str + | ty::Array(..) + | ty::Pat(..) + | ty::Slice(_) + | ty::RawPtr(..) + | ty::Ref(..) + | ty::FnDef(..) + | ty::FnPtr(..) + | ty::Dynamic(..) + | ty::Closure(..) + | ty::CoroutineClosure(..) + | ty::Coroutine(..) + | ty::CoroutineWitness(..) + | ty::Never + // Extern types have unit metadata, according to RFC 2850 + | ty::Foreign(_) + // If returned by `struct_tail` this is a unit struct + // without any fields, or not a struct, and therefore is Sized. + | ty::Adt(..) + // If returned by `struct_tail` 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(..)) + // This happens if we reach the recursion limit when finding the struct tail. + | ty::Error(..) => true, + + // We normalize from `Wrapper<Tail>::Metadata` to `Tail::Metadata` if able. + // Otherwise, type parameters, opaques, and unnormalized projections have + // unit metadata if they're known (e.g. by the param_env) to be sized. + ty::Param(_) | ty::Alias(..) + if self_ty != tail + || selcx.infcx.predicate_must_hold_modulo_regions( + &obligation.with( selcx.tcx(), - selcx.tcx().require_lang_item( - LangItem::Sized, - Some(obligation.cause.span), + ty::TraitRef::new( + selcx.tcx(), + selcx.tcx().require_lang_item( + LangItem::Sized, + Some(obligation.cause.span), + ), + [self_ty], ), - [self_ty], ), - ), - ) => - { - true - } + ) => + { + true + } - ty::UnsafeBinder(_) => todo!("FIXME(unsafe_binder)"), + ty::UnsafeBinder(_) => todo!("FIXME(unsafe_binder)"), - // FIXME(compiler-errors): are Bound and Placeholder types ever known sized? - ty::Param(_) - | ty::Alias(..) - | ty::Bound(..) - | ty::Placeholder(..) - | ty::Infer(..) => { - if tail.has_infer_types() { - candidate_set.mark_ambiguous(); + // FIXME(compiler-errors): are Bound and Placeholder types ever known sized? + ty::Param(_) + | ty::Alias(..) + | ty::Bound(..) + | ty::Placeholder(..) + | ty::Infer(..) => { + if tail.has_infer_types() { + candidate_set.mark_ambiguous(); + } + false } - false } } - } else if tcx.trait_is_auto(trait_ref.def_id) { - tcx.dcx().span_delayed_bug( - tcx.def_span(obligation.predicate.def_id), - "associated types not allowed on auto traits", - ); - false - } else { - bug!("unexpected builtin trait with associated type: {trait_ref:?}") + _ if tcx.trait_is_auto(trait_ref.def_id) => { + tcx.dcx().span_delayed_bug( + tcx.def_span(obligation.predicate.def_id), + "associated types not allowed on auto traits", + ); + false + } + _ => { + bug!("unexpected builtin trait with associated type: {trait_ref:?}") + } } } ImplSource::Param(..) => { |