From 6d5170c960d1cf0ad1137bbf65e4d1c992cc21fe Mon Sep 17 00:00:00 2001 From: Camille GILLOT Date: Wed, 1 Jan 2020 19:10:11 +0100 Subject: [PATCH] Move some queries from rustc::ty to librustc_passes. --- src/librustc/ty/mod.rs | 356 +---------------------------------- src/librustc_passes/lib.rs | 3 + src/librustc_passes/ty.rs | 369 +++++++++++++++++++++++++++++++++++++ 3 files changed, 374 insertions(+), 354 deletions(-) create mode 100644 src/librustc_passes/ty.rs diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs index d1e37a4ea11..e6acb6b74dc 100644 --- a/src/librustc/ty/mod.rs +++ b/src/librustc/ty/mod.rs @@ -18,7 +18,6 @@ use crate::mir::interpret::ErrorHandled; use crate::mir::GeneratorLayout; use crate::mir::ReadOnlyBodyAndCache; -use crate::session::CrateDisambiguator; use crate::session::DataTypeKind; use crate::traits::{self, Reveal}; use crate::ty; @@ -31,7 +30,6 @@ use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::fx::FxIndexMap; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; -use rustc_data_structures::svh::Svh; use rustc_data_structures::sync::{self, par_iter, Lrc, ParallelIterator}; use rustc_hir as hir; use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res}; @@ -2423,70 +2421,6 @@ pub fn destructor(&self, tcx: TyCtxt<'tcx>) -> Option { pub fn sized_constraint(&self, tcx: TyCtxt<'tcx>) -> &'tcx [Ty<'tcx>] { tcx.adt_sized_constraint(self.did).0 } - - fn sized_constraint_for_ty(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Vec> { - let result = match ty.kind { - Bool | Char | Int(..) | Uint(..) | Float(..) | RawPtr(..) | Ref(..) | FnDef(..) - | FnPtr(_) | Array(..) | Closure(..) | Generator(..) | Never => vec![], - - Str | Dynamic(..) | Slice(_) | Foreign(..) | Error | GeneratorWitness(..) => { - // these are never sized - return the target type - vec![ty] - } - - Tuple(ref tys) => match tys.last() { - None => vec![], - Some(ty) => self.sized_constraint_for_ty(tcx, ty.expect_ty()), - }, - - Adt(adt, substs) => { - // recursive case - let adt_tys = adt.sized_constraint(tcx); - debug!("sized_constraint_for_ty({:?}) intermediate = {:?}", ty, adt_tys); - adt_tys - .iter() - .map(|ty| ty.subst(tcx, substs)) - .flat_map(|ty| self.sized_constraint_for_ty(tcx, ty)) - .collect() - } - - Projection(..) | Opaque(..) => { - // must calculate explicitly. - // FIXME: consider special-casing always-Sized projections - vec![ty] - } - - UnnormalizedProjection(..) => bug!("only used with chalk-engine"), - - Param(..) => { - // perf hack: if there is a `T: Sized` bound, then - // we know that `T` is Sized and do not need to check - // it on the impl. - - let sized_trait = match tcx.lang_items().sized_trait() { - Some(x) => x, - _ => return vec![ty], - }; - let sized_predicate = Binder::dummy(TraitRef { - def_id: sized_trait, - substs: tcx.mk_substs_trait(ty, &[]), - }) - .to_predicate(); - let predicates = tcx.predicates_of(self.did).predicates; - if predicates.iter().any(|(p, _)| *p == sized_predicate) { - vec![] - } else { - vec![ty] - } - } - - Placeholder(..) | Bound(..) | Infer(..) => { - bug!("unexpected type `{:?}` in sized_constraint_for_ty", ty) - } - }; - debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result); - result - } } impl<'tcx> FieldDef { @@ -2742,57 +2676,6 @@ pub fn opt_associated_item(self, def_id: DefId) -> Option { is_associated_item.then(|| self.associated_item(def_id)) } - fn associated_item_from_trait_item_ref( - self, - parent_def_id: DefId, - parent_vis: &hir::Visibility<'_>, - trait_item_ref: &hir::TraitItemRef, - ) -> AssocItem { - let def_id = self.hir().local_def_id(trait_item_ref.id.hir_id); - let (kind, has_self) = match trait_item_ref.kind { - hir::AssocItemKind::Const => (ty::AssocKind::Const, false), - hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self), - hir::AssocItemKind::Type => (ty::AssocKind::Type, false), - hir::AssocItemKind::OpaqueTy => bug!("only impls can have opaque types"), - }; - - AssocItem { - ident: trait_item_ref.ident, - kind, - // Visibility of trait items is inherited from their traits. - vis: Visibility::from_hir(parent_vis, trait_item_ref.id.hir_id, self), - defaultness: trait_item_ref.defaultness, - def_id, - container: TraitContainer(parent_def_id), - method_has_self_argument: has_self, - } - } - - fn associated_item_from_impl_item_ref( - self, - parent_def_id: DefId, - impl_item_ref: &hir::ImplItemRef<'_>, - ) -> AssocItem { - let def_id = self.hir().local_def_id(impl_item_ref.id.hir_id); - let (kind, has_self) = match impl_item_ref.kind { - hir::AssocItemKind::Const => (ty::AssocKind::Const, false), - hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self), - hir::AssocItemKind::Type => (ty::AssocKind::Type, false), - hir::AssocItemKind::OpaqueTy => (ty::AssocKind::OpaqueTy, false), - }; - - AssocItem { - ident: impl_item_ref.ident, - kind, - // Visibility of trait impl items doesn't matter. - vis: ty::Visibility::from_hir(&impl_item_ref.vis, impl_item_ref.id.hir_id, self), - defaultness: impl_item_ref.defaultness, - def_id, - container: ImplContainer(parent_def_id), - method_has_self_argument: has_self, - } - } - pub fn field_index(self, hir_id: hir::HirId, tables: &TypeckTables<'_>) -> usize { tables.field_indices().get(hir_id).cloned().expect("no index for a field") } @@ -3070,105 +2953,9 @@ fn next(&mut self) -> Option { } } -fn associated_item(tcx: TyCtxt<'_>, def_id: DefId) -> AssocItem { - let id = tcx.hir().as_local_hir_id(def_id).unwrap(); - let parent_id = tcx.hir().get_parent_item(id); - let parent_def_id = tcx.hir().local_def_id(parent_id); - let parent_item = tcx.hir().expect_item(parent_id); - match parent_item.kind { - hir::ItemKind::Impl(.., ref impl_item_refs) => { - if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.hir_id == id) { - let assoc_item = - tcx.associated_item_from_impl_item_ref(parent_def_id, impl_item_ref); - debug_assert_eq!(assoc_item.def_id, def_id); - return assoc_item; - } - } - - hir::ItemKind::Trait(.., ref trait_item_refs) => { - if let Some(trait_item_ref) = trait_item_refs.iter().find(|i| i.id.hir_id == id) { - let assoc_item = tcx.associated_item_from_trait_item_ref( - parent_def_id, - &parent_item.vis, - trait_item_ref, - ); - debug_assert_eq!(assoc_item.def_id, def_id); - return assoc_item; - } - } - - _ => {} - } - - span_bug!( - parent_item.span, - "unexpected parent of trait or impl item or item not found: {:?}", - parent_item.kind - ) -} - #[derive(Clone, HashStable)] pub struct AdtSizedConstraint<'tcx>(pub &'tcx [Ty<'tcx>]); -/// Calculates the `Sized` constraint. -/// -/// In fact, there are only a few options for the types in the constraint: -/// - an obviously-unsized type -/// - a type parameter or projection whose Sizedness can't be known -/// - a tuple of type parameters or projections, if there are multiple -/// such. -/// - a Error, if a type contained itself. The representability -/// check should catch this case. -fn adt_sized_constraint(tcx: TyCtxt<'_>, def_id: DefId) -> AdtSizedConstraint<'_> { - let def = tcx.adt_def(def_id); - - let result = tcx.mk_type_list( - def.variants - .iter() - .flat_map(|v| v.fields.last()) - .flat_map(|f| def.sized_constraint_for_ty(tcx, tcx.type_of(f.did))), - ); - - debug!("adt_sized_constraint: {:?} => {:?}", def, result); - - AdtSizedConstraint(result) -} - -fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] { - let id = tcx.hir().as_local_hir_id(def_id).unwrap(); - let item = tcx.hir().expect_item(id); - match item.kind { - hir::ItemKind::Trait(.., ref trait_item_refs) => tcx.arena.alloc_from_iter( - trait_item_refs - .iter() - .map(|trait_item_ref| trait_item_ref.id) - .map(|id| tcx.hir().local_def_id(id.hir_id)), - ), - hir::ItemKind::Impl(.., ref impl_item_refs) => tcx.arena.alloc_from_iter( - impl_item_refs - .iter() - .map(|impl_item_ref| impl_item_ref.id) - .map(|id| tcx.hir().local_def_id(id.hir_id)), - ), - hir::ItemKind::TraitAlias(..) => &[], - _ => span_bug!(item.span, "associated_item_def_ids: not impl or trait"), - } -} - -fn def_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span { - tcx.hir().span_if_local(def_id).unwrap() -} - -/// If the given `DefId` describes an item belonging to a trait, -/// returns the `DefId` of the trait that the trait item belongs to; -/// otherwise, returns `None`. -fn trait_of_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option { - tcx.opt_associated_item(def_id).and_then(|associated_item| match associated_item.container { - TraitContainer(def_id) => Some(def_id), - ImplContainer(_) => None, - }) -} - /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition. pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option { if let Some(hir_id) = tcx.hir().as_local_hir_id(def_id) { @@ -3181,151 +2968,12 @@ pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option { None } -/// See `ParamEnv` struct definition for details. -fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ParamEnv<'_> { - // The param_env of an impl Trait type is its defining function's param_env - if let Some(parent) = is_impl_trait_defn(tcx, def_id) { - return param_env(tcx, parent); - } - // Compute the bounds on Self and the type parameters. - - let InstantiatedPredicates { predicates } = tcx.predicates_of(def_id).instantiate_identity(tcx); - - // Finally, we have to normalize the bounds in the environment, in - // case they contain any associated type projections. This process - // can yield errors if the put in illegal associated types, like - // `::Bar` where `i32` does not implement `Foo`. We - // report these errors right here; this doesn't actually feel - // right to me, because constructing the environment feels like a - // kind of a "idempotent" action, but I'm not sure where would be - // a better place. In practice, we construct environments for - // every fn once during type checking, and we'll abort if there - // are any errors at that point, so after type checking you can be - // sure that this will succeed without errors anyway. - - let unnormalized_env = ty::ParamEnv::new( - tcx.intern_predicates(&predicates), - traits::Reveal::UserFacing, - tcx.sess.opts.debugging_opts.chalk.then_some(def_id), - ); - - let body_id = tcx.hir().as_local_hir_id(def_id).map_or(hir::DUMMY_HIR_ID, |id| { - tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id) - }); - let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id); - traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause) -} - -fn crate_disambiguator(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CrateDisambiguator { - assert_eq!(crate_num, LOCAL_CRATE); - tcx.sess.local_crate_disambiguator() -} - -fn original_crate_name(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Symbol { - assert_eq!(crate_num, LOCAL_CRATE); - tcx.crate_name.clone() -} - -fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh { - assert_eq!(crate_num, LOCAL_CRATE); - tcx.hir().crate_hash -} - -fn instance_def_size_estimate<'tcx>(tcx: TyCtxt<'tcx>, instance_def: InstanceDef<'tcx>) -> usize { - match instance_def { - InstanceDef::Item(..) | InstanceDef::DropGlue(..) => { - let mir = tcx.instance_mir(instance_def); - mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum() - } - // Estimate the size of other compiler-generated shims to be 1. - _ => 1, - } -} - -/// If `def_id` is an issue 33140 hack impl, returns its self type; otherwise, returns `None`. -/// -/// See [`ImplOverlapKind::Issue33140`] for more details. -fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option> { - debug!("issue33140_self_ty({:?})", def_id); - - let trait_ref = tcx - .impl_trait_ref(def_id) - .unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id)); - - debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref); - - let is_marker_like = tcx.impl_polarity(def_id) == ty::ImplPolarity::Positive - && tcx.associated_item_def_ids(trait_ref.def_id).is_empty(); - - // Check whether these impls would be ok for a marker trait. - if !is_marker_like { - debug!("issue33140_self_ty - not marker-like!"); - return None; - } - - // impl must be `impl Trait for dyn Marker1 + Marker2 + ...` - if trait_ref.substs.len() != 1 { - debug!("issue33140_self_ty - impl has substs!"); - return None; - } - - let predicates = tcx.predicates_of(def_id); - if predicates.parent.is_some() || !predicates.predicates.is_empty() { - debug!("issue33140_self_ty - impl has predicates {:?}!", predicates); - return None; - } - - let self_ty = trait_ref.self_ty(); - let self_ty_matches = match self_ty.kind { - ty::Dynamic(ref data, ty::ReStatic) => data.principal().is_none(), - _ => false, - }; - - if self_ty_matches { - debug!("issue33140_self_ty - MATCHES!"); - Some(self_ty) - } else { - debug!("issue33140_self_ty - non-matching self type"); - None - } -} - -/// Check if a function is async. -fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync { - let hir_id = tcx - .hir() - .as_local_hir_id(def_id) - .unwrap_or_else(|| bug!("asyncness: expected local `DefId`, got `{:?}`", def_id)); - - let node = tcx.hir().get(hir_id); - - let fn_like = hir_map::blocks::FnLikeNode::from_node(node).unwrap_or_else(|| { - bug!("asyncness: expected fn-like node but got `{:?}`", def_id); - }); - - fn_like.asyncness() -} - pub fn provide(providers: &mut ty::query::Providers<'_>) { context::provide(providers); erase_regions::provide(providers); layout::provide(providers); - *providers = ty::query::Providers { - asyncness, - associated_item, - associated_item_def_ids, - adt_sized_constraint, - def_span, - param_env, - trait_of_item, - crate_disambiguator, - original_crate_name, - crate_hash, - trait_impls_of: trait_def::trait_impls_of_provider, - instance_def_size_estimate, - issue33140_self_ty, - ..*providers - }; + *providers = + ty::query::Providers { trait_impls_of: trait_def::trait_impls_of_provider, ..*providers }; } /// A map for the local crate mapping each type to a vector of its diff --git a/src/librustc_passes/lib.rs b/src/librustc_passes/lib.rs index 65eb07b989d..8bd06465628 100644 --- a/src/librustc_passes/lib.rs +++ b/src/librustc_passes/lib.rs @@ -5,6 +5,7 @@ //! This API is completely unstable and subject to change. #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")] +#![feature(bool_to_option)] #![feature(in_band_lifetimes)] #![feature(nll)] #![feature(slice_patterns)] @@ -30,6 +31,7 @@ mod reachable; mod region; pub mod stability; +mod ty; pub fn provide(providers: &mut Providers<'_>) { check_const::provide(providers); @@ -42,4 +44,5 @@ pub fn provide(providers: &mut Providers<'_>) { reachable::provide(providers); region::provide(providers); stability::provide(providers); + ty::provide(providers); } diff --git a/src/librustc_passes/ty.rs b/src/librustc_passes/ty.rs new file mode 100644 index 00000000000..fc8beb67e4a --- /dev/null +++ b/src/librustc_passes/ty.rs @@ -0,0 +1,369 @@ +use rustc::hir::map as hir_map; +use rustc::session::CrateDisambiguator; +use rustc::traits::{self}; +use rustc::ty::subst::Subst; +use rustc::ty::{self, ToPredicate, Ty, TyCtxt}; +use rustc_data_structures::svh::Svh; +use rustc_hir as hir; +use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE}; +use rustc_span::symbol::Symbol; +use rustc_span::Span; + +fn sized_constraint_for_ty(tcx: TyCtxt<'tcx>, adtdef: &ty::AdtDef, ty: Ty<'tcx>) -> Vec> { + use ty::TyKind::*; + + let result = match ty.kind { + Bool | Char | Int(..) | Uint(..) | Float(..) | RawPtr(..) | Ref(..) | FnDef(..) + | FnPtr(_) | Array(..) | Closure(..) | Generator(..) | Never => vec![], + + Str | Dynamic(..) | Slice(_) | Foreign(..) | Error | GeneratorWitness(..) => { + // these are never sized - return the target type + vec![ty] + } + + Tuple(ref tys) => match tys.last() { + None => vec![], + Some(ty) => sized_constraint_for_ty(tcx, adtdef, ty.expect_ty()), + }, + + Adt(adt, substs) => { + // recursive case + let adt_tys = adt.sized_constraint(tcx); + debug!("sized_constraint_for_ty({:?}) intermediate = {:?}", ty, adt_tys); + adt_tys + .iter() + .map(|ty| ty.subst(tcx, substs)) + .flat_map(|ty| sized_constraint_for_ty(tcx, adtdef, ty)) + .collect() + } + + Projection(..) | Opaque(..) => { + // must calculate explicitly. + // FIXME: consider special-casing always-Sized projections + vec![ty] + } + + UnnormalizedProjection(..) => bug!("only used with chalk-engine"), + + Param(..) => { + // perf hack: if there is a `T: Sized` bound, then + // we know that `T` is Sized and do not need to check + // it on the impl. + + let sized_trait = match tcx.lang_items().sized_trait() { + Some(x) => x, + _ => return vec![ty], + }; + let sized_predicate = ty::Binder::dummy(ty::TraitRef { + def_id: sized_trait, + substs: tcx.mk_substs_trait(ty, &[]), + }) + .to_predicate(); + let predicates = tcx.predicates_of(adtdef.did).predicates; + if predicates.iter().any(|(p, _)| *p == sized_predicate) { vec![] } else { vec![ty] } + } + + Placeholder(..) | Bound(..) | Infer(..) => { + bug!("unexpected type `{:?}` in sized_constraint_for_ty", ty) + } + }; + debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result); + result +} + +fn associated_item_from_trait_item_ref( + tcx: TyCtxt<'_>, + parent_def_id: DefId, + parent_vis: &hir::Visibility<'_>, + trait_item_ref: &hir::TraitItemRef, +) -> ty::AssocItem { + let def_id = tcx.hir().local_def_id(trait_item_ref.id.hir_id); + let (kind, has_self) = match trait_item_ref.kind { + hir::AssocItemKind::Const => (ty::AssocKind::Const, false), + hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self), + hir::AssocItemKind::Type => (ty::AssocKind::Type, false), + hir::AssocItemKind::OpaqueTy => bug!("only impls can have opaque types"), + }; + + ty::AssocItem { + ident: trait_item_ref.ident, + kind, + // Visibility of trait items is inherited from their traits. + vis: ty::Visibility::from_hir(parent_vis, trait_item_ref.id.hir_id, tcx), + defaultness: trait_item_ref.defaultness, + def_id, + container: ty::TraitContainer(parent_def_id), + method_has_self_argument: has_self, + } +} + +fn associated_item_from_impl_item_ref( + tcx: TyCtxt<'_>, + parent_def_id: DefId, + impl_item_ref: &hir::ImplItemRef<'_>, +) -> ty::AssocItem { + let def_id = tcx.hir().local_def_id(impl_item_ref.id.hir_id); + let (kind, has_self) = match impl_item_ref.kind { + hir::AssocItemKind::Const => (ty::AssocKind::Const, false), + hir::AssocItemKind::Method { has_self } => (ty::AssocKind::Method, has_self), + hir::AssocItemKind::Type => (ty::AssocKind::Type, false), + hir::AssocItemKind::OpaqueTy => (ty::AssocKind::OpaqueTy, false), + }; + + ty::AssocItem { + ident: impl_item_ref.ident, + kind, + // Visibility of trait impl items doesn't matter. + vis: ty::Visibility::from_hir(&impl_item_ref.vis, impl_item_ref.id.hir_id, tcx), + defaultness: impl_item_ref.defaultness, + def_id, + container: ty::ImplContainer(parent_def_id), + method_has_self_argument: has_self, + } +} + +fn associated_item(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AssocItem { + let id = tcx.hir().as_local_hir_id(def_id).unwrap(); + let parent_id = tcx.hir().get_parent_item(id); + let parent_def_id = tcx.hir().local_def_id(parent_id); + let parent_item = tcx.hir().expect_item(parent_id); + match parent_item.kind { + hir::ItemKind::Impl(.., ref impl_item_refs) => { + if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.hir_id == id) { + let assoc_item = + associated_item_from_impl_item_ref(tcx, parent_def_id, impl_item_ref); + debug_assert_eq!(assoc_item.def_id, def_id); + return assoc_item; + } + } + + hir::ItemKind::Trait(.., ref trait_item_refs) => { + if let Some(trait_item_ref) = trait_item_refs.iter().find(|i| i.id.hir_id == id) { + let assoc_item = associated_item_from_trait_item_ref( + tcx, + parent_def_id, + &parent_item.vis, + trait_item_ref, + ); + debug_assert_eq!(assoc_item.def_id, def_id); + return assoc_item; + } + } + + _ => {} + } + + span_bug!( + parent_item.span, + "unexpected parent of trait or impl item or item not found: {:?}", + parent_item.kind + ) +} + +/// Calculates the `Sized` constraint. +/// +/// In fact, there are only a few options for the types in the constraint: +/// - an obviously-unsized type +/// - a type parameter or projection whose Sizedness can't be known +/// - a tuple of type parameters or projections, if there are multiple +/// such. +/// - a Error, if a type contained itself. The representability +/// check should catch this case. +fn adt_sized_constraint(tcx: TyCtxt<'_>, def_id: DefId) -> ty::AdtSizedConstraint<'_> { + let def = tcx.adt_def(def_id); + + let result = tcx.mk_type_list( + def.variants + .iter() + .flat_map(|v| v.fields.last()) + .flat_map(|f| sized_constraint_for_ty(tcx, def, tcx.type_of(f.did))), + ); + + debug!("adt_sized_constraint: {:?} => {:?}", def, result); + + ty::AdtSizedConstraint(result) +} + +fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] { + let id = tcx.hir().as_local_hir_id(def_id).unwrap(); + let item = tcx.hir().expect_item(id); + match item.kind { + hir::ItemKind::Trait(.., ref trait_item_refs) => tcx.arena.alloc_from_iter( + trait_item_refs + .iter() + .map(|trait_item_ref| trait_item_ref.id) + .map(|id| tcx.hir().local_def_id(id.hir_id)), + ), + hir::ItemKind::Impl(.., ref impl_item_refs) => tcx.arena.alloc_from_iter( + impl_item_refs + .iter() + .map(|impl_item_ref| impl_item_ref.id) + .map(|id| tcx.hir().local_def_id(id.hir_id)), + ), + hir::ItemKind::TraitAlias(..) => &[], + _ => span_bug!(item.span, "associated_item_def_ids: not impl or trait"), + } +} + +fn def_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span { + tcx.hir().span_if_local(def_id).unwrap() +} + +/// If the given `DefId` describes an item belonging to a trait, +/// returns the `DefId` of the trait that the trait item belongs to; +/// otherwise, returns `None`. +fn trait_of_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option { + tcx.opt_associated_item(def_id).and_then(|associated_item| match associated_item.container { + ty::TraitContainer(def_id) => Some(def_id), + ty::ImplContainer(_) => None, + }) +} + +/// See `ParamEnv` struct definition for details. +fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ParamEnv<'_> { + // The param_env of an impl Trait type is its defining function's param_env + if let Some(parent) = ty::is_impl_trait_defn(tcx, def_id) { + return param_env(tcx, parent); + } + // Compute the bounds on Self and the type parameters. + + let ty::InstantiatedPredicates { predicates } = + tcx.predicates_of(def_id).instantiate_identity(tcx); + + // Finally, we have to normalize the bounds in the environment, in + // case they contain any associated type projections. This process + // can yield errors if the put in illegal associated types, like + // `::Bar` where `i32` does not implement `Foo`. We + // report these errors right here; this doesn't actually feel + // right to me, because constructing the environment feels like a + // kind of a "idempotent" action, but I'm not sure where would be + // a better place. In practice, we construct environments for + // every fn once during type checking, and we'll abort if there + // are any errors at that point, so after type checking you can be + // sure that this will succeed without errors anyway. + + let unnormalized_env = ty::ParamEnv::new( + tcx.intern_predicates(&predicates), + traits::Reveal::UserFacing, + tcx.sess.opts.debugging_opts.chalk.then_some(def_id), + ); + + let body_id = tcx.hir().as_local_hir_id(def_id).map_or(hir::DUMMY_HIR_ID, |id| { + tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id) + }); + let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id); + traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause) +} + +fn crate_disambiguator(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CrateDisambiguator { + assert_eq!(crate_num, LOCAL_CRATE); + tcx.sess.local_crate_disambiguator() +} + +fn original_crate_name(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Symbol { + assert_eq!(crate_num, LOCAL_CRATE); + tcx.crate_name.clone() +} + +fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh { + assert_eq!(crate_num, LOCAL_CRATE); + tcx.hir().crate_hash +} + +fn instance_def_size_estimate<'tcx>( + tcx: TyCtxt<'tcx>, + instance_def: ty::InstanceDef<'tcx>, +) -> usize { + use ty::InstanceDef; + + match instance_def { + InstanceDef::Item(..) | InstanceDef::DropGlue(..) => { + let mir = tcx.instance_mir(instance_def); + mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum() + } + // Estimate the size of other compiler-generated shims to be 1. + _ => 1, + } +} + +/// If `def_id` is an issue 33140 hack impl, returns its self type; otherwise, returns `None`. +/// +/// See [`ImplOverlapKind::Issue33140`] for more details. +fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option> { + debug!("issue33140_self_ty({:?})", def_id); + + let trait_ref = tcx + .impl_trait_ref(def_id) + .unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id)); + + debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref); + + let is_marker_like = tcx.impl_polarity(def_id) == ty::ImplPolarity::Positive + && tcx.associated_item_def_ids(trait_ref.def_id).is_empty(); + + // Check whether these impls would be ok for a marker trait. + if !is_marker_like { + debug!("issue33140_self_ty - not marker-like!"); + return None; + } + + // impl must be `impl Trait for dyn Marker1 + Marker2 + ...` + if trait_ref.substs.len() != 1 { + debug!("issue33140_self_ty - impl has substs!"); + return None; + } + + let predicates = tcx.predicates_of(def_id); + if predicates.parent.is_some() || !predicates.predicates.is_empty() { + debug!("issue33140_self_ty - impl has predicates {:?}!", predicates); + return None; + } + + let self_ty = trait_ref.self_ty(); + let self_ty_matches = match self_ty.kind { + ty::Dynamic(ref data, ty::ReStatic) => data.principal().is_none(), + _ => false, + }; + + if self_ty_matches { + debug!("issue33140_self_ty - MATCHES!"); + Some(self_ty) + } else { + debug!("issue33140_self_ty - non-matching self type"); + None + } +} + +/// Check if a function is async. +fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync { + let hir_id = tcx + .hir() + .as_local_hir_id(def_id) + .unwrap_or_else(|| bug!("asyncness: expected local `DefId`, got `{:?}`", def_id)); + + let node = tcx.hir().get(hir_id); + + let fn_like = hir_map::blocks::FnLikeNode::from_node(node).unwrap_or_else(|| { + bug!("asyncness: expected fn-like node but got `{:?}`", def_id); + }); + + fn_like.asyncness() +} + +pub fn provide(providers: &mut ty::query::Providers<'_>) { + *providers = ty::query::Providers { + asyncness, + associated_item, + associated_item_def_ids, + adt_sized_constraint, + def_span, + param_env, + trait_of_item, + crate_disambiguator, + original_crate_name, + crate_hash, + instance_def_size_estimate, + issue33140_self_ty, + ..*providers + }; +} -- 2.44.0