From ba40fe99c3624719e8bf7f324f02ecb0d8cb7849 Mon Sep 17 00:00:00 2001 From: Camille GILLOT Date: Thu, 26 May 2022 08:59:15 +0200 Subject: [PATCH] Compute `is_late_bound` in a separate query. The computation is actually much simpler, and can be done by directly fetching the HIR for the `FnDecl` and its generics. --- .../rustc_borrowck/src/universal_regions.rs | 4 +- compiler/rustc_middle/src/hir/map/mod.rs | 6 +- compiler/rustc_middle/src/query/mod.rs | 2 +- compiler/rustc_middle/src/ty/context.rs | 7 ++ compiler/rustc_resolve/src/late/lifetimes.rs | 92 +++++-------------- compiler/rustc_typeck/src/collect.rs | 35 ++----- 6 files changed, 47 insertions(+), 99 deletions(-) diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs index 7b63ec516b8c4..c2c093f9f2fc7 100644 --- a/compiler/rustc_borrowck/src/universal_regions.rs +++ b/compiler/rustc_borrowck/src/universal_regions.rs @@ -830,11 +830,11 @@ fn for_each_late_bound_region_defined_on<'tcx>( fn_def_id: DefId, mut f: impl FnMut(ty::Region<'tcx>), ) { - if let Some((owner, late_bounds)) = tcx.is_late_bound_map(fn_def_id.expect_local()) { + if let Some(late_bounds) = tcx.is_late_bound_map(fn_def_id.expect_local()) { for ®ion_def_id in late_bounds.iter() { let name = tcx.item_name(region_def_id.to_def_id()); let liberated_region = tcx.mk_region(ty::ReFree(ty::FreeRegion { - scope: owner.to_def_id(), + scope: fn_def_id, bound_region: ty::BoundRegionKind::BrNamed(region_def_id.to_def_id(), name), })); f(liberated_region); diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs index 97f429cfd3fa6..2c40eab8764af 100644 --- a/compiler/rustc_middle/src/hir/map/mod.rs +++ b/compiler/rustc_middle/src/hir/map/mod.rs @@ -364,7 +364,11 @@ impl<'hir> Map<'hir> { match node.node { OwnerNode::ImplItem(impl_item) => Some(&impl_item.generics), OwnerNode::TraitItem(trait_item) => Some(&trait_item.generics), - OwnerNode::Item(Item { + OwnerNode::ForeignItem(ForeignItem { + kind: ForeignItemKind::Fn(_, _, generics), + .. + }) + | OwnerNode::Item(Item { kind: ItemKind::Fn(_, generics, _) | ItemKind::TyAlias(_, generics) diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs index 38d8e0b581953..899d6c7e490a6 100644 --- a/compiler/rustc_middle/src/query/mod.rs +++ b/compiler/rustc_middle/src/query/mod.rs @@ -1584,7 +1584,7 @@ rustc_queries! { Option<&'tcx FxHashMap> { desc { "looking up a named region" } } - query is_late_bound_map(_: LocalDefId) -> Option<(LocalDefId, &'tcx FxHashSet)> { + query is_late_bound_map(_: LocalDefId) -> Option<&'tcx FxHashSet> { desc { "testing if a region is late bound" } } /// For a given item (like a struct), gets the default lifetimes to be used diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index a0d92e2a5dd94..72e2beb372d3c 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -2803,6 +2803,13 @@ impl<'tcx> TyCtxt<'tcx> { self.named_region_map(id.owner).and_then(|map| map.get(&id.local_id).cloned()) } + pub fn is_late_bound(self, id: HirId) -> bool { + self.is_late_bound_map(id.owner).map_or(false, |set| { + let def_id = self.hir().local_def_id(id); + set.contains(&def_id) + }) + } + pub fn late_bound_vars(self, id: HirId) -> &'tcx List { self.mk_bound_variable_kinds( self.late_bound_vars_map(id.owner) diff --git a/compiler/rustc_resolve/src/late/lifetimes.rs b/compiler/rustc_resolve/src/late/lifetimes.rs index 6cd81aa7dac13..11f80b314d770 100644 --- a/compiler/rustc_resolve/src/late/lifetimes.rs +++ b/compiler/rustc_resolve/src/late/lifetimes.rs @@ -16,11 +16,11 @@ use rustc_hir::def_id::{DefIdMap, LocalDefId}; use rustc_hir::hir_id::ItemLocalId; use rustc_hir::intravisit::{self, Visitor}; use rustc_hir::{GenericArg, GenericParam, LifetimeName, Node}; -use rustc_hir::{GenericParamKind, HirIdMap, HirIdSet}; +use rustc_hir::{GenericParamKind, HirIdMap}; use rustc_middle::hir::map::Map; use rustc_middle::hir::nested_filter; use rustc_middle::middle::resolve_lifetime::*; -use rustc_middle::ty::{self, DefIdTree, GenericParamDefKind, TyCtxt}; +use rustc_middle::ty::{self, GenericParamDefKind, TyCtxt}; use rustc_middle::{bug, span_bug}; use rustc_span::def_id::DefId; use rustc_span::symbol::{kw, sym, Ident}; @@ -134,11 +134,6 @@ struct NamedRegionMap { // `Region` describing how that region is bound defs: HirIdMap, - // the set of lifetime def ids that are late-bound; a region can - // be late-bound if (a) it does NOT appear in a where-clause and - // (b) it DOES appear in the arguments. - late_bound: HirIdSet, - // Maps relevant hir items to the bound vars on them. These include: // - function defs // - function pointers @@ -402,7 +397,7 @@ fn resolve_lifetimes_trait_definition( tcx: TyCtxt<'_>, local_def_id: LocalDefId, ) -> ResolveLifetimes { - convert_named_region_map(tcx, do_resolve(tcx, local_def_id, true, false)) + convert_named_region_map(do_resolve(tcx, local_def_id, true, false)) } /// Computes the `ResolveLifetimes` map that contains data for an entire `Item`. @@ -410,7 +405,7 @@ fn resolve_lifetimes_trait_definition( /// `named_region_map`, `is_late_bound_map`, etc. #[tracing::instrument(level = "debug", skip(tcx))] fn resolve_lifetimes(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> ResolveLifetimes { - convert_named_region_map(tcx, do_resolve(tcx, local_def_id, false, false)) + convert_named_region_map(do_resolve(tcx, local_def_id, false, false)) } fn do_resolve( @@ -422,7 +417,6 @@ fn do_resolve( let item = tcx.hir().expect_item(local_def_id); let mut named_region_map = NamedRegionMap { defs: Default::default(), - late_bound: Default::default(), late_bound_vars: Default::default(), scope_for_path: with_scope_for_path.then(|| Default::default()), }; @@ -439,18 +433,13 @@ fn do_resolve( named_region_map } -fn convert_named_region_map(tcx: TyCtxt<'_>, named_region_map: NamedRegionMap) -> ResolveLifetimes { +fn convert_named_region_map(named_region_map: NamedRegionMap) -> ResolveLifetimes { let mut rl = ResolveLifetimes::default(); for (hir_id, v) in named_region_map.defs { let map = rl.defs.entry(hir_id.owner).or_default(); map.insert(hir_id.local_id, v); } - for hir_id in named_region_map.late_bound { - let map = rl.late_bound.entry(hir_id.owner).or_default(); - let def_id = tcx.hir().local_def_id(hir_id); - map.insert(def_id); - } for (hir_id, v) in named_region_map.late_bound_vars { let map = rl.late_bound_vars.entry(hir_id.owner).or_default(); map.insert(hir_id.local_id, v); @@ -506,28 +495,6 @@ fn item_for(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> LocalDefId { item } -fn is_late_bound_map<'tcx>( - tcx: TyCtxt<'tcx>, - def_id: LocalDefId, -) -> Option<(LocalDefId, &'tcx FxHashSet)> { - match tcx.def_kind(def_id) { - DefKind::AnonConst | DefKind::InlineConst => { - let mut def_id = tcx.local_parent(def_id); - // We search for the next outer anon const or fn here - // while skipping closures. - // - // Note that for `AnonConst` we still just recurse until we - // find a function body, but who cares :shrug: - while tcx.is_closure(def_id.to_def_id()) { - def_id = tcx.local_parent(def_id); - } - - tcx.is_late_bound_map(def_id) - } - _ => resolve_lifetimes_for(tcx, def_id).late_bound.get(&def_id).map(|lt| (def_id, lt)), - } -} - /// In traits, there is an implicit `Self` type parameter which comes before the generics. /// We have to account for this when computing the index of the other generic parameters. /// This function returns whether there is such an implicit parameter defined on the given item. @@ -687,9 +654,9 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> { _ => {} } match item.kind { - hir::ItemKind::Fn(ref sig, ref generics, _) => { + hir::ItemKind::Fn(_, ref generics, _) => { self.missing_named_lifetime_spots.push(generics.into()); - self.visit_early_late(None, item.hir_id(), &sig.decl, generics, |this| { + self.visit_early_late(None, item.hir_id(), generics, |this| { intravisit::walk_item(this, item); }); self.missing_named_lifetime_spots.pop(); @@ -731,13 +698,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> { self.map.defs.insert(hir::HirId { owner, local_id }, *region); }); } - for (&owner, late_bound) in resolved_lifetimes.late_bound.iter() { - late_bound.iter().for_each(|&id| { - let hir_id = self.tcx.local_def_id_to_hir_id(id); - debug_assert_eq!(owner, hir_id.owner); - self.map.late_bound.insert(hir_id); - }); - } for (&owner, late_bound_vars) in resolved_lifetimes.late_bound_vars.iter() { @@ -807,8 +767,8 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> { fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) { match item.kind { - hir::ForeignItemKind::Fn(ref decl, _, ref generics) => { - self.visit_early_late(None, item.hir_id(), decl, generics, |this| { + hir::ForeignItemKind::Fn(_, _, ref generics) => { + self.visit_early_late(None, item.hir_id(), generics, |this| { intravisit::walk_foreign_item(this, item); }) } @@ -1085,13 +1045,12 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> { fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) { use self::hir::TraitItemKind::*; match trait_item.kind { - Fn(ref sig, _) => { + Fn(_, _) => { self.missing_named_lifetime_spots.push((&trait_item.generics).into()); let tcx = self.tcx; self.visit_early_late( Some(tcx.hir().get_parent_item(trait_item.hir_id())), trait_item.hir_id(), - &sig.decl, &trait_item.generics, |this| intravisit::walk_trait_item(this, trait_item), ); @@ -1153,13 +1112,12 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> { fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) { use self::hir::ImplItemKind::*; match impl_item.kind { - Fn(ref sig, _) => { + Fn(..) => { self.missing_named_lifetime_spots.push((&impl_item.generics).into()); let tcx = self.tcx; self.visit_early_late( Some(tcx.hir().get_parent_item(impl_item.hir_id())), impl_item.hir_id(), - &sig.decl, &impl_item.generics, |this| intravisit::walk_impl_item(this, impl_item), ); @@ -1656,14 +1614,11 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { &mut self, parent_id: Option, hir_id: hir::HirId, - decl: &'tcx hir::FnDecl<'tcx>, generics: &'tcx hir::Generics<'tcx>, walk: F, ) where F: for<'b, 'c> FnOnce(&'b mut LifetimeContext<'c, 'tcx>), { - insert_late_bound_lifetimes(self.tcx, self.map, decl, generics); - // Find the start of nested early scopes, e.g., in methods. let mut next_early_index = 0; if let Some(parent_id) = parent_id { @@ -1687,7 +1642,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { .iter() .filter_map(|param| match param.kind { GenericParamKind::Lifetime { .. } => { - if self.map.late_bound.contains(¶m.hir_id) { + if self.tcx.is_late_bound(param.hir_id) { let late_bound_idx = named_late_bound_vars; named_late_bound_vars += 1; Some(Region::late(late_bound_idx, self.tcx.hir(), param)) @@ -1708,7 +1663,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { .iter() .filter(|param| { matches!(param.kind, GenericParamKind::Lifetime { .. }) - && self.map.late_bound.contains(¶m.hir_id) + && self.tcx.is_late_bound(param.hir_id) }) .enumerate() .map(|(late_bound_idx, param)| { @@ -2613,7 +2568,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { } /// Detects late-bound lifetimes and inserts them into -/// `map.late_bound`. +/// `late_bound`. /// /// A region declared on a fn is **late-bound** if: /// - it is constrained by an argument type; @@ -2622,13 +2577,13 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> { /// "Constrained" basically means that it appears in any type but /// not amongst the inputs to a projection. In other words, `<&'a /// T as Trait<''b>>::Foo` does not constrain `'a` or `'b`. -#[tracing::instrument(level = "debug", skip(tcx, map))] -fn insert_late_bound_lifetimes( - tcx: TyCtxt<'_>, - map: &mut NamedRegionMap, - decl: &hir::FnDecl<'_>, - generics: &hir::Generics<'_>, -) { +fn is_late_bound_map(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<&FxHashSet> { + let hir_id = tcx.hir().local_def_id_to_hir_id(def_id); + let decl = tcx.hir().fn_decl_by_hir_id(hir_id)?; + let generics = tcx.hir().get_generics(def_id)?; + + let mut late_bound = FxHashSet::default(); + let mut constrained_by_input = ConstrainedCollector::default(); for arg_ty in decl.inputs { constrained_by_input.visit_ty(arg_ty); @@ -2675,11 +2630,12 @@ fn insert_late_bound_lifetimes( debug!("lifetime {:?} with id {:?} is late-bound", param.name.ident(), param.hir_id); - let inserted = map.late_bound.insert(param.hir_id); + let inserted = late_bound.insert(param_def_id); assert!(inserted, "visited lifetime {:?} twice", param.hir_id); } - return; + debug!(?late_bound); + return Some(tcx.arena.alloc(late_bound)); #[derive(Default)] struct ConstrainedCollector { diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index 4322440d6856b..34d107349e7c7 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -1364,7 +1364,6 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option( tcx: TyCtxt<'tcx>, - def_id: LocalDefId, generics: &'tcx hir::Generics<'tcx>, decl: &'tcx hir::FnDecl<'tcx>, ) -> Option { @@ -1373,14 +1372,9 @@ fn has_late_bound_regions<'tcx>(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option(tcx: TyCtxt<'tcx>, node: Node<'tcx>) -> Option match item.kind { hir::TraitItemKind::Fn(ref sig, _) => { - has_late_bound_regions(tcx, item.def_id, &item.generics, sig.decl) + has_late_bound_regions(tcx, &item.generics, sig.decl) } _ => None, }, Node::ImplItem(item) => match item.kind { hir::ImplItemKind::Fn(ref sig, _) => { - has_late_bound_regions(tcx, item.def_id, &item.generics, sig.decl) + has_late_bound_regions(tcx, &item.generics, sig.decl) } _ => None, }, Node::ForeignItem(item) => match item.kind { hir::ForeignItemKind::Fn(fn_decl, _, ref generics) => { - has_late_bound_regions(tcx, item.def_id, generics, fn_decl) + has_late_bound_regions(tcx, generics, fn_decl) } _ => None, }, Node::Item(item) => match item.kind { hir::ItemKind::Fn(ref sig, .., ref generics, _) => { - has_late_bound_regions(tcx, item.def_id, generics, sig.decl) + has_late_bound_regions(tcx, generics, sig.decl) } _ => None, }, @@ -1671,7 +1665,7 @@ fn generics_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Generics { params.push(opt_self); } - let early_lifetimes = early_bound_lifetimes_from_generics(tcx, hir_id.owner, ast_generics); + let early_lifetimes = early_bound_lifetimes_from_generics(tcx, ast_generics); params.extend(early_lifetimes.enumerate().map(|(i, param)| ty::GenericParamDef { name: param.name.ident().name, index: own_start + i as u32, @@ -2054,23 +2048,10 @@ fn impl_polarity(tcx: TyCtxt<'_>, def_id: DefId) -> ty::ImplPolarity { /// `resolve_lifetime::early_bound_lifetimes`. fn early_bound_lifetimes_from_generics<'a, 'tcx: 'a>( tcx: TyCtxt<'tcx>, - def_id: LocalDefId, generics: &'a hir::Generics<'a>, ) -> impl Iterator> + Captures<'tcx> { - let late_bound_map = if generics.params.is_empty() { - // This function may be called on `def_id == CRATE_DEF_ID`, - // which makes `is_late_bound_map` ICE. Don't even try if there - // is no generic parameter. - None - } else { - tcx.is_late_bound_map(def_id) - }; - let is_late_bound = move |hir_id| { - let id = tcx.hir().local_def_id(hir_id); - late_bound_map.map_or(false, |(_, set)| set.contains(&id)) - }; generics.params.iter().filter(move |param| match param.kind { - GenericParamKind::Lifetime { .. } => !is_late_bound(param.hir_id), + GenericParamKind::Lifetime { .. } => !tcx.is_late_bound(param.hir_id), _ => false, }) } @@ -2255,7 +2236,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP // have to be careful to only iterate over early-bound regions. let mut index = parent_count + has_own_self as u32 - + early_bound_lifetimes_from_generics(tcx, hir_id.owner, ast_generics).count() as u32; + + early_bound_lifetimes_from_generics(tcx, ast_generics).count() as u32; // Collect the predicates that were written inline by the user on each // type parameter (e.g., ``).