From 98a11e01e5f5bf274451320834ea85f9cbd03b92 Mon Sep 17 00:00:00 2001
From: Cameron Steffen <cam.steffen94@gmail.com>
Date: Mon, 19 Apr 2021 15:39:19 -0500
Subject: [PATCH 1/2] Remove closure_tree
---
compiler/rustc_middle/src/middle/region.rs | 31 ----------------------
compiler/rustc_passes/src/region.rs | 15 +----------
2 files changed, 1 insertion(+), 45 deletions(-)
diff --git a/compiler/rustc_middle/src/middle/region.rs b/compiler/rustc_middle/src/middle/region.rs
index 5440e63543d..f44267a404b 100644
--- a/compiler/rustc_middle/src/middle/region.rs
+++ b/compiler/rustc_middle/src/middle/region.rs
@@ -235,18 +235,6 @@ pub struct ScopeTree {
/// escape into 'static and should have no local cleanup scope.
rvalue_scopes: FxHashMap<hir::ItemLocalId, Option<Scope>>,
- /// Encodes the hierarchy of fn bodies. Every fn body (including
- /// closures) forms its own distinct region hierarchy, rooted in
- /// the block that is the fn body. This map points from the ID of
- /// that root block to the ID of the root block for the enclosing
- /// fn, if any. Thus the map structures the fn bodies into a
- /// hierarchy based on their lexical mapping. This is used to
- /// handle the relationships between regions in a fn and in a
- /// closure defined by that fn. See the "Modeling closures"
- /// section of the README in infer::region_constraints for
- /// more details.
- closure_tree: FxHashMap<hir::ItemLocalId, hir::ItemLocalId>,
-
/// If there are any `yield` nested within a scope, this map
/// stores the `Span` of the last one and its index in the
/// postorder of the Visitor traversal on the HIR.
@@ -356,23 +344,6 @@ impl ScopeTree {
self.destruction_scopes.get(&n).cloned()
}
- /// Records that `sub_closure` is defined within `sup_closure`. These IDs
- /// should be the ID of the block that is the fn body, which is
- /// also the root of the region hierarchy for that fn.
- pub fn record_closure_parent(
- &mut self,
- sub_closure: hir::ItemLocalId,
- sup_closure: hir::ItemLocalId,
- ) {
- debug!(
- "record_closure_parent(sub_closure={:?}, sup_closure={:?})",
- sub_closure, sup_closure
- );
- assert!(sub_closure != sup_closure);
- let previous = self.closure_tree.insert(sub_closure, sup_closure);
- assert!(previous.is_none());
- }
-
pub fn record_var_scope(&mut self, var: hir::ItemLocalId, lifetime: Scope) {
debug!("record_var_scope(sub={:?}, sup={:?})", var, lifetime);
assert!(var != lifetime.item_local_id());
@@ -474,7 +445,6 @@ impl<'a> HashStable<StableHashingContext<'a>> for ScopeTree {
ref var_map,
ref destruction_scopes,
ref rvalue_scopes,
- ref closure_tree,
ref yield_in_scope,
} = *self;
@@ -488,7 +458,6 @@ impl<'a> HashStable<StableHashingContext<'a>> for ScopeTree {
var_map.hash_stable(hcx, hasher);
destruction_scopes.hash_stable(hcx, hasher);
rvalue_scopes.hash_stable(hcx, hasher);
- closure_tree.hash_stable(hcx, hasher);
yield_in_scope.hash_stable(hcx, hasher);
}
}
diff --git a/compiler/rustc_passes/src/region.rs b/compiler/rustc_passes/src/region.rs
index b532021bed2..14a373c5942 100644
--- a/compiler/rustc_passes/src/region.rs
+++ b/compiler/rustc_passes/src/region.rs
@@ -23,14 +23,6 @@ use std::mem;
#[derive(Debug, Copy, Clone)]
pub struct Context {
- /// The root of the current region tree. This is typically the id
- /// of the innermost fn body. Each fn forms its own disjoint tree
- /// in the region hierarchy. These fn bodies are themselves
- /// arranged into a tree. See the "Modeling closures" section of
- /// the README in `rustc_trait_selection::infer::region_constraints`
- /// for more details.
- root_id: Option<hir::ItemLocalId>,
-
/// The scope that contains any new variables declared, plus its depth in
/// the scope tree.
var_parent: Option<(Scope, ScopeDepth)>,
@@ -743,11 +735,6 @@ impl<'tcx> Visitor<'tcx> for RegionResolutionVisitor<'tcx> {
let outer_pessimistic_yield = mem::replace(&mut self.pessimistic_yield, false);
self.terminating_scopes.insert(body.value.hir_id.local_id);
- if let Some(root_id) = self.cx.root_id {
- self.scope_tree.record_closure_parent(body.value.hir_id.local_id, root_id);
- }
- self.cx.root_id = Some(body.value.hir_id.local_id);
-
self.enter_scope(Scope { id: body.value.hir_id.local_id, data: ScopeData::CallSite });
self.enter_scope(Scope { id: body.value.hir_id.local_id, data: ScopeData::Arguments });
@@ -824,7 +811,7 @@ fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
tcx,
scope_tree: ScopeTree::default(),
expr_and_pat_count: 0,
- cx: Context { root_id: None, parent: None, var_parent: None },
+ cx: Context { parent: None, var_parent: None },
terminating_scopes: Default::default(),
pessimistic_yield: false,
fixup_scopes: vec![],
From c9c14d0c1f04f888fbd4ec8b254b61fff84db7d4 Mon Sep 17 00:00:00 2001
From: Cameron Steffen <cam.steffen94@gmail.com>
Date: Mon, 19 Apr 2021 15:40:05 -0500
Subject: [PATCH 2/2] Small refactor
---
compiler/rustc_trait_selection/src/traits/object_safety.rs | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index b5a458db607..ac5ec24eeee 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -439,8 +439,7 @@ fn virtual_call_violation_for_method<'tcx>(
return Some(MethodViolationCode::WhereClauseReferencesSelf);
}
- let receiver_ty =
- tcx.liberate_late_bound_regions(method.def_id, sig.map_bound(|sig| sig.inputs()[0]));
+ let receiver_ty = tcx.liberate_late_bound_regions(method.def_id, sig.input(0));
// Until `unsized_locals` is fully implemented, `self: Self` can't be dispatched on.
// However, this is already considered object-safe. We allow it as a special case here.