From f27bdf175034bd0455eb960fc0dc8262484f187b Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Mon, 31 Oct 2022 03:28:05 +0000
Subject: [PATCH] Collect late-bound regions from all closure parents in
`closure_mapping`
---
.../rustc_borrowck/src/region_infer/mod.rs | 2 +-
.../rustc_borrowck/src/universal_regions.rs | 82 ++++++++++---------
.../binder/nested-closures-regions.rs | 9 ++
.../binder/nested-closures-regions.stderr | 38 +++++++++
4 files changed, 91 insertions(+), 40 deletions(-)
create mode 100644 src/test/ui/closures/binder/nested-closures-regions.rs
create mode 100644 src/test/ui/closures/binder/nested-closures-regions.stderr
diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index 8b63294fbab..0e7f243bcf3 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -2314,7 +2314,7 @@ impl<'tcx> ClosureRegionRequirementsExt<'tcx> for ClosureRegionRequirements<'tcx
tcx,
closure_substs,
self.num_external_vids,
- tcx.typeck_root_def_id(closure_def_id),
+ closure_def_id.expect_local(),
);
debug!("apply_requirements: closure_mapping={:?}", closure_mapping);
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 51439dec440..0f300564c20 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -243,7 +243,7 @@ impl<'tcx> UniversalRegions<'tcx> {
tcx: TyCtxt<'tcx>,
closure_substs: SubstsRef<'tcx>,
expected_num_vars: usize,
- typeck_root_def_id: DefId,
+ closure_def_id: LocalDefId,
) -> IndexVec<RegionVid, ty::Region<'tcx>> {
let mut region_mapping = IndexVec::with_capacity(expected_num_vars);
region_mapping.push(tcx.lifetimes.re_static);
@@ -251,9 +251,13 @@ impl<'tcx> UniversalRegions<'tcx> {
region_mapping.push(fr);
});
- for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
- region_mapping.push(r);
- });
+ for_each_late_bound_region_in_scope(
+ tcx,
+ tcx.local_parent(closure_def_id),
+ |r| {
+ region_mapping.push(r);
+ },
+ );
assert_eq!(
region_mapping.len(),
@@ -341,9 +345,8 @@ impl<'tcx> UniversalRegions<'tcx> {
// tests, and the resulting print-outs include def-ids
// and other things that are not stable across tests!
// So we just include the region-vid. Annoying.
- let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
- for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
- err.note(&format!("late-bound region is {:?}", self.to_region_vid(r),));
+ for_each_late_bound_region_in_scope(tcx, def_id.expect_local(), |r| {
+ err.note(&format!("late-bound region is {:?}", self.to_region_vid(r)));
});
}
DefiningTy::Generator(def_id, substs, _) => {
@@ -356,9 +359,8 @@ impl<'tcx> UniversalRegions<'tcx> {
// FIXME: As above, we'd like to print out the region
// `r` but doing so is not stable across architectures
// and so forth.
- let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
- for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
- err.note(&format!("late-bound region is {:?}", self.to_region_vid(r),));
+ for_each_late_bound_region_in_scope(tcx, def_id.expect_local(), |r| {
+ err.note(&format!("late-bound region is {:?}", self.to_region_vid(r)));
});
}
DefiningTy::FnDef(def_id, substs) => {
@@ -749,28 +751,17 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
#[instrument(skip(self, indices))]
fn replace_late_bound_regions_with_nll_infer_vars(
&self,
- mut mir_def_id: LocalDefId,
+ mir_def_id: LocalDefId,
indices: &mut UniversalRegionIndices<'tcx>,
) {
- let typeck_root_def_id = self.tcx.typeck_root_def_id(mir_def_id.to_def_id());
-
- // Walk up the tree, collecting late-bound regions until we hit the typeck root
- loop {
- for_each_late_bound_region_defined_on(self.tcx, mir_def_id.to_def_id(), |r| {
- debug!(?r);
- if !indices.indices.contains_key(&r) {
- let region_vid = self.next_nll_region_var(FR);
- debug!(?region_vid);
- indices.insert_late_bound_region(r, region_vid.to_region_vid());
- }
- });
-
- if mir_def_id.to_def_id() == typeck_root_def_id {
- break;
- } else {
- mir_def_id = self.tcx.parent(mir_def_id.to_def_id()).expect_local();
+ for_each_late_bound_region_in_scope(self.tcx, mir_def_id, |r| {
+ debug!(?r);
+ if !indices.indices.contains_key(&r) {
+ let region_vid = self.next_nll_region_var(FR);
+ debug!(?region_vid);
+ indices.insert_late_bound_region(r, region_vid.to_region_vid());
}
- }
+ });
}
}
@@ -814,18 +805,31 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
}
}
-/// Iterates over the late-bound regions defined on fn_def_id and
-/// invokes `f` with the liberated form of each one.
-fn for_each_late_bound_region_defined_on<'tcx>(
+/// Iterates over the late-bound regions defined on fn_def_id and all of its
+/// parents, up to the typeck root, and invokes `f` with the liberated form
+/// of each one.
+fn for_each_late_bound_region_in_scope<'tcx>(
tcx: TyCtxt<'tcx>,
- fn_def_id: DefId,
+ mut mir_def_id: LocalDefId,
mut f: impl FnMut(ty::Region<'tcx>),
) {
- for bound_var in tcx.late_bound_vars(tcx.hir().local_def_id_to_hir_id(fn_def_id.expect_local()))
- {
- let ty::BoundVariableKind::Region(bound_region) = bound_var else { continue; };
- let liberated_region =
- tcx.mk_region(ty::ReFree(ty::FreeRegion { scope: fn_def_id, bound_region }));
- f(liberated_region);
+ let typeck_root_def_id = tcx.typeck_root_def_id(mir_def_id.to_def_id());
+
+ // Walk up the tree, collecting late-bound regions until we hit the typeck root
+ loop {
+ for bound_var in tcx.late_bound_vars(tcx.hir().local_def_id_to_hir_id(mir_def_id)) {
+ let ty::BoundVariableKind::Region(bound_region) = bound_var else { continue; };
+ let liberated_region = tcx.mk_region(ty::ReFree(ty::FreeRegion {
+ scope: mir_def_id.to_def_id(),
+ bound_region,
+ }));
+ f(liberated_region);
+ }
+
+ if mir_def_id.to_def_id() == typeck_root_def_id {
+ break;
+ } else {
+ mir_def_id = tcx.local_parent(mir_def_id);
+ }
}
}
diff --git a/src/test/ui/closures/binder/nested-closures-regions.rs b/src/test/ui/closures/binder/nested-closures-regions.rs
new file mode 100644
index 00000000000..6bfc6c80b78
--- /dev/null
+++ b/src/test/ui/closures/binder/nested-closures-regions.rs
@@ -0,0 +1,9 @@
+// check-pass
+
+#![feature(closure_lifetime_binder)]
+#![feature(rustc_attrs)]
+
+#[rustc_regions]
+fn main() {
+ for<'a> || -> () { for<'c> |_: &'a ()| -> () {}; };
+}
diff --git a/src/test/ui/closures/binder/nested-closures-regions.stderr b/src/test/ui/closures/binder/nested-closures-regions.stderr
new file mode 100644
index 00000000000..b385e0ed6e0
--- /dev/null
+++ b/src/test/ui/closures/binder/nested-closures-regions.stderr
@@ -0,0 +1,38 @@
+note: external requirements
+ --> $DIR/nested-closures-regions.rs:8:24
+ |
+LL | for<'a> || -> () { for<'c> |_: &'a ()| -> () {}; };
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: defining type: main::{closure#0}::{closure#0} with closure substs [
+ i8,
+ extern "rust-call" fn((&(),)),
+ (),
+ ]
+ = note: late-bound region is '_#4r
+ = note: late-bound region is '_#2r
+ = note: number of external vids: 3
+ = note: where '_#1r: '_#2r
+ = note: where '_#2r: '_#1r
+
+note: no external requirements
+ --> $DIR/nested-closures-regions.rs:8:5
+ |
+LL | for<'a> || -> () { for<'c> |_: &'a ()| -> () {}; };
+ | ^^^^^^^^^^^^^^^^
+ |
+ = note: defining type: main::{closure#0} with closure substs [
+ i8,
+ extern "rust-call" fn(()),
+ (),
+ ]
+ = note: late-bound region is '_#2r
+
+note: no external requirements
+ --> $DIR/nested-closures-regions.rs:7:1
+ |
+LL | fn main() {
+ | ^^^^^^^^^
+ |
+ = note: defining type: main
+