From 4427af082797a1e477781efd09947bb27d9b19c3 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Mon, 31 Oct 2022 21:18:17 +0000
Subject: [PATCH] Make external/local late-bound region registration more
explicit
---
.../rustc_borrowck/src/universal_regions.rs | 93 ++++++++++++++-----
1 file changed, 68 insertions(+), 25 deletions(-)
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 0f300564c20..482e10d520b 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -251,13 +251,9 @@ impl<'tcx> UniversalRegions<'tcx> {
region_mapping.push(fr);
});
- for_each_late_bound_region_in_scope(
- tcx,
- tcx.local_parent(closure_def_id),
- |r| {
- region_mapping.push(r);
- },
- );
+ for_each_late_bound_region_in_recursive_scope(tcx, tcx.local_parent(closure_def_id), |r| {
+ region_mapping.push(r);
+ });
assert_eq!(
region_mapping.len(),
@@ -345,7 +341,7 @@ 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.
- for_each_late_bound_region_in_scope(tcx, def_id.expect_local(), |r| {
+ for_each_late_bound_region_in_recursive_scope(tcx, def_id.expect_local(), |r| {
err.note(&format!("late-bound region is {:?}", self.to_region_vid(r)));
});
}
@@ -359,7 +355,7 @@ 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.
- for_each_late_bound_region_in_scope(tcx, def_id.expect_local(), |r| {
+ for_each_late_bound_region_in_recursive_scope(tcx, def_id.expect_local(), |r| {
err.note(&format!("late-bound region is {:?}", self.to_region_vid(r)));
});
}
@@ -430,10 +426,19 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
// fn foo<'a>() {
// let c = || { let x: &'a u32 = ...; }
// }
- self.infcx.replace_late_bound_regions_with_nll_infer_vars(
+ for_each_late_bound_region_in_recursive_scope(
+ self.infcx.tcx,
self.infcx.tcx.local_parent(self.mir_def.did),
- &mut indices,
+ |r| {
+ debug!(?r);
+ if !indices.indices.contains_key(&r) {
+ let region_vid = self.infcx.next_nll_region_var(FR);
+ debug!(?region_vid);
+ indices.insert_late_bound_region(r, region_vid.to_region_vid());
+ }
+ },
);
+
// Any regions created during the execution of `defining_ty` or during the above
// late-bound region replacement are all considered 'extern' regions
self.infcx.num_region_vars()
@@ -452,7 +457,14 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
);
// Converse of above, if this is a function/closure then the late-bound regions declared on its
// signature are local.
- self.infcx.replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices);
+ for_each_late_bound_region_in_item(self.infcx.tcx, self.mir_def.did, |r| {
+ debug!(?r);
+ if !indices.indices.contains_key(&r) {
+ let region_vid = self.infcx.next_nll_region_var(FR);
+ debug!(?region_vid);
+ indices.insert_late_bound_region(r, region_vid.to_region_vid());
+ }
+ });
let (unnormalized_output_ty, mut unnormalized_input_tys) =
inputs_and_output.split_last().unwrap();
@@ -695,7 +707,13 @@ trait InferCtxtExt<'tcx> {
where
T: TypeFoldable<'tcx>;
- fn replace_late_bound_regions_with_nll_infer_vars(
+ fn replace_late_bound_regions_with_nll_infer_vars_in_recursive_scope(
+ &self,
+ mir_def_id: LocalDefId,
+ indices: &mut UniversalRegionIndices<'tcx>,
+ );
+
+ fn replace_late_bound_regions_with_nll_infer_vars_in_item(
&self,
mir_def_id: LocalDefId,
indices: &mut UniversalRegionIndices<'tcx>,
@@ -749,12 +767,28 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
/// set of late-bound regions and checks for any that we have not yet seen, adding them to the
/// inputs vector.
#[instrument(skip(self, indices))]
- fn replace_late_bound_regions_with_nll_infer_vars(
+ fn replace_late_bound_regions_with_nll_infer_vars_in_recursive_scope(
&self,
mir_def_id: LocalDefId,
indices: &mut UniversalRegionIndices<'tcx>,
) {
- for_each_late_bound_region_in_scope(self.tcx, mir_def_id, |r| {
+ for_each_late_bound_region_in_recursive_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());
+ }
+ });
+ }
+
+ #[instrument(skip(self, indices))]
+ fn replace_late_bound_regions_with_nll_infer_vars_in_item(
+ &self,
+ mir_def_id: LocalDefId,
+ indices: &mut UniversalRegionIndices<'tcx>,
+ ) {
+ for_each_late_bound_region_in_item(self.tcx, mir_def_id, |r| {
debug!(?r);
if !indices.indices.contains_key(&r) {
let region_vid = self.next_nll_region_var(FR);
@@ -805,10 +839,10 @@ impl<'tcx> UniversalRegionIndices<'tcx> {
}
}
-/// Iterates over the late-bound regions defined on fn_def_id and all of its
+/// Iterates over the late-bound regions defined on `mir_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>(
+fn for_each_late_bound_region_in_recursive_scope<'tcx>(
tcx: TyCtxt<'tcx>,
mut mir_def_id: LocalDefId,
mut f: impl FnMut(ty::Region<'tcx>),
@@ -817,14 +851,7 @@ fn for_each_late_bound_region_in_scope<'tcx>(
// 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);
- }
+ for_each_late_bound_region_in_item(tcx, mir_def_id, &mut f);
if mir_def_id.to_def_id() == typeck_root_def_id {
break;
@@ -833,3 +860,19 @@ fn for_each_late_bound_region_in_scope<'tcx>(
}
}
}
+
+/// Iterates over the late-bound regions defined on `mir_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_item<'tcx>(
+ tcx: TyCtxt<'tcx>,
+ 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(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);
+ }
+}