Merging upstream version 1.67.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 96 insertions, 37 deletions

diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index 2beb5e0ab..a4a0c5b90 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -22,7 +22,9 @@ use rustc_hir::{BodyOwnerKind, HirId};
 use rustc_index::vec::{Idx, IndexVec};
 use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin};
 use rustc_middle::ty::fold::TypeFoldable;
-use rustc_middle::ty::{self, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt};
+use rustc_middle::ty::{
+    self, DefIdTree, InlineConstSubsts, InlineConstSubstsParts, RegionVid, Ty, TyCtxt,
+};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use std::iter;
 
@@ -241,7 +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);
@@ -249,7 +251,7 @@ impl<'tcx> UniversalRegions<'tcx> {
             region_mapping.push(fr);
         });
 
-        for_each_late_bound_region_defined_on(tcx, typeck_root_def_id, |r| {
+        for_each_late_bound_region_in_recursive_scope(tcx, tcx.local_parent(closure_def_id), |r| {
             region_mapping.push(r);
         });
 
@@ -339,9 +341,8 @@ 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_recursive_scope(tcx, def_id.expect_local(), |r| {
+                    err.note(&format!("late-bound region is {:?}", self.to_region_vid(r)));
                 });
             }
             DefiningTy::Generator(def_id, substs, _) => {
@@ -354,9 +355,8 @@ 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_recursive_scope(tcx, def_id.expect_local(), |r| {
+                    err.note(&format!("late-bound region is {:?}", self.to_region_vid(r)));
                 });
             }
             DefiningTy::FnDef(def_id, substs) => {
@@ -421,13 +421,24 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             first_extern_index
         } else {
             // If this is a closure, generator, or inline-const, then the late-bound regions from the enclosing
-            // function are actually external regions to us. For example, here, 'a is not local
+            // function/closures are actually external regions to us. For example, here, 'a is not local
             // to the closure c (although it is local to the fn foo):
             // fn foo<'a>() {
             //     let c = || { let x: &'a u32 = ...; }
             // }
-            self.infcx
-                .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices);
+            for_each_late_bound_region_in_recursive_scope(
+                self.infcx.tcx,
+                self.infcx.tcx.local_parent(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());
+                    }
+                },
+            );
+
             // 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()
@@ -444,12 +455,16 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
             bound_inputs_and_output,
             &mut indices,
         );
-        // Converse of above, if this is a function then the late-bound regions declared on its
-        // signature are local to the fn.
-        if self.mir_def.did.to_def_id() == typeck_root_def_id {
-            self.infcx
-                .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices);
-        }
+        // Converse of above, if this is a function/closure then the late-bound regions declared on its
+        // signature are local.
+        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();
@@ -572,9 +587,9 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         let typeck_root_def_id = tcx.typeck_root_def_id(self.mir_def.did.to_def_id());
         let identity_substs = InternalSubsts::identity_for_item(tcx, typeck_root_def_id);
         let fr_substs = match defining_ty {
-            DefiningTy::Closure(_, ref substs)
-            | DefiningTy::Generator(_, ref substs, _)
-            | DefiningTy::InlineConst(_, ref substs) => {
+            DefiningTy::Closure(_, substs)
+            | DefiningTy::Generator(_, substs, _)
+            | DefiningTy::InlineConst(_, substs) => {
                 // In the case of closures, we rely on the fact that
                 // the first N elements in the ClosureSubsts are
                 // inherited from the `typeck_root_def_id`.
@@ -692,7 +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>,
@@ -746,13 +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_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>,
     ) {
-        let typeck_root_def_id = self.tcx.typeck_root_def_id(mir_def_id.to_def_id());
-        for_each_late_bound_region_defined_on(self.tcx, typeck_root_def_id, |r| {
+        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);
@@ -803,21 +839,44 @@ 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 `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_recursive_scope<'tcx>(
     tcx: TyCtxt<'tcx>,
-    fn_def_id: DefId,
+    mut mir_def_id: LocalDefId,
     mut f: impl FnMut(ty::Region<'tcx>),
 ) {
-    if let Some(late_bounds) = tcx.is_late_bound_map(fn_def_id.expect_local()) {
-        for &region_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: fn_def_id,
-                bound_region: ty::BoundRegionKind::BrNamed(region_def_id.to_def_id(), name),
-            }));
-            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_each_late_bound_region_in_item(tcx, mir_def_id, &mut f);
+
+        if mir_def_id.to_def_id() == typeck_root_def_id {
+            break;
+        } else {
+            mir_def_id = tcx.local_parent(mir_def_id);
         }
     }
 }
+
+/// 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>),
+) {
+    if !tcx.def_kind(mir_def_id).is_fn_like() {
+        return;
+    }
+
+    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);
+    }
+}