Remove RCs from Borrows

Cargo.lock

@@ -1330,9 +1330,9 @@ dependencies = [
 
 [[package]]
 name = "git2"
-version = "0.13.14"
+version = "0.13.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "186dd99cc77576e58344ad614fa9bb27bad9d048f85de3ca850c1f4e8b048260"
+checksum = "1d250f5f82326884bd39c2853577e70a121775db76818ffa452ed1e80de12986"
 dependencies = [
  "bitflags",
  "libc",
@@ -1759,9 +1759,9 @@ dependencies = [
 
 [[package]]
 name = "libgit2-sys"
-version = "0.12.16+1.1.0"
+version = "0.12.18+1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f91b2f931ee975a98155195be8cd82d02e8e029d7d793d2bac1b8181ac97020"
+checksum = "3da6a42da88fc37ee1ecda212ffa254c25713532980005d5f7c0b0fbe7e6e885"
 dependencies = [
  "cc",
  "libc",
@@ -5346,7 +5346,7 @@ dependencies = [
  "chrono",
  "lazy_static",
  "matchers",
- "parking_lot 0.11.0",
+ "parking_lot 0.9.0",
  "regex",
  "serde",
  "serde_json",

compiler/rustc_mir/src/borrow_check/mod.rs

@@ -259,7 +259,7 @@ fn do_mir_borrowck<'a, 'tcx>(
 
     let regioncx = Rc::new(regioncx);
 
-    let flow_borrows = Borrows::new(tcx, &body, regioncx.clone(), Rc::clone(borrow_set))
+    let flow_borrows = Borrows::new(tcx, &body, &regioncx, &borrow_set)
         .into_engine(tcx, &body)
         .pass_name("borrowck")
         .iterate_to_fixpoint();
@@ -303,7 +303,7 @@ fn do_mir_borrowck<'a, 'tcx>(
                 regioncx: regioncx.clone(),
                 used_mut: Default::default(),
                 used_mut_upvars: SmallVec::new(),
-                borrow_set: borrow_set.clone(),
+                borrow_set: Rc::clone(&borrow_set),
                 dominators,
                 upvars: Vec::new(),
                 local_names: IndexVec::from_elem(None, &promoted_body.local_decls),
@@ -333,10 +333,10 @@ fn do_mir_borrowck<'a, 'tcx>(
         move_error_reported: BTreeMap::new(),
         uninitialized_error_reported: Default::default(),
         errors_buffer,
-        regioncx,
+        regioncx: Rc::clone(&regioncx),
         used_mut: Default::default(),
         used_mut_upvars: SmallVec::new(),
-        borrow_set,
+        borrow_set: Rc::clone(&borrow_set),
         dominators,
         upvars,
         local_names,

compiler/rustc_mir/src/dataflow/impls/borrows.rs

@@ -11,7 +11,6 @@ use crate::borrow_check::{
 use crate::dataflow::{self, fmt::DebugWithContext, GenKill};
 
 use std::fmt;
-use std::rc::Rc;
 
 rustc_index::newtype_index! {
     pub struct BorrowIndex {
@@ -30,11 +29,8 @@ pub struct Borrows<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     body: &'a Body<'tcx>,
 
-    borrow_set: Rc<BorrowSet<'tcx>>,
+    borrow_set: &'a BorrowSet<'tcx>,
     borrows_out_of_scope_at_location: FxHashMap<Location, Vec<BorrowIndex>>,
-
-    /// NLL region inference context with which NLL queries should be resolved
-    _nonlexical_regioncx: Rc<RegionInferenceContext<'tcx>>,
 }
 
 struct StackEntry {
@@ -47,12 +43,12 @@ struct OutOfScopePrecomputer<'a, 'tcx> {
     visited: BitSet<mir::BasicBlock>,
     visit_stack: Vec<StackEntry>,
     body: &'a Body<'tcx>,
-    regioncx: Rc<RegionInferenceContext<'tcx>>,
+    regioncx: &'a RegionInferenceContext<'tcx>,
     borrows_out_of_scope_at_location: FxHashMap<Location, Vec<BorrowIndex>>,
 }
 
 impl<'a, 'tcx> OutOfScopePrecomputer<'a, 'tcx> {
-    fn new(body: &'a Body<'tcx>, regioncx: Rc<RegionInferenceContext<'tcx>>) -> Self {
+    fn new(body: &'a Body<'tcx>, regioncx: &'a RegionInferenceContext<'tcx>) -> Self {
         OutOfScopePrecomputer {
             visited: BitSet::new_empty(body.basic_blocks().len()),
             visit_stack: vec![],
@@ -147,10 +143,10 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     crate fn new(
         tcx: TyCtxt<'tcx>,
         body: &'a Body<'tcx>,
-        nonlexical_regioncx: Rc<RegionInferenceContext<'tcx>>,
-        borrow_set: Rc<BorrowSet<'tcx>>,
+        nonlexical_regioncx: &'a RegionInferenceContext<'tcx>,
+        borrow_set: &'a BorrowSet<'tcx>,
     ) -> Self {
-        let mut prec = OutOfScopePrecomputer::new(body, nonlexical_regioncx.clone());
+        let mut prec = OutOfScopePrecomputer::new(body, nonlexical_regioncx);
         for (borrow_index, borrow_data) in borrow_set.iter_enumerated() {
             let borrow_region = borrow_data.region.to_region_vid();
             let location = borrow_data.reserve_location;
@@ -163,7 +159,6 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
             body,
             borrow_set,
             borrows_out_of_scope_at_location: prec.borrows_out_of_scope_at_location,
-            _nonlexical_regioncx: nonlexical_regioncx,
         }
     }