Auto merge of #90281 - xldenis:public-borrow-set, r=nikomatsakis

Add BorrowSet to public api

This PR adds `BorrowSet` to the public api so that verification tools can obtain the activation and reservation points of two phase borrows without having to redo calculations themselves (and thus potentially differently from rustc).

Turns out we already can obtain `MoveData` thanks to the public `HasMoveData` trait, so constructing a `BorrowSet` should not provide much of an issue. However, I can't speak to the soundness of this approach, is it safe to take an under-approximation of `MoveData`?

r? `@nikomatsakis`

compiler/rustc_borrowck/src/borrow_set.rs

@@ -12,22 +12,22 @@ use rustc_mir_dataflow::move_paths::MoveData;
 use std::fmt;
 use std::ops::Index;
 
-crate struct BorrowSet<'tcx> {
+pub struct BorrowSet<'tcx> {
     /// The fundamental map relating bitvector indexes to the borrows
     /// in the MIR. Each borrow is also uniquely identified in the MIR
     /// by the `Location` of the assignment statement in which it
     /// appears on the right hand side. Thus the location is the map
     /// key, and its position in the map corresponds to `BorrowIndex`.
-    crate location_map: FxIndexMap<Location, BorrowData<'tcx>>,
+    pub location_map: FxIndexMap<Location, BorrowData<'tcx>>,
 
     /// Locations which activate borrows.
     /// NOTE: a given location may activate more than one borrow in the future
     /// when more general two-phase borrow support is introduced, but for now we
     /// only need to store one borrow index.
-    crate activation_map: FxHashMap<Location, Vec<BorrowIndex>>,
+    pub activation_map: FxHashMap<Location, Vec<BorrowIndex>>,
 
     /// Map from local to all the borrows on that local.
-    crate local_map: FxHashMap<mir::Local, FxHashSet<BorrowIndex>>,
+    pub local_map: FxHashMap<mir::Local, FxHashSet<BorrowIndex>>,
 
     crate locals_state_at_exit: LocalsStateAtExit,
 }
@@ -43,27 +43,27 @@ impl<'tcx> Index<BorrowIndex> for BorrowSet<'tcx> {
 /// Location where a two-phase borrow is activated, if a borrow
 /// is in fact a two-phase borrow.
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
-crate enum TwoPhaseActivation {
+pub enum TwoPhaseActivation {
     NotTwoPhase,
     NotActivated,
     ActivatedAt(Location),
 }
 
 #[derive(Debug, Clone)]
-crate struct BorrowData<'tcx> {
+pub struct BorrowData<'tcx> {
     /// Location where the borrow reservation starts.
     /// In many cases, this will be equal to the activation location but not always.
-    crate reserve_location: Location,
+    pub reserve_location: Location,
     /// Location where the borrow is activated.
-    crate activation_location: TwoPhaseActivation,
+    pub activation_location: TwoPhaseActivation,
     /// What kind of borrow this is
-    crate kind: mir::BorrowKind,
+    pub kind: mir::BorrowKind,
     /// The region for which this borrow is live
-    crate region: RegionVid,
+    pub region: RegionVid,
     /// Place from which we are borrowing
-    crate borrowed_place: mir::Place<'tcx>,
+    pub borrowed_place: mir::Place<'tcx>,
     /// Place to which the borrow was stored
-    crate assigned_place: mir::Place<'tcx>,
+    pub assigned_place: mir::Place<'tcx>,
 }
 
 impl<'tcx> fmt::Display for BorrowData<'tcx> {
@@ -78,7 +78,7 @@ impl<'tcx> fmt::Display for BorrowData<'tcx> {
     }
 }
 
-crate enum LocalsStateAtExit {
+pub enum LocalsStateAtExit {
     AllAreInvalidated,
     SomeAreInvalidated { has_storage_dead_or_moved: BitSet<Local> },
 }

compiler/rustc_borrowck/src/lib.rs

@@ -64,7 +64,7 @@ use facts::AllFacts;
 
 use self::path_utils::*;
 
-mod borrow_set;
+pub mod borrow_set;
 mod borrowck_errors;
 mod constraint_generation;
 mod constraints;